Computed tomography (CT)-based myocardial perfusion imaging (CTP)has been widely recognized as a one-station solution for the imaging of myocardial ischemia-related diseases. This article reviews the clinical scanning protocols,analytical methods,and research advances of CTP in recent years and briefly discusses its limitations and future development.
Humans ; Myocardial Ischemia ; diagnostic imaging ; Myocardial Perfusion Imaging ; Myocardium ; Prospective Studies ; Tomography, X-Ray Computed

As one of the non-invasive imaging techniques, myocardial perfusion imaging provides a basis for the diagnosis of myocardial ischemia in coronary heart disease. Aiming at the bull-eye image in myocardial perfusion imaging, this paper proposed a branching structure, which included multi-layer transposed convolution up-sampling concatenate module and four-channel weighted channels attention module, and the output results of the branch structure were fused with the output results of trunk U-Net, to achieve accurate segmentation of the cardiac ischemia missing degree in myocardial perfusion bull-eye image. The experimental results show that the multi-layer transposed convolution up-sampling concatenate module realizes the fusion of different depth feature maps, and effectively reduces the interference of the severe sparse degree which is similar to the missing degree on the segmentation. Four-channel weighted attention module can further improve the ability to distinguish between the two similar degrees and the ability to learn edge details of the targets, and retain more abundant edge details features. The experimental data came from Tianjin Medical University General Hospital, Tianjin TEDA Hospital, Tianjin First Central Hospital and Third Central Hospital. The Jaccard scores in the self-built dataset was 5.00% higher than that of U-Net. The model presented in this paper is superior to other optimized models based on U-Net, and the subjective evaluation meets the accuracy requirements for clinical diagnosis.
Humans ; Image Processing, Computer-Assisted ; Ischemia ; Myocardial Ischemia/diagnostic imaging* ; Neural Networks, Computer ; Perfusion

Fatty Acids ; metabolism ; Humans ; Myocardial Ischemia ; diagnostic imaging ; metabolism ; Tomography, Emission-Computed, Single-Photon

BACKGROUNDSince the size of ischemic myocardium is closely related with both global and regional function of the myocardium, it is of great significance to measure the size of ischemic myocardium with non-invasive methods.

METHODSEleven mongrel dogs were subjected to occlusion of the left anterior descending coronary artery for acute ischemia. Strain rate imaging had M-mode of strain-rate (CAMM) curve pointed from the basal segment of the anterior wall to the basal segment of the inferior wall to detect the border of ischemia size. The strain rate (SR) defined the cut-off value of ischemic myocardium in a two-chamber apical view, and marked by the anterior and inferior wall on two-dimensional images respectively. Along the endocardium and epicardium, the ischemic size was curved on two-dimensional images by the trackball method and then compared with the pathologically ischemic size. And then longitudinal strain rates were compared in the cut-off value, adjacent non-ischemic and ischemic segments at which the cut-off point was defined by changing the curve M-mode of strain rate after ischemia.

RESULTSLinear correlation existed between pathology and strain rate ischemic size (r = 0.884, P < 0.001). The SR parameters were lower in ischemia and cut-off point than in non-ischemic segments. The peak SRs of systole (S(SR)), early diastole (E(SR)), late diastole (A(SR)), strain during ejection time (epsilon(et)), and the maximum length change during the entire heart cycle (epsilon(max)) in ischemic segments lowered (P < 0.05). Time to onset of regional relaxation (T(R)) was prolonged (P = 0.012).

CONCLUSIONSR imaging can accurately assess the size of ischemic myocardium.

Animals ; Dogs ; Echocardiography, Doppler ; methods ; Female ; Male ; Myocardial Ischemia ; diagnostic imaging ; pathology ; Ventricular Function, Left ; physiology

OBJECTIVETo assess the value of velocity vector imaging (VVI) and quantitative tissue velocity imaging (QTVI) in assessing left ventricular diastolic function of the dogs with acute myocardial ischemia.

METHODSSix healthy mongrel dogs were subjected to ligation of the left circumflex artery or left anterior descending artery to induce coronary artery stenosis of varying degrees. The mean peak diastolic velocity (Em) of the ventricular walls around the mitral annulus was recorded with VVI or QTVI in the coronary blood flow. The left ventricular end diastolic pressure (LVEDP) was measured with pigtail catheter in the left ventricle.

RESULTSAs the coronary blood flow decreased, LVEDP was gradually increased, and Em measured by VVI or QTVI were also gradually decreased. A good linear correlation was shown between Em measured by VVI or QTVI and LVEDP (r=-0.834, P<0.001, and r=-0.68, P<0.001, respectively). A significant difference was observed in the correlation coefficient between VVI and QTVI (Z=2.625, P=0.0087).

