Diffuse leptomeningeal gliomatosis associated with multifocal CNS infarcts.

BACKGROUND: Widespread dissemination of astrocytoma throughout the cerebrospinal fluid is unusual, especially as the initial presentation in a patient, and association with cerebral infarcts is rare. CASE DESCRIPTION A 47-year-old man subacutely developed progressive headache and backache, vomiting, altered consciousness, and numbness in both arms. Brain computerized axial tomography showed calcification in the fourth ventricle and magnetic resonance imaging demonstrated diffuse meningeal enhancement, a lesion in the canal of Magendie, and T2-weighted hyperintense lesions in several locations. Angiography showed vasospasm/vasculopathy involving multiple cerebral vessels. Biopsy of the fourth ventricular mass revealed a subependymoma with an overlying leptomeningeal anaplastic astrocytoma with numerous Rosenthal fibers. The patient was treated with three doses of intrathecal methotrexate via lumbar puncture but suddenly became unresponsive and died 6 days later, 8 weeks after initial symptoms. Autopsy demonstrated the subependymoma and a widespread leptomeningeal anaplastic astrocytoma, which showed no clear-cut origin from the subependymoma, but microscopically infiltrated the left medial temporal lobe. Multiple subacute and acute infarcts of the brain, brain stem, and upper spinal cord were seen only in areas with leptomeningeal tumor. CONCLUSION Glioma cells surrounding and focally permeating central nervous system vessels without lumenal occlusion can lead to vasospasm and widespread infarcts.

Transdural spinal cord herniation: imaging and clinical spectra.

PURPOSE: Transdural herniation of the spinal cord is a rarely reported clinical entity, and many of the existing reports were published before the advent of MR imaging. We describe five current cases and compare them with findings in 25 cases reported in the literature to delineate the clinical and imaging spectra of transdural spinal cord herniation. METHODS: MR imaging, CT myelography, and conventional myelography were performed in five patients with transdural herniation of the spinal cord. These studies, along with clinical findings, are described. Intraoperative photographs are included for one case. The salient features of both the current and previously reported cases are summarized in tabular form. RESULTS: In three cases, transdural spinal cord herniation occurred posttraumatically, in one case the cause was iatrogenic and in the others the herniation occurred spontaneously. Imaging features not previously reported include dorsally directed herniations at thoracolumbar levels (two patients), apparent (lacking surgical confirmation) syringomeyelia (one case), a vertebral body nuclear trail sign (one case), and intramedullary hyperintensities on MR images (two cases). Clinical features not previously reported include unilateral pyramidal-sensory deficits (one case) and isolated unilateral pyramidal signs (one case). Clinical findings similar to previous reports include progressive paraparesis (two cases) and progressive Brown-Séquard syndrome (one case). CONCLUSION: Our five cases illustrate certain clinical and imaging findings not previously reported, and, together with the established features of the 25 cases in the literature, delineate the spectra of transdural spinal cord herniation.

White matter disease induced by high-dose chemotherapy: longitudinal study with MR imaging and proton spectroscopy.

PURPOSE: The purpose of this study was to determine the time course for development of white matter changes induced by high-dose chemotherapy. METHODS: Eight patients with advanced breast cancer were entered into a prospective, longitudinal trial that included examination by MR imaging and proton MR spectroscopy before chemotherapy and through 12 months after treatment with carmustine, cyclophosphamide, and cisplatin, combined with autologous hematopoietic progenitor cell support (AHPCS). RESULTS: Six patients completed induction chemotherapy, at which time all MR imaging studies appeared normal. At 3 months after the conclusion of high-dose chemotherapy and beyond, three of the four patients remaining in the study showed an increasing volume of white matter changes, which appeared to stabilize during the period from 6 months to 1 year. Maximal volumes of abnormal white matter ranged from 73 to 166 cm3. MR spectroscopy showed little or no change in metabolic ratios through the period of observation, although there was a suggestion of small transient treatment-related decreases in the ratio of N-acetyl aspartate (NAA) to creatine. CONCLUSION: White matter changes are common sequelae of treatment with high-dose chemotherapy combined with AHPCS, occurring early in the period following high-dose chemotherapy, with a rapid and progressive accumulation to about 6 months, but not accompanied by persistent neurologic symptoms. The MR spectroscopic analyses suggest a minimal disturbance of the neuronal marker NAA, a finding that may in part explain the good neurologic outcome.

Treatment of recurrent glioma with intracavitary alloreactive cytotoxic T lymphocytes and interleukin-2.

