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This study aimed to characterise the CT findings associated with hepatic and splenic melioid abscesses. Patients with CT evidence of hepatic and/or splenic abscesses were retrospectively evaluated for clinical evidence of melioidosis over a 7-year period. After blinded review of the CT characteristics of intra-abdominal abscesses (IAA), we conducted a stratified analysis of patients with and without melioid IAA. Among 49 patients with CT evidence of hepatic and/or splenic IAA, the mean age was 50.2 years, 22 (44.9%) were women and eight (16.3%) had laboratory confirmation of melioidosis. For the 113 IAA, 33 were melioid abscesses (15 liver and 18 spleen) and 80 were non-melioid abscesses (69 liver and 11 spleen). Splenic IAA were more common in the melioid group ( P = 0.001) and smaller in diameter than the hepatic IAA ( P < 0.001). Melioid IAA were smaller than non-melioid IAA ( P < 0.001) and the CT necklace sign was the strongest predictor for melioid IAA (odds ratio = 24.6, P = 0.006) with 100% specificity. Other significant predictors for melioidosis were concurrent hepatic and splenic involvement ( P = 0.009), multiple abscesses ( P = 0.015) and residence in an endemic area ( P = 0.047). By multivariate analysis, concurrent hepatic and splenic involvement was the sole predictor of melioidosis (adjusted odds ratio = 11.3, 95% confidence interval = 1.6-77.5, P = 0.014). The CT necklace sign, along with concurrent hepatic and splenic IAA, were highly suggestive of melioidosis in persons from Central Thailand. [ABSTRACT FROM AUTHOR]

Purpose: To correlate pre-ablation needle biopsy-acquired histopathologic grade of LI-RADS 5 HCC to post-ablation local tumor control rate, intrahepatic distant tumor progression-free survival, and overall survival., Materials and Methods: This single-center, retrospective cohort study included adult patients with LI-RADS 5 HCC who received a pre-ablation core needle biopsy within 3 months prior to thermal ablation from January 2015 to December 2022. Histopathologic grade from the needle biopsy was evaluated as predictor of local tumor control rate, intrahepatic distant tumor progression-free survival and overall survival. Kaplan-Meier survival curves were compared using the Gehan-Generalized Wilcoxon test., Results: The study group comprised of 133 patients (mean age, 67 +/- 10 years [SD]; 107 men) with LI-RADS 5 confirmed HCC, stratified into n=18 poorly-differentiated tumors (median follow-up 27.7 months [IQR, 15.5-55.4]) and n=115 well/moderately-differentiated tumors (median follow-up 29.2 months [IQR, 15.4-59.9]). No difference in local tumor control rate was noted between the two cohorts (HR: 1.16 [95% CI: 0.32-4.23]; p=0.898). There was significantly lower intrahepatic distant tumor progression-free survival after thermal ablation in the poorly-differentiated cohort (HR: 2.54 [0.92-7.05]; p<0.001). The overall survival in the poorly-differentiated cohort was also lower, although this did not reach statistical significance (HR: 1.77 [95% CI: 0.60-5.26]; p=0.202)., Conclusion: Patients with needle-biopsy proven poorly-differentiated LI-RADS 5 HCC have significantly lower intrahepatic distant tumor progression-free survival after thermal ablation compared to well/moderately-differentiated HCC., (Copyright © 2024. Published by Elsevier Inc.)

Purpose: To characterize the relationship between ablation zone volume (AZV) and microwave ablation (MWA) energy in an in vivo porcine liver model following arterial embolization., Materials and Methods: With Institutional Animal Care and Use Committee (IACUC) approval, 11 female swine underwent either right (n = 5) or left (n = 6) hepatic artery embolization under fluoroscopic guidance. Subsequently, ultrasound (US)-guided MWA was performed in each liver segment (left lateral, left medial, right medial, and right lateral) at either 30 W (n = 4 lobes), 60 W (n = 4), 65 W (n = 20), 90 W (n = 8), 120 W (n = 4), or 140 W (n = 4) continuously for 5 minutes. Postprocedural volumetric segmentation was performed on standardized multiphase T1 magnetic resonance (MR) imaging sequences., Results: Mean AZVs in embolized lobes (15.8 mL ± SD 10.6) were significantly larger than those in nonembolized lobes (11.2 mL ± SD 6.5, P < .01). MWA energy demonstrated significant positive linear correlation with both embolized (R 2  = 0.66, P < .01) and nonembolized (R 2  = 0.64, P < .01) lobes. The slope of the linear models corresponded to a 0.95 mL/kJ (SD ± 0.16) and 0.54 mL/kJ (SD ± 0.09) increase in ablation volume per applied kilojoule of energy (E) in embolized and nonembolized lobes, respectively. In the multivariate model, embolization status significantly modified the relationship between E and AZV as described by the following interaction term: 0.42∗E∗(embolization status) (P = .031)., Conclusions: Linear models demonstrated a near 1.8-fold increase in ratio of AZV per unit E, R(AZV:E), when applied to embolized lobes relative to nonembolized lobes. Absolute AZV differences between embolized and nonembolized lobes were greater at higher-power MWA., (Published by Elsevier Inc.)

Purpose: To assess the technical feasibility and safety of image-guided percutaneous biphasic monopolar pulsed electric field (PEF) ablation of primary and metastatic tumors., Materials and Methods: With institutional review board (IRB) approval and Health Insurance Portability and Accountability Act (HIPAA) compliance, this retrospective, single-institution study cohort of 17 patients (mean age, 53.5 years; range, 20-94 years) with overall progressive disease underwent 26 PEF ablation procedures for 30 metastatic (90%) and primary (10%) target lesions in the thorax (n = 20), abdomen (n = 7), and head and neck (n = 3). Concurrent systemic therapy was used in 14 of the 17 patients (82%). Follow-up imaging was scheduled for 1, 3, and 6 months after PEF ablation, and target and off-target lesion sizes were recorded. The overall response was assessed by the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria with imaging immediately before PEF serving as baseline. Adverse events (AEs) were determined by the Society of Interventional Radiology (SIR) classification., Results: PEF ablation procedures were well tolerated and technically feasible for all 17 patients. The mean initial sizes of the target and off-target tumors were 2.6 cm (standard deviation [SD] ± 1.5; range, 0.4-6.9 cm) and 2.2 cm (SD ± 1.1; range, 1.0-5.2 cm), respectively. Overall, 15 of the 30 (50%) target lesions and 12 of the 24 (50%) off-target lesions were unchanged or decreased in size at the patient's last follow-up. Eight patients had overall stable disease (47%) at the last follow-up. Of the 26 AEs, there were 9 mild (35%) and 1 moderate (4%) AE., Conclusions: All PEF procedures were technically feasible with 1 moderate AE and stable disease for 47% of patients with a median follow-up period of 3 months., (Copyright © 2024 SIR. Published by Elsevier Inc. All rights reserved.)

The aim of this pilot study is to evaluate and compare the quality of the genomics and proteomics data obtained from paired Formalin Fixed Paraffin Embedded (FFPE) and frozen (FF) tissue percutaneous core biopsies of Liver Imaging Reporting and Data System 5 (LIRADS 5) hepatocellular carcinoma (HCC) of varying histological grades. The preliminary data identified differentially expressed proteins and genes in poor, moderate and well differentiated HCC biopsies, with a greater efficacy in fresh frozen samples. The data offered valuable insights into the characteristics and suitability of samples for future studies., Competing Interests: Conflicts of Interest The authors declare no conflict of interest.

