Severity Of Perfusion Defects Research Articles

External validation and update of the J-ACCESS model in an Italian cohort of patients undergoing stress myocardial perfusion imaging

BackgroundCardiovascular risk models are based on traditional risk factors and investigations such as imaging tests. External validation is important to determine reproducibility and generalizability of a prediction model. We performed an external validation of t the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT (J-ACCESS) model, developed from a cohort of patients undergoing stress myocardial perfusion imaging. MethodsWe included 3623 patients with suspected or known coronary artery disease undergoing stress single-photon emission computer tomography (SPECT) myocardial perfusion imaging at our academic center between January 2001 and December 2019. ResultsIn our study population, the J-ACCESS model underestimated the risk of major adverse cardiac events (cardiac death, nonfatal myocardial infarction, and severe heart failure requiring hospitalization) within three-year follow-up. The recalibrations and updated of the model slightly improved the initial performance: C-statistics increased from 0.664 to 0.666 and Brier score decreased from 0.075 to 0.073. Hosmer–Lemeshow test indicated a logistic regression fit only for the calibration slope (P = .45) and updated model (P = .22). In the update model, the intercept, diabetes, and severity of myocardial perfusion defects categorized coefficients were comparable with J-ACCESS. ConclusionThe external validation of the J-ACCESS model as well as recalibration models have a limited value for predicting of three-year major adverse cardiac events in our patients. The performance in predicting risk of the updated model resulted superimposable to the calibration slope model.

Systemic-pulmonary collateral supply associated with clinical severity of chronic thromboembolic pulmonary hypertension: a study using intra-aortic computed tomography angiography

ObjectivesTo assess whether systemic-pulmonary collaterals are associated with clinical severity and extent of pulmonary perfusion defects in chronic thromboembolic pulmonary hypertension (CTEPH).MethodsThis prospective study was approved by a local ethics committee. Twenty-four patients diagnosed with inoperable CTEPH were enrolled between July 2014 and February 2017. Systemic-pulmonary collaterals were detected using pulmonary vascular enhancement on intra-aortic computed tomography (CT) angiography. The pulmonary enhancement parameters were calculated, including (1) Hounsfield unit differences (HUdiff) between pulmonary trunks and pulmonary arteries (PAs) or veins (PVs), namely HUdiff-PA and HUdiff-PV, on the segmental base; (2) the mean HUdiff-PA, mean HUdiff-PV, numbers of significantly enhanced PAs and PVs, on the patient base. Pulmonary perfusion defects were recorded and scored using the lung perfused blood volume (PBV) based on intravenous dual-energy CT (DECT) angiography. Pearson’s or Spearman’s correlation coefficients were used to evaluate correlations between the following: (1) segment-based intra-aortic CT and intravenous DECT parameters (2) patient-based intra-aortic CT parameters and clinical severity parameters or lung PBV scores. Statistical significance was set at p < 0.05.ResultsSegmental HUdiff-PV was correlated with the segmental perfusion defect score (r = 0.45, p < 0.01). The mean HUdiff-PV was correlated with the mean pulmonary arterial pressure (PAP) (r = 0.52, p < 0.01), cardiac output (rho = − 0.41, p = 0.05), and lung PBV score (rho = 0.43, p = 0.04). And the number of significantly enhanced PVs was correlated with the mean PAP (r = 0.54, p < 0.01), pulmonary vascular resistance (r = 0.54, p < 0.01), and lung PBV score (rho = 0.50, p = 0.01).ConclusionsPV enhancement measured by intra-aortic CT angiography reflects clinical severity and pulmonary perfusion defects in CTEPH.Key Points• Intra-aortic CT angiography demonstrated heterogeneous enhancement within the pulmonary vasculature, showing collaterals from the systemic arteries to the pulmonary circulation in CTEPH.• The degree of systemic-pulmonary collateral development was significantly correlated with the clinical severity of CTEPH and may be used to evaluate disease progression.• The distribution of systemic-pulmonary collaterals is positively correlated with perfusion defects in the lung segments in CTEPH.

In-depth cardiovascular and pulmonary assessments in children with multisystem inflammatory syndrome after SARS-CoV-2 infection: A case series study.

We assessed PET‐CT myocardial blood flow (MBF) using N‐13 ammonia, brachial flow‐mediated dilation, and cardiopulmonary exercise test in five post‐discarged MIS‐C survivors. None of the patients (median age: 9, range: 7‐18 years; 3 females; 2 males) had preexisting pediatric chronic conditions. At the follow‐up visit, two patients exhibited severe perfusion defect developed in the left ventricular cavity, suggesting extensive myocardial ischemia (MBF <2.0) and one patient showed persistent mild pericardial effusion. Others two patients demonstrated endothelial dysfunction. Nevertheless, all patients had lower predicted values in the VO2peak, VO2VAT, OUES, and O2 Pulse (range: 35.2%–64.5%; 15.6%–38.2%; 1.0–1.3 L/min; 4–7 ml/beat), respectively. Our d suggested that previously health MIS‐C patients had impaired MBF, endothelial dysfunction and lower cardiopulmonary capacity at follow‐up analysis. Multidisciplinary further investigations should be conducted to reinforce these findings.

