World health organisation inter-laboratory comparison study in 12 countries on quality performance of nuclear medicine imaging devices

Abstract

Twelve countries participated in the WHO inter-comparison for which transmission CAP (College of American Pathologists) brain and CAP liver phantoms and emission London liver phantoms were used. A total of 157 imaging devices were tested. Overall results from the phantoms revealed a wide range of targets detected. For the CAP-phantoms target detectability dropped below 50% for target sizes less than 9 mm and below 60% for target contrast less than 0.84:1. On average one false positive and six false negative results were reported using CAP-brain phantoms and one false positive and one false negative result using CAP-liver phantoms. For the London liver phantoms containing the tissue equivalent rubber abdominal simulation the target of 1 cm was never visualised. Two targets in this phantom (2 cm and 2.5 cm) were correctly identified in 34% of studied and one of these targets in 52% of studies. Equivocal and false positive results were reported in 42%. The WHO inter-comparison demonstrated the need to establish new, or to improve the existing, quality control programmes.