Automated Assessment of T2-Weighted MRI to Differentiate Malignant and Benign Primary Solid Liver Lesions in Noncirrhotic Livers Using Radiomics.

RATIONALE AND OBJECTIVES: Distinguishing malignant from benign liver lesions based on magnetic resonance imaging (MRI) is an important but often challenging task, especially in noncirrhotic livers. We developed and externally validated a radiomics model to quantitatively assess T2-weighted MRI to distinguish the most common malignant and benign primary solid liver lesions in noncirrhotic livers. MATERIALS AND METHODS: Data sets were retrospectively collected from three tertiary referral centers (A, B, and C) between 2002 and 2018. Patients with malignant (hepatocellular carcinoma and intrahepatic cholangiocarcinoma) and benign (hepatocellular adenoma and focal nodular hyperplasia) lesions were included. A radiomics model based on T2-weighted MRI was developed in data set A using a combination of machine learning approaches. The model was internally evaluated on data set A through cross-validation, externally validated on data sets B and C, and compared to visual scoring of two experienced abdominal radiologists on data set C. RESULTS: The overall data set included 486 patients (A: 187, B: 98, and C: 201). The radiomics model had a mean area under the curve (AUC) of 0.78 upon internal validation on data set A and a similar AUC in external validation (B: 0.74 and C: 0.76). In data set C, the two radiologists showed moderate agreement (Cohen's κ: 0.61) and achieved AUCs of 0.86 and 0.82. CONCLUSION: Our T2-weighted MRI radiomics model shows potential for distinguishing malignant from benign primary solid liver lesions. External validation indicated that the model is generalizable despite substantial MRI acquisition protocol differences. Pending further optimization and generalization, this model may aid radiologists in improving the diagnostic workup of patients with liver lesions.

Consensus report from the 10th Global Forum for Liver Magnetic Resonance Imaging: developments in HCC management.

The 10th Global Forum for Liver Magnetic Resonance Imaging (MRI) was held as a virtual 2-day meeting in October 2021, attended by delegates from North and South America, Asia, Australia, and Europe. Most delegates were radiologists with experience in liver MRI, with representation also from specialists in liver surgery, oncology, and hepatology. Presentations, discussions, and working groups at the Forum focused on the following themes: • Gadoxetic acid in clinical practice: Eastern and Western perspectives on current uses and challenges in hepatocellular carcinoma (HCC) screening/surveillance, diagnosis, and management • Economics and outcomes of HCC imaging • Radiomics, artificial intelligence (AI) and deep learning (DL) applications of MRI in HCC. These themes are the subject of the current manuscript. A second manuscript discusses multidisciplinary tumor board perspectives: how to approach early-, mid-, and late-stage HCC management from the perspectives of a liver surgeon, interventional radiologist, and oncologist (Taouli et al, 2023). Delegates voted on consensus statements that were developed by working groups on these meeting themes. A consensus was considered to be reached if at least 80% of the voting delegates agreed on the statements. CLINICAL RELEVANCE STATEMENT: This review highlights the clinical applications of gadoxetic acid-enhanced MRI for liver cancer screening and diagnosis, as well as its cost-effectiveness and the applications of radiomics and AI in patients with liver cancer. KEY POINTS: • Interpretation of gadoxetic acid-enhanced MRI differs slightly between Eastern and Western guidelines, reflecting different regional requirements for sensitivity vs specificity. • Emerging data are encouraging for the cost-effectiveness of gadoxetic acid-enhanced MRI in HCC screening and diagnosis, but more studies are required. • Radiomics and artificial intelligence are likely, in the future, to contribute to the detection, staging, assessment of treatment response and prediction of prognosis of HCC-reducing the burden on radiologists and other specialists and supporting timely and targeted treatment for patients.

Impact of COVID-19 on the management of hepatocellular carcinoma in a high-prevalence area: What's new 12 months later?