Cardiac schockwave therapy in the treatment of ischemic heart disease patiens with refractive angina pectoris

Objective: To evaluate of the effectiveness of cardiac shockwave therapy in the treatment of ischemic heart disease with refractive angina pectoris. Subject and method: A prospective, cross-sectional study with comparison and follow-up for 6 months on 50 patients with refractive angina pectoris from January 2017 to January 2020. The protocol application of 100 shocks/spot at 0.09mJ/mm2 energy flux density for 3 - 6 spots each time, with three times per week at each series for three series at 1, 5, 9 weeks. Result: The average age was 71.32 ± 10.5 years, men accounted for 78%. The symptoms of angina improved significantly (amount of chest pain 5.87 ± 2.7 to 0.28 ± 0.45 times; Nitrat consumed per week from 6.3 ± 3.5 to 0.3 ± 0.5 tablets/week). The 6-minute walking test all improved (278.1 ± 71m compared with 390.5 ± 42.3m). CCS angina class improved significant. NYHA grade improved significantly (NYHA III from 40.7% to 11.1%, NYHA II from 51.9% to 33.3%). Pro-BNP decreased (994.99 ± 1708.9 to 429.0 ± 453.9 pg/ml). WSMI decreased from 1.49 ± 0.22 to 1.24 ± 0.12, GLS improved from -9.79 ± 2.68 to -12.7 ± 2.42. Average score of SSS, SRS, SDS markedly improved with p&lt;0.05 by SPECT. The degree of severe perfusion defect and the wide perfusion defect area decreased significantly after treatment by 52% to 12% and 58% to 28%, respectively. Conclusion: Cardiac shockwave therapy improved clinical symptoms and increased myocardial perfusion in ischemic heart disease with refractive angina pectoris.

Static CT myocardial perfusion imaging: image quality, artifacts including distribution and diagnostic performance compared to 82Rb PET

BackgroundRubidium-82 positron emission tomography (82Rb PET) MPI is considered a noninvasive reference standard for the assessment of myocardial perfusion in coronary artery disease (CAD) patients. Our main goal was to compare the diagnostic performance of static rest/ vasodilator stress CT myocardial perfusion imaging (CT-MPI) to stress/ rest 82Rb PET-MPI for the identification of myocardial ischemia.MethodsForty-four patients with suspected or diagnosed CAD underwent both static CT-MPI and 82Rb PET-MPI at rest and during pharmacological stress. The extent and severity of perfusion defects on PET-MPI were assessed to obtain summed stress score, summed rest score, and summed difference score. The extent and severity of perfusion defects on CT-MPI was visually assessed using the same grading scale. CT-MPI was compared with PET-MPI as the gold standard on a per-territory and a per-patient basis.ResultsOn a per-patient basis, there was moderate agreement between CT-MPI and PET-MPI with a weighted 0.49 for detection of stress induced perfusion abnormalities. Using PET-MPI as a reference, static CT-MPI had 89% sensitivity (SS), 58% specificity (SP), 71% accuracy (AC), 88% negative predictive value (NPV), and 59% positive predictive value (PPV) to diagnose stress-rest perfusion deficits on a per-patient basis. On a per-territory analysis, CT-MPI had 73% SS, 65% SP, 67% AC, 90.8% NPV, and 34% PPV to diagnose perfusion deficits.ConclusionsCT-MPI has high sensitivity and good overall accuracy for the diagnosis of functionally significant CAD using 82Rb PET-MPI as the reference standard. CT-MPI may play an important role in assessing the functional significance of CAD especially in combination with CCTA.

The Role of Myocardial Perfusion Imaging in Patients with Diabetes Mellitus

Abstract Diabetes mellitus is a complex pathology with increasing incidence, associated with an increased risk of coronary heart disease. Myocardial perfusion imaging (MPI) is an important diagnostic tool for the evaluation of coronary artery disease (CAD), with a high prognostic value. Objective. The aim of this study was to evaluate the role of stress-rest MPI in the assessment of patients with DM and suspected or confirmed CAD. Method. We performed a retrospective analysis of 128 patients who underwent stress-rest MPI in our department, all of them with coronary angiography (CA) available. All patients underwent stress rest myocardial perfusion SPECT using a 1-day or 2-day protocol. The radiopharmaceuticals used were 99m-Tc-MIBI or tetrofosmin. The study was performed with a gated protocol SPECT, synchronous with the ECG, using a dual-head gamma camera. Patients were divided in 4 subgroups based on the presence of DM and of significant CA changes. Results. In the group of patients with significant coronary disease on CA and previously diagnosed DM, number of perfusion defects on the stress-rest MPI were higher and also the presence of systolic disfunction and the severity of defects. Our results support the idea that the severity and extent of myocardial perfusion defects are greater in diabetic patients than in non-diabetic patients. Conclusions. We can consider myocardial perfusion SPECT with 99mTc-labeled agents as a feasible method for the diagnosis and evaluation of CAD and for the management of diabetic patients.

Q waves in ischemic cardiomyopathy.

Q waves may be observed in the absence of non-viable tissue. However, their scintigraphic translation in patients with ischemic cardiomyopathy (ICM) has not been properly assessed. This study sought to establish the determinants of Q waves in the absence of non-viable tissue and the diagnostic accuracy in this population. A retrospective study enrolling 487 consecutive patients (67.0 [57.4 - 75.4] years), with ICM, LVEF < 40% and narrow QRS who underwent stress-rest 99m-Tc SPECT was conducted. A 17-segment model for myocardium was used: Myocardium was divided in basal (1 to 6), mid (7 to 12), apical (13 to 16) and apex (17) segments. Non-viable tissue was defined as a severe perfusion defect without systolic thickening. Patients with Q waves (65.7%) had more non-viable tissue, more extensive scar and less ischemia. Q waves had a moderate correlation with non-viable tissue (AUC = 0.63) and were associated with the extension of the scar. After excluding patients with non-viable tissue in any myocardial segment, Q waves were observed in 51.9% of the patients, of which 78.1% had a scar fulfilling viability criteria. The presence of Q waves was associated with the location of these scars in a base-to-apex axis (OR = 1.88 [1.35-2.62] for segment towards the apex) and their extent (OR = 1.19 [1.05 - 1.35] for each segment). In patients with ICM, Q waves discriminate poorly viable from non-viable tissue. Q waves in this population may be due to extensive scars fulfilling viability criteria located in apical segments.

Reduced Heart Rate Response during Drug-Induced Stress Is Related to the Severity of Perfusion Defect

Introduction: During the pharmacological stress test with dipyridamole, a normal hemodynamic response is slightly reduced blood pressure and raised heart rate (HR). However, sometimes the HR response is reduced. This study investigated the relationship between the HR response during the dipyridamole stress test and the severity of the perfusion defects using Thallium 201 myocardial perfusion imaging. Methods: We enrolled 50 patients undergoing dipyridamole stress at the nuclear cardiology Lab, Main University Hospital of Alexandria. Standard dipyridamole protocol (infusion over 4 min) and standard thallium 201 protocol (2 min after dipyridamole infusion) were followed. If the heart rate (HR) ratio (peak HR/rest HR) was 1.20 or less, it was considered a reduced response. Total perfusion defect (TPD), summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for myocardial perfusion were calculated. Patients with reduced HR response and normal HR responses were compared and independent predictors of reduced HR response were determined. Results: About 56% of patients had reduced HR response; which included a high number of patients with a history of dyslipidemia and diabetes mellitus. The reduced HR response group showed lower SSS, SRS. The analysis showed that the independent predictors of reduced HR response were rest HR, SSS, and diabetes mellitus. Conclusions: Reduction in the HR response during the dipyridamole-induced stress test is related to the severity of perfusion defect, diabetes mellitus, and Dyslipidemia.

Brachial Artery “Low-Flow Mediated Constriction” Is Associated with Myocardial Perfusion Defect Severity and Mediated by an Altered Flow Pattern during Occlusion

Introduction: The relationship between low flow-mediated constriction (LFMC), a new proposed measure of endothelial function, with cardiovascular disease severity and its hypothesized stimulus, that is, low flow, has not been comprehensively evaluated. The study evaluated association between change in brachial artery diameter during constriction with severity of myocardial perfusion defect (PD) and alterations in different components of flow profile. Methods: Brachial artery responses to occlusion were assessed in 91 patients and 30 healthy subjects. Change in anterograde and retrograde blood flow velocities (delta anterograde blood flow velocity and retrograde blood flow velocity), anterograde shear rate and retrograde shear rate (delta ASR and RSR, respectively), and oscillatory shear index (delta) during forearm occlusion at 50 mm Hg above systolic pressure, from baseline was calculated. Myocardial perfusion was evaluated in patients using exercise single positron emission computed tomography and % myocardial PD was calculated from summed stress score. Results: LFMC emerged as independent predictor of defect severity after correcting for age and gender (p = 0.014). Sixty-seven patients (73.6%) and 15 healthy subjects (50%) showed constriction during occlusion. In stepwise backward regression analysis, RSR contributed 35.5% and ASR contributed 20.1% of the total 63.9% variability in artery diameter during occlusion. Conclusion: The results suggest that LFMC is independently associated with myocardial perfusion severity and is “mediated” by an altered flow profile during occlusion.

