Korean J Radiol.  2020 Sep;21(9):1036-1044. 10.3348/kjr.2019.0568.

Feasibility Study of Synthetic Diffusion-Weighted MRIin Patients with Breast Cancer in Comparison withConventional Diffusion-Weighted MRI

• Choi BH
• Baek HJ
• Ha JY
• Ryu KH
• Moon JI
• Park SE
• Bae K
• Jeon KN
• Jung EJ

• KMID: 2505744
• DOI: http://doi.org/10.3348/kjr.2019.0568

Abstract

Objective
To investigate the clinical feasibility of synthetic diffusion-weighted imaging (sDWI) at different b-values in patientswith breast cancer by assessing the diagnostic image quality and the quantitative measurements compared with conventionaldiffusion-weighted imaging (cDWI).
Materials and Methods
Fifty patients with breast cancer were assessed using cDWI at b-values of 800 and 1500 s/mm² (cDWI₈₀₀and cDWI₁₅₀₀) and sDWI at b-values of 1000 and 1500 s/mm² (sDWI₁₀₀₀ and sDWI₁₅₀₀). Qualitative analysis (normal glandulartissue suppression, overall image quality, and lesion conspicuity) was performed using a 4-point Likert-scale for all DWI setsand the cancer detection rate (CDR) was calculated. We also evaluated cancer-to-parenchyma contrast ratios for each DWI setin 45 patients with the lesion identified on any of the DWI sets. Statistical comparisons were performed using Friedman test,one-way analysis of variance, and Cochran’s Q test.
Results
All parameters of qualitative analysis, cancer-to-parenchyma contrast ratios, and CDR increased with increasingb-values, regardless of the type of imaging (synthetic or conventional) (p< 0.001). Additionally, sDWI₁₅₀₀ provided better lesionconspicuity than cDWI₁₅₀₀ (3.52 ± 0.92 vs. 3.39 ± 0.90, p< 0.05). Although cDWI₁₅₀₀ showed better normal glandular tissuesuppression and overall image quality than sDWI₁₅₀₀ (3.66 ± 0.78 and 3.73 ± 0.62 vs. 3.32 ± 0.90 and 3.35 ± 0.81, respectively;p< 0.05), there was no significant difference in their CDR (90.0%). Cancer-to-parenchyma contrast ratios were greater insDWI₁₅₀₀ than in cDWI₁₅₀₀ (0.63 ± 0.17 vs. 0.55 ± 0.18, p< 0.001).
Conclusion
sDWI₁₅₀₀ can be feasible for evaluating breast cancers in clinical practice. It provides higher tumor conspicuity,better cancer-to-parenchyma contrast ratio, and comparable CDR when compared with cDWI₁₅₀₀.

Keyword

Breast cancer; b-value; Diffusion-weighted imaging; MRI; Synthetic MRI