The Role of Parallel Diffusion-Weighted Imaging and Apparent Diffusion Coefficient (ADC) Map Values for Evaluating Breast Lesions:

Rationale and Objectives

To evaluate the feasibility of using diffusion-weighted imaging (DWI) with an array spatial sensitivity encoding technique (ASSET) and apparent diffusion coefficient (ADC) map values with different b values to distinguish benign and malignant breast lesions.

Materials and Methods

Fifty-six female patients with 60 histologically proven breast lesions and 20 healthy volunteers underwent magnetic resonance imaging. A subset of normal volunteers (n = 7) and patients (n = 16) underwent both conventional DWI and ASSET-DWI, and the image quality between the two methods was compared. Finally, ASSET-DWI with b = 0, 600 s/mm², and b = 0, 1000 s/mm², were compared for their ability to distinguish benign and malignant breast lesions.

Results

The ASSET-DWI method had less distortion, fewer artifacts, and a lower acquisition time than other methods. No significant difference (P > .05) was detected in ADC map values between ASSET-DWI and conventional DWI. For ASSET-DWI, the sensitivity of ADC values for malignant lesions with a threshold of less than 1.44 × 10⁻³ mm²/s (b = 600 s/mm²) and 1.18 × 10⁻³ mm²/s (b = 1000 s/mm²) was 80% and 77.5%, respectively. The specificity of both groups was 95%.

Conclusion

ASSET-DWI evaluation of breast tissue offers decreased distortion, susceptibility to artifacts, and acquisition time relative to other methods. The use of ASSET-DWI is feasible with b values ranging from 600 to 1000 s/mm² and provides increased specificity compared to other techniques. Thus, the ADC value of a breast lesion can be used to further characterize malignant lesions from benign ones.

Key Words: Diffusion-weighted imaging (DWI), MRI, breast carcinoma, apparent diffusion coefficient (ADC) map