Activation of the sensorimotor cortex at 1.0 T: comparison of echo- planar and gradient-echo imaging

• Published in: American journal of neuroradiology : AJNR Vol. 19; no. 6; pp. 1099 - 1104
• Main Authors: van der Kallen, BF, van Erning, LJ, van Zuijlen, MW, Merx, H, Thijssen, HO
• Format: Journal Article
• Language: English
• Published: Oak Brook, IL Am Soc Neuroradiology 01.06.1998; American Society of Neuroradiology
• Subjects: Adult; Arousal - physiology; Biological and medical sciences; Brain Mapping - instrumentation; Comparative Study; Echo-Planar Imaging - instrumentation; Female; Humans; Image Processing, Computer-Assisted - instrumentation; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Imaging - instrumentation; Male; Medical sciences; Motor Cortex - physiology; Motor Skills - physiology; Nervous system; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Reference Values; Sensitivity and Specificity; Somatosensory Cortex - physiology; Human; Cartography; Central nervous system; Sequence; Nuclear magnetic resonance imaging; Gradient echo; Sensorimotor cortex; Medical imagery; Adult; Technique; Motricity; Comparative study; Brain (vertebrata)
• ISSN: 0195-6108; 1936-959X

The increasing demand for the clinical application of functional MR imaging raises the question of whether this technique can be routinely performed on 1.0-T MR scanners. To this end, we assessed the feasibility of functional MR imaging at 1.0 T. Healthy volunteers were scanned during the performance of a motor task. Functional data were acquired with echo-planar imaging (EPI) and with gradient-echo (GRE) and dual-echo GRE sequences. The signal intensity variations of the EPI and GRE sequences were compared, and the influence of inflow and blood oxygen level-dependent (BOLD) effects on the signal variations was assessed with the dual-echo GRE sequences. In 11 of the 12 subjects we found activation in the primary motor cortex with both the GRE and EPI sequences. Active voxels had a significantly higher mean percentage of signal changes with the EPI sequence than with the GRE sequence (EPI: 1% to 6.1%, mean 2.4%; GRE: 1% to 4.5%, mean 1.9%). The EPI sequence was less sensitive to motion artifacts and enabled imaging of a larger brain volume in a shorter time. With a dual-echo sequence we found an increasing contribution of inflow effect with an increasing percentage of signal changes. Functional MR imaging of the sensorimotor cortex can be routinely performed at 1.0 T.