For a single-dose toxicity assessment, five patients with recurrent malignant glioma (ages 29-46 years) were treated with intracavitary alloreactive cytotoxic T lymphocytes (CTL) and interleukin-2 (IL-2). The trial tested the hypothesis that alloreactive CTL, sensitized to the major histocompatibility complex (MHC) proteins of the patient, offer selective, targeted killing of glioma cells that express MHC. Patient lymphocytes, which also express MHC, were irradiated and placed into CellMax artificial capillary systems with lymphocytes from MHC-disparate donors and CTL developed over a 2- to 3-week period with a low concentration of IL-2. The CTL largely expressed CD3 and CD11a/CD8 markers and lysed targets displaying patient MHC. CTL were implanted into the tumor bed at surgery and a catheter was used for subsequent infusions. Patients received one to five treatment cycles every other month; one cycle generally consisted of two or three CTL infusates administered within a 1- to 2-week period. Different unrelated donors were used for each cycle. Treatment was well tolerated; transient toxicity at grades 1-3 was recorded by NCI Common Toxicity Scale criteria. Two glioblastoma patients have died; one from tumor recurrence locally and the other from recurrence at a site distant from the treatment. Two of the five patients completed five cycles; one anaplastic oligodendroglioma patient shows no evidence of tumor 30 months from the start of immune therapy and an anaplastic astrocytoma patient shows stable disease 28 months after initiation of therapy. One anaplastic oligodendroglioma patient, who dropped the protocol during her second treatment cycle, has no evidence of tumor 28 months after recurrence.

MR enhancing brain lesions in methanol intoxication.

Methanol intoxication can cause necrosis of the putamen and subcortical white matter that is evident on neuroimaging. We report a 47-year-old man with significant methanol intoxication who had enhancing lesions in the caudate nuclei, putamina, hypothalamus, and subcortical white matter by MRI. This case demonstrates that contrast enhancement of brain lesions can be observed after methanol poisoning.

The imaging of epilepsy.

Based on the experience of a university neurological epilepsy center, the neurological classification and the gradation of neurological evaluation of patients with epilepsy are described. Into this the nature and the significance of the imaging of the brain are interwoven. The object, illustrated by several illustrative patients, is to stress the importance of the MRI and to note that based on the MRI findings and the clinical findings, the battery of sophisticated electroencephalographic evaluation is determined. Epilepsy is an area where imaging and all aspects of the clinical neurological evaluation integrate very well and in which correlation is most important.

MR and proton spectroscopy of white matter disease induced by high-dose chemotherapy with bone marrow transplant in advanced breast carcinoma.

PURPOSE: To determine whether the MR-detectable white matter changes associated with high-dose chemotherapy and bone marrow transplant in patients with advanced breast carcinoma are accompanied by neurochemical disturbances detectable by proton MR spectroscopy. METHODS: MR studies were obtained in 13 patients, and single-voxel proton MR spectra were acquired in vivo in 12 of these 13 for comparison with 13 age- and sex-matched control subjects. RESULTS: Considerable white matter change determined with MR was found in 10 of 13 patients with volume white matter change ranging from 1 to 153 cm3 (mean, 49 cm3; SD, 50 cm3). Single-voxel spectra successfully acquired in 12 patients revealed no significant difference in patients compared with control subjects for the spectral ratios N-acetyl aspartate to creatine or N-acetyl aspartate to choline at either short or long echo times (30 and 136 milliseconds). CONCLUSION: Extensive, late-stage white matter change induced by high-dose chemotherapy is not accompanied by measurable disturbances in the putative neuronal marker N-acetyl aspartate, suggesting that chemotherapy-induced white matter disease is predominantly a water space and possibly an extraneuronal process rather than a primary neuronal (axonal) disease. The MR spectroscopic examination, accomplished at the time of the MR imaging examination, complements the MR imaging study by increasing the specificity of the MR-based clinical evaluation.

The pathologic, surgical, and MR spectrum of Rathke cleft cysts.

BACKGROUND: Rathke cleft cysts (RCC) uncommonly attain large enough size to cause symptoms or warrant neurosurgical intervention, leading to difficulty in recognizing their diverse presentations. METHODS: We retrospectively reviewed the clinical, intraoperative, pathologic, and magnetic resonance (MR) imaging findings of 16 cases seen at our institution since 1987. RESULTS: The most unusual clinical presentation was pituitary apoplexy, although CSF-like, cholesterol containing, or hemorrhagic cyst contents most often led to intraoperative misinterpretation. Microscopic features of squamous metaplasia, lymphocytic infiltrates, tubuloracemose glands, or coexistent adenomas demonstrated the pathologic variations in these intrasellar and suprasellar cysts. The MR findings of an anteriorly displaced pituitary stalk, the presence of a posterior ledge, and T2 hypointensity were distinctive, when present. CONCLUSIONS: Rathke cleft cysts have varied clinical presentations and sometimes confusing intraoperative and pathologic appearances. We document a new pathognomonic MR finding in these cysts of a posterior ledge sign. Our surgical approach is to open and drain cyst contents, treat the residual cyst lining with instillation of absolute alcohol, and close the floor of the sella with a bone strut.

