`# @@@ @@@@< =Q EN DB      & . 6QF oa n  7=A Cms L Adam19988 Adam20011  Andreuccetti1991 Aschoff2000 Austin1998: Berber2000:! Bini1984 Bini1991t Block1999 Bluemke1996 Bluemke2000 Boaz1998Boitnott2000 Botnar19988 Bouvet20010 Brennan1997 Brewer1998:Brucksch1998 Bucker19989 Butts1999#Calliada2001# Campani2001 Capps1998Catalano2000 Cha2000Chambers1996 Choti1996 Choti2000 Christians2001 Chung1997 Chung1998Clampitt1998 Daniel1999: Debatin1998 Dubno1998 Duerk1997 Duerk1998 Duerk2000 Dutkowski2000 Easter20010 Eng2000 Engelmann2000 Engle2000Esposito2000 Farina1998 Fishman1996 Fishman2000 Foley2001 Foroutani2000Forsberg20011Gamagami20011 Garland2000 Gazelle1998 Gazelle1999  Gertner1998  Gilbert1985  Gilbert1997Goldberg1999Goldberg2001#Goldberg2001Grosskortenhaus2001 Gruenberger2000 Gunther1998 Gunther1999 Gunther2001 Gurney2000: Haaga1998 Haage2001 Hassanein2001 Heschel1999 Heshel19989 Hoddick1985 Horton20000 Hunter19989 Hunter19999! Ignesti1984 Ignesti1991 James2001 Jesberger2000 Jourdan2000 Junginger2000 Kelcz2000 King20000 Kinney20010 Kolecki1998 Kuszyk1996 Kuszyk2000 Lassman2000 Lee2000 Leung1997 Lewin1997 Lewin1998 Lewin2000 Liu2001#Livraghi2001 Lu20000 Lufkin1997 Magee2000 Mahvi2000 Markhardt2000McKinnon19959 McLoughlin1995# Meloni2001 Merton20010!Millanta1984 Morris20000 Nassir20000 Needleman2001 Neifeld1998 Nelson20010Nunziata2000! Olmi19841 Olmi19919 Onik19859 Oshiro1997# Pallavicini2001 Pease1997 Pitt20011 Popken2000Prescher1998 Pretorius2001 Quebbeman2001 Quiroz20012 Rafie2000 Raman2000 Rau1998 Rau1999 Rawool20010# Ricci2001 Rogers20000 Rose2001# Rossi2001! Rubino19848 Rubinsky1985 Rubinsky1997 Ryan20000 Saliken1995 Sayre2000Schirmer1998 Seifert2000Sellhaus2001 Sherar1998 Sheth2000 Shore1999 Siani2000 Sinha1997 Sinha1997 Siperstein2000Sitzmann1996Speetzen1998Speetzen1999 Steiner1998 Straub19999 Tacke1998 Tacke1999 Tacke2001 Temple19955 Urban1996 van Vaals1998! Vanni1984 Vanni1991Vodopich2000 Wallace2001 Walovitch1999 Warner20000 Wilson1998 Wiseman1995 Wong19971  Worthington1998 Zhao20000 Zimmermann1998   AuthorsJournals Keywords                                <  l Adam, G.Andreuccetti, D Aschoff, A.J. Austin, R.S. Berber, E. Bini, M Bini, M. G. Block, W.F. Bluemke, D.A. Boaz, T.L.Boitnott, J.K. Botnar, R. Bouvet, M. Brennan, K.M. Brewer, W.H. Brucksch, K. Bucker, A. Butts, K. Calliada, F. Campani, R. Capps, G.W. Catalano, O. Cha, C. H. Cha, C.H.Chambers, T.P. Choti, M.A.Christians, K. K. Chung, Y.C.Clampitt, M.E. Daniel, B.L. Debatin, J.F. Dubno, B. Duerk, J.L. Dutkowski, P. Easter, D. W. Easter, D.W. Eng, J. Engelmann, R. Engle, K.L. Esposito, M. Farina, Dino Fishman, E.K. Foley, W. D. Foroutani, A. Forsberg, F.Gamagami, R. A.Gamagami, R.A. Garland, A.M. Gazelle, G.S. Gertner, M.R. Gilbert, J.C.Goldberg, B.B.Goldberg, S. N.Goldberg, S.N.Grosskortenhaus, S.Gruenberger, T. Gunther, R.W. Gurney, J. M. Gurney, J.M. Haaga, J.R. Haage, P.Hassanein, T. I.Hassanein, T.I. Heschel, I. Heshel, I. Hoddick, W.K. Horton, K.M. Hunter, D.W. Ignesti, A Ignesti, A. James, G. M. James, G.M.Jesberger, J.A. Jourdan, J.L. Junginger, T. Kelcz, F. King, J. Kinney, T. B. Kinney, T.B. Kolecki, R. Kuszyk, B.S. Lassman, C.Lee, F. T., Jr.Lee, F.T., Jr. Leung, P.P. Lewin, J.S. Liu, J.B. Livraghi, T. Lu, D.S. Lufkin, R. Magee, C.A. Mahvi, D. M. Mahvi, D.M.Markhardt, B. K.Markhardt, B.K. McKinnon, G.McLoughlin, R.F. Meloni, M. F. Merton, D.A. Millanta, L. Morris, D.L. Nassir, F. Needleman, L. Neifeld, J.P. Nelson, T. R. Nelson, T.R. Nunziata, A. Olmi, R Olmi, R. Onik, G.M. Oshiro, T.Pallavicini, D. Pease, G.R. Pitt, H. A. Popken, F. Prescher, A.Pretorius, D. H.Pretorius, D.H.Quebbeman, E. J. Quiroz, F. A. Rafie, N. Raman, S.S. Rau, G. Rawool, N.M. Ricci, P. Rogers, S.J. Rose, S. C. Rose, S.C. Rossi, M. Rubino, N. Rubinsky, B. Ryan, T.L. Saliken, J.F. Sayre, J. Schirmer, B. Seifert, J.K. Sellhaus, B. Sherar, M.D. Sheth, S. Shore, M.T. Siani, A. Sinha, S. Sinha, U.Siperstein, A.E.Sitzmann, J.V. Speetzen, R. Steiner, P. Straub, J.A. Tacke, J. Temple, W. Urban, B.A.van Vaals, J.J. Vanni, R Vanni, R.Vodopich, D.J.Wallace, J. R.Walovitch, R.C. Warner, T. F. Warner, T.F. Wilson, B.C. Wiseman, D. Wong, S.T.Worthington, A.E. Zhao, J.Zimmermann, G.G.  T Abdom.ImagingAJR Am J RoentgenolAJR Am.J.Roentgenol.(%AJR.American Journal of RoentgenologyArchives of Surgery CryobiologyIEEE Trans Biomed EngInt J HyperthermiaInvestigative RadiologyJ Gastrointest SurgJ Vasc Interv RadiolJ.Magn Reson.ImagingJ.Ultrasound Med.J.Vasc.Interv.Radiol.(%Journal of Magnetic Resonance Imaging Magnetic Resonance Imaging$Magnetic Resonance in Medicine Radiology Seminars in Surgical Oncology Sensors$!Surgical Clinics of North AmericaSurgical EndoscopyN$ Ultrasound in Medicine & Biology   w*Acrylic Resins$*Adenocarcinoma/pa [Pathology]$ *Adenocarcinoma/ra [Radiography] *Adenocarcinoma/su [Surgery]p($*Adenocarcinoma/us [Ultrasonography],(*Adipose Tissue/ah [Anatomy & Histology]$!*Body Temperature/ph [Physiology]*Catheter Ablation$*Catheter Ablation/mt [Methods]*Contrast Media *Cryosurgery$!*Cryosurgery/is [Instrumentation]*Cryosurgery/mt [Methods] *Cryotherapy40*Digestive System Neoplasms/us [Ultrasonography],)*Echo-Planar Imaging/is [Instrumentation]$!*Echo-Planar Imaging/mt [Methods]*Electrocoagulation*Electromagnetic Fields*Electromagnetics *Freezing*Gels*Hepatectomy/mt [Methods]*Hyperthermia, Induced*Hyperthermia,Induced$*Image Enhancement/mt [Methods] *Imaging, Three-Dimensional$!*Intraoperative Care/mt [Methods] *Laparoscopy0**Liver Neoplasms,Experimental/su [Surgery]$*Liver Neoplasms/di [Diagnosis]$*Liver Neoplasms/pa [Pathology]$!*Liver Neoplasms/ra [Radiography]$*Liver Neoplasms/sc [Secondary] *Liver Neoplasms/su [Surgery] *Liver Neoplasms/th [Therapy](%*Liver Neoplasms/us [Ultrasonography]$*Liver/ah [Anatomy & Histology]is*Liver/pa [Pathology]*Liver/ph [Physiology]*Liver/ra [Radiography] [*Liver/su [Surgery]y] *Liver/us [Ultrasonography]th *Magnetic Resonance Imagingog,(*Magnetic Resonance Imaging/mt [Methods] *Microspheres*Models, Structural,)*Muscle,Skeletal/ah [Anatomy & Histology] *Muscle,Skeletal/su [Surgery] *Necrosis *Neoplasm Recurrence,Local,'*Neuroendocrine Tumors/ra [Radiography](#*Neuroendocrine Tumors/su [Surgery]ph0-*Postoperative Complications/ra [Radiography]*Radiology,Interventional *Temperature *Tomography, X-Ray Computed *Tomography,X-Ray Computed[Su*Ultrasonography$ *Ultrasonography, Interventional0 (Boron Compounds)0 (Contrast Media)e I 0 (Glass) 0 (Silicates)7727-37-9 (Nitrogen)AdenocarcinomaRay Adenocarcinoma/su [Surgery]administration & dosageYAdultadverse effectsAgedtAir analysisanatomy & histologyes Animaly & ArtifactsBias (Epidemiology),&Bile Ducts,Intrahepatic/pa [Pathology]0,Biliary Tract Neoplasms/us [Ultrasonography] Biophysicsblood0-Blood Loss,Surgical/pc [Prevention & Control] Blood Vessels/pa [Pathology]Body TemperatureBoron Compounds Calibration@=Carcinoma, Hepatocellular/pathology/*surgery/*ultrasonographyD>Carcinoma, Hepatocellular/radiography/*surgery/ultrasonographyCarcinoma,Hepatocellular,'Carcinoma,Hepatocellular/di [Diagnosis](%Carcinoma,Hepatocellular/su [Surgery]Catheter Ablation Catheter Ablation/*methods CattleticColorectal Neoplasms$Colorectal Neoplasms/*pathology(#Colorectal Neoplasms/pa [Pathology],)Colorectal Neoplasms/us [Ultrasonography]Comparative Study complicationsContrast Mediaudy Cryosurgeryns$ Cryosurgery/ae [Adverse Effects]gCryosurgery/mt [Methods] Cryotherapy diagnosisDiagnosis,Differentialdiagnostic useionDisease Models,AnimalDogsElectric ConductivityElectric Impedancee I ElectrodesmpeEquipment Design,)Esophageal Neoplasms/us [Ultrasonography] Ethanolt Evaluation StudiesFeasibility Studies Femalest    lVPCha,C.H. Lee,F.T.,Jr. Gurney,J.M. Markhardt,B.K. Warner,T.F. Kelcz,F. Mahvi,D.M. 2000TNCT versus sonography for monitoring radiofrequency ablation in a porcine liver,%AJR.American Journal of RoentgenologyF 1753705-711p 9/2000&CT and US imaging vs. pathologyJ27$*Hepatectomy/mt [Methods] *Intraoperative Care/mt [Methods] *Liver/ra [Radiography] *Liver/us [Ultrasonography] *Tomography,X-Ray Computed Animal Catheter Ablation Comparative Study Liver Liver/su [Surgery] methods Support,Non-U.S.Gov't surgery Swine Temperature United States ArtifactspjOBJECTIVE: The objective of this study was to compare CT and sonography for monitoring radiofrequency (RF) lesions in porcine livers. SUBJECTS AND METHODS: RF lesions (n = 12) were created in three pig livers by applying 13 min of current to a multielectrode RF probe with a target temperature of 95 degrees C. Helical unenhanced CT and corresponding axial sonography were performed before ablation, at 2 min, 8 min, and immediately after ablation. Contrast-enhanced CT was performed after ablation. CT scans and sonograms were evaluated by blinded observers for conspicuity of the RF lesion, edge detection (visibility of liver-lesion interface), and artifacts. Hounsfield units were recorded at every time interval, and radiologic-pathologic correlation for lesion size and configuration was performed. RESULTS: Mean size of RF lesions was 3. 03 +/- 0.9 cm. On CT, RF lesions had consistently lower attenuation values than surrounding liver (22.2 H lower than liver at 8 min, p < 0.0001). Echogenicity was variable with sonography (hypoechoic = 59%, hyperechoic = 25%, isoechoic = 16%). Unenhanced CT significantly improved conspicuity, edge detection of RF lesions, and decreased artifacts compared with sonography (p < 0.05). Contrast-enhanced CT improved RF lesion detection, border discrimination, and artifacts compared with sonography (p < 0.05). Unenhanced CT had the best correlation to pathologic size (r = 0.74), followed by contrast-enhanced CT (r = 0.72) and sonography (r = 0.56). Contrast-enhanced CT best correlated with lesion shape, but slightly overestimated size because of areas of ischemia peripheral to the RF lesion. CONCLUSION: In this animal model, unenhanced CT was an effective way to monitor RF ablation compared with sonography because of increased lesion discrimination, reproducible decreased attenuation during ablation, and improved correlation to pathologic sizezsDB - MEDLINE UI - 20410984 IN - Department of Surgery, University of Wisconsin, 600 Highland Ave., Madison, WI 53792-3252, USA JC - 3ae, 3AE, 3AE, 7708173 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 20001003 Revised: 20010323. Entry Week: 20001003 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0361-803X:3http://www.ajronline.org/cgi/content/full/175/3/705noma, Hepatocellular/radiography/*surgery/ultrasonographyZTThe role of contrast-enhanced sonography for radiofrequency ablation of liver tumorsNGLiu,J.B. Goldberg,B.B. Merton,D.A. Rawool,N.M. Needleman,L. Forsberg,F.A 2001 5/20012+Liver methods Rabbits therapy United StatesUI - 21241362 LA - eng PT - Journal Article DA - 20010509 IS - 0278-4297 SB - IM CY - United States JC - KBU RefMgr field[1]: Journal RefMgr field[8]: Not in File517-523J.Ultrasound Med.205^XOBJECTIVE: To assess the feasibility and usefulness of contrast- enhanced sonography for tumor detection and guidance of liver VX2 tumor ablation and to evaluate post radiofrequency ablation effectiveness. METHODS: VX2 tumors were implanted into the livers of 6 rabbits. Both conventional and harmonic gray scale and power Doppler imaging were performed with a commercially available scanner to evaluate the liver tumors before and after intravenous injection of a sonographic contrast