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Biomedical subjects

H A Klein

Publications and source records attributed to H A Klein.

At least 37 records · Page 2Linked to original sources
PubMed1989

The scope of false-positive iodine-131 images for thyroid carcinoma.

Iodine-131 is used to detect and treat functioning lesions of papillary and follicular carcinoma of the thyroid. False-positive images although rare, do occur, with major categories being 1) body secretions, 2) pathologic transudates and inflammation, 3) nonspecific mediastinal uptake, and 4) neoplasms of nonthyroidal origin. The authors present eight cases that fall into the first three categories, including three types not previously reported--a lymphoepithelial cyst, a scrotal hydrocele, and a skin burn. The classification of mediastinal uptake as false positive is tentative. High-dose images and those exploiting therapeutic doses have an increased detection rate for both true and spurious lesions. Appropriate caution is advised in the interpretation of I-131 images.

Adolescent↗
PubMed1988

Simultaneous acquisition of physiological data and nuclear medicine images.

A technique has been developed that allows the simultaneous acquisition of both image and physiological data into a standard nuclear medicine computer system. The physiological data can be displayed along with the nuclear medicine images allowing temporal correlation between the two. This technique has been used to acquire images of gastroesophageal reflux simultaneously with the intraluminal esophageal pH. The resulting data are displayed either as a standard dynamic sequence with the physiological data appearing in a corner of the image or as condensed dynamic images.

Electronic Data Processing↗
PubMed1987

Normal variation in radionuclide esophageal transit studies.

We studied the esophageal transit of aqueous 99mTc-sulfur colloid in 16 normal subjects, 8 of them twice. Condensed dynamic images having a spatial and a temporal dimension fell into four patterns: (1) idealized form, (2) retrograde motion, (3) splitting of the bolus, and (4) generation of a substantial residual component. The retrograde index quantifying retrograde motion in the first swallow (RI), the rapid component mean transit time through the esophagus in the first swallow (MTT), and the residual fractions after the first, second, and fourth swallows [RF(1), RF(2), and RF(4)] were computed. The intrasubject and intersubject variation of the quantitative results suggest that normal subjects have sporadic aberrant swallows with high RI and/or RF(1). RF(2) and RF(4) showed a significant positive correlation with age.

Adult↗
PubMed1986

Applications of condensed dynamic images.

In appropriate cases, information from a dynamic series of nuclear images may be condensed into a single image with one spatial and one temporal dimension. A useful elaboration of the method consists of the masking out of undesired spatial regions. The versatility of such condensed dynamic images is illustrated by examples derived from gastroesophageal and pulmonary studies. Advantages of the method include obviating the need to examine and comprehend multiple images as well as enabling economical archiving of image data. Its diagnostic potential is particularly evident in esophageal transit and infant gastroesophageal reflux studies.

Adult↗
PubMed1986

Role of inflammation in the lung disease of systemic sclerosis: comparison with idiopathic pulmonary fibrosis.

Alveolar inflammation is thought to underlie the development of pulmonary fibrosis in several forms of diffuse lung disease including the connective tissue diseases. The relationship between inflammation and the clinical manifestations of systemic sclerosis (scleroderma), such as skin and lung involvement, is less clear. We therefore evaluated 14 never-smoking patients with systemic sclerosis with pulmonary involvement by bronchoalveolar lavage (BAL) and compared the results with those found in eight nonsmoking patients with idiopathic pulmonary fibrosis (IPF) and eight normal subjects. The patients with scleroderma also underwent gallium citrate Ga 67 scanning. We found that patients with scleroderma and pulmonary involvement have alveolitis that appears to wane with time. In addition, patients with systemic sclerosis have a cellular profile in lavage fluid that appears to differ from that of patients with IPF. Finally, we found a significant correlation between BAL cellular recovery and the single-breath carbon monoxide diffusing capacity in patients with systemic sclerosis but not in patients with IPF. We conclude that inflammation may play an important role in the pathogenesis of the pulmonary disease of scleroderma and that different mechanisms may lead to fibrosis in IPF and scleroderma.

Adult↗
PubMed1985

Aging and memory in skilled language performance.

