PubMed Health⌕ Search

Biomedical subjects

M Brant-Zawadzki

Publications and source records attributed to M Brant-Zawadzki.

At least 19 recordsLinked to original sources
PubMed1999

The syndrome of spontaneous intracranial hypotension.

The authors report four cases of headache and other symptomatology related to the syndrome of intracranial hypotension. They were seen in a routine clinical practice over the past 3 years. The clinical features, magnetic resonance imaging (MRI) findings, and follow-up of these patients are described. Review of the prior literature on the topic is also included. All four patients presented with orthostatic headache syndrome. Three of the four demonstrated diffuse leptomeningeal thickening and enhancement on MRI studies. One subsequently developed a subdural effusion. One patient demonstrated downward displacement of the posterior fossa initially, which resolved on follow-up MRI scanning. Possible pathophysiologies of the syndrome are discussed.

Adult↗
PubMed1996

Fluid-attenuated inversion recovery (FLAIR) for assessment of cerebral infarction. Initial clinical experience in 50 patients.

BACKGROUND AND PURPOSE: Our aim was to evaluate fluid-attenuated inversion recovery (FLAIR) sequence in the diagnosis of cerebral infarction with MRI. METHODS: A retrospective review was undertaken of 50 consecutive MRI studies ordered for suspected cerebrovascular accident. All studies included FLAIR and rapid acquisition with relaxation enhancement (RARE) T2-weighted spin-echo sequences. The two sequences were compared independently by four observers at two different institutions. Detectability of lesions and image quality were scored. RESULTS: Overall, FLAIR sequences proved superior in 10 patients, detecting acute cortical infarcts missed with RARE spin-echo technique in five patients. In five additional patients, improved characterization of chronic infarction and improved detection of microangiopathic deep hemispheric changes were observed. One brain stem infarct was missed with the FLAIR sequence. CONCLUSIONS: FLAIR offers advantages in detection of acute infarcts affecting the cortical ribbon, is a useful, rapid adjunct to conventional T2-weighted spin-echo sequences, and has the potential to replace these in the future.

Artifacts↗
PubMed1996

Fluid-attenuated inversion recovery (FLAIR): clinical prospectus of current and future applications.

A relative weakness of the traditional spin-echo technique, and particularly of the newer "FAST" or "TURBO" spin-echo sequences, has been diminished conspicuousness of lesions affecting the peripheral cortical mantle or those located in the periventricular region. This is a consequence of partial volume effects and high cerebrospinal fluid (CSF) signal adjacent to pathologic regions. Fluid-attenuated inversion recovery (FLAIR) is a magnetic resonance imaging (MRI) sequence that produces strong T2 weighting, suppresses the CSF signal, and minimizes contrast between gray matter and white matter. This effect produces images with significantly increased lesion-to-background CSF contrast and enhances the visibility of lesions as well as their detectability, particularly in the peripheral subcortical and periventricular regions. Applications are evolving, though preliminary reports highlight the superiority of FLAIR in the evaluation of infarction, multiple sclerosis, metastatic disease, tuberous sclerosis, and, possibly, subarachnoid hemorrhage. Early reports also address the application of FLAIR to imaging of the spinal cord. Modified versions of FLAIR are currently being developed; these modifications will further shorten acquisition times and eliminate pulsation artifacts. FLAIR may ultimately supplant conventional spin-echo imaging in routine MR screening of the brain.

Brain Diseases↗
PubMed1995

Spinal nomenclature.

There has been a proliferation of differing terms, even among practicing surgeons. A morphologically based nomenclature may be needed for radiologic purposes, whereas a more histopathologic terminology would be desirable for surgical descriptors. Whichever approach is undertaken, the true radiologic-surgical correlation of disc abnormalities within the spine is doomed to failure without agreement on some type of standard nomenclature. A review of the problem and potential solutions are suggested.

Humans↗
PubMed1994

Improved MR angiography: magnetization transfer suppression with variable flip angle excitation and increased resolution.

