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Biomedical subjects

M L Goris

Publications and source records attributed to M L Goris.

86 records · Page 5Linked to original sources
PubMed1977

Suitability of radiopharmaceuticals for determining right-to-left shunting: concise communication.

Right-to-left shunting in noncyanotic patients was quantitated following the injection of either 99mTc-microspheres, 99mTc-macroaggregated albumin, or 113mIn-Fe(OH)3 particles. Shunting was determined by wholebody scanning followed by estimation of the nuclide fraction located in the systemic circulation. Both 99mTc-labeled radiopharmaceuticals yielded results consistent with normal pulmonary shunting in a noncyanotic patient, whereas 113mIn-Fe(OH)3 was less satisfactory. If the onset of scanning was delayed, however, the calculated shunt can be falsely elevated as the pulmonary particles fragment and pass onward or as the label is released. Consequently, proper choice of radiopharmaceutical and prompt scanning are crucial for accurate quantitation of right-to-left shunting.

Adolescent↗
PubMed1976

Indium bone marrow scintigraphy as an aid in selecting marrow biopsy sites for the evaluation of marrow elements in patients with lymphoma.

One hundred and two previously treated lymphoma patients were studied with 111Indium bone marrow scans and bone marrow biopsies. The biopsies were considered to represent sampling errors when the cellularity of the biopsy did not reflect the general state of the marrow organ cellularity as demonstrated by the scan. In each instance the accuracy of the scan was confirmed by either another biopsy or the subsequent clinical course of the patient. Sampling errors were infrequent (1/51) in patients with normal peripheral blood counts and whose marrow had never been involved with tumor. Errors were especially likely (17/51) in patients who had had marrow involvement or those who had anemia, leukopenia, or thrombocytopenia. The 111Indium bone marrow scan allows the clinician to avoid selecting a biopsy site with a high risk for sampling error.

Adult↗
PubMed1976

The accuracy of 111InCl3 as a bone marrow scanning agent.

The number of normal cellular elements present in bone marrow biopsies was compared to the extent of uptake at corresponding sites on 111InCl3 bone marrow scans in 87 patients with malignant lymphoma. Of the biopsies free of tumor, 49/54 interpreted as normocellular and 16/17 hypocellular or aplastic confirmed the scan interpretation. Of the biopsies demonstrating tumor, 10/11 of those interpreted as normocellular and 14/15 hypocellular or aplastic confirmed the scan interpretation. The 111InCl3 bone marrow scan is accurate in depicting the presence or absence of normal marrow elements, but is of value in detecting tumor only when the normal elements are extensively replaced.

Biopsy↗
PubMed1976

Maxillary-facial abnormalities assessed by bone imaging.

Eighty-eight patients with maxillary-facial abnormalities were studied with 99mTc-labeled phosphate compounds. Straight and tilted anterior views plus oblique orbital and lateral views were correlated with 201 thallium transmission images of a dried skull. Interpretation of any single view may be hampered by various superimposed structures. Careful patient positioning with multiple views allows for parallactic correlation which is crucial if radiotherapy, biopsy, or corroborative studies are planned.

Adult↗
PubMed1976

Interpolative background subtraction.

A method for background subtraction is presented. The data are digitized scintigraphic images, stored in 64 X 64 frames. Within this array a rectangular area surrounding the target is defined. All data points outside of this area are set equal to zero. From each data point within the area, the computer subtracts a background value equal to the average of the two intersecting linear interpolations between the values at the edges of the rectangular area having the ordinate and abscissa values of the point of interest. The rationale for this approach is discussed and its application in myocardial perfusion studies is illustrated.

Adult↗
PubMed1975

Vesicle interactions with polyamino acids and antibody: in vitro and in vivo studies.

