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Fred T Lee

Publications and source records attributed to Fred T Lee.

At least 19 recordsLinked to original sources
PubMed2004

Imaging of murine liver tumor using microCT with a hepatocyte-selective contrast agent: accuracy is dependent on adequate contrast enhancement.

INTRODUCTION: A major limitation in using both spontaneous and implanted murine liver tumor models in cancer research is the inability to accurately detect and monitor tumor volume. Because microCT without contrast enhancement cannot accurately distinguish tumor from normal liver, we sought to determine the accuracy of contrast enhanced microCT for monitoring liver tumors in mice, performed with intravenous (i.v.) injection of ITG, a hepatocyte-selective contrast agent. METHODS: Twelve female BALB/c mice were injected with 5 x 10(5) CT26 tumor cells in two sites in the liver on day 0, resulting in 24 liver tumors. On days 3, 5, 7, and 10, three mice per day were injected with ITG (0.1 mL ITG/10 g body weight) by tail vein, followed 4 hours later by imaging with microCT (ImTek, Inc.). ITG is transported selectively to hepatocytes by an apoE receptor-mediated process that results in opacification of normal liver parenchyma after i.v. injection. Contrast enhancement on CT scans was graded as good, fair, or poor. After imaging, mice were euthanized to perform gross and histopathologic correlation of liver tumors with CT images. RESULTS: The mean tumor size on microCT and at histopathologic evaluation was 2.2 and 2.3 mm, respectively (P > 0.05). Regression analysis showed no difference between the CT-measured tumor and the actual tumor size (P > 0.05). The overall accuracy for detection of tumor on microCT was 88%, with one false-positive and two false-negative readings. All three erroneous readings on CT scan occurred in mice in which the contrast enhancement of the liver was poor due to inadequate i.v. injection. Although the overall sensitivity and specificity was 90% and 75%, respectively, this was highly dependent on the degree of contrast enhancement. CONCLUSIONS: MicroCT with ITG contrast is an excellent means to monitor tumor diameter in murine hepatic tumor models. However, adequate contrast enhancement is critical for accurate imaging.

Animals↗
PubMed2004

Image-guided ablation of renal cell carcinoma.

An increasing number of small asymptomatic renal cell carcinomas (RCCs) are being detected by cross-sectional imaging. Because of the nonaggressive biologic behavior of many of these tumors, there is increasing interest in minimally invasive treatment modalities,particularly for the elderly, infirm, and patients with comorbid conditions. Radiofrequency(RF) ablation, cryoablation, microwave ablation, and laser ablation have all shown promise for the treatment of RCC, with high local control and low complication rates for RF ablation and cryoablation. However, the clinical trial data remain early, and survival data are not yet available for a definitive comparison with conventional surgical techniques for removal of RCC.

Carcinoma, Renal Cell↗
PubMed2004

Laparoscopic cryoablation under sonographic guidance for the treatment of small renal tumors.

PURPOSE: To evaluate the efficacy of ultrasound-guided laparoscopic cryoablation of small renal tumors. PATIENTS AND METHODS: Eleven men and five women with solid renal tumors (mean size 2.6 cm) were treated using laparoscopically monitored cryoablation between October 2000 and October 2002. Nine tumors were left sided and seven right. Ten patients were treated retroperitoneoscopically and six transperitoneally. A double-freeze/active-thaw technique was utilized with two 10-minute freeze cycles. RESULTS: The mean operating time was 188 minutes. There was one open conversion for failure to progress. The mean blood loss was 40 mL. Tumor biopsy demonstrated five renal-cell carcinomas, two oncocytomas, and lesions that either were benign or were not biopsied. The mean hospital stay was 1.9 days with a median stay of 1 day. With a mean follow-up of 9.6 months, all tumors remain nonenhancing and are stable or smaller than the original lesion. Two patients have died of unrelated causes and without evidence of disease. CONCLUSIONS: This series of patients adds to the growing body of literature suggesting that cryoablation is a well-tolerated method for treating small renal tumors. Longer follow-up is required to fully define its place in the therapeutic armamentarium.

Adult↗
PubMed2004

Comparison of radiofrequency ablation, cryoablation, and nephrectomy in treating implanted VX-2 carcinoma in rabbit kidneys.

