High-flow haemangiomas versus hypervascular hepatocellular carcinoma showing "pseudo-washout" on gadoxetic acid-enhanced hepatic MRI: value of diffusion-weighted imaging in the differential diagnosis of small lesions. Issue 3 (March 2017)

• Record Type: Journal Article
• Authors: Nam, S.J.; Yu, J.-S.; Cho, E.-S.; Kim, J.H.; Chung, J.-J.
• Is Part Of: Clinical radiology. Volume 72:Issue 3(2017)
• Page Start: 247
• Page End: 254
• Publication Date: 2017-03
• Subjects: Medical radiology -- Periodicals; Radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiology -- Periodicals; Societies, Medical -- Periodicals; Medical radiology; Radiotherapy; Electronic journals; Periodicals; 616.0757
• DOI: 10.1016/j.crad.2016.09.020
• Languages: English
• ISSNs: 0009-9260

Abstract

Abstract : Aim: To validate the usefulness of diffusion-weighted imaging (DWI) in the differentiation of high-flow haemangiomas showing pseudo-washout appearance on gadoxetic acid-enhanced hepatic MRI from small hypervascular hepatocellular carcinomas (HCCs). Materials and methods: DWI (b=50, 800 s/mm 2 ) with apparent diffusion coefficient (ADC) maps for 50 haemangiomas (6.4±2.9 mm) showing intense enhancement on arterial dominant phase imaging and hypointensity on transitional and/or hepatobiliary phase imaging during gadoxetic acid-enhanced MRI were retrospectively analysed and compared with that of 113 hypervascular HCCs (12.8±3.7 mm). In addition to measurement of mean ADC values on DWI and contrast-to-noise ratio (CNR) on corresponding T2-weighted imaging, qualitative analysis of DWI was performed for each lesion by two independent observers using a five-point scale. Results: Both of mean ADC value (1.902 versus 0.997×10 −3 mm 2 /s) and mean CNR (119.2 versus 36.9) for haemangioma were significantly larger than for HCC ( p <0.001). On receiver operating characteristic (ROC) analysis, an area under the curve (AUC) of 0.995 for ADC values was significantly larger than 0.915 for CNRs ( p =0.002). When the ADC value of 1.327×10 −3 mm 2 /s was used as the threshold for the diagnosis of haemangioma, the sensitivity and specificity were 98% and 97.3%, respectively. The mean sensitivity and specificity of qualitative analysis for the differentiation of haemangioma from HCC were 92% and 99.1%, respectively. Conclusion: For high-flow small haemangiomas showing pseudo-washout appearance during gadoxetic acid-enhanced hepatic MRI, high b-factor DWI including an ADC map may provide additional information to enhance the confidence to exclude small hypervascular HCCs. Highlights: We compared the ADC values of high-flow haemangiomas with hypervascular HCCs. The ADC values of haemangiomas were significantly higher than those of HCCs. High ADC difference on DWI was larger than CNR difference on T2wI between two diseases. The high ADC could enhance the confidence of diagnosis of high-flow haemangiomas excluding HCC.