Present theory holds that pulsatile pressure of cerebrospinal fluid (CSF) is driven by the force of expansion of the choroid plexus. Alternate theories postulating that a possible movement of the brain is involved in pumping CSF have not, to the authors' knowledge, been substantiated heretofore. In this study, in vivo, quantitative magnetic resonance (MR) imaging methods were developed to show reproducible magnitudes and directions of CSF flow. Measurements were obtained with a new MR velocity imaging technique at high resolution (0.4 mm/sec), requiring 64 cardiac cycles per image. Twenty-five healthy volunteers and five patients were studied. Observations of pulsatile brain motion, ejection of CSF out of the cerebral ventricles, and simultaneous reversal of CSF flow direction in the basal cisterns toward the spinal canal, taken together, suggest that a vascular-driven movement of the entire brain may be directly pumping the CSF circulation. The authors describe what they believe to be the first observations and measurements of human brain motion, which occurs in extensive internal regions (particularly the diencephalon and brain stem) and is synchronous with cardiac systole.

Conjugation can be used to synthesize half of the data acquired during a conventional two-dimensional Fourier transform imaging procedure, thus reducing imaging time by nearly half. The images acquired by this process have the same object contrast and spatial resolution as conventional images do, but with a 40% reduction in the signal-to-noise ratio (S/N). Conjugation can be used to advantage in magnetic resonance imaging units in which S/N levels are higher than needed to permit imaging with a single acquisition of each projection.

To assess the capability of magnetic resonance (MR) imaging to enable differentiation of adenomyosis from leiomyoma, a prospective study was performed in 21 premenopausal patients with a strong clinical suggestion of adenomyosis. Histologic findings from hysterectomy (19 patients) and biopsy specimens (two patients) showed that eight patients had adenomyosis (three focal, five diffuse) and 12 had leiomyomas (five of the 12 also had microscopic foci of adenomyosis); one patient had a normal uterus. All eight cases of adenomyosis were correctly diagnosed from MR images. On T2-weighted MR images, diffuse adenomyosis appeared as a thickening of the junctional zone, whereas focal adenomyosis appeared as a low-signal-intensity mass poorly marginated from the adjacent myometrium. Ten of the 12 leiomyomas were correctly diagnosed from MR images. In the other two cases of leiomyoma, differentiation between focal adenomyosis and leiomyoma was not possible. Microscopic foci of adenomyosis were not demonstrated with MR imaging.

Fifty-seven patients with hemorrhagic intracranial lesions were examined with magnetic resonance (MR) imaging at 1.5 T with use of both spin-echo (SE) and gradient-echo-acquisition (GEA) techniques to assess the clinical applications and limitations of GEA in evaluation of intracranial hemorrhage at high field strength. All GEA images were obtained with a long echo time and short flip angle to emphasize T2*-based contrast. In 30 of 61 cases, GEA images demonstrated more hemorrhagic lesions than SE images. In 14 of 61 cases, GEA images failed to depict the lesion or obscured the specific diagnosis (as depicted by SE MR imaging). The authors believe that GEA imaging in its current form has a limited but definite adjunctive role in the evaluation of intracranial hemorrhage at high field strength.

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