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Biomedical subjects

W A Carpenter

Publications and source records attributed to W A Carpenter.

9 recordsLinked to original sources
PubMed1996

Accuracy of direct signs of tears of the anterior cruciate ligament.

OBJECTIVE: To evaluate the accuracy of direct magnetic resonance imaging (MRI) signs of tears of the anterior cruciate ligament. PATIENTS AND METHODS: Over the period April 1991 to February 1994, 92 consecutive MRI studies of the knee were obtained for which arthroscopic data were also available. The MRI studies were retrospectively evaluated for course, continuity, signal intensity, morphologic features, contour and visualization of the anterior cruciate ligament. Arthroscopic findings were correlated with individual primary signs and the overall MRI diagnosis. RESULTS: Among the cases studied were 4 partial and 32 complete tears of the anterior cruciate ligament (as determined by arthroscopy). Because of the low number of partial tears, it was not possible to draw any meaningful conclusions about the MRI diagnosis of this type of tear. For complete tears, the criteria with the highest accuracy were abnormal course of the ligament (96.0%) and high signal intensity (89.3%). The overall diagnostic accuracy of MRI was 98.8%. CONCLUSIONS: The most accurate direct MRI finding in patients with a complete tear of the anterior cruciate ligament was abnormal course of the ligament, followed by abnormally high signal intensity.

Adolescent↗
PubMed1995

Renal osteodystrophy: imaging findings that mimic those of other diseases.

Musculoskeletal complications in patients with chronic renal failure are common and may be related to the disease itself or to treatment. The altered metabolism in patients with chronic renal failure leads to renal osteodystrophy, which consists of osteomalacia and secondary hyperparathyroidism [1]. Erosive changes attributable to secondary hyperparathyroidism may be easily confused with rheumatoid arthritis, seronegative spondyloarthropathies, infection, or even malignancy. Brown tumors and amyloid deposition can easily be mistaken for a neoplastic process. The purpose of this article is to illustrate radiographic findings that are caused by renal failure and that often mimic other diseases by use of plain radiographs, CT scans, and MR images. Particular emphasis is placed on periarticular findings.

Arthritis, Rheumatoid↗
PubMed1994

Color map of contrast enhancement on MR images: use of desktop computers.

An alternative method of presenting and evaluating unenhanced and contrast-enhanced MR images is illustrated. We used a desktop computer and commercially available software to combine unenhanced and contrast-enhanced images to produce a color map of contrast enhancement superimposed on a gray-scale image. The color-enhanced images increased the conspicuousness of the areas of contrast enhancement, which is particularly important if the enhancing structures are small or adjacent to fatty tissues. The process has advantages over standard subtraction techniques in that gray scale is preserved while areas of subtle contrast enhancement are readily seen as areas of color. Although applied to MR imaging, this method may also be applicable to other studies that use contrast enhancement.

Achilles Tendon↗
PubMed1978

Fluid dynamics in cerebral angiography.

Flow field characteristics are described so that the physician may have a better understanding of the mechanical effects of rapid intravascular injection of a highly ionized hypertonic solution. Theoretical and experimental results which illustrate the fluid dynamics involved are presented. This knowledge may be helpful in diminishing the overall complication rate in cerebral angiography and in outlining the carotid arterial complex, which is frequently the site of dense atheromatous plaque deposition.

Arteries↗
PubMedDate not supplied

The distal biceps tendon. Two potential mechanisms involved in its rupture: arterial supply and mechanical impingement.

The purpose of this anatomic study was to evaluate potential causes of rupture of the distal biceps tendon, to assess the dynamic relationship of the proximal radioulnar joint during pronation and supination, and to identify potential sites of impingement of the distal biceps tendon. For the anatomic study specimens were evaluated by light microscopy, multiplanar gross dissections, and Spalteholz vascular injection. For the radiographic study computed tomography was used to assess dynamic changes in the radioulnar space in pronation, neutral position, and supination. Three vascular zones were identified in the distal biceps tendon. Vascular contributions were consistently noted from the brachial artery proximally and from the posterior recurrent artery distally. A hypovascular zone averaging 2.14 cm was evident between the proximal and distal zones. On sectioning through the proximal radioulnar joint 85% of the space was occupied by the distal tendon in full pronation. In addition, computed tomography imaging revealed a 50% reduction in the radioulnar joint at the radial tuberosity from full supination to full pronation. Mechanical impingement on the biceps tendon during forearm rotation and hypovascularity within sections of the tendon may contribute to attritional ruptures of the distal biceps tendon.

Cadaver↗
PubMedDate not supplied

Meniscofemoral ligament simulating tear of the lateral meniscus: MR features.

The meniscofemoral ligament can simulate pathology on magnetic resonance images. It can be mistaken for a free osteochondral fragment on sagittal images. A less common pitfall is the simulation of a tear of the posterior horn of the lateral meniscus. A case demonstrating this meniscal pseudotear is presented.

Adolescent↗