Michael D. Cragin

THROMBOPHLEBITIS: DEMONSTRATION BY SCINTISCANNING.

We have noticed that collections of radiotracer in the axillary regions are occasionally seen in patients who have undergone pulmonary scanning (Fig. 1). Almost without exception such patients have previously been subjected to venous catheterization for the purpose of administering intravenous fluids. Accumulations of tracer generally are punctate in appearance and are seen either during the time that the catheter is in place, where injection is made through the catheter, or for several weeks following the removal of the catheter. An explanation that appeared reasonable to us was that the endothelial injury with associated clot (fibrin) deposits on the wall of the injured vessel trapped particles of albumin as they passed. An attraction for the macroaggregates of albumin by the fibrin was postulated. The thesis was tested in the laboratory by preparation of a Petri dish filled with serum mixed with macroaggregates of albumin tagged with 99mTc (Fig. 2). This experiment was interpreted as confirming the abi...

Thrombosis detection by radionuclide particle (MAA) entrapment: correlation with fibrinogen uptake and venography

Macroaggregated albumin (MAA) entrapment in areas of fibrin deposits has been used to detect intravenous thrombosis in the lower extremities. This study reports the correlation of MAA uptake in thrombosis with venography and autologous 125I-labeled fibrinogen uptake in approximately 30 cases. Correlation was good in most patients who underwent at least two of these procedures. The MAA thrombosis scan appears especially accurate in locating thrombosis in the upper thigh or pelvis where fibrinogen uptake is less helpful. The correlation suggests that the MAA scan has very few false negative results. The procedure is easily performed in conjunction with a perfusion lung scan.

Demonstration of thrombophlebitis and endothelial damage by scintiscanning.

Abstract Several particulate radiotracers were studied with respect to their behavior in the vicinity of clots. Experiments were performed in vitro, microscopically and quantitatively, and in vivo on artificially created lesions. Of the particles studied, macroaggregates of albumin and aggregates of stannous hydroxide showed the best accumulation on clots and venous lesions. It was concluded that there is definite demonstrable clot affinity for some particles and not for others. The mechanism remains to be elucidated. Clinical usefulness is to be evaluated.

Rapid Preparation of 99mTc-Labeled Albumin Macroaggregates1

Instant labeled macroaggregates of albumin (ILMAA) for lung imaging may be prepared rapidly by reduction labeling of preformed albumin macroaggregates from a stock solution. Highly efficient labeling is accomplished with a minimum of preparation time and procedural steps by using an acidified aqueous solution of SnCl2 as a reducing agent.

Rapid preparation of 99m Tc-labeled albumin macroaggregates.

Instant labeled macroaggregates of albumin (ILMAA) for lung imaging may be prepared rapidly by reduction labeling of preformed albumin macroaggregates from a stock solution. Highly efficient labeling is accomplished with a minimum of preparation time and procedural steps by using an acidified aqueous solution of SnCl2 as a reducing agent.

Radiolabeled particle entrapment in acute arterial ulcerations a computer videotape analysis

Abstract The extent and duration of Technetium-99m microaggregates of albumin entrapment in acute intimal arterial ulcerations was investigated by computer videotape analysis to determine the optimal period of time for arterial scanning.

Clinical Case Reports: THE DETECTION OF SHALLOW ARTERIAL ULCERATIONS

delayed, in part because of the absence of a reliable procedure for detecting these shallow lesions. A new method for diagnosis of these ulcerations is based upon the detection by external scanning, of radiolabeled particles entrapped in places of the artery where intimal coverage was missing. Irregular shaped electropositive 99mTechnetium albumin aggregated particles (99mTc MAA), measuring 10 to 50 microns in diameter were utilized and intraarterial

Detection of Shallow Arterial Ulceration with Radiolabeled Particles

From the Department of Surgery, University of Missouri, Kansas City, (Dr. Pollak) and the Laboratory of Nuclear Medicine and Radiation Biology, Department of Radiology, University California Los Angeles (Dr. Webber and Mr. Cragin). Presented to the forty-eighth annual scientific session of the American Heart Association, Anaheim, California, November 18, 1975. This investigation was supported by Contract AT (04-1) GEN 12 between the Atomic Energy Commission and the University of California, and by the Intercampus Opportunity Fund of the University of California. Abstract