Contrast-enhanced US Approach to the Diagnosis of Focal Liver Masses

Abstract

Focal liver lesions are commonly encountered and often demonstrate nonspecific findings at initial imaging. Although most incidentally discovered liver lesions are benign, their noninvasive diagnosis is necessary, especially if they are large or atypical. Imaging characterization of focal liver lesions and exclusion of malignancy are of prime importance, particularly in high-risk populations. Contrast agent-enhanced ultrasonography of liver lesions is both accurate and reproducible for evaluation of benign and malignant liver tumors. Use of an imaging algorithm and a controlled sonographic technique, including dedicated arterial phase cine imaging and imaging every 30 seconds in the portal venous phase and the delayed (or late) phase, is essential for accurate characterization. This algorithmic analysis of focal liver lesions focuses first on the determination of malignancy by imaging the portal venous phase and the late phase; washout in these phases correlates with a malignant tumor, and sustained enhancement in these phases is suggestive that a lesion is benign. In addition, the timing and the intensity of washout differentiate hepatocellular malignancies from nonhepatocellular malignancies. Nonhepatocellular tumors demonstrate early and strong washout, whereas hepatocellular malignancies show delayed and weak washout. Subsequent analysis of dynamic real-time enhancement patterns in the arterial phase demonstrates specific enhancement patterns of common benign and malignant focal liver lesions. Hemangiomas show classic peripheral nodular enhancement, and spoke-wheel centrifugal enhancement is suggestive of focal nodular hyperplasia. Hepatic adenomas may show centripetal filling. However, arterial phase enhancement in malignancy has less specificity. Online supplemental material is available for this article. RSNA, 2017 •.

Hepatic hemangioma supplied by abnormal portal vein: A case report

“…Diagnosis of hepatic hemangioma can be easily made using CEUS, CT, or MRI with recognition of the fill‐in pattern or peripheral globular enhancement during the portal venous phase . CEUS also depict progressive peripheral nodular enhancement with centripetal progression, occurring rapidly or slowly in a typical hemangioma . Abdominal angiography shows a cotton‐wool appearance in the early phase of the disease .…”

“…In the present case, the abnormal portal vein demonstrated by CEUS supports this hypothesis. CEUS has high spatial and temporal resolution and high sensitivity to detect blood flow . Hence, it could detect the abnormal vessel.…”

“…4 CEUS also depict progressive peripheral nodular enhancement with centripetal progression, occurring rapidly or slowly in a typical hemangioma. 3 Abdominal angiography shows a cotton-wool appearance in the early phase of the disease. 2 Arterial portography and CTAP reportedly showed no enhancement within the hemangioma.…”

“…CEUS has high spatial and temporal resolution and high sensitivity to detect blood flow. 3 Hence, it could detect the abnormal vessel. The presence of Elastic fibers confirmed by EVG staining was also compatible with the presence of an abnormal vein in the hemangioma.…”

“…It is typically supplied by the hepatic artery. Abdominal angiography, contrast‐enhanced ultrasonography (CEUS), contrast‐enhanced computed tomography (CT), and contrast‐enhanced magnetic resonance imaging (MRI) have clearly demonstrated blood supply to the hemangioma during the arterial phase. Only a few cases of hepatic hemangioma have been reported to be supplied by the portal vein .…”