Takahiko Tashiro

CT and MR imaging of cerebral tuberous sclerosis

Tuberous sclerosis is a heredofamilial neurocutaneous syndrome, or phakomatosis, with multisystem involvement including the brain, kidney, skin, retina, heart, lung, and bone. The brain is the most frequently affected organ in tuberous sclerosis. Brain lesions in tuberous sclerosis are of three kinds; cortical tubers, white matter abnormalities, and subependymal nodules. We review the computed tomography (CT) and magnetic resonance (MR) features of the brain lesions in patients with tuberous sclerosis. CT clearly demonstrates calcified subependymal nodules. MR imaging demonstrates more clearly cortical, and white matter lesions than CT, since MR imaging shows excellent image contrast between various normal structures and high sensitivity in detecting pathological states due to intrinsic differences in proton density and in particular, in proton relaxation times of tissues. Possible pathogenesis of this disorder is also discussed.

Lymphocytic adenohypophysitis: skull radiographs and MRI

Abstract We report the skull radiograph, CT and MRI findings in three patients with lymphocytic adenohypophysitis mimicking pituitary adenoma. All cases were associated with pregnancy. CT demonstrated a pituitary mass but did not differentiate lymphocytic adenohypophysitis from pituitary adenoma. The skull radiographs showed either a normal sella turcica or minimal abnormalities; they did not show ballooning or destruction. The MRI appearances were distinctive: relatively low signal on T1-weighted images; preservation of the bright posterior pituitary lobe despite the presence of a relatively large pituitary mass, less common in macroadenomas; marked contrast enhancement compared with pituitary macroadenomas; and dural enhancement adjacent to a pituitary mass.

Syringomyelia associated with adhesive spinal arachnoiditis: MRI

Abstract We reviewed the MRI of seven patients with syringomyelia associated with surgically proven adhesive spinal arachnoiditis to describe clinical and MRI findings in this condition. Using 0.5, 1.0 or 1.5 tesla units, we obtained sagittal T1- and T2-weighted spin-echo and axial T1-weighted images. Additional sagittal T2-weighted images were obtained without using motion-artefact suppression. Contrast medium was given intravenously to five patients. The syrinx cavities were thoracic in five cases, cervicothoracic in one, and extended from C4 to L1 in one. No Chiari malformation or craniovertebral junction anomaly was demonstrated. Meningeal thickening was seen on T2-weighted sagittal images only in one case. Cord deformity due to adhesion or displacement due to an associated arachnoid cyst was seen in all cases best demonstrated on axial images. Focal blurring of the syrinx wall on axial images was seen in six patients. Flow voids were seen in the syrinx fluid in all cases on T2-weighted images obtained without motion-artefact suppression. No abnormal contrast enhancement was demonstrated.

Intradural chordoma: case report and review of the literature

Chordomas are rare neoplasms arising from notochordal remnants found predominantly in the clivus and the sacrococcygeal regions. Most clivus chordomas show extradural extension and bone destruction. Such a tumour can rarely be intradural. This report is concerned with the radiological findings in prepontine intradural chordoma.

Rathke's cleft cyst associated with hypophysitis: MRI

Abstract We report a symptomatic Rathkes cleft cyst associated with hypophysitis in a 61-year-old woman. We demonstrate the MRI features and discuss the pathophysiology. To the best of our knowledge this is the first description of a Rathkes cleft cyst shrinking after high-dose steroid therapy.

Neurofibromatosis Type 1 and Type 2: review of the central nervous system and related structures

Although computed tomography (CT) provides a major imaging advance over conventional radiography and tomography in examining the whole body, the development of magnetic resonance (MR) imaging has proven to be an even greater breakthrough in diagnostic medical imaging. The anatomic detail demonstrated in a MR image is a representation of at least three physical properties of static-tissue: proton density, and T1 and T2 relaxation times. Intrinsic differences in proton density and, in particular, in proton relaxation times of tissues allow excellent image contrast between various normal structures and high sensitivity in detecting pathological states. This article discusses imaging features of neurofibromatosis, with particular emphasis on the potential of MR imaging.

Glucocorticoid treatment of brain tumor patients: changes of apparent diffusion coefficient values measured by MR diffusion imaging

Glucocorticoids (GCC) generally are administered to patients with brain tumors to relieve neurological symptoms by decreasing the water content in a peritumoral zone of edema. We hypothesized that diffusion imaging and apparent diffusion coefficient (ADC) values could detect subtle changes of water content in brain tumors and in peritumoral edema after GCC therapy. The study consisted of 13 patients with intra-axial brain tumor, and ADC was measured in the tumor, within peritumoral edema, and in normal white matter remote from the tumor before and after GCC therapy. ADC also was measured in normal white matter in four control patients with no intracranial disease who were treated with GCC for other indications. Conventional MR images showed no visually evident interval change in tumor size or the extent of peritumoral edema in any subject after GCC therapy, which nonetheless resulted in a decrease in mean ADC of 7.0% in tumors (P<0.05), 1.8% in peritumoral edema (P>0.05, not significant) and 5.8% in normal white matter (P<0.05). In patients with no intracranial disease, GCC therapy decreased mean ADC in white matter by 5.4% (P<0.05). ADC measurement can demonstrate subtle changes in the brain after GCC therapy that cannot be observed by conventional MR imaging. Measurement of ADC proved to be a sensitive means of assessing the effect of GCC therapy, even in the absence of visually discernible changes in conventional MR images.

Lateral sacral artery supply to an intramedullary arteriovenous fistula at the conus medullaris

SummaryIn this 25-year-old woman, severe low back pain, flaccid paraparesis, sensory disturbance of both legs and sphincter dysfunction resulted from an intramedullary conal arteriovenous malformation fed by an anterior spinal artery arising from the left sixth intercostal artery and by the left lateral sacral artery, a branch of the left internal iliac artery.

Subpial schwannoma of the cervical spinal cord mimicking an intramedullary tumor

We report a rare case of a subpial schwannoma of the cervical cord mimicking an intramedullary tumor in a 65-year-old woman. The magnetic resonance imaging findings are presented and discussed.