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Biomedical subjects

G Sze

Publications and source records attributed to G Sze.

At least 19 recordsLinked to original sources
PubMed1992

MR imaging of the spinal cord: current status and future advances.

The advent of MR imaging has dramatically altered the evaluation of suspected myelopathy. MR is far less invasive than traditional imaging techniques and often offers a degree of understanding of an abnormality not previously possible. These achievements have closely followed recent technologic advances, such as the development of contrast agents and the introduction of sequences that permit a reduction in both imaging time and artifacts. The current role of MR in the imaging of spinal cord disorders, including intramedullary tumors, infectious and inflammatory myelitis, demyelinating diseases, vascular lesions, trauma, syringomyelia/hydromyelia, and neurodegenerative disorders, is reviewed. While further improvements will undoubtedly occur, the field of spinal MR imaging appears to be entering a maturing phase.

Forecasting↗
PubMed1992

Neuroradiology of the immunosuppressed state.

In recent years, one of the most common reasons for neuroimaging has become the evaluation of the immunosuppressed patient. In this review the radiographic appearances of the common inflammatory and neoplastic conditions affecting the central nervous system in patients with HIV infection, as well as the AIDS-dementia complex, are discussed. Non-AIDS immunocompromised neurologic disease is also examined, with particular emphasis on the effect of various immunosuppressive medications on the brain and spine.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Magnetic resonance imaging in the evaluation of spinal tumors.

Magnetic resonance imaging (MRI), which has recently begun to replace myelography, postmyelography computed tomography (CT), and to some extent, bone scans, has become the procedure of choice in the evaluation of spinal tumors; the applications of MRI in this role are reviewed. In the extradural space, MRI is the most sensitive technique for the detection of tumors in the vertebral bodies. At the same time, it provides superb delineation of suspected thecal sac impingement. In the intradural extramedullary space, MRI is generally as accurate as myelography and postmyelography CT while being noninvasive. Finally, in the intramedullary space, MRI is unquestionably the procedure of choice in the evaluation of suspected cord tumors. In general, MRI has become the best initial procedure in the evaluation of suspected tumors of the spine, regardless of the space in which they may lie; frequently, it is the only required examination.

Humans↗
PubMed1991

Syphilitic meningitis causing paraparesis in an HIV-negative woman.

Syphilitic meningitis, which can occur near the time of secondary syphilis, is frequently asymptomatic. There has been one recent report of an HIV-positive patient who developed syphilitic polyradiculopathy following a recent history of secondary syphilis. We describe an HIV-negative woman in whom paraparesis occurred secondary to syphilitic meningitis. Complete recovery followed a course of high-dose intravenous penicillin therapy, emphasizing the treatable nature of this cause of paraparesis.

Adult↗
PubMed1991

Histologic basis for increased extraocular muscle enhancement in gadolinium-enhanced MR imaging.

Minimal to mild enhancement of skeletal muscles is normally seen on gadolinium-enhanced magnetic resonance images. The enhancement of the extraocular muscles is much more intense than that of other skeletal muscles. The authors investigated the structural features of extraocular muscles that contribute to this increased enhancement. After comparing samples of extraocular muscle and quadriceps muscle, the authors concluded that the rich vascularity and the prominence of extravascular space most probably cause extraocular muscles to demonstrate intense enhancement on gadolinium-enhanced images.

Gadolinium DTPA↗
PubMed1991

Developing spinal column: gadolinium-enhanced MR imaging.

Enhancement characteristics of the normally developing spinal column were examined in magnetic resonance (MR) images obtained in 58 children aged 7 days to 9 years. With a 1.5-T imager, short-repetition-time spin-echo images were obtained before and after the administration of 0.1 mmol/kg gadopentetate dimeglumine. Enhancement of normal bone marrow was seen in all patients aged less than 7 years; it was marked only in patients aged less than 2 years. Enhancement of normal cartilage, seen in all patients aged less than 1 1/2 years, may be the most striking feature of enhanced MR images of the infant spine. Enhancement of both bone marrow and cartilage in children appears to be due to the unusual prominence of vasculature, associated with permeability of the capillary endothelium and a plentiful extravascular space. Although marked and diffuse enhancement of vertebral bodies in adults is often thought to indicate a pathologic marrow state, caution must be used before the same criteria are applied to children.

Age Factors↗
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↗
PubMed1991

Evolution of the infant spinal column: evaluation with MR imaging.

The appearance of the normal lumbar spinal column was examined in spinal magnetic resonance images obtained in 50 pediatric patients aged 2 years or less. The ossification centers of the developing vertebral bodies, the cartilage, and the disks were studied with a 1.5-T imager by using both short- and long-repetition-time spin-echo sequences. Many of the structures of the spine were noted to undergo dynamic changes in appearance, both in signal intensity and in morphologic characteristics, with growth. The vertebrae and cartilage, especially, transform markedly in infancy and proceed through three characteristic stages of evolution. Stage I, from birth to 1 month of age, is characterized by markedly hypointense ossification centers and hyperintense, prominent cartilage. Stage II, from approximately 1 to 6 months of age, is characterized by increasing signal intensity in the ossification centers, progressing from the endplates in, and decreasing prominence of the cartilage, Stage III, from approximately 7 months of age on, is characterized by increasingly rectangular and centrally intense vertebral bodies and diminishing cartilage. The variability of the signal intensities, with that of muscle used as the standard, and morphologic characteristics of different components of the spine at different stages of development can create significant confusion. Careful analysis, however, permits one to follow the evolution of the lumbar spine and to date it on the basis of its appearance.

