Michael L Goris
Stanford University, Nuclear Medicine, Department Member
Selection of a nuclear medicine computer system is a process that should be approached with care and forethought. The general scheme should be to define your needs and constraints, determine what is available, investigate the leading... more
Selection of a nuclear medicine computer system is a process that should be approached with care and forethought. The general scheme should be to define your needs and constraints, determine what is available, investigate the leading candidates, make a site visit, and, finally, submit an order. Through a series of discussions between members of the Computer Council of the Society of Nuclear Medicine and representatives from the manufacturers of computer systems, a set of important considerations emerged, which are reported in this paper. This paper is not intended to be a step-by-step guideline to the purchase of a computer system. Rather, it is a set of concepts and considerations with which the prospective purchaser should be familiar before undertaking such a purchase.
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Research Interests: Cardiology, Adolescent, Medicine, Echocardiography, Heart Failure, and 15 moreTransplantation, Methods, Humans, Internal Medicine, Female, Male, Heart, Clinical Sciences, Heart valves, Adult, Heart Transplantation, Vascular Resistance, Cardiac output, Cardiovascular medicine and haematology, and ventricle
The 38C13 murine B cell lymphoma model was used to study the effect of the preinjection of unlabelled anti-idiotype monoclonal antibody (mAb) on the subsequent biodistribution of 131I-anti-idiotype mAb. Mice with established tumors... more
The 38C13 murine B cell lymphoma model was used to study the effect of the preinjection of unlabelled anti-idiotype monoclonal antibody (mAb) on the subsequent biodistribution of 131I-anti-idiotype mAb. Mice with established tumors received 0-500 micrograms of unlabelled anti-idiotype mAb 24 h prior to the administration of 131I-anti-idiotype (specific), or both 125I-anti-idiotype and 131I-isotype-matched irrelevant control (nonspecific) mAb. Mice were counted daily in a gamma counter and sacrificed at 2-144 h following injection. Mice were dissected and the weight and activity of the animals and organs were measured. Mice were bled periodically and circulating idiotype levels were measured using an ELISA assay. Five hundred micrograms of unlabelled anti-idiotype mAb increased the retention time of the specific but not the nonspecific mAb in all organs and tumor. Following pretreatment with unlabelled mAb, the cumulative tumor/whole body and tumor/normal organ ratios became similar to those of the nonspecific mAb, with concentration ratios (specific/nonspecific mAb) of approximately 1, which persisted until 96 h post injection when circulating idiotype reappears in antigen excess. In the absence of unlabelled mAb there was less retention in tumor and normal tissue. This is presumed to be due in part to decreased levels of circulating 131I-mAb secondary to rapid plasma clearance of antigen-antibody complexes and tumor cell mediated dehalogenation, which results when the specific mAb specifically binds the targeted antigen. Thus, the addition of unlabelled mAb increased the retention by decreasing the specific behavior of the anti-idiotypic antibody.
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ABSTRACT
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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... more
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.
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We propose a method to assess an attenuation correction method in myocardial perfusion SPECT. Three types of images are obtained: one resulting from a classic acquisition and filtered back-projection (classic), and those resulting from... more
We propose a method to assess an attenuation correction method in myocardial perfusion SPECT. Three types of images are obtained: one resulting from a classic acquisition and filtered back-projection (classic), and those resulting from acquisition with a transmission source and an iterative reconstruction, with (music) or without (hybrid) the attenuation correction factored in to compare the three types of images and classify them as normal or abnormal, a three dimensional inter-patient quantitative comparison method was used. Differences were computed as fractions of the myocardial volume in which density differences are significant by population standards. In 7 cases the cumulative difference between prone and supine in hybrid images was 124 and 45 in music images. In 10 cases the cumulative difference between classic vs music images was 279, and between classic and hybrid 86. The AC changed 4/12 cases from abnormal to normal. The attenuation correction effect was concentrated on ...
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Using the angiographic findings as the standard, we have examined the sensitivity and specificity of ECG-gated static thallium-201 myocardial images in 54 patients undergoing selective coronary arteriography. Gated and nongated images,... more
Using the angiographic findings as the standard, we have examined the sensitivity and specificity of ECG-gated static thallium-201 myocardial images in 54 patients undergoing selective coronary arteriography. Gated and nongated images, each in anterior, 45 degrees LAO, and 65 degrees LAO projections, were processed by interpolative background subtraction. They were then analyzed separately by four independent observers who were unaware of patient identity, the results of coronary arteriography, and which studies were gated or nongated. No significant differences were observed between the gated and nongated images regarding sensitivity or specificity, the detection rate for reversible myocardial ischemia, the accuracy of prediction of arteriographic extent of disease, or the degree of inter- or intraobserver variability. We conclude that ECG-gated acquisition of T1-201 images does not produce any significant advantages, at least when interpolative background subtraction is used.
Research Interests: Cardiovascular disease, Medicine, Electrocardiography, Humans, Beta decay, and 15 moreFemale, Male, Heart, Background Subtraction, Clinical Sciences, Angiography, Aged, Cardiovascular system, Electrocardiogram, Adult, Ischemic Heart Disease, Coronary Artery Disease, Detection Rate, Blood Vessel, and Diagnostic errors
The purpose of single photon emission computed tomography (SPECT) data is to map the tracer concentration from the three-dimensional object into a three-dimensional image array. The conventional interrogation of the data is through slice... more
The purpose of single photon emission computed tomography (SPECT) data is to map the tracer concentration from the three-dimensional object into a three-dimensional image array. The conventional interrogation of the data is through slice interrogation. In this paper we explore display methods in which the data are directly interrogated and processed as three-dimensional data. This includes direct addressing of sagittal, transverse, and frontal slices, around a targeted subvolume, and direct addressing of nonorthogonal slices. The three-dimensional aspect of the data is further accommodated by thresholding and edge definition in space. Finally, morphological information, which is sparse in scintigraphic slices, is recaptured by the generation of planar data derived from data processed in the three-dimensional space.
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A method to define biodistribution from planar scintigraphic data is presented. Sampling regions or regions of interest (ROI's) are first defined as the projection contour of organs. From anatomical knowledge the three dimensional... more
A method to define biodistribution from planar scintigraphic data is presented. Sampling regions or regions of interest (ROI's) are first defined as the projection contour of organs. From anatomical knowledge the three dimensional volume of the organ whose shadow has been traced is reconstructed. When the relevant organ volumes including the whole body or relevant whole body part have been defined, the count rate density in each pixel is assumed to represent the sum of the product of the projecting organ partial volumes times the tracer concentrations in the underlying organs. The solution (the definition of organ concentrations) is found by a matrix inversion. Validation is obtained in two ways. The first method is illustrative: an image is reconstructed from the defined volumes modulated by the computed concentrations. This image, if the method is correct, should be a crisp equivalent of the original data and closely similar to it following blurring with a convolution kernel e...
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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... more
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.
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A method for the evaluation of regional lung ventilation using 81mKr eluted from a rubidium generator is described. The tracer distribution at equilibrium is a function of regional ventilation, not of volumes. The study can be performed... more
A method for the evaluation of regional lung ventilation using 81mKr eluted from a rubidium generator is described. The tracer distribution at equilibrium is a function of regional ventilation, not of volumes. The study can be performed on a wide range of patients, including unconscious and mechanically ventilated patients, and can be performed immediately following or concurrently with a perfusion study. Thus, precisely comparable ventilation and perfusion images can be obtained.
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Features extracted from static or dynamic scintigraphic images can be used to produce parametric or functional images. Those images typically map a dynamic parameter (temporal encoding) or a quantitative measure of the tracer... more
Features extracted from static or dynamic scintigraphic images can be used to produce parametric or functional images. Those images typically map a dynamic parameter (temporal encoding) or a quantitative measure of the tracer distribution. In this report, we consider the cases in which the nature of the extracted feature is well suited for a quantitative normative evaluation, ie, where the values obtained can be directly or indirectly compared with expected normal values. The major difference between this approach and the more common heuristic or synoptic interpretation of "images" lies in the underlying modeling: the model "predicts" a minimal washout rate, a match between ventilation and perfusion rates in the lungs, homogeneous contraction in the left ventricle, an expected angular distribution of thallium in the myocardium, or the absence of an additional kinetic feature. The quantitative aspect of the analysis is based in all cases on an approach that overcomes or is less sensitive to morphological or structural biological variability: in some cases the patient provides the normalizing data, as in ventilation-perfusion ratios. In other cases, the model predicts homogeneous results (as in phase analysis) or a range of normal physiological values (for xenon washout). Less commonly, the analysis requires a transformation of the data, as is the case in the analysis of myocardial perfusion, which follows a polar transformation of the image, and an analysis based on angular coordinates. In a normative approach, pathology is defined as a deviation (in this case a quantitative deviation) from the norm. The next step is to model specific abnormalities: early right-sided reappearance of the bolus in a right-to-left shunt, the appearance of "abnormal" kinetic factors, or a comparison with the expected distribution of bloodflow (or location of defects) in certain coronary lesions. However, in all cases, one should note that the analysis does not compromise the major feature of "imaging," that is to recognize regional, rather than exclusively global malfunction.
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The use of skeletal scintigraphy for the detection of metastatic disease of the bone is reviewed. The review is based on published data for sensitivity, specificity, yield and prognostic value. The analysis, and interpretation of... more
The use of skeletal scintigraphy for the detection of metastatic disease of the bone is reviewed. The review is based on published data for sensitivity, specificity, yield and prognostic value. The analysis, and interpretation of published data is complicated by the variation in criteria. It appears nonetheless, that for a number of tumors the relative (in comparison with other methods) and absolute (based on outcome prediction) sensitivity is high. For certain tumors in early stages, and in asymptomatic patients the yield (of positive studies) is low, even when the prognostic value is high. Those factors should be weighed with the availability of therapeutic options to determine the clinical efficacy of skeletal scintigraphy.
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Research Interests: Cognitive Science, Radiology, Biomedical Engineering, Statistical Analysis, Magnetic Resonance Imaging, and 12 moreMedicine, Pulmonary Embolism, Magnetic Resonance, Animal Model, ROC Curve, Clinical Sciences, Gold Standard, Experimental, Polyethylene Glycol, MR Angiography, Nuclear Magnetic Resonance Imaging, and Contrast Media
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... more
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.
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Research Interests: Medicine, Occult, Humans, Male, Clinical Sciences, and 8 moreAged, Middle Aged, Radioisotopes, Suspect, Abscess, Leukocytes, Indium, and Heart Diseases
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Research Interests: Cardiology, Medicine, Electrocardiography, Echocardiography, Humans, and 15 moreInternal Medicine, Male, Heart, Cardiac Catheterization, Adult, Cardiomyopathy, Physical examination, Cardiomyopathies, Ejection Fraction, Heart Transplantation, Cardiac Transplantation, The American, Cardiac output, Cardiovascular medicine and haematology, and Mitral valve
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Research Interests: Nuclear medicine, Apoptosis, Medicine, Ischemia, Mice, and 15 moreAnimals, Microglia, Male, In Vivo Imaging, Clinical Sciences, In Vivo, Radiopharmaceuticals, Infarct Size, Minocycline, Neuroprotective Agents, Experimental Model, Neuronal apoptosis, penumbra, Annexin, and Middle cerebral artery occlusion
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S OF CURRENT LITERATURE 2.9). Following the administration of a single dose of either L-triiodothyronine (T:) or of L-reverse-T:, a measurable rise in T2 was observed. The authors concluded that T2, whose physiological importance is... more
S OF CURRENT LITERATURE 2.9). Following the administration of a single dose of either L-triiodothyronine (T:) or of L-reverse-T:, a measurable rise in T2 was observed. The authors concluded that T2, whose physiological importance is unknown at this time, was a normal component of human serum and amniotic fluid. The peripheral metabolism of T:i and reverse-T: to form T, con tributed significantly to levels of T2 detected. Bleomycin Serum Pharmacokineticsas Determined by a Radio immunoassay and a Microbiologic Assay in a Patient with Com promised Renal Function. S. T. Crooke, F. Luft, A. Broughton, J. Strong, K. Casson,and L. Einhorn.Cancer 39: 1430—1434, 1977. This study reports the pharmacokinetics of bleomycin in doses of 7.5 units/rn1 in a 24-year-old male who had an orchiectomy and retroperitoneal node dissection for em bryonal cell testicular carcinoma. Serum and plasma bleo mycin was assayed by existing microbiologic assay and ra dioimmunoassay (RIA). Between microbiologic an...
