Small Focal Hepatic Lesions <=1 cm: Their Detection and Characterization with Performing Diffusion-Weighted Sensitivity-Encoding versus SPIO-Enhanced 3T MR Imaging

ABSTRACT

PURPOSE: We wanted to compare the accuracy of 3T DW-SENSE imaging with that of SPIO-enhanced imaging for the detection and characterization of small hepatic lesions. MATERIALS AND METHODS: 124 focal hepatic lesions of 42 patients were retrospectively reviewed. The DW-SENSE imaging and four T2-weighted imaging, including the respiratory-triggered and breath-hold fast spin-echo images, the half-fourier single-shot turbo spin-echo images and the T2*-weighted fast field-echo images, were acquired. Four T2-weighted examinations were performed after administering SPIO. The images were divided into two sets the SPIO image set (four pre- and post-contrast T2-weighted images) and the DW-SENSE image set (four DW-SENSE and pre-contrast T2-weighted images). These were sorted according to the confidence levels for lesion detection and characterization into four and five grades. The ROC curve (Az) was calculated. RESULTS: The detection accuracy with using the DW-SENSE image set (Az=0.932, 0.889) was higher than with using the SPIO image set (Az=0.852, 0.798) for all the lesions and the small lesions (<= 1 cm) (p < 0.05). For lesion characterization, the accuracy with using the DW-SENSE image set (Az=0.934, 0.896) was higher than that with using the SPIO image set (Az=0.914, 0.882) for all the lesions and the small lesion, but this was not statistically significant. CONCLUSION: The 3T MR DW-SENSE image set showed higher accuracy for the detection of small hepatic lesions than the SPIO image set.