Biomedical subjects
Publications and source records attributed to A M Wang.
A 31-year-old woman with an aneurysmal bone cyst of the L1 vertebral body proved by biopsy and studied by plain lumbar spine roentgenography, radionuclide studies, myelography, and CT is presented. The unusual location of involvement of the vertebral body alone and the difficulty in differential diagnosis between aneurysmal bone cyst and benign giant cell tumor are discussed.
Cervical spinal epidural hematoma is a rare cause of acute neurologic syndromes including paralysis of various types. Although devastating, it can be successfully treated surgically if recognized early. We report two cases of spontaneous cervical epidural hematoma diagnosed by computed tomography, the first with a plain scan and the second with a scan after intrathecal injection of metrizamide. In both patients the diagnosis was not clinically suspected. Surgery resulted in a dramatic improvement of the neurologic deficit in both cases.
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The simultaneous occurrence of two intracerebral hematomas in different arterial territories of the brain is rare. We report the clinical, radiologic, and post-mortem findings in two such cases. The absence of readily identifiable vascular disease in such patients suggests that a subtle degenerative process may be active in the pathogenesis of this condition.
Computed tomographic (CT) myelography, when used with metrizamide, permits a reliable demonstration of syringohydromyelic cavities in the cervical spinal cord. We report 6 cases of cervical syrinx demonstrated by high-resolution CT 4 h after metrizamide myelography; these cavities, which were not suspected clinically, extended into the thoracic cord. In addition 4 cases were associated with Chiari Type 1 malformation and 1 case was associated with both Chiari Type 1 malformation and infratentorial arachnoid cyst. We recommend that CT evaluation of cervical syringohydromyelia routinely include the thoracic spine, in order to demonstrate possible thoracic extension of the cavity. Scans of the foramen magnum are also recommended, because of the possibility of concomitant lesions, especially Chiari Type 1 malformation.
In order to better understand the nature of clinical teaching, 44 two-hour observations of instructors in clinical and field settings were conducted. The instructors were teaching clinical nursing courses from the sophomore through the senior level. The observers recorded the frequency of 16 techniques using a category system as well as data concerning the student-teacher ratio, type of class, and other information. The results show that one third of the interactions between student and faculty lasted one minute or less and one third lasted one to six minutes. Majority were initiated by the faculty member with a 1:1 ratio. Analysis of the types of techniques most frequently used across all courses were either leading/direct questions or information giving. Discussion and implication of the results of this study are discussed in light of the realities of clinical experiences for the baccalaureate nursing student; e.g., effects on problem-solving abilities of students; need to improve clinical teaching interaction skills; and curriculum change. This study describes the interaction techniques that nursing faculty used with students in clinical and field settings. Improving clinical teaching is currently a priority for nurse educators. Many people assume that they have a good idea of what transpires between faculty and students in clinical settings. Yet very little is actually documented on this topic. Before improvements can be made, we should have a more complete understanding of what is happening. This can best be accomplished by observing and documenting faculty interactions with students. Therefore, the need to obtain better information about faculty-student interactions in clinical and field settings was the impetus for this quantitative descriptive study.(ABSTRACT TRUNCATED AT 250 WORDS)
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A 47-year-old woman presented with a 6-month history of progressive dizzy spells and occasional impairment of vision. Cranial computerized tomographic (CT) scan showed a calcified mass in the atrium of the left lateral ventricle, densely enhanced after intravenous administration of contrast material. Left carotid and vertebral angiograms demonstrated that the feeders of the tumor were coming from the left anterior choroidal and left lateral posterior choroidal arteries, both of which showed dilatation and neovascularity. The CT and angiographic findings led to successful removal of the tumor without impairment of the patient's vision. The pathological diagnosis was meningioma.
Two cases of surgically proven myxopapillary ependymomas of filum terminale are reported. In both, myelography and metrizamide-enhanced computed tomographic (CT) scans were performed. An intramedullary tumor in the lower thoracic spine, soft-tissue masses in the neural foramina and enlarged bony spinal canal in the lower thoracic and upper lumbar spine were noted in one case and, in the other, an intradural extramedullary tumor at T12-L1 level. Both patients had normal cranial CT scans, and both presented with similar symptoms--low back pain and weakness and paresthesia of leg or legs for up to 3 years' duration. Myelography and metrizamide-enhanced CT scans were performed in order to evaluate disc disease in one patient and spinal stenosis in the other. Ependymoma was an incidental finding, which was then removed by surgical resection. Pathology confirmed the diagnosis.
Air embolism to the brain occurred several days after insertion of an intraaortic balloon pump. CT demonstrated diffuse hemispheric edema along with two small collections of air in the cerebral hemispheres. Early diagnosis of air embolism to the brain allows early institution of proper therapy in this life-threatening condition.
