Positron emission tomography - computed tomography (better known by its acronym PET-CT) is a medical imaging

Medical imaging

Medical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...

 device which combines in a single gantry

Gantry

Gantry may refer to:*Gantry crane, a crane having a hoist fitted in a trolley for parallel movement*Gantry , the frame which encloses and services a rocket at its launch pad*Gantry , an overhead assembly on which highway signs are posted...

 system both a Positron Emission Tomography

Positron emission tomography

Positron emission tomography is nuclear medicine imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide , which is introduced into the body on a...

 (PET) and an x-ray

X-ray

X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...

 Computed Tomography

Computed tomography

X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...

, so that images acquired from both devices can be taken sequentially, in the same session from the patient and combined into a single superposed (co-registered

Image registration

Image registration is the process of transforming different sets of data into one coordinate system. Data may be multiple photographs, data from different sensors, from different times, or from different viewpoints. It is used in computer vision, medical imaging, military automatic target...

) image. Thus, functional imaging

Functional imaging

Functional imaging , is a method of detecting or measuring changes in metabolism, blood flow, regional chemical composition, and absorption....

 obtained by PET, which depicts the spatial distribution of metabolic

Metabolism

Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...

 or biochemical

Biochemistry

Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...

 activity in the body can be more precisely aligned or correlated with anatomic imaging obtained by CT scanning.