the most important developments in this field allow the clinical use of radioisotopes with extremely short lifetimes combined with a very low radiation exposure , imaging of tumours by new radioactive labelled tumour-markers , the measurement of heart functions and blood flow through the use of computerized gammacameras with digital imaging processing capabilities and the three-dimensional imaging of radioactive tracers within the body .
C0034595
radioisotopes
C0034551
radioactive tracers