Non-invasive response prediction in prophylactic carvedilol therapy for cirrhotic patients with esophageal varices.

BACKGROUND & AIMS: Non-selective beta-blockers (NSBBs) are the mainstay of primary prophylaxis of esophageal variceal bleeding in patients with liver cirrhosis. We investigated whether non-invasive markers of portal hypertension correlate with hemodynamic responses to NSBBs in cirrhotic patients with esophageal varices. METHODS: In this prospective cohort study, 106 cirrhotic patients with high-risk esophageal varices in the derivation cohort received carvedilol prophylaxis, and completed paired measurements of hepatic venous pressure gradient, liver stiffness (LS), and spleen stiffness (SS) at the beginning and end of dose titration. LS and SS were measured using acoustic radiation force impulse imaging. A prediction model for hemodynamic response was derived, and subject to an external validation in the validation cohort (63 patients). RESULTS: Hemodynamic response occurred in 59 patients (55.7%) in the derivation cohort, and in 33 patients (52.4%) in the validation cohort, respectively. Multivariate logistic regression analysis identified that ΔSS was the only significant predictor of hemodynamic response (odds ratio 0.039; 95% confidence interval 0.008-0.135; p <0.0001). The response prediction model (ModelΔSS = 0.0490-2.8345 × ΔSS; score = (exp[ModelΔSS])/(1 + exp[ModelΔSS]) showed good predictive performance (area under the receiver-operating characteristic curve [AUC] = 0.803) using 0.530 as the threshold value. The predictive performance of the ModelΔSS in the validation set improved using the same threshold value (AUC = 0.848). CONCLUSION: A new model based on dynamic changes in SS exhibited good performance in predicting hemodynamic response to NSBB prophylaxis in patients with high-risk esophageal varices. LAY SUMMARY: Non-selective beta-blockers are the mainstay of primary prophylaxis to prevent variceal bleeding in patients with cirrhosis and high-risk esophageal varices. This prospective study showed that a prediction model based on changes in spleen stiffness before vs. after dose titration might be a non-invasive marker for response to prophylactic non-selective beta-blocker (carvedilol) therapy in patients with cirrhosis and high-risk esophageal varices. ClinicalTrials.gov Identifier: NCT01943318.

Prediction of Local Tumor Progression after Radiofrequency Ablation (RFA) of Hepatocellular Carcinoma by Assessment of Ablative Margin Using Pre-RFA MRI and Post-RFA CT Registration.

Objective: To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison. Materials and Methods: In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (≥ 3 mm) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method. Results: The two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79). Conclusion: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

Correction to: Magnetic resonance with diffusion-weighted imaging improves assessment of focal liver lesions in patients with potentially resectable pancreatic cancer on CT.

The original version of this article, published on 19 January 2018, unfortunately contained a mistake.

Is Prostate Imaging Reporting and Data System Version 2 Sufficiently Discovering Clinically Significant Prostate Cancer? Per-Lesion Radiology-Pathology Correlation Study.

OBJECTIVE: The objective of our study was to evaluate the performance of multiparametric MRI with Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) for detecting prostate cancer (PCA) and clinically significant PCA through this per-lesion one-to-one correlation study between pathologically proven lesions and MRI-visible lesions. MATERIALS AND METHODS: A total of 93 PCA lesions from 44 patients who underwent radical prostatectomy were included in this retrospective study. Two radiologists scored every visible lesion with a PI-RADSv2 score of 3, 4, or 5 in each patient's multiparametric MRI examination using PI-RADSv2. A per-lesion one-to-one correlation between MRI-visible lesions and pathologically confirmed PCA lesions was conducted during regular radiology-pathology meetings at our center. The detection rates of clinically significant PCA and the proportions of clinically significant PCAs from MRI-visible and MRI-invisible PCAs were calculated. The performance of PI-RADSv2 for detecting clinically significant PCA was evaluated using the positive predictive value (PPV), negative predictive value (NPV), and area under the ROC curve (AUC) value. RESULTS: Using a PI-RADSv2 score of 3, 4, or 5 as an MRI-visible lesion, 46.88% of clinically significant PCA lesions were detected. The PPV, NPV, and AUC were 96.77%, 45.16%, and 0.72, respectively. Tumor volume and secondary Gleason grade showed a statistically significant difference between MRI-visible and MRI-invisible clinically significant PCAs. CONCLUSION: Multiparametric MRI with PI-RADSv2 missed a considerable number of clinically significant PCA lesions in this per-lesion analysis, causing a relatively low NPV and diagnostic performance compared with previous per-patient studies. However, the high PPV indicates that multiparametric MRI with PI-RADSv2 may be useful for follow-up of active surveillance and planning focal therapy.

