Contrast-enhanced ultrasound in gallbladder disease: a pictorial review.

With its excellent contrast and spatial resolution, and the ability to image in real-time, ultrasound is the main imaging modality for assessing the gallbladder (GB). The application of contrast-enhanced ultrasound (CEUS) of the GB is now increasingly recognized as a useful addition to ultrasound and other cross-sectional imaging in the assessment of neoplastic and non-neoplastic GB disease. With the ability to image microcirculation and optimal contrast resolution, CEUS allows high-quality delineation in real-time, allowing for increased diagnostic confidence. In addition, ultrasound contrast agents have a favorable safety profile and can be used if CT or MR contrast agents are contraindicated or undesired. In this review, the CEUS appearances of a range of GB diseases encountered are presented, including adenomyomatosis, polyps, carcinoma, sludge, and cholecystitis with mural ulceration or perforation.

Ultrasound in chronic liver disease.

BACKGROUND: With the high prevalence of diffuse liver disease there is a strong clinical need for noninvasive detection and grading of fibrosis and steatosis as well as detection of complications. METHODS: B-mode ultrasound supplemented by portal system Doppler and contrast-enhanced ultrasound are the principal techniques in the assessment of liver parenchyma and portal venous hypertension and in hepatocellular carcinoma surveillance. RESULTS: Fibrosis can be detected and staged with reasonable accuracy using Transient Elastography and Acoustic Radiation Force Imaging. Newer elastography techniques are emerging that are undergoing validation and may further improve accuracy. Ultrasound grading of hepatic steatosis currently is predominantly qualitative. CONCLUSION: A summary of methods including B-mode, Doppler, contrast-enhanced ultrasound and various elastography techniques, and their current performance in assessing the liver, is provided. TEACHING POINTS: • Diffuse liver disease is becoming more prevalent and there is a strong clinical need for noninvasive detection. • Portal hypertension can be best diagnosed by demonstrating portosystemic collateral venous flow. • B-mode US is the principal US technique supplemented by portal system Doppler. • B-mode US is relied upon in HCC surveillance, and CEUS is useful in the evaluation of possible HCC. • Fibrosis can be detected and staged with reasonable accuracy using TE and ARFI. • US detection of steatosis is currently reasonably accurate but grading of severity is of limited accuracy.

Diagnostic performance of MDCT, PET/CT and gadoxetic acid (Primovist(®))-enhanced MRI in patients with colorectal liver metastases being considered for hepatic resection: initial experience in a single centre.

PURPOSE: To compare the relative diagnostic performance of MDCT, PET/CT and Primovist-enhanced MRI (P-MRI) in the pre-resection work-up of colorectal cancer (CRC) liver metastases. METHOD AND MATERIALS: This was a retrospective study of consecutive referrals for CRC liver metastases. All patients had MDCT, PET/CT and P-MRI examinations within 3 months of each other. They were divided into 2 groups: resected and unresected. Patients in the resected group underwent liver resection within 3 months of the imaging studies. In the unresected group, patients were unresectable by imaging criteria or are awaiting surgery. Standard of reference (SOR) was intra-operative ultrasound findings and pathology for the resected group. Intermodality comparison was the SOR for the unresected group. Number of lesions identified by each imaging modality for each patient was recorded. Sensitivity (95% CI) and PPV were calculated for each imaging modality in the resected group. RESULTS: There were 19 patients in the resected group and 11 patients in the unresected group. The sensitivity (96%) and PPV (0.91) of P-MRI were both superior to that of MDCT (P = 0.0009) and PET/CT (P = 0.0003). Intermodality comparison showed that P-MRI detected more lesions than MDCT and PET/CT. CONCLUSION: The sensitivity and PPV of P-MRI was superior to that of MDCT and PET/CT. P-MRI probably has the most added value if used after MDCT and PET/CT in patients still considered eligible for liver resection.