The issue of irreversible decrements versus developmental plasticity with aging was explored for skilled language users. Fifteen English teachers (22 to 31 years of age) and 15 retired English teachers (50 to 83 years of age) were tested for language memory, using a 2 X 2 X 2 (Recall vs. Recognition X Meaningful vs. Nonmeaningful X Incidental vs. Intentional) design, and for overall grammar-skill memory, using speed and error measures. On the language-memory test, experimental variables (but not the age variable) were related to performance. On the grammar-skill test, the older subjects showed longer completion times but no decrements in accuracy. The results provided support for developmental plasticity in language memory and suggested an optimistic view of memory for skilled content areas.

Aged↗
PubMed1984

Vertebral hyperemia associated with bone marrow insult and recovery.

A 15-year-old boy with rhabdoid sarcoma received chemotherapy, which was followed by bone marrow depression, massive nosebleeds and, finally, hematologic recovery. On both hepatobiliary and renal scintigraphy, prominent vertebral activity was present in early images. Correlation with his clinical course suggests that the findings reflect hyperemia due to marrow insult and recovery. Radionuclide imaging to detect hyperemia may be a useful probe for drug effects on hematopoietic bone marrow.

Adolescent↗
PubMed1984

Occult purulent pericarditis detected by indium-111 leukocyte imaging.

Leukocyte imaging with indium-111 is a relatively new technique which, to this point in time, has been discussed almost exclusively in the radiologic literature. Although this procedure has been used mainly to detect intra-abdominal infection, the thorax is routinely imaged along with the abdomen, and therefore detection of cardiac disease may be feasible. This case report is of a young woman after liver transplantation who developed occult purulent pericarditis initially detected by a leukocyte scan with indium-111. This case demonstrates that striking pericardial uptake on a whole-body indium-111 leukocyte scan can occur with purulent pericarditis, and it reemphasizes how insidiously purulent pericarditis may present in an immunosuppressed patient.

Adult↗
PubMed1984

Computer analysis of radionuclide esophageal transit studies.

For detailed examination of the esophageal transit of a swallowed radioactive liquid bolus, three computer-based techniques have been developed: (a) analysis of time-activity curves with decomposition into rapid and residual components, yielding the mean transit time for the former and the residual fraction for the latter; (b) reduction of dynamic image sequences to single condensed images, facilitating subjective assessment; and (c) tracking of the centroid of radioactivity, permitting quantification of retrograde motion. Studies were performed on 12 normal subjects and on six patients with motility disorders. Elevated residual fractions were observed in all the patients, and an abnormal degree of retrograde motion in two. Two normal and two abnormal studies exemplify the variety of patterns observed in condensed images.

Adult↗
PubMed1981

The role of the lateral malleolus as a stabilizing factor of the ankle joint: preliminary report.

A preliminary report evaluating the role of the distal fibula as the lateral supporting structure of the ankle is presented. The study involved loading the knee of an above the knee amputation specimen and recording the resultant strains on the distal fibula. This was done with the ankle of the specimen in neutral, dorsiflexion, and eversion. Results show the susceptibility of the lateral fibula to compressive strains, with the greatest compression noted when the ankle is in eversion. Early findings also indicate that the fibula and lateral malleolus play an insignificant role in the weightbearing process in the lower limb.

Amputation, Surgical↗
PubMed1979

Radioxenon ventilation studies with disposable apparatus: technique and application.

Modification of commercially supplied disposable apparatus for radioxenon ventilation imaging solved several problems: occasional poor inhalation of the initial bolus of gas, awkward initiation of the wash-out phase, and building up of pressure against which the patient must exhale in the wash-out phase. Two cases illustrate results of ventilation and perfusion imaging in chronic obstructive pulmonary disease and pulmonary embolism. A third case illustrates results before and after bullectomy, including quantitative data analysis of the wash-out phase. Although long-range economy is possible with permanent equipment, the use of the modified disposable apparatus may be preferable in certain circumstances.

Adult↗
PubMed1977

Transformation of stimulus information from very short-term memory.

Observers were shown a simple stimulus pattern, a mask pattern, and a test pattern on each trial. Different types of test patterns were used to assess transformations of material from very short-term memory. The durations of the initial stimulus pattern and the mask pattern were also varied. Significant differences in average response data were found between types of test pattern over exposure durations; however, sensitivity measures showed minimal differences between types of test pattern. This suggested some distinctions between input processing and response selection in the paradigm. Selective feature analysis seems to be a characteristic of response selection.

Discrimination, Psychological↗