Intravoxel incoherent motion (IVIM) and non-Gaussian diffusion MRI of the lactating breast

Mami Iima; Masako Kataoka; Rena Sakaguchi; Shotaro Kanao; Natsuko Onishi; Makiko Kawai; Akane Ohashi; Katsutoshi Murata; Kaori Togashi

doi:10.1016/j.ejro.2018.01.003

Intravoxel incoherent motion (IVIM) and non-Gaussian diffusion MRI of the lactating breast

Eur J Radiol Open. 2018 Feb 2:5:24-30. doi: 10.1016/j.ejro.2018.01.003. eCollection 2018.

Authors

Mami Iima^{1

2}, Masako Kataoka¹, Rena Sakaguchi¹, Shotaro Kanao¹, Natsuko Onishi¹, Makiko Kawai¹, Akane Ohashi¹, Katsutoshi Murata³, Kaori Togashi¹

Affiliations

¹ Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
² The Hakubi Center for Advanced Research, Kyoto University, Kyoto, Japan.
³ Siemens Japan K.K., Shinagawa, Tokyo, Japan.

Abstract

Purpose: To investigate the effect of breastfeeding on IVIM and non-Gaussian diffusion MRI in the breast.

Materials and methods: An IRB approved prospective study enrolled seventeen volunteers (12 in lactation and 5 with post-weaning, range 31-43 years; mean 35.4 years). IVIM (f_IVIM and D*) and non-Gaussian diffusion (ADC₀ and K) parameters using 16 b values, plus synthetic apparent diffusion coefficients (sADCs) from 2 key b values (b = 200 and 1500 s/mm²) were calculated using regions of interest. ADC₀ maps of the whole breast were generated and their contrast patterns were evaluated by two independent readers using retroareolar and segmental semi-quantitative scores. To compare the diffusion and IVIM parameters, Wilcoxon signed rank tests were used between pre- and post-breastfeeding and Mann-Whitney tests were used between post-weaning and pre- or post-breastfeeding.

Results: ADC₀ and sADC values significantly decreased post-breastfeeding (1.90 vs. 1.72 × 10^-3 mm²/s, P < 0.001 and 1.39 vs. 1.25 × 10^-3 mm²/s, P < 0.001) while K values significantly increased (0.33 vs. 0.44, P < 0.05). f_IVIM values significantly increased after breastfeeding (1.97 vs. 2.97%, P < 0.01). No significant difference was found in D* values. There was significant heterogeneity in ADC₀ maps post-breastfeeding, both in retroareolar and segmental scores (P < 0.0001 and =0.0001).

Conclusion: IVIM and non-Gaussian diffusion parameters significantly changed between pre- and post-breastfeeding status, and care needs to be taken in interpreting diffusion-weighted imaging (DWI) data in lactating breasts.

Keywords: ADC, apparent diffusion coefficient; Breast; DCE-MRI, dynamic contrast-enhanced MRI; DWI, diffusion-weighted imaging; Diffusion-weighted imaging; IVIM, intravoxel incoherent motion; Intravoxel incoherent motion; K, kurtosis; Kurtosis; Lactation; MD, mean diffusion; NCCN, national comprehensive cancer network; PABC, pregnancy-associated breast cancer; ROI, regions of interest; T1WI, T1-weighted images; T2WI, T2-weighted images.