Functional MRI in the Recovery of Hand Movement after Subcortical Stroke

OBJECTIVE: To investigate cortical reorganization of the brain during voluntary activities of the hand in patients with subcortical cerebral infarction. METHOD: Twelve patients with first-ever subcortical brain lesion causing hemiparesis had been evaluated with functional MRI. Bilateral hand clenching was done to test voluntary hand activities. Recovery period ranged from 2 to 36 months. RESULTS: During the unaffected hand movement, activation of contralateral primary sensorimotor cortex (SMC) were recorded in all cases and supplmentary motor area (SMA) in 1 case. The affected hand movement showed activation of the cotralateral SMC in all cases, ipsilateral SMC in 4 cases, SMA in 4 cases and contralateral prefrontal area in 2 cases. As for the contralateral SMC, affected hand movement showed more increased activation than the unaffected. For the bilateral SMC activation during movement of the affected hand, contralateral SMC activation was greater than the ipsilateral. CONCLUSION: Ipsilateral activation of the SMC, SMA, prefrontal area and increased activation of the contralateral SMC during affected hand movement suggest that these may play an important role in the reorganization of sensory and motor system in stroke patients with subcortical lesion. Functional MRI studies of patients who recovered from subcortical stroke provide evidence for several process that may be related to restoration of neurologic function.

Usefulness of Enteral Contrast Media in MR Evaluation of Pelvic Mass

PURPOSE: To assess the value of enteral contrast media for the evaluation of pelvic masses by MR imaging. MATERIALS AND METHODS: Between April and July 1998, 16 women with pelvic masses were examined by MRI. The origin of the lesion was the ovary in twelve cases, the uterus in three, and the sigmoid in one. Using a 1.5T scanner(Magnetom Vision, Siemens), T1-weighted axial spin echo(SE), T2-weighted turbo spin echo(TSE), two-dimensional fast low-angle shot(FLASH 2D), and half-Fourier TSE(HASTE) images were obtained in all patients after the administration of Magnevist Enteral (Shering, Berlin, Germany). In each MR imaging sequence, distinction between the lesion and adjacent bowel (1, not distinguished; 2, partly distinguished; 3, clearly distinguished), artifact (0, absent; 1, mild; 2, severe), image quality (1, poor; 2, fair; 3, good), were compared before and after the use of enteral contrast media. Changes in MRI impression after the use of enteral contrast media were also evaluated. Two radiologists reached a consensus after reviewing the images. Statistical significance was determined by Wilcoxon's signed ranked test. RESULTS: For distinguishing lesions, SE T1WI and FLASH 2D with enteral contrast media were significantly superior to SE T1WI without enteral contrast media (p<0.05). With regard to image quality, FLASH 2D and HASTE, both with enteral contrast media, were significantly superior to SE T1WI and TSE T2WI, respectively, both without enteral contrast media (p<0.05). Artefacts were more frequently found after the application of enteral contrast media in conventional sequences but were not present in breathhold sequences. In two patients, MRI impression changed after the appilication of enteral contrast media. CONCLUSION: In a limited number of cases, enteral contrast media improved lesion detection, image quality and diagnostic accuracy when breathhold fast MR imaging was applied.