INTRODUCTION AND OBJECTIVES: The lockdown policy introduced in 2020 to minimize the spread of the COVID-19 pandemic, significantly affected the management and care of patients affected by hepatocellular carcinoma (HCC). The aim of this follow-up study was to determine the 12 months impact of the COVID-19 pandemic on the cohort of patients affected by HCC during the lockdown, within six French academic referral centers in the metropolitan area of Paris. MATERIALS AND METHODS: We performed a 12 months follow-up of the cross-sectional study cohort included in 2020 on the management of patients affected by HCC during the first six weeks of the COVID-19 pandemic (exposed), compared to the same period in 2019 (unexposed). Overall survival were compared between the groups. Predictors of mortality were analysed with Cox regression. RESULTS: From the initial cohort, 575 patients were included (n = 263 Exposed_COVID, n = 312 Unexposed_COVID). Overall and disease free survival at 12 months were 59.9 ± 3.2% vs 74.3 ± 2.5% (p<0.001) and 40.2 ± 3.5% vs 63.5 ± 3.1% (p<0.001) according to the period of exposure (Exposed_COVID vs Unexposed_COVID, respectively). Adjusted Cox regression revealed that the period of exposure (Exposed_COVID HR: 1.79, 95%CI (1.36, 2.35) p<0.001) and BCLC stage B, C and D (BCLC B HR: 1.82, 95%CI (1.07, 3.08) p = 0.027 - BCLC C HR: 1.96, 95%CI (1.14, 3.38) p = 0.015 - BCLC D HR: 3.21, 95%CI (1.76, 5.85) p<0.001) were predictors of death. CONCLUSIONS: Disruption of routine healthcare services because of the pandemic translated to reduced 1 year overall and disease-free survival among patients affected by HCC, in the metropolitan area of Paris, France.

Impact of Extended Use of Ablation Techniques in Cirrhotic Patients with Hepatocellular Carcinoma: A Cost-Effectiveness Analysis.

BACKGROUND: To evaluate the cost-effectiveness of the extended use of ablation for the treatment of hepatocellular carcinoma (HCC) with cirrhosis in an expert ablation center when compared to the non-extended use of ablation in equivalent tertiary care centers. METHODS: Consecutive cirrhotic patients with non-metastatic HCC, no prior treatment, and referred to three tertiary care centers between 2012 and 2016 were retrospectively identified. The Bondy group, including all of the patients treated at Jean Verdier Hospital, where the extended use of ablation is routinely performed, was compared to the standard of care (SOC) group, including all of the patients treated at the Beaujon and Mondor Hospitals, using propensity score matching. A cost-effectiveness analysis was carried out from the perspective of French health insurance using a Markov model on a lifetime horizon. RESULTS: 532 patients were matched. The Bondy group led to incremental discounted lifetime effects of 0.8 life-years gained (LYG) (95% confidence interval: 0.4, 1.3) and a decrease in lifetime costs of EUR 7288 (USD 8016) (95% confidence interval: EUR 5730 [USD 6303], EUR 10,620 [USD 11,682]) per patient, compared with the SOC group, resulting in a dominant mean incremental cost-effectiveness ratio (ICER). A compliance with the Barcelona Clinic Liver Classification (BCLC) guidelines for earlier stage contributed to the greater part of the ICER. CONCLUSION: The extended use of ablation in cirrhotic patients with HCC was more effective and less expensive than the non-extended use of the ablation strategy.

Cost-Utility Analysis of Transarterial Radioembolization With Yttrium-90 Resin Microspheres Compared With Sorafenib in Locally Advanced and Inoperable Hepatocellular Carcinoma.

