Purpose Acute cellular rejection (ACR) is one of the most common complications in the first year after heart transplantation (HT). Endomyocardial biopsy (EMB) is the gold standard for ACR diagnosis, although it is neither very accurate nor reproducible, with false negative and false positive results reported. This pilot study aimed to determine the feasibility of the dynamic computed tomography perfusion (CTP) as an additional, non-invasive tool for rejection diagnosis after HT. Methods The study group included 12 HT recipients and 20 controls who underwent CTP. ACR were detected on EMBs (ISHLT 2004). The results of CTP was represented as myocardial blood flow (MBF) and myocardial blood volume (MBV). Results Of 12 patients, 8 had ACR in EMB. CTP revealed either normal myocardium (Fig 1B) or irregular hypoperfused areas (Fig. 1A), localized mainly in the midwall layer of myocardium, which we called midwall patchy pattern (MPP). Within HT patients the number of segments with MPP correlated with the number of EMBs GRADE ≥1R (p 1 segment with MPP correlated significantly with GRADE ≥1R with 100% sensitivity and 96% specificity (AUC=0.974;p Conclusion Dynamic CTP perfusion abnormalities in HT recipients may be correlated with cardiac allograft rejection, comprising potential non-invasive tissue biomarker for rejection. Our pilot study pioneer findings need confirmation in larger patient population. The study is funded by the Institute of Cardiology - grant 2.3/V/18 and by the National Science Centre, Poland - grant 2015/19/B/NZ5/03502