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Biomedical subjects

M Brant-Zawadzki

Publications and source records attributed to M Brant-Zawadzki.

At least 37 records · Page 2Linked to original sources
PubMed1990

Routine MR imaging of the internal carotid artery siphone: angiographic correlation with cervical carotid lesions.

This study correlates the appearance of the cavernous segment of the carotid artery on MR images with the presence of significant stenosis or occlusion of the cervical carotid artery as seen on angiograms in 100 patients who had brain MR imaging and arteriography within a 1-week period. Four patients demonstrated isointense signal within the carotid artery's cavernous segment; two of these findings correlated with complete carotid occlusion as seen angiographically, while partial compromise was seen angiographically in the other two. Four other patients had variable signal intensity and irregularity of the luminal outline in the carotid siphone, correlating with angiographic evidence of atheromatous disease in three patients and of dissection in one patient. The demonstration of normal signal void within a normal-appearing cavernous segment of the internal carotid artery in the remaining 92 patients correlated with absence of significant stenosis within the cervical segment in 86 patients. In the remaining six, significant disease of the internal carotid artery was found. Isointensity within the intracranial carotid artery can indicate either complete occlusion or very slow flow. Therefore, angiography is still necessary to completely exclude potentially treatable disease that produces very slow flow leading to isointensity. The presence of normal flow void in the intracranial segment does not exclude significant compromise of the cervical segment of the carotid artery.

Adolescent↗
PubMed1989

Acute neck pain due to tendonitis of the longus colli: CT and MRI findings.

Calcific retropharyngeal tendonitis is an under-recognized cause of acute cervical pain produced by inflammation of the longus colli muscle. Although the clinical presentation may mimic more serious disorders, the diagnosis can be established radiographically by identification of prevertebral soft tissue calcification and swelling. Six patients with typical signs and symptoms of retropharyngeal tendonitis are presented. All were evaluated with plain films, four with CT and one with MRI. The pathognomonic finding of amorphous calcification anterior to C1-2 with associated asymmetric soft tissue swelling was clearly demonstrated by CT. Diffuse swelling of the longus colli muscle was shown as prominent high signal in the prevertebral region by T2 weighted MRI.

Acute Disease↗
PubMed1989

Transluminal angioplasty for treatment of intracranial arterial vasospasm.

Percutaneous transluminal angioplasty for treatment of intracerebral arterial vasospasm is now being performed in selected cases. Thirty-six vascular territories in 13 patients, ranging in age from 15 to 73 years, have been treated with a new silicone microballoon device. This balloon has allowed mechanical dilatation of segmental and diffuse areas of spastic intracerebral blood vessels less than 1 mm in diameter with return to normal luminal diameter. Follow-up angiography has documented improved cerebral perfusion without return of spasm. In 10 patients (77%), vasospasm was due to subarachnoid hemorrhage following rupture of an intracranial aneurysm. In three patients (23%), spasm with resultant neurological decline occurred during detachable balloon embolization therapy for treatment of an aneurysm. In each case, the vessel caliber returned to normal size following balloon dilatation. In nine (69%) of the 13 cases, balloon dilatation resulted in improvement of neurological function within minutes to hours following the procedure. Transluminal angioplasty techniques may offer an alternative form of therapy in the management of symptomatic arterial vasospasm.

Adolescent↗
PubMed1988

Absence of white matter changes on magnetic resonance imaging in children treated with CNS prophylaxis therapy for leukemia.

Previous studies have shown that magnetic resonance imaging (MRI) is sensitive to white matter changes in children receiving cranial radiation of 3000 cGy or greater. The current study used MRI to investigate the integrity of white matter in children receiving 1800 to 2400 cGy of cranial radiation. Ten survivors of acute lymphoblastic leukemia (ALL) who received intrathecal methotrexate (MTX) and either 1800 or 2400 cGy of cranial radiation were studied with MRI and neuropsychologic testing. Magnetic resonance (MR) scans were normal in nine of ten patients. One patient had prominent and asymmetrical lateral ventricles and mildly enlarged cortical sulci. White matter tracts were normal in appearance. However, seven of nine children had below average intellectual functioning. Results indicate that children receiving less than 2500 cGy of cranial radiation fail to show white matter changes on MRI, despite evidence of cognitive impairment.

Brain↗
PubMed1988

Familial cavernous malformations. Diagnostic potential of magnetic resonance imaging.

Three patients from the same family underwent operations for neurological symptoms related to vascular lesions that proved on pathological examination to be cavernous malformations. Two of the lesions were intracranial and one was in the thoracic spine. Five other family members have also had neurological symptoms; three of these five were studied with cerebral magnetic resonance imaging and computed tomography. The vascular malformations seen on computed tomography scans were more clearly delineated by magnetic resonance images, and in one case, magnetic resonance images identified intracerebral vascular pathology not demonstrated by computed tomography. Magnetic resonance images in two neurologically normal family members showed no abnormalities. We conclude that in this family, magnetic resonance imaging was superior to computed tomography in identifying and delineating vascular malformations of the central nervous system.

