Early Perfusion Defects Research Articles

Early cardiac perfusion defects after left-sided radiation therapy for breast cancer: is there a volume response?

Cardiac single-photon emission computed tomography (SPECT) is often used to identify defects in myocardial perfusion due to atherosclerotic coronary artery disease. It was also used in studies to evaluate radiation therapy (RT)-associated cardiac abnormalities. In the current review, we aim to evaluate the rates of post-RT cardiac SPECT early perfusion abnormalities and relate this to the irradiated left ventricular volume. The studies cited in this systematic review were identified using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Six studies between 1996 and 2016 fulfilled the inclusion criteria. The reported perfusion defects in these studies were seen in the apical and anterolateral aspects of the left ventricle. Three studies show correlation between the percent of the left ventricle within the RT-field and percent of patients with early perfusion defects on cardiac SPECT. In two studies that used cardiac sparing techniques (such as deep inspiration), that resulted in a low mean heart dose, no perfusion defects were noted. Data suggest that incidental irradiation of the heart in cases of left breast/chest wall RT can result in early post-RT perfusion defects on cardiac SPECT. There appears to be strong dose/volume dependence to the risk, and hence techniques to reduce cardiac exposure are recommended.

Cardiovascular magnetic resonance in systemic sclerosis: "Pearls and pitfalls".

Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular dysfunction and excessive fibrosis, involving internal organs including the heart. The estimated prevalence of cardiac involvement in SSc is high and remains subclinical until the late stages. It is either primary, related to myocardial inflammation and fibrosis, or secondary, due to pulmonary arterial hypertension (SSc-PAH) or systemic hypertension, in those patients with renal involvement. Cardiovascular magnetic resonance (CMR) is a useful tool for the early assessment of cardiac involvement in SSc. It is the gold standard technique to assess ventricular volumes,ejection fraction, and in particular is very useful to reliably and non-invasively detect myocardial inflammation, early perfusion defects, and myocardial fibrosis. However, the CMR evaluation in SSc may be problematic, because of cardiac and respiratory artefacts, commonly found in these patients. Therefore, a high level of expertise is necessary for both acquisition and interpretation of CMR images in SSc.

Assessment of myocardial viability using multidetector computed tomography in patients with reperfused acute myocardial infarction

To assess the prognostic value of 64-section multidetector computed tomography (MDCT) to predict follow-up myocardial dysfunction and functional recovery after reperfusion therapy in patients with acute myocardial infarction (MI) as defined by echocardiography. After reperfusion therapy for acute MI, 71 patients underwent two-phase contrast-enhanced MDCT and follow-up echocardiography. MDCT findings were compared with echocardiographic findings using kappa statistics. The areas under the receiver operating characteristic curves (AUCs) and the odds ratios (ORs) of early perfusion defects (EPD), delayed enhancement (DE), and residual perfusion defects (RPD) for predicting follow-up myocardial dysfunction and functional recovery were calculated on a segmental basis. The presence of transmural EPD (EPD(TM)) or RPD showed good agreement (k = 0.611 and 0.658, respectively) with follow-up myocardial dysfunction, while subendocardial EPD (EPD(sub)) or subendocardial DE (DE(sub)) showed fair agreement with follow-up myocardial dysfunction (k = 0.235 and 0.234, respectively). The AUC of RPD (0.796) was superior (p < 0.001 and 0.031, respectively) to those of EPD(TM) (0.761) and DE(TM) (0.771). The presence of EPD(TM), DE(TM), and RPD were significant, independent positive predictors of follow-up myocardial dysfunction (OR = 6.4, 1.9, and 9.8, respectively). EPD(TM) was a significant, independent negative predictor of myocardial functional recovery (OR = 0.13). Abnormal myocardial attenuation on two-phase MDCT after reperfusion therapy may provide promising information regarding myocardial viability in patients with acute MI.

Is Functional Improvement after Myocardial Infarction Predicted with Myocardial Enhancement Patterns at Multidetector CT?

