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Biomedical subjects

R J Telepak

Publications and source records attributed to R J Telepak.

At least 19 recordsLinked to original sources
PubMed1999

Xenon spill distribution and room clearance.

The purpose of these studies was to investigate actual xenon gas clearance times under different exhaust conditions, to compare them with the calculated clearance times, to observe the distribution of the xenon gas while it was being exhausted from the room, and to determine the cause of a stationary xenon cloud that appeared on some clinical images. Clearance times with and without a flexible exhaust hose placed next to a simulated 133Xe gas spill were compared with clearance times measured in a room with all exhaust closed off. Two gamma cameras were used to observe the transport and exhaust of xenon following a simulated spill. Clearance times with the flexible exhaust hose were less than one minute because the xenon gas was removed before it had a chance to disperse into the room. Conventional room clearance calculations based on uniform mixing and measured exhaust rates yielded a clearance time of 22 min. The source of an artifactual stationary cloud image was discovered to be a small amount of xenon trapped between the collimator and camera face. A negative pressure and dedicated exhaust can be even more effective in exhausting spilled xenon from a room than air transfer calculations predict. The authors believe the flexible hose should always be used.

Air Pollution, Radioactive↗
PubMed1998

192IrCl acid skin burn: case report and review of the literature.

A worker was contaminated following a chemical explosion that splashed an HNO3 radioactive solution containing approximately 180 MBq (5 mCi) 192Ir onto the left side of his face. Initial efforts reduced the contamination at least fivefold. Removal of a patch of contaminated hair was necessary. Most of the contamination was fixed to the skin; only a small amount of contamination was absorbed.

Acids↗
PubMed1998

Thyroid palpation versus high-resolution thyroid ultrasonography in the detection of nodules.

Detection of thyroid nodules by physical examination and high-resolution ultrasonography was compared using small groups of blinded, experienced physician examiners working with a sample of 2441 persons from Estonia, most of whom were Chernobyl nuclear reactor clean-up workers. A random subsample of 113 (5%) persons was subjected to triple control examinations with both physical examination and high-resolution ultrasonography. Positive high-resolution ultrasonographic findings were considerably more reproducible among different observers than were positive physical examination findings. Agreement between methods was poor. Nodules were found in 169 (6.9%) subjects by physical examination and in 249 (10.2%) subjects by high-resolution ultrasonography. Physical examination found only 53 (21%) of the 249 nodules found by high-resolution ultrasonography. High-resolution ultrasonography did not confirm the existence of 115 (68%) of the 169 nodules found by physical examination. Only 6.4% of nodules less than 0.5 cm in diameter, as based on high-resolution ultrasonographic results, were detected by physical examination. Physical examination detection improved with increasing nodule size but was still only 48.2% for nodules larger than 2 cm. Physical examination was relatively effective in detecting nodules in the isthmus of the thyroid gland but much less so for nodules in the upper pole of the gland. Clinical evaluation and epidemiologic studies of nodular thyroid disease stand to benefit from the greater sensitivity and specificity of ultrasonographic examinations.

Adolescent↗
PubMed1995

Fourier phase analysis of first-pass data: noninvasive detection of pulmonary sequestration.

Nuclear medicine Fourier phase analysis of first-pass data was used to evaluate blood flow to cystic lung masses in two children suspected of having pulmonary sequestrations. In both cases, the Fourier images provided a rapid, noninvasive, inexpensive analysis of the blood supply to the masses and permitted identification of the masses as pulmonary sequestrations. The analysis does not depend on the location of the mass and demonstrates the location of systemic rather than pulmonic arterial blood supply to the mass. In one case, Fourier analysis identified a second source of systemic blood supply not visible with other imaging modalities. Preoperative assessment of a cystic lung mass using Fourier analysis enables noninvasive classification of the mass as a pulmonary sequestration with systemic blood supply and aids the surgeon in resection.

Bronchopulmonary Sequestration↗
PubMed1994

Hantavirus pulmonary syndrome: radiographic findings in 16 patients.

PURPOSE: To characterize chest radiographic features of Hantavirus pulmonary syndrome. MATERIALS AND METHODS: Initial and follow-up chest radiographs from 16 patients with confirmed Hantavirus pulmonary syndrome were reviewed for radiographic findings of either cardiogenic pulmonary edema or pulmonary edema due to increased permeability of the alveolar capillary membranes. RESULTS: Findings indicative of interstitial edema were present more frequently (14 [88%] of 16 patients) than is typically seen in adult respiratory distress syndrome (5%). Alveolar flooding subsequently developed in 11 (69%) of 16 patients and was not the peripheral pattern usually seen in the acute phase of adult respiratory distress syndrome. Overall mortality was 43%. Lung specimens obtained at autopsy showed a pattern of endothelial leak with minimal epithelial injury. CONCLUSION: The lung disease caused by Hantavirus in these patients may explain the findings of interstitial edema and central alveolar filling atypical of adult respiratory distress syndrome. Recognition of the radiographic pattern will be important in identifying this apparently widespread cause of increased permeability pulmonary edema.