PURPOSE: The SARAH (Sorafenib Versus Radioembolization in Advanced Hepatocellular Carcinoma) trial (ClinicalTrials.gov Identifier NCT01482442) did not show a significant survival benefit for patients treated with transarterial radioembolization (TARE) compared with continuous oral sorafenib. The improved toxicity profile of patients treated with TARE in the trial, however, could result in a quality of life benefit in economic evaluations. Our objective was to perform a cost-utility analysis of TARE versus sorafenib for locally advanced and inoperable hepatocellular carcinoma. METHODS: This study used patient-level data of the SARAH trial regarding resource use, progression-free and overall survival, and quality of life for the within-trial period for the patients who received at least 1 dose of sorafenib or 1 treatment with TARE according to their randomization arm. Data were extrapolated by using a partitioned survival model that incorporated costs and health outcomes, measured in life-years and quality-adjusted life-years (QALYs). FINDINGS: The use of TARE resulted in an average loss of 0.036 life-year and a gain of 0.006 QALY compared with sorafenib. The aerage cost for the TARE arm was €17,179 (95% CI, 9,926-24,280) higher than the sorafenib arm, for an incremental cost-effectiveness ratio of €3,153,086/QALY. The probabilistic sensitivity analysis revealed a 50% risk that the TARE strategy was dominated. TARE was consistently dominated by sorafenib or had an incremental cost-effectiveness ratio more than €450,000/QALY in all sensitivity analyses. IMPLICATIONS: This economic evaluation of SARAH found that using radioembolization with yttrium-90 microspheres for the treatment of hepatocellular carcinoma was not a cost-effective option at the usually accepted willingness-to-pay thresholds.

Impact of COVID-19 on the management of hepatocellular carcinoma in a high-prevalence area.

BACKGROUND & AIMS: Patients affected by hepatocellular carcinoma (HCC) represent a vulnerable population during the COVID-19 pandemic and may suffer from altered allocation of healthcare resources. The aim of this study was to determine the impact of the COVID-19 pandemic on the management of patients with HCC within 6 referral centres in the metropolitan area of Paris, France. METHODS: We performed a multicentre, retrospective, cross-sectional study on the management of patients with HCC during the first 6 weeks of the COVID-19 pandemic (exposed group), compared with the same period in 2019 (unexposed group). We included all patients discussed in multidisciplinary tumour board (MTB) meetings and/or patients undergoing a radiological or surgical programmed procedure during the study period, with curative or palliative intent. Endpoints were the number of patients with a modification in the treatment strategy, or a delay in decision-to-treat. RESULTS: After screening, n = 670 patients were included (n = 293 exposed to COVID, n = 377 unexposed to COVID). Fewer patients with HCC presented to the MTB in 2020 (p = 0.034) and fewer had a first diagnosis of HCC (n = 104 exposed to COVID, n = 143 unexposed to COVID, p = 0.083). Treatment strategy was modified in 13.1% of patients, with no differences between the 2 periods. Nevertheless, 21.5% vs. 9.5% of patients experienced a treatment delay longer than 1 month in 2020 compared with 2019 (p <0.001). In 2020, 7.1% (21/293) of patients had a diagnosis of an active COVID-19 infection: 11 (52.4%) patients were hospitalised and 4 (19.1%) patients died. CONCLUSIONS: In a metropolitan area highly impacted by the COVID-19 pandemic, we observed fewer patients with HCC, and similar rates of treatment modification, but with a significantly longer treatment delay in 2020 vs. 2019. LAY SUMMARY: During the coronavirus disease 2019 (COVID-19) pandemic era, fewer patients with hepatocellular carcinoma (HCC) presented to the multidisciplinary tumour board, especially with a first diagnosis of HCC. Patients with HCC had a treatment delay that was longer in the COVID-19 period than in 2019.

Hepatocellular carcinoma surveillance with ultrasound-cost-effectiveness, high-risk populations, uptake.

Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer and the second cause of cancer-related deaths worldwide. In most cases, it is diagnosed in patients with identified risk factors, mainly cirrhosis from all causes. These patients are candidates for a surveillance program that, depending on guidelines, involves regular liver ultrasound alone or combined with serum markers. These programs have been shown to improve the oncological outcome by detecting earlier stage tumors and providing patients with potentially curative treatment and improved survival. Yet, the level of evidence supporting these guidelines remains limited. This review article presents an overview of the evidence supporting surveillance programs for hepatocellular carcinoma, in particular the efficacy, cost-effectiveness, and consequences of this approach for patient survival. Western and Eastern guideline recommendations are described and discussed.