BACKGROUND. The classification of hepatocellular adenomas (HCAs) was updated in 2017 on the basis of genetic and molecular analysis. OBJECTIVE. The purpose of this article was to evaluate features on gadoxetate disodium-enhanced MRI of HCA subtypes on the basis of the 2017 classification and to propose a diagnostic algorithm for determining subtype using these features. METHODS. This retrospective study included 56 patients (49 women, seven men; mean age, 37 ± 13 [SD] years) with histologically confirmed HCA evaluated by gadoxetate disodium-enhanced MRI from January 2010 to January 2021. Subtypes were reclassified using 2017 criteria: hepatocyte nuclear factor-1α mutated HCA (HHCA), inflammatory HCA (IHCA), β-catenin exon 3 activated HCA (β-HCA), mixed inflammatory and β-HCA (β-IHCA), sonic hedgehog HCA (shHCA), and unclassified HCA (UHCA). Qualitative MRI features were assessed. Liver-to-lesion contrast enhancement ratios (LLCERs) were measured. Subtypes were compared, and a diagnostic algorithm was proposed. RESULTS. The analysis included 65 HCAs: 16 HHCAs, 31 IHCAs, six β-HCA, four β-IHCA, five shHCA, and three UHCAs. HHCAs showed homogeneous diffuse intralesional steatosis in 94%, whereas all other HCAs showed this finding in 0% ( p < .001). IHCAs showed the "atoll" sign in 58%, whereas all other HCAs showed this finding in 12% ( p < .001). IHCAs showed moderate T2 hyperintensity in 52%, whereas all other HCAs showed this finding in 12% ( p < .001). The β-HCAs and β-IHCAs occurred in men in 63%, whereas all other HCAs occurred in men in 4% ( p < .001). The β-HCAs and β-IHCAs had a mean size of 10.1 ± 6.8 cm, whereas all other HCAs had a mean size of 5.1 ± 2.9 cm ( p = .03). The β-HCAs and β-IHCAs showed fluid components in 60%, whereas all other HCAs showed this finding in 5% ( p < .001). Hepatobiliary phase iso- or hyperintensity was observed in 80% of β-HCAs and β-IHCAs versus 5% of all other HCAs ( p < .001). Hepatobiliary phase LLCER was positive in nine HCAs (eight β-HCAs and β-IHCAs; one IHCA). The shHCA and UHCA did not show distinguishing features. The proposed diagnostic algorithm had accuracy of 98% for HHCAs, 83% for IHCAs, and 95% for β-HCAs or β-IHCAs. CONCLUSION. Findings on gadoxetate disodium-enhanced MRI, including hepatobiliary phase characteristics, were associated with HCA subtypes using the 2017 classification. CLINICAL IMPACT. The algorithm identified common HCA subtypes with high accuracy, including those with β-catenin exon 3 mutations.

OBJECTIVE. The objective of our study was to determine the performance of 3-T multiparametric MRI (mpMRI) for prostate cancer (PCa) detection and localization, stratified by anatomic zone and level, using Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) and whole-mount histopathology (WMHP) as reference. MATERIALS AND METHODS. Multiparametric MRI examinations of 415 consecutive men were compared with thin-section WMHP results. A genitourinary radiologist and pathologist collectively determined concordance. Two radiologists assigned PI-RADSv2 scores and sector location to all detected foci by consensus. Tumor detection rates were calculated for clinical and pathologic (tumor location and zone) variables. Both rigid and adjusted sector-matching models were used to account for fixation-related issues. RESULTS. Of 863 PCa foci in 16,185 prostate sectors, the detection of overall and index PCa lesions in the midgland, base, and apex was 54.9% and 83.1%, 42.1% and 64.0% ( p = 0.04, p = 0.02), and 41.9% and 71.4% ( p = 0.001, p = 0.006), respectively. Tumor localization sensitivity was highest in the midgland compared with the base and apex using an adjusted match compared with a rigid match (index lesions, 71.3% vs 43.7%; all lesions, 70.8% vs 36.0%) and was greater in the peripheral zone (PZ) than in the transition zone. Three-Tesla mpMRI had similarly high specificity (range, 93.8-98.3%) for overall and index tumor localization when using both rigid and adjusted sector-matching approaches. CONCLUSION. For 3-T mpMRI, the highest sensitivity (83.1%) for detection of index PCa lesions was in the midgland, with 98.3% specificity. Multiparametric MRI performance for sectoral localization of PCa within the prostate was moderate and was best for index lesions in the PZ using an adjusted model.

OBJECTIVE. The purpose of this study was to compare in a multireader manner the diagnostic accuracies of 3-T multiparametric MRI interpretation and serial prostate-specific antigen (PSA) measurement in predicting the presence of residual clinically significant prostate cancer after focal laser ablation. MATERIALS AND METHODS. Eighteen men had undergone focal laser ablation for low- or intermediate-risk prostate cancer as part of two National Cancer Institute-funded phase 1 clinical trials. Multiparametric MRI was performed immediately after and 6 and 12 months after focal laser ablation. Serial PSA measurements after focal laser ablation were recorded, and MRI-ultrasound fusion biopsy was performed 6 and 12 months after ablation and served as the reference standard. Multiparametric MRI was performed at 3 T with pelvic phased-array coils. T2-weighted, DW, and dynamic contrast-enhanced MR images were retrospectively assessed by two blinded radiologists using a 3-point Likert scale (0-2). Inter-reader agreement was assessed with the Cohen kappa statistic. The diagnostic accuracies of multiparametric MRI and PSA measurement were compared. RESULTS. Residual clinically significant prostate cancer was identified in 11 of 18 (61%) men. Logistic regression analysis of serial PSA measurements yielded a correct classification rate of 61.1% ( p > 0.05). Using a multiparametric MRI threshold score of 4 or greater, both radiologists made correct classifications for 16 of 18 men (89%) at 6 months and 15 of 17 men (88%) at 12 months. Interreader agreement was substantial to excellent for T2-weighted imaging, DWI, and dynamic contrast-enhanced MRI and improved uniformly from 6 to 12 months. Logistic regression analysis of the retrospectively reviewed multiparametric MR images yielded AUCs greater than 0.90 for each radiologist 6 and 12 months after focal laser ablation ( p < 0.001). CONCLUSION. Multiparametric MRI 6 and 12 months after focal laser ablation significantly outperformed serial PSA measurements for predicting the presence of residual clinically significant prostate cancer.

OBJECTIVE. The purpose of this article is to evaluate restriction spectrum imaging (RSI) in men undergoing MRI-ultrasound fusion biopsy for suspected prostate cancer (PCa) and to compare the performance of RSI with that of conventional DWI. MATERIALS AND METHODS. One hundred ninety-eight biopsy-naïve men enrolled in a concurrent prospective clinical trial evaluating MRI-targeted prostate biopsy underwent multiparametric MRI with RSI. Clinical and imaging features were compared between men with and without clinically significant (CS) PCa (MRI-ultrasound fusion biopsy Gleason score ≥ 3 + 4). RSI z score and apparent diffusion coefficient (ADC) were correlated, and their diagnostic performances were compared. RESULTS. CS PCa was detected in 109 of 198 men (55%). Using predefined thresholds of ADC less than or equal to 1000 μm 2 /s and RSI z score greater than or equal to 3, sensitivity and specificity for CS PCa were 86% and 38%, respectively, for ADC and 61% and 70%, respectively, for RSI. In the transition zone ( n = 69), the sensitivity and specificity were 94% and 17%, respectively, for ADC and 59% and 69%, respectively, for RSI. Among lesions with CS PCa, RSI z score and ADC were significantly inversely correlated in the peripheral zone (ρ = -0.4852; p < 0.01) but not the transition zone (ρ = -0.2412; p = 0.17). Overall diagnostic accuracies of RSI and DWI were 0.70 and 0.68, respectively ( p = 0.74). CONCLUSION. RSI and DWI achieved equivalent diagnostic performance for PCa detection in a large population of men undergoing first-time prostate biopsy for suspected PCa, but RSI had superior specificity for transition zone lesions.

