Why am I referred for a Nuclear Medicine exam, what does it entail, what are its advantages over other techniques, and does it necessarily mean I am seriously ill? The answers to your questions…
by Blandine Rolea, Guerbet
There are many reasons to be referred for a Nuclear Medicine examination. Basically, there are two modalities under the term Nuclear Medicine, namely SPECT and PET.
The main advantage of a Nuclear Medicine examination is the possibility to obtain excellent and unique information about the of the examined organ’s function.
It offers good complementarity beside X-ray and MRI modalities, which display better anatomical images (spatial resolution).
More precisely, in this context, functional imaging means that we can get information on the metabolism of an organ or a system. This way, a dysfunction (hyper- or hypo- metabolism) offers information not otherwise observed on morphological images, leads to more precise characterization of the tissues and enables differentiation between benign and malignant lesions.
This can be applied to many systems such as cardiovascular, musculoskeletal, central nervous, thyroid and endocrine glands.
In Nuclear Medicine, only a small amount of active substance (contrast media) is injected to the patient, it is called a "tracer" which is a radio-active molecule selectively fixed by the explored organ: radiation is thus limited.
In case of cancer or inflammatory processes, the signal is modified according to hypermetabolism, giving information on the localisation and activity of the organs and therefore enabling the physician to adapt the therapeutic treatment accordingly.
On another hand, a low product fixation in the heart for example gives precise indications on a possible perfusion defect, which can be the sign of infarct.
This modality can be combined with CT-scanning in order to obtain both functional and morphological data during the same examination.
If Nuclear Medicine is mostly used for diagnostic purposes, it can also be used in therapeutic applications. It is for example the case with the treatment of hyperthyroidism.
In conclusion, Nuclear Medicine does not mean you suffer from a fatal disease, it means obtaining complementary information in addition to CT-Scan or MRI: namely, functional information.