[Scanography: yesterday and today].
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Brain Diseases↗
Biomedical subjects
D Melanson
Publications and source records attributed to D Melanson.
[Nuclear magnetic resonance: scanography of tomorrow].
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Humans↗
Sequential computed tomography scans in acute cerebral infarct.
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Cerebral Infarction↗
A reappraisal of lumbar discography.
Five hundred patients with negative or inconclusive pantopaque myelograms were investigated by lumbar discography. Discography remains the ideal complementary examination to demonstrate normal or diseased disc morphology and its findings were confirmed during surgery in 97.8% of explored discs. Discography is also a valuable clinical test since the injection may reproduce the patient's symptoms. Its observations were determinant in the surgeon's decision to explore a disc or not: 97.3% of patients submitted to laminectomy had an abnormal discogram and 73% of these patients experienced reproduction of clinical symptoms during the procedure. Myelography is superior to discography to demonstrate sequestered fragments, pachymeningitis and spinal stenosis, but was nevertheless not helpful in 56% of the patients in whom these diagnoses were made in the operating room.
Adolescent↗
Oxidative phosphorylation in pea cotyledon submitochondrial particles.
Mitochondria and submitochondrial particles (SMP) from pea cotyledons were shown to catalyze oxidative phosphorylation as measured by (32)Pi uptake into phosphate esters. ATP synthesis was sensitive to the electron transport inhibitor KCN, the uncoupler carbonyl cyanide m-chlorophenylhydrazone, and the coupling factor inhibitor oligomycin. Experiments with the adenine nucleotide translocator inhibitor atractyloside indicated the SMP were inside-out. Mersalyl completely inhibited ATP synthesis by SMP, and a separate experiment indicated that mersalyl has a direct effect on the ATPase complex. The kinetics of ATP synthesis indicated a high affinity for phosphate (K(m) = 0.18 millimolar). ADP kinetics gave a biphasic curve with K(m) values of about 4.8 and 160 micromolar. O(2) uptake and ATP synthesis had a pH maximum of 7.6 while the ratio of micromoles phosphate esterified to microatoms O(2) taken up was highest at pH 7.2. Sodium chloride inhibited both ATP synthesis and O(2) uptake but stimulated the ATPase reaction. The SMP also catalyzed a slow ATP-phosphate exchange reaction.
Journal Article↗
Primary ectopic meningioma of the neck: MR features.
Although meningiomas represent 15% of the tumors of the CNS, primary ectopic meningioma is a very rare finding. Four mechanisms for the formation of ectopic meningioma have been suggested: (a) direct extension of an intracranial lesion; (b) distant metastasis from an intracranial meningioma; (c) origin from arachnoid cells within the sheaths of cranial nerves; and (d) origin from embryonic nests of arachnoid cells. The case we present underwent a complete neuroradiological screening, and, although the neuroradiological findings were nonspecific to provide a correct diagnosis, they were useful for assessment of the tumor extension and for surgical planning. Particularly, magnetic resonance gave a panoramic view of the tumor and suggested its extensive vascularization, which was confirmed later by angiography.
Adult↗
MRI of amygdala and hippocampus in temporal lobe epilepsy.
In this study we compared the results of qualitative visual analysis of MRI with volumetric studies of the amygdala (AM) and hippocampal formation (HF) in a group of 31 patients. Twenty-six patients with temporal lobe epilepsy (TLE) and six with non-TLE had MRI studies using a 1.5 T Gyroscan following a specific protocol for scan acquisition. The MR images were interpreted by two blinded radiologists and by a third if discrepancy arose. Volumetric studies were carried out by one or two raters. The volumetric measurements of AM and HF were accurate in lateralizing the epileptogenic area in patients with TLE, concordant with the EEG in 92%; there was no false lateralization. In those patients who underwent surgery, there was a correlation between the degree of mesial temporal sclerosis demonstrated by histopathology, the amount of volume reduction, and the asymmetry. In patients with non-TLE, there was no volume asymmetry of AM or HF. The MR qualitative assessment yielded positive lateralization in patients with TLE in 56%, conflicting lateralization in 20%, and lateralization contralateral to the focus in 12%. A hyperintense signal in mesial structures was found ipsilateral to the focus in 40% and contralateral in 12% of patients with TLE. Volumetric study improves the diagnostic yield of MRI evaluation in patients with TLE not related to gross structural lesions. The interrater variability is low and the data are accurate and reproducible. Because they are quantitative, volumetric studies permit better comparison of results in different subgroups of patients with TLE.