Cartilage↗
PubMed1991

Magnetic resonance imaging of spinal infection.

The findings on magnetic resonance imaging in various types of spinal infection are described, including disc space infection and osteomyelitis, epidural abscess, paraspinal abscesses, and meningitis. The characteristic appearance of spinal infection on both plain and gadolinium-enhanced magnetic resonance is contrasted with that of the normal spine.

Abscess↗
PubMed1991

Recent advances in spinal magnetic resonance imaging.

The application of recent technologic innovations, such as phase-array coil technology, saturation bands in the field of view, variable bandwidth, new methods of image display, new applications of contrast agents and ultrafast spin-echo imaging, promises to improve even further the scope and versatility of magnetic resonance imaging of the spine. Several of the new methods, such as the fat-saturation and variable-bandwidth techniques, have been applied to imaging the head, but their use in imaging the spine has lagged for various technologic reasons. For other advances, such as phased-array coil technology, minor problems, including prolonged reconstruction time, have yet to be overcome. Still others, such as ultrafast spin-echo imaging, have been developed so recently that they have just begun to enter clinical trials. All of these techniques promise to improve the quality and, in some cases, the speed of spinal magnetic resonance imaging and should allow an even better understanding of the anatomy and pathology of the spine.

Aged↗
PubMed1990

Decompression of epidural metastases from germ cell tumors with chemotherapy.

Epidural cord compression from germ cell tumor metastases is not common. Treatment usually requires high dose corticosteroids with radiation therapy and/or surgical decompression. Three patients with epidural germ cell tumor metastases were treated with cisplatin-based chemotherapy and all three had complete neurologic recovery. Systemic chemotherapy should be considered as initial therapy with corticosteroids for epidural cord compression from metastatic germ cell tumor.

Adult↗
PubMed1990

New applications of MR contrast agents in neuroradiology.

Contrast enhancement has now become an integral part of MR imaging. In this paper, the current uses of contrast agents in MR imaging of both the head and spine are reviewed. In addition, new applications of contrast in MR imaging, including some more current and controversial, are also explored.

Bone Diseases↗
PubMed1990

Emotional facial paresis with striatocapsular infarction.

Emotional facial paresis (EFP) refers to hemifacial paresis of emotionally evoked or spontaneous smiling or weeping with preserved volitional movements of the face. The anatomical location for this phenomenon has been controversial. We report a 15-year-old boy with EFP. Follow-up MRI demonstrated infarction limited to the head of the caudate, putamen and anterior limb of the internal capsule on the contralateral side. This case lends support for selective damage at a striatal or capsular site in the production of EFP.

Adolescent↗
PubMed1990

Calvarial and skull base metastases: comparison of nonenhanced and Gd-DTPA-enhanced MR images.

Fourteen patients with calvarial metastases were studied with magnetic resonance (MR) imaging before and after intravenous administration of gadolinium diethylenetriamine-pentaacetic acid (DTPA) to evaluate the utility of contrast material enhancement for the detection of calvarial metastatic tumor. MR imaging was also performed before and after enhancement in 60 patients for reasons other than evaluation of metastases or calvarial tumor, to determine the apperance of the normal calvaria with enhancement. The normal pattern of fat distribution in the diploic space was typically symmetric. Except for enhancement of diploic veins and meninges near pacchionian granulations, the normal diploic space did not enhance. Calvarial metastases typically enhanced with Gd-DTPA. Enhanced MR images were superior to nonenhanced studies for detecting subtle intradiploic metastases but were inferior to nonenhanced studies for detecting tumor extension into fat-containing areas. Careful comparison of nonenhanced and enhanced MR images is required for complete evaluation of lesions affecting the calvaria and skull base.

Contrast Media↗
PubMed1990

Benign lumbar arachnoiditis: MR imaging with gadopentetate dimeglumine.

MR imaging was performed in 13 patients with benign lumbar arachnoiditis both before and after IV injection of gadopentetate dimeglumine. The arachnoiditis was proved by previous myelography in 12 patients and by noncontrast MR imaging in one patient. The disease was presumably the result of previous myelography and/or surgery. It was characterized as mild in two patients, moderate in two patients, and severe in nine patients. Imaging was performed on a 1.5-T unit, and both short and long TR images were obtained before and after contrast administration. Noncontrast MR images demonstrated changes consistent with arachnoiditis in all patients. After contrast, three patients had no enhancement, three patients had minimal enhancement, three patients had mild enhancement, and four patients had moderate enhancement. In no case did contrast enhancement alter the diagnosis or reveal additional findings that could not be seen on the noncontrast images. Gadopentetate dimeglumine enhancement plays little role in the diagnosis of lumbar arachnoiditis. If used for another reason, however, short TR scans may show enhancement of adherent roots in some cases. In addition, administration of gadopentetate dimeglumine will not cause sufficient enhancement to hinder the detection of arachnoiditis on long TR images and may aid in recognition of adherent roots on short TR images.

Adult↗