agent before and after radiofrequency ablation. Contrast-enhanced imaging was used to detect the tumors before ablation, to guide needle insertion, and to measure the ablation sites after radiofrequency ablation. Pathologic examination was performed for comparison. RESULTS: Three tumors were seen without contrast enhancement, whereas 10 tumors (<1 cm) were detected with contrast enhancement. Intentionally, 2 tumors were completely ablated and 5 tumors were partially ablated. In 3 cases, incompletely ablated tumors could only be identified on contrast-enhanced Doppler imaging by enhancing the detection of residual tumor vascularity. There was excellent concordance between sonographic imaging and gross pathologic findings. CONCLUSIONS: Contrast-enhanced sonographic imaging appears useful for detection of liver tumors and for guiding and monitoring tumor ablation therapies'jdDepartment of Radiology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania 19107, USA173 PM:11345109 @@ #   !ish; England] TY - JOURhahttp://www.sciencedirect.com/science/article/B6WVB-43G4DGK-3NF/1/9e92aca9690dd69756a10a1a285e88f5t[8]: Not in File 64-69J.Magn Reson.Imaging81,%In vivo rabbit, titanium alloy probe. The purpose of this study was to determine the suitability of MRI to accurately detect radiofrequency (RF) thermoablative lesions created under MR guidance. In vivo RF lesions were created in the livers of six New Zealand White rabbits using a 2-mm-diameter titanium alloy RF electrode with a 20-mm exposed tip and a 50-W RF generator. This was performed using a 0.2T clinical C-arm MR imager for guidance and monitoring. Each animal was sacrificed and gross evaluation was performed. Histologic correlation was performed on the first two animals. The MR-compatible RF electrode was easily identified on rapid gradient-echo images used to guide electrode placement. A single lesion was created in each rabbit liver. Lesions ranged from approximately 10 to 17 mm in diameter (mean, 13.5 mm). T2-weighted and short T1 inversion recovery (STIR) images demonstrated lesions ranging in diameter from 12 to 18 mm (mean, 14.6 mm). Lesion dimensions determined from images closely correlated with those determined at gross examination with the discrepancy never exceeding 2 mm, for an r2 value of .87. MRI performed at the time of MR-guided RF ablation accurately demonstrated created lesions. This modality may provide a new option for the treatment of local and regional neoplastic disease'piDepartment of Radiology, University Hospitals of Cleveland/Case Western Reserve University, OH 44106, USA141 PM:9500262  " 306d^Intraoperative monitoring and postoperative imaging of hepatic cryosurgery. [Review] [37 refs]6/Brewer,W.H. Austin,R.S. Capps,G.W. Neifeld,J.P.o 1998 3/1998*Cryosurgery *Liver Neoplasms/di [Diagnosis] *Liver Neoplasms/su [Surgery] Carcinoma,Hepatocellular/di [Diagnosis] Carcinoma,Hepatocellular/su [Surgery] complications Cryosurgery Cryosurgery/ae [Adverse Effects] diagnosis Human Liver Liver Neoplasms/ra [Radiography] Liver Neoplasms/us [Ultrasonography] Magnetic Resonance Imaging Monitoring,Intraoperative Necrosis Postoperative Complications/di [Diagnosis] Recurrence surgery Tomography,X-Ray Computed Ultrasonography/is [Instrumentation] Ultrasonography/mt [Methods] United Statesg129-155e$Seminars in Surgical Oncology 142voBecause intraoperative sonography displays segmental anatomy, allows discovery of more lesions than previously suspected from preoperative imaging, surgical inspection, or palpation, and permits more certain diagnosis of problematic masses, it facilitates surgical decision-making when liver resection or cryoablation is anticipated. Intraoperative sonography provides a guidance modality to accurately place cryosurgery probes in liver masses. More precise treatment of metastatic and primary tumors of the liver is possible with cryoablation because intraoperative sonography provides a means of monitoring the growth of the enlarging freeze zone to insure adequate surgical margins. Postoperative detection of acute complications after cryosurgery is best done with computed tomography. Normally cryosurgery defects shrink with time and lose the peripheral contrast opacification seen after surgery. Gas collections, seen as a result of tissue necrosis, must be discriminated from infection. Tumor recurrence can be detected well with computed tomography or magnetic resonance imaging following hepatic cryosurgery. [References: 37]8DB - MEDLINE UI - 98153904 IN - Department of Radiology, Virginia Commonwealth University, Richmond 23298-0615, USA JC - sso, SSO, SSO, 8503713 Journal Subset Index Medicus CP - United States PT - Journal Article PT - Review PT - Review, Tutorial LG - English EM - 19980312 Revised: 20001218. Entry Week: 19980312 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 8756-0437BhbMultiphase helical CT findings after percutaneous ablation procedures for hepatocellular carcinoma2,Catalano,O. Esposito,M. Nunziata,A. Siani,A. 200011/2000a>8administration & dosage Adult Aged Carcinoma,Hepatocellular Catheter Ablation Contrast Media Ethanol Female Human Injections,Intralesional Laser Coagulation Liver Neoplasms Male methods Middle Age Necrosis Neoplasm,Residual Portal Vein radiography therapy Tomography,X-Ray Computed United States Pleural EffusionUI - 20483829 LA - eng RN - 0 (Contrast Media) RN - 64-17-5 (Ethanol) PT - Journal Article DA - 20001120 IS - 0942-8925 SB - IM CY - UNITED STATES JC - BMT RefMgr field[1]: Journal RefMgr field[8]: Not in File 607-6148 Abdom.Imaging256a BACKGROUND: Multiple-phase helical computed tomography (CT) has been regarded as the method of choice in the evaluation of patients with hepatocellular carcinoma (HCC) treated by nonsurgical procedures. The aim of this article was to report our experience in the assessment of nodular and parenchymal changes recognizable after various percutaneous ablation therapies. METHODS: We reviewed the studies of 116 consecutive patients with HCC treated with multisession percutaneous ethanol injection (56 patients, 98 nodules), single-session percutaneous ethanol injection (14 patients, 31 nodules), radiofrequency thermal ablation (32 patients, 48 nodules), and interstitial laser photocoagulation (14 patients, 25 nodules). CT had been performed 3-28 days after the last session (mean = 18 days) with unenhanced helical acquisition and with contrast-enhanced double- or triple-phase helical acquisition. RESULTS: Persisting neoplastic tissue was identified within 54.5% of the nodules. It was located centrally in 4.5% of these nodules, peripherally in 11%, and eccentrically in 84.5%, and its shape was crescent in 58%, globular in 24.5%, and other in 16%. On arterial phase scans, viable tumor was hyperdense in 97% of the lesions and isodense in 3%; on portal phase scans, the tumor was hyperdense in 20%, isodense in 28%, and hypodense in 52%; on delayed phase scans, the tumor was consistently hypodense. Tumor necrosis was always hypodense on contrast-enhanced scans. On unenhanced images, 7.4% of the nodules were undetectable. Nodule diameter appeared as unchanged in 53% of the nodules and as larger in 47%; its shape was unchanged in 54% and modified in 46%; its margins were unchanged in 36% and modified in 64%. A rim of granulation tissue was detected around 15% of the nodules, and a perilesional transient attenuation difference was detected in 21%. Perihepatic effusion was seen in 13% of the patients, segmental biliary duct dilation and local atrophy each in 9%, arterioportal fistula in 6%, portal vein thrombosis, subcapsular collection and pleural effusion each in 7%, hepatic infarction in 5%, and inferior vena cava thrombosis in 2%. CONCLUSION: Percutaneous ablation of HCC may cause several changes. Knowledge of their CT appearance is mandatory to correctly assess and manage this tumor'~xDepartment of Radiology, S. Maria delle Grazie Hospital, via Domitiana loc. La Schiana, Pozzuoli, Naples, I-80078, Italy142 PM:11029093  312zsGeneration and observation of radio frequency thermal lesion ablation for interventional magnetic resonance imaging& Chung,Y.C. Duerk,J.L. Lewin,J.S. 1997 8/1997*Catheter Ablation *Liver/pa [Pathology] *Liver/su [Surgery] *Magnetic Resonance Imaging/mt [Methods] Animal Cattle Electric Impedance Electrodes Liver Liver Neoplasms/di [Diagnosis] Liver Neoplasms/su [Surgery] Liver/pp [Physiopathology] Magnetic Resonance Imaging Magnetic Resonance Imaging/is [Instrumentation] methods Phantoms,Imaging Support,Non-U.S.Gov't Temperature therapy United States466-474iInvestigative Radiologyo328oRATIONALE AND OBJECTIVES: Recently, there has been increased interest in interventional magnetic resonance (MR) imaging and minimally invasive cancer therapy via radio frequency (RF) thermal ablation. In this work, we examined RF thermal lesion generation in phantoms and ex vivo bovine liver and correlated them with MR images under a variety of conditions, which begins our assessment of the role of MR imaging in this new method for cancer treatment. METHODS: Radio frequency lesions were created in gel phantoms and ex vivo bovine liver, using stationary (bovine liver) and variable speed (gel) moving electrodes to create lesions with shapes mimicking tumors. Ex vivo bovine liver lesions were made with the tissue held at room temperature (n = 4) and in a 37 degrees C saline bath (n = 3) using a 16-gauge electrode (tip temperature: 70 degrees C, 80 degrees C, and 90 degrees C; ablation time: 1-13 minutes). Electrical impedance and RF power were plotted during ablation. After ablation, RF-induced lesions were imaged with a 0.2-tesla (T) MR system using a variety of pulse sequences. RESULTS: Complex shaped lesions were created successfully in phantoms. Averaged maximum ex vivo lesion volume made at 90 degrees C ablation experiments holding the tissue temperature at 37 degrees C and at room temperature were 1.58 +/- 0.35 cm3 and 1.0 +/- 0.26 cm3 respectively (confidence interval: 90%). The aspect ratios and RF power of the lesions decreased as ablations proceeded. Impedance dropped during the first 2 minutes of the ablation. Ex vivo lesions appeared as regions of low-signal amplitude in T2-weighted MR images. CONCLUSIONS: Phantom ablation experience may be useful and applicable in thermotherapy planning. Lesions made in ex vivo bovine liver held at 37 degrees C via a saline bath are larger than those created at room temperature. Lesions shapes are ablation time dependent until thermal equilibrium is reached. Impedance reduction and lesion formation are related; 0.2-T MR systems can image RF energy-induced thermal lesionsf_DB - MEDLINE UI - 97403366 IN - Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA JC - gwk, GWK, GWK, 0045377 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 199710 Revised: 20001218. Entry Week: 199710 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0020-9996 398Magnetic resonance imaging of frozen tissues: temperature-dependent MR signal characteristics and relevance for MR monitoring of cryosurgery&Daniel,B.L. Butts,K. Block,W.F.e 1999 3/1999~w*Adipose Tissue/ah [Anatomy & Histology] *Freezing *Liver/ah [Anatomy & Histology] *Magnetic Resonance Imaging *Muscle,Skeletal/ah [Anatomy & Histology] Animal Cattle Cryosurgery Liver Magnetic Resonance Imaging Monitoring,Intraoperative/is [Instrumentation] Pilot Projects Reproducibility