A case of intradural herniation of a thoracic (T12-L1) intervertebral disc is reported. On metrizamide myelography, this lesion resembled an intradural extramedullary tumor with an extradural component. A computed tomographic (CT) scan taken immediately after the myelogram, showed gas in the spinal canal and in the intervertebral disc. In addition, it showed a high-density mass located in the ventral epidural space and also intradurally. The density of this soft-tissue mass was identical to that of the intervertebral disc. CT provided very important information regarding the precise location and probable etiology of the lesion, and the success of surgery.
A 28-year-old male was found on CT metrizamide myelography to have an intradural extramedullary tumor at the T8-T9 level. This was seen to compress the spinal cord, and on surgery it was proven to be medulloblastoma. Cranial CT scans disclosed only mild hydrocephalus and minimal anterior displacement of the inferior fourth ventricle on the right. However, magnetic resonance imaging (MRI) which was performed after the spinal surgery demonstrated an inferior cerebellar vermian tumor.
Seven cases of surgically proven intraspinal synovial cysts are reported. Computed tomographic (CT) scans demonstrated a series of low-density masses adjacent to the facet joints; in three cases, a dense rim indicated a calcified wall on the cyst; in one, the wall was partially calcified; and in three the mass appeared to be filled with gas. In all of these cases, there was severe degenerative facet disease at the same level as the synovial cyst. In six patients, the cysts were unilateral, while one was bilateral; seven cysts were located at the level of L4-L5, and one at L3-L4. We conclude from this study that the intraspinal synovial cyst can be identified reliably by the CT scan.
A patient with surgical and neuropathologically confirmed subdural sarcoid granuloma was evaluated using angiography, contrast-enhanced CT and MR. MR images were obtained on a superconducting magnet with T1, intermediate and multi-echo T2 weighted sequences. Review of the 2 prior cases of subdural sarcoid granuloma from the literature evaluated with MR confirm the variable nature of signal intensities of the lesion. MR was most useful in anatomically evaluating the lesion and planning neurosurgical intervention but both CT and MR alone, in this case, did not definitely obviate the other differential diagnosis including meningioma en-plaque, lymphoma, or metastasis.
Osteogenesis imperfecta is a disease of bone formation subdivided into two types, congenita and tarda. It is associated with bony fragility, blue sclerae and abnormality of tooth dentin. Rarely the tarda form is associated with basilar invagination or infolding of the foramen magnum and upper cervical segments into the posterior fossa. This results in hydrocephalus and a spectrum of neurologic dysfunction known as the foramen magnum compression syndrome. Many radiologic methods have been used to evaluate basilar invagination including plain film and CT. We describe a patient with osteogenesis imperfecta tarda examined with CT, with a unique finding of diffuse cerebral atrophy associated with basilar invagination.
The brain magnetic resonance (MR) and computed tomography (CT) finding in a 37-year-old patient with a history of persistent headache and secondary hypogonadism and with a strongly positive blood and cerebrospinal fluid (CSF) fluorescent treponemal antibody-absorption (FTA-ABS) test is reported. A focal enhancing mass was demonstrated involving the tuber cinereum. The mass was markedly reduced after the completion of a course of intravenous administration of penicillin G treatment. This case is interesting because of its rare incidence and unique neuroradiological findings.
Congenital anomalies of the cervical spine occur relatively commonly. An interesting anomaly is congenital spondylolisthesis of the sixth cervical vertebra. We are presenting a case of this anomaly as imaged with plain radiography and computed tomography. We have also reviewed the previous literature and attempted to clarify distinctions between bilateral cervical spondylolysis with spondylolisthesis and other cervical spine lesions.
Lumbosacral pain is a significant complaint in approximately one-half of all pregnancies. In 15%, the pain can be disabling. Although the mechanical and positional stresses of pregnancy have been cited as the primary source of this discomfort, in approximately 1:10,000 cases a herniated lumbar disc (HNP) can be identified as the proximal cause of pain. A 35-yr-old G4AB3PO patient presenting at 10 wk of pregnancy with severe incapacitating lumbar radiculopathy is described. Magnetic resonance imaging, selected by the patient as a diagnostic option, demonstrated a clinically suspected large midline HNP at the L5-S1 level. In the past, visualizing the presence of a HNP during pregnancy by either computerized axial tomography scan or myelography has exposed the fetus to ionizing radiation. However, magnetic resonance imaging now permits a more detailed evaluation without similar x-ray exposure. To date, no recognized biologic effect of MRI on the developing fetus has been reported. Although the long-term effects of an magnetic resonance imaging on the developing fetus have not been conclusively evaluated, its potential for accurate diagnosis and subsequent patient management, as well as planning the delivery, appears to outweigh any recognized hazard to the developing fetus.