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Biomedical subjects

B E Oppenheim

Publications and source records attributed to B E Oppenheim.

18 recordsLinked to original sources

Direct comparison of fluorine-18-FDG SPECT, fluorine-18-FDG PET and rest thallium-201 SPECT for detection of myocardial viability.

UNLABELLED: Twenty consecutive patients were evaluated for presumptive myocardial viability using rest TI-SPECT, FDG-PET and FDG-SPECT. The FDG studies were performed after rest TI-SPECT to guide intervention or medical management. METHODS: Twenty patients with proven coronary artery disease, either known or suspected to have previous myocardial infarction and persistent perfusion defects shown by rest reinjection TI-SPECT, underwent FDG-PET and subsequent FDG-SPECT with a three-detector SPECT camera. FDG-PET and SPECT images were compared by five observers to determine if any fixed thallium segments were visualized by either FDG imaging method. RESULTS: Thirteen of 60 fixed segments were shown probably viable by FDG-SPECT (8 of 20 patients) and 14 of 60 by FDG PET (7 of 20 patients). Two patients had fixed thallium segments found probably viable with FDG by SPECT alone and one by PET alone. CONCLUSION: FDG is shown to provide additional information about myocardial viability. Both SPECT, using a three-detector camera, and PET with a specialized instrument are equally effective for imaging FDG in this application.

Coronary Disease

Computer-assisted radiology resident rotation scheduling.

The author developed a method for computer-assisted scheduling of resident rotations in which the chief resident determines the most desirable set of rotations for each resident, disregarding specific month assignments except as required or requested, and the computer generates the schedule by assigning months to rotations. The computer uses an efficient search algorithm to find a schedule that satisfies all requirements. The method satisfies training goals, staffing needs, and residents' desires more effectively than manual scheduling. Although fixed staffing levels for every rotation are required, flexibility is achieved through "dummy" assignments of rotations to residents.

Internship and Residency

Dynamic hepatobiliary SPECT: a method for tomography of a changing radioactivity distribution.

Dynamic single photon emission computed tomography (SPECT) of a changing radioactivity distribution can be performed with a rotating scintillation camera by acquiring several 360 degree studies and generating a new 360 degree study for which the acquisition time for every image is shifted to a single selected time. Following suppression of gallbladder filling with a fatty meal, dynamic SPECT of the hepatobiliary system was carried out by acquiring two successive studies with each head of a dual-headed camera within a 35-min period following injection of technetium-99m DISIDA. Each of the four acquired studies consisted of 60 images acquired at 6 degree intervals, spanning 360 degrees. Time-shifted studies, each consisting of 60 images over 360 degrees, were generated for times 9, 17, and 26 min postinjection. Transverse, sagittal, and coronal images were generated for each study. These images were artifact-free and demonstrated physiologic shifting of the radioactivity distribution over time. When gallbladder filling was not suppressed gross artifacts were obtained. This procedure permits examination of regional liver function and provides improved visualization of the biliary tree.

Biliary Tract

The relationship between alcoholism and neurosis: evidence from a twin study.

The twin register of the Maudsley Hospital was used to select a series of monozygotic (MZ) and same-sexed dizygotic (DZ) twins who had been given an ICD8 diagnosis related to alcoholism. They and their co-twins were traced. Medical and drinking histories were compiled (from records and by interview) for 56 twin-pairs, to permit current and retrospective diagnosis of any neurotic disorders. RDC diagnoses of panic disorder, generalised anxiety disorder, obsessive-compulsive disorder and phobias were more common in the alcoholic probands and the co-twins who were also alcoholics than in the normal-drinking co-twins. The Eysenck Personality Questionnaire (EPQ) and the Severity of Alcohol Dependence Questionnaire (SADQ) were completed by 54 individuals. Neuroticism scores were significantly higher for both male and female alcoholics than for their normal-drinking co-twins; and intra-pair differences in neuroticism were significantly correlated with intra-pair differences in severity of dependence. These results suggest that both clinically diagnosed neurotic illness and high neuroticism scores are more often a consequence than a cause of alcoholism.

Alcoholism

Uniformity correction for SPECT using a mapped cobalt-57 sheet source.

