Accuracy of visual assessment versus apparent diffusion coefficient quantification in differentiating malignant and solid benign focal liver lesions with diffusion-weighted imaging

摘要

Purpose: The purpose of this study was to compare the accuracy of diffusionweightedimaging (DWI) visual analysis (VA) versus the apparent diffusioncoefficient quantification (ADC-Q) in assessing malignancy of solid focal liverlesions (FLLs).Material and Methods: Two radiologists in consensus retrospectivelyassessed as benign or malignant 50 FLLs (16 benign, 24 malignant) on 32patients examined on a 1.5 T. Two different methods were used in separatereading sessions: (a) VA of signal intensity on DWI images at b=800 sec/mm2and ADC-map; (b) lesion ADC measurement on the ADC-map. Referencestandard included histology and follow-up confirmation of a consensus paneldiagnosis. We estimated the accuracy for malignancy of both methods and theADC-Q threshold as assessed by a receiver operating characteristic (ROC)analysis.Results: Because of 20 false-negative hepatocarcinoma, VA showed loweraccuracy than ADC-Q (52.0% vs. 68.0%). However, stratified accuracy formetastases was higher than VA (75.0 vs. 66.7%). ADCs and signal features ofmalignant and benign FLLs largely overlapped.Conclusion: VA performed worse than ADC-Q for hepatocarcinoma, andbetter for metastases, possibly in relation with the T2-shine-throughphenomenon. Overall, the accuracy of both methods was limited because ofthe overlap in visual appearance and ADC values between solid benign andmalignant FLLs.