Neuromelanin Contrast Optimization and Improved Visualization of the Substantia Nigra in a 3D Gradient-Echo Sequence With Magnetization Transfer.

ABSTRACT: Neuromelanin (NM) magnetic resonance imaging has been used to evaluate the loss of melanized neurons in the substantia nigra, the main characteristic of Parkinson disease, typically by measuring the contrast ratio (CR) between the NM-rich areas and the cerebral peduncles in the midbrain. Neuromelanin contrast can be generated by employing a 3D gradient-echo (GRE) sequence with magnetization transfer (MT). In this work, we first evaluated the effect of the MT pulse frequency on the CR and contrast-to-noise ratio (CNR), analyzing a large frequency range from 500 to 100K Hz. Secondly, the impact of the 3D GRE sequence flip angle (FA) was evaluated using angles from 5° to 40°. Additionally, images were acquired both with and without MT for each FA, providing an opportunity to examine the effec

SUBMITTER: Andikoetxea BG 

PROVIDER: S-EPMC12364552 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature