Showing papers in "The Journal of Nuclear Medicine in 1974"

A 99mTc-chelate substitute for organoradiomercurial renal agents.

Abstract: Dimercaptosuccinate labeled with /sup 99m/Tc-pertechnetate was used for imaging renal cortical morphology. Following intravenous administration, its in vivo kinetics mimic that of /sup 203/Hg-chlormerodrin. (auth)

Renal cortical imaging in 35 patients: superior quality with 99mTc-DMSA.

Abstract: The metal chelate 2,3-dimercaptosuccinic acid (DMSA) complexed with 99mTc appears to be a superior and safe renal scintigraphic agent, regularly revealing corticomedullary morphology with either a multihole or a pinhole collimator. Fifty percent or more of administered dose is retained by the renal cortex at 1 hr—the highest proportion that has been reported for any 99mTc complex. Scintiphotos of a variety of renal diseases and preliminary kinetic data are presented.

Absolute and Relative Deficit in Total-Skeletal Calcium and Radial Bone Mineral in Osteoporosis

Abstract: There was a marked deficit in the total calcium content of the skeleton in a group of 40 osteoporotic patients as measured by total-body neutron activation analysis (TBNAA). A highly significant correlation (0.826, p In order to measure the relative deficit in total-body calcium in individual patients from the absolute calcium measurement, it was necessary to normalize the data for sex, age, and skeletal size. For this purpose an algorithm was used to predict the normal skeletal calcium in each subject based on lean-body mass, height, sex, and age. In the female osteoporotic group the mean normalized total-body calcium ratio was 0.82 compared with a mean value of 1.00 ± 0.05 (s.d.) in the contrast normal group. For patients with significant loss of height or abnormally low total-body potassium, the calcium ratio is overestimated. In a similar manner, to facilitate intercomparison of bone mineral content (BMC) measured by absorptiometry, an index of size and age is required. Whereas division of the BMC by the width of the radius (W) tends to reduce the variability in the group, it is not satisfactory as a normalizing factor. In fact, the correlation coefficient of BMC/W with the normalized total-body calcium is low: 0.454, p The large inherent variability in the bone mineral content measurement (of the radius) and the inability to normalize these data often make it unsatisfactory for evaluation of the extent of osteoporosis in an individual. The total-body calcium measurement normalized for sex, age, and skeletal size provides a more accurate technique for evaluating the loss of bone mass and hence is a more useful index for quantitating the degree of osteoporosis in an individual.

Radiotechnetium polyphosphate joint imaging.

Abstract: An assessment of the efficacy of 99”Tc-poly phosphate (IImTcPP) in the disclosure of syno vitis in 27 patients is presented. A comparison was made between °9@”TcPP, clinical evaluation, 99mT@fJ4, and radiography. in general 9OmTcPP was found to be more sensitive in the detection of inflammatory synovitis in peripheral joints than the other three methods, but it is also non specific as increased periarticular accretions were found in degenerative osteoarthritis, meta bolic bone disease, and trauma. Although O9mTcpp joint imaging qualifies as a screening procedure, regions of increased uptake should be radiographed to determine whether other causative factors exist.

Imaging functional nodules of the adrenal glands with 131-I-19-iodocholesterol.

Abstract: Only in the instance of the hyperfunctioning adrenal cortical adenoma with Cushing's syndrome is the uptake of the /sup 131/I-19iodocholesterol markedly decreased to absent in the adrenal cortices outside the adenoma. The mechanism for this lack of function outside the hyperfunctioning adrenal cortical adenoma presumably is suppression of pituitary ACTH by cortisol excess from the adrenal cortical adenoma resulting in subnormal stimulation of normal adrenocortical tissue. We report the occurrence of hyperactivity in one adrenal gland presumably from a functioning nodule, resulting in increased uptake with suppressed uptake of /sup 131/I-l9-iodocholesterol in the contralateral adrenal cortex in the absence of Cushing's syndrome. One 67-year-old woman had diabetes mellitus, a massively fatty liver, a dexamethasone nonsuppressible uptake of /sup 131/I-19-iodocholesterol in her right adrenal nodule, and a normal response to ACTH stimulation of the opposite adrenal gland. A 21-year-old woman had obesity, diabetes, progressive hirsuitism, sterility, and slightly elevated urinary 17- ketosteroid excretion. The increased uptake in the hot nodule in the right adrenal was suppressible with dexamethasone and ACTH produced a normal uptake in the opposite adrenal gland. The similarity of these functional nodules in more » the adrenal cortices to functional nodules previously observed in the thyroid gland with /sup 131/I is apparent. (auth) « less

Optimization of the ratio of stannous tin: ethane-1-hydroxy-1, 1-diphosphonate for bone scanning with 99mTc-pertechnetate.