Adolescent↗
Leptomeningeal gliomatosis: MR findings.
We report a case of primary diffuse leptomeningeal gliomatosis documented by MR. The radiological findings guided the surgical biopsy toward the area involved. Pathological examination confirmed the diagnosis. The patient could consequently benefit from treatment, i.e., radiation therapy, which was followed by clinical relief.
Adolescent↗
Prolonged focal cerebral edema associated with partial status epilepticus.
Following several days of partial status epilepticus, three patients developed striking focal cerebral edema as demonstrated by computed axial tomography (CT) scan. An angiogram done in one patient showed a capillary blush and early cortical draining veins in the corresponding area. All patients developed severe focal neurological deficit which resolved as the edema improved, and this was demonstrated on serial CT scans (at 6 months, 1 month, and 2 months, respectively). In the first patient, an underlying tumor, and in the second and third, vascular occlusions, were suspected because we were not aware that edema due to status epilepticus could produce changes of such intensity and duration. The neurological disability after the partial status was long-lasting but reversed completely in our patients. Maximal radiological changes occurred in the area of maximal epileptic discharge. Minimal atrophic changes persisted in two of the three patients. The clinical, CT scan, and angiographic findings suggest that partial status epilepticus can be associated with abnormal vascular permeability leading to prolonged focal cerebral edema. Similar pathophysiology of lesser intensity may be responsible for shorter postictal neurological deficits. Awareness of this clinical and radiological entity should avoid misdiagnosis of cerebral tumor or infarction.
Adolescent↗
Sequential computerized tomographic appearance of strokes.
Eighteen consecutive patients satisfying predefined clinical criteria for embolic strokes were prospectively studied by sequential computerized tomography (CT). Their findings were compared to CT scans obtained from patients presumed to have suffered thrombotic strokes. Our data reveal that the CT appearance of hemorrhagic infarction is likely to occur twice as frequently (22%) in CT scans of strokes presumed embolic than in those presumed thrombotic, where hemorrhagic infarction appeared at some time in 10% of the patients. No patient deteriorated with anticoagulation regardless of the CT appearance. In patients showing hemorrhagic infarction before anticoagulants, follow-up scans obtained after the administration of anticoagulants revealed resolution of the hemorrhagic aspect.
Adult↗
Cerebral amyloid angiopathy presenting as nonhemorrhagic diffuse encephalopathy: neuropathologic and neuroradiologic manifestations in one case.
A case of cerebral amyloid angiopathy is presented with MR imaging findings of high intense signal on T2-weighted sequences at the level of the white and gray matter of both hemispheres in the absence of neuroradiologic signs of cerebral hemorrhage. The biopsy specimen revealed deposition of amyloid in the walls of the intracranial arterial branches and focal ischemic changes and gliosis in the gray and white matter. We consider this presentation to be very unusual in patients affected by cerebral amyloid angiopathy.
Adult↗
Glioependymal cysts: CT and MR findings.
Four patients with intracranial glioependymal cysts were evaluated in our institution in the last 7 years. All underwent surgical drainage and biopsy of the cyst wall. Cranial CT revealed a uniformly hypodense lesion with no contrast enhancement in all cases. Magnetic resonance imaging studies revealed a well defined cyst that was isointense to CSF on T1-weighted images and iso- or mildly hyperintense to CSF on proton density and T2-weighted images. In one case, a fluid-fluid level was demonstrated within the cavity, indicating the presence of fluid with a high protein content. A diagnosis of glioependymal cysts can be suggested based on CSF-like intensity patterns on T1-weighted images and iso- or mild hyperintensity on T2-weighted images.
Adult↗
Bilateral thalamic glioma: review of eight cases with personality change and mental deterioration.