Magnetic resonance with diffusion-weighted imaging improves assessment of focal liver lesions in patients with potentially resectable pancreatic cancer on CT.

PURPOSE: To investigate added value of MRI to preoperative staging MDCT for evaluation of focal liver lesions (FLLs) in potentially resectable pancreatic ductal adenocarcinomas (PDACs). MATERIALS AND METHODS: In patients with potentially resectable PDACs after staging MDCT (n=167), characteristics of FLLs were scored as benign, indeterminate or metastases on an MDCT set and combined MDCT and MRI set by two readers, independently. Size of hepatic lesions was measured and detection rate of hepatic metastasis unsuspected by MDCT and diagnostic yield of MRI for FLLs were assessed. RESULTS: Reader-averaged figure-of-merit (FOM) of the combined set was significantly higher than that of MDCT alone (0.94 vs. 0.86, p=.028). In the negative-on-CT group, the diagnostic yield of MRI was 1.5-2.3% (2/133 and 3/133 for readers 1 and 2, respectively). In the indeterminate-on-CT group, MRI yield was 10.5-13.6% (2/19 and 3/22) and in patients with suspicious-metastasis-on-CT, 8.3-26.7% (1/12 and 4/15). All lesions with false-positive and false-negative CT findings were ≤1 cm. CONCLUSION: In potentially resectable PDACs, addition of MRI with DWI can provide significantly better diagnostic performance in characterization of focal liver lesions, especially for small-sized (≤ 1 cm) MDCT-indeterminate or suspicious metastasis lesions, aiding in determination of appropriate operation candidates. KEY POINTS: • Addition of MRI provides better diagnostic performance in characterization of liver lesions. • Combined interpretation of MRI and MDCT provided less frequent indeterminate liver lesions. • Diagnostic yield of MRI was high in CT-indeterminate or suspicious metastatic lesions. • Operation candidates can be determined with greater confidence in potentially resectable PDACs.

Prospective comparison among transient elastography, supersonic shear imaging, and ARFI imaging for predicting fibrosis in nonalcoholic fatty liver disease.

The diagnostic performance of supersonic shear imaging (SSI) in comparison with those of transient elastography (TE) and acoustic radiation force impulse imaging (ARFI) for staging fibrosis in nonalcoholic fatty liver disease (NAFLD) patients has not been fully assessed, especially in Asian populations with relatively lean NAFLD compared to white populations. Thus, we focused on comparing the diagnostic performances of TE, ARFI, and SSI for staging fibrosis in a head-to-head manner, and identifying the clinical, anthropometric, biochemical, and histological features which might affect liver stiffness measurement (LSM) in our prospective biopsy-proven NAFLD cohort. In this study, ninety-four patients with biopsy-proven NAFLD were included prospectively. Liver stiffness was measured using TE, SSI, and ARFI within 1 month of liver biopsy. The diagnostic performance for staging fibrosis was assessed using receiver operating characteristic (ROC) analysis. Anthropometric data were evaluated as covariates influencing LSM by regression analyses. Liver stiffness correlated with fibrosis stage (p < 0.05); the area under the ROC curve of TE (kPa), SSI (kPa), and ARFI (m/s) were as follows: 0.757, 0.759, and 0.657 for significant fibrosis and 0.870, 0.809, and 0.873 for advanced fibrosis. Anthropometric traits were significant confounders affecting SSI, while serum liver injury markers significantly confounded TE and ARFI. In conclusion, the LSM methods had similar diagnostic performance for staging fibrosis in patients with NAFLD. Pre-LSM anthropometric evaluation may help predict the reliability of SSI.

