The Importance of the SPECT/СT in the Diagnosis of Asymptomatic Myocardial Ischemia for a Specific Patient

Purpose: To demonstrate a clinical observation in which the diagnosis of ischemic heart disease with vasospastic coronary microvascular dysfunction was established mainly using ^99mTc-MIBI SPECT/CT.

Material and methods: In patient G.D.S., 39 years old by profession of an electric locomotive driver, who did not present any health complaints, oblique ST segment depression was registered during Holter monitoring on ECG. The following methods were used to establish the diagnosis: echocardiography, X-ray computed tomography (CT) to assess coronary artery calcinosis, single-photon emission computed tomography (SPECT) with ^99mTc-technetril to assess myocardial perfusion and contractile function on hybrid SPECT/CT system SymbiaT16 (Siemens), coronary angiography (CAG).

Results: Only at examination on hybrid tomograph at rest and during physical activity (bicycle ergometer 125 W ‒ 5 minutes), sequentially applying in one diagnostic procedure two studies (CT and SPECT with ^99mTc-MIBI) 26 study parameters were obtained (at CT ‒ 4 parameters evaluating coronary artery calcinosis, at SPECT ‒ 11 parameters of perfusion and 11 parameters of myocardial function). The absence of coronary artery calcinosis was revealed (which was confirmed by CAG), and the study at rest and during exercise revealed a decrease in perfusion (hence myocardial blood flow) in the apical-lateral (16-th segment); apex (17), apical-anterior (13), anterior-medial (7), anterolateral middle (12); irreversibility of perfusion defect, total and ischemic perfusion deficit.

Conclusion: A clinical observation is demonstrated in which, only the use of hybrid SPECT/CT system allowed to establish the absence of coronary artery calcinosis and the decrease of perfusion (hence myocardial blood flow), irreversibility of perfusion defect, total and ischemic perfusion deficit (all listed indices had penultimate moderately pronounced degree).