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Biomedical subjects

A J Christoforidis

Publications and source records attributed to A J Christoforidis.

18 recordsLinked to original sources

Tumors of the osseous spine: staging with MR imaging versus CT.

Twelve patients with tumors involving the osseous spine were evaluated with magnetic resonance (MR) imaging and computed tomography (CT), six with and six without intrathecal injection of contrast material. MR imaging was found to be superior to CT without contrast material and equal to CT with contrast material in delineating the anatomic relationships of the tumors, including bone involvement, spinal canal invasion, paraspinal soft-tissue extension, and vascular involvement. Since MR imaging can provide most of the anatomic information necessary for treatment planning, intrathecal injection of contrast material can be avoided in most instances when evaluating tumor involvement of the osseous spine. However, CT without contrast medium was superior to MR imaging in showing critical cortical bone destruction and calcified tumor matrix.

Humans

Intestinal transit time is delayed by artificial sphincters after massive enterectomy in dogs.

Artificial sphincters were created in three groups of dogs after the resection of 87.5 percent of the intestine in each animal. Intestinal transit time was measured after 6 weeks by observing the passage of a radiopaque medium through the animals' intestinal tracts. No statistically significant differences were found between the intestinal transit times of dogs with one artificial sphincter and control animals. In dogs with two artificial sphincters there was a delay in the radiologically monitored intestinal transit time that was statistically significant compared with that of the control group.

Animals

Joint effusions: MR imaging.

Magnetic resonance (MR) images of the hips and knees of three healthy volunteers were reviewed and compared with images obtained from the hips of three patients with effusions. Comparison was also made with MR images obtained from two swine knees following the injections of saline in one and blood in the other. The anatomy of the knees and hips was well defined. The hip effusions were all easily recognized. MR images of the swine knees clearly demonstrated the experimentally produced joint effusions. The hip effusions and the experimentally introduced blood and saline all had long T1 and T2 values allowing easy differentiation from articular cartilage. We were unable to distinguish fresh blood from saline in the knee joints.

Adult

Meniscal tears: MR demonstration of experimentally produced injuries.

Magnetic resonance (MR) imaging was performed using a 1.5-T magnet on eight immature swine knees with surgically produced vertical and horizontal meniscal tears. Three radiologists, interpreting the images independently, detected all tears. Tears in the middle portion of the meniscus were best seen on sagittal views, while lesions of the anterior and posterior horns of the meniscus were best seen on coronal views. MR has several advantages over arthrography, the current diagnostic method for knee injuries: it is noninvasive, uses no ionizing radiation, and provides excellent soft-tissue contrast resolution.

Animals

The knee: surface-coil MR imaging at 1.5 T1.

Seven normal knees (in five volunteers) and seven injured knees (in seven patients) were examined by high-resolution magnetic resonance (MR) imaging at 1.5 T with a surface coil. Seven medial meniscal tears, three anterior cruciate ligament tears, one posterior cruciate ligament avulsion, an old osteochondral fracture, femoral condylar chondromalacia, and one case of semimembranous tendon reinsertion were identified. MR images correlated well with recent double-contrast arthrograms or results of surgery. All tears were identified in both the sagittal and coronal planes. Because of its ability to demonstrate small meniscal lesions and ligamentous injuries readily, MR imaging with a surface coil may eventually replace the more invasive arthrography.

Humans