Comparing Lesion Conspicuity and ADC Reliability in High-resolution Diffusion-weighted Imaging of the Breast

Purpose: This study investigated the breast lesion conspicuity and apparent diffusion coefficient (ADC) reliability for three different diffusion-weighted imaging (DWI) protocols: spatiotemporal encoding (SPEN), single-shot echo-planar imaging (SS-EPI), and readout segmentation of long variable echo-trains (RESOLVE). Methods: Sixty-five women suspected of having breast tumors were included in this study, with 44 lesions (36 malignant, 8 benign) analyzed further. Breast MRI was performed on a 3 Tesla (3T) system (MAGNETOM Prisma, Siemens) equipped with a dedicated 18-channel breast array coil for a phantom and patients. Three DWI protocols-SPEN, SS-EPI, and RESOLVE-were used. SS-EPI was acquired with an in-plane resolution of 2 x 2 mm(2), a slice thickness of 3 mm, and b-values of 0 and 1000 s/mm(2). SPEN had a higher in-plane resolution of 1 x 1 mm(2), a slice thickness of 1.5 mm, and b-values of 0, 850, and 1500 s/mm(2). RESOLVE was acquired with an in-plane resolution of 1 x 1 mm(2), a slice thickness of 1.5 mm, and b-values of 0 and 850 s/mm(2). Lesion conspicuity and ADC values were evaluated. Results: The average lesion conspicuity scores were significantly higher for RESOLVE (3.54 +/- 0.65) than for SPEN (3.07 +/- 0.91) or SS-EPI (2.48 +/- 0.78) (P < 0.01). The SPEN score was significantly higher than the SS-EPI score (P < 0.01). Phantom measurements indicated marginally lower ADC values for SPEN compared to SS-EPI and RESOLVE across all concentrations. The results revealed that SPEN (b = 0, 850, 1500 sec/mm(2)) yielded significantly lower ADC values compared to SPEN (b = 0, 850 sec/mm(2)) in malignant lesions (P < 0.01), with no significant difference observed between SPEN (b = 0, 850 sec/mm(2)), SS-EPI, and RESOLVE. For benign lesions, no significant difference in ADC values was found between SPEN (b = 0, 850 sec/mm(2)), SPEN (b = 0, 850, 1500 sec/mm(2)), SS-EPI, and RESOLVE. Conclusion: RESOLVE provided the highest lesion conspicuity, and ADC values in breast lesions were not significantly different among sequences ranging b values 850-1000 sec/mm(2). SPEN with higher b-values (0, 850, 1500 vs. 0, 850 sec/mm(2)) yielded significantly lower ADC values in malignant lesions, highlighting the importance of b-value selection in ADC quantification.