Isaac C. Reese

Placental Localization by Scanning with Indium 113m

WITH THE recent development of new radiopharmaceuticals and better instrumentation there has been increased interest in the use of radionuclides to localize the placenta. One promising radionuclide, indium 113m, the hundred-minute half-life metastable daughter radionuelide of tin 113, has a pure 390 keV gamma emission without associated particulate emission. It may easily be manipulated pharmacologically. When injected intravenouslyat a proper pH it binds tightly to the beta globulin, transferrin, and remains in the blood pool (1). Since the parent radionuc1ide, tin, has such a long half-life, a tin 113-indium 113m generator may be kept for several months to provide the indium 113m. This is convenient from the standpoint of availability and economic feasibility. Since September 1967 we have used indium 113m as indium chloride stabilized with gelatin and made isotonic with sodium chloride for placental localization. Methods Patients with third-trimester bleeding suspected of having placenta previa were sca...

Indium 113m for scanning bone and kidney.

Strontium 85 as strontium nitrate is at present used to detect occult neoplasm of bone (1). Because of its long physical and biological half-time the amount of radioactivity given to the patient must be limited in order to keep the dose to the patient at an acceptable minimum level. The low photon yield makes the scanning procedure long and tedious, often exhausting an already ill patient and imposing limitations on the areas that can be scanned. The recent development of gallium citrate using the short-lived positron emitter, gallium 68, as a bone-scanning agent led us to examine indium 113m as a possible agent for bone and kidney scanning. The group at Oak Ridge Institute of Nuclear Studies found that addition of carrier gallium prevents binding of the radioactive gallium by the beta globulin, transferrin, and gives gallium citrate bone-seeking properties similar to calcium, strontium, and fluoride (2–4). Since indium lies in the same group, III B, as gallium and because initial studies suggest that it ...

Pericardial and mediastinal involvement from bronchogenic carcinoma demonstrated by Tl-201 imaging.

Tl-201 chloride is one of the unique radiopharmaceuticals that can be used for myocardial perfusion study as well as for tumor imaging. This report demonstrates the value of this agent in detecting mediastinal involvement and malignant pericardial effusion from poorly differentiated squamous cell carcinoma of the lung on the same study.

LUNG/HEART RATIO TC99m ALBUMIN STUDIES TO SEPARATE PULMONARY EDEHA DUE TO PRESSURE/VOLUME OVERLOAD FROM THAT DUE TO DAMAGED CAPILLARIES

The hypothesis tested was that edema resulting from pulmonary capillary damage is accompanied by an increased net leakage of molecules such as albumin from the vascular space into the lung, whereas edema resulting primarily from increased venous pressure is not. Tc99m albumin was injected intravenously in three groups of patients: normal, cardiac failure, and adult respiratory distress syndrome (ARDS). One minute of data from an anterior view of the chest was obtained at 20 minutes and 3 hours following injection of 20mCi. A lung heart ratio (L/H) was calculated placing a box region of interest over the right mid lung field and the middle of the cardiac silhouette. In absolute increase of less than 10% between L/H1 (20 min) and L/H2 13 hrs) included all normal patients. All but 2 of the 18 patients with heart failure or volume overload edema had a L/H ratio which increased less 10%. Patients with ARDS showed a spectrum of L/H ratio changes from less than 10% in all 6 with narcotic overdose to an increased ratio in 3/10 with pneumonia, 2 of 2 with seizures, one each with blood transfusion reaction, sickle cell disease, eclampsia and 1 of 2 with tuberculosis. Using a ratio change corrects for geometric factors, chest wall uptake, variable blood clearance rates and label loss. This simple procedure, adaptable to the bedside, clearly distinguishes a volume or pressure overload group showing no L/H change over time, from those with other causes of pulmonary edema. It suggests that ARDS contains a wide spectrum of capillary changes.