Hyperacute intraventricular hemorrhage revealed by gadolinium-enhanced MR imaging.
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Acute Disease↗
Biomedical subjects
T el Gammal
Publications and source records attributed to T el Gammal.
Early bilateral radiation-induced optic neuropathy with follow-up MRI.
Most documented cases of radiation-induced optic neuropathy are unilateral and occur more than 1 year after radiotherapy to the sellar region. We describe a patient with bilateral radiation optic neuropathy 3 months following the completion of radiotherapy. MRI 13 months after the onset of visual failure showed bilateral optic atrophy with residual gadolinium enhancement.
Aged↗
MR myelography: imaging findings.
MR myelography, heavily T2-weighted fast spin-echo imaging with fat suppression, enhances the signal intensity of CSF with subtraction of the surrounding background signal. Krudy [1], who first described the technique, used multiple projections per examination. We illustrate the findings in 80 patients who were examined with a modified MR imaging technique that provides increased spatial resolution and uses a single coronal sequence after the conventional MR study. This report illustrates the usefulness of MR myelography in cases of spinal stenosis or spinal block, in both the lumbar and thoracic regions.
Adolescent↗
MR cisternography: initial experience in 41 cases.
PURPOSE: To present our initial experience with MR cisternography, an application of fast spin-echo MR with fat suppression, and compare it with routine MR cranial studies in the evaluation of the subarachnoid cisterns and their contents. METHODS: MR cisternography is a heavily T2-weighted fast spin-echo technique with high spatial resolution; it uses fat suppression and video reversal of the images. A small number of individual sections (two to four) are compressed into a composite image by a maximum-intensity projection algorithm, providing better depiction of anatomy in three dimensions. MR cisternography enhances the signal intensity of the cerebrospinal fluid (CSF) with suppression and subtraction of the background. A total of 41 patients were examined during a period of 6 months. MR cisternography was performed as an additional one (n = 31) or two (n = 10) sequences after conventional MR study. RESULTS: Twenty-one cases of disease were examined by MR cisternography, including 8 neoplasms, 4 CSF fistulas, and 3 large intracranial aneurysms. MR cisternography provided information unavailable by conventional MR studies in 17 cases. These included visualization of fistulous tracks in patients with CSF rhinorrhea, origin of a large suprasellar aneurysm, an additional loculus of a posterior fossa aneurysm and its relation to surrounding structures, and proper location of three tumors (intraaxial versus extraaxial). Clear depiction of the pituitary gland separate from the cavernous sinus was noted in 60% of the cases, and a new observation of a CSF sleeve around the third nerve in the posterior cavernous sinus was made in 85% of the cases. CONCLUSION: MR cisternography is superior to conventional MR studies in depicting anatomic structures within the subarachnoid spaces. This technique is recommended in the evaluation of cranial CSF fistulas and suprasellar and posterior fossa masses and in diagnosis of intraaxial versus extraaxial location of intracranial tumors.
Adolescent↗
Paragangliomas of the neck.
Between 1967 and 1990 inclusive, 28 patients with paragangliomas of the neck were diagnosed at the University of Alabama at Birmingham Affiliated Hospitals. There were 11 men and 17 women, whose ages ranged from 12 to 76 years (mean, 47 years). Tumor locations included the carotid bodies (19 cases), the vagus nerves (three), supraglottic larynx (two), the left lateral pharyngeal wall (one), posterior to the right jugular vein (not otherwise defined) (one), subcutaneous neck tissue (one), and a cervical lymph node with unknown primary (one). Diagnostic workup included angiography (23 cases) with preoperative embolization (three), computed tomography (one), magnetic resonance imaging (two), and urinary catecholamine assay (four). All 28 patients underwent resection of the lesions. Cranial nerve damage occurred in 11 patients (39%). There were no perioperative deaths or cerebrovascular accidents, although one of two saphenous vein grafts became thrombotic after carotid body tumor resection.
Adolescent↗
Persistent infantile odontoid process: a variant of abnormal atlantoaxial segmentation.
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Adolescent↗
Correlates of brain edema in uncontrolled IDDM.
Blood glucose, plasma sodium, bicarbonate (HCO3-), vasopressin, and hematocrit were monitored before and during treatment in patients with uncontrolled insulin-dependent diabetes mellitus (IDDM). These parameters were correlated with simultaneous serial cranial computed tomography readings of brain edema. Six of seven patients had positive computed tomography readings for brain edema on admission. Initial brain edema correlated directly with blood glucose (r = 0.79, P = 0.033) and inversely with HCO3- (r = -0.76, P = 0.047). At 6 h, brain edema still correlated with acidosis (HCO3-; r = -0.79, P = 0.033) but no longer with blood glucose. At that time, however, brain edema correlated with the rate of change in blood glucose (r = 0.915, P = 0.005). Results of interactive stepwise regression analysis suggest that the change in the calculated effective plasma osmolality plays a predominant role in the progression of brain edema during therapy (r = 0.995, P less than 0.001). Thus, although hyperglycemia and acidosis probably predispose to diabetic brain edema, osmotic factors may be major predictors of its evolution. No relationships were detected between brain edema and initiation of insulin therapy, plasma vasopressin, or changes in hematocrit. The factors responsible for initial brain edema and its progression, statistically identified in this study, require reassessment of common theories that attribute brain edema exclusively to therapy.
