6. Gamma camera, SPECT, PET.

Nuclear medicine

a medical speciality involving the application of radioactive substances in the diagnosis and treatment of disease

gamma camera

can be used to detect the two-dimensional projection of the radiation that accompanies the decay of radiopharmaceuticals injected into the human body.

Collimator

A radiation absorbing lead layer with many tiny holes

Scintillation detectors

respond to gamma photon radiation with visible photon emission.
the magnitude of the light impulse is proportional to the energy used to induce ionization, and the number of impulses is proportional to the activity of the preparation

Photomultiplier Tube

The generated visible light photons are converted into an electric signal by photomultipliers.

Scintigrams

Two-dimensional projection images

Static scintigrams

summation of images of a long exposure

Dynamic scintigrams

series of snapshots recording a process

Single Photon Emission Computed Tomography (SPECT)

performed by using a gamma camera to acquire multiple 2D images from multiple a 3D angles.

A computer is then used to apply a tomographic reconstruction algorithm to the multiple projections, yielding a 3d data set. The technique needs delivery of gamma emitting radioisotope into the patient via injection.

Positron Emission Tomography (PET)

a computed tomography technique used to study the distribution of positron (β+ particle)-emitting isotope-labelled marker molecules that are injected into the body. It is a three-dimensional imaging technique

Image Fusion Techniques

combine morphological data from CT or MRI scans with functional information from a PETcamera. It superimposes the two images on each other