Nucl Med Mol Imaging.  2012 Dec;46(4):254-260.

Validation of Simple Quantification Methods for 18F-FP-CIT PET Using Automatic Delineation of Volumes of Interest Based on Statistical Probabilistic Anatomical Mapping and Isocontour Margin Setting

• Kim YI
• Im HJ
• Paeng JC
• Lee JS
• Eo JS
• Kim DH
• Kim EE
• Kang KW
• Chung JK
• Lee DS

Abstract

PURPOSE
18F-FP-CIT positron emission tomography (PET) is an effective imaging for dopamine transporters. In usual clinical practice, 18F-FP-CIT PET is analyzed visually or quantified using manual delineation of a volume of interest (VOI) for the striatum. In this study, we suggested and validated two simple quantitative methods based on automatic VOI delineation using statistical probabilistic anatomical mapping (SPAM) and isocontour margin setting.
METHODS
Seventy-five 18F-FP-CIT PET images acquired in routine clinical practice were used for this study. A study-specific image template was made and the subject images were normalized to the template. Afterwards, uptakes in the striatal regions and cerebellum were quantified using probabilistic VOI based on SPAM. A quantitative parameter, QSPAM, was calculated to simulate binding potential. Additionally, the functional volume of each striatal region and its uptake were measured in automatically delineated VOI using isocontour margin setting. Uptake-volume product (QUVP) was calculated for each striatal region. QSPAM and QUVP were compared with visual grading and the influence of cerebral atrophy on the measurements was tested.
RESULTS
Image analyses were successful in all the cases. Both the QSPAM and QUVP were significantly different according to visual grading (P<0.001). The agreements of QUVP or QSPAM with visual grading were slight to fair for the caudate nucleus (kappa=0.421 and 0.291, respectively) and good to perfect to the putamen (kappa=0.663 and 0.607, respectively). Also, QSPAM and QUVP had a significant correlation with each other (P<0.001). Cerebral atrophy made a significant difference in QSPAM and QUVP of the caudate nuclei regions with decreased 18F-FP-CIT uptake.
CONCLUSION
Simple quantitative measurements of QSPAM and QUVP showed acceptable agreement with visual grading. Although QSPAM in some group may be influenced by cerebral atrophy, these simple methods are expected to be effective in the quantitative analysis of 18F-FP-CIT PET in usual clinical practice.

Keyword

18F-FP-CIT PET; PET; Statistical probabilistic anatomical mapping; Volume of interest; Validation

MeSH Terms

Atrophy
Caudate Nucleus
Cerebellum
Dopamine
Positron-Emission Tomography
Putamen
Dopamine