To prospectively evaluate the sensitivity of myocardial early perfusion defects (EDs) and late enhancement (LE) at multidetector computed tomography (CT) following acute myocardial infarction (AMI) to predict segment myocardial dysfunction and myocardial functional recovery (MFR), by using echocardiography as the reference standard. Institutional review board approval and informed consent were obtained. Twenty-six patients (25 men, one woman; mean age, 53 years+/-9 [standard deviation]), underwent baseline multidetector CT, coronary angiography, and echocardiography within a week of AMI and a follow-up echocardiography at 3 months. ED, LE, and late hypoattenuation were compared with regional left ventricular function and MFR. A logistic regression model and generalized estimating equation analysis were applied to estimate the predictive effect of ED and LE. Differences between groups were evaluated by using nonpaired Student t tests. All EDs and LE corresponded with AMI location determined by using angiography and echocardiography. For occluded arteries (n=5), no relationship was found between the presence of ED or LE and MFR. For patent arteries (n=21), presence of LE had a respective sensitivity and specificity of 73% and 85% for predicting follow-up segment dysfunction, compared with 57% and 90% for ED. In abnormal baseline segments, nonrecovery was clearly related to the presence and size of segment defect area for both ED (odds ratio: 1.95 [95% confidence interval: 0.9, 4.1] per square centimeter) and LE (odds ratio: 1.85 [95% confidence interval: 1.2, 2.9] per square centimeter). Segments that recovered had significantly lower prevalence of ED and LE, and if present, were significantly smaller than in segments remaining abnormal (P<.05). The presence and size of ED and LE at multidetector CT is closely related to follow-up segment myocardial dysfunction and MFR.

Early and Delayed Myocardial Enhancement in Myocardial Infarction Using Two-Phase Contrast-Enhanced Multidetector-Row CT

ObjectiveThe purpose of this study was to describe the myocardial enhancement patterns in patients with myocardial infarction using two-phase contrast-enhanced multidetector-row computed tomography (MDCT).Materials and MethodsTwenty-three patients with clinically proven myocardial infarction (17 acute myocardial infarction [AMI] and 6 chronic myocardial infarction [CMI]) were examined with two-phase contrast-enhanced ECG-gated MDCT. The presence, location, and patterns of myocardial enhancement on two-phase MDCT images were compared with infarcted myocardial territories determined by using electrocardiogram, echocardiography, thallium-201 single photon emission computed tomography, catheter and MDCT coronary angiography.ResultsAfter clinical assessment, the presence of myocardial infarctions were found in 27 territories (19 AMI and 8 CMI) of 23 patients. Early perfusion defects were observed in 30 territories of all 23 patients. Three territories not corresponding to a myocardial infarction were detected in three patients with AMI and were associated with artifacts. Fourteen of perfusion defects were in the left anterior descending artery territory, four in the left circumflex artery territory, and nine in the right coronary artery territory. Delayed enhancement was observed in 25 territories (17 AMI and 8 CMI) of 21 patients. Delayed enhancement patterns were variable. Transmural early perfusion defects (n =12) were closely associated with transmural late enhancement (n = 5) and subendocardial residual defect with subepicardial late enhancement (n = 5).ConclusionMyocardial infarction showed early perfusion defects and variable delayed enhancement patterns on two-phase contrast-enhanced MDCT. Delayed enhancement technique of MDCT could provide additional information of the location and extent of infarcted myocardium, and could be useful to plan appropriate therapeutic strategies in patients with AMI.

Myocardial enhancement pattern in patients with acute myocardial infarction on two-phase contrast-enhanced ECG-gated multidetector-row computed tomography

To evaluate the myocardial enhancement pattern of the left ventricle on two-phase contrast-enhanced electrocardiogram (ECG)-gated multidetector computed tomography (MDCT) images in patients with acute myocardial infarction (AMI). Two-phase contrast-enhanced ECG-gated MDCT examinations were performed in 16 patients with AMI. The presence, location and pattern of myocardial enhancement were evaluated. MDCT findings were compared with the catheter angiographic results. Subendocardial (n = 9) or transmural (n = 6) area of early perfusion defects of the myocardium was detected in 15 of 16 patients (94%) on early-phase CT images. Variable delayed myocardial enhancement patterns on late-phase CT images were observed in 12 patients (75%): (1) subendocardial residual perfusion defect and subepicardial late enhancement (n = 6); (2) transmural late enhancement (n = 1); (3) isolated subendocardial late enhancement (n=1); and (4) isolated subendocardial residual perfusion defect (n = 2). On catheter angiography, 14 of 15 corresponding coronary arteries showed significant stenosis. Variable abnormal myocardial enhancement pattern was seen on two-phase, contrast-enhanced ECG-gated MDCT in patients with AMI. Assessment of myocardial attenuation on CT angiography gives additional information of the location and extent of infarction.

