Preliminary Study Of Myocardial Perfusion Defects In Ischemic Heart Disease Patients Using Spectral CT Imaging

Objective: To evaluate the capability and application value of spectral CT imagingin diagnosing Ischemic heart disease.Methods: Fifty consecutive patients with cardiodynia were prospectively enrolledto undergo enhanced spectral CT imaging (Discovery CT750HD, GE healthcare).Iodine-base material decomposition images were obtained for the arterial phase （The tubevoltage of120kV, a tube current of automatically mA,64x0.625detector, as a512x512matrix, the the rack speed is0.35s/r all redevelopment manner the Asir40%.）and1-miutedelay phase. According to the result of ECG and CCTA, the50cases were divided intothree group: group A (with normal myocardium), group B (with myocardial ischemia),and group C (with myocardial infarction). Iodine density (ID) in the area of left andanterior descending (LAD) branch supplying myocardium was measured on theiodine-base images for each patient. The iodine density values were further normalized tothat of the thoracic aorta to obtain normalized iodine density (NID) for myocardium.Results: In this study there were20patients (group A) with normal myocardium,18patients (group B) with myocardial ischemia, and12patients (group C) with infarction.The ID for group A was statistically higher than group C (18.90±2.15vs.13.50±3.73)(P<0.05). ID for group B was also statistically higher than group C (19.11±2.68vs.13.50±3.73)(P<0.05). But there was no statistical difference between group A and groupB(p>0.05). The NID for group A was statistically higher than group B (0.57±0.06vs.0.47±0.05)(P<0.05). NID for group A was also statistically higher than group C (0.57±0.06vs.0.40±0.09)(P<0.05). But there was no statistical difference between group B and group C (p>0.05). It isn’t significant correlation between of coronary artery stenosisand myocardial iodine content.Conclusion: Spectral CT imaging with iodine-based material decompositionimage provided a new method to detect myocardial ischemia or infarction from the normalmyocardium, It’s no significant correlation between the degree of stenosis and myocardialischemia. Spectral CT first-pass perfusion of ischemic heart disease, can assess myocardialactivity can be identified by iodine content and standard iodine content of normalmyocardial ischemic myocardium and normal myocardium. Gemstone CT first-passmyocardial perfusion can be used in clinical diagnosis of ischemic heart disease, andqualitative and quantitative analysis and evaluation.10-minute delayed scan did not see amarked enhancement of the infarcted myocardium, delayed scanning time needs to beextended, in order to achieve the identification of ischemic myocardium and myocardialinfarction. Due to the lack of ECG-gated, still can not distinguish between systolic anddiastolic caused by iodine content differences due to period differences still can not beavoided.