Milo M. Webber

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.

Telecommunication of Images in the Practice of Diagnostic Radiology

A real-time point-to-point television system was evaluated to determine its practicality in diagnostic radiology, using ultra-high frequency radiotransmission. From the standpoint of nuclear medicine images, the system was entirely satisfactory; with radiographs, satisfactory performance required the use of close-up and zoom lenses. Such a system may be used to facilitate radiological diagnosis in areas which lack an adequate radiology service of their own.

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.

Long-term quantitative results following fundoplication and antroplasty for gastroesophageal reflux and delayed gastric emptying in children

BACKGROUND The operative management of children with combined gastroesophageal reflux and delayed gastric emptying is controversial. This study measures the long-term follow-up of gastric emptying in children who have undergone gastroesophageal fundoplication combined with antroplasty. METHODS Fifteen randomly selected children with gastroesophageal reflux and scintigraphically demonstrated delayed gastric emptying underwent fundoplication and antroplasty. Each patient had another gastric emptying scintigraphic study performed an average of 3.6 years postoperation. RESULTS All patients reported improvement of their symptoms compared with before the operation, and none required further medical therapy for gastroesophageal reflux or experienced dumping syndrome. Eleven of the 15 patients had significant long-term improvement of their gastric emptying postoperatively. The mean percent of isotope meal remaining in the stomach at 90 minutes improved from 72% preoperatively to 40% postoperatively (P = 0.0005). CONCLUSIONS Gastric emptying in children with gastroesophageal reflux and delayed gastric emptying is significantly improved for several years in three-fourths of patients after fundoplication and antroplasty. Fundoplication and concomitant antroplasty are recommended for symptomatic children with documented gastroesophageal reflux and delayed gastric emptying.

Labeled albumin aggregates for detection of clots.

Macroaggregates of albumin can be used to detect the presence of endothelial damage or clot surfaces in patients with suspected intravenous thrombosis. The method shows very few negatives when contrast venography is positive. It is recommended for use as a screening procedure: accuracy may be improved by combining the static scans of particle retention with flow studies indicating the pathways of flow. The mechanism for particle localization appears to be based either on adhesion, electrostatic forces, or less likely, mechanical entrapment. Localization of arterial lesions or capillary endothelial lesions, as in rejecting kidneys, are different manifestations of the same phenomenon. There appears to be a similarity of behavior of particles to platelets, suggesting that there may be common mechanisms to localization of both.

Radionuclide patterns of femoral head disease

Abstract The pattern of uptake of bone marrow specific radio- 99m Tc sulfur colloid and the pattern of uptake of bone mineral specific radio- 99m Tc pryophosphate may be valuable in assessing bone vascularity in diseases suspected of causing impaired blood supply, or indicate the presence of reactive bone formation. The low energy of the technetium label has been shown to be superior to 18 F and 85 Sr, and leads to greater imaging detail on the scans. Femoral head scanning with mineral and/or marrow specific radionuclides offers the clinician a method of evaluating the status of the femoral head and possibly an early diagnosis of avascular necrosis before roentgenographic changes occur. This study, which reports on a 5-year experience using radionuclide scanning to assess femoral head vascularity, begins with baseline or normal studies followed by variations of the normal pattern. Typical scan patterns of hip pathology described above are also presented.

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.

Mural Thrombosis After Experimental Carotid Endarterectomy

The incidence of mural thrombosis following three types of experimental intimal injuries at common carotid arteries, was investigated in a series of 12 dogs. Mural thrombosis was obtained at each of the intimal lesions. Moreover, obstructive thrombosis occurred in three instances. Further investigation of thrombi revealed that partial fragmentation occurred when exposed to hydrodynamic forces. These results suggest that mural thrombosis following carotid endarterectomy in humans, is possibly more frequent and significant than it is generally appreciated, thus leading to the consideration of postoperative anticoagulation after endarterectomy, as a means to minimize the incidence of postoperative embolic cerebrovascular accidents.

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.