Abstract: BS>Using synthetic hydroxyapatite (HA) as an in vitro skeletal model, the optimum formulation of a /sup 99m/Tc-distannous ethane1-hydroxy-1, 1- diphosphonate (/sup 99m/Tc --Sn - EHDP) bone scanning agent was determined by measurement of the amount of radiotagged components (/sup 99m/Tc, /sup 113/Sn, and 1-/sup 14/C --EHDP) on HA. A range of EHDP to stannous chloride weight ratios (5: 1 to 50: 1) was found to yield complete (>95%) sorption on HA of the / sup 99m/Tc-Sn -EHDP bone scanning agent. Using the 12: 1 and 50: 1 ratios, organ distribution and blood clearance for 1-/sup 14/C--EHDP, /sup 113/Sn, and /sup 99m/ Tc were determined in Sprague --Dawley rats. Major whole organs, selected skeletal samples, urine, and feces were assayed by liquid scintillation and gamma spectrometers. The /sup 99m/Tc--Sn EHDP agent was found to be nearly evenly distributed between the skeleton and urine with less than 2% of the dose in soft tissue. The /sup 99m/Tc --Sn - EHDP agent yielded excellent scintiscans of the skeletal system. The rapid blood clearance is comparable to /sup 18/F, and the physical and chemical properties of the diphosphonate agent suggest an advantage over the /sup 99m/Tc-labeled polyphosphate or pyrophosphate bone scanning agents. (auth)

Scintiscanning of pulmonary diseases with 67Ga-citrate.

Abstract: Scintiscanning with /sup 67/Ga-citrate was performed in 162 patients with various pulmonary diseases. Of the 70 cases of primary pulmonary carcinoma, 62 had a strongly positive and 7 a slightly positive scan and all 18 cases of metastatic pulmonary carcinoma had a positive scan, including a carcinoma of 1 to 2 cm in diam. According to the histopathological findings, the positive rate for squamous cell carcinoma and undifferentiated carcinoma tended to be higher than that for adenocarcinoma. By indicating the presence of infiltration of lymphatic metastasis in the mediastinum for which the roentgenologic diagnosis is difficult or a tumor which overlaps the heart shadow or is hidden in a large hydrothorax, / sup 67/Ga-citrate scanning has contributed valuable information on which to base a decision for operating or choice of surgical method and the establishment of the range of radiotherapy. Otherwise inflammatory lesions (pneumonia, purulent pulmonary infection, pulmonary tuberculosts, etc.) and sarcoidosis had more clearly positive scans in the acute stage than did carcinoma. (auth)

Quantitative Effects of Stationary Linear Image Processing on Noise and Resolution of Structure in Radionuclide Images

Abstract: Processing radionuclide image data in an attempt to improve its diagnostic usefulness inevitably changes both the noise and the resolution of structures in the image. Although at present little conclusive evidence exists to indicate whether or not image processing is beneficial, an understanding of the quantitative effects of various processing techniques on parameters of resolution, noise magnitude, and noise texture seems to provide a useful beginning towards solution of the more difficult problem of understanding the effects of image processing on diagnostic image quality. Quantitative effects of stationary linear image processing procedures, which include all convolutions and filtering operations, can be predicted rather simply. In the present work, expressions for predicting these quantitative effects are developed and are applied to computer-synthesized image data to provide illustrative examples of the effects of typical noise-smoothing and resolutionenhancing operations. (auth)

67Ga-Citrate Imaging in Untreated Primary Lung Cancer: Preliminary Report of Cooperative Group

Abstract: An interinstitutional cooperative study has been undertaken to evaluate 67Ga as a tumor-localizing agent. A uniform protocol and computer handling of data have been used. In 172 untreated patients with primary lung cancer, approximately 84% had one or more sites demonstrated on scanning with 67Ga; 80% of individual lesions histologically verified had positive scans. It is occasionally possible to detect rather small lesions and, conversely, on occasion to miss some large lesions (5 cm or larger). Negative scans were obtained in 16% of lesions histologically proven. In the present analyses, rates of detection differ somewhat according to histologic type but not strikingly. With further developments in tumor-localizing agents and instruments, the agent may eventually be useful in the initial diagnostic workup of suspected lung carcinoma in certain clinical situations. As a single screening scan procedure, it should prove helpful in assessing the extent of disease before surgery or other type of therapy.

