With a proper methodological framework, IVIM MRI can provide valuable information on tissue structure and microvasculature beneficial for the diagnosis of breast cancer lesions.

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MP2RAGE yields greater reproducibility and better tissue contrast than MPRAGE in deep GM. T1 maps derived from MP2RAGE were highly reliable. MP2RAGE is useful for measurement and analysis of deep GM.

Diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) are widely used models to infer microstructural features in the brain from diffusion-weighted MRI. Several studies have recently applied both models to increase sensitivity to biological changes, however, it remains uncertain how these measures are associated. Here we show that cortical distributions of DTI and NODDI are associated depending on the choice of b-value, a factor reflecting strength of diffusion weighting gradient. We analyzed a combination of high, intermediate and low b-value data of multi-shell diffusion-weighted MRI (dMRI) in healthy 456 subjects of the Human Connectome Project using NODDI, DTI and a mathematical conversion from DTI to NODDI. Cortical distributions of DTI and DTI-derived NODDI metrics were remarkably associated with those in NODDI, particularly when applied highly diffusion-weighted data (b-value = 3000 sec/mm 2 ). This was supported by simulation analysis, which revealed that DTI-derived parameters with lower b-value datasets suffered from errors due to heterogeneity of cerebrospinal fluid fraction and partial volume. These findings suggest that high b-value DTI redundantly parallels with NODDI-based cortical neurite measures, but the conventional low b-value DTI is hard to reasonably characterize cortical microarchitecture.

Highlights The Brain/MINDS beyond project plans to collect multi-site/scanner brain MRI data. Prospective harmonization of MRI was achieved by standardizing scanning protocols. The preliminary data showed moderate reliability of brain connectome data. Completing traveling subject plan will allow robust statistical harmonization. Scanning protocols are publicly available and data will also be shared by 2024.