PURPOSE: To compare the efficacy of radiofrequency (RF) ablation, cryoablation, and radical nephrectomy in the treatment of implanted VX-2 carcinoma in rabbit kidneys. MATERIALS AND METHODS: Sixty-eight New Zealand White rabbits were implanted with 1-mm3 segments of VX-2 carcinoma in the left kidney. Seven days after implantation, the tumors were treated with one of the following: (1) RF ablation using a 12-gauge electrode (RITA Medical Systems, Mountain View, CA) at 90 degrees C for 8 minutes with a 5-mm tumor margin target temperature of 60 degrees C (N = 20); (2) cryoablation using a 15 minute double-freeze technique with 2.4-mm cryoprobes and the Cryocare system (Endocare Inc., Irvine, CA) with a 5-mm tumor margin target temperature of -20 degrees C (N = 20); (3) open radical nephrectomy (N = 20); or (4) no treatment (controls; N = 8). Rabbits were allowed to survive for a total of 22 days and sacrificed; and the kidneys, lungs, liver, spleen, urinary bladder, and ureter were removed and examined grossly and histologically for tumor. RESULTS: Findings in animals sacrificed at 15 days post-treatment showed significant differences between all treatment groups and untreated controls (P < 0.002) Using a 3 x 2 chi-square comparison, no differences in disease-free survival were observed between the RF ablation group, the cryoablation group, and the open nephrectomy group (P = 0.72) CONCLUSION: Radiofrequency ablation, cryoablation, and radical nephrectomy were all efficacious in the treatment of implanted VX-2 renal tumors compared with untreated controls (P = 0.002). No statistically significant difference was found between any of the three treatments.

Animals↗
PubMed2004

Comparison of cryotherapy and nephrectomy in treating implanted VX-2 carcinoma in rabbit kidneys.

OBJECTIVE: To compare the efficacy of cryoablation and radical nephrectomy for treating implanted VX-2 carcinoma in rabbit kidneys. MATERIALS AND METHODS: A pilot study was conducted using 27 New Zealand white rabbits to assess the natural history of VX-2 carcinoma in the kidney. VX-2 tumour segments (1 mm(3)) were excised from subcutaneous tumours in carrier rabbits and implanted in the left kidney of study rabbits. The tumours were allowed to grow for 6, 7, 8, 9, 10, 14, 18, 21 and 28 days after implantation. Tumour progression was analysed in the kidney and surrounding serosa, and metastatic tumour presence in the lung, liver, spleen and bladder determined. After this, 80 rabbits were implanted with VX-2 in the lower pole and randomized into one of three groups: group 1, 35 rabbits treated 7 days after VX-2 implantation with cryoablation using a 15-min double-freeze technique and a 5-mm tumour margin target temperature of - 20 degrees C; group 2, 35 rabbits treated with open radical nephrectomy; or group 3, 10 untreated controls. Rabbits were maintained for 22 days and then killed; the kidneys, lungs, liver, spleen, urinary bladder and ureter were removed, and examined grossly and histologically for tumour presence. RESULTS: In the pilot study there was a consistent 50-100 mm(3) tumour after 7 days of growth, with no evidence of metastatic disease. By day 10 the mean kidney tumour was 230 mm(3) and two of three rabbits had metastases in the lung. By day 18 the mean primary tumour was 5504 mm(3) and all rabbits had metastatic disease. In the comparison study, cryotherapy cured 66% of implanted rabbits while nephrectomy cured 64%. All untreated controls had significant local and metastatic tumours. Findings in animals killed at 15 days after treatment showed significant differences between both treatment groups and untreated controls (P < 0.002). There was no difference in disease-free survival between the cryotherapy and open nephrectomy groups (P = 0.78) CONCLUSION: Both cryoablation and radical nephrectomy were effective in treating implanted VX-2 renal tumours compared with untreated controls. There was no statistically significant difference between cryoablation and nephrectomy.

Animals↗
PubMed2004

Elastographic versus x-ray CT imaging of radio frequency ablation coagulations: an in vitro study.

Techniques to image elasticity parameters (i.e., elastography) have recently become of great interest to researchers. In this paper we use conventional ultrasound elastography and x-ray CT to image radio frequency (RF) ablation sites of excised canine liver enclosed in gelatin. Thermal coagulations of different sizes were produced by applying the RF procedure for various times and end point temperatures. Dimensions, areas and volumes computed from CT and elastography were compared with those on whole mount pathology specimens. Ultrasound elastography exhibited high contrast for the thermal coagulations and performed better than CT. The correlation between pathology and elastography for this sample set of 40 thermal coagulations (r = 0.94 for volume estimation, r = 0.87 for area estimation) is better than the correlation between pathology and CT (r = 0.89 for volume estimation, r = 0.82 for area estimation).