Adolescent↗
Lyme neuroborreliosis manifesting as an intracranial mass lesion.
Lyme neuroborreliosis is one of the chronic manifestations of Lyme disease and is caused by the neurotropic spirochete, Borrelia burgdorferi. Two of the three stages of Lyme disease potentially involve the central nervous system: a second stage that may manifest as meningitis, cranial neuritis, or radiculoneuritis; and a third stage, or chronic neuroborreliosis, with parenchymal involvement. The tertiary stage may mimic many conditions, including multiple sclerosis, polyneuropathy, viral encephalitis, brain tumor, vasculitis, encephalopathy, psychiatric illness, and myelopathy. We report a 10-year-old child with signs, symptoms, and radiological manifestations of intracranial mass lesions, without previously recognized manifestations of Lyme disease. This proved to be Lyme neuroborreliosis, documented by histological and serological examination, which responded well to antibiotic therapy. The need to establish a tissue diagnosis of intracranial mass lesions is emphasized, and the utility of a computed tomographic-guided stereotactic system for this purpose is discussed.
Biopsy↗
Scalp pilomatrix carcinoma as an extra-axial mass.
We report the CT, MRI, and angiographic findings in a case of pilomatrix carcinoma that had invaded the temporal bone and presented itself as an extra-axial mass. Even though bone destruction was better shown with CT, the tumor mass with its meningeal and tentorial extension was seen more clearly with MRI. The arteriogram demonstrated a unique vascular supply from the external carotid artery.
Humans↗
Conventional MR neuroangiography.
MR angiography of the brain plays an important role in the diagnosis of vessel thrombosis and dissection, giant aneurysms, and occult vascular malformations. This essay highlights some of the features of the intra- and extracranial circulation that make conventional MR neuroangiography valuable in the demonstration of vascular anatomy and vascular disease.
Brain Neoplasms↗
MR of uncommon congenital and vascular lesions of the intracranial visual pathways.
The MR findings of two patients with rare congenital abnormalities of the optic pathways are reported and illustrated, including one case of unilateral aplasia of the optic chiasm, tract, and visual radiations and another patient with anophthalmos. In three other patients with unusual vascular causes of visual disturbance, MR was important in early establishment of an accurate diagnosis and had consequent implications for decisions regarding further patient management.
Adult↗
Osmoregulation of vasopressin in diabetic ketoacidosis.
Osmoregulation of arginine vasopressin (AVP) is altered in diabetic ketoacidosis (DKA). With hyperglycemia, the AVP-plasma sodium (PNa) curve is displaced to the left, whereas the AVP-osmolality (Posm) curve is displaced to the right. The shift in the Na curve is explained by either resetting of the Na set point or by glucose acting as a nonpermeable solute, substituting for Na. Conversely, putative unmeasured solutes that, like urea, fail to affect AVP have been postulated to account for the right shift in the AVP-Posm curve. Therefore the respective roles of Posm = sigma [Xi] and plasma tonicity (Pton = sigma [sigmaiXi]), i.e., the sum of concentrations of all solutes [Xi] corrected (Pton) or not (Posm) for their relative cell permeability (sigma i), were studied in DKA. Indeed, Posm = sigma [Xi] exceeds Pton = sigma [sigma iXi] in DKA, since sigma i less than 1 for glucose. Potential determinants of AVP release (Posm, Pton, and PNa) were monitored in 7 patients with DKA. Conventional correlation analysis and two-dimensional (2D) graphs reproduced the paradox of an opposite shift in PNa and Posm set points for AVP release. However, by using the concept of tonicity instead of osmolality, 3D plots instead of 2D graphs, and multiple regressions instead of correlations, the AVP-PNa and AVP-Pton curves did not appear displaced. The concept of tonicity resolved the paradox of both osmolality and Na thresholds reset in opposite directions. Indeed, in states where a solute like glucose (with sigma less than 1) contributes substantially to plasma osmolality, Posm measured in vitro by the osmometer greatly exceeds Pton perceived in vivo by the osmoreceptor.
Adolescent↗
MR imaging in patients with intractable complex partial epileptic seizures.
