PubMed Health⌕ Search

Biomedical subjects

T J Greenan

Publications and source records attributed to T J Greenan.

6 recordsLinked to original sources
PubMed1993

Diagnostic imaging of sports-related spinal disorders.

Diagnostic imaging is a dynamic field that has taken a quantum leap over the past several years with the advent of MRI. Accordingly, it is integral that the sports medicine clinician be well acquainted with the sundry imaging modalities at his or her disposal, and be able to choose the appropriate study or studies that will provide the most useful and accurate information. Conventional radiography should be the first study performed in every athlete with sports-related injury to the spine. If radiography reveals evidence of spondylolysis with or without spondylolisthesis, MRI would be an extremely helpful adjunct for evaluation of the disc spaces, nerve roots, and neural foramina. Osseous fragments in the vicinity of the pars defect are well seen on CT but not MRI. These fragments can migrate and become symptomatic. Therefore, in the work-up of this subset of patients, CT does offer important supplementary data to the MRI. When conventional radiographs of the cervical spine corrected for magnification render the diagnosis of congenital cervical spinal stenosis, MRI should invariably be the next procedure of choice for evaluation of the spinal cord and to assess the functional reserve of the spinal canal. MRI is also the modality of choice now for evaluation of the athlete with degenerative disc disease and for the identification of degenerative disc disease associated with lumbar Scheuermann's disease. In the athlete with an acute cervical spine injury, following conventional radiography, the patient should be evaluated with CT to better characterize and define the extent of the fracture and to search for additional fractures. MRI should be performed in these patients after CT as it provides extremely valuable information regarding the status of the spinal cord. MRI because of its unparalleled soft-tissue contrast, noninvasive nature, ability to image in three orthogonal planes, and myelographic effect with certain pulses sequences has become the ideal imaging modality for spinal disease, and sports-related spinal disorders are certainly no exception.

Athletic Injuries↗
PubMed1992

Cerebral vasculitis: MR imaging and angiographic correlation.

Cerebral vasculitis is an unusual disorder with numerous causes. One such entity, noninfectious granulomatous angiitis of the nervous system (GANS), is an extremely rare disease with a predilection for leptomeningeal and parenchymal arteries and veins. Isolated involvement of the central nervous system is characteristic of GANS, which has also been referred to as primary angiitis of the central nervous system (PACNS). The results of magnetic resonance (MR) imaging and angiography in seven patients with presumed PACNS were retrospectively analyzed and correlated. MR images were positive in every case. Characteristically, lesions were multiple, bilateral, and supratentorial. Both gray- and white-matter infarcts were identified in four of seven patients; infarcts were most common in the deep white matter. PACNS can also appear as primary parenchymal hemorrhage or simulate low-grade glioma. All lesions identified on MR images were associated with positive angiographic findings of cerebral vasculitis in the corresponding vascular distribution. However, for 12 of 33 vascular distributions with angiographic evidence of cerebral vasculitis, no lesions were identified on MR images. These correlative observations suggest that some patients with proved PACNS may have normal MR imaging results.

Adult↗
PubMed1986

Do thalamic regions which project to rostral primate motor cortex receive spinothalamic input?

The purpose of this study was to examine whether spinal pathways terminate in regions of the primate thalamus which project directly to the motor cortex. In order to examine this issue we employed a 'double labeling' procedure which utilized transport of both anterograde and retrograde tracers in the same macaque. One tracer substance was injected into the cervical spinal cord and the other was injected into the rostral zone of primary motor cortex. We observed no overlap of spinothalamic terminations and thalamic regions which project to the motor cortex. Thus, our results provide no anatomical support for a direct thalamic relay of peripheral afferent input to the motor cortex of primates.

Afferent Pathways↗