Assessment of biopsy-proven liver fibrosis by two-dimensional shear wave elastography: An individual patient data-based meta-analysis.

Two-dimensional shear wave elastography (2D-SWE) has proven to be efficient for the evaluation of liver fibrosis in small to moderate-sized clinical trials. We aimed at running a larger-scale meta-analysis of individual data. Centers which have worked with Aixplorer ultrasound equipment were contacted to share their data. Retrospective statistical analysis used direct and paired receiver operating characteristic and area under the receiver operating characteristic curve (AUROC) analyses, accounting for random effects. Data on both 2D-SWE and liver biopsy were available for 1,134 patients from 13 sites, as well as on successful transient elastography in 665 patients. Most patients had chronic hepatitis C (n = 379), hepatitis B (n = 400), or nonalcoholic fatty liver disease (n = 156). AUROCs of 2D-SWE in patients with hepatitis C, hepatitis B, and nonalcoholic fatty liver disease were 86.3%, 90.6%, and 85.5% for diagnosing significant fibrosis and 92.9%, 95.5%, and 91.7% for diagnosing cirrhosis, respectively. The AUROC of 2D-SWE was 0.022-0.084 (95% confidence interval) larger than the AUROC of transient elastography for diagnosing significant fibrosis (P = 0.001) and 0.003-0.034 for diagnosing cirrhosis (P = 0.022) in all patients. This difference was strongest in hepatitis B patients. CONCLUSION: 2D-SWE has good to excellent performance for the noninvasive staging of liver fibrosis in patients with hepatitis B; further prospective studies are needed for head-to-head comparison between 2D-SWE and other imaging modalities to establish disease-specific appropriate cutoff points for assessment of fibrosis stage. (Hepatology 2018;67:260-272).

Robust sound speed estimation for ultrasound-based hepatic steatosis assessment.

Hepatic steatosis is a common condition, the prevalence of which is increasing along with non-alcoholic fatty liver disease (NAFLD). Currently, the most accurate noninvasive imaging method for diagnosing and quantifying hepatic steatosis is MRI, which estimates the proton-density fat fraction (PDFF) as a measure of fractional fat content. However, MRI suffers several limitations including cost, contra-indications and poor availability. Although conventional ultrasound is widely used by radiologists for hepatic steatosis assessment, it remains qualitative and operator dependent. Interestingly, the speed of sound within soft tissues is known to vary slightly from muscle (1.575 mm · µs-1) to fat (1.450 mm · µs-1). Building upon this fact, steatosis could affect liver sound speed when the fat content increases. The main objectives of this study are to propose a robust method for sound speed estimation (SSE) locally in the liver and to assess its accuracy for steatosis detection and staging. This technique was first validated on two phantoms and SSE was assessed with a precision of 0.006 and 0.003 mm · µs-1 respectively for the two phantoms. Then a preliminary clinical trial (N = 17 patients) was performed. SSE results was found to be highly correlated with MRI proton density fat fraction (R 2 = 0.69) and biopsy (AUROC = 0.952) results. This new method based on the assessment of spatio-temporal properties of the local speckle noise for SSE provides an efficient way to diagnose and stage hepatic steatosis.

Assessment of the residual tumour of colorectal liver metastases after chemotherapy: diffusion-weighted MR magnetic resonance imaging in the peripheral and entire tumour.

