Diffusion-weighted imaging with fat suppression using short-tau inversion recovery: Clinical utility for diagnosis of breast lesions.

AIM

To compare the utility of conventional diffusion-weighted imaging (DWI) with fat suppression using short-tau inversion recovery (STIR-DWI) for the detection of breast lesions.

MATERIALS AND METHODS

Magnetic resonance imaging (MRI) images of 56 patients (both DWI and STIR-DWI performed) were retrospectively analysed. Parameters compared between DWI and STIR-DWI were image artefacts, image signal-to-noise ratio (SNR), apparent diffusion coefficient (ADC), and contrast-to-noise ratio (CNR). Diagnostic utility was assessed using receiver operating characteristic (ROC) analysis.

RESULTS

No abnormality was detected in 17 patients, with lesions observed in 39 patients (16 benign, 23 malignant; confirmed by biopsy or surgical histopathology). The rate of image artefacts was significantly lower for STIR-DWI (p < 0.01): quality levels 1 (best), 2, and 3 accounted for 50%, 35.7%, and 14.3% of DWI images, and 96.4%, 3.6% and 0% of STIR-DWI images, respectively. The SNR was not significantly different. ADC values of breast lesions and normal glands were significantly lower for DWI than for STIR-DWI (p = 0.03 and 0.034). ADC values of malignant lesions, but not benign lesions, were significantly lower for DWI than for STIR-DWI (p = 0.02). CNR values of both benign and malignant lesions were not significantly different between DWI and STIR-DWI. The area under the ROC curve, for the use of ADC values to differentiate benign from malignant lesions, was not significantly different between DWI (0.931) and STIR-DWI (0.914). Taking a threshold ADC value of 1.23 × 10(-3) mm(2)/s, the sensitivity and specificity were 87.5% and 87% for DWI, and 87.5% and 82.6% for STIR-DWI, respectively.

CONCLUSION

STIR-DWI is adequate for clinical use in breast MRI investigations.