Assessment of hepatic fibrosis with superb microvascular imaging in hepatitis C virus-associated chronic liver diseases.

AIM: Superb microvascular imaging (SMI) is an ultrasound Doppler technique using a unique algorithm that allows visualization of minute vessels with slow velocity and minimal motion artifacts. The aim of this preliminary study was to investigate whether SMI could predict liver fibrosis by visualizing the vessels present in the vicinity of the liver surface because the morphology of the peripheral hepatic vasculature is affected by the progression of liver fibrosis. METHODS: We recruited 29 patients with biopsy-proven chronic hepatitis C or liver cirrhosis C, and 36 patients without liver disease as controls. Using an Aplio 500 ultrasound system with a 7-MHz or 12-MHz linear probe, we assessed the vascular shapes and the bifurcation angles of five randomly selected vessels in the vicinity of the liver surface. The vascular shape was scored based on the number of winding and/or irregular vessels. RESULTS: The mean vascular score and the mean bifurcation angle were significantly greater in patients with advanced liver fibrosis (3.5 ± 1.1 and 90.5 ± 14.3) than in those with mild-to-moderate liver fibrosis (1.3 ± 1.4 and 68.0 ± 16.1) and controls (0.6 ± 0.7 and 62.2 ± 10.5). The area under the receiver-operating curve of the vascular score and the bifurcation angle were 0.88 with 76.5% sensitivity and 83.3% specificity, and 0.87 with 94.1% sensitivity and 75.0% specificity, respectively. CONCLUSION: The present results indicate that SMI potentially predicts the extent of liver fibrosis by detecting small vessels present in the vicinity of the liver surface.

Contrast-enhanced ultrasonography with Sonazoid for diagnosis of gangrenous cholecystitis.

PURPOSE: This prospective study investigated the ability of contrast-enhanced ultrasonography (CEUS) with Sonazoid to diagnose gangrenous cholecystitis and determined the inter-observer agreement. METHODS: From September 2012 to August 2014, 27 patients with acute cholecystitis underwent preoperative CEUS (registration number 1277). After Sonazoid injection, harmonic imaging of the gallbladder wall was performed, and the findings were recorded using movie clips. The signal intensity was classified as absence (uncomplicated) or presence of perfusion defects (gangrenous). The physician performing CEUS recorded the findings immediately after the examination. Another physician (blinded to the clinical information) then reviewed the movie clips and recorded the findings. The final diagnosis was determined by histological examination in all 27 patients. RESULTS: The final diagnosis was gangrenous cholecystitis in 15 patients and uncomplicated cholecystitis in 12. On CEUS examination, perfusion defects were detected in 10 patients with gangrenous cholecystitis, giving a sensitivity of 66.7 %, specificity of 100 %, positive predictive value of 100 %, and negative predictive value of 70.6 %. On review of the movie clips, these values were 73.3, 100, 100, and 75.0 %, respectively. The inter-observer agreement between physicians was good (κ coefficient, 0.64). CONCLUSIONS: CEUS with Sonazoid is a useful and reproducible modality for diagnosing gangrenous cholecystitis.

Increased enhancement of the liver adjacent to the gallbladder seen with contrast ultrasound: comparison between acute cholecystitis and non-cholecystitis.

BACKGROUND: This study was performed to evaluate the ability of contrast-enhanced ultrasonography (CEUS) with time-intensity curve analysis to demonstrate an increased enhancement of the liver parenchyma adjacent to the inflamed gallbladder, as seen on contrast-enhanced computed tomography. METHODS: The Ethics Committee of our institution approved the study protocol (Kawasaki Medical School, registration number 1277). From April to November 2013, 11 consecutive patients with acute cholecystitis and 16 patients without cholecystitis consented to CEUS (Sonazoid™) and were enrolled in this study. The gallbladder and liver were scanned by one gastroenterologist using harmonic imaging with a low mechanical index. The raw imaging data were stored. Another physician, blinded to all clinical information, constructed the time-intensity curve. The major axis of the region of interest (ROI) was set in segment 5 (pericholecystic area), and the control ROI in segment 8 at the same depth. The intensity ratio (IR) was defined as the peak intensity of segment 5 divided by the simultaneous value of segment 8. The characteristics of the patient with and without acute cholecystitis were compared. The correlation between the IR and the presence of acute cholecystitis was analyzed using binomial logistic regression analysis. A receiver operating characteristic (ROC) curve analysis was performed as well. RESULTS: The IR was significantly higher in the group with than without acute cholecystitis (p = 0.006). The IR correlated significantly with the presence of acute gallbladder inflammation (p = 0.043). The area under the ROC curve was estimated as 0.852 (95% confidence interval, 0.709-0.995). A cut-off value of 2.72 had a sensitivity of 81.8% and a specificity of 81.3%. CONCLUSIONS: The IR obtained by CEUS with time-intensity curve analysis generally demonstrated increased enhancement of the liver parenchyma adjacent to the inflamed gallbladder.