RT Journal Article SR Electronic T1 Three phase bone scan in patients with chronic foot pain, can we exclude phase I? JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP P961 OP P961 VO 64 IS supplement 1 A1 Aduraibi, Alaa A1 Dudek, Alexandra A1 BIN ESSA, NOORA A1 Lilburn, David A1 PRIFTAKIS, DIMITRIOS A1 WAN, SIMON A1 BOMANJI, JAMSHED YR 2023 UL http://jnm.snmjournals.org/content/64/supplement_1/P961.abstract AB P961 Introduction: Three-phase bone scintigraphy with SPECT/CT is an established and commonly used imaging method to establish aetiology of chronic foot pain. There remains controversy regarding the standard three-phase bone scintigraphy imaging protocol with limited published evidence. In this study, we assessed Phase I (flow phase) images and its correlation with findings from Phase II (blood pool) images in patients with foot pain undergoing 99mTc-HDP Three-phase bone scan.Methods: This is retrospective cohort study between 2020 -2021, 57 consecutive participants who had three-phase bone scan with SPECT CT where evaluated. Finding of different phases were classified as positive or negative by three experienced nuclear medicine physicians and correlated with clinical outcome. Agreement rates between phase I and phase II images were calculated.Results: Of the 57 patients (median age 51yrs, range 14-81yrs), 56.1% were females. 37 (64.9 %) had positive phase I and phase II scans. 9 patients had negative phase I but positive phase II scan, attributed to reactive post-surgical changes. The agreement rate of phase I to phase II was 84.2%. Anatomic foot region (P = 0.98), and referral indication for scan (P = 0.72) were not significantly associated to the agreement rate.Conclusions: In a three-phase bone scan with SPECT/CT done for chronic foot pain evaluation, the flow phase (phase I) does not commonly add further information over phase II scan, and thus may be potentially omitted.