In the present invention, we solve the problem of facilitating blood pool measurements accessible to patients or researchers by using 18FDG for the in vitro intracellular labeling of RBCs (Red blood cells). 18FDG tracer is available worldwide and as a glucose analogue it may be incorporated by the erythrocytes and trapped intracellularly. In this sense, a blood sample (such as whole peripheral blood) can be extracted or isolated from a subject or from another subject with blood compatibility. The extracted or isolated blood can be then incubated in contact with 18FDG for a period of time and later be reinjected into the patient. Labeling of RBCs with 18FDG will expand the use of the PET technique to blood pool imaging with the consequent improvement in the field of clinical diagnosis.
