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Biomedical subjects

T Gillespy

Publications and source records attributed to T Gillespy.

At least 37 records · Page 2Linked to original sources

Osteoporosis.

Osteoporosis, a condition of decreased bone tissue that increases the likelihood of fracture, places a significant burden on our society in terms of health cost and morbidity. The most common type of osteoporosis is involutional, and two subtypes are recognized: type 1 and type 2. Type 1, or postmenopausal, osteoporosis is most commonly seen in perimenopausal and postmenopausal women from ages 51 to 75. Estrogen deficiency is the most dominant factor in the pathogenesis of this disorder. Type 2, or aging related, osteoporosis is seen in elderly women and men aged 70 or more. Bone loss in this group is related to aging, estrogen deficiency, negative calcium balance, and a variety of environmental and genetic factors. The best approach to the management of osteoporosis is to develop a lifelong strategy that maximizes peak bone mass and minimizes aging-related and postmenopausal bone loss. Estrogen is the only medication approved for the prevention of bone loss that is in general use. Other strategies to prevent bone loss (and maximize peak bone mass) include adequate calcium intake, adequate exercise, and avoidance of excess alcohol, tobacco, and caffeine use.

Adult↗

Magnetic resonance imaging in patients with inflammatory arthritis of the knee.

Magnetic resonance imaging (MRI) permits visualization of anatomic structures not appreciated by conventional radiographic imaging and may quantify inflammatory disease and its progression with greater sensitivity than available techniques. We therefore compared MRI with clinical evaluation and with radiographic examination of 17 patients with inflammatory arthritis of the knee. We sought to determine anatomic integrity of bone, cartilage, menisci, and ligaments, and to quantify joint effusion and synovial proliferation. Patients studied had rheumatoid arthritis (10 patients), juvenile rheumatoid arthritis (4 patients), ankylosing spondylitis (1 patient), and monoarticular arthritis (2 patients). In all patients MRI revealed clinically important abnormalities not detected by physical or conventional radiographic exams. These included proliferative synovitis (13 patients), cartilage thinning (2 patients), cartilage erosion (8 patients), bone infarction (1 patient), meniscal injury (1 patient), and synovial invagination into bone (1 patient). Also MRI indicated inflammatory disease to be quantitatively greater than had been appreciated on clinical examination or routine X-ray studies--proliferative synovitis (12 patients), erosion (7 patients), effusion (8 patients), cartilage thinning (11 patients), and ligamentous/meniscal damage (1 patient). These findings led to reassessment of anatomic staging and influenced therapeutic decision for these patients. Thus MRI provides clinically important information about joint integrity and inflammatory disease, with a sensitivity and resolution considerably beyond conventional techniques.

Adult↗

Electronic imaging in a teaching hospital intensive care unit: evaluation of the clinical review system.

An intrahospital image-communication and display system was installed and is in continuous use. All images obtained in the medical intensive care unit (MICU) are digitized in the radiology department, then transmitted, stored and retrieved at the nurses' station in the MICU. This unit was easy to install, required minimal user training, and has been in continuous use for 1 year with negligible down time. The details of this system are provided in this report.

Computer Communication Networks↗

The effect of hypoparathyroidism on the aging skeleton.

Serum concentrations of parathyroid hormone are frequently increased in elderly subjects. How much this increase may contribute to the development of osteoporosis in such subjects is unknown. Long-standing hypoparathyroidism has been reported to be accompanied by an increase in skeletal density. In seven consecutive women, aged 40 to 83 years, with hypoparathyroidism of at least 18 years duration, the mineral density in the lumbar vertebrae was measured by quantitative computed tomography (QCT) and dual photon absorptiometry (DPA). In these subjects, the bone mineral density by dual photon absorptiometry was 1.4 to 6.2 standard deviations above mean values for age-matched normal women. However, the mineral density of vertebral trabecular bone as determined by quantitative computed tomography was only slightly increased above values reported for normal women. The differences between the values determined by dual photon absorptiometry and quantitative computed tomography indicate that most of the increase in mineral density was a reflection of increased cortical bone. Roentgenograms of the metacarpals did not reveal consistent differences between normals and the hypoparathyroid subjects. These findings suggest the possibility that control of parathyroid function might be of value in treating osteoporotic patients.

Absorptiometry, Photon↗

Hypertrophy of C-1 anterior arch: useful sign to distinguish os odontoideum from acute dens fracture.

Dens fractures are often difficult to detect radiographically because of overlapping structures. The lateral radiographs were examined of all patients at the authors' institution who demonstrated an abnormal odontoid process or an abnormal anterior arch of C-1. Six patients were found: Four had os odontoideum, one had rheumatoid arthritis, and one had a congenital defect in the posterior arch of C-1. All had hypertrophy of the C-1 anterior arch on the lateral view. The width of the anterior arch of C-1 and the cortical thickness of the anterior arch in these six patients were measured and compared with the findings in a control group of 20 patients; the measurements from the six patients were found to be significantly greater. Hypertrophy of the anterior arch of C-1 is a useful sign of a chronic pathologic condition at the atlantoaxial articulation, and in the setting of acute trauma it may be an important clue that prevents unnecessary invasive treatment for a mistaken diagnosis of fractured dens.

