Diagnostic Usefulness of Combination of Diffusion-weighted Imaging and T2WI, Including Apparent Diffusion Coefficient in Breast Lesions: Assessment of Histologic Grade

Acad Radiol. 2018 May;25(5):643-652. doi: 10.1016/j.acra.2017.11.011. Epub 2018 Jan 12.

Abstract

Purpose: This study aimed to compare the diagnostic values of a combination of diffusion-weighted imaging and T2-weighted imaging (DWI-T2WI) with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and to evaluate the correlation of DWI with the histologic grade in breast cancer.

Materials and methods: This study evaluated a total of 169 breast lesions from 136 patients who underwent both DCE-MRI and DWI (b value, 1000s/mm2). Morphologic and kinetic analyses for DCE-MRI were classified according to the Breast Imaging-Reporting and Data System. For the DWI-T2WI set, a DWI-T2WI score for lesion characterization that compared signal intensity of DWI and T2WI (benign: DWI-T2WI score of 1, 2; malignant: DWI-T2WI score of 3, 4, 5) was used. The diagnostic values of DCE-MRI, DWI-T2WI set, and combined assessment of DCE and DWI-T2WI were calculated.

Results: Of 169 breast lesions, 48 were benign and 121 were malignant (89 invasive ductal carcinoma, 24 ductal carcinoma in situ, 4 invasive lobular carcinoma, 4 mucinous carcinoma). The mean apparent diffusion coefficient (ADC) of invasive ductal carcinoma (0.92 ± 0.19 × 10-3 mm2/s) and ductal carcinoma in situ (1.11 ± 0.13 × 10-3 mm2/s) was significantly lower than the value seen in benign lesions (1.36 ± 0.22 × 10-3 mm2/s). The specificity, positive predictive value (PPV), and accuracy of DWI-T2WI set and combined assessment of DCE and DWI-T2WI (specificity, 87.5% and 91.7%; PPV, 94.3% and 96.2%; accuracy, Az = 0.876 and 0.922) were significantly higher than those of the DCE-MRI (specificity, 45.8%; PPV, 81.7%; accuracy, Az = 0.854; P < .05). A low ADC value and the presence of rim enhancement were associated with a higher histologic grade cancer (P < .05).

Conclusion: Combining DWI, T2WI, and ADC values provides increased accuracy for differentiation between benign and malignant lesions, compared with DCE-MRI. A lower ADC value was associated with a higher histologic grade cancer.

Keywords: Breast cancer; apparent diffusion coefficient; diffusion-weighted imaging; magnetic resonance imaging.

Publication types

  • Comparative Study

MeSH terms

  • Adenocarcinoma, Mucinous / diagnostic imaging*
  • Adenocarcinoma, Mucinous / pathology
  • Adult
  • Aged
  • Breast Neoplasms / diagnostic imaging*
  • Breast Neoplasms / pathology
  • Carcinoma, Ductal, Breast / diagnostic imaging*
  • Carcinoma, Ductal, Breast / pathology
  • Carcinoma, Intraductal, Noninfiltrating / diagnostic imaging*
  • Carcinoma, Intraductal, Noninfiltrating / pathology
  • Carcinoma, Lobular / diagnostic imaging*
  • Carcinoma, Lobular / pathology
  • Contrast Media
  • Diagnosis, Differential
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Humans
  • Middle Aged
  • Neoplasm Grading
  • Predictive Value of Tests

Substances

  • Contrast Media