Subarachnoid neurocysticercosis with occlusion of the major intracranial arteries: case report.

Cysticercosis is the most common parasitic disease affecting the central nervous system. Stroke is a recognized complication of neurocysticercosis, occurring in 2 to 12% of cases, mostly in the form of small lacunar infarcts. We report a case of hemiparesis and aphasia in a 51-year-old Hispanic woman, which was secondary to complete occlusion of the left internal carotid and bilateral anterior cerebral arteries. Magnetic resonance imaging demonstrated the presence of enhancing subarachnoid material surrounding these occluded cerebral arteries, providing antemortem, noninvasive documentation of the inflammatory meningeal cysticercotic reaction that was presumably responsible for the occlusive arteritis causing the cerebral infarction. This represents the third reported case of internal carotid artery occlusion and the first reported case of anterior cerebral artery occlusion secondary to neurocysticercosis.

Quantitative contrast-enhanced MR imaging of the optic nerve.

During the acute stages of optic neuritis damage to the blood-optic nerve barrier can be detected using i.v. paramagnetic contrast-enhanced MR imaging. Quantification of the enhancement pattern of the optic nerve, intraorbital fat and muscle was determined in 15 normal subjects using 3 fat-suppression MR imaging methods: T1-weighted spin-echo and spoiled gradient-echo sequences preceded by a fat-frequency selective pulse (FATSAT+SE and FATSAT+SPGR, respectively) and a pulse sequence combining CHOPPER fat suppression with a fat-frequency selective preparation pulse (HYBRID). Pre- and postcontrast-enhanced studies were acquired for FATSAT+SE and FATSAT+SPGR. There was no significant enhancement of the optic nerve by either method (mean increase of 0.96% and 5.3%, respectively), while there was significant enhancement in muscle (mean 118.2% and 108.2%, respectively; p < 0.005) and fat (mean increase of 13% and 37%, respectively; p < 0.05). Postcontrast optic nerve/muscle signal intensity ratios (mean, SD) were 0.51 (0.07), 0.58 (0.05) and 0.75 (0.05) for FATSAT+SE, FATSAT+SPGR and HYBRID, respectively. These results suggest a practical methodology and range of values for normal signal intensity increases and ratios of tissue signal that can be used as objective measures of optic neuritis for natural history studies and treatment trials.

Trigeminal nerve and ganglion in the Meckel cave: appearance at CT and MR imaging.

PURPOSE: To demonstrate the anatomy of the Meckel cave, which is normally seen by means of dissection, with high-resolution computed tomography (CT) and magnetic resonance (MR) imaging. MATERIALS AND METHODS: Twenty cadaver specimens were scanned with 1-mm contiguous axial and coronal CT sections. Seven specimens were also scanned with 1-mm contiguous parasagittal sections and were dissected for correlation with CT images. Two volunteers also underwent high-resolution, fast spin-echo MR imaging. MR images were compared with the CT images and the results of dissection. RESULTS: Dissection and CT and MR imaging demonstrated that the trigeminal nerve within the Meckel cave consists of numerous small fibers and that the trigeminal ganglion consists of a small amount of solid tissue. CONCLUSION: In vivo, high-resolution, fast spin-echo imaging can demonstrate the anatomy of the trigeminal nerve in the Meckel cave because of improved spatial and contrast resolution.

White matter changes in patients with breast cancer treated with high-dose chemotherapy and autologous bone marrow support.

