Detection and compensation of organ/lesion motion using 4D-PET/CT respiratory gated acquisition techniques.
OBJECTIVE
To describe the degradation effects produced by respiratory organ and lesion motion on PET/CT images and to define the role of respiratory gated (RG) 4D-PET/CT techniques to compensate for such effects.


METHODS
Based on the literature and on our own experience, technical recommendations and clinical indications for the use of RG 4D PET/CT have been outlined.


RESULTS
RG 4D-PET/CT techniques require a state of the art PET/CT scanner, a respiratory monitoring system and dedicated acquisition and processing protocols. Patient training is particularly important to obtain a regular breathing pattern. An adequate number of phases has to be selected to balance motion compensation and statistical noise. RG 4D PET/CT motion free images may be clinically useful for tumour tissue characterization, monitoring patient treatment and target definition in radiation therapy planning.


CONCLUSIONS
RG 4D PET/CT is a valuable tool to improve image quality and quantitative accuracy and to assess and measure organ and lesion motion for radiotherapy planning.
Bettinardi
Valentino
V
Nuclear Medicine, San Raffaele Scientific Institute, Milan, Italy. valentino.bettinardi@hsr.it
Picchio
Maria
M
Di Muzio
Nadia
N
Gianolli
Luigi
L
Gilardi
Maria Carla
MC
Messa
Cristina
C
D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006801:Humans; D008991:Monitoring, Physiologic; D009369:Neoplasms / Q000532:radiotherapy*; D049268:Positron-Emission Tomography / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted; D012119:Respiration