Validation of an electronic image reader training programme for interpretation of [(18)F]flutemetamol β-amyloid PET brain images

OBJECTIVES: An electronic training programme (ETP) was developed for interpretation of images during routine clinical use of the PET amyloid imaging agent [(18)F]flutemetamol injection (VIZAMYL). This study was carried out to validate the ETP. MATERIALS AND METHODS: Five nuclear medicine technologists (NMTs) and five readers previously inexperienced in amyloid image interpretation were required to self-train using the ETP and pass a test to participate. A total of 305 [(18)F]flutemetamol PET images were then tested as the validation set, following preassessment and reorientation (where required) by one of five NMTs. Next, a new set of readers blinded to clinical information independently assessed all 305 images. Images had been acquired in previous studies from patients representing the full spectrum of cognitive capacity. When available, a standard of truth determined by histopathology or clinical history was used to derive sensitivity and specificity for image interpretation from this validation set. Randomly selected images (n=29) were read in duplicate to measure intrareader reproducibility. Images were read first without, and subsequently with anatomic images, if available. RESULTS: All NMTs and all readers scored 100% on the qualifying test. The interpretation of 135 cases without anatomic image support resulted in sensitivity ranging from 84% to 94% (majority 94%, median 92%) and specificity ranging from 77% to 96% (majority 92%, median 81%). Inter-reader agreement was very high, with most κ scores more than 0.8. Intrareader reproducibility ranged from 93 to 100%. CONCLUSION: The self-guided ETP effectively trained new amyloid PET image readers to accurately and reproducibly interpret [(18)F]flutemetamol PET images.