Applying Pix2pix to Translate Hyperemia in Blood Pool Image into Corresponding Increased Bone Uptake in Delayed Image in Three-Phase Bone Scintigraphy

다국어 초록 (Multilingual Abstract)

Purpose Delayed images may not be acquired due to severe pain, drowsiness, or worsening vital signs while waiting afterblood pool imaging in three-phase bone scintigraphy. If the hyperemia in the blood pool image contains information fromwhich increased uptake on the delayed images can be inferred, the generative adversarial network (GAN) can generate theincreased uptake from the hyperemia. We attempted to apply pix2pix, a type of conditional GAN, to transform hyperemiainto increased bone uptake.
Methods We enrolled 1464 patients who underwent three-phase bone scintigraphy for inflammatory arthritis, osteomyelitis,complex regional pain syndrome (CRPS), cellulitis, and recent bone injury. Blood pool images were acquired 10 minafter intravenous injection of Tc-99 m hydroxymethylene diphosphonate, and delayed bone images were obtained after 3 h.
The model was based on the open-source code of the pix2pix model with perceptual loss. Increased uptake in the delayedimages generated by the model was evaluated using lesion-based analysis by a nuclear radiologist in areas consistent withhyperemia in the blood pool images.
Results The model showed sensitivities of 77.8% and 87.5% for inflammatory arthritis and CRPS, respectively. In osteomyelitisand cellulitis, their sensitivities of about 44% were observed. However, in cases of recent bone injury, the sensitivitywas only 6.3% in areas consistent with focal hyperemia.
Conclusion The model based on pix2pix generated increased uptake in delayed images matching the hyperemia in the bloodpool image in inflammatory arthritis and CRPS.