OBJECTIVES: To evaluate the value of diffusion-weighted imaging (DWI) in detecting residual tumours (RTs) in colorectal liver metastases (CLMs) following chemotherapy, with a focus on tumour periphery. METHODS: From January 2009-January 2012, 57 patients who underwent liver resection for CLMs with preoperative MRI (<3 months) including DWI were retrospectively included. CLMs were classified into three response groups on pathology: (1) major histological (MHR, RTs ≤ 10 %), (2) partial histological (PHR, RT = 10-49 %), and (3) no histological (NHR, RT ≥ 50 %). On DWI, regions of interest (ROIs) were drawn around the entire tumour and tumour periphery. Apparent diffusion (ADC) and pure diffusion (D) coefficients were calculated using a monoexponential fit, and compared using Kruskal-Wallis test on a lesion-per-lesion analysis. RESULTS: 111 CLMs were included. Fourteen (12.5 %), 42 (38 %) and 55 (49.5 %) CLMs presented a MHR, PHR and NHR, respectively. ADC and D of the peripheral ROIs were significantly higher in the MHR group (P = 0.013/P = 0.013). ADC and D from the entire tumour were not significantly different among the groups (P = 0.220/P = 0.103). CONCLUSION: In CLM treated with chemotherapy, ADC and D values from the entire tumour are not related to the degree of RT, while peripheral zone diffusion parameters could help identify metastases with MHR. KEY POINTS: Peripheral ADC and D of CLMs were higher with major pathological responses. Global ADC and D of CLMs were not different according to residual tumour. Diffusion-weighted images of CLM periphery could be an interesting biomarker of MHR. Diffusion-weighted images could be used to help tailor treatment.

Assessment of liver ablation using cone beam computed tomography.

AIM: To investigate the feasibility and accuracy of cone beam computed tomography (CBCT) in assessing the ablation zone after liver tumor ablation. METHODS: Twenty-three patients (17 men and 6 women, range: 45-85 years old, mean age 65 years) with malignant liver tumors underwent ultrasound-guided percutaneous tumor ablation [radiofrequency (n = 14), microwave (n = 9)] followed by intravenous contrast-enhanced CBCT. Baseline multidetector computed tomography (MDCT) and peri-procedural CBCT images were compared. CBCT image quality was assessed as poor, good, or excellent. Image fusion was performed to assess tumor coverage, and quality of fusion was rated as bad, good, or excellent. Ablation zone volumes on peri-procedural CBCT and post-procedural MDCT were compared using the non-parametric paired Wilcoxon t-test. RESULTS: Rate of primary ablation effectiveness was 100%. There were no complications related to ablation. Local tumor recurrence and new liver tumors were found 3 mo after initial treatment in one patient (4%). The ablation zone was identified in 21/23 (91.3%) patients on CBCT. The fusion of baseline MDCT and peri-procedural CBCT images was feasible in all patients and showed satisfactory tumor coverage (at least 5-mm margin). CBCT image quality was poor, good, and excellent in 2 (9%), 8 (35%), and 13 (56%), patients respectively. Registration quality between peri-procedural CBCT and post-procedural MDCT images was good to excellent in 17/23 (74%) patients. The median ablation volume on peri-procedural CBCT and post-procedural MDCT was 30 cm(3) (range: 4-95 cm(3)) and 30 cm(3) (range: 4-124 cm(3)), respectively (P-value > 0.2). There was a good correlation (r = 0.79) between the volumes of the two techniques. CONCLUSION: Contrast-enhanced CBCT after tumor ablation of the liver allows early assessment of the ablation zone.

Radioembolisation with yttrium‒90 microspheres versus sorafenib for treatment of advanced hepatocellular carcinoma (SARAH): study protocol for a randomised controlled trial.

BACKGROUND: Untreated advanced hepatocellular carcinoma (HCC) is linked to poor prognosis. While sorafenib is the current recommended treatment for advanced HCC, radioembolisation (RE; also called selective internal radiation therapy or SIRT) with yttrium-90 microspheres has shown efficacy in cohort studies. However, there are no head-to-head trials comparing radiation therapy with yttrium-90 microspheres and sorafenib in advanced HCC. The SARAH trial has been designed to compare the efficacy and safety of sorafenib therapy and RE using yttrium-90 resin microspheres (SIR-Spheres™; Sirtex Medical Limited, North Sydney, Australia) in patients with advanced HCC. Quality of life (QoL) and cost-effectiveness will also be compared between therapies. METHODS/DESIGN: SARAH is a prospective, randomised, controlled, open-label, multicentre trial comparing the efficacy of RE with sorafenib in the treatment of patients with advanced HCC. The trial aims to recruit adults with a life expectancy of >3 months, Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1, and: advanced HCC according to the Barcelona criteria (stage C) or recurrent HCC after surgical or thermoablative treatment who are not eligible for surgical resection, liver transplantation or thermal ablation; or two rounds of failed chemoembolisation. Patients will be randomised 1:1 to receive either RE or sorafenib 400 mg twice daily. All patients will be monitored for between 12 and 48 months following start of treatment. The primary endpoint of the SARAH trial is overall survival (OS). Secondary endpoints include: adverse events, progression-free survival at 6 months; tumour response rate; general or liver disease-specific QoL scores; and cost of each treatment strategy. Assuming an increase in median OS of 4 months with RE versus sorafenib therapy, randomising at least 400 patients (200 in each treatment arm) will be sufficient for 80% power and a bilateral alpha risk of 5%; therefore, 440 patients will be enrolled to allow for 10% loss of patients due to ineligibility. DISCUSSION: The SARAH trial is the first randomised head-to-head study to compare RE with sorafenib in advanced HCC, and will establish the potential role of RE in HCC treatment guidelines. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01482442, first received 28 November 2011.

