CLINCIAL USE OF I$sup 125$ IN KIDNEY FUNCTION TESTING

Journal Article · Mon Jan 01 04:00:00 EST 1962 · Health Center J. (Columbus)

OSTI ID:4645557

Winter, C C; Myers, W G

BS>Ten compounds tagged with three different radioisotopes were evaluated for testing kidney function. Among the compounds tested, Urokon labeled with I/sup 131/ was found to be excreted too slowly; Diodrast-I/sup 131/ proved to have limited usefulness because it is also excreted by the liver; Miokon-I/sup 131/ and Renografin-I/sup 131/ were found to be excreted too slowly by the kidneys, as were DISA-I/sup 131/ (2,6-diiodosulfanilate with I/sup 131/) and EDTA-Cr/sup 51/ (chelated complex between ethylenediaminetetraacetate and Cr/ sup 51/). Hypaque-I/sup 131/ and Hippuran-I/sup 131/ currently are among the best test agents. Each is cleared rapidly from the blood by the kidneys alone. Hippuran (sodium ortho-iodohippurate) is the compound of choice because 3/4 of it clears into the urine of normal patients 30 min after it is injected. Cr/sup 51/ attached to EDTA, while having the desirable properties of lower radiation exposure, convenience, and economy, was found to be unsuitable for renal tests. In contrast, I/sup 125/ is useful in renography. It emits x rays and gamma rays with usable energies of 27.2 to 35.4 kev that have a broad beam half thickness in water and soft tissue of approximates 1 in. Its low-energy photons permit thin detector crystals to be used so that background counts are low and consequently dosages can be smaller. In addition, detectors can be much lighter and collimators less bulky than is necessary in the use of I/sup 131/ (whose emissions include a 364-kev gamma ray). A second renogram may be made immediately by covering the detector crystal with a 0.01-in. lead foil to absorb the soft I/sup 125/ photons and administering a compound labeled with I/sup 131/, for example, Hippuran-I/sup 131/. As an alternative, a spectrometer may be used to tune out I/sup 125/ photons in the presence of an emitter of higher energy photons. with detectors and circuitry that are best matched to exploit fully the superior physical properties of I/sup 125/. It reduces radiation exposure to the patient and affords a major simplification of equipment used in testing kidney function, and its longer shelf life of 60 days, compared with I/sup 131/ (8 days), reduces the cost of the test agent. (BBB)

• Research Organization: Ohio State Univ., columbus
• NSA Number: NSA-17-038713
• OSTI ID: 4645557
• Journal Information: Health Center J. (Columbus), Journal Name: Health Center J. (Columbus) Vol. Vol: 12
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BACKGROUND
BIOLOGY AND MEDICINE
COLLIMATORS
CRYSTAL COUNTERS
DECAY
DIAGNOSIS
DIODRAST
DRUGS
EDTA
EMISSION
FOILS
GAMMA RADIATION
HIPPURAN
HIPPURIC ACID
IODINE 125
IODINE 131
KIDNEYS
LABELLED COMPOUNDS
LEAD
LIVER
METABOLISM
OPTICAL SYSTEMS
PHOTONS
PHYSIOLOGY
RADIOGRAPHY
RADIOISOTOPES
SODIUM COMPOUNDS
SPECTROMETERS
STORAGE
TRACER TECHNIQUES
X RADIATION