OBJECTIVE. The purpose of this study is to determine the overall and sector-based performance of 3-T multiparametric MRI for prostate cancer (PCa) detection and localization by using Prostate Imaging-Reporting and Data System version 2 (PI-RADSv2) scoring and segmentation compared with whole-mount histopathologic analysis. MATERIALS AND METHODS. Multiparametric 3-T MRI examinations of 415 consecutive men were compared with thin-section whole-mount histopathologic analysis. A genitourinary radiologist and pathologist collectively determined concordance. Two radiologists assigned PI-RADSv2 categories and sectoral location to all detected foci by consensus. Tumor detection rates were calculated for clinical and pathologic (Gleason score) variables. Both rigid and adjusted sector-matching models were used to account for fixation-related issues. RESULTS. The 415 patients had 863 PCa foci (52.7% had a Gleason score ≥ 7, 61.9% were ≥ 1 cm, and 90.4% (375/415) of index lesions were ≥ 1 cm) and 16,185 prostate sectors. Multiparametric MRI enabled greater detection of PCa lesions 1 cm or larger (all lesions vs index lesions, 61.6% vs 81.6%), lesions with Gleason score greater than or equal to 7 (all lesions vs index lesions, 71.4% vs 80.9%), and index lesions with both Gleason score greater than or equal to 7 and size 1 cm or larger (83.3%). Higher sensitivity was obtained for adjusted versus rigid tumor localization for all lesions (56.0% vs 28.5%), index lesions (55.4% vs 34.3%), lesions with Gleason score greater than or equal to 7 (55.7% vs 36.0%), and index lesions 1 cm or larger (56.1% vs 35.0%). Multiparametric 3-T MRI had similarly high specificity (96.0-97.9%) for overall and index tumor localization with adjusted and rigid sector-matching approaches. CONCLUSION. Using 3-T multiparametric MRI and PI-RADSv2, we achieved the highest sensitivity (83.3%) for the detection of lesions 1 cm or larger with Gleason score greater than or equal to 7. Sectoral localization of PCa within the prostate was moderate and was better with an adjusted model than with a rigid model.

Background: Multiparametric magnetic resonance imaging (mpMRI) undoubtedly affects the diagnosis and treatment of localized prostate cancer (CaP). However, clinicians need a better understanding of its accuracy and limitations in detecting individual CaP foci to optimize management., Objective: To determine the per-lesion detection rate for CaP foci by mpMRI and identify predictors of tumor detection., Design, Setting, and Participants: We carried out a retrospective analysis of a prospectively managed database correlating lesion-specific results from mpMRI co-registered with whole-mount pathology (WMP) prostatectomy specimens from June 2010 to February 2018. Participants include 588 consecutive patients with biopsy-proven CaP undergoing 3-T mpMRI before radical prostatectomy at a single tertiary institution., Outcome Measurements and Statistical Analysis: We measured mpMRI sensitivity in detecting individual CaP and clinically significant (any Gleason score ≥7) CaP foci and predictors of tumor detection using multivariate analysis., Results and Limitations: The final analysis included 1213 pathologically confirmed tumor foci in 588 patients with primarily intermediate- (75%) or high-risk (12%) CaP. mpMRI detected 45% of all lesions (95% confidence interval [CI] 42-47%), including 65% of clinically significant lesions (95% CI 61-69%) and nearly 80% of high-grade tumors. Some 74% and 31% of missed solitary and multifocal tumors, respectively, were clinically significant. The majority of missed lesions were small (61.1% ≤1cm); 28.3% were between 1 and 2cm, and 10.4% were >2cm. mpMRI missed at least one clinically significant focus in 34% of patients overall, and in 45% of men with multifocal lesions. On multivariate analysis, smaller, low-grade, multifocal, nonindex tumors with lower prostate-specific antigen density were more likely to be missed. Limitations include selection bias in a prostatectomy cohort, lack of specificity data, an imperfect co-registration process, and uncertain clinical significance for undetected lesions., Conclusions: mpMRI detects less than half of all and less than two-thirds of clinically significant CaP foci. The moderate per-lesion sensitivity and significant proportion of men with undetected tumor foci demonstrate the current limitations of mpMRI., Patient Summary: Magnetic resonance imaging of the prostate before surgical removal for prostate cancer finds less than half of all individual prostate cancer tumors. Large, solitary, aggressive tumors are more likely to be visualized on imaging., (Published by Elsevier B.V.)

Objective: The objectives of our study were to compare MR elastography (MRE) based on gradient-recalled echo (GRE) imaging with spin-echo echo-planar imaging (SEEPI) and rapid fractional (RF)-GRE MRE sequences at 3 T in terms of liver stiffness (LS) and image quality and to evaluate the effect of liver R2* on image quality., Materials and Methods: Eighty-one patients underwent 3-T liver MRE with GRE, SE-EPI, and RF-GRE sequences performed in variable order in this study. LS and ROI areas on the LS 95% confidence maps were compared among the three sequences. The relationship between liver R2* and ROI area was investigated., Results: There was no significant difference in mean LS among the three sequences (p = 0.49). Mean ROI area was significantly larger for RF-GRE (18,213 ± 9292 [SD] mm 2 ) than for GRE (13,196 ± 8149 mm 2 ) and SE-EPI (12,896 ± 8656 mm 2 ) (p < 0.0001). Liver R2* was significantly higher among patients with one or more failed sequences (mean ± SD, 116 ± 76 s -1 ) than for patients with no failed sequences (59 ± 26 s -1 ) (p = 0.001). Technical failure rates were 10% (8/81), 4% (3/81), and 2% (2/81) for GRE, SE-EPI, and RF-GRE, respectively. Among patients with iron overload (R2* ≥ 100 s -1 ), there was a trend toward larger ROI area for SE-EPI (p = 0.09)., Conclusion: SE-EPI-and RF-GRE-based MRE sequences provide equivalent measures of LS compared with GRE-based MRE, and both have lower technical failure rates. The RF-GRE sequence yielded the largest measurable area of LS. Among patients with iron overload, there was a trend toward larger measurable area of LS for the SE-EPI sequence.

Objective: The objective of our study was to determine the clinical and MRI characteristics of clinically significant prostate cancer (PCA) (Gleason score ≥ 3 + 4) in men with Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) category 3 transition zone (TZ) lesions., Materials and Methods: From 2014 to 2016, 865 men underwent prostate MRI and MRI/ultrasound (US) fusion biopsy (FB). A subset of 90 FB-naïve men with 96 PI-RADSv2 category 3 TZ lesions was identified. Patients were imaged at 3 T using a body coil. Images were assigned a PI-RADSv2 category by an experienced radiologist. Using clinical data and imaging features, we performed univariate and multivariate analyses to identify predictors of clinically significant PCA., Results: The mean patient age was 66 years, and the mean prostate-specific antigen density (PSAD) was 0.13 ng/mL 2 . PCA was detected in 34 of 96 (35%) lesions, 14 of which (15%) harbored clinically significant PCA. In univariate analysis, DWI score, prostate volume, and PSAD were significant predictors (p < 0.05) of clinically significant PCA with a suggested significance for apparent diffusion coefficient (ADC) and prostate-specific antigen value (p < 0.10). On multivariate analysis, PSAD and lesion ADC were the most important covariates. The combination of both PSAD of 0.15 ng/mL 2 or greater and an ADC value of less than 1000 mm 2 /s yielded an AUC of 0.91 for clinically significant PCA (p < 0.001). If FB had been restricted to these criteria, only 10 of 90 men would have undergone biopsy, resulting in diagnosis of clinically significant PCA in 60% with eight men (9%) misdiagnosed (false-negative)., Conclusion: The yield of FB in men with PI-RADSv2 category 3 TZ lesions for clinically significant PCA is 15% but significantly improves to 60% (AUC > 0.9) among men with PSAD of 0.15 ng/mL 2 or greater and lesion ADC value of less than 1000 mm 2 /s.