As little as 1% nonuniformity of the scintillation camera can produce disturbing artifacts in SPECT images. To correct for nonuniformity, acquired images must be divided by the flood-field image of a uniform sheet source. The refillable 99mTc sheet source requires meticulous preparation before each use, and is subject to spillage. We propose the use of a permanent 57Co solid sheet source in conjunction with a map of the radioactivity distribution in the source. The flood-field image of the cobalt source is converted by the map into the equivalent of a flood-field image of an almost perfectly uniform source. An accurate and reproducible method is described for generating a map of the cobalt sheet source from images of it made in multiple positions with the scintillation camera. The mapping process is independent of sensitivity variations across the face of the camera.

Cobalt Radioisotopes

Depression, criminality and psychopathology associated with alcoholism: evidence from a twin study.

A study of 74 twin pairs with alcoholic probands from the Maudsley Hospital is reported. Pairwise concordance for alcoholism as categorised by the SADS-L Research Diagnostic Criteria is similar in MZ twins (29%, 8/22) and DZ twins (33%, 13/39). Concordance for all diagnoses other than alcoholism is however significantly greater in MZ twins (48%, 13/27) than DZ twins (21%, 8/39, P less than 0.001). Concordance in MZ and DZ twins for all diagnoses other than alcoholism, including depression, did not coincide with concordance for alcoholism. Data on criminality revealed that 21% (32/148) of the twin sample had non-alcohol, non-traffic offences on record at the UK Home Office. Of the 32 with criminal records, 28 were alcoholic probands and pairwise concordance for criminality was found in only 1 MZ and 2 DZ pairs.

Alcoholism

Functional renal imaging through factor analysis.

Functional images tend to be noisy, since they are formed from parameter values estimated from noisy time-activity curves. Factor analysis provides a rapid method for fitting smooth curves to these noisy curves. Noise in functional images is reduced by estimating parameter values from the smooth curves. The method is illustrated for three parameters: TMAX (time to maximum value), RISE (increase from first to maximum value), and RISMX (maximum increase between successive values). When curve-fitting through factor analysis is used to generate functional renal images from clinical studies or to estimate parameter values for simulated noisy renogram curves, noise is reduced for the TMAX and RISMX parameters and accuracy is improved for the RISE parameter.

Factor Analysis, Statistical

An automated method for the alignment of image pairs.

The computer comparison of two images of the same organ requires proper alignment of the images before further computer processing. This alignment can be achieved by (a) fixing patient position during the study, (b) alignment methods using analytical transformations, or (c) operator interaction. We propose an automated method based upon the cross-correlation between projections of the images. With fast Fourier transforms, the algorithm becomes computationally cheap.

Computers

What causes lower neck uptake in bone scans?

Lower neck uptake, frequently seen on anterior views of bone scans done with 99mTc-phosphate compounds, was studied in 122 patients to determine its incidence and etiology. Increased uptake was identified in the lower neck anteriorly in 46 patients (38%). In 14 of these, moderately severe to severe arthritis appeared to cause the uptake; metastatic disease was the cause in 8 cases; and in 1 case there was prominent uptake in the thyroid cartilage. Positioning artifact accounted for the uptake in the other 23 cases. Thyroid uptake was never observed.

Adult

Nuclear imaging: a new dimension.

Tomographic techniques used in radiology have also found an application in nuclear medicine. Longtitudinal tomography blurs but does not eliminate structures outside the plane of interest. Transverse tomography eliminates out-of-plane structures, making accurate imaging possible. Positron imaging devices are well suited for transverse tomography because of their high spatial resolution and depth-independent response, but devices using a scintillation camera can visualize large volumes and are not restricted to the use of positron emitters.

Humans

The effects of diagnostic X-ray exposure on the human fetus: an examination of the evidence.

Epidemiological studies have demonstrated an increased incidence of morbidity and mortality among children exposed prenatally or preconceptually to diagnostic x-rays, as compared to nonirradiated controls. In those studies radiation exposure occurred on a selective basis, as the examination was always medically indicated. Comparisons of those studies and comparable ones in which radiation exposure occurred on a nonselective basis (from routine pelvimetry examinations or atomic bomb radiation) indicate that the latter studies do not confirm the former and a significant discrepancy is present in each instance. Thus, some doubt is cast on the validity of the former studies.

Child