Diagnostic Imaging

​How are the Images taken?

The patient is asked to lie still on an imaging bed. The gamma camera or SPECT/CT camera is positioned above and below the area/s of interest. The camera detects the signals​ (gamma rays) from the radiation that is emitted from the patient's body. Images are obtained of the distribution within the body over a period of time. The scan may take between 10 and 120 minutes, depending on the type of study. The patient is required to lie still for the duration of the scan.

  • ​A Static image is one picture​ taken over a set time period.

  • Dynamic images are lots​ of continuous pictures which can be played back like a movie and used to measure t​​he clearance of a radiopharmaceutical from the organ of interest.  The camera remains set in one position for these scans.

  • For whole body scans, the imaging bed moves the patient past the detectors, imaging from head to toe.

  • For tomography (SPECT) the detectors move round the patient to form a 3D image. Sometimes SPECT i​s followed by a low dose CT scan (SPECT/CT); the two sets of images are then fused to enhance anatomical localisation.

The mai​n advantages of SPECT/CT are represented by:

  • Bett​er attenuation correction ie. correcting for patient size and contour.
  • Increased speci​ficity
  • Accurate localisation of abnormal uptake/disease and possible involvement of adjacent str​uctures eg. bone scans.
  • Aiding the ​planning of minimally invasive surgery as it assists in pre-surgical localisation eg. parathyroid imaging.



For information on specific Nuclear Medicine Procedures​

rounded corners top

Related Documents

rounded corners bottom
Page last reviewed: 10 March 2015