Optimal dose of XXXX required for whole-body PET using an LSO PET camera.

@entity1 @entity5377 @entity419 @entity44139 @entity3
Reducing the acquisition time of whole-body @entity419 positron emission tomography ( @entity419 PET) (corrected for attenuation) is of major importance in clinical practice. With the introduction of @entity44139 (LSO), the acquisition time can be dramatically reduced, provided that @entity1 are injected with larger amounts of tracer and/or the system is operated in 3D mode. The aim of this study was to determine the optimal dose of @entity419 required in order to achieve good-to-excellent image quality when a "3-min emission, 2-min transmission/bed position" protocol is used for an LSO PET camera. A total of 218 consecutive whole-body @entity419 PET studies were evaluated retrospectively. After excluding @entity1 with liver @entity3 , hyperglycaemia and paravenous injections, the final study population consisted of 186 subjects (112 @entity1 , 74 @entity1 , age 59 +/- 15 years). @entity1 were injected with an activity of @entity419 ranging from 2.23 to 15.21 MBq/kg. Whole-body images corrected for attenuation (3 min emission, 2 min transmission/bed position) were acquired with an LSO PET camera (Ecat Accel, @entity5377 ) 60 min after tracer administration. @entity1 were positioned with their arms along the body. Image reconstruction was done iteratively and a post-reconstruction filter was applied. Image quality was scored visually by two independent observers using a five-point scoring scale (poor, reasonable, good, very good, excellent). In addition, the coefficient of variability (COV) was measured in a region of interest over the liver in order to quantify noise. Of the images obtained in 118 @entity1 injected with > or =8 MBq/kg @entity419 , 92% and 90% were classified as good, very good or excellent by observer 1 and observer 2, respectively. The COV averaged 10.63% +/- 3.19% for doses > or =8 MBq/kg and 16.46% +/- 5.14% for doses <8 MBq/kg. Administration of an @entity419 dose of > or =8 MBq/kg results in images of good to excellent quality in the vast majority of @entity1 when using an LSO PET camera and applying a 3-min emission, 2-min transmission/bed position acquisition protocol. At lower doses, a rapid decline in image quality and increasing noise are observed. Alternative protocols should be adopted in order to compensate for the loss in image quality when doses <8 MBq/kg are used.