Hepatocellular carcinoma (HCC) is the main cause of mortality in patients with chronic viral hepatitis (CVH). We determined the impact of surveillance and treatments on long-term outcomes in patients with CVH who developed HCC. Between 1984 and 2014, 333 patients with HCC and with hepatitis B or hepatitis C virus infection were evaluated. An adjusted lead time bias interval was added to patients with HCC who presented with HCC (no surveillance), and their survival was compared to patients whose HCC was detected by surveillance. After HCC treatments, survival rates within and beyond 3 years of follow-up were compared. In 175 (53%) patients, HCC was detected through surveillance using alpha-fetoprotein and abdominal ultrasound examinations. Compared to 158 (47%) patients with HCC who had no surveillance, more patients with HCC detected by surveillance received surgical and locoregional treatments ( P <  0.0001 to P <  0.001), and their 1-, 3-, and 5-year overall and disease-free survival rates were significantly higher ( P <  0.001 for both). During the first 3 years of follow-up, patients with HCC receiving liver transplantation had similar survival rates as those with liver resection or radiofrequency ablation (RFA); however, due to HCC recurrence, survival in resection and RFA patients became significantly less when followed beyond 3 years ( P =  0.001 to P =  0.04). Factors associated with mortality included tumors beyond University of California at San Francisco criteria (hazard ratio [HR] 2.02; P <  0.0001), Child-Pugh class B and C (HR, 1.58-2.26; P =  0.043 to P =  0.015, respectively), alpha-fetoprotein per log ng/mL increase (HR, 1.30; P <  0.0001), previous antiviral therapy in hepatitis B virus patients (HR, 0.62; P =  0.032), and treatments other than liver transplantation (HR, 2.38-6.45; P <  0.0001 to P  < 0.003). Conclusion . Patients with HCC detected by surveillance had prolonged survival. Due to HCC recurrence, survival rates after liver resection and RFA were lower when followed beyond 3 years after treatments. ( Hepatology Communications 2017;1:595-608).

In a long-term (10-year) study of radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) as bridging therapy in patients listed for orthotopic liver transplantation (LT), we evaluated the impact of RFA on waiting list dropout rate, post-LT tumor recurrence, and long-term intention-to-treat, disease-specific survival (DSS). From March 2004 to October 2014, RFA was performed as the initial stand-alone bridge therapy to LT for 121 patients (men/women ratio, 83:38; mean age, 60.0 years) with 156 de novo HCCs (mean size, 2.4 cm). Follow-up period from initial RFA ranged from 1.3 to 128.0 months (median, 42.9 months). We assessed the overall and tumor-specific waiting list dropout rates, post-LT tumor recurrence, and 10-year post-LT and intention-to-treat survival rates. Dropout from the waiting list due to tumor progression occurred in 7.4% of patients. HCC recurrence after LT occurred in 5.6% of patients. The post-LT overall survival (OS) rate at 5 and 10 years was 75.8% and 42.2%, respectively, and the recurrence-free survival (RFS) rate was 71.1% and 39.6%, respectively. Intention-to-treat OS, RFS, and DSS rates for the entire study population at 5 and 10 years were 63.5% and 41.2%, 60.8% and 37.7%, and 89.5% and 89.5%, respectively., Conclusion: RFA as a first-line stand-alone bridge therapy to LT achieves excellent long-term overall and tumor-specific survivals, with a low dropout rate from tumor progression despite long wait list times and a sustained low tumor recurrence rate upon post-LT follow-up of up to 10 years. (Hepatology 2017;65:1979-1990)., (© 2017 by the American Association for the Study of Liver Diseases.)

Purpose: To evaluate preliminary outcomes after microwave ablation (MWA) of hepatocellular carcinoma (HCC) up to 5 cm and to determine the influence of tumor size., Materials and Methods: Electronic records were searched for HCC and MWA. Between January 2011 and September 2014, 173 HCCs up to 5 cm were treated by MWA in 129 consecutive patients (89 men, 40 women; mean age, 66.9 y ± 9.5). Tumor characteristics related to local tumor progression and primary and secondary treatment efficacy were evaluated by univariate analysis. Outcomes were compared between tumors ≤ 3 cm and tumors > 3 cm., Results: Technical success, primary efficacy, and secondary efficacy were 96.5%, 99.4%, and 94.2% at a mean follow-up period of 11.8 months ± 9.8 (range, 0.8-40.6 mo). Analysis of tumor characteristics showed no significant risk factor for local tumor progression, including subcapsular location (P = .176), tumor size (P = .402), and perivascular tumor location (P = .323). The 1-year and 2-year secondary or overall treatment efficacy rates for tumors measuring ≤ 3 cm were 91.2% and 82.1% and for tumors 3.1-5 cm were 92.3% and 83.9% (P = .773). The number of sessions to achieve secondary efficacy was higher in the larger tumor group (1.13 vs 1.06, P = .005). There were three major complications in 134 procedures (2.2%)., Conclusions: With use of current-generation MWA devices, percutaneous ablation of HCCs up to 5 cm can be achieved with high efficacy., (Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.)

Purpose: To analyze ablated tissue zones after irreversible electroporation (IRE) of porcine liver using computed tomography (CT) perfusion imaging with histopathologic correlation., Materials and Methods: Under ultrasound and CT guidance, 10 IRE ablations were performed percutaneously in three Yorkshire pigs using a single bipolar electrode. CT perfusion imaging was performed in all pigs immediately after ablation and on day 2. Pathologic sections were prepared for correlation with histopathology (hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick end labeling stains, 5-mm-thick slices). The short diameter of different enhancing zones on CT was correlated with the gross specimen., Results: CT perfusion images showed three differently enhancing zones: zone 1, inner nonenhancing zone; zone 2, middle well-defined progressive internal enhancement zone; and zone 3, outer ill-defined arterial enhancement zone with rapid washout. On histopathology, zone 1 showed a strong correlation with a pale zone, and zone 2 correlated with a red zone, together accounting for the extent of cell death. Zone 3 was outside of the ablation zone and contained inflammatory cells. Each enhancing zone had different perfusion parameters., Conclusions: CT perfusion imaging in the acute setting effectively demonstrates histopathologic tissue zones after IRE ablation. Zone 2 is unique to IRE not seen in thermal ablation, characterized by progressive intra-zonal enhancement, and its outer boundary defines the extent of cell death., (Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess radiofrequency (RF) ablation efficacy, as well as the patency of transjugular intrahepatic portosystemic shunts (TIPSs), in patients with hepatocellular carcinoma (HCC)., Materials and Methods: Retrospective database review of patients with pre-existing TIPS undergoing RF ablation of HCC was conducted over a 159-month period ending in November 2013. TIPS patency pre- and post-RF ablation was assessed by ultrasound, angiography, and/or contrast-enhanced CT or MRI. Patient demographics and immediate post-RF ablation outcomes and complications were also reviewed., Results: 19 patients with 21 lesions undergoing 25 RF ablation sessions were included. Child-Pugh class A, B, and C scores were seen in 1, 13, and 5 patients, respectively. Eleven patients (58 %) ultimately underwent liver transplantation. Immediate technical success was seen in all ablation sessions without residual tumor enhancement (100 %). No patients (0 %) suffered liver failure within 1 month of ablation. Pre-ablation TIPS patency was demonstrated in 22/25 sessions (88 %). Of 22 cases with patent TIPS prior to ablation, post-ablation patency was demonstrated in 22/22 (100 %) at immediate post-ablation imaging and in 21/22 (95 %) at last follow-up (1 patient was incidentally noted to have occlusion 31 months later). No immediate complications were observed., Conclusion: Ablation efficacy was similar to the cited literature values for patients without TIPS. Furthermore, TIPS patency was preserved in the majority of cases. Patients with both portal hypertension and HCC are not uncommonly encountered, and a pre-existing TIPS does not appear to be a definite contraindication for RF ablation.