Computed tomography assessment of myocardial perfusion, viability, and function.

In addition to coronary artery assessment, contrast-enhanced multidetector spiral computed tomography (CE-MDCT) can provide valuable information about myocardial perfusion. Using CE-MDCT, myocardial perfusion defects are often observed in the early phase of the contrast bolus (early defect (ED)), with residual defects (RDs) and late enhancement (LE) observed in the late phase in myocardial infarction (MI). However, the clinical significance of EDs, RDs, and LE has not yet been fully described. This work reviews myocardial viability and function by CE-MDCT based on our prior data by including contrast-enhanced single-slice (detector) CT (CE-SSCT) and CE-MDCT. Recently, equivalent results were obtained, as seen in CE-SSCT with images by CE-MDCT. In this review, images that were acquired by MDCT will be presented. In this work, the following items will be the focus: myocardial enhancement patterns (EDs, LE, and RDs), early perfusion defects and their relationship to wall thickness (WT) and wall motion, early CT perfusion defects vs. Tl-201 single photon emission CT (SPECT), the protocol for performing dual-phase contrast CT, classification of enhancement patterns, enhancement patterns on dual-phase CE-MDCT vs. left ventricular functional recovery and WT, changes in enhancement patterns in conjunction with healing stage, enhancement patterns on dual-phase CE-MDCT vs. 201Tl/99mTc-pyrophosphate (dual-isotope SPECT), the clinical meaning of each enhancement pattern, pitfalls of enhancement patterns and other diseases, and study limitations and the future of MDCT.

Myocardial Perfusion Abnormalities Early (12–24 h) after Coronary Stenting or Balloon Angioplasty: Implications Regarding Pathophysiology and Late Clinical Outcome

Objective: We prospectively examined the prevalence of reversible perfusion defects on very early (12–24 h) thallium-201 single photon emission computed tomography (SPECT) scintigraphy after angiographically successful percutaneous coronary intervention (PCI) by stenting and/or stand-alone balloon angioplasty and the predictive value of these defects for late target lesion revascularization (TLR). Patients and Methods: 83 consecutive patients undergoing PCI for 88 lesions (38 balloon angioplasties, 50 stents) underwent very early (12–24 h) SPECT thallium-201 scintigraphy at rest and following administration of 0.7 mg/kg intravenous dipyridamole after PCI. Univariate and multivariate clinical, procedural and scintigraphic correlates of target lesion revascularization during long-term follow-up were examined. Results: Coronary stenting achieved a larger immediate post-PCI minimal luminal dimension (2.7 ± 0.4 vs. 2.1 ± 0.4 mm, p < 0.001) and less residual stenosis (4 ± 12 vs. 19 ± 11%, p < 0.001) than stand-alone balloon angioplasty. Nonetheless, early reversible perfusion defects were similarly present in the territory supplied by 36% of stented lesions and 32% of lesions treated by balloon angioplasty (NS). Of 81 lesions (76 patients) available for long-term clinical follow-up, TLR was performed in 11% of the stent group and 14% of the balloon angioplasty group (NS). By multivariate logistic regression analysis, diabetes mellitus was the only predictor of late TLR (p < 0.05). The type of intervention (balloon or stent) predicted neither early perfusion defects nor late TLR. Conclusions: Early 201-thallium SPECT scintigraphy was abnormal in a third of patients treated by stand-alone balloon angioplasty or by stent placement. The very early SPECT scintigraphic findings did not differentiate between balloon and stent and did not predict late TLR.