Technical issues
- Injection site will cause high radiotracer activity
- Extravasation of injection causes uptake in lymph nodes
Equipment malfunction
- Malfunction of gamma camera system
- Photomultiplier tube (PMT) failure
- Cracked or broken scintillation crystal
- Correction matrix failure
- Cracked crystal
- Differences in detector sensitivity
Patient related
- Attenuation can be caused by:
- Objects worn by the patient e.g. belt buckles
- Breast attenuation especially breast prosthesis
- Diaphragmatic attenuation: especially in patients that are obese, have ascites, on dialysis
- Patient motion causes misalignment of reconstructed images
- Urinary contamination
Physiological uptake
- Head and neck
- Brain cortex
- Waldeyer’s ring
- Salivary glands
- Extra-ocular muscles
- Larynx in excessive talking
- Muscles
- Stress-induced tension – trapezius and paraspinal muscles
- Hyperventilation – diaphragm
- Insulin – skeletal muscle
- Vigorous exercise
- GIT / GUT
- Caecum / right colon more glucose avid
- Renal collecting system, ureters and bladder
- Uterine uptake in menstruation
- Miscellaneous
- Lactating breasts
- Myocardial uptake post-prandially
- Brown fat
- Thymus in children
SPECT and PET/CT specific
- Centre-of-rotation error
- In SPECT, if presumed centre-of-rotation doesn’t match actual axis of rotation back-projection will be affected
- Misregistration between radionuclide and CT images
- All CT related artefacts
- Truncation
- SPECT field of view is larger than CT field of view
- No CT data available for attenuation correction of the SPECT images
Written by radiologists, for radiologists with plenty of easy-to-follow diagrams to explain complicated concepts. An excellent resource for radiology physics revision.