title: Ruthenium-97 DTPA: a new radiopharmaceutical for cisternography.
abstract: Ruthenium-97 DTPA (diethylenetriamine penta-acetic acid) was evaluated for its possible use as a cerebrospinal fluid imaging agent. Ru-97 has favorable physical properties that are highly suitable for imaging: decay by electron capture; gamma energy = 216 keV, 85%; T 1/2 = 2.9 days. Dogs were injected with 0.4 mCi Ru-97 DTPA or In-111 DTPA into the cisterna magna. The movement of the agents was monitored with a camera interfaced to a computer, or with a dual-probe system placed over the head and urinary bladder. In addition, blood and urine samples were collected at fixed intervals for 6 hr. High-quality images were obtained up to 48 hr after injection. The results show that the kinetics and excretion of Ru-97 DTPA are similar to those of In-111 DTPA. Radiation dose for identical activities is twice as high for In-111, in part because of greater abundance of the low-energy electron emission of In-111.
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging*; D002946:Cisterna Magna / Q000000981:diagnostic imaging*; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D005260:Female; D006849:Hydrocephalus / Q000000981:diagnostic imaging; D007204:Indium / Q000134:cerebrospinal fluid / Q000378:metabolism; D051379:Mice; D004369:Pentetic Acid / Q000134:cerebrospinal fluid / Q000378:metabolism; D011829:Radiation Dosage; D011868:Radioisotopes; D011877:Radionuclide Imaging; D012428:Ruthenium / Q000134:cerebrospinal fluid / Q000378:metabolism; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D011868:Radioisotopes; D007204:Indium; D004369:Pentetic Acid; D012428:Ruthenium