Image-guided ablation has evolved rapidly in the past decade into a competitive technique for treating focal solid malignancies. However, as they rely mainly on thermal energy, such as radiofrequency or microwave, many tumors close to sensitive organs, such as ducts, bowel, and nerves, still remain nonablatable owing to the risk of thermal injury. Irreversible electroporation is a novel ablation modality that relies largely on a nonthermal mechanism to induce cell death, and therefore may overcome many of the shortcomings of thermal ablation. Emerging preclinical data as well as early clinical experience is showing promise for this technique in treating a variety of tumors including periportal liver masses, pancreatic cancer, perihilar renal tumors, prostate cancer, and other soft tissue tumors. However, practical limitations remain for irreversible electroporation, and its complete cancer and location-specific safety and efficacy profiles are still largely unknown. We therefore review what is known for this new ablation modality based on preclinical and preliminary clinical data, and discuss its emerging indications as well as technical challenges., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to define acute computed tomography (CT) characteristics of ablation zone created by irreversible electroporation (IRE) in porcine liver, with histopathologic correlation., Methods: Twenty-three IRE ablation zones were created in 4 Yorkshire pig livers percutaneously under image guidance. A prototype generator was used (Ethicon Endo-surgery, Cincinnati, Ohio). Variable spacing of paired electrodes between 1 and 2.0 cm was used. Contrast-enhanced multiphasic CT scans were obtained. Pigs were killed after 5 to 6 hours for gross pathology sectioning with routine and vital histological stains. Computed tomography images were analyzed using 3-dimensional software, and ablation zone size measured on CT was correlated with pathologically determined size., Results: Nineteen of 19 ablation zones created with up to 1.5-cm spacing showed fusion between individual ablation zones generated by each electrode. Ablation zones were isodense precontrast and hypodense to liver postcontrast, with best delineation in the portal phase. Nine of these had nondistorted circumferential margins on both CT and gross pathology suitable for correlation, and among these, size measurements on CT were closely correlated with pathologically determined ablation zone size. Most importantly, on the delayed venous phase, there is internal enhancement within the ablation zone itself, except for small perielectrode zones that remained hypodense. On histopathology, IRE ablation zones showed preserved microvasculature with congestion of sinusoids, except for small perielectrode zones where coagulative changes were suggested., Conclusion: Portal phase contrast-enhanced CT scans correlate well with liver IRE ablation size and shape on histopathology.

Objective: The objective of the study was to determine the short- and long-term effects of irreversible electroporation (IRE) on the hepatic veins and the perivascular tissue through serial computed tomography (CT) with pathological correlation., Materials and Methods: Multiple IRE lesions were created percutaneously by ultrasound guidance in livers of 11 Yorkshire pigs using a prototype IRE generator. Paired electrodes were used. Three pigs were killed at the same day; 2 pigs, at 2 days; 2 pigs, at 2 weeks; 2 pigs, at 4 weeks; and 2 pigs, at 8 weeks. Contrast-enhanced CT was performed in all pigs initially and thereafter at selected intervals. Pathological sections were performed for correlation. Initial CT scans were analyzed for lesions for degree of circumferential contact (< 25%, 26%-50%, 51%-75%, and 76%-100%) to the hepatic veins for analysis of any contour deformity. The hepatic veins were also analyzed for any thrombus and for any narrowing. Those lesions with follow-up scans were also analyzed for changes over time., Results: Twenty-three lesions showed contiguity to the hepatic veins between 3 to 9 mm in size at the initial CT. No contour deformity due to perivascular tissue sparing is detected for any lesion. There was no thrombus detected in any vessel at any time point. Vessel narrowing was seen in 9 of 23 veins on the initial CT, all less than 50% in diameter and all with lesion contact of greater than 25% in circumference, but 2 of 3 veins with follow-up scans showed return-to-normal caliber. No late narrowing of any hepatic vein was seen on the long-term follow-up., Conclusion: Irreversible electroporation creates uniform tissue ablation around the hepatic veins without perivascular tissue sparing. Vessel narrowing may occur acutely but without long-term sequela.

Objective: The objective of our study was to evaluate the performance of liver CT in the diagnosis of esophageal varices in patients with cirrhosis and to determine whether thin-section multiplanar reconstructions (MPRs) improve accuracy., Materials and Methods: We identified 109 patients with cirrhosis who underwent endoscopy within 10 weeks after dual-phase liver MDCT supplemented with thin-section axial and coronal portal venous phase reconstructions. Two blinded radiologists independently evaluated each CT examination for the presence and sizes of varices using standard 5-mm axial versus 1- to 3-mm multiplanar images in separate sessions. Sensitivity, specificity, and predictive value calculations and receiver operating characteristic analysis were performed using endoscopy as the reference standard. Interobserver variability and correlation of CT size to variceal grade were assessed., Results: Twenty-six cases of high-risk esophageal varices were identified; all except two were detected on CT by one of the readers on standard 5-mm images. For both readers, sensitivity and negative predictive value (NPV) for the discrimination of high-risk varices using a criterion of 2 mm or greater were nearly the same for the standard 5-mm images versus the 1- to 3-mm multiplanar images (sensitivity and NPV: reader 1, 96% and 98% vs 96% and 99%; reader 2, and 89% and 95% vs 89% and 96%, respectively). Standard 5-mm images yielded a lower specificity for high-risk esophageal varices than the thin-section multiplanar images, and this difference was statistically significant for reader 2. Substantial interobserver agreement was noted for both esophageal varices detection and size measurements., Conclusion: Standard liver CT is sensitive for the detection of high-risk varices and deserves further investigation as a potential cost-effective screening tool for the evaluation of patients with cirrhosis. The addition of 1- to 3-mm MPRs may increase specificity for risk stratification based on size measurements.

Background & Aims: In patients with cirrhosis, hepatocellular carcinoma (HCC) is detected by ultrasound (US), computed tomography (CT), or magnetic resonance imaging (MRI); US is recommended for screening and surveillance. We performed a retrospective analysis of the abilities of these cross-sectional imaging modalities to detect HCC., Methods: We analyzed data from 638 consecutive adult patients with cirrhosis who received liver transplants within 6 months of imaging at a tertiary care institution. Imaging reports and serum alpha-fetoprotein levels were compared with results from pathology analysis of explants as the reference standard. Sensitivities of US, CT, and MRI were calculated overall and in defined size categories. False-positive imaging results and patient-based specificities were evaluated., Results: Of the 638 patients, 225 (35%) had HCC, confirmed by pathology analysis of liver explants. In 23 cases, the lesions were infiltrative or extensively multifocal. In the remaining 202 explants (337 numerable, discrete nodules), respective lesion-based sensitivities of US, CT, and MRI were 46%, 65%, and 72% overall and 21%, 40%, and 47% for small (<2 cm) HCC. The sensitivity of US increased with the availability of CT or MRI data (P = .049); sensitivity values were 62% and 85% for lesions 2-4 and ≥ 4 cm, respectively. Patient-based specificities of US, CT, and MRI were 96%, 96%, and 87%, respectively., Conclusions: US, CT, and MRI did not detect small HCC lesions with high levels of sensitivity, although CT and MRI provide substantial improvements over unenhanced US in patients with cirrhosis who received liver transplants., (Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Objective: To assess the utility of CT angiography (CTA) in preoperative mapping of hepatic vascular anatomy in adult-to-adult living related liver transplant (LRLT) donors., Material and Method: Over a 3-year period, 32 potential LRLTdonors underwent CTA with subsequent comparison studies [digital subtraction angiography (DSA) and/or transplantation] were included in this study. Their CTA reports were retrospectively correlated with available DSA and/or operative findings., Results: CTA correctly predicted right lobe arterial and portal venous anatomy in 32/32 (100%) donors. In 27 donors, hepatic venous anatomy on CT was compared with operative findings. The hepatic veins were well opacified in 23/27 (85.2%) donors. Of these, 15/16 (93.8%) significant (> or =5 mm) accessory right hepatic veins and 11/11 (100%) significant segment VIII vein draining to middle hepatic vein were detected., Conclusion: CTA provided an excellent preoperative depiction of hepatic vascular anatomy in LRLT donors.

