Reversal of restricted diffusion in cerebral venous thrombosis: case report

We report a patient with extensive cerebral venous thrombosis who showed complete reversal of restricted diffusion on MRI, accompanied by excellent clinical recovery. The implications of these findings in relation to interpretation of diffusion changes in cerebral venous thrombosis are discussed, and differences with arterial stroke are highlighted.     

Variance of the position of the cerebellar tonsils with age: preliminary report.

The position of the cerebellar tonsils relative to the foramen magnum was measured with sagittal magnetic resonance (MR) images in 221 patients aged 5 months to 89 years who were considered not to have disorders that would affect tonsillar position. All patients were grouped according to age. All measurements of the tonsils were obtained directly from the video console. Statistically significant (P less than .05) differences in tonsillar position were found between the 1st and 9th decades (P less than .001) and the 3rd and 9th decades (P less than .003) of life. An obvious trend existed: tonsillar ascent with increasing age. Therefore, the authors believe that a single reference standard that indicates the normal distance of the cerebellar tonsils from the foramen magnum is inappropriate unless age is considered. They suggest that the following distances below the foramen magnum (more than 2 standard deviations out of the normal range) be used as criteria for ectopia of the cerebellar tonsils: 1st decade of life, 6 mm; 2nd and 3rd decades, 5 mm; 4th to 8th decades, 4 mm; and 9th decade, 3 mm.     

Phase-contrast imaging of the parotid region

Standard T1- and T2-weighted spin-echo acquisitions were compared with T1- and T2-weighted phase-contrast techniques in a series of 10 consecutive patients with parotid masses to assess the role of phase-contrast methods in the evaluation of lesions in the parotid fossa. Greater tissue-lesion contrast was obtained with phase-contrast methods in nine of 10 cases, allowing improved lesion visualization; however, an increase in lesion detectability was not observed in this series. Standard MR imaging methods are sufficient for imaging the parotid region in most cases, but can be quite time-consuming. Recommended screening of the parotid fossa that optimizes tissue-lesion contrast, lesion detectability, and imaging time is performed by combining a standard T1-weighted acquisition with a T1- or T2-weighted phase-contrast acquisition. Selection of a T1- or T2-weighted phase-contrast acquisition is determined by the T1 characteristics of the lesion.     

Somatosensory cortical atrophy after spinal cord injury: a voxel-based morphometry study

The authors used voxel-based morphometry to compare sensorimotor cortical gray and white matter volume on structural MR images of a group of 17 individuals with cervical spinal cord injury (SCI) and a group of 17 healthy subjects. SCI subjects had reduced gray matter volume bilaterally in primary somatosensory cortex (p < 0.001). These findings suggest that the somatosensory cortex of the human brain atrophies after SCI.