Ruptured Corpus Luteal Cyst: Prediction of Clinical Outcomes with CT.

OBJECTIVE: To evaluate the determinant pretreatment CT findings that can predict surgical intervention for patients suffering from corpus luteal cyst rupture with hemoperitoneum. MATERIALS AND METHODS: From January 2009 to December 2014, a total of 106 female patients (mean age, 26.1 years; range, 17-44 years) who visited the emergency room of our institute for acute abdominal pain and were subsequently diagnosed with ruptured corpus luteal cyst with hemoperitoneum were included in the retrospective study. The analysis of CT findings included cyst size, cyst shape, sentinel clot sign, ring of fire sign, hemoperitoneum depth, active bleeding in portal phase and attenuation of hemoperitoneum. The comparison of CT findings between the surgery and conservative management groups was performed with the Mann-Whitney U test or chi-square test. Logistic regression analysis was used to determine significant CT findings in predicting surgical intervention for a ruptured cyst. RESULTS: Comparative analysis revealed that the presence of active bleeding and the hemoperitoneum depth were significantly different between the surgery and conservative management groups and were confirmed as significant CT findings for predicting surgery, with adjusted odds ratio (ORs) of 3.773 and 1.318, respectively (p < 0.01). On the receiver-operating characteristic curve analysis for hemoperitoneum depth, the optimal cut-off value was 5.8 cm with 73.7% sensitivity and 58.6% specificity (Az = 0.711, p = 0.004). In cases with a hemoperitoneum depth > 5.8 cm and concurrent active bleeding, the OR for surgery increased to 5.786. CONCLUSION: The presence of active bleeding and the hemoperitoneum depth on a pretreatment CT scan can be predictive warning signs of surgery for a patient with a ruptured corpus luteal cyst with hemoperitoneum.

Standard vs. reduced-radiation-dose CT in the tracing of the ureter.

PURPOSE: To assess the effectiveness of reduced-radiation-dose computed tomography (CT) protocols in the tracing of the ureter in patients with suspected renal colic. METHODS: The study was approved by our institutional review board, and informed consent was obtained from the participants. From July 2012 to April 2014, 310 consecutive patients with suspected urolithiasis were recruited to undergo unenhanced CT at 280 (n = 62), 200 (n = 62), 140 (n = 62), 100 (n = 62), and 70 (n = 62) reference mA seconds (mAs) while keeping other imaging parameters constant. Images were independently and randomly reviewed by two radiologists blinded to the study to determine the tracing rates of the ureter and the acceptable rates of image quality according to different tube charge settings. RESULTS: A significant linear association was noted between tube charge settings, the rates for tracing of the ureter, and the acceptability of image quality (linear-by-linear association; p = 0.000 in all rates for both readers). The 140 reference mAs is the point at which the tracing rates deteriorate rapidly, with the tracing rate of 41.5% (95% CI 32.6%-51.0%) in reader 1 and 51.9% (95% CI 42.5%-61.2%) in reader 2, and with the acceptable rate of 82.3% (95% CI 70.8%-90.0%) in reader 1 and 96.8% (95% CI 88.3%-99.8%) in reader 2. CONCLUSION: Decreasing the tube charge settings from 280 to 70 reference mAs resulted in a significant reduction in the tracing rate of the ureter, with 140 reference mAs being the breaking point.

In-vivo monitoring of development of cholangiocarcinoma induced with C. sinensis and N-nitrosodimethylamine in Syrian golen hamsters using ultrasonography and magnetic resonance imaging: a preliminary study.