CONCLUSIONVVI and QTVI both provide good noninvasive means for measuring left ventricular diastolic function. VVI, a new echocardiographic modality without angular dependence, is better than QTVI in evaluating left ventricular diastolic function.

Animals ; Disease Models, Animal ; Dogs ; Echocardiography ; methods ; Male ; Myocardial Ischemia ; diagnostic imaging ; physiopathology ; Ventricular Function, Left

Blood Flow Velocity ; Coronary Circulation ; Coronary Vessels/diagnostic imaging* ; Humans ; Microcirculation ; Myocardial Ischemia ; Radioisotopes

This paper is aimed to investigate the influence of gated myocardial perfusion imaging (G-MPI) with 8- and 16-frame acquisition models on the assessment of left ventricular function. Patients prepared for stress and rest G-MPI were prospectively recruited from January 2010 to January 2011 in the Department of Nuclear Medicine of West China Hospital, Sichuan University. Two separate G-MPI studies, one with 8 and the other with 16 frames, were simultaneously acquired during a single gantry orbit using Concurrent Imaging technique. We calculated the left ventricular ejection fraction (EF) and volumes using the Auto Quant software. Forty-eight patients (29 men, 19 women; average age 51 +/- 16 years old) were finally analyzed. The differences in left ventricular EF between 8- and 16-frame were small: 3.27% (95% CI: 6.41%-0.12%) for post-stress and 3.13% (95% CI: 5.93%-0.32%) for rest. Both using 8 and 16 frames, there were significantly larger volumes and lower EF in patients with stress-induced ischemia than without. As for detecting left ventricular EF, 8-frame and 16-frame acquisition models should not be mutually alternated.
Adult ; Aged ; Female ; Gated Blood-Pool Imaging ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; diagnostic imaging ; physiopathology ; Myocardial Ischemia ; diagnostic imaging ; physiopathology ; Myocardial Perfusion Imaging ; methods ; Radiopharmaceuticals ; Stroke Volume ; physiology ; Technetium Tc 99m Sestamibi ; Ventricular Function, Left ; physiology

Objective: To evaluate the prognostic value of left ventricular ejection fraction (LVEF) reserve assessed by gated SPECT myocardial perfusion imaging (SPECT G-MPI) for major adverse cardiovascular event (MACE) in patients with coronary artery disease. Methods: This is a retrospective cohort study. From January 2017 to December 2019, patients with coronary artery disease and confirmed myocardial ischemia by stress and rest SPECT G-MPI, and underwent coronary angiography within 3 months were enrolled. The sum stress score (SSS) and sum resting score (SRS) were analyzed by the standard 17-segment model, and the sum difference score (SDS, SDS=SSS-SRS) was calculated. The LVEF at stress and rest were analyzed by 4DM software. The LVEF reserve (ΔLVEF) was calculated (ΔLVEF=stress LVEF-rest LVEF). The primary endpoint was MACE, which was obtained by reviewing the medical record system or by telephone follow-up once every twelve months. Patients were divided into MACE-free and MACE groups. Spearman correlation analysis was used to analyze the correlation between ΔLVEF and all MPI parameters. Cox regression analysis was used to analyze the independent factors of MACE, and the optimal SDS cutoff value for predicting MACE was determined by receiver operating characteristic curve (ROC). Kaplan-Meier survival curves were plotted to compare the difference in the incidence of MACE between different SDS groups and different ΔLVEF groups. Results: A total of 164 patients with coronary artery disease [120 male; age (58.6±10.7) years] were included. The average follow-up time was (26.5±10.4) months, and a total of 30 MACE were recorded during follow-up. Multivariate Cox regression analysis showed that SDS (HR=1.069, 95%CI: 1.005-1.137, P=0.035) and ΔLVEF (HR=0.935, 95%CI: 0.878-0.995, P=0.034) were independent predictors of MACE. According to ROC curve analysis, the optimal cut-off to predict MACE was a SDS of 5.5 with an area under the curve of 0.63 (P=0.022). Survival analysis showed that the incidence of MACE was significantly higher in the SDS≥5.5 group than in the SDS<5.5 group (27.6% vs. 13.2%, P=0.019), but the incidence of MACE was significantly lower in the ΔLVEF≥0 group than in theΔLVEF<0 group (11.0% vs. 25.6%, P=0.022). Conclusions: LVEF reserve (ΔLVEF) assessed by SPECT G-MPI serves as an independent protective factor for MACE, while SDS is an independent risk predictor in patients with coronary artery disease. SPECT G-MPI is valuable for risk stratification by assessing myocardial ischemia and LVEF.
Humans ; Male ; Middle Aged ; Aged ; Coronary Artery Disease/diagnostic imaging* ; Stroke Volume ; Myocardial Perfusion Imaging ; Retrospective Studies ; Ventricular Function, Left ; Myocardial Ischemia

OBJECTIVETo investigate the clinical implications of relationship between myeloperoxidase and acute coronary syndromes (ACS).

