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Biomedical subjects

M Brant-Zawadzki

Publications and source records attributed to M Brant-Zawadzki.

At least 19 recordsLinked to original sources
PubMed1992

MP RAGE: a three-dimensional, T1-weighted, gradient-echo sequence--initial experience in the brain.

The authors evaluated a recently developed sequence for magnetic resonance imaging of the brain. The three-dimensional, Fourier-transformed acquisitions require magnetization-prepared 180 degrees radio-frequency pulses and rapid gradient-echo (MP RAGE) sampling. The resulting T1-weighted images were compared with T1-weighted spin-echo (SE) images; both were obtained after paramagnetic contrast material was administered to 33 patients with known or suspected focal brain lesions. Image quality and contrast between gray and white matter were superior with the MP RAGE sequence compared with the T1-weighted SE sequence. The time for obtaining contiguous thin-section (1.3-2.5-mm) images was also comparable, with readily acquired multiplanar reformations obviating additional images. MP RAGE imaging depicted more focal lesions than did T1-weighted SE imaging and matched the number seen with T2-weighted SE imaging. Demonstration of paramagnetic contrast enhancement of lesions was comparable in most cases; however, three lesions showed greater enhancement on T1-weighted SE images and two others were seen only on the T1-weighted SE images. Thus, the MP RAGE sequence may provide an alternative to T1-weighted SE imaging.

Adult↗
PubMed1991

Pitfalls of contrast-enhanced imaging in the nervous system.

This brief review covers the evolving clinical role of paramagnetic contrast agents in magnetic resonance imaging of the central nervous system, with particular emphasis on potential pitfalls. The safety and efficacy of Gd-DTPA is now well-established. Approximately 35-40% of all scans performed in this country now utilize the agent. The major pitfalls center on overinterpretation of the characterization of disease by either enhancement or lack thereof in any particular process.

Central Nervous System Diseases↗
PubMed1991

Multicenter study of gadodiamide injection as a contrast agent in MR imaging of the brain and spine.

To evaluate the safety and efficacy of gadodiamide injection, a nonionic gadolinium chelate complex, in magnetic resonance (MR) imaging of the head and spine, a phase II-III trial was conducted in 439 patients with known or suspected lesions in the central nervous system. All patients received gadodiamide injection in a dosage of 0.1 mmol/kg and were monitored; MR images were evaluated for contrast material enhancement. No serious adverse events or clinically important trends in vital signs, laboratory values, or neurologic status were observed. Gadodiamide injection enhanced or facilitated the visualization of lesions in 266 or 353 patients (75.4%) in whom lesions were shown on unenhanced images, enhanced images, or both; in these 266 patients, the diagnosis was changed in 76 patients (28.6%) and facilitated in 190 patients (71.4%). It is concluded that gadodiamide injection is safe and effective for MR imaging of the head and spine in patients with suspected abnormalities of the central nervous system.

Brain↗
PubMed1990

Preservation of normal cognitive functioning in elderly subjects with extensive white-matter lesions of long duration.

Although deep white-matter brain lesions are seen on magnetic resonance imaging in about one third of elderly subjects, their clinical significance is not known. In 1984, we studied three retired teachers who had extensive deep white-matter brain lesions on magnetic resonance imaging, yet functioned cognitively at an above-average level. Blinded review of 1981 computed tomographic scans revealed patchy white-matter lucencies for two of the subjects. Repeated magnetic resonance imaging in 1987 showed that the deep white-matter brain lesions were at least as extensive as in the initial study. One subject had developed renal failure, while the other two continued to function at a high level with no evidence of cognitive decline or psychiatric or neurologic impairment. The presence of extensive deep white-matter brain lesions for up to 7 years in two subjects whose cognitive, behavioral, and neurologic functioning is unimpaired suggests that deep white-matter brain lesions do not necessarily indicate a clinically significant central nervous system disease process.

Age Factors↗
PubMed1990

Routine MR imaging of the internal carotid artery siphon: 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 siphon, 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↗
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↗