Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.


1. a means or agent by which certain substances or structures can be identified or followed, as a radioactive tracer.
2. a mechanical device by which the outline of an object or the direction and extent of movement of a part may be graphically recorded; see also tracing.
3. a dissecting instrument for isolating vessels and nerves.
radioactive tracer a radioactive isotope replacing a stable chemical element in a compound (said to be radiolabeled) and so able to be followed or tracked through one or more reactions or systems by means of a radiation detector; used especially for such a compound that is introduced into the body for study of the compound's metabolism, distribution, and passage through the body.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


A radionuclide or radiolabeled chemical; a radioactive tracer.
Farlex Partner Medical Dictionary © Farlex 2012
References in periodicals archive ?
Caption: Figure 4: Macroscopic detection of macrocalcifications induced by direct injection of rhBMP-2 into MDA-MB231 syngeneic tumor: both CT imaging and PET imaging indicate that, in comparison to systemic, nonsystemic injection of rhBMP-2 into tumor induced microcalcification in breast tumor was dose dependent, and the uptake of radiotracer ([sup.18]F-NaF) was significantly higher (left tumors in (a)-(c)) than the IP injection of rhBMP-2.
The difference between the clinically observed results and CUI ranking showed that the evaluation of the clinical usefulness of tau radiotracer based on binding to a single target could not reflect the actual in vivo binding in subjects.
PET reconstruction algorithms aim at obtaining an image of the patient, given the radiotracer distribution in the body.
After that, complete radiotracer is prepared for intravenous injection.
Caption: Figure 2: Anterior planar nuclear images of the thorax (upper images) and abdomen (lower images) obtained after radiotracer administration with [sup.99m]Technetium-labeled albumin into the peritoneal cavity.
(d) Anterior and posterior planar views from a postablation I-131 WBS show expected radiotracer uptake in the neck as well as an incidental focus of intense activity in the left lower thorax (arrow).
This radiotracer has been enrolled in a phase 3 trial.
Linear uptake in the posteromedial distal tibial aspects indicated medial tibial stress syndrome or shin splints and radiotracer accumulation at the insertion sites of major lower limb muscles was labeled as activity induced enthesopathy.
The IMAkinib project includes several programs, the most advanced being the development of an EGFR kinase-targeting radiotracer. Mutations activating this kinase are responsible for non-small-cell lung adenocarcinoma, which accounts for 15% of lung cancers and affects almost 6,000 patients2 each year in France.
Results showed that after follow-up, patients' SPECT scans revealed substantial decreases in radiotracer binding to the dopamine transport system in the nigrostriatal regions of the brain.
99mTc-DMSA scan revealed an inhomogeneous distribution of radiotracer in renal parenchyma, which was lower in the upper-medial part of the right kidney.
A 123-I Meta-Iodobenzylguanidine (MIBG) scan was arranged demonstrating avid uptake of radiotracer to the right retroperitoneal mass only (Fig.