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Biomedical subjects

D Magid

Publications and source records attributed to D Magid.

At least 91 records · Page 5Linked to original sources
PubMed1985

Femoral head avascular necrosis: CT assessment with multiplanar reconstruction.

Thirty-two patients with avascular necrosis (AVN) of the femoral head underwent imaging studies using computed tomography with multiplanar reconstructions (CT/MPR). Staging of the disease by means of CT/MPR images was compared with traditional staging by means of routine frontal and frog-leg lateral radiographs. CT/MPR examination upgraded staging in 30% of the hips studied and made significant contributions to patient management in 14 (54%) of 26 patients for whom both CT scans and plain-film radiographs were available for comparison. Asymptomatic and radiographically normal contralateral hips were found at CT study to have stage II or stage III AVN in four patients. Subtle alterations in trabecular patterns, joint spaces, femoral-head contours, and acetabula were well defined on CT/MPR studies in many cases; previously undetected or ill-defined abnormalities were frequently visualized. The major weight-bearing components of the hip (anterior and posterior acetabular columns, acetabular dome, and superior pole of the femur), which may be poorly defined on CT scans due to partial volume effects on the transaxial images, were best seen on the sagittal and coronal reconstructions. A new system for staging AVN is suggested.

Adolescent↗
PubMed1984

Desmoid tumors in Gardner syndrome: use of computed tomography.

Desmoid tumors are known to be associated with Gardner syndrome and, when located in the mesentery, can contribute to morbidity and mortality. Computed tomography (CT) was used to evaluate six patients with Gardner syndrome who, after colectomy, complained either of abdominal pain or of palpable masses. In five patients, desmoids of the mesentery, abdominal wall, and paraspinous muscles were diagnosed; four of these were later proven surgically. The sixth case, with both CT and subsequent surgery negative for desmoid lesions, is included to illustrate the ability of CT to replace exploratory surgery in certain instances. CT provides a relatively noninvasive means of assessing and following patients with Gardner syndrome after colectomy and delaying or preventing further surgery or, if necessary, providing a surgical "road map" to optimize unavoidable procedures.

Adult↗
PubMed1984

Computed tomography of the spleen and liver in sickle cell disease.

The spleen was assessed in 10 patients with sickle cell disease studied with computed tomography (CT) for abdominal pain and/or unexplained fever. Patients with homozygous sickle cell anemia were found to have small, densely calcified spleens with occasional low-density infarcts. Five of six had hepatomegaly, and there was one case each of hepatic abscess, infarcts, and hemochromatosis. All patients with heterozygous sickle cell disease were found to have splenomegaly, with a variety of findings including acute hemorrhage, acute and chronic infarcts, rupture, and possible sequestration. It was concluded that CT is useful for evaluating the status of the spleen and liver in symptomatic patients with sickle cell disease.

Adolescent↗
PubMed1983

CT evaluation of therapeutic embolization of hepatic hemangiomas.

Computed tomography (CT) was used to monitor the response to therapeutic embolization in two cases of giant cavernous hemangiomas of the liver. Base-line tumor volume and rat of enhancement were calculated. Therapeutic embolization with a detachable balloon or Ivalon microsphere plus a detachable balloon was then performed. CT was repeated to evaluate both change in tumor volume and in rate of enhancement ("fill-in") of the lesion. It was possible to document the response to embolization by changes in the size and the degree of enhancement of the lesions. Thus, CT can be used to document the success or failure of embolization of hepatic hemangiomas.

Adult↗
PubMedDate not supplied

Cervical fracture in ankylosing spondylitis: value of multidimensional imaging.

Ankylosing spondylitis creates a rigid spinal column that cannot easily accommodate to altered or increased forces. Fractures or fracture-subluxation may be seen following apparently trivial injury. Assessment of the lower cervical and cervicothoracic spine can be limited in the kyphotic, ankylosed spine. However, reformatted computed tomography (CT) data can be manipulated to provide true orthogonal (sagittal, coronal) planar images of the obliqued spine, and can be used to provide a three-dimensional overview of anatomy prior to treatment. One such case is presented.

Aged↗
PubMedDate not supplied

External jugular vein thrombosis: CT demonstration.

A case of external jugular venous thrombosis secondary to misplacement of central venous catheter is presented. The CT findings included enlargement of the external jugular vein, central thrombosis, and vessel wall enhancement. Computed tomography is an excellent noninvasive modality for the evaluation of suspected venous thrombosis.

Adult↗
PubMedDate not supplied

Computed tomography of stress fractures.