PURPOSE: To study MR changes in the white matter of the brain in patients with breast cancer treated with a widely used protocol of high-dose chemotherapy and autologous bone marrow support. METHODS: Thirteen patients with high-risk stage II or stage IV breast cancer treated with high-dose cyclophosphamide, cisplatin, carmustine, and bone marrow support underwent posttransplant MR examination of the brain. Serial posttransplant MR examinations were performed in 5 of the 13 patients and single MR examinations in 8. The severity of the white matter change was evaluated by two neuroradiologists and rated mild, moderate, or severe. RESULTS: In 9 of the 13 patients, central and peripheral cerebral white matter changes were observed. Four patients had severe changes, extending from the ependyma of the lateral ventricles to the gyri. An additional 4 patients had moderate white matter change at the last observation. One had mild change, and 4 had no white matter change. In all patients, there was sparing of inferior frontal, posterior inferior occipital, and anterior temporal lobes, and of the centrosylvian brain. CONCLUSIONS: White matter change occurred in patients treated with a high-dose chemotherapy and bone marrow support protocol. Most of the changes, and the more severe ones, occurred 5 or more months after the transplants. There was no apparent relationship between these changes and central nervous system function. Because of the increased longevity with this treatment, it is important to appreciate these white matter changes, recognizing however that their expression may be subclinical.

Radiation exposure and efficacy of exposure-reduction techniques during cardiac catheterization in children.

OBJECTIVE: The purpose of this study was to measure radiation exposure levels in children undergoing cardiac catheterization. This information was used to assess methods of reducing exposure and to characterize total exposures. SUBJECTS AND METHODS: The radiation exposure area product was determined for a total of 175 patients during three study intervals over 10 years. Examinations included biplane fluoroscopy and cineangiography for the diagnosis and treatment of congenital heart disease. RESULTS: The use of pulsed progressive fluoroscopy was found to reduce patients' fluoroscopic exposure rates by approximately 40% as compared with interlaced mode fluoroscopy. Combining exposures from the frontal and lateral projections, the median fluoroscopic time for diagnostic procedures was 21 min and the median time for cineangiography was 42 sec. Median total exposure area product was 2063 R-cm2 with cineangiography accounting for 44% of the total exposure. For an estimated X-ray beam entrance area of 50-100 cm2, the median total entrance exposure was in the range of 20-40 R. Fluoroscopy times for interventional procedures were found to be 1.5 to 2.5 times longer than for diagnostic procedures, with total exposures approximately three times higher. CONCLUSION: This study suggests that pulsed progressive fluoroscopy is an effective method of reducing radiation exposure in children undergoing cardiac catheterization.

Evaluation of resolution and sensitometric characteristics of an asymmetric screen-film imaging system.

The authors compared asymmetric and conventional screen-film systems for chest radiography. The new imaging system, with asymmetric construction of the screens and film, has image quality characteristics substantially different from those of available screen-film combinations. This asymmetric screen-film system consists of a thin (high-resolution) front screen and a high-contrast emulsion, a thick (lower-resolution) back screen and a low-contrast emulsion, and technology that reduces the crossover exposure and prevents light from the front screen from exposing the back emulsion and vice versa. With this system, density, contrast, and resolution can be increased in selected regions while maintaining density and contrast in the rest of the image. Also, the resolution of this system varies as a function of density. Preliminary image quality and sensitometric studies indicate the new system is superior for chest radiography because it provides better visualization of mediastinal, retrocardiac, and diaphragmatic regions while yielding better contrast and resolution in lung parenchyma.

A new asymmetric screen-film combination for conventional chest radiography: evaluation in 50 patients.

OBJECTIVE: A new asymmetric screen-film combination for conventional chest radiography was evaluated by four thoracic radiologists. MATERIALS AND METHODS: Fifty chest radiographs obtained with a new asymmetric screen-film combination were compared with radiographs obtained in the same patients during the same breath-hold with a conventional system. Patients referred from the oncology service were studied because of the increased prevalence of abnormal findings on chest radiographs in this population. The differences in the quality of the images were assessed by four chest radiologists who used a direct-comparison technique. Eleven anatomic shadows that are normal on chest radiographs were assessed. Fifty abnormal findings also were compared. RESULTS: The image quality of the new asymmetric screen-film combination was judged to be superior to that of the conventional system for normal anatomy and abnormal findings (p < or = .003). CONCLUSION: The new asymmetric film consistently showed more clinically useful detail in the mediastinum and in the lung projected over the diaphragm and heart. The radiation dose was about 30% less with the new screen-film system.

Intracranial aneurysms in autosomal dominant polycystic kidney disease.

