Biomedical subjects
Publications and source records attributed to B Azar-Kia.
This study investigated the effects of MRI on receptor-mediated activation of pineal gland indole biosynthesis. Exposure of rats to MRI reduced the effects of isoproterenol on pineal serotonin and N-acetylserotonin levels suggesting that strong magnetic fields and/or radio-frequency pulsing used in MRI inhibited beta-adrenergic activation of the gland. There was no effect of MRI on saline controls.
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Twenty patients with cerebral infarction were observed with serial computerized tomographic (CT) scans. Seventy percent of those infarctions showed a mass effect that had disappeared in all patients by the eighth week after the ictus. In 63%, there was enhancement after contrast infusion, with a definite temporal relationship to the day of onset of the neurological deficit. Twenty percent of the patients initially had normal CT scans that became abnormal weeks after the stroke. Radionuclide scans were positive in the patients who showed contrast enhancement, and the area of abnormal uptake correlated well with the area of enhancement. The timing of the performance of the CT scan in relation to the onset of neurological deficit is an important factor to consider when evaluating the stroke syndrome with CT.
A review of 5,000 computed tomographic (CT) brain scans revealed 76 patients with proved pathology involving the sellar and parasellar areas. The overall diagnostic accuracy of CT scanning was 93.4%, whereas the accuracy of isotope scanning, angiography, and pneumoencephalography was 55.4, 81 and 100% respectively. The criteria used in making the diagnosis with CT scanning are listed. The results indicate that CT scanning is the initial diagnostic procedure of choice, but that other modalities, particularly angiography, are still required for more accurate evaluation in the majority of cases.
The CT scan appearances of acute intracerebral hematoma are usually diagnostic, and can be differentiated from hemorrhagic tumor and infarction. Some prognostic evaluations can be made, depending on the site and size of the hemorrhage. Sequential studies indicate resolution of the density of the hematoma over a period of approximately six weeks. This however does not appear to correlate with pathological resolution, but does reflect the hemoglobin concentration in the hematoma. Angiography is indicated when an underlying AVM or aneurysm is suspected, whereas contrast infusion studies are not of great value in detecting these lesions.
Cysticercosis is a parasitic disease in which man serves as the intermediate host of Taenia solium, the pork tapeworm. The larvae have a predilection for the central nervous system and can cause a variety of neurologic and psychiatric symptoms. Areas of involvement are classified as intraventricular, parenchymal, arachnoidal, and mixed. The diagnosis is made primarily by roentgenographic and spinal fluid examinations. The authors reviewed 232 cases of cysticercosis involving the central nervous system. It was found that computed tomography is a useful tool in assessing this illness.
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A case of megadolichobasilar artery anomaly (MDBA) with expansion of the internal auditory meatus is presented. There was no associated hearing loss and it is postulated that IAM expansion without hearing loss may occur with this anomaly.
A brief history of the theories of pathogenesis of the origin of neuroepithelial cysts is presented. An origin more diffuse than the paraphysis seems most likely in our opinion, and we attempt to substantiate this theory with several of the cases from our series. One posterior third ventricular neuroepithelial cyst and one in the fourth ventricle are demonstrated roentgenographically. Also included in our series are a case showing suprasellar calcification on plain skull roentgenograms, not previously reported in neuroepithelial cysts, and a case with a cyst measuring 9 cm, the largest neuroepithelial cyst yet reported.
The dural branches from the cavernous portion of the internal carotid consists of the meningophypopseal trunk, the inferior cavernous, and the capsular arteries. These vessels have extensive anastomoses in and around the sellar area. These arteries are not usually demonstrated angiographically; therefore, when they are enlarged, a pathological lesion should be suspected. There are numerous lesions other than meningiomas associated with hypertrophy of these dural branches and the corresponding vessels involved depends on the anatomic location of the associated lesion.
The authors report a case of craniopharyngioma in a newborn infant. Marked hydrocephalus of the fetal head was recognized in the pelvimetric roentgenograms of the mother and massive suprasellar calcification was seen in the plain skull films.
The authors report and discuss the unusual clinical and roentgenographical features of three cases of angioblastic meningioma with extracranial metastases. The primary lesions occurred in the cervical canal, the parasagittal region, and the posterior fossa. Metastases were to lungs, liver, pancreas, and kidneys.
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A 58-year-old man with complex partial seizures had transient symmetrical MR enhancement in the anterior mesiotemporal cortex bilaterally, correlated with the sites of seizure focus on electroencephalography. Preinfused T1-weighted and T2-weighted sequences showed no abnormality. After adequate control of seizures with medication, repeat MR was normal and the prior enhancement was no longer seen. This transient seizure-induced MR enhancement was consistent with ictal or postictal hyperemia and breakdown of the blood-brain barrier and should not be erroneously attributed to mesial temporal sclerosis, encephalitis, tumor, or infarction.
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