Matthew Gregory Young DO, Presenter: Nothing to Disclose

Benjamin Adam Cohen MD, Abstract Co-Author: Nothing to Disclose

Christopher Glielmi PhD, Abstract Co-Author: Employee, Siemens AG

Vito Ruggiero, Abstract Co-Author: Nothing to Disclose

Mary Bruno RT, Abstract Co-Author: Nothing to Disclose

Himanshu Bhat, Abstract Co-Author: Employee, Siemens AG

Timothy Michael Shepherd MD, PhD, Abstract Co-Author: Nothing to Disclose

Multiband pulse sequence design is a recent research tool that facilitates simultaneous acquisition of multiple slices for diffusion or functional MRI. This can be used to accelerate MRI acquisitions for user-specified temporal, spatial or angular resolutions. We investigated the potential of this new multiband technology to accelerate routine diffusion MRI acquisitions in clinical patients. 

We obtained both routine and multiband 2-slice acceleration of a diffusion MRI sequence for 25 consecutive clinical outpatients (mean age 46 ± 21 yrs, 18 female). This typical cohort for our practice included patients with normal MRI except for white matter changes (7), multiple sclerosis (4), vascular malformations (2) and postsurgical follow-up brain tumors (7). The routine diffusion MRI sequence at 3-T with a 20 channel head & neck coil had 1.5-mm in-plane resolution and 5-mm slices (3 directions, 2 averages, b-values = 500 & 1000 s/mm2). Diffusion trace images for both techniques were randomized and anonymized, then compared side-by-side by 3 board-certified neuroradiologists for diagnostic quality, artifacts and signal-to-noise ratios (SNR). Quantitation of the apparent diffusion coefficient (ADC) for frontal horn CSF and the centrum semiovale also were compared.

In all 25 patients, the multiband diffusion MRI acquisition was successfully acquired, free of major artifacts and considered of equivalent diagnostic quality. Multiband 2-slice acceleration reduced diffusion MRI sequence relaxation time to 3.9 sec and reduced overall scan time by 38% to 81 sec. The gray-white contrast in trace diffusion images was unchanged suggesting increased T1-weighting was negligible. There was a subtle mild decrease in SNR for the posterior fossa that did not compromise perceived image quality. There was no significant difference for the ADC of the centrum semiovale (unpaired t-test, P > 0.05) and CSF ADC differed by only 2%.

Multiband sequences can be used to reduce routine diffusion MRI acquisitions in clinical patients by 38% without compromising image quality.  This novel research technology should greatly facilitate translation of multiple diffusion-based brain mapping techniques to real patients.

Multiband sequence acceleration may accelerate clinical MRI acquisitions and finally allow translation of time-intensive diffusion-based brain mapping techniques to real clinical patients.

Young, M, Cohen, B, Glielmi, C, Ruggiero, V, Bruno, M, Bhat, H, Shepherd, T, Multiband Sequence Reduces Scan Times for Diffusion MRI and Tractography in Clinical Patients.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14012254.html