Animals↗
PubMed2004

Microwave ablation with loop antenna: in vivo porcine liver model.

PURPOSE: To determine the effectiveness of tissue ablation with a loop microwave antenna in various configurations in porcine liver tissue. MATERIALS AND METHODS: Microwave energy was applied for 7 minutes at 60 W in six porcine livers (mean weight, 68.2 kg) by using single (n = 7) or dual 2.7-cm loop microwave probes in parallel (n = 9) or orthogonal (n = 9) configurations. Volume, diameter, shape, and temperature of the zone of necrosis and the presence of viable tissue inside the loop were determined and compared by means of factorial analysis of variance. RESULTS: Mean lesion volume and maximum diameter, respectively, were 32.2 cm(3) +/- 14.4 (SD) and 4.6 cm +/- 1.4 for lesions ablated with parallel probes (parallel lesions), 29.5 cm(3) +/- 8.1 and 4.3 cm +/- 0.6 for lesions ablated with orthogonal probes (orthogonal lesions), and 6.4 cm(3) +/- 1.9 and 3.4 cm +/- 0.62 for lesions ablated with single probes (single lesions) (P <.05, single vs parallel and orthogonal lesions). Mean minimum diameter was greatest for orthogonal lesions (3.5 cm +/- 0.53; P =.017, parallel vs orthogonal lesions). Orthogonal lesions had the highest mean internal temperature (97.2 degrees C) versus parallel (91.9 degrees C) and single (60.0 degrees C) lesions. All orthogonal lesions heated to 60 degrees C in comparison to eight of nine parallel and four of seven single lesions. The mean time to reach 60 degrees C was shortest for orthogonal lesions (93.3 seconds) versus parallel (123.8 seconds) and single (263.0 seconds) lesions. Orthogonal lesions were the most spherical. Viable tissue was present in the center of five of seven single, six of nine parallel, and zero of nine orthogonal lesions. CONCLUSION: Loop microwave antennas allow precise control and effective ablation of targeted tissue, particularly in the orthogonal configuration.

Animals↗
PubMed2004

Impact of gas bubbles generated during interstitial ablation on elastographic depiction of in vitro thermal lesions.

OBJECTIVE: Artifacts from gas bubble formation during radio frequency ablation along with the poor intrinsic contrast between normal and treated regions (zone of necrosis) are considerable problems for the visualization of the necrotic region on conventional sonography. Sonographic elastography is very effective for visualizing the zone of necrosis, but it uses the same echo signals to estimate strain as those used to form gray scale images. Thus, the impact of gas bubbles on strain images or elastograms must be investigated. METHODS: Radio frequency ablation was performed in vitro on liver tissue samples, approximately 40 x 40 x 20 mm, encased in 80-mm cubed gelatin phantoms. Elastograms generated at different instants during the ablation procedures were obtained on a real-time scanner with a 5-MHz linear array. Sequences of elastograms illustrate the growth of the thermal lesion. RESULTS: Degradation of the distal boundary of the thermal lesion was observed. The degradation was confined to the lower-fifth quadrant of the thermal lesion. However, accurate estimates of lesion areas could still be obtained by extrapolation of the thermal lesion boundary. CONCLUSIONS: Elastograms of thermal lesions in vitro can be obtained during radio frequency ablation. Some loss of thermal lesion boundary information on strain images was observed in regions where attenuation due to gas bubbles reduced the signal-noise ratio of the echo signals.

Animals↗
PubMed2003

Postbiopsy bleeding in a porcine model: reduction with radio-frequency ablation--preliminary results.

