T1 MRI Sequence

An overview of the T1 Magnetic Resonance Imaging (MRI) sequence on the brain.

• Description of contrast of the T1

• Imaging orientations

• What can be measured when using the T1

  • Research Usage

• Pathology that can be seen on T1

• Software that can used to analyze the T1

• Resources

Description/ Orientation

Fluid such as, CSF (cerebral spinal fluid), is usually dark on this image. Grey Matter (GM) appears dark and white matter (WM) appears brighter on T1.

Axial views of a T1 image. The image on the right is a more superior slice of the the one on the left.

The image on the left is a sagittal view and the image on the right is a coronal view of the T1.

Recognition

• Grey Matter (Cortex and subcortical structures): dark grey

• White Matter: Lighter (hyperintensed)

• Bone: Dark

• Fat: Bright (hyperintensed)

• Fluid is dark

• New blood is bright

• Short repetition time (TR)

• Short echo time (TE)

Usage (When can be measured when using the T1)

• Used to visualize anatomical details

• Vascular changes (depends on the lesion, this can appear dark, or bright when viewing new blood)

• Disruption of the BBB (Usually Gadolinium (Gd) Enhanced)

Research Usage

• Anatomical Segmentation

• Segmentation of hypointensities

• Cortical Thickness

• Cortical Thinning (longitudinally)

Software used for analysis

1. FreeSurfer

2. Statistical Parametric Mapping (SPM)

3. 3D Slicer

Resources

• Radiopaedia (MRI Sequences (Overview))