The number in the title is misleading but what you write here is also misleading. > The diffusion tensor images (DTI) @ 15 μm spatial resolution are 1,000 time

The number in the title is misleading but what you write here is also misleading. > The diffusion tensor images (DTI) @ 15 μm spatial resolution are 1,000 times the resolution of most preclinical rodent DTI/MRI. Superresolution track density images are 27,000 times that of typical preclinical DTI/MRI. The resolution of the raw MRI images is significantly higher, without that increased resolution it would be impossible to align the light sheet images. The light sheet images are not use to "improve" MRI resolution.