Validation of dynamic contrast-enhanced ultrasound in predicting outcomes of antiangiogenic therapy for solid tumors: the French multicenter support for innovative and expensive techniques study.

OBJECTIVES: Dynamic contrast-enhanced ultrasound (DCE-US) has been used in single-center studies to evaluate tumor response to antiangiogenic treatments: the change of area under the perfusion curve (AUC), a criterion linked to blood volume, was consistently correlated with the Response Evaluation Criteria in Solid Tumors response. The main objective here was to do a multicentric validation of the use of DCE-US to evaluate tumor response in different solid tumor types treated by several antiangiogenic agents. A secondary objective was to evaluate the costs of the procedure. MATERIALS AND METHODS: This prospective study included patients from 2007 to 2010 in 19 centers (8 teaching hospitals and 11 comprehensive cancer centers). All patients treated with antiangiogenic therapy were eligible. Dynamic contrast-enhanced ultrasound examinations were performed at baseline as well as on days 7, 15, 30, and 60. For each examination, a perfusion curve was recorded during 3 minutes after injection of a contrast agent. Change from baseline at each time point was estimated for each of 7 fitted criteria. The main end point was freedom from progression (FFP). Criterion/time-point combinations with the strongest correlation with FFP were analyzed further to estimate an optimal cutoff point. RESULTS: A total of 1968 DCE-US examinations in 539 patients were analyzed. The median follow-up was 1.65 years. Variations from baseline were significant at day 30 for several criteria, with AUC having the most significant association with FFP (P = 0.00002). Patients with a greater than 40% decrease in AUC at day 30 had better FFP (P = 0.005) and overall survival (P = 0.05). The mean cost of each DCE-US was 180&OV0556;, which corresponds to $250 using the current exchange rate. CONCLUSIONS: Dynamic contrast-enhanced ultrasound is a new functional imaging technique that provides a validated criterion, namely, the change of AUC from baseline to day 30, which is predictive of tumor progression in a large multicenter cohort. Because of its low cost, it should be considered in the routine evaluation of solid tumors treated with antiangiogenic therapy.

Assessment of portal hypertension and high-risk oesophageal varices with liver and spleen three-dimensional multifrequency MR elastography in liver cirrhosis.

OBJECTIVE: To assess the value of the liver and spleen viscoelastic parameters at multifrequency MR elastography to determine the degree of portal hypertension and presence of high-risk oesophageal varices in patients with cirrhosis. METHODS: From January to September 2012, 36 consecutive patients with cirrhosis evaluated for transplantation were prospectively included. All patients underwent hepatic venous pressure gradient (HVPG) measurements and endoscopy to assess oesophageal varices. Multifrequency MR elastography was performed within the liver and spleen. The shear, storage and loss moduli were calculated and compared to the HVPG with Spearman coefficients and multiple regressions. Patients with and without severe portal hypertension and high-risk varices were compared with Mann-Whitney tests, logistic regression and ROC analysis. RESULTS: The liver storage and loss moduli and the spleen shear, storage and loss moduli correlated with the HVPG. At multiple regression, only the liver and the spleen loss modulus correlated with the HVPG (r = 0.44, p = 0.017, and r = 0.57, p = 0.002, respectively). The spleen loss modulus was the best parameter for identifying patients with severe portal hypertension (p = 0.019, AUROC = 0.81) or high-risk varices (p = 0.042, AUROC = 0.93). CONCLUSIONS: The spleen loss modulus appears to be the best parameter for identifying patients with severe portal hypertension or high-risk varices. KEY POINTS: 1. Noninvasive HVPG assessment can be performed with liver and spleen MR elastography 2. The spleen loss modulus enables the detection of high-risk oesophageal varices 3. The spleen loss modulus enables the detection of severe portal hypertension.

