[Indications and instructions to patients for a positron emission tomography-PET scan. The importance of the hybridic PET/CT-computerised tomography scan and which specialty should be responsible for its function].

Indications and instructions to patients for performing a positron emission tomography - PET scan are mentioned. Although PET camera was developed in 1970 its clinical indications were established in about 1998. The hybridic PET/CT- computerized tomography scanner appeared in 2001 and its clinical indications are still under discussion. These discussions refer to both the use of PET/CT as an acquisition correction and anatomic localization device for PET images (AC/A) and to its use as a diagnostic CT scan (dCT). Most of the patients submitted for a PET scan have already done a dCT scan. This was the case in 286 out of the first 300 patients referred to "Evangelismos" hospital in Athens for a PET scan. These two scans can be matched electronically. Extra cost, space, personnel and radiation absorption dose especially in children, are additional factors to be considered in using the PET/CT scanner. The specialty of Nuclear Medicine is now based on the PET camera, its best part and main equipment for molecular imaging. It is very much easier and faster for a Nuclear Medicine physician who routinely reports tomographic PET and SPET images, to be familiar with the CT images than for a Radiologist to get to "know how" about the PET camera and the whole Nuclear Medicine Department. Nuclear Medicine is about open radiation sources, molecular imaging, specific radio-pharmacology, radiobiology, radiation protection etc, while on the other hand in some countries, Nuclear Physicians have already spent, as part of their official training, six months in a Radiology Department whose function is considered to be at least 25% about the CT scanner. We come to the conclusion that the PET/CT scanner should be under the responsibility of the Nuclear Medicine Department and the Radiologist should act as an advisor.