Results at conventional magnetic resonance (MR) angiography were compared with results at MR imaging with a sequence combining optimized magnetization transfer (MT) saturation and tilted optimized nonsaturating excitation (TONE). Forty images were obtained of five healthy volunteers and five patients with known intracranial vascular abnormalities (four men and six women, aged 22-72 years). Four blinded readers found improved vessel penetration, enhanced vessel-to-background contrast, the better vessel detail in the MT saturation-TONE images than in the conventional three-dimensional time-of-flight MR angiograms.

Adult↗
PubMed1993

Use of the magnetic resonance contrast agent gadodiamide in the central nervous system. Results of a multicenter trial.

To investigate the safety and efficacy of the low-osmolar, nonionic contrast agent, gadodiamide injection (Omniscan, Sanofi Winthrop Pharmaceuticals, New York, NY), for magnetic resonance imaging (MRI) of the head and spine, a multicenter study involving 439 patients was done at 15 centers as part of a Phase II/III clinical trial. Unenhanced MRI scans were obtained after which the patients were injected with 0.1 mmol/kg gadodiamide, and the MRI was repeated. The patients' vital signs were monitored, and laboratory studies were conducted. Neurologic status was examined before and after the study. The images were evaluated for contrast enhancement. No patient had any significant adverse event or serious change in clinical status. Abnormalities were found in 80% (351) of all patients studied, and it was found that, in 75% (266) of these, the postgadodiamide injection images were improved or facilitated visualization of lesions compared with preinjection images. The investigators believe that, based on the results of this study, gadodiamide injection is safe and effective for imaging the head and spine. They suggest that future studies further assess and compare the safety parameters of gadodiamide injection with those of other nonionic and ionic gadolinium ligands.

Central Nervous System Diseases↗
PubMed1993

Magnetic resonance angiography of cervicocranial dissection.

BACKGROUND: A retrospective study of five patients with the clinical or magnetic resonance-based diagnosis of carotid dissection was done. Clinical data, imaging studies, treatment, and outcome were reviewed. The potential applicability of three-dimensional time-of-flight magnetic resonance angiography in these settings was evaluated. SUMMARY OF REPORT: This modality reliably showed vascular abnormalities and focal, segmental, or aneurysmal dilatation when correlated with conventional angiograms in three patients. Turbulence and magnetic susceptibility at the acute turn of the carotid in the petrous canal led to a false-positive diagnosis on magnetic resonance angiography in one patient (in whom subtle fibromuscular hyperplasia was found with conventional angiography but missed with magnetic resonance angiography). CONCLUSIONS: When combined with appropriate clinical signs, magnetic resonance imaging and magnetic resonance angiography can reliably establish the diagnosis of carotid dissection. Pitfalls of magnetic resonance angiography are discussed.

Adult↗
PubMed1993

MR imaging of the brain in patients with AIDS: value of routine use of i.v. gadopentetate dimeglumine.

OBJECTIVE: A prospective study was conducted to explore the value of routine administration of IV gadopentetate dimeglumine for MR imaging of the brain in patients with AIDS. SUBJECTS AND METHODS: Over a 19-month period, MR images of the brain in 51 consecutive AIDS patients were obtained routinely both with and without IV gadopentetate dimeglumine. Unenhanced and contrast-enhanced images from the resulting 63 studies were viewed together. Findings were classified into one or more of three categories: normal, mass or focal lesions, or white matter disease. The number of focal or mass lesions was recorded. Lesion conspicuity on the unenhanced and enhanced images was compared. Ventricular enlargement was also graded. Available medical records and laboratory data of the patients were reviewed. RESULTS: Of the 63 MR studies reviewed, 39 (62%) were abnormal. In no case was a normal unenhanced MR study rendered abnormal after the administration of gadopentetate dimeglumine. Overall, T2-weighted images showed twice as many focal or mass lesions than contrast-enhanced T1-weighted images did. Most lesions detected on the T2-weighted images did not show enhancement with contrast material. White matter disease was the most common abnormality detected. The group of patients with white matter disease also had the highest occurrence of ventriculomegaly. CONCLUSION: Our study does not support the routine use of gadopentetate dimeglumine for MR imaging of the brain in patients with AIDS. Our experience emphasizes the importance of a normal T2-weighted image.

AIDS Dementia Complex↗
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↗