title: Study of an image-derived SUV and a modified SUV using mouse FDG-PET.
abstract: BACKGROUND
  Standard uptake value (SUV) is calculated without consideration of the differences in plasma 2-deoxy-2-[18F]fluoro-D-glucose (FDG) clearance. Its variability can be affected by changes of the amount of excreted FDG by renal function. Moreover, the estimation of SUV is quite sensitive to errors in the measurements of body weight and injected dose. This study aims to develop an image-based method to obtain an image-derived SUV (iSUV) and a modified SUV (mSUV) to overcome these problems.
  
  
  METHODS
  Thirty-one tumor-planted SCID mice were scanned in micro-positron emission tomography (PET) at ∼60 min post FDG injection and then scanned in micro-computed tomographic (CT). Using image-based method, the body weight and injected dose were derived from the microPET/CT images to calculate iSUV. The volumes and the total activities of FDG within the bladder and the whole-body were also obtained to calculate mSUV. For the selected targets, the iSUVs and mSUVs were compared against their corresponding SUVs.
  
  
  RESULTS
  Compared with SUV factor (injected dose/body weight), iSUV factor had an average percentage error of -0.7%. The linear regressions between SUV and iSUV had a slope of 0.99 with correlation coefficient of 0.95. Compared with SUV and iSUV, coefficient of variation of mSUV decreased while the tumor-to-background separation of mSUV increased.
  
  
  CONCLUSIONS
  Using this image-based method, the iSUV can replace SUV when the actual measurements were missing or unreliable. The mSUV can reduce the inter-subject variability and enhance the tumor-to-background separation in mouse FDG-PET studies.
authors.affiliation: Department of Electronic Information Engineering, the Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. zhengxj@eie.polyu.edu.hk
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Zheng
authors.forename: Chin-Lung
authors.initials: CL
authors.lastname: Yu
authors.forename: Wei
authors.initials: W
authors.lastname: Sha
authors.forename: Caius
authors.initials: C
authors.lastname: Radu
authors.forename: Sung-Cheng
authors.initials: SC
authors.lastname: Huang
authors.forename: Dagan
authors.initials: D
authors.lastname: Feng
mesh_terms: D000818:Animals; D001692:Biological Transport; D003937:Diagnosis, Differential; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D051379:Mice; D049268:Positron-Emission Tomography / Q000379:methods*
chemical_list: D019788:Fluorodeoxyglucose F18