Supplement value of magnetic resonance imaging in small hepatic lesion (< or = 20 mm) detected on routine computed tomography

To determine the supplemental MRI value in characterization of small hepatic lesions (< or = 20 mm) indetermined by routine CT scan.

This was a retrospective study. Sixty-four patients with 81 indeterminate small hepatic lesions on the CT scan were included in this study. Two radiologists simultaneously evaluated the CT scan, followed by MRI. Patient history, imaging record, and final diagnosis were blinded. Final diagnoses were made by interpretation of all medical data and defined these lesions as benign or malignancy by using either histology or follow-up imaging combined with laboratory data.

In 64 patients, 62 lesions (76.5%) of 81 indeterminate lesions were benign, whereas 19 lesions (23.5%) were malignant. MRI interpreted 55 lesions as benign, 17 lesions as malignant, and 9 as indeterminate lesions. If the indeterminate lesions were assumed as benign lesions, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), are 68.4%, 93.6%, 76.5%, and 90.6%, respectively.

MRI can supplement CT scan in characterization of small hepatic lesion with high specificity and accuracy.