An applicable method for PET/CT image quality assessment and comparison among three PET/CT systems with similar physical performance in cancer patients.

Purpose: This research proposes a method with specific procedure guideline for clinical PET/CT image quality assessment according to physicians' behavior of image interpretation and explore the relationship between image quality and image systems with similar physical performance.

Methods: Clinical PET/CT were divided according to body location: brain, chest, abdomen and pelvic cavity. We explored the lesions and suspicious regions where radiologists concerned most through eye-tracker and behavior observation study to generate an assessment checklist. Fifty-five patients who were statistically consistent in age, weight and height were studied. Thirty-seven were scanned with an experimental scanner A and control systems B or C because their clinical pathways required PET/CT examinations at short intervals, the other 18 were scanned with scanners A and C. The grade of every system's PET, CT and PET/CT image performance on the four parts was calculated by subtraction of mean value and variance between experimental and control systems.

Results: The scoring checklist was set for PET, CT and PET/CT images in four parts respectively, and a standard procedure guideline was formulated for assessment. Using assessment criteria, the statistical results objectively reflected certain systems' superiority on certain modalities and certain parts of the body.

Conclusion: Our criteria for clinical PET/CT image quality assessment and comparison were efficient.