Biology subjects

Alhulail, A. A.

Publications and source records attributed to Alhulail, A. A..

2 recordsLinked to original sources

bioRxiv2020

Fast in vivo 23Na imaging and T2* mapping using accelerated 2D-FID magnetic resonance spectroscopic imaging at 3 T: Proof of concept and reliability study

PurposeTo implement an accelerated MR-acquisition method allowing to map sodium T2* relaxation and absolute concentration within skeletal muscles at 3T. MethodsA fast-2D density-weighted concentric-ring-trajectory 23Na-MRSI technique was used to acquire 64 time-points of FID with a spectral bandwidth of 312.5 Hz from a 2.5 x 2.5 mm2 in-plane resolution within about 15 minutes. The fast relaxing 23Na signal was localized with a single-shot, inversion-recovery based, non-echo (SIRENE) OVS method. The sequence was verified using simulation and phantom studies before implementing it in human calf muscles. Within two same-day sessions, 2D-SIRENE-MRSI (UTE = 0.55 ms) and 3D-MRI (UTE = 0.3 ms) data were acquired. The T2* values were fitted voxel-by-voxel using a bi-exponential model for the 2D-MRSI data. Within-subject coefficients of variation were estimated for both acquisition methods. ResultsThe MRSI-FID data allowed for fast and slow T2* mapping of the calf muscles in vivo with minimal sensitivity reduction. The spatial-distributions of 23Na concentration for both in vivo MRSI and 3D-MRI acquisitions were significantly correlated (r = 0.7, P<0.001). The test-retest results rendered high reliability for both MRSI (CV = 5%) and 3D MRI (CV = 6%). The mean [Formula] in calf muscles was 0.7 {+/-} 0.1 (contribution fraction = 37%), while [Formula] was 13.2 {+/-} 0.2 ms (63%). The mean absolute muscle 23Na concentration calculated from the T2*-corrected data was 28.6 {+/-} 3.3 mM. ConclusionThe proposed MRSI technique is a reliable technique to map sodiums absolute concentration and T2* within a clinically acceptable scan time at 3T.

biophysics↗

bioRxiv2019

Musculoskeletal fat imaging and quantification by high-resolution metabolite cycling magnetic resonance spectroscopic imaging at 3 T: A fast method to generate separate distribution maps of lipid components

PurposeTo provide a rapid, non-invasive fat quantification technique capable of producing separate lipid component maps.\n\nMethodsThe calf muscles in 5 healthy adolescents (age 12-16 years; BMI = 20 {+/-} 3 Kg/m2) were scanned by two different fat fraction (FF) quantification methods. A high-resolution, density-weighted concentric ring trajectory (DW-CRT) metabolite cycling (MC) magnetic resonance spectroscopic imaging (MRSI) technique was implemented to collect data with 0.25 mL resolution within 3 minutes and 16 seconds. For comparative purposes, the standard Dixon technique was performed. The two techniques were compared using structural similarity (SSIM) analysis. Additionally, the difference in the distribution of each lipid over the adolescent calf muscles was assessed based on the MRSI data.\n\nResultsThe proposed MRSI technique provided individual FF maps for eight musculoskeletal lipids identified by LCModel analysis (L09, L11, L13, L15, L21, L23, L53, and L55) with mean SSIM indices of 0.19, 0.04, 0.03, 0.50, 0.45, 0.04, 0.07, and 0.12, respectively compared to that of Dixons FF map. Further analysis of voxels with zero SSIM demonstrated an increased sensitivity of FF lipid maps from data acquired using this MRSI technique over the standard Dixon technique. The trend of lipid spatial distribution over calf muscles was consistent with previously published findings in adults.\n\nConclusionThe advantages of this MRSI technique make it a useful tool when individual lipid FF maps are desired within a short scanning time.

biochemistry↗