Clinical applications of functional MRI at 1.0 T: motor and language studies in healthy subjects and patients

In this article we describe clinical applications of functional MRI (fMRI) at 1.0 T. All experiments were performed on a commercially available 1.0-T system (Magnetom Impact Expert, Siemens AG, Erlangen, Germany) using a bloo d oxygen level-dependent (BOLD)-sensitive multi-slice EPI technique (TE 66 ms, 4 mm slice thickness, 210 mm field of view, 64 x 64 acquisition matrix) . Different paradigms for localization of the motor cortex and for language lateralization were tested in healthy subjects and patients. Methodologica l considerations concerning the development of the paradigms are also descr ibed. In all healthy subjects, motor activation elicited BOLD signal change s in the sensorimotor cortex, permitting identification of primary motor an d sensory cortical areas. Furthermore, focal activation of different cortic al areas by a language task was possible in 6 of 10 subjects. Nineteen moto r studies were performed in 18 patients with supratentorial lesions, in mos t cases prior to neurosurgical procedures. In 14 studies, fMRI results demo nstrated the localization of the motor hand areas relative to the lesion. T he results proved valuable for preoperative planning and contributed to the rapeutical decisions. We conclude that functional MRI for clinically releva nt applications, such as localization of motor and language function is fea sible even at a field strength of 1.0 T without dedicated equipment.