Search PubMed⌕ Search

Biomedical subjects

J A Brunberg

Publications and source records attributed to J A Brunberg.

At least 91 records · Page 5Linked to original sources
PubMed1988

Pediatric musculoskeletal magnetic resonance imaging.

MRI has demonstrated clinical applicability and improved diagnostic capability in the musculoskeletal system to a degree rivaling its success in the neurologic system. For certain regions such as the joints, the superficial nature of these structures is ideal for the application of localized radiofrequency coils, enabling considerably improved signal, spatial resolution, and detectable contrast. The multiplanar capability is often invaluable in assessing such regions as the weight-bearing surfaces of the hips. It has been shown to be the most sensitive single test for diagnosing avascular necrosis, and has yielded very high resolution images of the internal architecture of the joints and soft tissues in an entirely noninvasive manner and without the need for the administration of exogenous contrast agents. Short TE images are quite useful in evaluating fatty background regions of interest, such as the bone marrow and subcutaneous tissue, whereas long TR and TE studies are frequently more suitable for soft tissue pathology. The lack of ionizing radiation and the continued failure of intensive research to disclose any deleterious effects at the levels used for clinical diagnostic imaging make this tool especially appealing for application to the pediatric population. With the continual development of new pulsing sequences, contrast agents, and further advances in imaging/spectroscopic correlation, magnetic resonance imaging of the musculoskeletal system is ensured of a solid role in the clinical diagnostic evaluation of the pediatric population.

Bone Diseases↗
PubMed1987

Spinal and paraspinal neurofibromatosis: surface coil MR imaging at 1.5 T1.

Twelve patients with neurofibromatosis affecting the spine and paraspinal regions were examined with magnetic resonance (MR) imaging performed using a 1.5-T magnet, surface coils, and spin-echo pulse sequences. In all 11 patients with neurofibromas, these tumors had slightly greater signal intensity than muscle on T1-weighted images and markedly increased signal intensity on T2-weighted images. In seven patients central areas of decreased signal intensity within the neurofibromas were demonstrated on T2-weighted images. In one patient these central areas corresponded pathologically to relatively fibrous components of the tumors surrounded by myxoid matrix. Five patients had extensive plexiform neurofibromatosis, one had lateral meningoceles, one had a neurofibrosarcoma, three had extradural spinal cord compression, and two had cystic intramedullary tumors of the spinal cord. The ability to obtain high-resolution, multiplanar images in a noninvasive fashion makes surface coil MR imaging an ideal technique for evaluating neurofibromatosis involving the spinal cord, spinal canal, and paraspinal soft tissues.

Humans↗
PubMed1986

1.5-T surface-coil MRI of the knee.

Five normal knees and 20 knees with suspected abnormalities involving the menisci or articular surfaces were examined with high-resolution surface-coil MRI. Surgical correlation was available in 15 cases. Signal-to-noise ratios were optimized using a field strength of 1.5 T and a round 7.6-cm surface coil. Spatial resolution was maximized by using fields of view reduced to as small as 8 cm. Separate examinations of the medial and lateral joint compartments were performed with the surface coil positioned vertically adjacent to the meniscus of interest. Ten meniscal tears were identified using sagittal and coronal images. T1-weighted images were adequate to detect most meniscal tears, and T2-weighted images were useful for providing an "arthrogram effect" in the presence of a joint effusion. Extrameniscal lesions that were examined included osteonecrosis of the femoral condyle, subchondral cysts, rheumatoid arthritis, degenerative arthritis, and anterior cruciate ligament tears. MRI was useful in determining the integrity of articular cartilage overlying defects in the subchondral bone and in detecting gross cartilage lesions in arthritis, but was less sensitive than arthroscopy in evaluating moderate changes in the hyaline cartilage.

Arthritis, Rheumatoid↗
PubMed1978

Visual evoked potentials during hypothermia and prolonged circulatory arrest.

Visual evoked potentials were recorded in eight children during hypothermia and circulatory arrest. The potentials were lost in all children recorded in late arrest. The evoked potential is a more sensitive indicator of CNS stress as provoked by combined hypothermia and hypoxia than is the EEG. EEG activity persisted in six of the eight children in this series even during circulatory arrest. The EEG had been seen to do the same in more than half of a larger series of children recorded at that stage. The results suggest that evoked potentials may be a sensitive indicator of early impairment of cerebral function and may demonstrate useful change sooner than the EEG. The examination may be useful in following children with illnesses producing hypoxia or anoxia. The N1 component was as easily and as frequently identifiable as the P2 component. Under the stress of this procedure, the latency of the P2 component became more variable than the N1 peak. The results suggest the N1 component may be as useful and perhaps more useful than the P2 wave in following the effect of some CNS stresses in children.