of Results Sensitivity and Specificity Temperature Tissue Culture United States Watery627-630o$Magnetic Resonance in Medicine413 Previously, the magnetic resonance (MR) imaging appearance of frozen tissues created during cryosurgery has been described as a signal void. In this work, very short echo times (1.2 msec) allowed MR signals from frozen tissues to be measured at temperatures down to -35 degrees C. Ex vivo bovine liver, muscle, adipose tissue, and water were imaged at steady-state temperatures from -78 degrees to +6 degrees C. Signal intensity, T2*, and T1 were measured using gradient-echo imaging. Signal intensity and T2* decrease monotonically with temperature. In the future, these MR parameters may be useful for mapping temperatures during cryosurgerysDB - MEDLINE UI - 99219583 IN - Department of Radiology, Lucas MRS/I Center, Stanford University, California 94305-5488, USA. bdaniel@s-word.stanford.edu JC - mhr, MHR, MHR, 8505245 Journal Subset Index Medicus CP - United States PT - Journal Article LG - English EM - 19990616 Revised: 20001218. Entry Week: 19990616 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0740-3194t < 408.piTemperature determination in the frozen region during cryosurgery of rabbit liver using MR image analysis-LEGilbert,J.C. Rubinsky,B. Wong,S.T. Brennan,K.M. Pease,G.R. Leung,P.P.o 1997 1997@:*Body Temperature/ph [Physiology] *Cryosurgery *Liver/ph [Physiology] *Magnetic Resonance Imaging/mt [Methods] analysis Animal Cryosurgery Female Freezing Image Processing,Computer-Assisted Liver Liver/su [Surgery] Magnetic Resonance Imaging Male Rabbits Support,U.S.Gov't,P.H.S. Temperature United States Prostate657-667c Magnetic Resonance Imaging156mD=Cryosurgery currently is being used clinically to treat tumors in internal organs such as the liver and prostate. Although performed at present under ultrasound monitoring, magnetic resonance imaging (MRI)-guidance of these procedures not only permits monitoring of the frozen region during cryosurgery but also makes it possible to determine the temperature distribution in the frozen region, which is not possible using ultrasound monitoring. A good estimate of the region of destruction in the tissue can be obtained from correlating the temperature distribution and the time course of the freezing with the image of the frozen region. Unfortunately, MR pulse sequence-based temperature determination techniques such as diffusion, relaxation time, and chemical shift cannot be used for measuring the temperature in the frozen region because the T2 of the frozen regions is so short that there is effectively no RF signal from the frozen region. This paper describes a numerical technique for determining the two dimensional temperature distribution in the frozen region during MR image-guided cryosurgery of normal liver in rabbits. The technique involves solving the energy equation numerically in the frozen region to determine the temperature distribution there. The boundary conditions needed to solve the equation are determined from MR images of the frozen tissue during cryosurgery and from the measured temperature of the cryoprobe. The calculated temperature in the frozen region is then correlated with the damaged region (cryolesion) determined from post mortem histologic evaluation DB - MEDLINE UI - 97431768 IN - Department of Radiology, University of California, San Fransisco 94143-1240, USA. gilbert@hurricane.ucsf.edu JC - mak, MAK, MAK, 8214883 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English NO - IR01 CA56898-01 (NCI) EM - 199710 Revised: 20001218. Entry Week: 199710 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0730-725X 533,~Radio-frequency-induced coagulation necrosis in rabbits: immediate detection at US with a synthetic microsphere contrast agentF@Goldberg,S.N. Walovitch,R.C. Straub,J.A. Shore,M.T. Gazelle,G.S. 199911/1999h*Adenocarcinoma/pa [Pathology] *Adenocarcinoma/us [Ultrasonography] *Contrast Media *Electrocoagulation *Liver Neoplasms/pa [Pathology] *Liver Neoplasms/us [Ultrasonography] *Microspheres *Necrosis 0 (Contrast Media) Adenocarcinoma Adenocarcinoma/su [Surgery] Animal Liver Neoplasms/su [Surgery] methods Necrosis Rabbits Radio Waves Support,Non-U.S.Gov't Temperature therapy United States438-444 Radiology 2132VX-2 rabbit model. Contrast agent enhancement in tumor pre-ablation. At ablation: hytperechoic foci within 1mm of histo in 7/12 animals. Post-ablation: foci devoid of enhancement within 1mm of histo in 11/12 animals. On US and histo 1 animal with an island of viable cells next to a 1mm vessel within lesion. Used two techniques to asses tumor viability at histo (2% Evans blue and 2,3,5-triphenyltetrazolium[mitochondrial activity marker])PURPOSE: To determine whether a synthetic ultrasonographic (US) contrast agent can be used to differentiate coagulation necrosis from untreated tumor immediately after radio-frequency ablative therapy. MATERIALS AND METHODS: VX2 (adenocarcinoma) tumors (0.8-1.5-cm diameter) were implanted into 12 rabbits. Gray-scale and color Doppler US were performed with or without intravenous injection of a US contrast agent composed of poly-lactide-co-glycolic acid polymeric (PLGA) microspheres (2-micron diameter) filled with perfluorocarbon gas. Radio frequency was applied to each nodule for 6 minutes at 127 mA +/- 33 (mean +/- SD) (tip temperature, 92 degrees C +/- 2). Repeat US with a second dose of the contrast agent was performed immediately after ablation. In four animals, a third dose was administered 30-120 minutes after ablation. Radiologic-histopathologic correlation was performed and included in vivo staining and studies of mitochondrial function. RESULTS: Intense contrast agent enhancement was seen throughout the tumor prior to ablation. At gray-scale US, ablation produced hyperechoic foci, which were within 1 mm of the foci identified at histopathologic examination in seven of 12 animals (58%). After the administration of contrast material, foci devoid of previously visualized enhancement, which measured 7.3-15.0 mm, were identified. These were within 1 mm of the size of the foci identified at histopathologic examination in 11 of 12 animals (92%, P < .01). In two animals, enhancement depicted viable tumor, which appeared hyperechoic, on nonenhanced images. On delayed images, hyperechoic areas decreased in size, whereas the nonenhanced region remained unchanged. CONCLUSION: A PLGA microspherical US contrast agent enabled the immediate detection of coagulation necrosis as a region devoid of contrast enhancement after radio-frequency ablation in rabbit hepatic tumors. Therefore, this agent could provide real-time guidance during complex ablative procedures and may provide an efficient technique for postprocedural assessmentyDB - MEDLINE UI - 20018921 IN - Department of Radiology, Massachusetts General Hospital, Boston, USA. sgoldber@caregroup.harvard.edu JC - qsh, QSH, QSH, 0401260 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 19991207 Revised: 20001218. Entry Week: 19991207 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0033-8419lete thawing, the cryolesion became less echogenic than before freezing and was therefore distinguishable under ultrasound. Postsurgical pathologic examination showed excellent correlation between the lesion size and its ultrasonic imageo DB - MEDLINE UI - 85283948 JC - dt3, DT3, DT3, 0006252 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 198510 Revised: 20001218. Entry Week: 198510 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0011-2240e X x Farina, Dino 19980*Building a Low-Cost Thermal Imaging SystemSensors 12-16 July 1998 271.>7Ultrasound imaging of thermal therapy in in vitro liver<5Gertner,M.R. Worthington,A.E. Wilson,B.C. Sherar,M.D.e 1998 9/1998*Hyperthermia,Induced *Liver/us [Ultrasonography] Animal Biophysics Body Temperature Cattle Comparative Study Feasibility Studies In Vitro Liver Microwaves/tu [Therapeutic Use] Monitoring,Physiologic/mt [Methods] Support,Non-U.S.Gov't Temperature therapy 1023-1032h& Ultrasound in Medicine & Biology2473The objective of this work was to image liver tissue heated to temperatures below the vaporization threshold as a function of time, to test the feasibility of real-time ultrasound monitoring to control lesion size during minimally invasive thermal therapy (MITT). Two experiments were devised. In one experiment, a thermal gradient was established in a rectangular volume of tissue to correlate changes in ultrasound image echogenicity (B-mode image brightness) with tissue temperature. In the other, a thermal lesion was produced in a rectangular volume of tissue by an interstitial microwave antenna, and the progression of the lesion was monitored by ultrasound. In both experiments, the echogenicity of the tissue increased slightly for tissue temperatures up to 40 degrees C, but became lower than that of unheated tissue for temperatures above 40 degrees C. In the second experiment, images of the lesion were compared with a photograph of the lesion taken after the experiment was complete. The final lesion was composed of two concentric regions--an inner region of heavily coagulated tissue and an outer region of less-damaged tissue. These two damaged regions indicated that increased ultrasound attenuation was largely responsible for the decreased echogenicity observed in the ultrasound images, and the increase in echogenicity of tissue heated to temperatures up to 40 degrees C is thought to be due to decreased ultrasound attenuation at these temperatures:rlDB - MEDLINE UI - 99025508 IN - Department of Medical Biophysics, University of Toronto and Ontario Cancer Institute, Canada JC - wne, WNE, WNE, 0410553 Journal Subset Index Medicus CP - England PT - Journal Article LG - English EM - 19990113 Revised: 20001218. Entry Week: 19990113 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0301-5629 436.