Objective: To evaluate the performance of multidetector computed tomographic angiography (MDCTA) in assessing the surgical resectability of pancreatic head adenocarcinoma., Methods: With institutional review board approval, radiographic, surgical, and pathological records of 203 consecutive patients with adenocarcinoma of the pancreatic head were analyzed retrospectively. Patients were imaged with MDCT scanners using our institution's CTA pancreatic protocol. Images were compared with surgical outcomes to determine the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCTA in determining resectability., Results: Data were analyzed twice, once with equivocal findings on MDCTA assumed as resectable and again with equivocal cases assumed as unresectable. All equivocal cases were ultimately unresectable; when this was assumed, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were determined to be 100%, 71%, 85%,100% and 89%. Twelve patients deemed resectable by preoperative MDCTA were found to be unresectable on surgical exploration owing to vascular involvement (n = 4), liver metastases (n = 4), and peritoneal involvement (n = 4)., Conclusions: Multidetector CT angiography offers accurate and valuable preoperative assessment of surgical resectability of pancreatic ductal adenocarcinoma. Liver and peritoneal metastases and vascular invasion still remain important pitfalls in preoperative evaluation.

Objectives: To analyze all cases of nephrogenic systemic fibrosis (NSF) at our institution and to compare them with controls., Methods: After the institutional review board approval, 13 biopsy-proven NSF cases were identified. Ten cases had complete records and were compared in a case-control format with 10 age- and sex-matched, dialysis-dependent controls. Analyzed risk factors included single and cumulative gadolinium dose, medication and transplant history, and serum electrolytes at the time of gadolinium exposure., Results: There were 1.9% of dialysis-dependent, gadolinium-exposed patients who developed NSF. There was no difference in gadolinium dose, transplant history, or serum electrolytes. Seven of 10 cases and 3 of 10 controls were treated with erythropoietin (P = 0.13). At the time of NSF diagnosis, 7 of 10 cases were on immunosuppressive therapy. Two of 7 cases developed NSF only after immunosuppressive therapy was initiated. Two of 10 controls were on immunosuppressive therapy (P = 0.06)., Conclusions: All cases of NSF occurred in dialysis-dependent, gadolinium-exposed patients. Associations between immunosuppressive and erythropoietin therapies and NSF need further investigation.

Imaging studies play a crucial role in the diagnosis and management of patients with pancreatic adenocarcinoma. Computed tomography (CT) is the most widely available and best-validated modality for imaging patients with pancreatic adenocarcinoma. To maximize the diagnostic efficacy of CT, use of a pancreas protocol is mandatory. The sensitivity of CT for diagnosis of pancreatic adenocarcinoma (89%-97%) and its positive predictive value for predicting unresectability (89%-100%) are high. The positive predictive value of CT for predicting resectability (45%-79%) is low because the diagnostic criteria for diagnosing vascular invasion by tumor favors specificity over sensitivity to avoid denying surgery to patients with potentially resectable tumor. Furthermore, the sensitivity of CT for small hepatic and peritoneal metastases is limited. Magnetic resonance imaging has not been shown to perform better than CT for the diagnosis and staging of pancreatic adenocarcinoma, but can be helpful as an adjunct to CT, particularly for evaluation of small hepatic lesions that cannot be fully characterized by CT. Ultrasound is often the first study obtained in patients with obstructive jaundice or unexplained abdominal pain, but its utility for diagnosis and staging of patients with pancreatic adenocarcinoma is limited. Positron emission tomography/CT combines the functional information provided by positron emission tomography with the anatomic information provided by CT and is a promising modality for imaging of patients with pancreatic adenocarcinoma, but its utility has not been established. Endoscopic ultrasound is generally considered superior to CT for the diagnosis and local staging of pancreatic cancer, but is limited by availability and inability to assess for distant metastases.

Objective: To determine the frequency of typical features of pancreatic cystic lesions on high-resolution computed tomography and the combination of features that best influences discrimination., Methods: Ten computed tomography features of 100 proven pancreatic cystic lesions were retrospectively tabulated by 2 blinded imagers. After final diagnosis was revealed, each lesion was categorized as typical or atypical. Stepwise multivariable logistic regression was used to determine which of 10 imaging and 4 clinical features significantly distinguished between benign and malignant lesions., Results: There were 38 benign cysts and 62 cystic tumors. Serous lesions presented with greater than 6 cysts (83%) and cysts of less than 2 cm (44%). Mucinous lesions presented with cysts of 2 cm or greater (82%) and less than 6 cysts (64%). Pseudocysts, serous, and mucinous lesions presented typically in 77%, 67%, and 64% of cases, respectively. The significant variables in classifying malignant lesions are pancreatitis history, cyst size, symptoms, and calcification pattern (area under the curve, 0.837)., Conclusions: Four specific imaging and clinical features in combination best predict a malignant lesion.

Purpose: To determine influence of hepatic vein size on perfusion-mediated attenuation in adjacent microwave thermal ablation., Materials and Methods: With approval of the institutional animal research committee, seven Yorkshire pigs underwent percutaneous (n = 2) or open (n = 5) microwave liver ablation under general anesthesia. In each, multiple ultrasound-guided, nonoverlapping thermal lesions were created within 1 cm of hepatic veins in a 5-10-minute ablation at 45 W. After euthanasia, the liver was harvested and sectioned at 0.5-cm intervals and the degree of perivascular coagulation attenuation was graded on histopathologic analysis. Correlation between venous size (small, < or =3 mm; medium, 3-6 mm; and large, >6 mm) and attenuation grade was performed with use of the Spearman rank test., Results: In 63 of 103 sections (61%)--29 of 37 (78%) small, 27 of 48 (56%) medium, and seven of 18 (39%) large veins--the thermal injury extended to the vein wall around the entire circumference of the coagulation front without distortion of the ablation margin. In 40 of 103 sections (38.9%), varying degrees of concave distortion of perivenous ablation margins were noted, with significant correlation between vein size and heat-sink extent (P < .01). However, thermal injury extended to the vascular wall in all sections without complete circumferential sparing of liver tissue. Around two thrombosed veins, thermal lesions encased the vessels, producing paradoxically convex ablation margins., Conclusions: Although the heat-sink effect was significantly dependent on hepatic vein size, the majority of pathologic sections exhibited no or minimal effect. Further study is required to assess clinical implications.

Objective: Our purpose was to retrospectively evaluate percutaneous radiofrequency ablation of unifocal subcapsular hepatocellular carcinoma (HCC) in comparison with nonsubcapsular tumors with regard to the technical and clinical outcomes., Materials and Methods: A total of 42 patients (23 men and 18 women; age range, 22-83 years) with unifocal HCC underwent percutaneous radiofrequency ablation as their sole interventional treatment between May 1998 and August 2003. Subcapsular tumors were selected for ablation if there was no large exophytic component, and they were ablated through an indirect puncture, a gradual increase in radiofrequency power output, and needle track ablation. Technical effectiveness after single-session radiofrequency ablation, complications, local tumor progression, overall survival, and event-free survival rates were compared between the two groups., Results: There were 15 patients with subcapsular HCC and 27 patients with nonsubcapsular HCC. The technical effectiveness was 93% (14/15) in the subcapsular HCC group and 96% (26/27) in the nonsubcapsular group (p > 0.99), complication rates were 0% (0/15) and 7.4% (2/27) (p = 0.53), and rates of local tumor progression were 21% (3/14) and 15% (4/26) (p = 0.68), respectively. No needle track or peritoneal seeding was found in either group. No significant differences were found in overall survival (3 years: 60% vs 56%; p = 0.78) and event-free survival rates (3 years: 59% vs 48%; p > 0.99) between the two groups., Conclusion: Radiofrequency ablation of subcapsular HCC can be comparable to that of nonsubcapsular HCC with regard to the technical and clinical outcomes when there is proper patient selection and an optimized technique is used.