Cardiac Surgical Procedures↗
PubMedDate not supplied

Imaging of nodal metastases in the head and neck.

Therapeutic outcome of head and neck cancer is influenced strongly by the presence of nodal metastases. Sensitivity and specificity of the physical examination for the diagnosis of nodal metastasis is unsatisfactory, resulting in both false negatives and false positives of 25 to 40%. Preoperative detection of nodal metastases therefore becomes one of the important goals of imaging studies of patients with head and neck cancer. Despite several advanced techniques and the wide clinical use of MR, MR has surprisingly added little to the diagnostic accuracy of contrast-enhanced CT. Although CT and MR allow detection of abnormally enlarged nodes or necrotic nodes, neither borderline-sized nodes without necrosis nor extracapsular spread are reliably differentiated from reactive or normal nodes in patients with head and neck cancer. Lack of definitive diagnostic methods of metastatic lymph nodes is a serious shortcoming in the preoperative workup for patients with head and neck cancer. To avoid missing small metastatic nodes, a large number of patients clinically staged as N0 have undergone elective neck dissection to exclude metastases. With development of more tissue-specific imaging techniques, patients can be better characterized according to the status of nodal disease so that an appropriate therapeutic protocol can be designed for an individual case.

Adult↗
PubMedDate not supplied

Focal cerebral magnetic resonance changes associated with partial status epilepticus.

We report 2 patients with transient abnormalities on magnetic resonance imaging (MRI) associated with partial status epilepticus (SE). A man with a 4-month history of partial seizures had complex partial SE for 9 days, with left temporal maximum on ictal EEG. Left temporal lobe T2 signal was increased on MRI during SE, but cerebral MRI was normal 9 weeks later. A woman with "cryptogenic" temporal lobe epilepsy for 16 years had complex partial SE for 1 week, with right temporal maximum on ictal EEG. T2 Signal was increased over the entire right temporal lobe, extending into the insula, without mass effect, on MRI 1 month after SE ended. Repeat MRI 1 month later showed marked decrease in volume of increased T2 intensity, without gadolinium enhancement, but with mild mass effect over the right anterioinferomesial temporal areas. A gemistocytic astrocytoma was resected. Focal cerebral MRI abnormalities consistent with cerebral edema may be due to partial SE but also may indicate underlying glioma, even in long-standing partial epilepsy. Focal structural imaging changes consistent with neoplasm should be followed to full resolution after partial SE.

Adult↗
PubMedDate not supplied

Chronic acquired hepatic failure: MR imaging of the brain at 1.5 T.

The results of MR imaging of the brain at 1.5 T in 42 adults with non-Wilsonian chronic hepatic failure are reported. T1-weighted images demonstrated increased signal in the globus pallidus in 30 patients and in the putamen in 21, while T2-weighted images demonstrated no corresponding alteration in signal intensity. Symmetric low intensity in the central portion of the globus pallidus on spin-density and T2-weighted images in two patients correlated with regions of calcification on CT scans. Increased intensity on T1-weighted images also occurred in the mesencephalon surrounding the red nucleus (17/42) and in the quadrigeminal plate (4/42). Three patients demonstrated increased intensity in the pons on T2-weighted images unassociated with clinical brainstem dysfunction. Increased intensity on T1-weighted images was seen in the anterior pituitary in 28 of 35 patients. Alterations in signal intensity were not demonstrated in the cerebral cortex or cerebellum. MR findings did not correlate with laboratory indices of hepatic or thyroid function, with histologic liver diagnosis, or with neurologic status at the time of MR evaluation. Increased signal intensity in the basal ganglia, pituitary gland, and mesencephalon surrounding the red nuclei is characteristic of chronic hepatocellular dysfunction. Deposition of an as yet unidentified paramagnetic substance or altered intracellular water relaxation associated with the proliferation of astrocyte cytoplasmic organelles is postulated as the likely mechanism for this previously undescribed MR manifestation of chronic acquired hepatic failure.

Brain↗