<6Real time ultrasonic monitoring of hepatic cryosurgery6/Gilbert,J.C. Onik,G.M. Hoddick,W.K. Rubinsky,B.] 1985 8/1985*Cryosurgery *Hepatectomy/mt [Methods] *Ultrasonography Animal Cryosurgery Dogs Freezing Liver Liver Neoplasms/su [Surgery] Liver/pa [Pathology] Male Monitoring,Physiologic Support,Non-U.S.Gov't Ultrasonography United States319-330  Cryobiology 224rCryosurgery has a number of advantages that make it particularly appealing in the treatment of liver cancer. However, a major problem in the clinical application of hepatic cryosurgery is the lack of a precise means of monitoring the freezing process in situ. Preliminary investigations on simulated tissue have shown that standard ultrasonography is capable of accurately determining the amount of frozen material during a cryosurgical procedure. To extend these results to living tissue, cryosurgery was performed, in vivo, on the livers of four mongrel dogs. An ultrasound imaging device using a new intraoperative ultrasound transducer monitored the entire process in real time. The results indicate that the entire freezing and thawing cycle can be monitored easily using real time ultrasound. During freezing, the solidification interface can be seen to move through the tissue allowing clear imaging of the cryolesion. After complete thawing, the cryolesion became less echogenic than before freezing and was therefore distinguishable under ultrasound. Postsurgical pathologic examination showed excellent correlation between the lesion size and its ultrasonic imageo DB - MEDLINE UI - 85283948 JC - dt3, DT3, DT3, 0006252 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 198510 Revised: 20001218. Entry Week: 198510 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0011-2240e  V & 544,D>Intraoperative and laparoscopic ultrasound. [Review] [84 refs]Kolecki,R. Schirmer,B. 1998 4/1998*Digestive System Neoplasms/us [Ultrasonography] *Laparoscopy Biliary Tract Neoplasms/us [Ultrasonography] Colorectal Neoplasms/us [Ultrasonography] Esophageal Neoplasms/us [Ultrasonography] Gastrointestinal Neoplasms/us [Ultrasonography] Human Intraoperative Period Laparoscopy Liver Liver Neoplasms/us [Ultrasonography] Pancreatic Neoplasms/us [Ultrasonography] Stomach Neoplasms/us [Ultrasonography] surgery therapy United States251-271(!Surgical Clinics of North America782Review. Pre-operative determinations of resectability based on CT or MRI only accurate from 60-80%. In patients undergoing resection IOUS has been shown to change operative plan 38 to 49% of casesPIIntraoperative ultrasound, whether during celiotomy or laparoscopy, plays an important role in assisting the surgeon in directing appropriate therapy for intra-abdominal diseases, particularly primary or metastatic malignancies involving the liver and primary malignancies of the pancreas and upper gastrointestinal tract. It is the most sensitive imaging technique for detecting small intraparenchymal lesions of the liver, pancreas, and other solid organs. Owing to its increased sensitivity over all commonly used preoperative imaging studies, it is responsible for changing the intraoperative treatment plan of these tumors in a significant percentage of cases. This is particularly true with respect to resectability. In the era of laparoscopic surgery, it replaces the surgeon's inability to palpate the liver and other organs during surgery. As surgeons use a laparoscopic approach with increasing frequency to treat intra-abdominal disease, they will have an increasing need to master the use of intraoperative ultrasound in order to render optimal care to their patients. [References: 84]mDB - MEDLINE UI - 98265556 IN - Department of Surgery, University of Virginia Health Sciences Center, Charlottesville, USA JC - van, 0074243 Journal Subset AIM Journals CP - United States PT - Journal Article PT - Review PT - Review, Tutorial LG - English EM - 19980610 Revised: 20001218. Entry Week: 19980610 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0039-6109t 346B;Hepatic tumors treated by cryosurgery: normal CT appearance9^WKuszyk,B.S. Choti,M.A. Urban,B.A. Chambers,T.P. Bluemke,D.A. Sitzmann,J.V. Fishman,E.K.. 1996 2/1996*Cryosurgery *Liver Neoplasms/ra [Radiography] *Liver Neoplasms/su [Surgery] *Postoperative Complications/ra [Radiography] analysis complications Cryosurgery Diagnosis,Differential Female Hemorrhage Human Infarction/ra [Radiography] Liver Liver Abscess/ra [Radiography] Liver Neoplasms/sc [Secondary] Liver/bs [Blood Supply] Liver/su [Surgery] Lung Male methods Middle Age Support,U.S.Gov't,P.H.S. Tomography,X-Ray Computed United States Air Pleural Effusion363-368h,%AJR.American Journal of Roentgenology  166 2mOBJECTIVE: An understanding of the normal appearance of hepatic tumors treated with cryosurgery is essential for accurately distinguishing normal postoperative changes from potential complications such as hepatic abscess or infarct, which may necessitate further interventions. The purpose of this study was to characterize the normal spectrum of CT findings after cryoablation of hepatic tumors. SUBJECTS AND METHODS: The CT scans of 14 patients who had undergone hepatic cryoablation 4-16 days (mean, 7 days) before scanning were reviewed by three radiologists. None of these patients had postprocedural complications that necessitated intervention (e.g. abscess, infarct, or hemorrhage). Indications for cryoablation included primary hepatic tumors in four patients and hepatic metastases in 10 patients. CT findings were correlated with surgical findings in a lesion-by-lesion manner to ensure that only cryolesions were included in the analysis. RESULTS: Twenty-eight cryolesions from 3 to 11 cm maximum diameter (mean, 7 cm) were detected on CT scans. All cryolesions were primarily hypodense and extended to the liver capsule. Ten (36%) of 28 lesions contained air, and 26 (93%) of 28 lesions contained hemorrhage. Thirteen (54%) of 24 lesions evaluated with i.v. contrast material showed peripheral enhancement. Cryolesions were primarily wedge shaped (54%), round (29%), or teardrop shaped (21%). One iatrogenic portosystemic shunt was detected. Other associated findings included subcapsular hemorrhage (29%), perihepatic fluid collections (43%), right-sided pleural effusion (93%), left-sided pleural effusion (64%), atelectasis of one or both lungs (93%), and ascites (7%). CONCLUSION: The postoperative CT appearance of the liver in patients who underwent hepatic cryoablation without complications mimics that seen in the liver of patients with hepatic abscesses or infarcts. The CT appearance of the liver in patients undergoing cryosurgery needs to be carefully analyzed to avoid confusing normal findings related to the procedure with those related to procedural complications, it may be impossible to differentiate hepatic complications from normal postoperative changes on the basis of CT findings in many of these patientsDB - MEDLINE UI - 96143111 IN - Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA JC - 3ae, 3AE, 3AE, 7708173 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English NO - CA 55641-01A1 (NCI) EM - 199602 Revised: 20001218. Entry Week: 199602 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0361-803X45voLocal tumor recurrence following hepatic cryoablation: radiologic-histopathologic correlation in a rabbit modelleKuszyk,B.S. Boitnott,J.K. Choti,M.A. Bluemke,D.A. Sheth,S. Magee,C.A. Horton,K.M. Eng,J. Fishman,E.K.p 200011/2000[*Cryosurgery *Liver Neoplasms,Experimental/su [Surgery] *Liver/su [Surgery] *Neoplasm Recurrence,Local Animal Liver Liver Neoplasms,Experimental/di [Diagnosis] Liver Neoplasms,Experimental/pa [Pathology] Liver Neoplasms,Experimental/ra [Radiography] Liver/pa [Pathology] Liver/ra [Radiography] Liver/us [Ultrasonography] Magnetic Resonance Imaging Male methods Necrosis Rabbits Recurrence Support,Non-U.S.Gov't Tomography,X-Ray Computed Ultrasonography Ultrasonography,Doppler,Color United States477-486r Radiologye 217H2f6/PURPOSE: To use radiologic-histopathologic correlation in an animal model to distinguish normal postoperative findings from evidence of residual tumor after cryoablation of malignant hepatic tumors. MATERIALS AND METHODS: Hepatic cryoablation was performed in 12 rabbits with VX2 tumors and in two healthy rabbits. Nonenhanced and dynamic contrast material-enhanced computed tomography (CT) and magnetic resonance (MR) imaging and power and color Doppler flow ultrasonography (US) were performed 7-8 days after cryoablation. Histopathologic findings were correlated with imaging findings. RESULTS: Twenty tumors of 5-20 mm (mean, 10 mm) and seven areas of normal liver were treated with cryolesions of 11-21 mm (mean, 15 mm). All cryolesions exhibited arterial phase rim enhancement at CT and MR imaging, and 13 (57%) of 23 lesions demonstrated peripheral flow at US because of granulation tissue. There was macroscopic recurrence in 15 (75%) of 20 treated tumors; 14 (93%) appeared as peripheral nodularity with low-grade enhancement. Necrotic tissue did not enhance. Intact vessels extended up to 6 mm inside cryolesion margins and caused focal internal enhancement and Doppler flow. Areas of high signal intensity on T2-weighted MR images correlated with liquefaction necrosis, granulation tissue, and tumor. CONCLUSION: In this animal model, recurrent tumor typically appeared as focal nodules at the cryolesion periphery. Rim and central foci of enhancement, Doppler flow, and increased signal intensity on T2-weighted MR images can be normal findings after hepatic cryoablationaDB - MEDLINE UI - 20514485 IN - Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimorem MD 21287, USA JC - qsh, QSH, QSH, 0401260 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 20001121. Entry Week: 20001121 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0033-8419h  (~Follow-Up Studies Forecasting FreezingGadolinium DTPAon4/Gastrointestinal Neoplasms/us [Ultrasonography]Glass$!Granulation Tissue/pa [Pathology]Heat Hemorrhage HepatectomyHepatectomy/*methodsHepatic ArteryHuman HyperemiaIce("Image Processing,Computer-Assisted In Vitro Infarction/ra [Radiography] InjectionsInjections,IntralesionalinstrumentationonIntraoperative Care Intraoperative Care/*methodsIntraoperative Period LaparoscopyLaser CoagulationLiver$Liver Abscess/ra [Radiography]Liver DiseasesLiver Neoplasmson0+Liver Neoplasms,Experimental/di [Diagnosis]0+Liver Neoplasms,Experimental/pa [Pathology]0-Liver Neoplasms,Experimental/ra [Radiography]4/Liver Neoplasms/*radiography/*secondary/surgery$Liver Neoplasms/di [Diagnosis] [M$Liver Neoplasms/mo [Mortality]$Liver Neoplasms/pa [Pathology] [M83Liver Neoplasms/pathology/*surgery/*ultrasonography$ Liver Neoplasms/ra [Radiography]g84Liver Neoplasms/radiography/*surgery/ultrasonography$Liver Neoplasms/sc [Secondary] [M Liver Neoplasms/su [Surgery]s Liver Neoplasms/th [Therapy]($Liver Neoplasms/us [Ultrasonography]]0+Liver/*radiography/surgery/*ultrasonographyLiver/bs [Blood Supply]Liver/pa [Pathology]S Liver/pp [Physiopathology]y]sLiver/ra [Radiography]Liver/su [Surgery]Com Liver/us [Ultrasonography]Lung Magnetic Resonance Imaginging(%Magnetic Resonance Imaging/*standards4/Magnetic Resonance Imaging/is [Instrumentation]PrMaler methodsap$Microwaves/tu [Therapeutic Use] Middle AgePat($Monitoring, Intraoperative/standardsMonitoring,Intraoperative4.Monitoring,Intraoperative/is [Instrumentation],&Monitoring,Intraoperative/mt [Methods]Monitoring,Physiologic0+Monitoring,Physiologic/is [Instrumentation](#Monitoring,Physiologic/mt [Methods]$Muscle,Skeletal/pa [Pathology] Necrosisn(#Neoplasm Staging/*methods/standardsNeoplasm, ResidualNeoplasm,Residual Nitrogen,)Pancreatic Neoplasms/us [Ultrasonography] pathology PerfusionPhantoms,ImagingcPilot ProjectsraoPleural Effusion  Portal Veinsi0*Postoperative Complications/di [Diagnosis]82Postoperative Hemorrhage/pc [Prevention & Control]($Preoperative Care/*methods/standards Prognosis Proportional Hazards ModelsProspective Studies Prostate Rabbitsc  Radio Waves$Radiographic Image Enhancement radiographysiRadiology,Interventionaln Recurrenceive Reproducibility of Resultsis Retrospective Studies Safety secondary Sensitivity and Specificitys SilicatesSingle-Blind Method,&Stomach Neoplasms/us [Ultrasonography]Support, Non-U.S. Gov'tSupport,Non-U.S.Gov'tSupport,U.S.Gov't,P.H.S.Surface Properties surgeryAgSurvival AnalysisSwine Temperature-U therapyapThrombosis/pa [Pathology] Time FactorsTissue Cultured S Tomography, X-Ray Computed(%Tomography, X-Ray Computed/*standardsTomography,X-Ray ComputedTreatment OutcomeUltrasonographyUltrasonography, DopplerUltrasonography,Doppler Ultrasonography,Doppler,Color$Ultrasonography,Interventional($Ultrasonography/is [Instrumentation]n Ultrasonography/mt [Methods]nUltrasonography/standards United StatesWater &surgery43piEchogenicity of liver metastases is an independent prognostic factor