PURPOSE: To test a biopsy needle modified for use of radio-frequency (RF) energy to produce hemostasis after core biopsy of liver or kidney. MATERIALS AND METHODS: RF energy was applied to a partially insulated 17-gauge needle, and tip temperature was monitored with a thermocouple. Domestic Yorkshire pigs (n = 4; mean weight, 23.4 kg) were anesthetized, and their livers and kidneys were exposed. Needles were inserted 2 cm into hepatic and renal parenchyma and retracted, either with or without tract ablation to 65 degrees C, in normal tissue, animals treated with anticoagulants, and an animal with acute inferior vena caval occlusion to produce portal hypertension. Blood loss was assessed by weighing surgical sponges with blood from the puncture sites. Significant differences in blood loss between control and ablated biopsy specimens in each scenario were tested by using a Wilcoxon matched-pairs signed rank test. RESULTS: Mean blood loss for each group was as follows: In the liver, control biopsy specimens (n = 18) lost 0.30 g while ablated biopsy specimens lost 0.00044 g (P <.01), and control biopsy specimens treated with heparin (n = 26) lost 0.45 g while biopsy specimens treated with heparin and ablation lost 0.27 g (P =.03). For inferior vena caval occlusion, control biopsy specimens lost 1.23 g, while ablated biopsy specimens lost 0.00 g. In the kidney, control biopsy specimens (n = 28) lost 0.82 g, while ablated biopsy specimens lost 0.24 g (P =.01), and control biopsy specimens treated with heparin (n = 14) lost 1.04 g, while biopsy specimens treated with heparin and ablation lost 0.19 g (P =.02). CONCLUSION: Tract ablation with thermocouple-monitored RF energy decreased postprocedural hemorrhage after hepatic and renal biopsy.

Animals↗
PubMed2003

Bipolar radiofrequency ablation of the kidney: comparison with monopolar radiofrequency ablation.

PURPOSE: We report initial ex vivo and in vivo studies using bipolar radiofrequency (RF) ablation of porcine kidneys. An internal ground electrode is positioned in the kidney opposite the RF electrode, resulting in ablation of all the intervening renal tissue. MATERIALS AND METHODS: Ex vivo preparations of 10 porcine kidneys were perfused continuously with Ringer's solution and treated with either standard external grounded RF (N = 3) or bipolar RF ablation with 1 (N = 2), 2 (N = 3), or 3 (N = 2) cm of separation between the ground probe and the RF probe using a Model 30 RITA generator (RITA, Mountain View, CA). Target temperatures were 90 degrees C for 8 minutes. Gross and histologic assessments were made acutely. Four domestic pigs were treated with monopolar RF ablation of the lower pole of one kidney and bipolar RF with a 12-mm separation between the probes of the contralateral lower pole. Animals were harvested 48 hours later to maximize tissue damage for gross measurements and histologic evaluation. RESULTS: Ex vivo studies revealed grossly monopolar lesions 1.5 cm in maximum diameter and 1.75 cm(3) in volume. In comparison, bipolar lesions were 2.8 cm in maximum diameter and 10.3 cm(3) in volume using 3 cm of electrode separation. There was histologic evidence of cell death in all specimens. In vivo studies showed two distinct gross lesions with RF: one blanched and one hemorrhagic. Using bipolar RF, larger blanched lesions were achievable than with monopolar RF (2.80 cm(3) v 1.63 cm(3)). Overall, the combinations of blanched and hemorrhagic lesions were similar with monopolar and bipolar RF (5.01 v 5.31 cm(3)). Histologic evaluation verified cell death in the blanched lesions and rare areas of normal tissue in the hemorrhagic lesions. CONCLUSIONS: As shown by ex vivo data, bipolar RF can create larger lesions than does monopolar RF. In vivo, at 48 hours, both blanched and hemorrhagic gross lesions were seen using RF. In this model, blanched lesions predominated when performing bipolar RF.

Animals↗
PubMed2003

Multiple probe radiofrequency ablation: pilot study in an animal model.