PURPOSE: To describe the clinical, radiographic, and neuropathologic features of bilateral thalamic glioma. METHODS: We searched our hospital records (1963 to present) to identify patients diagnosed as having the disease. RESULTS: Our search revealed eight patients, ranging in age from 8-63 years, with bithalamic tumor diagnosed by angiography, CT, and/or MR. All patients displayed personality changes and/or mental deterioration, including memory loss, inattention, confusion, hallucination, hyperphagia, or slow mentation. Unilateral motor weakness was also noted in six cases. The tumor always involved the medial aspect of the left and right thalami, but was often more extensive. The pathology was determined to be grades I-IV astrocytoma, confirmed by stereotactic biopsy or autopsy in six. Mild to moderate hydrocephaly occurred in some cases and was considered to be a contributing factor to mental deterioration. No correlation was found between age and type of tumor. CONCLUSIONS: Bilateral glioma of the dorsomedial and intralaminar nuclei of the thalamus can be a primary cause of dementia that has not been well-recognized in the past. CT and particularly MR should be considered for patients presenting with personality change or dementia, because of the possible presence of this unusual but devastating disease.
Adolescent↗
Intracerebral gangliogliomas in patients with partial complex seizures: CT and MR imaging findings.
The clinical and radiologic findings in 19 patients with partial complex seizures and surgically proved intracerebral gangliogliomas were reviewed to characterize the radiologic features of these lesions. The CT and MR findings were not specific. On CT the gangliogliomas can be hypodense with no enhancement and they often have calcifications. On MR these tumors have a wide variety of signals. In five of our cases the tumor had a high-intensity signal with a cystlike component on proton density- and T2-weighted images. In five cases the lesion had an inhomogeneously intense signal on proton density-weighted images and high signal intensity on T2-weighted images. The tumor had high-intensity signal on both proton density- and T2-weighted images in four patients. Finally, in two cases the MR findings were normal. We recommend MR as the examination of choice for patients with partial complex seizures because it allows an artifact-free evaluation of the temporal region. However, CT should also be performed in order to recognize calcifications that may be missed on the MR examination.
Adolescent↗
Spinal angiolipomas: CT and MR aspects.
Spinal angiolipomas are rare benign tumors containing vascular and mature adipose elements. In greater than 90% of the cases they are located in the epidural space. The clinical symptomatology is nonspecific, but CT and particularly MR studies allow for a precise diagnosis. Computed tomography (four cases in the literature plus one explored in our department) showed a hypodense lesion in 80% of the cases. In one case the angiolipoma was isodense to the cord. Magnetic resonance (three cases in the literature plus two explored in our department) showed a more or less homogeneous mass with a signal in T1- and T2-weighted images close to that of the subcutaneous fat. The infusion of gadolinium (one case in the literature plus one of ours) is helpful as an indicator to the degree of vascularization of the angiolipoma.
Adult↗
MR imaging of epidermoid cysts.
Nine patients with epidermoid cysts, five of them pathologically proved, were evaluated with MR imaging. Six patients also had CT. The cases were reviewed to evaluate the MR appearance of epidermoid cysts and to compare the MR findings with those of CT. The epidermoid cysts demonstrated low-signal intensity on T1-weighted MR images and hyperintensity on T2-weighted images. In five cases the cysts appeared heterogeneously iso- to hyperintense on the intermediate echo, and were surrounded by a thin rim of high signal intensity, which we believe was caused by encased CSF. The CT scans showed the cysts as low-density, well-demarcated lesions that do not enhance after infusion with contrast material. We conclude that MR is superior to CT in the evaluation of epidermoid cysts and is particularly useful in surgical planning.
Adolescent↗
Anderson-Fabry disease: a case report with MR, CT, and cerebral angiography.
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Adult↗
Computed tomography of intracranial gangliogliomas.
Thirteen patients with pathologically proven gangliogliomas were studied radiographically. The computed tomographic (CT) features of these 13 lesions and the other 35 cases in the literature were analyzed. Although the CT appearance of gangliogliomas was varied, certain characteristics were noted. The most common location was in the cerebral hemispheres, most often the temporal lobe. At least part of the tumor was low density in 71% of the unenhanced CT examinations. There were focal calcifications in 35% and enhancement with contrast material in 50%.
Adolescent↗