Detailed neurologic studies, high-field-strength MR imaging, and CT scanning were performed preoperatively in 53 patients with intractable complex partial seizures who underwent surgical treatment for epilepsy. Macroscopic structural (tumoral or vascular) lesions were found in 28% of patients. The remainder had pathologic findings consistent with mesial temporal gliosis. Tumors were found in 22% of the patients and were benign or of low-grade malignancy in every case. MR was accurate in the preoperative diagnosis of structural lesions, including very small occult tumors and cryptic vascular malformations. In patients with mesial temporal gliosis, there was correlation between the MR observation of a unilaterally dilated anterior temporal horn and the EEG-identified seizure focus and side of temporal lobectomy. However, MR demonstrated T2-weighted signal abnormalities correlating with the epileptogenic focus in only 8% of cases of mesial temporal gliosis. MR provided useful information in 28% of patients who underwent surgery for refractory complex partial epilepsy. MR obviated invasive EEG monitoring in 93% of the patients with structural lesions. MR was useful in only 8% of the patients with pathologic changes of mesial temporal gliosis.
Adolescent↗
Frequency and variation of the posterior pituitary bright signal on MR images.
Sagittal T1-weighted series with 3-mm sections have routinely been used for all cranial MR studies at our institution. It was apparent from examining these studies that the rate of occurrence of a normal posterior pituitary bright signal was lower than has been previously reported, particularly in older patients. This prompted both a retrospective and a prospective review and analysis of the posterior lobe bright signal in three patient categories. The overall frequency of posterior pituitary bright signal and the influence of sex and age were evaluated in one category. An age-related statistically significant decline in the frequency of posterior pituitary bright signal was found, with a decline rate of approximately 1% per year. An evaluation of the occurrence of anatomic variation in the location of posterior lobe bright signal was made in a second group of 1500 patients. Abberrant location of the posterior lobe was found to be uncommon and was seen most frequently in patients with a sellar fossula. Temporal variation in the presence or absence and size of the posterior lobe bright signal was evaluated in a third group of 36 patients who had at least two MR examinations available for review. Follow-up MR study showed an obvious posterior lobe bright signal in 8% of these patients for whom no bright signal was apparent at the time of initial examination. Loss of the posterior lobe bright signal was apparent in another 25% of patients. A significant change in size of the bright signal was apparent in 19% of patients within this category. Our results indicate that variation in the bright signal of the posterior pituitary lobe should be expected as a normal physiological occurrence.
Adolescent↗
Hallervorden-Spatz syndrome: clinical and magnetic resonance imaging correlations.
Two women with a presumptive diagnosis of Hallervorden-Spatz syndrome had a combination of dystonia and parkinsonism. One had retinitis pigmentosa. Neuropsychological testing revealed decreased verbal fluency and visuoconstructional and motor deficits. Magnetic resonance imaging performed with a high-field-strength unit (1.5 Tesla) showed striking abnormalities in the globus pallidus bilaterally ("eye-of-the-tiger" sign). Magnetic resonance imaging may prove useful in the diagnosis of Hallervorden-Spatz syndrome.
Adult↗
Detection of cerebral vasculopathy in sickle cell disease using transcranial Doppler ultrasonography and magnetic resonance imaging. Case report.
We describe a case of homozygous sickle cell anemia in which noninvasive transcranial Doppler ultrasonography and magnetic resonance imaging were used to detect angiographically documented occlusive lesions of intracranial arteries.
Anemia, Sickle Cell↗
MR imaging of Chiari II malformation.
High-field-strength MR imaging was performed in one patient with Chiari III and 19 patients with Chiari II malformations. The MR features were compared with descriptions in the literature and correlated with previously described surgical and postmortem findings and with the results of previous radiologic investigations in this group of patients. Several new observations were apparent from the MR examinations. In 75% of the 20 cases, the underdeveloped tentorium with a wide incisura allowed inferior displacement of the medial posterior cerebrum, which appeared closely applied to a flattened aspect of the superior cerebellum. Previously reported CT descriptions of "pseudotumor of the tentorium" and "towering cerebellum" may be more related to the technique of the radiologic examination than to true upward herniation of the cerebellum. Elongation of the mesencephalon with increase in the mamillopontine distance was present in the majority of our cases and has not been previously emphasized. Some patients had atypical changes or appeared to be borderline cases between the Chiari I and Chiari II categories of malformation, and MR provided considerable diagnostic assistance in these cases. The noninvasive, in vivo evaluation of MR contributed a great deal to our further understanding of this congenital Chiari malformation.
Adolescent↗
Hematogenous spinal leptomeningeal metastasis: a unique CT enhancement pattern.
A distinct CT enhancement pattern of leptomeningeal metastasis from a systemic malignancy is described, corresponding to the pathologic and myelographic patterns of this entity. The uniform total subarachnoid enhancement, simulating intrathecal contrast, heralded sheetlike tumor proliferation along the surface of the spinal cord in an asymptomatic patient. Since the majority of hypervascular intraspinal abnormalities show focal enhancement with intravenous contrast, recognition of this pattern may provide unique clinical information.
Child, Preschool↗