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A patient with high clinical suspicion for pulmonary embolism underwent a diagnostic scintigraphic ventilation/perfusion scan. The planar images revealed an unmatched perfusion defect with a stripe sign in the right middle lobe. A stripe... more
A patient with high clinical suspicion for pulmonary embolism underwent a diagnostic scintigraphic ventilation/perfusion scan. The planar images revealed an unmatched perfusion defect with a stripe sign in the right middle lobe. A stripe sign is the appearance of normally perfused tissue between the defect and the pleural surface suggesting a nonpleural-based abnormality. SPECT images acquired in the same study period, however, failed to demonstrate normally perfused tissue between the defect and the pleural surface. Previous studies have compared planar ventilation/perfusion studies with stripe sign perfusion defects to pulmonary angiography. The results suggest that stripe sign perfusion defects are generally not due to emboli. However, planar imaging is projectional and may miss pleural contact in some perfusion lesions depending on the projection. In the absence of SPECT data, the significance of the stripe sign may need to be reassessed.
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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... more
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. Th...
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Research Interests: Nuclear medicine, Medicine, Dogs, Animals, Heart, and 3 moreClinical Sciences, Thallium, and Radioisotopes
The diagnostic information in scintigraphic images is generally not contained in specific morphological image attributes, but in the regional distribution of count rate densities across the organ volumes. In a subclass of scintigraphic... more
The diagnostic information in scintigraphic images is generally not contained in specific morphological image attributes, but in the regional distribution of count rate densities across the organ volumes. In a subclass of scintigraphic images, the evaluation is actually based on a dual comparison.
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Research Interests: Cardiology, Medicine, Electrocardiography, Humans, Placebo, and 15 moreBlood Pressure, Heart rate, Heart, Placebos, Aged, Middle Aged, Angina pectoris, Drug evaluation, Propranolol, Ejection Fraction, Left Ventricular Function, Angina, Random Allocation, Pharmacology and pharmaceutical sciences, and physical exertion
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The purpose of the study is to describe a method for the investigation of myocardial kinetics (wall motion or wall thickening) to define myocardial perfusion characteristics further. The data are myocardial perfusion single photon... more
The purpose of the study is to describe a method for the investigation of myocardial kinetics (wall motion or wall thickening) to define myocardial perfusion characteristics further. The data are myocardial perfusion single photon emission computed tomographic images gated in eight time bins, following the administration of a 99Tcm-labelled perfusion agent. Wall motion is defined by the phase and amplitude of the centripetal motion of the first moment of the myocardial count rate density distribution along a radius originating in the centre of the left ventricular cavity. Wall thickening is defined by phase and amplitude of the changes in the second moment of the density distribution along the radius multiplied by the maximum density. Wall motion amplitude was abnormal in 28% of transient and 43% of fixed perfusion abnormalities, phase delays were present in 28 and 57%, respectively. Wall thickening was abnormal in amplitude in 14% of transient and 86% of fixed perfusion abnormalities. We conclude that the positive predictive value of wall-thickening abnormalities relative to fixed perfusion abnormalities is high (86%). Whether fixed perfusion defects with normal wall thickening represent viable myocardium remains to be investigated.
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To the Editor. —In his review of Oregon's methods for cost containment, Dr Eddy 1 argues with his usual clarity that the failure was due to errors in the data (specifically cost data errors and imprecision in Quality of Well-Being... more
To the Editor. —In his review of Oregon's methods for cost containment, Dr Eddy 1 argues with his usual clarity that the failure was due to errors in the data (specifically cost data errors and imprecision in Quality of Well-Being Scale state definitions), the omission of important value elements (eg, the Rule of Rescue or the vicarious utility), and the misapplication of one particular method, directed toward "egalitarian" goals, when another priority setting should have been adopted. His argument does not allow for inherent failures or shortcomings of cost analysis per se. But in his defense he should have, while in the process of allowing for multiple-weighting factors and cost or benefit scales, at least asked the question whether the numerical expressions of the different scales and weighting values form numbering systems that are isomorphic to each other. If they are not, accurate estimates of all the value systems