Objective: To determine the accuracy of high-resolution computed tomography in discriminating among pancreatic cystic lesions with and without clinical history., Methods: Multiphasic high-resolution computed tomographic scans of 100 proven cystic pancreatic lesions were retrospectively reviewed by 2 blinded imagers. Before and after a history of pancreatitis was revealed, readers classified lesions as either nontumor-related or tumor-related. Reviewers also classified lesions as benign or malignant and finally categorized each lesion as serous, mucinous, or other lesion. Diagnostic performance parameters for classification were calculated for each reader with and without history., Results: Sixty-two lesions were tumor-related and 38 were not. Accuracy for classifying tumor-related from unrelated cysts for both reviewers increased (83%-92%, 85%-91%) when unblinded to pancreatitis history. Specificity also significantly increased (66%-88% and 84%) for both reviewers., Conclusions: Pancreatic-phase computed tomography enabled more than 80% accuracy in discriminating between tumor-related and unrelated lesions and increased with information of pancreatitis history.

Hepatic lymphangiomatosis is a rare disease characterized by an abnormal lymphatic proliferation involving the liver alone, liver and spleen, or multiple organs. Hepatic lymphangiomatosis becomes symptomatic secondary to compression or replacement of the normal parenchyma, which can lead to liver failure. Resection and orthotopic liver transplantation (OLT) can be used as treatment for this disease. We herein describe a 42-year-old female who had undergone successful OLT for hepatic lymphangiomatosis with recurrent disease detected 19 yr later in the transplanted liver. This is, to our knowledge, the first described case of recurrent hepatic lymphangiomatosis after OLT. In conclusion, we discuss the clinical, radiologic, pathologic, and immunohistochemical findings and review other reported cases of hepatic lymphangiomatosis that have undergone OLT., ((c) 2007 AASLD.)

Objective: Using 16-MDCT, we describe and quantify the frequency and types of renal anatomic variants and findings relevant for preoperative evaluation and surgical planning for potential laparoscopic renal donors., Materials and Methods: On 16-MDCT, 126 consecutive potential donors underwent scanning before contrast administration and after i.v. power injection of nonionic contrast material during the arterial, nephrographic, and excretory phases. On a 3D workstation, CT images were evaluated retrospectively in consensus by three abdominal imagers. The number and branching pattern of bilateral renal arteries and veins, including anomalies of the inferior vena cava and lumbar-gonadal axis, were categorized along with the frequency of incidental findings of the renal parenchyma and collecting system., Results: Major arterial variants including supernumerary and early branching arteries were present in 16% and 21%, respectively, of left kidneys and 22% and 15%, respectively, of right kidneys. Major and minor venous variants were detected in 11% and 58% of left kidneys and 24% and 3% of right kidneys. Late confluence of the venous trunk was identified in 17% of left kidneys and 10% of right kidneys. Incidental parenchymal and urothelial abnormalities, most commonly cysts and calyceal calcifications, were identified in 30% of the kidneys. Other relevant incidental findings included focal infarcts, cortical scars, atrophic scarred kidney, and bilateral papillary necrosis. Urothelial variants included bilateral simple ureteroceles and rightsided complete duplicated collecting system., Conclusion: 16-MDCT angiography and urography allow confident detection and classification of a variety of anatomic and incidental anomalies relevant to the preoperative selection of potential laparoscopic renal donors and to surgical planning.

Objective: The objective of this study was to evaluate the performance of routine helical liver CT in the detection and grading of esophageal varices in cirrhotic patients., Materials and Methods: A total of 67 consecutive cirrhotic patients who underwent both upper endoscopy and helical liver CT within a 4-week interval were evaluated. The CT protocol included unenhanced, arterial, and portal phases with a collimation of 7-7.5 mm. Two blinded abdominal imagers (6 and 7 years' experience) retrospectively interpreted all CT images to detect the presence of esophageal varices on a 5-point confidence scale and measure the largest varix identified. Receiver operating characteristic (ROC) curve analysis was performed, and the correlation between CT measurements and endoscopic grading, the reference standard, was assessed., Results: The variceal detection rates for the observers was 92% (11/12) and 92% (11/12) for large (i.e., clinically significant) varices, 53% (16/30) and 60% (18/30) for small varices, and 64% (27/42) and 69% (29/42) for all varices. The area under the ROC curve for the detection of esophageal varices of any size was 0.77 (observer 1) and 0.80 (observer 2). CT variceal grading showed a strong correlation with endoscopic grading for both observers (p < or = 0.001). Using a variceal diameter threshold of 3 mm on CT, sensitivity, specificity, and accuracy for distinguishing large esophageal varices from small or no varices were 92% (11/12), 84% (46/55), and 85% (57/67), respectively, for both observers., Conclusion: Liver CT is useful for the detection and grading of esophageal varices. A diameter of 3 mm may be an appropriate screening threshold for large clinically significant varices.

Objective: Microwave ablation is emerging as a new treatment option for patients with unresectable hepatic malignancies. This two-center study shows the results of a phase 1 clinical trial of patients with known hepatic masses who underwent synchronous triple antenna microwave ablation before elective hepatic resection., Subjects and Methods: Intraoperative microwave ablation was performed before hepatic resection. Hepatic lesions were targeted using real-time intraoperative sonography with three microwave antennas positioned in a triangular configuration. Microwave ablation was performed at 45 W for 10 minutes. Hepatic resection was then completed in the standard fashion. Gross specimens were sectioned and measured to determine tumor and ablation sizes. Representative areas were stained with H and E stain and vital histochemical nicotinamide adenine dinucleotide (NADH) stain., Results: Ten patients with a mean age of 64 years (range, 48-79 years) were treated. Tumor histology included colorectal carcinoma metastases and hepatocellular carcinoma. The mean maximal tumor diameter was 4.4 cm (range, 2.0-5.7 cm). The mean maximal ablation diameter was 5.5 cm (range, 5.0-6.5 cm), while the average ablation zone volume was 50.8 cm3 (range, 30.3-65.5 cm3). Gross and microscopic examinations of areas after microwave ablation showed clear coagulation necrosis, even surrounding large hepatic vessels (> 3 mm in diameter). A marked thermallike effect was observed with maximal intensity closest to the antenna sites. NADH staining confirmed the uniform absence of viable tumor in the ablation zone., Conclusion: This study shows the feasibility of using multiple microwave antennas simultaneously in the treatment of liver tumors intraoperatively. Additional percutaneous studies are currently under way to investigate the safety and efficacy in treating nonsurgical candidates.