OBJECTIVES: The purpose of this study is to evaluate high-resolution ultrasound and magnetic resonance imaging (MRI) in monitoring of cholangiocarcinoma in the hamsters with C. sinensis infection and N-nitrosodimethylamine (NDMA). MATERIALS AND METHODS: Twenty-four male Syrian golden hamsters of were divided into four groups composed of five hamsters as control, five hamsters receiving 30 metacercariae of C. sinensis per each hamster, five hamsters receiving NDMA in drinking water, and nine hamsters receiving both metacercariae and NDMA. Ultrasound was performed every other week from baseline to the 12th week of infection. MRI and histopathologic examination was done from the 4th week to 12th week. RESULTS: Cholangiocarcinomas appeared as early as the 6th week of infection. There were 12 cholangiocarcinomas, nine and ten of which were demonstrated by ultrasound and MRI, respectively. Ultrasound and MRI findings of cholangiocarcinomas in the hamsters were similar to those of the mass-forming intrahepatic cholangiocarcinomas in humans. Ultrasound and MRI also showed other findings of disease progression such as periductal increased echogenicity or signal intensity, ductal dilatation, complicated cysts, and sludges in the gallbladder. CONCLUSIONS: High-resolution ultrasound and MRI can monitor and detect the occurrence of cholangiocarcinoma in the hamsters non-invasively. KEY POINTS: • High-resolution ultrasound and MRI can monitor occurrence of cholangiocarcinoma in the hamsters. • Cholangiocarcinomas were detected as early as the 6th week after C. sinensis infection. • Axial T2-weighted MRI demonstrated cholangiocarcinomas and various inflammatory findings in the hamsters.

Improved Cycling Performance of Lithium-Oxygen Cells by Use of a Lithium Electrode Protected with Conductive Polymer and Aluminum Fluoride.

Lithium-oxygen batteries have attracted great attention for advanced energy storage systems because of their high specific energy. The enhancement of the interfacial stability of lithium negative electrodes is one of the many technical challenges toward high safety and long life lithium-oxygen batteries due to their high reactivity toward organic electrolytes and the lithium dendrite growth during the repeated cycling. Herein, we demonstrate that the protective layer comprising conductive polymer and AlF3 particles on lithium metal stabilized the lithium electrode by effectively reducing the reductive decomposition of the liquid electrolyte and suppressing the growth of lithium dendrite. As a result, the cycling performance of a lithium-oxygen cell assembled with a surface-modified lithium electrode was remarkably improved as compared to a cell with a pristine lithium electrode.

Comparison of the Reliability of Acoustic Radiation Force Impulse Imaging and Supersonic Shear Imaging in Measurement of Liver Stiffness.

PURPOSE: To compare the reliability of acoustic radiation force impulse (ARFI) imaging and supersonic shear imaging (SSI) in measurement of liver stiffness. MATERIALS AND METHODS: This study was approved by the institutional review board, and written informed consent was obtained for all patients. Seventy-nine patients (25 healthy patients, 26 with Child-Pugh class A, and 28 with Child-Pugh class B or C) were enrolled and analyzed from April 2012 to April 2013. In each patient, three abdominal radiologists performed nine measurements of hepatic shear-wave speed with both ARFI imaging and SSI on the same day. Four weeks later, a second session was performed with the same protocol. Interobserver and intraobserver agreements were calculated by using intraclass correlation coefficients. Technical failures and measurement time were evaluated. RESULTS: There were four technical failures in the SSI group and one in the ARFI group (P = .375). The overall interobserver agreement of ARFI imaging was significantly higher than that of SSI (0.941 vs 0.828, P < .001). The overall intraobserver agreement of ARFI imaging was significantly higher than that of SSI (0.915 vs 0.829, P < .001). The overall shear-wave speed measured with SSI was higher than that measured with ARFI imaging (2.04 m/sec ± 0.88 vs 1.80 m/sec ± 0.81, P < .001). The measurement time of SSI was longer than that of ARFI imaging (310.8 seconds ± 88.5 vs 84.5 seconds ± 15.4, P < .001). CONCLUSION: ARFI imaging was more reliable than SSI in measurement of liver stiffness. The hepatic shear-wave speed measured with SSI was higher than that measured with ARFI imaging, which means that the shear-wave speeds measured with ARFI imaging and SSI cannot be used interchangeably.