Acute Disease↗

Diagnostic imaging of pelvic and chest wall trauma.

Imaging of patients with pelvic trauma begins with a logical approach to plain radiographs. These films reveal the probable mechanism of injury and suggest a rationale for emergent reduction. Radiographs, along with the clinical impression, suggest the likelihood of associated soft tissue injury, possibly requiring further specific radiographic studies. Significant vascular injury most often accompanies disruption of the posterior pelvic ring. Bladder and urethral trauma may be suspected in any displaced type III pelvic fracture with suggestive clinical signs. Ideally, urethrography precedes bladder catheterization. Acetabular fractures must be recognized because of their implications for future hip joint function. CT is very helpful in definitive treatment planning of pelvic (especially acetabular) fractures but may be delayed until other life-threatening injuries have been addressed. Plain radiography is also well suited to evaluation of chest wall trauma. When multiple ribs are fractured in two places, the radiologist should suggest the possibility of flail chest. Sternal fractures and multiple rib fractures, including the first three ribs, may herald life-threatening vascular or cardiac damage. To summarize, the radiologist contributes most to the care of the trauma patient by recognizing roentgen patterns of injury, knowing which are commonly accompanied by damage to critical soft tissues, and performing the indicated radiographic studies efficiently.

Acetabulum↗

Direct coronal computed tomography arthrography of osteochondritis dissecans of the talus.

Although radiographs, arthrography, tomography, and computed tomography can all be used to diagnose osteochondritis dissecans of the talus, these imaging methods may not demonstrate whether an undisplaced osteochondral fragment has any attachment to the articular cartilage or bony bed of the talus. As lack of such attachment is a relative indication for surgery, we studied the feasibility of using coronal computed tomography (CT) after double contrast arthrography to demonstrate attachment in four patients with osteochondritis dissecans seen on radiographs. Direct coronal CT arthrographic images showed intact articular cartilage in three patients. In the fourth patient, overlying cartilage was virtually absent and contrast tracked beneath the fragment, an appearance that correlated with arthroscopic findings of partial articular cartilage attachment and no union at the osteochondral fracture line. Our initial experience suggests that direct coronal CT arthrography clearly shows the state of attachment of the osteochondritic fragment to the talus.

Air↗

Imaging of atypical lipomas of the extremities: report of three cases.

Atypical lipomas are soft tissue neoplasms which differ from simple lipomas in that they consist of mature fat cells interspersed with occasional areas containing a variable admixture of multinucleated cells, collagen bundles, and adipocytes with large, hyperchromic nuclei. Although these histopathologic features resemble those of liposarcoma, atypical lipomas occurring in the extremities differ from liposarcoma because they have no tendency for distant metastases. Three patients with atypical lipomas involving the posterior compartment of the thigh are presented. The lipomas were imaged with computed tomography (CT) and magnetic resonance imaging (MRI), using a 0.15-T whole body imager. Although all lesions appeared largely lipomatous, the three lesions simulated liposarcoma on both CT and MRI. On CT, each lesion demonstrated small areas of confluent soft tissue density; these areas were hyperintense with adipose tissue on strongly T2-weighted MRI. We conclude that atypical lipoma of the extremities may not be distinguishable from liposarcoma on imaging and that biopsy is necessary for differentiation.

Adult↗

Staging of intraosseous extent of osteosarcoma: correlation of preoperative CT and MR imaging with pathologic macroslides.

The accuracy of preoperative computed tomography (CT) and magnetic resonance (MR) imaging in the measurement of intraosseous tumor extent in 17 cases of osteosarcoma of an extremity was compared with macroslides of surgical specimens. Longitudinal intraosseous extension of tumor from the adjacent articular surface was measured on imaging studies and macroslides to the nearest millimeter. The average difference between macroslide and CT measurements (15 cases) was 16.5 mm +/- 10.7, and the average difference between macroslide and MR imaging measurements (17 cases) was 4.9 mm +/- 4.3. However, much of the latter difference appears to be caused by use of a different plane of section in MR imaging compared with that in macroslides, since in a subgroup of five specimens with an identical plane of section, the average difference was 1.8 mm +/- 1.6. The authors conclude that MR imaging is extremely accurate in the assessment of intraosseous extent of osteosarcoma.

Adolescent↗

Musculoskeletal tumors: T1 and T2 relaxation times.

