Gamma Camera Scintigraphy Research Articles

Intrahepatic Kinetics of lndium-111-Labelled Platelets

The intrahepatic kinetics of 111indium-labelled platelets have been studied using dynamic gamma camera scintigraphy immediately following injection. Platelets labelled in saline with 111In-oxine or 111In-acetylacetonate underwent rapidly reversible hepatic sequestration, indicating that they were "activated". Platelets labelled in plasma with 111In-tropolonate, however, did not display this phenomenon. On the assumption that plasma-labelled platelets display a normal initial bio-distribution, mean intrahepatic platelet transit time, as a factor of the transit time of 99m-Tc labelled red cells, was 1.45 +/- SE 0.12 (n = 6), implying the normal presence of a small intrahepatic platelet pool. Unlike the liver, transit through the spleen was not sensitive to the labelling medium; thus the mean intrasplenic transit time of plasma-labelled platelets was 9.3 +/- SE 0.7 min (n = 10), and of saline-labelled platelets 9.5 +/- SE 0.3 min (n = 8).

Gamma-camera scintigraphy in the diagnosis of graft ureter obstruction after renal allograft transplantation

Gamma-camera scintigraphy studies in five patients with graft ureter obstruction are presented. The isotope used was 131I-hippuranR. The diagnosis was suspected when an accumulation of activity in the pelvic region was seen, and it was in all five patients confirmed at surgery or intravenous urography.

Gamma camera scintigraphy in the diagnosis of lymphocele following renal transplantation

The symptoms and diagnosis of perirenal lymphocele following kidney transplantation are discussed. A case demonstrated by means of i.v. urography and gamma camera scintigraphy is reported. The value of the last mentioned method is stressed.

Physiologic and biologic behavior of autologous canine 131L-fibrinogen labeled by a chloramine-T method.

Autologous canine 131I-fibrinogen labeled by a chloramine-T method was examined to determine whether the fibrinogen had been altered by the iodination procedure as suggested by other investigators. Before and after radioiodination, clottability of the fibrinogen was always equal to or greater than 89 percent. Gel chromatography studies revealed that labeled fibrinogen behaved as unlabeled fibrinogen and no high molecular weight material was found. Gamma camera scintigraphy reflected the chromatography results, as iodinated material did not appear in the liver or spleen until 48 to 72 hours. The slow-moving component of the whole blood clearance curves, respresenting undenatured fibrinogen, had a mean half-life of 61.4 +/- 5.1 hours (+/- S.E.M.) and comprised 51.5 +/- 7.5 percent of the initial activity. Similarly, a mean falf-life of 53.4 +/- 2.0 hours and 59.6 +/- 7.7 percent initial activity wwere attributed to fibrinogen according to the plasma clearance curves as determined by trichloracetic acid precipitation. The results clearly demonstrated that chloramine-T iodination of fibrinogen can yield an excellent product, biologically and chemically, which is free from macroaggregates.

The Diagnosis of Urinary Extravasation Using Gammacamera Scintigraphy

Gammacamera scintigraphy studies in three patients with urinary extravasation following renal transplantation are presented. Images were obtained using 131I-orthoiodohippurate. Urinary leakage were detected in each case. The diagnosis were in all three cases confirmed at surgery.

Haemophlic arthropathy surveyed with whole-body gamma-camera scinitgraphy.

A number of joints suffering from haemophilic arthropathy was studied. They were surveyed clinically, radiologically, and with a new system of whole-body gamma-camera scintigraphy. This radio-isotopic technique provides advantages such as sensitivity, speed and safety. The results of the survey are presented and discussed.

The exchangeable splenic platelet pool studied with epinephrine infusion in idiopathic thrombocytopenic purpura and in patients with splenomegaly.

Summary. The exchangeable splenic platelet pool (ESPP) was studied with epinephrine infusion and platelet labelling with 51Cr in five healthy students, 10 patients with idiopathic thrombocytopenic purpura (ITP) and 10 patients with splenomegaly. Five of the ITP‐patients were studied after splenectomy. Platelet recovery of infused labelled platelets was calculated in all subjects and also in nine healthy volunteers who had been splenectomized for traumatic rupture of the spleen. Spleen size was determined by gamma camera scintigraphy. It was shown that the spleen is the only site of an exchangeable platelet pool in ITP and that this pool was of the same size in ITP‐patients as in the normal controls, viz ∼30% of the total body platelet mass.In patients with splenomegaly the ESPP was larger than that in controls and ITP‐patients. A highly significant correlation was found between the ESPP and the spleen volume. In splenectomized and in non‐splenectomized ITP‐patients platelet recovery was significantly less than in their respective control groups, indicating that a proportion of the labelled platelets was immediately removed from the circulation after infusion into an ITP recipient and that the recovery of labelled platelets cannot be used as a measure of the ESPP in ITP.It is suggested that the early destruction of platelets may be due to slight damage to the platelets during the labelling procedure. These damaged platelets can survive in a normal recipient, but are destroyed when infused into the‘milieu’ of an ITP‐patient.

Strontium-87m and the gamma camera in the study of bone metastases from carcinoma of the prostate.

Summary Bone-seeking isotopes can identify the site of osseous lesions in carcinoma of the prostate before radiography. The use of strontium-87m and the role of gamma camera scintigraphy in a series of 71 cases of carcinoma of the prostate is discussed. The value of strontium-87m scintigraphy is seen not only in its ability to detect some lesions earlier than radiological methods, but also as a parallel investigation which enhances overall diagnostic reliability. Repeated investigations are capable of providing some additional indications of the patient's response to treatment. The limitations of the scintigraphic method in repeated examinations are discussed.

Gamma-camera scintigraphy after kidney transplantation.

Gamma-camera scintigraphy with a 99Tcm-Fe-ascorbic acid complex was used to study the graft in the course of 37 kidney transplantations. In a 2-year period, 167 investigations were made. To describe the pictures, a simple code was elaborated. Scintigraphy, whether routinely performed, or in emergency cases, contributed to early recognition and differential diagnosis of complications. Information valuable for appropriate management of the patient was often obtained. The frequency of more demanding diagnostic procedures was reduced.