In vivo quantification of T₁, T₂, and apparent diffusion coefficient in the mouse retina at 11.74T

MRI has recently been used for noninvasive examination of retinal structure and function in rats and cats. However, the advantages of quantitative high-resolution MRI of retina from mice have not yet been explored. In the present study, T₁ and T₂ relaxation time constants and the directional apparent diffusion coefficient (ADC) in the retina of C57/BL6 mice were measured. Three MR-detected retina layers and a MR-detected choroid layer were observed on both T₁- and T₂-weighted images at an image resolution of 47 x 47 x 400 μm³. The significantly higher ADC parallel to than that perpendicular to the optic nerve in the MR-detected outer retina layer at the central retina reflects the known cellular organization of the photoreceptor cells. This study establishes, for the first time, normative metrics of T₁, T₂, and ADC of the mouse retina. These MR parameters are expected to be useful in future evaluation of developmental and pathological alterations of retinal cell layers in mice.