“Cold” Bone Lesions: A Newly Recognized Phenomenon of Bone Imaging

Abstract: “Cold” (photon-deficient) bone scan lesions are reported in seven patients with a variety of disease processes including metastatic disease, post-traumatic aseptic necrosis, and sickle cell-C crisis. Patients were studied with 99mTc-polyphosphate and/or 18F scans and in two cases, 111In-chloride bone marrow scans. Foci of decreased radioisotope activity were identified corresponding to sites of metastatic tumor and bone infarcts. Infarction may be a primary mechanism in the production of diminished radionuclide uptake in some of the cases. Consideration is given to a spectrum of abnormal bone-imaging manifestations (increased uptake, “normal” uptake, to photon-deficient) as a useful concept in the interpretation and understanding of bone scans.

A Low-Energy Multihole Converging Collimator Compared with a Pinhole Collimator

Abstract: It is apparent from the equations describing the performance of the pinhole and converging collimators on the scintillation camera that the sensitivity, resolution, and field of view of these two collimators are very different as a function of distance from the collimator face. A 6000-hole converging collimator designed for /sup 99m/Tc havin a 15-cm field of view diameter at 10 cm from the collimator face was constructed and compared with the Searle Radiographicas pinhole collimator. The sensitivity of the converging collimator increases with depth while that of the pinhole collimator decreases. The resolution of the collimator-camera system degrades more rapidly with depth fur the pinhole collamator. The field of view of the converging collimator decreases with increasing object-tocollimator distances while that of the pinhole collimator increase with depth. The experimental results agree with the derived equations and imply that the converging collimator has very different performance characteristics from the pinhole collimator and that it should be useful in the imaging of small organs. (auth)

Radionuclide venography (RNV) in lower extremity venous disease.

Abstract: Radionuclide venography (RNV) of the pelvis and lower extremity veins using /sup 99/Tc-albumin microspheres was performed in 53 patients with pulmonary emboli or venous disease. In 25 patients who underwent both contrast radiography and RNV studies, there were no false-positive studies and one false-negative. In this series the accuracy of RNV exceeded that of Doppler alone. When the results of these two methods were combined, falsenegative studies were eliminated. Over half the patients with pulmonary emboli and clinically normal lower extremities had abnormal RNV studies. The exact method of thrombus localization is not known but both mechanical and electrostatic factors may be involved. RNV has been shown to be a safe, accurate, and easily performed examination that is particularly useful in evaluating patients with pulmonary emboli. (auth)

Pulmonary veno-occlusive disease.

Abstract: Pulmonary veno-occlusive disease (PVOD) is characterized by the blockage (occlusion) of the blood vessels that carry oxygen-rich (oxygenated) blood from the lungs to the heart (the pulmonary veins). The occlusion is caused by a buildup of abnormal fibrous tissue in the small veins in the lungs, which narrows the vessels and impairs blood flow. Because blood flow through the lungs is difficult, pressure rises in the vessels that carry blood that needs to be oxygenated to the lungs from the heart (the pulmonary arteries). Increased pressure in these vessels is known as pulmonary arterial hypertension.

Clinical Applications of a Kinetic Model of Hippurate Distribution and Renal Clearance

Abstract: Measurements of effective renal plasma flow and urine flow fractions were obtained by the application of a new kinetic model of /sup 131/I-labeled o- iodo-hippurate distribution and renal clearance. Good agreement was obtained between these estimates and those of comparable parameters obtained by conventional split-function techniques using p-aminohippurate and inulin. Also, examples are presented of the use of this test for the evaluation of patients suffering from well-documented renal diseases. These uses have included serial testing in patients with major renal artery occlusion, bilateral renal vein thrombosis, obstruction due to stone, or transplant rejection. It was concluded that this test can be of considerable value for the diagnosis of acute and chronic disorders of renal function and for evaluation of the therapeutic response. In addition, these studies have demonstrated the potential of large computers for parameter estimation in the interpretation of nuclear medicine procedures. (auth)