Objective To investigate the myocardial perfusion abnormalities in patients with isolated left ventricular noncompaction (ILVNC) and analyze the correlation between MPI and MRI.Methods Nineteen patients (14 males,5 females,age range:15-76 years) with ILVNC diagnosed by cardiac MRI were recruited.All patients underwent 99Tcm-MIBI MPI.Both MPI and cardiac MRI were analyzed using a 17-segment model.The thickness ratio of the non-compacted to compacted layers of myocardium (NC/C) was calculated,and segments with NC/C＞2.3 were considered as noncompaction.The incidences of delayed enhancement (DE) and myocardial perfusion abnormalities in non-compacted segments and compacted segments were calculated.x2 test was used for categorical data.The Pearson and Spearman correlation coefficient were used to assess the relationship between the numbers of myocardial segments with myocardial perfusion abnormalities/noncompaction/DE and lgLVEF.Results Of 19 patients,myocardial perfusion abnormality was found in 16 (84.2％) patients.The incidences of perfusion abnormality were 33.6％ (36/107) in non-compacted segments and 31.9％ (69/216) in compacted segments,respectively (x2=0.09,P＞0.05).There were 31 segments with DE.The incidences of DE were 5.6％ (6/107) in non-compacted segments and 11.6％ (25/216) in compacted segments,respectively (x2 =2.94,P＞0.05).The incidence of reduced perfusion was higher in segments with DE than those in segments without DE (54.8％ (17/31) vs 30.1％ (88/292) ; x2 =7.80,P＜0.01).The lgLVEF and the numbers of myocardial segments with noncompaction/DE/myocardial perfusion abnormalities were not correlated(r=-0.35,0.15,-0.34,all P＞0.05).Conclusion Most patients with ILVNC have myocardial perfusion abnormality,which can be observed both in non-compacted and compacted myocardium.Further research is required to elucidate the role of myocardial perfusion abnormality in ILVNC.