METHODS176 consecutive patients who underwent coronary angiography for coronary atherosclerosis were divided into four groups according to the quartile of MPO Level. The characters and the relationship between MPO and the elements were studied in every group.

RESULTS(1) ACS rate (36.2%) in the fourth quartile group of MPO level was 6 times higher than that (5.2%) in the first quartile group of MPO level, P < 0.01. (2) Gensini score (65.6 +/- 30.3) in the fourth quartile group of MPO level was significantly higher than that (17.3 +/- 10.2) in the first quartile group (P < 0.01). WBC [(7.7 +/- 1.6) x 10(9)/L] in the fourth quartile group was also significantly higher than that [(6.6 +/- 1.8) x 10(9)/L] in the first quartile group, P < 0.05. (3) When TnI < or = 0.05 ng/ml, MPO level had a positive correlation with Gensini score (r = 0.321, P = 0.002) and WBC (r = 0.230, P = 0.025). (4) Kaplan-meier event rate curve showed that there was a significant difference of the terminus incident (death, no causing death AMI, vessel reestablish and incidence rate of CABG add up) between the groups > or = 62.9 AUU/L and < 62.9 AUU/L of MPO serum level at 6-month follow-up visit (chi(2) = 13.5, P = 0.01).

CONCLUSIONActivity level of MPO in human serum seems a good biomarker for diagnosing and predicting ACS, which may be especially helpful in predicting the risk of myocardial infarction in patients with acute chest pain during 6-month follow up.

Acute Coronary Syndrome ; diagnostic imaging ; enzymology ; physiopathology ; Adult ; Angina, Unstable ; diagnostic imaging ; enzymology ; Coronary Angiography ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; enzymology ; Myocardial Ischemia ; diagnostic imaging ; enzymology ; Peroxidase ; blood ; Troponin I ; metabolism

BACKGROUNDPostsystolic shortening (PSS) has been proposed as a marker of myocardial dysfunction. Strain rate imaging (SRI) is a novel ultrasonic technique, allowing reliable and noninvasive measurement of myocardial deformation. The purpose of this study was to investigate the characteristics of myocardial longitudinal PSS by SRI in ischemic and infarct myocardium in patients with coronary artery disease, and to explore its clinical applicability.

METHODSEleven patients with angina pectoris, 21 patients with myocardial infarction and 20 healthy subjects were included in the study. Apical four-, three- and two-chamber views were displayed; and septal, lateral, anteroseptal, posterior, anterior and inferior walls of the left ventricle were scanned, respectively. PSS strain (epsilon(pss)), the ratio of epsilon(pss) and systolic strain (epsilon(pss)/epsilon(sys)), the ratio of epsilon(pss) and maximum strain (epsilon(pss)/epsilon(max)) and the duration of PSS (T(pss)) in ischemic, infarct and normal myocardium were analyzed.

RESULTSPSS was found more frequent in the ischemic and infarct segments compared with the normal segments (39% vs 22% and 56% vs 22%, respectively; both P < 0.01). It was even more frequent in the infarct segments than in the ischemic segments (56% vs 39%, P < 0.01). The absolute magnitude of epsilon(pss), epsilon(pss)/epsilon(sys), epsilon(pss)/epsilon(max) were significantly larger and T(pss) significantly longer in the ischemic and infarct segments compared with that in the normal myocardium (P < 0.01). epsilon(pss)/epsilon(sys), epsilon(pss)/epsilon(max) were even larger and T(pss) even longer in the infarct than in the ischemic segments (P < 0.01).

CONCLUSIONSPSS is a common and important feature of the ischemic and infarct myocardium. epsilon(pss), epsilon(pss)/epsilon(sys), epsilon(pss)/epsilon(max) and T(pss) as measured by SRI may be promising markers for the quantitative assessment of regional myocardial dysfunction in patients with coronary artery disease. epsilon(pss)/epsilon(sys), epsilon(pss)/epsilon(max) and T(pss) may be helpful in differentiating infarct from ischemic myocardium.

Aged ; Coronary Artery Disease ; diagnostic imaging ; physiopathology ; Echocardiography ; methods ; Heart ; physiopathology ; Humans ; Middle Aged ; Myocardial Ischemia ; diagnostic imaging ; physiopathology ; Myocardium ; pathology ; Systole