PURPOSE: Radiofrequency ablation (RFA) is becoming increasingly popular for the minimally invasive treatment of benign and malignant tumors. Currently available systems are limited to the use of a single probe because of electrical interactions between probes. The purpose of this study was to test a new prototype multiple probe generator with a built-in switching mechanism to determine if multiple zones of necrosis could be formed simultaneously without a significant penalty in terms of lesion size and procedure time. MATERIALS AND METHODS: A dual probe generator was created by modifying a commercially available system into an alternating monopolar system with an external electronic switch controlled by a temperature feedback loop. A total of 20 radiofrequency (RF) lesions (conventional single probe, n = 10; switched dual probe, n = 10) were created in the livers of six adult pigs (temperature, 100 degrees C; 10-minute ablation). Lesions were excised and examined for volume, minimum diameter, and maximum diameter. RESULTS: The time to target temperature was slightly greater for dual (3.5 minutes) versus single ablations (2.7 minutes). However, this resulted in only a 48 second (6.5%) longer total ablation time. There was no significant difference between conventional single and dual lesions for lesion volume (13.6 +/- 9.3 cm(3) versus 13.7 +/- 7.0 cm(3); P >.05), minimum diameter (1.63 +/- 0.56 cm(3) versus 1.61 +/- 0.53; P >.05) or maximum diameter (3.3 +/- 0.84 versus 3.4 +/- 0.55, P >.05). CONCLUSION: A multiple probe RFA system that can simultaneously ablate multiple areas in the liver is feasible. If multiple probe units become clinically available, large or irregularly shaped lesions could be treated more effectively than with conventional single probe units, and multiple tumors could be ablated simultaneously, thus potentially decreasing procedure time and anesthetic complications.

Animals↗
PubMed2003

Hepatic radiofrequency ablation with internally cooled probes: effect of coolant temperature on lesion size.

Radiofrequency (RF) ablation is a minimally invasive method for treatment of primary and metastatic liver tumors. One of the currently commercially available devices employs an internally cooled 17-gauge needle probe. Within the probe, cool water is circulated during ablation, which cools tissue close to the probe resulting in larger lesions. We evaluated the effect of different cooling water temperatures on lesion size. We created a finite-element method model, simulated 12 min impedance-controlled ablation and determined temperature distribution for three water temperatures. Lesion diameters in the model were 33.8, 33.4, and 32.8 mm for water temperatures of 5 degrees C, 15 degrees C, and 25 degrees C, respectively. We solved a simplified model geometry analytically and present dependence of lesion diameter on cooling temperature. We further performed ex vivo experiments in fresh bovine liver. We created four lesions for each water temperature, with the same water temperatures as used in the finite-element method (FEM) model. Average lesion diameters were 28.3, 30, and 29.5 mm for water temperatures of 5 degrees C, 15 degrees C, and 25 degrees C, respectively. Water temperature did not have a significant effect on lesion size in the ex vivo experiments (p = 0.76), the FEM model, and the analytical solution.

Animals↗
PubMed2003

Image-guided tumor ablation: proposal for standardization of terms and reporting criteria.

The field of image-guided tumor ablation requires standardization of terms and reporting criteria to facilitate effective communication of ideas and appropriate comparison between treatments with different technologies, such as chemical ablation (ethanol or acetic acid) and thermal therapies, such as radiofrequency, laser, microwave, ultrasound, and cryoablation. On the basis of this premise, a working committee was established with the goal of producing a proposal on such standardization. The intent of the Working Group is to provide a framework that will facilitate the clearest communication between investigators and will provide the greatest flexibility in comparisons between the many new, exciting, and emerging technologies. The members of the Working Group now propose a vehicle for reporting the various aspects of image-guided ablation therapy, including classifications of therapies and procedures, appropriate descriptors of image guidance, and terms to define imaging and pathologic findings. Methods for standardizing the reporting of follow-up findings and complications and other important aspects that require attention when reporting clinical results are addressed. It is the group's hope and intention that adherence to the recommendations of this proposal will facilitate achievement of the group's main objective: improved precision and communication in this field that lead to more accurate comparison of technologies and results and ultimately to improved patient outcomes.

Catheter Ablation↗
PubMed2003

Hepatic microwave ablation with multiple antennae results in synergistically larger zones of coagulation necrosis.

BACKGROUND: Microwave ablation is a promising treatment for unresectable liver tumors. Unlike radiofrequency ablation, microwave ablation may be performed with multiple simultaneously active antennae. METHODS: Microwave ablation was performed in an in vivo porcine liver model by using a single antenna (n = 11) or three antennae in a triangular array, activated either sequentially (n = 11) or simultaneously (n = 13). Lesions were measured and assigned a qualitative shape score. RESULTS: Single-antenna microwave lesions had a mean volume of 7.4 +/- 3.9 cm(3), compared with 14.6 +/- 5.2 cm(3) and 43.1 +/- 4.3 cm(3) for sequential and simultaneous multiple-probe ablations, respectively (P <.001; analysis of variance). Simultaneous lesions were rounder than sequential ablations and were more effective near blood vessels. Simultaneous lesions created with probe separation of < or =1.7 cm were round and confluent, whereas clefts were present with distances >1.7 cm (P <.001). CONCLUSIONS: Microwave ablation has several theoretical advantages over currently available radiofrequency devices. Simultaneous three-probe microwave ablation lesions were three times larger than sequential lesions and nearly six times greater in volume than single-probe lesions. Additionally, simultaneous multiple-probe ablation results in qualitatively better lesions, with more uniform coagulation and better performance near blood vessels. Simultaneous multiple-probe ablation may decrease inadequate treatment of large tumors and decrease recurrence rates after tumor ablation.