Three cases of stress fractures of the lower extremities are presented with corresponding CT. Findings of increased medullary cavity density, endosteal sclerosis, callus formation, and soft tissue swelling are demonstrated even though they are thought to be nonspecific in differentiating stress fracture from infectious or neoplastic processes. Only when actual failure lines are demonstrated by CT can stress-related injury be specifically suggested.

Child↗
PubMedDate not supplied

Multiplanar computed tomography of acetabular fractures.

Following plain radiographic examination CT with multiplanar reformatting (CT/MPR) was used to assess 34 patients with pelvic trauma and definite (24 patients) or clinically suspected (10 patients) fractures. Computed tomography/MPR detected four fractures missed on conventional radiography. The findings on CT/MPR led to major alterations of patient management in seven cases. In four patients in whom the initial decision had been to use closed management with traction, information derived from CT/MPR led to open surgical reduction. In three patients in whom the initial impression had been that open management was dictated, CT/MPR contributed anatomical information that reserved that decision, leading to more conservative management. In all patients going to surgery the surgeons believed that surgical planning and execution had been significantly affected by the information provided by CT/MPR. Computed tomography/MPR was used postoperatively in 10 patients to confirm the status of reduction and fixation and to evaluate patients with unusual problems in the recovery period.

Accidents, Traffic↗
PubMedDate not supplied

Design of custom hip stem prostheses using three-dimensional CT modeling.

Long life expectancy, demand for high activity levels, and bone loss at the time of revision motivate the search for reliable and successful noncemented hip stem designs. It is hypothesized that improved implant fit may increase the longevity of noncemented total joints. Quantitative X-ray CT has enabled the use of a computerized stem design program, which designs an optimal-fit hip stem for individual femurs. Computed tomography and interactive image processing methods are used to generate the individual three-dimensional femoral models, which are used by the stem design program. Optimal-fit design provides maximum stem-bone contact while satisfying the requirement of being surgically insertable. Previous methods of custom implant design, including those that use three-dimensional CT modeling, have not provided optimal stem-bone fit. Quantitative results of this new process are presented.

Aged↗
PubMedDate not supplied

CT detection of sacral osteomyelitis associated with pelvic abscesses.

In three patients the diagnosis of sacral osteomyelitis was made when CT demonstrated intraosseous (two) and intraforaminal (one) gas. Two of the three patients also had radionuclide bone scans, one of which was unremarkable. In the other case, radionuclide scintigraphy greatly underestimated the extent of the disease process when compared with CT. All three patients had contiguous pelvic abscesses as a cause of the osteomyelitis. Although there was a high clinical suspicion for an intraabdominal process, the diagnosis of superimposed osteomyelitis of the sacrum was unsuspected. The detection of intraosseous gas is a pathognomonic, albeit uncommon, manifestation of osteomyelitis. Although the radionuclide bone scan is the method of choice for detecting osteomyelitis, CT should be used as a complementary study in certain patients.

Abscess↗
PubMedDate not supplied

Musculoskeletal desmoid tumors: CT assessment during therapy.

Musculoskeletal desmoid tumors can be difficult to characterize and to follow. The rate of regression after radiotherapy is variable, with poor response to chemotherapy and postoperative recurrence being common. Eighteen patients undergoing therapy for proven musculoskeletal desmoid tumors had 52 CT studies, which were assessed to determine the utility of CT in following such patients. Computed tomography was found to offer excellent initial baselines prior to additional treatment and in the early postoperative period and followed the tumor response to treatment. Ultimate tumor response could not be predicted by characteristics of or change in tumor margins, by initial or subsequent tumor CT attenuation, by appearance following intravenous contrast medium, or by tumor location. Decreasing size and stabilization of size in a previously growing lesion were the only reliable signs of response; markedly increasing attenuation heterogeneity suggested but was unreliable as an isolated sign of response.

Adolescent↗
PubMedDate not supplied

Evaluation of CT techniques for reducing artifacts in the presence of metallic orthopedic implants.

Metallic intramedullary orthopedic implants generate artifacts that can markedly degrade transaxial CT images. The artifacts, typically seen as starburst streaking, result primarily from reconstructions involving missing projection data. Two approaches are clinically available to reduce the artifacts around orthopedic implants. These are (a) the imaging of implants with lower attenuation coefficients or smaller path lengths (less attenuating objects) and (b) the planar reformatting of image data. The sizing accuracy of these two approaches was quantified using phantoms and the efficacy using cadaveric femoral specimens. Results demonstrated that metal artifacts may be reduced and accurate bony dimensional data obtained.

Evaluation Studies as Topic↗