Objective: Our objective was to determine the efficacy of 16-MDCT angiography in preoperative evaluation of vascular anatomy of laparoscopic renal donors., Methods and Materials: Fifty-five consecutive renal donors (25 men and 30 women) underwent 16-MDCT angiography followed by donor nephrectomy. In the arterial and nephrographic phases, images were acquired with 60% overlap and 0.6-mm reconstruction in both phases after 120 mL of iohexol was injected at 4 mL/sec. On a 3D workstation, images were evaluated retrospectively by two abdominal imagers blinded to surgical results with respect to number and branching pattern of renal arteries and major and minor renal veins. These CT angiography results were compared with surgical findings., Results: The surgically confirmed sensitivity of both reviewers (1 and 2) using the MDCT data for detection of renal arteries was 98.5% (65 of 66), and accuracies were 97.0% for reviewer 1 and 95.5% for reviewer 2. Sensitivity and accuracy detection of renal veins was 97% (61 of 63) and 98% (62 of 63) for reviewer 1 and reviewer 2, respectively. Sensitivity and accuracy detection of early arterial bifurcation (< 2 cm from aorta) was 100% (14 of 14), and sensitivity in detection of late venous confluence (< 1.5 cm from aorta) was 100% (8 of 8). All major renal venous variants were identified; reviewer 1 identified 78% (18 of 23) minor venous variants, and reviewer 2 identified 83% (19 of 23) minor venous variants. There were no hemorrhagic complications at surgery. Excellent agreement between reviewers (kappa = 0.92-0.97) was achieved for detection of normal and variant anatomy., Conclusion: 16-MDCT angiography enabled excellent preoperative detection of arterial anatomy and venous laparoscopic donor nephrectomy.

The purpose of this work is to describe our experience with single-session percutaneous ethanol injection (PEI) under the guidance of 0.2-T open MRI for hepatocellular carcinomas (HCC) that were not suitable for ablation under ultrasound (US) or computed tomography (CT) guidance. None of the lesions (N = 7) were detectable on US. MRI was chosen over CT as the guidance modality because the nodules were located in the hepatic dome (N = 4) or were invisible on noncontrast CT (N = 3). All of the nodules were targeted successfully, and apparently complete tumor necrosis was achieved in six nodules (86%). During a follow-up of one to 41 months, only one patient developed local recurrence four months after PEI. MR-guided PEI is feasible and effective for treating HCC when other imaging guidance methods are not appropriate., ((c) 2005 Wiley-Liss, Inc.)

A variety of anatomic variants and pathologic conditions in and around the pancreas may simulate primary pancreatic neoplasia at routine abdominal cross-sectional imaging. An ambiguous lesion whose appearance suggests a pancreatic origin requires a broad differential diagnosis that can subsequently be narrowed on the basis of both clinical history and features at optimal computed tomography (CT) and magnetic resonance (MR) imaging. Pancreas-specific multidetector CT and MR imaging techniques with thin collimation, multiplanar and multiphasic scans, and newly introduced curved planar reformation may help avoid potential diagnostic pitfalls. These techniques can help identify and characterize a mass in multiple viewing planes, thereby helping distinguish a true pancreatic neoplasm from peripancreatic adenopathy or from a tumor of the adjacent duodenum or small bowel. They can also help determine the cause of a tumor. It is important that the radiologist be familiar with the wide spectrum of anatomic variants and disease entities that can mimic primary pancreatic neoplasia in order to initiate the appropriate lesion-specific work-up and treatment and avoid unnecessary tests or procedures, including surgery.

Objective: The objective of our study was to compare a breath-hold fat-suppressed fast-recovery fast spin-echo (FSE) T2-weighted sequence with a respiratory-triggered fat-suppressed FSE T2-weighted sequence to assess the effect on image quality and lesion detection and characterization in clinical hepatic imaging., Materials and Methods: Both the breath-hold fat-suppressed fast-recovery FSE and respiratory-triggered fat-suppressed FSE T2-weighted sequences were acquired in 46 patients. Two radiologists, blinded to clinical data, independently evaluated randomized images from both sequences. Qualitatively, images were graded on a 5-point scale for five different characteristics. The number and location of lesions were recorded. The confidence of detection and the confidence of characterization (solid vs nonsolid) were graded on a 5-point scale. A consensus review using radiology, clinical, and pathology data served as the standard. Receiver operating characteristic (ROC) curve analysis (area under the ROC curve [A(z)]) was used to compare each reviewer's interpretation against the consensus interpretation. Quantitative analysis was performed by calculating the liver signal-to-noise ratio (SNR), liver-to-spleen contrast-to-noise ratio (CNR), and lesion-to-liver CNR. Both one- and two-tailed Student's t tests were used to check for significance., Results: Qualitatively, both reviewers graded the breath-hold fat-suppressed fast-recovery FSE T2-weighted sequence better than the respiratory-triggered fat-suppressed FSE T2-weighted sequence on all five characteristics (p < 0.005). Of 78 lesions detected, 29 were characterized as solid; 47, nonsolid; and two, indeterminate. On ROC analysis, there were no significant differences between the breath-hold fat-suppressed fast-recovery FSE and respiratory-triggered fat-suppressed FSE T2-weighted sequences in lesion detection (A(z) reviewer 1, 0.77 and 0.83, respectively, [p = 0.12]; A(z) reviewer 2, 0.84 and 0.80, respectively [p = 0.12]) or in lesion characterization (A(z) reviewer 1, 0.86 and 0.92, respectively [p = 0.33]; A(z) reviewer 2, 0.90 and 0.91, respectively [p = 0.79]). Quantitatively, liver SNRs, spleen CNRs, and lesion CNRs (solid and nonsolid lesions) were significantly better on the breath-hold fat-suppressed fast-recovery FSE T2-weighted images than on the respiratory-triggered fat-suppressed FSE T2-weighted images (p < 0.005)., Conclusion: Breath-hold fat-suppressed fast-recovery FSE T2-weighted images were of better quality than respiratory-triggered fat-suppressed FSE T2-weighted images, and lesion detection and characterization were comparable.

Purpose: To compare the performance of dynamic gadolinium-enhanced and ferumoxides-enhanced MRI in the detection and characterization of hepatic lesions, on 1.5-T and 0.2-T magnets, Materials and Methods: In 41 patients (23 men, 18 women), 52 hepatic MR examinations were performed and retrospectively analyzed; 39 and 13 examinations were performed on 1.5-T and 0.2-T magnets, respectively. A total of 33 of 41 patients had known malignancies, and 31 of 33 patients had biopsy of at least one lesion. First, a combination of unenhanced T2-weighted sequences and gradient-echo T1-weighted sequences were performed. Then, dynamic gadolinium-enhanced (0.1 mmol/kg) T1 GRE sequences were obtained, followed by intravenous drip infusion of ferumoxides (10 micromol/kg). The T2-weighted sequences were then repeated. The unenhanced and gadolinium-enhanced images (the Gd set) were reviewed separately from the unenhanced and ferumoxides-enhanced images (the ferumoxides set) by two abdominal imagers. The reviewers were blinded to clinical history and reviewed the individual studies in each set randomly. Each detected lesion was scored on a five-point scale for characterization scores: nonsolid (1 or 2), indeterminate (3), or solid (4 or 5). A consensus review was then performed correlating all available pathology, imaging, clinical findings, and follow-up to act as a gold standard. Receiver-operating-characteristic (ROC) curves were generated and both area-under-the-curve (Az values) and sensitivity values were calculated. Significance of Az and sensitivity differences was assessed using standard Z-test and chi-square., Results: Of 270 lesions detected by consensus, 211 were on 1.5-T and 59 were on 0.2-T scanners. The accuracy (Az values) of lesion detection overall, of both readers, was greater for the ferumoxides set than for the Gd set (reader 1: 0.95 vs. 0.89 (P < 0.05); reader 2: 0.91 vs. 0.78 (P < 0.05)). Az values for both readers were greater on the ferumoxides set for both the 1.5-T scans and the 0.2-T scans. Out of 270 lesions detected, 231 were characterized by consensus review as solid (185) or nonsolid (46). There was a significant improvement in lesion characterization for both readers on the GD set compared with the ferumoxides set on both high and low field scanners (Az reader 1: 0.99 vs. 0.96 (P < 0.05); Az reader 2: 0.99 vs. 0.95 (P < 0.05)), respectively., Conclusion: At both 1.5-T and 0.2-T, ferumoxides-enhanced sequences were better for lesion detection, while gadolinium-enhanced sequences were better for lesion characterization, respectively., (Copyright 2004 Wiley-Liss, Inc.)