Colon tumor growth and antivascular treatment in mice: complementary assessment with MR elastography and diffusion-weighted MR imaging.

PURPOSE: To investigate the potential value of magnetic resonance (MR) elastography and diffusion-weighted (DW) MR imaging in the detection of microstructural changes of murine colon tumors during growth and antivascular treatment. MATERIALS AND METHODS: The study was approved by the regional ethics committee for animal care. Sixty Balb-C mice, bearing ectopic and orthotopic colon tumors, were monitored for 3 weeks with high-resolution T2-weighted MR imaging, three-dimensional steady-state MR elastography, and DW MR imaging at 7 T. The same imaging protocol was performed 24 hours after injection of combretastatin A4 phosphate (CA4P) in 12 mice. The absolute value of the complex shear modulus (|G*|) and the apparent diffusion coefficient (ADC) were measured in the viable zones of tumors and compared with microvessel density (MVD), cellularity, and micronecrosis by using the Pearson correlation coefficient. RESULTS: During tumor growth, |G*| increase was correlated with MVD (r = 0.70 [P = .08] and r = 0.78 [P = .002], for both the ectopic and orthotopic models, respectively). Moreover, the ectopic tumors displayed decreased ADC, which correlated with increased cellularity (r = 0.77, P = .04), whereas no changes in ADC and cellularity were observed in orthotopic tumors. After CA4P administration, |G*| decreased in the ectopic model (P < .0001), similar to the MVD evolution (P = .03), whereas no significant changes in |G*| (P = .7) and MVD (P = .6) were observed in the orthotopic model. ADC increased in both models (P = .047 and P = .01 for the ectopic and the orthotopic models, respectively) in relation to increased micronecrosis. CONCLUSION: Imaging of mechanical properties and diffusivity provide complementary information during tumor growth and regression that are respectively linked to vascularity and tumor cell alterations, including cellularity and micronecrosis.

Simultaneous assessment of liver volume and whole liver fat content: a step towards one-stop shop preoperative MRI protocol.

OBJECTIVE: The purpose of this study was to evaluate the ability of a whole liver volume (WLV) segmentation algorithm to measure fat fraction (FF). METHODS: Twenty consecutive patients with histologically proven fatty liver disease underwent dual-echo in-phase/out-of-phase MRI and magnetic resonance spectroscopy (MRS) at 1.5 T. Two readers independently performed semiautomatic 3D liver segmentation on the out-of-phase sequences using an active contour model. FF was calculated for voxels, segments and WLV. Segmentation inter-observer reproducibility was assessed by intra-class correlation coefficient (ICC) for WLV and FF. Fat fraction correlation and agreement as determined by histology, MRS and MRI were determined. RESULTS: ICC was 0.999 (95% CI: 0.999-1, P < 0.001) for WLV FF calculation and 0.996 (95% CI: 0.990-0.998, P < 0.001) for whole liver volume calculations. Strong correlations were found between FF measured by histology, MRS and WLV-MRI. A Bland-Altman analysis showed a good agreement between FF measured by MRS and WLV-MRI. No systematic variations of FF was found between segments when analyzed by ANOVA (F = 1.78, P = 0.096). CONCLUSION: This study shows that a reproducible whole liver volume segmentation method to measure fat fraction can be performed. This strategy may be integrated to a "one-stop shop" protocol in liver surgery planning.