Adult↗
PubMed1987

Giant intracranial aneurysms: MR imaging.

Fifteen patients with giant intracranial aneurysms were examined with magnetic resonance (MR) imaging, computed tomography (CT), and angiography. MR imaging revealed a rounded extraaxial mass with evidence of intraluminal blood flow in 12 of the 15 cases. Signal void within the lumen was seen in all 12 of these cases. Other flow effects, such as even-echo rephasing, were seen in some cases. Complete thrombosis was seen in three giant aneurysms in which high signal intensity on T1- and T2-weighted images filled the lumen, and no flow effects were seen. Partial thrombosis was detected in four aneurysms as persistent areas of medium to high signal intensity within the lumen on T1- and T2-weighted images. In five cases, the cause of the intraluminal signal that was present was difficult to determine. The ability of MR to indicate flow within the lumen in 12 of 15 cases provided for greater diagnostic confidence than with CT, which was strongly suggestive of an extraaxial tumor in nine patients. Calcification of the wall of the aneurysm was better detected with CT.

Adult↗
PubMed1987

MR imaging of paragangliomas.

MR imaging of 15 paragangliomas in 10 patients was compared with CT of 13 of the lesions in eight patients. All lesions were confirmed with angiography. All lesions were detected by MR and CT with the exception of one small glomus tympanicum tumor that was seen only in retrospect with MR. CT better demonstrated subtle osseous changes of the skull base and the relation of the tumor to the middle ear structures. MR better demonstrated the relation of the tumor to the adjacent internal jugular vein and carotid artery. The paragangliomas had a characteristic MR appearance based on their vascularity. Serpiginous areas of signal void representing high vascular flow were interspersed among areas of high signal intensity caused by slowly flowing blood and tumor cells. This "salt-and-pepper" pattern was seen in all lesions greater than 2 cm in maximal dimension. MR was therefore able to accurately characterize the tumors as highly vascular. Multiplanar imaging and good tissue contrast and anatomic detail permitted display of the relations of these neoplasms to surrounding carotid sheath vessels and to intracranial structures better than did CT. In this experience, the MR appearance of paragangliomas was quite characteristic and differed markedly from meningiomas, neuromas, and metastatic disease of the skull base.

Carotid Body Tumor↗
PubMed1987

MR imaging of intracranial tuberous sclerosis.

The role of MR in evaluating tuberous sclerosis is reviewed in 15 patients. These studies were compared with CT scans, which were available in 14 patients. Four characteristic findings were noted on the MR images obtained. Subependymal nodules projecting into the lateral ventricles were seen in 12 of 15 patients on T1-weighted images. This was the most specific finding. Distortion of the normal cortical architecture was seen in 10 of 11 patients in whom T1-weighted images were obtained using a 256 X 256 matrix. These foci corresponded to multiple cortical areas of increased signal on T2-weighted images. Dilated ventricles were seen in five patients. In one patient, a known astrocytoma showed increased signal on the T2-weighted images, allowing differentiation from a benign subependymal nodule. MR depicted the cortical hamartomas more completely than did CT. The MR scans were abnormal in all cases, and a diagnosis could be confidently made in all 11 cases scanned using a 256 X 256 matrix. Our preliminary experience suggests that MR will at least equal and probably exceed CT, both for sensitivity and specificity, given the use of a 256 X 256 matrix.

Adolescent↗
PubMed1987

Magnetic resonance imaging of cerebral ischemia and infarction.

In summary, then, the major strength of MRI in evaluating cerebral ischemia is in the sensitivity that this methodology provides for detection of the disease process. However, it must be realized that edema is a nonspecific event related to various insults affecting the brain. There is still an uncertain capability of MRI in separating acute hemorrhagic from acute ischemic events. The superior sensitivity of MRI should help in investigations aimed at evaluating various forms of intervention in acute ischemia. Because some of these acute changes are at the biochemical rather than morphologic level, proton MRI alone probably will be insufficient to explore numerous variables. For this reason, the potential offered by MRS in cerebral ischemia research and in clinical settings is important. Vascular imaging is relatively complex. Several techniques show promising results but at the present time have poor resolution in comparison to ultrasound and angiography. For the immediate future, they will remain investigational.

Animals↗
PubMed1986

Evaluation of patients with multiple sclerosis by evoked potentials and magnetic resonance imaging: a comparative study.