after potentially curative treatment->7Gruenberger,T. Jourdan,J.L. Zhao,J. King,J. Morris,D.L. 200011/2000 *Liver Neoplasms/sc [Secondary] *Liver Neoplasms/us [Ultrasonography] analysis Colorectal Neoplasms/pa [Pathology] Cryotherapy Female Hepatectomy Hepatic Artery Human Intraoperative Care Liver Liver Neoplasms/mo [Mortality] Liver Neoplasms/su [Surgery] Male Middle Age Prognosis Proportional Hazards Models Prospective Studies Retrospective Studies secondary surgery Survival Analysis Treatment Outcome United States 1285-1290Archives of Surgery 13511HYPOTHESIS: Intraoperative echogenic appearance of liver metastases from colorectal cancer is a prognostic factor of outcome after curative treatment. DESIGN: Retrospective analysis of prospectively collected data. SETTING: Department of Surgery at a university hospital. PATIENTS: One hundred forty-three consecutive patients with hepatic metastases from colorectal cancer who underwent liver resection with curative intent between 1992 and 1998. INTERVENTION: Curative treatment was achieved by liver resection alone, liver resection plus edge cryotherapy, or liver resection plus cryotherapy to lesions not amenable to further resection. In patients with more than 2 lesions, a hepatic artery catheter was placed for regional chemotherapy. MAIN OUTCOME MEASURES: The echogenic appearance of the liver metastases was assessed by intraoperative ultrasound by a single person throughout the study using a 5-MHz ultrasound probe. The findings were prospectively entered into the database. RESULTS: Fifty-four percent of patients had hyperechoic metastases. This group had significantly longer overall (log rank, P<.001) and recurrence-free survival (log rank, P =.004) compared with patients who had hypoechoic metastases (36%). A significantly higher percentage of mucin-secreting tumors were found in the hypoechoic patient group (chi(2), P =.001). Dukes stage of the primary tumor (P =.02), echogenicity of the liver secondaries (P =.04), and diameter of the largest resected metastasis (P =.01) were independent prognostic factors for recurrence-free survival in the Cox regression model. CONCLUSION: These results support the hypothesis that echogenicity of liver metastases from colorectal cancer is an independent prognostic factor of outcome after curative resection8yDB - MEDLINE UI - 20529145 IN - UNSW, Department of Surgery, St George Hospital, Pitney Clinical Science Building, Level 3, Kogarah, Sydney, NSW 2217, Australia JC - 8ia, 9716528 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 20001206. Entry Week: 20001206 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0004-0010  ZTThe role of contrast-enhanced sonography for radiofrequency ablation of liver tumorsNGLiu,J.B. Goldberg,B.B. Merton,D.A. Rawool,N.M. Needleman,L. Forsberg,F.A 2001 5/20012+Liver methods Rabbits therapy United StatesUI - 21241362 LA - eng PT - Journal Article DA - 20010509 IS - 0278-4297 SB - IM CY - United States JC - KBU RefMgr field[1]: Journal RefMgr field[8]: Not in File517-523J.Ultrasound Med.205^XOBJECTIVE: To assess the feasibility and usefulness of contrast- enhanced sonography for tumor detection and guidance of liver VX2 tumor ablation and to evaluate post radiofrequency ablation effectiveness. METHODS: VX2 tumors were implanted into the livers of 6 rabbits. Both conventional and harmonic gray scale and power Doppler imaging were performed with a commercially available scanner to evaluate the liver tumors before and after intravenous injection of a sonographic contrast agent before and after radiofrequency ablation. Contrast-enhanced imaging was used to detect the tumors before ablation, to guide needle insertion, and to measure the ablation sites after radiofrequency ablation. Pathologic examination was performed for comparison. RESULTS: Three tumors were seen without contrast enhancement, whereas 10 tumors (<1 cm) were detected with contrast enhancement. Intentionally, 2 tumors were completely ablated and 5 tumors were partially ablated. In 3 cases, incompletely ablated tumors could only be identified on contrast-enhanced Doppler imaging by enhancing the detection of residual tumor vascularity. There was excellent concordance between sonographic imaging and gross pathologic findings. CONCLUSIONS: Contrast-enhanced sonographic imaging appears useful for detection of liver tumors and for guiding and monitoring tumor ablation therapies'jdDepartment of Radiology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania 19107, USA173 PM:11345109 360PICT of the liver after cryotherapy of hepatic metastases: imaging findingsvD=McLoughlin,R.F. Saliken,J.F. McKinnon,G. Wiseman,D. Temple,W.s 1995 8/1995@:*Cryotherapy *Liver Neoplasms/ra [Radiography] *Liver Neoplasms/sc [Secondary] *Liver/ra [Radiography] *Tomography,X-Ray Computed Aged blood complications Cryotherapy diagnosis Diagnosis,Differential Female Follow-Up Studies Human Liver Liver Neoplasms/th [Therapy] Male Middle Age Safety Temperature United States329-332 ,%AJR.American Journal of Roentgenologyh 165d2 F?Cryotherapy is the in situ destruction of abnormal tissue using subzero temperatures (Fig. 1). Recent studies have demonstrated the technical feasibility, safety, and effectiveness of hepatic cryotherapy in the treatment of liver tumors and 2 over black square];.[1 and 2 over black square], 2]. Such treatment can be precisely focused on the tumor, thereby preserving surrounding normal tissue. In addition, because major vessels with flowing blood are protected from cryoablation, tumors adjacent to these vessels can be treated without sacrificing vasculature. Hepatic cryoablation is therefore particularly suitable for patients who do not qualify for surgical resection because of multiple metastases involving both lobes of the liver, or because of lesions close to major blood vessels. After the procedure, CT during arterioportography is of little value in distinguishing cryolesion from malignant tumor (Fig. 2), and CT with IV contrast enhancement is recommended for follow-up. It is important to distinguish CT findings of successful and unsuccessful treatment, treatment complications such as abscess and cholestasis, and recurrent tumor. The purpose of this essay is to illustrate the findings on CT with IV contrast enhancement in various situations, emphasizing features that are useful in making accurate differential diagnosisyDB - MEDLINE UI - 95343841 IN - Department of Radiological Sciences and Diagnostic Imaging, Foothills Hospital, Calgary, Alberta, Canada JC - 3ae, 3AE, 3AE, 7708173 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 199508 Revised: 20001218. Entry Week: 199508 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0361-803X 392aComparison of iceball diameter and temperature distribution achieved with 3-mm accuprobe cryoprobes in porcine and human liver tissue and human colorectal liver metastases in vitroNGPopken,F. Seifert,J.K. Engelmann,R. Dutkowski,P. Nassir,F. Junginger,T.d 2000 6/2000"*Cryosurgery/is [Instrumentation] *Liver Neoplasms/sc [Secondary] *Liver Neoplasms/su [Surgery] *Liver/su [Surgery] Animal Colorectal Neoplasms Comparative Study Cryosurgery/mt [Methods] Evaluation Studies Human Ice In Vitro Liver Support,Non-U.S.Gov't Swine Temperature United States302-310 Cryobiology404We aimed to assess the thermal profile and size of iceballs produced by Accuprobe cryoprobes in fresh porcine and human liver and human colorectal cancer liver metastases in vitro to allow better planning of cryosurgical treatment of liver metastases. Iceballs were produced by a 20-min single freeze cycle using 8-mm cryoprobes in pig liver in a waterbath at 37 degrees C (n = 8) and 3-mm cryoprobes in pig liver (n = 8), human liver (n = 3), and human colorectal cancer liver metastases (n = 8). The iceball diameters and the temperatures at different distances from the cryoprobe were measured. Mean iceball diameters produced by 8-mm cryoprobes in pig liver were 56.3 mm and varied from 38.7 to 39.6 mm for 3-mm cryoprobes in the different tissues used. There was no significant difference in iceball size in the different tissues. The diameter of the zone of -40 degrees C or less was approximately 44 mm using 8-mm cryoprobes in porcine liver and between 27 and 31 mm using 3-mm cryoprobes in the different tissues examined. The results may allow better preoperative planning of the cryosurgical treatment of liver metastases with Accuprobe cryoprobes. Copyright 2000 Academic PressDB - MEDLINE UI - 20384493 IN - Klinik fur Allgemein- und Abdominalchirurgie, der Johannes Gutenberg-Universitat, Langenbeckstr, 1, Mainz, 55101, Germany JC - dt3, DT3, DT3, 0006252 Journal Subset Index Medicus CP - United States PT - Journal Article LG - English EM - 20001006 Revised: 20001218. Entry Week: 20001006 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0011-2240  11287540124u 2001 Apr\\UValue of three-dimensional US for optimizing guidance for ablating focal liver tumors 507-15 PURPOSE: To determine if three-dimensional ultrasound (3D US), by nature of its ability to simultaneously evaluate structures in three orthogonal planes and to study relationships of devices to tumor(s) and surrounding anatomic structures from any desired orientation, adds significant additional information to real-time 2D US used for placement of devices for ablation of focal liver tumors. MATERIALS AND METHODS: Sixteen patients underwent focal ablation of 23 liver tumors during two intraoperative cryoablation (CA) procedures, three intraoperative radiofrequency ablation (RFA) procedures, 11 percutaneous ethanol injections (PEI) procedures, and six percutaneous RFA procedures. After satisfactory placement of the ablative device(s) with 2D US guidance, 3D US was used to reevaluate adequacy to device position. Information added by 3D US and resultant alterations in device deployment were tabulated. RESULTS: 3D US added information in 20 of 22 (91%) procedures and caused the operator to readjust the number or position of ablative devices in 10 of 22 (45%) of procedures. Specifically, 3D US improved visualization and confident localization of devices in 13 of 22 (59%) procedures, detected unacceptable device placement in 10 of 22 (45%), and determined that 2D US had incorrectly predicted device orientation to a tumor in three of 22 (14%). CONCLUSIONS: Compared to conventional 2D US, 3D US provides additional relationship information for improved placement and optimal distribution of ablative agents for treatment of focal liver malignancy.'Department of Radiology, University of California Medical Center, 200 West Arbor Drive, San Diego, CA 92103, USA. scrose@ucsd.eduRose, S. C. Hassanein, T. I. Easter, D. W. Gamagami, R. A. Bouvet, M. Pretorius, D. H. Nelson, T. R. Kinney, T. B. James, G. M. 1051-0443 Journal ArticleJ Vasc Interv RadiolAdult Aged Carcinoma, Hepatocellular/pathology/*surgery/*ultrasonography Catheter Ablation/*methods Cryosurgery Female Human *Imaging, Three-Dimensional Liver Neoplasms/pathology/*surgery/*ultrasonography Male Middle Age Treatment Outcome *Ultrasonography, Interventionalhttp://www.jvir.org/cgi/content/full/12/4/507 http://www.jvir.org/cgi/content/abstract/12/4/507 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11287540 549jdPhase imaging on a .2-T MR scanner: application to temperature monitoring during ablation procedures,%Sinha,S. Oshiro,T. Sinha,U. Lufkin,R. 