A hand-held ultrasound machine vs. conventional ultrasound machine in the bedside assessment of post-liver transplant patients.

The purpose was to assess the diagnostic accuracy of a hand-held Doppler ultrasound (US) machine for the bedside detection of liver and vascular abnormalities after liver transplantation in the intensive care unit. The IRB approved this study, and written informed consent was obtained from all patients or the patient's legal representative. Any liver transplant recipient at our institution who needed a bedside Doppler US examination in the intensive care unit was eligible. Patients underwent routine grey-scale, colour, and spectral Doppler US examinations of the liver with a conventional machine, which was taken as the reference method, and with a hand-held machine on the same day. Examinations followed one another and were performed in a blinded fashion by two radiologists. Over a 4-month period, 24 consecutive patients (16 men, median age 54 years old; 16 cadaveric and 8 living related right liver transplantations) underwent 43 examinations with both conventional and hand-held machines. Image quality and overall satisfaction scores of grey-scale were lower with the hand-held than with the conventional machine. The hand-held was similar to the conventional machine for assessing the patency of portal veins, hepatic veins and the IVC in all patients but one. The hand-held machine failed to detect signals in the right branch of the hepatic artery and in the hilum in two and one cases, respectively. There was no abnormal hepatic arterial flow with the conventional machine in any of the patients, and the results were the same with the hand-held machine. Total examination time was significantly longer with the hand-held machine. The hand-held US machine had a high diagnostic accuracy for both parenchymal and vascular analyses compared with a conventional US machine in the bedside assessment of post-liver transplant patients.

Ischemic complications after pancreaticoduodenectomy: incidence, prevention, and management.

OBJECTIVE: To assess prevalence, prevention, and management strategy of visceral ischemic complications after pancreaticoduodenectomy (PD). BACKGROUND: Ischemic complications after PD resulting from preexisting celiac axis (CA), superior mesenteric artery (SMA), stenosis, or intraoperative arterial trauma appear as an underestimated cause of death. Their prevention and adequate management are challenging. METHODS: From 1995 to 2006, 545 PD were performed in our institution. All patients were evaluated by thin section multidetector computed tomography (CT) with arterial reconstruction to detect and class SMA or CA stenosis. Hemodynamical significance of stenosis was assessed preoperatively by arteriography for atherosclerotic stenosis and intraoperatively by gastroduodenal artery clamping test for CA compression by median arcuate ligament. Significant atherosclerotic stenosis was stented or bypassed, whereas CA compression was treated by median arcuate ligament division during PD. Multidetector-CT accuracy to detect arterial stenosis, results of revascularization procedures, and both prevalence and prognosis of ischemic complications after PD were analyzed. RESULTS: Among 62 (11%) stenoses detected by multidetector-CT, 27 (5%) were hemodynamically significant, including 23 CA compressions by median arcuate ligament, 2 CA, and 2 SMA atherosclerotic stenoses, respectively. All atherosclerotic stenoses were successfully treated by preoperative stenting (n = 3) or bypass (n = 1). Among the 23 cases who underwent median arcuate ligament division, 3 (13%) failed due to 1 CA injury and 2 misdiagnosed intrinsic CA stenoses. Overall, 6 patients developed ischemic complications, due to intraoperative hepatic artery injury (n = 4), unrecognized SMA atherosclerotic stenosis (n = 1), or CA fibromuscular dysplasia (n = 1). Five (83%) of them died, representing 36% of the 14 deaths of the whole series (overall mortality = 2.6%). Overall, CT detected significant arterial stenosis with a 96% sensitivity and determined etiology of CA stenosis with a 92% accuracy. CONCLUSIONS: Ischemic complications are an underestimated cause of death after PD and are due to preexisting stenoses of CA and SMA, or intraoperative hepatic artery injury. Preexisting arterial stenoses are detected by routine multidetector CT. Preoperative endovascular stenting for intrinsic stenosis, division of median arcuate ligament for extrinsic compression, and meticulous dissection of the hepatic artery can contribute to minimize ischemic complications.