Animals↗
PubMed2003

Using a saline chaser to decrease contrast media in abdominal CT.

OBJECTIVE: The purpose of this study was to compare hepatic tumor conspicuity on CT after injection of either 150 mL of contrast material or 100 mL of contrast material plus a 50-mL saline chaser. SUBJECTS AND METHODS: We evaluated 86 hypoattenuating liver metastases in 26 patients. Patients underwent CT in two sessions separated by a mean of 85 days: one time with 150 mL of contrast material and the other time with 100 mL of contrast material followed by a 50-mL saline chaser. The order of the sessions was randomized. Contrast material was administered via power injector and matched for injection rate and delay time. Attenuation values were obtained from normal liver tissue and metastases and from the spleen, kidney, aorta, and inferior vena cava. RESULTS: The 150 mL dose of contrast material caused slightly greater liver and tumor attenuation than 100 mL of contrast material with a chaser (mean hepatic attenuation, 95.6 vs 89.8 H, respectively; p < 0.03, paired t test; mean tumor attenuation, 53.2 vs 49.1 H, respectively; r = 0.71, p = 0.09). The difference in conspicuity of liver lesions was slightly greater with 150 mL than with 100 mL with a chaser (46.8 H vs 44.2 H; r = 0.46, p = 0.08, paired t test), but was of doubtful clinical significance (2.6 H). Kidney, spleen, and vascular structures enhanced more with 150 mL than with 100 mL and a chaser. CONCLUSION: Using 100 mL of contrast material and a saline chaser did not result in a meaningful difference in liver parenchyma attenuation or lesion conspicuity compared with using 150 mL of contrast medium alone. Routine use of a chaser for abdominal CT may yield cost savings and a decreased risk of contrast nephropathy.

Adult↗
PubMed2003

Elastographic measurement of the area and volume of thermal lesions resulting from radiofrequency ablation: pathologic correlation.

OBJECTIVE: Elastography is a promising tool for visualizing the zone of necrosis in liver tissue resulting from radiofrequency tumor ablation. Because heat-ablated tissues are stiffer than normal untreated tissue, elastography may prove useful for following up patients who undergo radiofrequency ablative therapy. We sought to report the initial evaluations of the reliability of elastography for delineating thermal lesion boundaries in liver tissue by comparing lesion dimensions determined by elastography with the findings at whole-mount pathology. MATERIALS AND METHODS: Radiofrequency ablation was performed in vitro on liver tissue specimens encased in gelatin phantoms. The imaging plane for elastography was perpendicular to the axis of the radiofrequency electrode so that the ablated region was around the center of the plane. To obtain three-dimensional visualization of thermal lesions, we reconstructed the lesions from multiple elastograms by linearly translating the elastographic scanning plane. Pathology photographs were obtained in the same image plane used for elastography by slicing through the gelatin and tissue phantom using external markers. We used digitized gross pathology photographs obtained at a specified slice thickness to compute the areas and volumes of the lesions. These measurements were then compared to the measurements obtained from the elastograms. RESULTS: In a sample of 40 thermal lesions, we obtained a correlation between in vitro elastographic and pathologic measurements of r = 0.9371 (p < 0.00001) for area estimates and r = 0.979 (p < 0.00001) for volume estimates. CONCLUSION: We found excellent correlation between the measurements of the dimensions, areas, and volumes of thermal lesions that were based on elastographic images and the measurements that were based on digitized pathologic images. When compared with digitized pathologic measurements, elastographic measurements showed a tendency to slightly underestimate both the areas and volumes of lesions. Nevertheless, elastography is a reliable technique for delineating thermal lesions resulting from radiofrequency ablation.

Animals↗