1997 9/1997rl*Catheter Ablation *Echo-Planar Imaging/is [Instrumentation] *Echo-Planar Imaging/mt [Methods] *Image Enhancement/mt [Methods] *Temperature Animal Calibration Cattle Human In Vitro Liver Liver/su [Surgery] methods Monitoring,Physiologic/is [Instrumentation] Monitoring,Physiologic/mt [Methods] Phantoms,Imaging Sensitivity and Specificity Temperature United States918-928,%Journal of Magnetic Resonance Imaging75haGel and ex vivo calf liver. Temp monitoring of RFA with MR. Specially developed copper electrodetmProton phase shift imaging methods with keyholing were developed to rapidly monitor temperature during MR-guided radiofrequency (RF) interventional procedures on a .2-T open configuration scanner. Temperature calibration was performed on thermally controlled gel phantom and ex vivo bovine liver samples. Keyholing methods were implemented for rapid imaging and tested both in simulation experiments and in the gel phantom. Phase drifts from extraneous sources were monitored and compensated for using reference phantoms. Sequence parameters TE, TR, and flip angle (FA) were optimized for maximum temperature sensitivity and minimum noise. Reduction of phase noise from coupling of the magnetic field to external perturbations using navigator-echo-based correction schemes were also investigated. The extraneous phase drifts from the magnet could be minimized by keeping the electromagnet on continuously. Navigator echo corrected keyholed FLASH sequences (TE = 30 msec, TR = 60 msec, FA = 40 degrees, 64 x 128 matrix) were used to monitor the RF lesioning process in gel phantoms yielding images every 4 seconds with a temperature sensitivity of .015 ppm/degree C. RF ablation in the bovine tissue was monitored using navigator-echo-corrected keyholed fast low angle shot (FLASH) sequences (TE = 30 msec, TR = 100 msec, FA = 40 degrees, 128 x 256 matrix) with a temporal resolution of 13 seconds and a temperature sensitivity of .007 ppm/degree C. The results indicate that monitoring of an RF ablation procedure by mapping temperature with sufficient temporal resolution is possible using phase images of FLASH sequences on a .2-T open scannerzsDB - MEDLINE UI - 97453177 IN - Department of Radiological Sciences, UCLA School of Medicine 90024, USA. s-sinha@mail.rad.ucla.edu JC - beo, BEO, BEO, 9105850 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 199801 Revised: 20001218. Entry Week: 199801 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 1053-1807 X 301Radio-frequency-induced thermoablation: monitoring with T1-weighted and proton-frequency-shift MR imaging in an interventional 0.5-T environmentNGSteiner,P. Botnar,R. Dubno,B. Zimmermann,G.G. Gazelle,G.S. Debatin,J.F.n 1998 3/1998*Catheter Ablation/mt [Methods] *Liver/su [Surgery] *Magnetic Resonance Imaging/mt [Methods] *Muscle,Skeletal/su [Surgery] Animal Evaluation Studies Feasibility Studies Liver Liver/pa [Pathology] Magnetic Resonance Imaging/is [Instrumentation] methods Monitoring,Intraoperative/is [Instrumentation] Monitoring,Intraoperative/mt [Methods] Muscle,Skeletal/pa [Pathology] Radiology,Interventional Support,Non-U.S.Gov't Swine Temperature United States803-810 Radiology 2063PURPOSE: To evaluate the feasibility and accuracy of monitoring radio-frequency (RF) ablation with an open-configuration, 0.5-T magnetic resonance (MR) imager. MATERIALS AND METHODS: Thirty-six in vivo RF ablation experiments were performed in porcine paravertebral muscle (n = 24) and liver (n = 12). A 90 degrees C tip temperature was applied for 3-9 minutes. MR images were acquired after continuous or during intermittent RF application. Temperature changes were monitored as signal intensity and proton-frequency-shift (PFS) alterations in two T1-weighted gradient-echo sequences. An update image was obtained every 2.5 seconds (20/10 [repetition time msec/echo time [TE] msec]) or every 5.0 seconds (40/20). A color-coded subtraction technique enhanced the signal intensity and PFS changes. Macroscopic coagulation size was compared with MR image lesion size. RESULTS: The RF application mode had no significant effect on coagulation size in muscle or liver (P > .05). Twenty-two of 24 coagulative lesions in muscle and nine of 12 in liver were demonstrated with the PFS technique. Accuracy of lesion size determination depended on TE (TE = 20 msec, r = .95; TE = 10 msec, r = .78 [P < .01]). The T1-weighted technique depicted only six of 24 muscle and three of 12 liver lesion ablations. In the lesions depicted, macroscopic size was significantly underestimated (P < .001). CONCLUSION: PFS MR monitoring of RF effects in liver and muscle is feasible and accurate. The PFS technique outperformed the T1-weighted technique\VDB - MEDLINE UI - 98155609 IN - Department of Radiology, University Hospital, Zurich, Switzerland JC - qsh, QSH, QSH, 0401260 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 19980326 Revised: 20001218. Entry Week: 19980326 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0033-8419 <:3Andreuccetti, D Bini, M Ignesti, A Olmi, R Vanni, R3 1991PIPhantom characterization of applicators by liquid-crystal-plate dosimetrylInt J Hyperthermia7{1l175-183A method for the determination of the SAR distribution produced by an electromagnetic applicator for localized hyperthermia is described. The procedure for SAR evaluation consists of recording the time evolution of the temperature inside a polyacrylamide phantom by means of thermochromic liquid crystal sheets inserted in it. The technique allows a complete characterization of applicators in a very broad frequency range, using power levels of the order of those needed in real treatments. Criteria for the minimum phantom size and the maximum time duration of the characterization procedure are indicated, which allow a reliable determination of the effective field size and penetration depth of the applicator. [Journal Article; In English; England] TY - JOURhahttp://www.sciencedirect.com/science/article/B6WVB-43G4DGK-3NF/1/9e92aca9690dd69756a10a1a285e88f5tated (P < .001). CONCLUSION: PFS MR monitoring of RF effects in liver and muscle is feasible and accurate. The PFS technique outperformed the T1-weighted technique\VDB - MEDLINE UI - 98155609 IN - Department of Radiology, University Hospital, Zurich, Switzerland JC - qsh, QSH, QSH, 0401260 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 19980326 Revised: 20001218. Entry Week: 19980326 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0033-8419  ~ 297^WMR-guided interstitial cryotherapy of the liver with a novel, nitrogen-cooled cryoprobe.~wTacke,J. Adam,G. Speetzen,R. Brucksch,K. Bucker,A. Heshel,I. Prescher,A. van Vaals,J.J. Hunter,D.W. Rau,G. Gunther,R.W.1 1998 3/1998*Cryosurgery/is [Instrumentation] *Liver/su [Surgery] *Magnetic Resonance Imaging *Radiology,Interventional 0 (Boron Compounds) 0 (Contrast Media) 0 (Glass) 0 (Silicates) 7727-37-9 (Nitrogen) Animal Artifacts Bile Ducts,Intrahepatic/pa [Pathology] Blood Loss,Surgical/pc [Prevention & Control] Blood Vessels/pa [Pathology] Boron Compounds complications Contrast Media Cryosurgery/mt [Methods] Cryotherapy Disease Models,Animal Equipment Design Female Follow-Up Studies Forecasting Freezing Glass Granulation Tissue/pa [Pathology] Liver Liver/bs [Blood Supply] Liver/pa [Pathology] Monitoring,Intraoperative Necrosis Nitrogen Postoperative Hemorrhage/pc [Prevention & Control] Rabbits Silicates Surface Properties Thrombosis/pa [Pathology] United States354-360$Magnetic Resonance in Medicine393The purpose of the study was to test a newly developed, MR-compatible, liquid nitrogen-cooled cryoprobe. The probe has an outer diameter of 3.5 mm and was specifically developed for percutaneous, MR-guided, interstitial cryotherapy. The probe was inserted percutaneously into the livers of 10 rabbits. The cryotherapy procedure was monitored with a surface coil in a 1.5 Tesla magnet using a gradient echo sequence. Follow-up examinations were performed 3 and 7 days after the freezing procedure using T1- and T2-weighted spin echo sequences. At 7 days the animals were sacrificed and the cryolesions were examined histologically. The cryoprobe enabled artifact-free MR imaging of the "iceball" formation during freezing of the rabbit liver. After 1 min of freezing, the iceball at the tip of the probe showed an average maximum diameter of 10.8 mm. No bleeding complications were observed during or after the freezing procedure. Histologic examination 7 days after cryotherapy confirmed that the liver lesions were the same size as had been predicted by the images of the acute iceball. This new, percutaneously inserted, MR-compatible, liquid-nitrogen cooled cryoprobe allows accurate, artifact-free MR imaging of interstitial cryotherapyjcDB - MEDLINE UI - 98158355 IN - Department of Diagnostic Radiology, University of Technology, Aachen, Germany JC - mhr, MHR, MHR, 8505245 Journal Subset Index Medicus CP - United States PT - Journal Article LG - English EM - 19980430 Revised: 20001218. Entry Week: 19980430 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0740-3194o 249~Imaging of interstitial cryotherapy--an in vitro comparison of ultrasound, computed tomography, and magnetic resonance imagingF?Tacke,J. Speetzen,R. Heschel,I. Hunter,D.W. Rau,G. Gunther,R.W.G 1999 5/1999*Cryosurgery/mt [Methods] Animal Comparative Study Cryotherapy Evaluation Studies Freezing Ice In Vitro Liver Liver/ra [Radiography] Liver/su [Surgery] Liver/us [Ultrasonography] Magnetic Resonance Imaging methods Swine Temperature Tomography,X-Ray Computed United States Water250-259 Cryobiology383,%RATIONALE AND OBJECTIVES: To evaluate the imaging capabilities of ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in monitoring interstitial cryotherapy and to compare them with visual control. METHODS: An experimental MR-compatible, vacuum-insulated and liquid nitrogen-cooled cryoprobe was inserted under in vitro conditions into a porcine liver, which was kept at a temperature of 37 +/- 1 degrees C, in a water bath with continuous stirring. The freezing procedure was controlled macroscopically, by US (Toshiba Sonolayer, 7.5-MHz linear array transducer), by CT (Siemens Somatom Plus, slice thickness 2-8 mm, 165-210 mA at 120 kV), and by MRI (Philips Gyroscan ACS-NT, FFE TR/TE/FA = 15/5.4/25 degrees, T1-SE 550/20, T2-TSE 1800/100) after the iceball reached its maximum size. RESULTS: The maximum iceball diameter around the probe tip was 12.0 mm by visual control, 12.4 mm by US, 12.7 mm by CT, and within 12.8 mm by spin echo sequences and 11 mm by gradient echo sequence. Due to the nearly signal-free appearance of the frozen tissue on MR images, the ice/tissue contrast on T1-weighted and gradient echo images was superior to T2-weighted images and CT images. Sonographically, the ice formation appeared as a hyperechoic sickle with nearly complete acoustic shadowing. CONCLUSION: Due to the better ice/tissue contrast, T1-weighted or gradient echo MR images were superior to CT and US in monitoring interstitial cryotherapy. Gradient echo sequences generally underestimated the ice diameter by 15%. Copyright 1999 Academic Press}DB - MEDLINE UI - 99262351 IN - Department of Diagnostic Radiology, University of Technology, Aachen, Germany. tacke@rad.rwth-aachen.de JC - dt3, DT3, DT3, 0006252 Journal Subset Index Medicus CP - United States PT - Journal Article LG - English EM - 19990706 Revised: 20001218. Entry Week: 19990706 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0011-2240xrMR-guided percutaneous cryotherapy of the liver: in vivo evaluation with histologic correlation in an animal modelLETacke,J. Adam,G. Haage,P. Sellhaus,B. Grosskortenhaus,S. Gunther,R.W.r 2001 1/2001Animal complications Cryosurgery Cryotherapy Feasibility Studies Follow-Up Studies instrumentation Liver Magnetic Resonance Imaging Male Necrosis pathology surgery Swine Time Factors United StatesUI - 21096038 LA - eng PT - Journal Article DA - 20010222 IS - 1053-1807 SB - IM CY - United States JC - BEO RefMgr field[1]: Journal RefMgr field[8]: Not in File 50-56J.Magn Reson.Imaging131The purpose of this study was to evaluate the feasibility of MR-guided percutaneous cryotherapy of the porcine liver and to correlate the resulting tissue necrosis with MR imaging and histology. Using an MR- compatible, argon-based cryotherapy system (CryoHit; Galil Medical Ltd., Israel) with 2- and 3-mm diameter tapered cryotherapy probes, MR- guided percutaneous cryotherapy was performed in seven pigs (mean body weight, 40 kg) under general anesthesia in a short-bore magnet (1.5 T ACS NT; Philips, The Netherlands) using an ultrafast T2-weighted single- shot LoLo TSE sequence and a T1-weighted gradient-echo sequence. The frozen liver tissue was depicted accurately on fast T2- and T1-weighted sequences, providing precise delineation of the ablated tissue volume. On follow-up postcontrast MR controls, the cryolesions appeared avascular. They decreased in size compared with the initially frozen volume down to 70% at a 2-week follow-up. Histologically, a coagulation necrosis with a close correlation to the MR follow-up examinations was objectified. No cryotherapy-related complications occurred. J. Magn. Reson. Imaging 2001;13:50-56. Copyright 2001 Wiley-Liss, Inc'Department of Diagnostic Radiology, University of Technology, Pauwelsstrasse 30, 52074 Aachen, Germany. tacke@rad.rwth-aachen.de499 PM:11169803 1130965451 2001Jan-FebRLAblation of liver metastasis: is preoperative imaging sufficiently accurate? 98-107.'The recent introduction of cryotherapy and radiofrequency ablation of liver metastasis has expanded the indications for treatment. As technology has advanced, a percutaneous approach has been developed. Percutaneous treatment, however, requires accurate preoperative imaging. From 1993 to 1999, 179 patients underwent operative exploration for treatment of suspected hepatic metastases from colorectal carcinoma. One hundred seventy-seven patients were staged by preoperative CT, two patients were staged by MRI, and complete data were available in 176. Hepatic tumor count by preoperative imaging was compared to intraoperative tumor count obtained by inspection, palpation, ultrasonographic examination using a 3.5/7.5 MHz T probe, and careful gross sectioning of the resected specimen. Post hoc analysis was performed on 35 CT scans by two radiologists who specialize in abdominal CT. These radiologists were blinded to the intraoperative findings. Their interpretations were compared to the intraoperative counts and to each other. Thirty-four (19%) of 179 patients were deemed untreatable at operation because of unsuspected overwhelming liver involvement in 11 (6%) or extrahepatic metastases in 23 (13%). For the group, CT was accurate in 80 patients (45%), showed more lesions than were found in 16 (9%), and showed fewer metastases than were found in 80 (45%). When the preoperative scan predicted a solitary metastasis, it was correct in 45 (65%) of 69 patients and underestimated disease in 24 (35%). In the post hoc analysis, the mean numbers of lesions reported by the two radiologists did not differ from the mean number of tumors found; however, the radiologists' counts agreed on 16 (59%) and disagreed on 11 (41%) of the scans. The accuracy of CT decreased with increasing numbers of lesions. Regardless of the type of preoperative imaging, intraoperative findings altered the course of the operation in 96 (55%) of 176 patients. Preoperative imaging is not sufficiently accurate to permit adequate percutaneous treatment of hepatic metastases from colorectal carcinoma.'~wDepartment of Surgery, Medical College of Wisconsin, 9200 W. Wisconsin Ave., Milwaukee, WI 53226, USA. jwallace@mcw.edu^XWallace, J. R. Christians, K. K. Quiroz, F. A. Foley, W. D. Pitt, H. A. Quebbeman, E. J.2,1091-255x Journal Article Validation StudiesJ Gastrointest SurgBias (Epidemiology) Catheter Ablation Colorectal Neoplasms/*pathology Comparative Study Cryosurgery Human Liver Neoplasms/*radiography/*secondary/surgery Magnetic Resonance Imaging/*standards Monitoring, Intraoperative/standards Neoplasm Staging/*methods/standards Preoperative Care/*methods/standards Sensitivity and Specificity Single-Blind Method Time Factors Tomography, X-Ray Computed/*standards Ultrasonography/standardslehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11309654 pjCreation of radiofrequency lesions in a porcine model: correlation with sonography, CT, and histopathology:4Raman,S.S. Lu,D.S. Vodopich,D.J. Sayre,J. Lassman,C. 200011/20004adverse effects Animal Catheter Ablation Comparative Study Contrast Media Disease Models,Animal Heat Hemorrhage Hyperemia Image Processing,Computer-Assisted Liver Liver Diseases methods Necrosis pathology Radiographic Image Enhancement radiography Support,Non-U.S.Gov't Swine Time Factors Tomography,X-Ray Computed Ultrasonography Ultrasonography,Doppler Ultrasonography,Doppler,Color Ultrasonography,Interventional United StatesUI - 20498642 LA - eng RN - 0 (Contrast Media) PT - Journal Article DA - 20001102 IS - 0361-803X SB - AIM SB - IM CY - UNITED STATES JC - 3AE RefMgr field[1]: Journal RefMgr field[8]: Not in File 1253-1258AJR Am.J.Roentgenol. 1755|OBJECTIVE: We studied the correlation between sonographic and CT appearances of radiofrequency thermal lesions created in porcine liver and histopathologic findings to evaluate the accuracy of these techniques in revealing the extent of tissue necrosis. MATERIALS AND METHODS: We used sonographic guidance and a 2.0-cm-diameter, eight- prong retractable radiofrequency electrode to view 12 hepatic lesions that were created in five pigs. Biphasic helical CT was performed 12-48 hr after ablation. The animals were sacrificed immediately after CT, and their livers were histopathologically examined. The maximum lesion size in the long and short axes as measured on CT and sonography was then correlated with the histopathologically determined lesion size. RESULTS: On sonography, lesions changed rapidly within 5 min after the termination of ablation. An early echogenic cloud became peripherally hypoechoic with a variable thin echogenic rim. Early (0-2 min after ablation) sonograms led to an underestimation of true lesion sizes on histopathology (r = 0.3-0.49; p < 0.05). Delayed (2-5 min after ablation) sonograms also led to an underestimation of true lesion size (r = 0.5-0.62; p < 0.05); however, lesions were larger and better demarcated. Biphasic contrast-enhanced helical CT revealed avascular lesions surrounded by hyperemic rims that closely correlated with true pathologic lesions size (r = 0.93-0.95; p < 0. 05). Lesions with hyperemic rims that were measured on CT led to overestimations of true lesion size. CONCLUSION: Sonography led to underestimations of the true size of ablated lesions within the first 5 min after creation; however, delayed images provided better results. The avascular lesion measured on contrast-enhanced helical CT closely correlated with the size of ablated tissue; therefore, contrast-enhanced CT is preferred for serially monitoring the effect of radiofrequency ablation'xqDepartment of Radiological Sciences, UCLA School of Medicine, 10833 LeConte Ave., Los Angeles, CA 90095-1721, USAo199 PM:11044017 !  <44Thermal lesion conspicuity following interstitial radiofrequency thermal tumor ablation in humans: a comparison of STIR, turbo spin-echo T2-weighted, and contrast-enhanced T1-weighted MR images at 0.2 T@:Aschoff,A.J. Rafie,N. Jesberger,J.A. Duerk,J.L. Lewin,J.S. 200010/2000NH*Catheter Ablation *Hyperthermia,Induced *Liver Neoplasms/th [Therapy] *Magnetic Resonance Imaging/mt [Methods] 0 (Contrast Media) Adult Aged Comparative Study Contrast Media Female Human Liver Liver Neoplasms/pa [Pathology] Liver Neoplasms/sc [Secondary] Liver/pa [Pathology] Male Middle Age Support,Non-U.S.Gov't United States584-589g,%Journal of Magnetic Resonance Imagingr124 The purpose of this study was to compare the contrast between radiofrequency (RF) thermal liver lesions and surrounding tissue in T2-weighted turbo spin-echo sequences (TSE T2), short TI inversion recovery techniques (STIR), and contrast-enhanced (CE) T1-weighted spin-echo images. Nineteen RF thermal ablations were performed on eight patients with metastatic liver tumors. After ablation, contrast-to-noise ratios (CNRs) were calculated between mean signal amplitudes from three regions of interest (ROI) (lesion, surrounding edema, and normal tissue) using TSE T2-weighted, STIR, and contrast-enhanced T1-weighted (CE T1) sequences for each lesion. CNRs between the thermal lesion and normal liver tissue for both TSE T2-weighted (mean 0.9) and STIR (2.0) images were significantly lower than for CE T1-weighted (8.4) images (t-test, alpha = 0.05). However, CNRs between edema rim and the core of the thermal lesion for both TSE T2-weighted (8.1) and STIR images (7.2) were not significantly different (t-test, alpha = 0.05) from CNRs between lesion and normal tissue for CE T1-weighted images (8.4), nor was the CNR between edema rim and normal tissue for both TSE T2-weighted (10.3) and STIR (9.8) images. Although the edema was not visible on CE T1-weighted images, 18 of 19 lesions (94.7%) were surrounded by a hyperintense rim on TSE T2-weighted or STIR images. Both TSE T2-weighted and STIR sequences represent valid techniques for repeatable assessment of RF thermal lesions. Copyright 2000 Wiley-Liss, InczDB - MEDLINE UI - 20499555 IN - Department of Radiology, University Hospitals of Cleveland/Case Western Reserve University, Cleveland, Ohio 44106, USA JC - beo, BEO, BEO, 9105850 Journal Subset Index Medicus CP - United States PT - Journal Article LG - English EM - 20001120. Entry Week: 20001120 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 1053-180750~xUse of CT Hounsfield unit density to identify ablated tumor after laparoscopic radiofrequency ablation of hepatic tumorsZTBerber,E. Foroutani,A. Garland,A.M. Rogers,S.J. Engle,K.L. Ryan,T.L. Siperstein,A.E. 2000 9/2000TN*Adenocarcinoma/ra [Radiography] *Adenocarcinoma/su [Surgery] *Catheter Ablation *Liver Neoplasms/ra [Radiography] *Liver Neoplasms/su [Surgery] *Neuroendocrine Tumors/ra [Radiography] *Neuroendocrine Tumors/su [Surgery] *Tomography,X-Ray Computed Adult Aged Female Human Liver Male methods Middle Age surgery Perfusion Adenocarcinoma799-804MSurgical Endoscopy149eBACKGROUND: When attempting to interpret CT scans after radiofrequency thermal ablation (RFA) of liver tumors, it is sometimes difficult to distinguish ablated from viable tumor tissue. Identification of the two types of tissue is specially problematic for lesions that are hypodense before ablation. The aim of this study was to determine whether quantitative Hounsfield unit (HU) density measurements can be used