Outcome of hypovascular hepatic nodules revealing no gadoxetic acid uptake in patients with chronic liver disease

Abstract

Purpose: To elucidate the natural history of hypovascular nodules that appear hypointense on hepatocyte-phase gadoxetic acid-enhanced MR images by focusing on hypervascularization over time. Materials and Methods:In this study, 135 hypovascular nodules revealing no gadoxetic acid uptake in 53 patients were examined. All nodules were retrospectively examined using serial follow-up computed tomography (CT) and MRI examinations until hypervascularity was observed on arterial-phase dynamic CT or gadoxetic acid-enhanced MR images, or on CT during hepatic arteriography. Logistic regression analysis was used to investigate the association between hypervascularization and MR findings including a presence of fat assessed by a signal drop on opposed-phase T1-weighted images.Results: Of the 135 nodules, 16 underwent hypervascularization. The size of the nodules and the presence of fat in the nodules were independent indicators of hypervascularization. The 1-year cumulative risk of hypervascularization was 15.6%. This risk was significantly increased in the case of nodules >10 mm (37.6%, P < 0.01) and fatcontaining nodules (26.5%, P < 0.01).Conclusion: Hypovascular nodules that appear hypointense on hepatocyte-phase gadoxetic acid-enhanced MR images may progress to conventional hypervascular hepatocellular carcinoma. Nodules more than 10 mm in diameter and containing fat are at high risk for developing hypervascularization.

Rules, Roles, and Room for Discussion in Gadoxetic Acid-enhanced Magnetic Resonance Liver Imaging: Current Knowledge and Future Challenges

“…80,81 If left untreated, more than 10z of these lesions will become hypervascular or conventional HCCs within a year. Among early HCCs identiˆed by gadoxetic acid-enhanced MR imaging, an especially important risk factor for hypervascularization is size exceeding 10 mm 87,88 (Fig. 9a-d).…”

Natural Course of Hypovascular Nodules Detected on Gadoxetic Acid-enhanced MR Imaging: Presence of Fat is a Risk Factor for Hypervascularization

“…28 Several recent studies have reported the hypervascularization of hypovascular nodules detected on gadoxetic acid-enhanced MR imaging. [17][18][19] Table 2 summarizes those study results and ours. One risk factor for hypervascularization is nodule size.…”

“…17 Because fatty changes in nodules are a characteristic histopathological feature of HGDN and early HCC 29,30 and a gradual decrease in OATP8 expression has been shown during multistep hepatocarcinogenesis, 27 it is reasonable to consider most hypovascular nodules with fat detected by gadoxetic acid-enhanced MR imaging to be HGDN or early HCC.…”

“…However, the management of these nodules is a contentious issue. Several recent studies have reported the detection of hypovascular nodules by gadoxetic acid-enhanced MR imaging, [17][18][19][20][21] though the occurrence of hypervascular HCC varied. For this reason, we believe that results from diŠerent groups of patients are important to identify a treatment or surveillance strategy for these small hypovascular nodules.…”

Surveillance, Diagnosis, Treatment, and Outcome of Liver Cancer in Japan

“…It is now known that when such nodules follow their natural course, many eventually become hypervascular and progress to classical hypervascular HCC [33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51]. For these reasons, it has recently become a reality in the diagnosis of early HCC that among existing imaging diagnostic modalities, EOB-MRI is achieving a level of diagnostic performance approaching that of liver pathology experts.…”