Artificial spherules or vesicles of 900 A in diameter formed from phosphatidylcholine and gangliosides and enclosing 99mTcO4 - (standard preparation) survive intact in the circulation of the mouse. Polyamino acids and protein have been incorporated into and onto the vesicles; such vesicles remain intact as determined by diffusion dialysis studies and by electron paramagnetic resonance studies of vesicles enclosing spin label. In studying the distribution of polyamino acid-vesicles and protein vesicles in vivo, it was found that the latter distribute differently from standard vesicles or free protein alone whereas aromatic polyamino acid-vesicles concentrate in the liver and spleen to a greater extent than standard vesicles. We conclude that the permeability and stability characteristics of vesicles may be preserved when they are modified by the addition of protein or polyamino acids and that such modification of vesicles may be associated with an alteration of their fate in vivo. The potential exists to use vesicles as carriers of radiopharmaceuticals and other drugs and to direct the vesicles preferentially to tissue targets in vivo.

Animals↗
PubMed1975

In vivo distribution of vesicles loaded with radiopharmaceuticals: a study of different routes of administration.

The in vivo distribution of vesicles containing radiopharmaceuticals in their cavities has been studied using three routes of administration: intravenous, subcutaneous, and intraperitoneal. The in vivo distribution in mice was determined by dissection of the animals and calculation of radioactivity in the organs. In rats the in vivo distribution was assessed by scintigraphy using a scintillation camera-digital computer unit. After intravenous injection of vesicles, radioactivity is concentrated to some extent in the liver and spleen but the pattern of distribution is different from that of the corresponding free radiopharmaceutical or radiocolloid made of the corresponding radionuclide. The permeability of the vesicular membrane to contained radiopharmaceutical has been shown to vary according to the chemical composition of the vesicles. Vesicles can be used to introduce materials in vivo and the potential exists for their specific targeting by coupling other molecules to their surfaces.

Animals↗
PubMedDate not supplied

A thresholding for radionuclide angiocardiography.

A thresholding algorithm for nuclear angiocardiographic studies is presented. The algorithm is free of operator intervention. The threshold is defined on the basis of the distribution of picture elements with decreasing count rates during systole. The application is valid for first-pass and equilibrium ECG gated studies. Reproducibility by different operators with various degrees of experience is high; concordance of the results with those of contrast studies is within the published ranges. The method provides a reliable step in full automation and standardization of scintigraphic angiocardiographies.

Heart↗
PubMedDate not supplied

A stochastic interpretation of thallium myocardial perfusion scintigraphy.

A method is presented for the quantitative interpretation of thallium-201 myocardial perfusion studies. The data are planar images collected immediately following the stress injection, and 4 to 6 hours later. Data analysis consists of preprocessing, including thresholding of the original data, and data reduction using a variant of the circumferential profile methods. The profiles are subdivided into segments, and for each segment the difference between the norm and the actual data is computed. This difference is a quantitative symptom, whose size is assumed to be related to the probability of having the disease. The relationship between the size of the symptom in each of nine segments (three segments/view in three views) and the probability of disease is expressed in a table in which for 30 diseases (combinations of vascular lesions) the sensitivity for each of the nine symptoms is described as a Gaussian function whose average and standard deviation are computed from previous validated cases. Using an arbitrary prevalence, the post-testing probability can then be computed using Bayes' formula sequentially. The sensitivities, however, are not expressed as a binary function of the presence or absence of a symptom, but as a distribution function defined by experience. The method is sensitive for the detection of isolated left anterior descending disease (100%) and triple vessel disease (96%). When specific combinations of vascular lesions are recognized the specificity increases from 79% (when unspecified abnormalities are recognized) to 87% when left anterior descending disease or triple vessel disease is recognized.(ABSTRACT TRUNCATED AT 250 WORDS)

Bayes Theorem↗
PubMedDate not supplied

Case report: diffuse gastrointestinal bleeding.

Diffuse gastrointestinal bleeding in an immunodeficient patient is presented. Two hours after in vivo erythrocyte labeling, abnormal activity was observed in the wall of a distended colon. If this abnormal concentration had been luminal, a focal, surgically treatable lesion could not have been excluded. This pattern of hemorrhagic colonic lesions has been described pathologically, but not scintigraphically, in immune deficient patients.

Bone Marrow Transplantation↗