
Scintigraphy
is a technique where radioisotope is injected intravenously.
A gamma camera is used to record uptake of the nucleotide in the tissues.
It is particularly useful diagnostically to localize an area of inflammation
in the musculoskeletal system.
The
radioisotope introduced into the body reaches the target organ and emits
gamma radiation ready to be captured by the gamma camera. This apparatus
contains crystals of sodium iodide, which react to the gamma rays producing
scintillation. Scintillation counters placed around the crystals transform
the flashes into electronic signals. The signals are transmitted to
a computer for analysis and elaboration of the image of the investigated
organ.
The
most common radioisotope used to image bones is technetium-99m.
The pharmaceutical product we used is PYROSCINT - TM. It is a sterile
and apyretic substance in form of dehydrated powder, stored in nitric
atmosphere.
After reconstruction with pertechnetate (Tc- 99m) in physiological solution,
a diagnostical agent is obtained, to be administered intravenously.
Technetium pyrophosphate (Tc-99m) is used to produce images of skeleton
and makes possible the examination of osteogenetic areas. The intravenous
injection of tin pyrophosphate followed by the intravenous injection
of pertechnetate (Tc-99m) enables us to mark the red blood cells with
technetium 99m.
Technetium
99m turns into a stable form - Technetium 99 - through isomeric transition
in half life of 6.02 hours.
The
basic characteristics of radioactive emissions of Technetium-99m:
- major radiation: gamma rays
- medium disintegration rate: 89,3%
- medium energy (MeV): 0.140