The Role of Spleen Stiffness in Determining the Severity and Bleeding Risk of Esophageal Varices in Cirrhotic Patients.

Esophageal varix and its hemorrhage are serious complications of liver cirrhosis. Recent studies have focused on noninvasive prediction of esophageal varices. We attempted to evaluate the association of liver and spleen stiffness (LS and SS) as measured by acoustic radiation force impulse imaging, with the presence and severity of esophageal varices and variceal hemorrhage in cirrhotic patients. We measured LS and SS, along with endoscopic examination of esophageal varices for a total of 125 cirrhotic patients at a single referral hospital in this prospective observational study. The diagnostic utility of noninvasive methods for identifying varices and their bleeding risk was compared, including LS, SS, spleen length, Child-Pugh score, and various serum fibrosis indices. Esophageal varices were present in 77 patients (61.6%). SS was significantly higher in patients with varices than in those without varices (3.58 ± 0.47 vs 3.02 ± 0.49; P < 0.001). A tendency toward increasing SS levels was observed with increasing severity of varices (no varix, 3.02 ± 0.49; F1, 3.39 ± 0.51; F2, 3.60 ± 0.42; F3, 3.85 ± 0.37; P < 0.001). SS was significantly higher in patients who experienced variceal hemorrhage than in those who did not (3.80 ± 0.36 vs 3.20 ± 0.51; P = 0.002). An optimal cut-off value of SS for high-risk varices (≥ F2) or variceal hemorrhage was 3.40 m/s. SS was significantly correlated with the presence, severity, and bleeding risk of esophageal varices. Prompt endoscopic evaluation of variceal status and prophylactic measures based on the SS may be warranted for cirrhotic patients.

Differentiating between adenomyomatosis and gallbladder cancer: revisiting a comparative study of high-resolution ultrasound, multidetector CT, and MR imaging.

OBJECTIVE: To compare the diagnostic performance of high-resolution ultrasound (HRUS) with contrast-enhanced CT and contrast-enhanced magnetic resonance imaging (MRI) with MR cholangiopancreatography (MRCP) to differentiate between adenomyomatosis (ADM) and gallbladder cancer (GBCA). MATERIALS AND METHODS: Forty patients with surgically proven ADM (n = 13) or GBCA at stage T2 or lower (n = 27) who previously underwent preoperative HRUS, contrast-enhanced CT, and contrast-enhanced MRI with MRCP were retrospectively included in this study. According to the well-known diagnostic criteria, two reviewers independently analyzed the images from each modality separately with a five-point confidence scale. The interobserver agreement was calculated using weighted κ statistics. A receiver operating characteristic curve analysis was performed and the sensitivity, specificity, and accuracy were calculated for each modality when scores of 1 or 2 indicated ADM. RESULTS: The interobserver agreement between the two reviewers was good to excellent. The mean Az values for HRUS, multidetector CT (MDCT), and MRI were 0.959, 0.898, and 0.935, respectively, without any statistically significant differences between any of the modalities (p > 0.05). The mean sensitivity of MRI with MRCP (80.8%) was significantly higher than that of MDCT (50.0%) (p = 0.0215). However, the mean sensitivity of MRI with MRCP (80.8%) was not significantly different from that of HRUS (73.1%) (p > 0.05). The mean specificities and accuracies among the three modalities were not significantly different (p > 0.05). CONCLUSION: High-resolution ultrasound and MRI with MRCP have comparable sensitivity and accuracy and MDCT has the lowest sensitivity and accuracy for the differentiation of ADM and GBCA.