Purpose: The purpose of this study was to compare the accuracy of diffusionweighted imaging (DWI) visual analysis (VA) versus the apparent diffusion coefficient quantification (ADC-Q) in assessing malignancy of solid focal liver lesions (FLLs). Material and Methods: Two radiologists in consensus retrospectively assessed as benign or malignant 50 FLLs (16 benign, 24 malignant) on 32 patients examined on a 1.5 T. Two different methods were used in separate reading sessions: (a) VA of signal intensity on DWI images at b=800 sec/mm2 and ADC-map; (b) lesion ADC measurement on the ADC-map. Reference standard included histology and follow-up confirmation of a consensus panel diagnosis. We estimated the accuracy for malignancy of both methods and the ADC-Q threshold as assessed by a receiver operating characteristic (ROC) analysis. Results: Because of 20 false-negative hepatocarcinoma, VA showed lower accuracy than ADC-Q (52.0% vs. 68.0%). However, stratified accuracy for metastases was higher than VA (75.0 vs. 66.7%). ADCs and signal features of malignant and benign FLLs largely overlapped. Conclusion: VA performed worse than ADC-Q for hepatocarcinoma, and better for metastases, possibly in relation with the T2-shine-through phenomenon. Overall, the accuracy of both methods was limited because of the overlap in visual appearance and ADC values between solid benign and malignant FLLs.

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

GIROMETTI, Rossano;BAZZOCCHI, Massimo;ZUIANI, Chiara
2012

Abstract

Purpose: The purpose of this study was to compare the accuracy of diffusionweighted imaging (DWI) visual analysis (VA) versus the apparent diffusion coefficient quantification (ADC-Q) in assessing malignancy of solid focal liver lesions (FLLs). Material and Methods: Two radiologists in consensus retrospectively assessed as benign or malignant 50 FLLs (16 benign, 24 malignant) on 32 patients examined on a 1.5 T. Two different methods were used in separate reading sessions: (a) VA of signal intensity on DWI images at b=800 sec/mm2 and ADC-map; (b) lesion ADC measurement on the ADC-map. Reference standard included histology and follow-up confirmation of a consensus panel diagnosis. We estimated the accuracy for malignancy of both methods and the ADC-Q threshold as assessed by a receiver operating characteristic (ROC) analysis. Results: Because of 20 false-negative hepatocarcinoma, VA showed lower accuracy than ADC-Q (52.0% vs. 68.0%). However, stratified accuracy for metastases was higher than VA (75.0 vs. 66.7%). ADCs and signal features of malignant and benign FLLs largely overlapped. Conclusion: VA performed worse than ADC-Q for hepatocarcinoma, and better for metastases, possibly in relation with the T2-shine-through phenomenon. Overall, the accuracy of both methods was limited because of the overlap in visual appearance and ADC values between solid benign and malignant FLLs.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11390/872640
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