We compared the diagnostic usefulness of evoked potential (EP) studies and magnetic resonance imaging (MRI) in the evaluation of 27 patients with definite or probable multiple sclerosis (MS). MRI scans demonstrated multiple lesions in 21 patients whereas EP studies showed multiple abnormalities in 14 patients (4 of whom had only somatosensory EP abnormalities). Eighteen patients had similar MRI and EP results (e.g., normal or multiple abnormalities), 8 had multiple abnormalities shown by MRI but normal or single-modality abnormal EPs, and 1 had multiple abnormal EPs but a normal MRI scan. There was no significant difference in the sensitivity of the two techniques in detecting multiple lesions in the patients with definite MS, whereas among those with probable MS, MRI had a significantly higher yield. Seventeen patients showed clinical evidence of posterior fossa involvement, 6 patients had abnormal brainstem auditory evoked potentials (BAEPs), and 4 patients had areas of increased signal intensity revealed by MRI of the brainstem. There was no clinical evidence of brainstem involvement in 2 patients with BAEP abnormalities, 2 with an abnormal posterior fossa shown by MRI, and one patient with abnormalities shown by both BAEP and MRI. We conclude that MRI is more sensitive in detecting multiple lesions than are multimodality EP studies, but that BAEP assessment may be slightly more sensitive than MRI in detecting brainstem lesions.

Adult↗
PubMed1986

Spin-echo MR imaging of intracranial hemorrhage.

This retrospective study was performed to describe the appearance of intracranial hemorrhagic lesions on magnetic resonance (MR) imaging at 0.35 tesla using the spin-echo technique, and define the present clinical role of MRI in this particular pathology. Forty-eight examinations of forty-three patients with forty-seven intracranial hemorrhagic lesions (39 true hematomas and 8 hemorrhagic lesions mixed with other tissues) were reviewed for this study. Comparative CT studies were available for all the patients. In our limited experience with acute hematomas (less than 3 days old), low or isointense signal was seen with a short TR (0.5 s), but a relative increase in signal intensity was observed with a long TR (2.0 s). This appearance of acute hematoma was not specific. Chronic hematomas (more than 3 days old) were imaged as foci of bright signal intensity on both short and long TR. This pattern was characteristic of chronic hematoma. With a short TR (0.5 s), two hemorrhagic lesions (5 and 7 days old) were displayed as an isointense signal surrounded by a rim of high intensity signal. This peripheral zone most likely represented liquefaction at the clot's periphery and the initial formation of methemoglobin. T1 and T2 relaxation times were found to be very long for acute hematomas (first two days). T1 values of chronic hematomas (more than 3 days old) were comparatively short and in the same range as T1 of white matter. T2 values of chronic hematomas decreased also but remained very long.

Acute Disease↗
PubMed1986

Brain radiation lesions: MR imaging.

This retrospective study was performed to assess the capability of magnetic resonance (MR) to depict and characterize diffuse and focal radiation lesions in the brain using the spin-echo technique. The MR images of 55 patients who had undergone radiation therapy were reviewed. Comparative computed tomography (CT) studies were available for all the patients. Normal white matter was chosen as reference tissue for the quantitative comparison of signal intensities. Radiation lesions (identified in eight patients) were seen as regions of high signal intensity on the sequence with a long repetition time (TR) (2.0 sec) and showed no difference in signal compared with white matter when the TR was short (0.5 sec). Nonspecific prolongation of T1 and T2 relaxation times was measured in such lesions. In one patient, subependymal tumor spread, demonstrated by contrast-enhanced CT, was missed on MR images, masked by the adjacent abnormal signal owing to radiation effects. Recurrent or residual brain tumor could not be distinguished from radiation brain necrosis either by CT or by MR imaging. It is concluded that MR can depict radiation lesions with great sensitivity but is not very helpful for discrimination between recurrent or residual brain tumor, radiation necrosis, and other brain lesions.

Adolescent↗
PubMed1986

Acute experimental cerebral ischemia: MR enhancement using Gd-DTPA.

The effects of a paramagnetic contrast agent, gadolinium-DTPA (Gd-DTPA), on magnetic resonance (MR) imaging of acute cerebral ischemia was investigated in a feline model of middle cerebral artery occlusion. Imaging was performed both before and after administration of an intravenous dose of 0.2 mmol/kg of Gd-DTPA. The animals were then sacrificed for pathologic correlation. No changes in intensity or relaxation times were noted before or after Gd-DTPA administration in two animals with 2 hours of occlusion. Infarcts were noted before and after contrast enhancement in all six cats with ischemia of greater than 16-hours duration. Gd-DTPA caused significant increase in intensity of infarct but not in that of normal cerebral tissue. Rapid enhancement was visible in infarcts of 16-24 hours, but such enhancement was slower in infarcts of 72-168 hours, presumably owing to slowed inflow caused by increased vasogenic edema in the latter group. Contrast enhancement of acute cerebral ischemic lesions with Gd-DTPA offers no improvement in sensitivity of MR imaging, although the conspicuity of the lesion may be improved. Additionally, contrast media may provide potential temporal and pathophysiological data for better characterization of cerebral ischemia.

Animals↗