Clinical T1-Weighted Brain Imaging at Ultra-High Field Using M2PRAGE: Application to Multiple Sclerosis (P4.161)

OBJECTIVE:To investigate the radiological value of a prototype implementation of T 1 -weighted MP2RAGE and MPRAGE as well as T 2 -weighted FLAIR techniques on a 7T magnetic resonance imaging (MRI) platform. BACKGROUND: Ultra-high-field (UHF) MRI has become more intensively used by clinical researchers investigating neurological diseases such as multiple sclerosis (MS). However, the added clinical value of UHF MRI and the use of advanced sequences to improve patient management in MS remain to be determined. DESIGN/METHODS: Five MS patients were consented for this pilot study. Structural whole-brain imaging was done on a 7T research system (Siemens, Erlangen, Germany). In one patient, both an MP2RAGE sequence and an MPRAGE sequence were repeated after injection of gadolinium-based contrast agent (GBCA). RESULTS: T 1 -weighted M2PRAGE images at 7T provided the most homogenous contrast across the brain and displayed higher gray-to-white matter contrast (CNR MP2RAGE /CNR MPRAGE = 2.67 and CNR MP2RAGE /CNR FLAIR = 2.33) and improved visualization of the pons and cerebellum (poorly visible on MPRAGE and FLAIR). A qualitative assessment across the five subjects revealed the same lesion distribution on the three sets of images, but lesions were most conspicuous on MP2RAGE. This improved conspicuity was observed in all cardinal lesion locations: spinal cord, infratentorial, periventricular, and juxtacortical. These qualitative findings were further supported by quantitative measurements of lesion- to white-matter contrast. MP2RAGE showed the highest contrast for periventricular lesions (CNR MP2RAGE /CNR MPRAGE = 3.15 and CNR MP2RAGE /CNR FLAIR = 3.49), deep white-matter lesions (CNR MP2RAGE /CNR MPRAGE = 2.87 and CNR MP2RAGE /CNR FLAIR = 2.95), and leukocortical lesions (CNR MP2RAGE /CNR MPRAGE = 2.84 and CNR MP2RAGE /CNR FLAIR = 3.15). This superiority of MP2RAGE was maintained after injection of GBCA. In addition, MP2RAGE sequence provided quantitative T 1 maps in agreement with the literature. CONCLUSIONS: MP2RAGE is a suitable technique for future clinical applications at 7T to overcome UHF-related artifacts while providing improved lesion conspicuity. Disclosure: Dr. Sati has nothing to disclose. Dr. Dewey has nothing to disclose. Dr. Sethi has nothing to disclose. Dr. Patil has received personal compensation for activities with Siemens AG. Dr. Kober has received personal compensation for activities with Siemens AG as an employee. Dr. Krueger has received personal compensation for activities with Siemens AG as an employee Dr. Reich has received research support from Vertex Pharmaceuticals.