Background and objective: Diffusion-weighted imaging has an emerging role for assessment
of focal and diffuse liver diseases. The aim of this study was to evaluate the diagnostic
performance of DWI for characterization of focal liver lesions (FLLs).
Patients and methods: This prospective study included 40 consecutive patients with 64 focal
liver lesions, who underwent MRI of the liver. All patients had one or more hepatic focal
lesion of diameter more than 1 cm. DWI was reviewed (b values of 0, 50 and 600 s/mm2)
and the mean ADC was calculated.
Results: Quantitative assessment using ADC map was more accurate (87.5%) than qualitative
assessment using DWI (75%) in characterization of FLLs. Mean ADC values of malignant
lesions (0.94 + 0.32 103 mm2/s) were significantly lower than those of benign lesions
(2.64 + 0.46 103 mm2/s), (P < 0.001). Using an ADC value above 1.6 103 mm2/s
offered the best accuracy in differentiation of malignant from benign lesions (86%).
Conclusion: DWI is a useful tool for FLLs characterization. Because of its known pitfalls and
limitations, mainly the considerable overlap of ADCs values between solid benign and
malignant lesions, it should be interpreted in combination with clinical data and conventional
MRI sequences.