Skip to content

T1w-Only Model Requirements

MRI Requirements: T1w-Only Model

Overview

This page describes the MRI data requirements for the HyperASHS PMC_T1_Atlas model, which uses only T1-weighted MRI. This model segments the hippocampus (anterior and posterior), the amygdala and the extrahippocampal medial temporal lobe subregions: entorhinal cortex (ERC), Brodmann areas 35 and 36 (BA35, BA36) and parahippocampal cortex (PHC). Like ASHS-PMC-T1, it also labels the dura mater, which has similar intensity to gray matter in 3T T1-weighted MRI.

This model does not segment hippocampal subfields, because 3T T1-weighted MRI does not have enough contrast and resolution to resolve them. High-resolution T2-weighted MRI and a T2w + T1w model are required for that.

The T1w-only model uses the same segmentation protocol as the T2w + T1w PMC_Atlas model, so measures of the MTL cortex can be compared between participants scanned with and without T2w MRI.

MRI requirements

Your data should meet these specifications:

  • T1-weighted MRI (e.g., MPRAGE):
    • voxel size of about 1.0 mm × 1.0 mm × 1.0 mm or finer
    • whole brain coverage, not skull stripped
  • 3 Tesla field strength

In addition, the model was trained on older adults (55+) and is intended for studies of aging and neurodegenerative disease.

T1-weighted input image

Coronal slice of T1-weighted MRI suitable for the PMC_T1_Atlas model.

PMC_T1_Atlas segmentation

HyperASHS segmentation with the PMC_T1_Atlas model.

Using classic ASHS? See the equivalent page for ASHS Classic.