BACKGROUND AND METHODS: Intracranial aneurysms are a feature of autosomal dominant polycystic kidney disease, but their prevalence is uncertain. We studied 92 subjects with autosomal dominant polycystic kidney disease who had no symptoms or signs of any neurologic disorder. To determine the prevalence of intracranial aneurysms, we performed high-resolution computed tomography (CT) in 60 subjects, four-vessel cerebral angiography in 21, and both procedures in 11. RESULTS: Four of the 88 subjects in whom the radiologic studies were successfully completed had intracranial aneurysms (4 percent; 95 percent confidence interval, 0.1 to 9 percent), as compared with the prevalence of 1 percent reported for an angiographic study of the general population. Three of the four subjects had multiple aneurysms. Seven subjects for whom the results of CT studies were suspicious underwent cerebral angiography: two had aneurysms, and five had normal vascular structures that accounted for the suspicious results of tomography. Four subjects who had normal CT imaging studies also had normal angiographic examinations. Eight of the 32 subjects who underwent angiography (25 percent) had transient complications, as compared with 22 of 220 control subjects (10 percent) who did not have polycystic kidney disease (P less than 0.05). We could not identify any risk factor in these subjects that was related to the occurrence of aneurysm. CONCLUSIONS: Asymptomatic intracranial aneurysms appear to be more frequent in people with polycystic kidney disease than in the general population, although our 95 percent confidence interval includes the possibility of no difference. Because cerebral angiography is associated with increased morbidity in people with polycystic kidney disease, we recommend high-resolution CT as a screening test.

Acceptance testing of radiologic systems: experience in testing 129 imaging systems at two major medical facilities.

The problems encountered in acceptance testing of newly installed imaging equipment at two major medical institutions over a 10-year period are presented. Acceptance tests were conducted in 129 newly installed imaging systems with conventional acceptance testing methods. A total of 1,132 problems were documented. Problems were classified as major or minor; there were 772 major problems and 360 minor problems. An average of six major and three minor problems were documented in each new equipment installation tested. In some instances, final payment was withheld for several months or more to ensure correction of the problems identified. This experience confirms the need of thorough acceptance testing of new imaging equipment before final payment is made to the vendor.

Beam-shaping device for long-film angiography.

Uniform radiologic exposure from the pelvis to the ankles is often difficult to achieve when long films (51-inch) are used for femoral angiography. A unique device developed to shape the x-ray beam accomplishes this task by using a movable shutter to obscure a portion of the x-ray beam. A microprocessor-controlled stepper motor modulates the amount of beam cutoff by regulating the movement of the shutter from the foot end of the film. The goal is to match exposure factors to the patient's body shape. This beam-shaping device has been evaluated and tested in examinations of 500 patients over the past year. A substantial improvement in image quality over that achieved with earlier systems of graduated screens and multiple wedge filters was seen in all cases. The system is esy to use, flexible, and especially valuable in imaging obese patients or those who have legs disproportionately smaller than their pelvis or abdomen.

Diffusely infiltrating brainstem gliomas: a report of the diagnostic difficulties in 2 cases.

Brainstem gliomas seem to present in 2 distinct ways. More commonly they are localized to 1 portion of the brainstem and present with signs that are both localizing and lateralizing. These are usually fairly easy to image neuroradiologically. The rarer diffusely infiltrating variety manifest a slowly building array of findings pointing to all levels and both sides of the brainstem. Our 2 cases exemplify the diffuse variety. They were clinically typical, and the CSF pressure and protein were elevated but the neuroimaging abnormalities were so subtle that they were originally overlooked. This subtlety of neuroradiologic abnormality resembles that found in gliomatosis cerebri.

Patterns of pulsatile pituitary glycoprotein secretion in central hypothyroidism and hypogonadism.

Five patients with central hypothyroidism and hypogonadism due to mass or infiltrative lesions of the pituitary and hypothalamus were studied to determine pulsatile pituitary glycoprotein secretion patterns. Blood samples were obtained every 15 min over 24 h, and TSH, LH and FSH were measured by immunoradiometric assays. Hormone pulses were located by cluster analysis, and pulse patterns were compared to those in normal subjects. Three patients had unmeasurable LH levels, while two had a normal number of low amplitude pulses. In contrast, all patients had normal FSH pulse frequency, and only one had low pulse amplitude. Three patients had normal 24-h TSH pulse frequency and amplitude, while two had slightly decreased pulse parameters. However, all failed to show normal nocturnal increases in TSH pulse amplitude. Thus, anatomical hypothalamic-pituitary lesions disrupt pulsatile glycoprotein secretion in a discordant fashion. LH is most severely affected, with abnormal pulse patterns similar to those in idiopathic central hypogonadism. FSH and TSH pulses are relatively preserved, but loss of the usual nocturnal increase in TSH pulse amplitude is sufficient to cause clinical hypothyroidism. Whether these defects reflect intrinsic pituitary disease or impaired hypothalamic releasing factor function remains to be determined.