Acute Disease↗
PubMed1993

Detection of hypervascular brown tumors on three-phase bone scan.

A patient with hyperparathyroidism secondary to chronic renal failure had multiple bony lesions with increased activity on both immediate static as well as delayed scintiphotos. One lesion in the distal femur was also exceptionally hot on the flow phase. Plain radiographs demonstrated lytic lesions with sclerotic margins and a narrow zone of transition. Open biopsy revealed histology consistent with brown tumor (osteoclastoma).

Acetabulum↗
PubMed1991

Preliminary assessment of computed tomography and satellite teleradiology from Operation Desert Storm.

Computed tomography at military transportable hospitals was used for the first time during the recent Operation Desert Storm in the Saudi Arabian desert. Scan quality was excellent and the scans proved clinically important in patient management. A teleradiology link via satellite to the U.S. mainland was also successfully employed. The objectives of the teleradiology link were to validate the concept distant interpretation of images obtained on the battlefield and to provide specialty radiology consultation. This technology shows great promise for future applications, both for combat casualty care and for civilian disaster medical support operations.

Hospitals, Military↗
PubMed1988

Effects of inversion on cardiovascular function: the bat scan.

This study was performed to measure the effect on cardiovascular functional parameters of remaining in an inverted position for a relatively short period of time. With the aid of radionuclide gated bloodpool scanning techniques, left ventricular ejection fraction (LVEF), heart rate (HR), systolic blood pressure (SBP), systolic average rate of left ventricular emptying (dV/dt), and double product (DP) measurement values were obtained from 16 normal, healthy subjects in four positions: supine, standing, half-inverted, and fully inverted. When comparing full-inversion to supine values, the HR and double product were not significantly different, the SBP was significantly higher, and the LVEF and dV/dt values were significantly lower. There were no significant differences between the partial and fully inverted positions. Comparison of standing to fully inverted positions reveals no significant change in SBP or double product. HR, LVEF, and dV/dt values were significantly lower in inverted subjects. It is suggested that these findings reflect the mechanism by which the cardiovascular system compensates for increased ventricular end-diastolic volume. Suggestions for future investigations include inverted cardiac ultrasound and right ventricular function studies.

Adult↗
PubMed1985

Gallium-67 scintigraphy in well-differentiated lymphocytic lymphoma of the skin.

Skin lymphomas are now divided into "T" or thymic cell lymphomas (mycosis fungoides being the principal type) and "B" cell lymphomas after the bursa of Fabricius. The "T" cell lymphomas all are identified by the thymic or cerebriform cell. Those lymphomas of the skin which do not contain these characteristic cells are derived from the bursa cells and are termed "B" cell lymphomas. A large percentage of these non "T" cell lymphomas have been histologically diagnosed as lymphocytic lymphoma of the skin (1). The authors had an opportunity to scan a patient with histologically proven lymphocytic lymphoma of the skin with Ga-67 and obtained on excellent correlation between gallium accumulation in the skin lesions and histologic confirmation of lymphocytic lymphoma.

Gallium Radioisotopes↗
PubMed1984

Tuboovarian abscess simulating giant colonic diverticulum.

The plain abdominal film finding of a large air-filled cavity has a differential diagnosis that includes giant colonic diverticulum, volvulus, giant Meckel's or other small-bowel diverticulum, emphysematous cystitis, vesicoenteric fistula, bowel duplication, and mesenteric cyst. The case presented here expands this differential diagnosis to include tuboovarian abscess with fistulous communication to the bowel.

Abscess↗
PubMed1984

Chest radionuclide angiography in the evaluation of pulmonary masses.

A retrospective analysis of 104 chest radionuclide angiography (CRNA) studies establishes the utility of this procedure in the evaluation of pulmonary malignancies and benign masses. Remarkable abnormalities in the perfusion of the lungs were identified in 36 (58%) of 62 cases that were not predictably normal or predictably abnormal form the clinical setting. While 60 of these 62 cases involved malignancy being evaluated for metastases, only 21 (34%) had metastases identified by radionuclide bone or liver-spleen scintigraphy. In addition to diagnosis of superior vena cava obstruction, the CRNA may have a more frequent application as an adjunct to routine scintigraphic studies directed to the identification of metastatic disease.

Adenocarcinoma↗
PubMed1983

Another use for the seven-pinhole collimator. Routine nontomographic imaging of the thyroid.

Relatively few seven-pinhole collimator systems purchased within the last three years are still in routine use. This paper describes a nontomographic use of the collimator for thyroid scanning. One image is obtained which simultaneously shows seven different projections of the thyroid gland. The diagnosis of thyroid abnormalities can frequently be made from this single composite image without the requirement for additional images. Further information can be obtained when needed by computer processing the image into tomographic slices.

Female↗