Biomedical subjects

D Thickman

Publications and source records attributed to D Thickman.

45 records · Page 3Linked to original sources

PubMed1984

Magnetic resonance imaging of postoperative patients with metallic implants.

Magnetic resonance imaging (MRI) examinations were reviewed in 10 postsurgical patients with metallic implants in the abdomen or pelvis. MRI scans in these patients were free of the streak artifacts commonly encountered in computed tomography. This represents a significant advantage in diagnostic imaging in postsurgical patients, and it suggests that MRI may be a valuable technique in the postoperative assessment of patients with extensive abdominal surgical clips or metallic prostheses.

Adolescent↗

PubMed1983

NMR imaging of the chest at 0.12 T: initial clinical experience with a resistive magnet.

The chests of 40 subjects were imaged with an experimental nuclear magnetic resonance (NMR) imager operating at a magnetic field of 0.12 T. There were six normal volunteers and 34 patients with abnormalities affecting different areas, including the chest wall, pleura, hila, mediastinum, and lung parenchyma, and including benign and malignant processes. In this initial clinical experience, NMR imaging provided useful information on the presence and extent of disease by its ability to distinguish different tissues and by the excellent demonstration of vascular structures.

Humans↗

PubMed1983

NMR imaging of the abdomen at 0.12 T: initial clinical experience with a resistive magnet.

Forty-five patients with a variety of abdominal abnormalities and five normal volunteers were imaged on a 0.12 T resistive nuclear magnetic resonance system. Scans were obtained with saturation-recovery technique and short repetition times. The images reflected both proton density and T1 information. A variety of neoplastic and nonneoplastic disease processes involving the abdomen were imaged. Results suggest that clinically useful images clearly may be obtained at 0.12 T. In addition, saturation-recovery imaging with short repetition rates can detect a wide range of abdominal abnormalities.

Abdomen↗

PubMed1982

Fibrodysplasia ossificans progressiva.

Three hundred fifty-three previously reported cases of fibrodysplasia ossificans progressiva were reviewed and six new cases were analyzed radiologically. Characteristic findings of fibrodysplasia ossificans progressiva were confirmed and radiographic signs of the disease were demonstrated, including medial cortical thickening of the proximal tibia, narrow lumbar spinal canal, accessory epiphysis of the second phalanx of the fifth finger, and decreased humeral/epicondylar angle.

Bone and Bones↗

PubMedDate not supplied

Liver volume assessment by conventional vs. helical CT.

BACKGROUND: Accurate noninvasive measurement of the volume of the liver has many potential clinical applications and is an important element in the preoperative evaluation of the liver transplant recipient. Helical (or spiral) computed tomography (CT) has theoretical advantages over conventional CT in this application because the entire liver can be imaged in a single breath-hold, limiting inaccuracies related to patient motion and respiratory variation. METHODS: We compared liver volumes measured by conventional CT and helical CT in 22 patients undergoing preoperative evaluation for liver transplantation. RESULTS: The mean volume for helical CT is 1328 ml (SD 405) and conventional CT is 1323 ml (SD 417). CONCLUSIONS: We found no significant difference between the helical CT and conventional CT volumes for each patient.

Female↗

PubMedDate not supplied

Computed tomographic evaluation of the solitary nonpulmonic nodule.

CT has demonstrated its usefulness in the evaluation of the known solitary pulmonic nodule, however its application to the solitary nonpulmonic nodule has not been emphasized. Three cases illustrate the applicability of CT in localization of a nodule. The importance of obtaining bone windows in these cases is stressed. When comparison plain films and routine techniques are unsatisfactory, CT is valuable in providing a noninvasive means of diagnosis and patient reassurance.

Adult↗

PubMedDate not supplied

Nodule detection with and without a chest image.

The detectability of nodules displayed on uniform backgrounds was compared with their detectability on chest images by using receiver operating characteristic (ROC) curves. The images were displayed using a digital television system. Two conditions, chest image and uniform background, were compared at three different levels of added random noise. The viewing conditions were made as similar as possible by setting the luminance of the uniform background equal to the luminance of the lung in the chest image. Nodule detectability was significantly lower for the chest image than for the uniform background at each level of added random noise. The anatomic structure of the chest image interferes with the structural integrity of the nodule image resulting in lower detection performance.

Humans↗

PubMedDate not supplied

CT of melanoma liver metastases: is the examination without contrast media superfluous?

The current method of evaluating hypervascular liver metastases with CT includes both contrast enhanced and unenhanced studies. The necessity of performing both examinations for the detection of liver metastases in the workup of malignant melanoma has not been specifically addressed. This study evaluates potential additional information derived from an unenhanced examination of the liver. We studied 55 patients with malignant melanoma who had both contrast enhanced and unenhanced CT examinations performed during the workup and staging of their disease. Sixteen patients had 89 measurable liver lesions seen on enhanced CT. Three patients had liver lesions that were too numerous to accurately measure. Unenhanced CT demonstrated only 62% of the measurable lesions. All liver lesions seen on the unenhanced images were identified on the enhanced studies. Only one metastasis was found to be comparatively smaller on the enhanced examinations. The unenhanced examinations detected no additional lesions. It is reasonable to perform only an enhanced examination during the workup and staging of malignant melanoma liver metastases.

Adult↗

PubMedDate not supplied

Diagnosis of pneumoperitoneum: abdominal CT vs. upright chest film.

To compare the sensitivity of CT with upright chest radiography for the detection of free intraperitoneal air, we compared the results of these examinations performed on trauma patients who had introduction of intraperitoneal air from diagnostic peritoneal lavage (DPL). Thirteen patients were studied by abdominal CT within 24 h after DPL. Upright chest radiography was performed prior to abdominal CT or less than 4 h after abdominal CT. All patients demonstrated free air on abdominal CT. Only 5 of 13 (38%) patients demonstrated free air on plain radiography. The amount of free air demonstrated on CT was quantified into three groups. Upright chest radiography in the minimal group (less than three 1 mm pockets of air) was totally insensitive (0 of 2) in detecting free air. Upright chest radiography in the moderate group (greater than three 1 mm pockets, but less than 13 mm diameter collection of air) was 33% sensitive (3 of 9). Upright chest radiography in the large group (greater than 13 mm collection of air) was 100% sensitive (2 of 2). Abdominal CT is clearly superior to upright chest radiography in demonstrating free intraperitoneal air in this clinical setting.

Adult↗