The T1 and T2 relaxation times of primary tumors of the musculoskeletal system were calculated in 54 patients. No correlation was found between the relaxation values and the histopathologic type of the tumors. Lipoma had the same relaxation characteristics as normal fat. Otherwise tumors could be differentiated from normal tissue, but there was no significant difference between malignant and benign tumors, and the mean values for the different histopathologic types differed significantly only in a few instances. Hence T1 and T2 measurements are of limited value for histologic characterization of musculoskeletal tumors.

Bone Neoplasms↗

Dorsal fracture of the hamate: distinctive radiographic appearance.

Six patients who injured their wrists had radiographs documenting a dorsal, 5- to 10-mm oblong fragment of bone immediately proximal to the base of the fourth and/or fifth metacarpal bones. The fragment was seen on the pronation oblique and/or lateral projections, but not on the posteroanterior projection. The radiographic appearance of the fragment was remarkably similar in all cases. In the one patient in which it was performed, pluridirectional tomography demonstrated that the fragment originated from the dorsal surface of the hamate. Five of the six patients also had associated posterior dislocation of the fourth and/or fifth metacarpals. We conclude that this fragment represents a coronal fracture through the body of the hamate resulting from posterior dislocation or subluxation of the fourth and/or fifth metacarpal.

Adult↗

High resolution computed tomography of knee menisci.

Sixty four menisci in 22 patients were examined by non-contrast high resolution computed tomography (CT). Fifty four menisci were imaged on a GE 8800 CT scanner. The other 10 were imaged on a GE 9800 CT scanner. Nineteen menisci were shown to be torn on arthrography and/or arthroscopy--12 medially and 7 laterally. The remaining menisci were normal. When the meniscal CTs were reviewed collectively by three observers without knowledge of arthrographic or arthroscopic results, sensitivity was 63%, specificity was 93%, and accuracy was 84%. Although only 10 menisci were imaged on the GE 9800 scanner, the sensitivity in this subset of scans was 83%, the specificity 100%, and the accuracy was 90%. These results suggest that noncontrast CT cannot replace arthrography or arthroscopy, but it is possible that images obtained on the GE 9800 or comparable CT scanner may be accurate enough to be used for screening of meniscal tears in selected patients.

Adult↗

Primary musculoskeletal tumors: examination with MR imaging compared with conventional modalities.

In 176 cases of primary musculo-skeletal tumors, the informative value of magnetic resonance (MR) imaging was compared with that of plain radiographic examination, angiography, scintigraphy, and computed tomography (CT). In all patients the surgical and histopathologic results were known. For bone tumors confined to the bone, MR imaging was excellent for evaluation of intraosseous extent, but it could not be proved significantly better than CT or scintigraphy. MR imaging was inferior to plain radiography and CT for evaluation of calcification, ossification, cortical destruction, and endosteal/periosteal reaction. For soft-tissue tumors and bone tumors with soft-tissue extension, MR imaging was significantly better than the other modalities in all variables examined: delineation between tumor and muscle, tumor and vessel, tumor and fat, tumor and joint, and tumor and bone, as well as depicting intralesional necrosis and bleeding.

Adolescent↗

High-resolution CT of the wrist: initial experience with scaphoid disorders and surgical fusions.

We performed high-resolution CT scans on 30 wrists in 27 patients with either previous surgical intercarpal fusion or known or suspected scaphoid abnormalities. Most examinations used the same protocol: contiguous 1.5-mm axial sections parallel to the long axis of the body of the scaphoid, small reconstruction circle, and bone reconstruction algorithm. Fifteen patients were evaluated for union of previous surgical carpal fusions; eight patients were evaluated for healing of scaphoid fractures; and the other four patients had miscellaneous disorders, including a midcarpal dislocation with a scaphoid fracture. High-resolution CT clearly showed whether the carpal fusions were united. In addition, metallic fixation devices were easy to locate and did not significantly degrade image quality. Osseous union of healing scaphoid fractures was reliably assessed. We conclude that high-resolution CT of the wrist is a useful method for evaluating surgical carpal fusions and various disorders of the scaphoid.

Arthrodesis↗

Oblique head position in temporomandibular joint arthrography.

Thirteen patients were prospectively studied with arthrography to determine whether oblique head positions were helpful in diagnosing internal derangement of the temporomandibular joint (TMJ). After injection of contrast material, inclined transcranial lateral spot films were obtained with the patient's head in upward oblique, downward oblique, and neutral positions. The spot films were analyzed for internal derangement by assessing the size of the mass effect on the arthrogram. Twelve of the 13 arthrograms showed evidence of internal derangement of the TMJ. However, the apparent size of the mass effect varied in different head positions. Each of the three views failed to demonstrate the mass effect in at least one instance (eight different patients). No head position was better than another in demonstrating the mass effect. Thus, oblique head positions are useful adjuncts for diagnosing internal derangement of the TMJ.

Arthrography↗