to document the lack of tumor perfusion and thereby identify ablated tissue. METHODS: Liver spiral CT scans of 13 patients with 51 lesions undergoing laparoscopic RFA for metastatic liver tumors within a 2-year time period were reviewed. HU density of the lesions as well as normal liver were measured pre- and postoperatively in each CT phase (noncontrast, arterial, portovenous). Statistical analyses were performed using Student's paired t-test and ANOVA. RESULTS: Normal liver parenchyma, which was used as a control, showed a similar increase with contrast injection in both pre- and postprocedure CT scans (56.4 +/- 2.4 vs 57.1 +/- 2.4 HU, respectively; p = 0.3). In contrast, ablated liver lesions showed a preablation increase of 45.7 +/- 3.4 HU but only a minimal postablation increase of 6.6 +/- 0.7 HU (p < 0.0001). This was true for highly vascular tumors (neuroendocrine) as well as hypovascular ones (adenocarcinoma). CONCLUSIONS: This is the first study to define quantitative radiological criteria using HU density for the evaluation of ablated tissues. A lack of increase in HU density with contrast injection indicates necrotic tissue, whereas perfused tissue shows an increase in HU density. This technique can be used in the evaluation of patients undergoing RFAd|DB - MEDLINE UI - 20457509 IN - Department of General Surgery, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA JC - vbf, VBF, VBF, 8806653 Journal Subset Index Medicus CP - Germany PT - Journal Article LG - English EM - 20001019 Revised: 20001218. Entry Week: 20001019 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0930-27946715003e313 1984 MarXQThe polyacrylamide as a phantom material for electromagnetic hyperthermia studies 317-22HBBini, M. G. Ignesti, A. Millanta, L. Olmi, R. Rubino, N. Vanni, R. 0018-9294 Journal ArticleDIEEE Trans Biomed Engl*Acrylic Resins Animal Electric Conductivity *Electromagnetic Fields *Electromagnetics *Gels Human *Hyperthermia, Induced *Models, Structuraljdhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=6715003d]MR monitoring of MR-guided radiofrequency thermal ablation of normal liver in an animal modelhJCBoaz,T.L. Lewin,J.S. Chung,Y.C. Duerk,J.L. Clampitt,M.E. Haaga,J.R.9 1998 1/1998anatomy & histology Animal Catheter Ablation Contrast Media diagnostic use Gadolinium DTPA instrumentation Liver Magnetic Resonance Imaging Male methods Rabbits Radiology,Interventional Support,Non-U.S.Gov't surgery United StatesUI - 98159898 LA - eng RN - 0 (Contrast Media) RN - 80529-93-7 (Gadolinium DTPA) PT - Journal Article DA - 19980423 IS - 1053-1807 SB - IM CY - UNITED STATES JC - BEO RefMgr field[1]: Journal RefMgr field[8]: Not in File 64-69J.Magn Reson.Imaging81,%In vivo rabbit, titanium alloy probe. The purpose of this study was to determine the suitability of MRI to accurately detect radiofrequency (RF) thermoablative lesions created under MR guidance. In vivo RF lesions were created in the livers of six New Zealand White rabbits using a 2-mm-diameter titanium alloy RF electrode with a 20-mm exposed tip and a 50-W RF generator. This was performed using a 0.2T clinical C-arm MR imager for guidance and monitoring. Each animal was sacrificed and gross evaluation was performed. Histologic correlation was performed on the first two animals. The MR-compatible RF electrode was easily identified on rapid gradient-echo images used to guide electrode placement. A single lesion was created in each rabbit liver. Lesions ranged from approximately 10 to 17 mm in diameter (mean, 13.5 mm). T2-weighted and short T1 inversion recovery (STIR) images demonstrated lesions ranging in diameter from 12 to 18 mm (mean, 14.6 mm). Lesion dimensions determined from images closely correlated with those determined at gross examination with the discrepancy never exceeding 2 mm, for an r2 value of .87. MRI performed at the time of MR-guided RF ablation accurately demonstrated created lesions. This modality may provide a new option for the treatment of local and regional neoplastic disease'piDepartment of Radiology, University Hospitals of Cleveland/Case Western Reserve University, OH 44106, USA141 PM:9500262#   360PICT of the liver after cryotherapy of hepatic metastases: imaging findingsvD=McLoughlin,R.F. Saliken,J.F. McKinnon,G. Wiseman,D. Temple,W.s 1995 8/1995@:*Cryotherapy *Liver Neoplasms/ra [Radiography] *Liver Neoplasms/sc [Secondary] *Liver/ra [Radiography] *Tomography,X-Ray Computed Aged blood complications Cryotherapy diagnosis Diagnosis,Differential Female Follow-Up Studies Human Liver Liver Neoplasms/th [Therapy] Male Middle Age Safety Temperature United States329-332 ,%AJR.American Journal of Roentgenologyh 165d2 F?Cryotherapy is the in situ destruction of abnormal tissue using subzero temperatures (Fig. 1). Recent studies have demonstrated the technical feasibility, safety, and effectiveness of hepatic cryotherapy in the treatment of liver tumors and 2 over black square];.[1 and 2 over black square], 2]. Such treatment can be precisely focused on the tumor, thereby preserving surrounding normal tissue. In addition, because major vessels with flowing blood are protected from cryoablation, tumors adjacent to these vessels can be treated without sacrificing vasculature. Hepatic cryoablation is therefore particularly suitable for patients who do not qualify for surgical resection because of multiple metastases involving both lobes of the liver, or because of lesions close to major blood vessels. After the procedure, CT during arterioportography is of little value in distinguishing cryolesion from malignant tumor (Fig. 2), and CT with IV contrast enhancement is recommended for follow-up. It is important to distinguish CT findings of successful and unsuccessful treatment, treatment complications such as abscess and cholestasis, and recurrent tumor. The purpose of this essay is to illustrate the findings on CT with IV contrast enhancement in various situations, emphasizing features that are useful in making accurate differential diagnosisyDB - MEDLINE UI - 95343841 IN - Department of Radiological Sciences and Diagnostic Imaging, Foothills Hospital, Calgary, Alberta, Canada JC - 3ae, 3AE, 3AE, 7708173 Journal Subset AIM Journals CP - United States PT - Journal Article LG - English EM - 199508 Revised: 20001218. Entry Week: 199508 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0361-803X11461867 177 21 2001 AugHepatocellular carcinoma treated with radiofrequency ablation: comparison of pulse inversion contrast-enhanced harmonic sonography, contrast-enhanced power Doppler sonography, and helical CT 375-80OBJECTIVE: The purpose of this study was to compare the efficacy of contrast-enhanced pulse inversion harmonic imaging with contrast-enhanced power Doppler sonography and helical CT to determine incomplete local treatment after radiofrequency ablation in patients with hepatocellular carcinoma. MATERIALS AND METHODS: Thirty-five consecutive patients (24 men and 11 women; mean age, 64 years) with 43 hepatocellular carcinomas (3.6 +/- 1.1 cm) were treated using internally cooled radiofrequency ablation therapy. Therapeutic response was evaluated at 4 months with dual-phase contrast-enhanced helical CT, conventional power Doppler Sonography, and pulse inversion harmonic imaging using a sonographic contrast agent (SH-508). CT and sonographic studies were reviewed separately in random order by four radiologists at different consensus conferences. Sensitivity and specificity of the sonographic methods were determined using CT as a gold standard and results were compared using the McNemar test. RESULTS: CT examinations identified residual tumor in 12 lesions (27.9%). Although conventional contrast-enhanced power Doppler sonography identified residual viable tumor foci in four incompletely treated lesions (9.3%), contrast-enhanced pulse inversion harmonic imaging identified residual tumoral enhancement in 10 lesions (23.3%). Thus, the sensitivity of pulse inversion harmonic imaging (83.3%) was significantly greater (p < 0.05) for detecting residual nonablated tumor compared with conventional contrast-enhanced power Doppler sonography. CONCLUSION: Our study suggests that contrast-enhanced pulse inversion harmonic imaging may enable the detection of residual nonablated tumor in more cases than contrast-enhanced power Doppler sonography and may ultimately prove to be a useful adjunct for percutaneous ablation therapies. Nevertheless, contrast-enhanced axial imaging (CT or MR imaging) is currently the most sensitive test for managing thermal ablation for patients with hepatocellular carcinoma.'`ZServizio di Radiologia, Ospedale Civile via Cesare, Battisti 25, Vimercate, Milano, Italy.ngMeloni, M. F. Goldberg, S. N. Livraghi, T. Calliada, F. Ricci, P. Rossi, M. Pallavicini, D. Campani, R.Journal ArticleAJR Am J Roentgenol.'Carcinoma, Hepatocellular/radiography/*surgery/ultrasonography *Catheter Ablation Comparative Study Contrast Media Female Human Liver Neoplasms/radiography/*surgery/ultrasonography Male Middle Age Neoplasm, Residual Sensitivity and Specificity Tomography, X-Ray Computed Ultrasonography, Dopplerrkhttp://www.ajronline.org/cgi/content/full/177/2/375 http://www.ajronline.org/cgi/content/abstract/177/2/375 392aComparison of iceball diameter and temperature distribution achieved with 3-mm accuprobe cryoprobes in porcine and human liver tissue and human colorectal liver metastases in vitroNGPopken,F. Seifert,J.K. Engelmann,R. Dutkowski,P. Nassir,F. Junginger,T.d 2000 6/2000"*Cryosurgery/is [Instrumentation] *Liver Neoplasms/sc [Secondary] *Liver Neoplasms/su [Surgery] *Liver/su [Surgery] Animal Colorectal Neoplasms Comparative Study Cryosurgery/mt [Methods] Evaluation Studies Human Ice In Vitro Liver Support,Non-U.S.Gov't Swine Temperature United States302-310 Cryobiology404We aimed to assess the thermal profile and size of iceballs produced by Accuprobe cryoprobes in fresh porcine and human liver and human colorectal cancer liver metastases in vitro to allow better planning of cryosurgical treatment of liver metastases. Iceballs were produced by a 20-min single freeze cycle using 8-mm cryoprobes in pig liver in a waterbath at 37 degrees C (n = 8) and 3-mm cryoprobes in pig liver (n = 8), human liver (n = 3), and human colorectal cancer liver metastases (n = 8). The iceball diameters and the temperatures at different distances from the cryoprobe were measured. Mean iceball diameters produced by 8-mm cryoprobes in pig liver were 56.3 mm and varied from 38.7 to 39.6 mm for 3-mm cryoprobes in the different tissues used. There was no significant difference in iceball size in the different tissues. The diameter of the zone of -40 degrees C or less was approximately 44 mm using 8-mm cryoprobes in porcine liver and between 27 and 31 mm using 3-mm cryoprobes in the different tissues examined. The results may allow better preoperative planning of the cryosurgical treatment of liver metastases with Accuprobe cryoprobes. Copyright 2000 Academic PressDB - MEDLINE UI - 20384493 IN - Klinik fur Allgemein- und Abdominalchirurgie, der Johannes Gutenberg-Universitat, Langenbeckstr, 1, Mainz, 55101, Germany JC - dt3, DT3, DT3, 0006252 Journal Subset Index Medicus CP - United States PT - Journal Article LG - English EM - 20001006 Revised: 20001218. Entry Week: 20001006 RefMgr field[1]: Journal RefMgr field[8]: Not in File RefMgr field[26]: 0011-2240