Myocardial ischemia by radionuclide imaging and long-term outcomes after kidney transplantation.

We examined the incidence of myocardial ischemia (MI) in kidney transplant recipients (KTR) using myocardial perfusion imaging (MPI), and its association with long-term outcomes after transplantation. A retrospective observational study was conducted of asymptomatic KTRs who underwent post-transplant MPI screening for MI, as defined by moderate to severe myocardial perfusion defects, post-stress myocardial stunning or balanced ischemia. A composite outcome of all-cause mortality, graft loss, and major adverse cardiovascular events (MACE) was examined over minimum 5years. We studied 135 KTRs who underwent 226 MPIs, with follow-up duration of 10 (7-13) years. 110 (81%) patients had normal MPIs, 11 (8%) had mild perfusion defects, and 14 (10%) had MI. Correspondingly, composite outcome developed in 6%, 27%, and 43% (p = 0.04), and MACE occurred in 7%, 0%, and 21% (p = 0.11), of the respective subgroups. Twenty-six patients developed the composite outcome after 5 (3-7) years post-transplantation, including 11 patients with MACE. On multivariate analysis, MI, higher low-density lipoprotein levels, and proteinuria > 0.3g/day independently predicted the composite outcome; only MI predicted MACE (all p < 0.05). Ninety-one patients had two serial MPIs, which increased the positive predictive value for MACE from 17 to 25%. Absence of MI had negative predictive value of 83% for MACE and 93% for the composite outcome. MI that is detected early post-kidney transplantation predicts long-term mortality, graft loss, and MACE in KTRs, with excellent negative but poor positive predictive values.

Papillary Trunk Bifurcation Angles as Major Determinants of Ocular Perfusion: A Cross-Sectional Study

Background: Notable work has been done by Cecile and Murray in as early as 1926, on the structural and topological aspects of vasculature based on the concept that blood vessel size and arrangement is such that it provides blood flow with minimum energy loss. In the theoretical analysis of arterial networks, the existence of geometric optimisation for enabling functional adequacy has long been suggested, but observational studies have not yet fully corroborated these theories. Data on branching or bifurcation angles of retinal microvasculature is not only insufficient but also inconclusive. Aim: Attending to this gap in information, we compared the central retinal artery (CRA) branching angles of known diabetics with healthy subjects and explored their possible role in determining the circulatory adequacy of human retina. Methods: This study was done on North Indian subjects attending retina clinics of prominent tertiary centers of north India during 2019 through 2020. Fundus images were acquired through convenience sampling from 860 consecutive eyes of 430 subjects. Fluorescein fundus angiography was followed up for diabetics. CRA branching angles from digitalized fundus photographs of known diabetics and healthy subjects was analyzed through semi-automated digital image management tool and the readings were clinically correlated to note the occurrence and severity of retinopathic perfusion defects was Results: We found marked differences between CRA branching angles among diabetics and healthy subjects and a significant correlation between branching anless and the occurrence and severity of retinopathic perfusion defects. Discussion and Conclusion: The orientation of retinal blood vessels on the fundus plane is not merely ‘a matter of chance’ in the anatomic chronicle of the human body; rather, it has biological heralds and functional consequences. Direction, branching, angles; all determine the efficacy and abundance of blood flow in the human retina that hold indispensible relevance for optimal vision and might be subtle indicators of micro vascular damage in disease states. This study has elucidated retinal vascular geometrics of healthy and diseased Indians, a knowledge that can improve our understanding of ‘abnormal features’ and ‘natural variants’ in retinal vascular architecture. In this study, we quantified the ‘structural factors’ behind perfusion defects of the Diabetic retina.

Mismatch Between Cardiac Magnetic Resonance Imaging and Invasive Physiology

A 74-year-old man returned to the clinic for follow-up of residual nonculprit lesions after reperfused acute inferior ST-segment elevation myocardial infarction. Stress cardiac magnetic resonance perfusion imaging demonstrated a severe perfusion defect in the anterior wall. Surprisingly, subsequent invasive assessment did not reveal hemodynamically significant obstruction in the nonculprit vessels. (Level of Difficulty: Beginners.)

Head-to-head comparison of lung perfusion with dual-energy CT and SPECT-CT

PurposeTo compare the quantitative and qualitative lung perfusion data acquired with dual energy CT (DECT) to that acquired with a large field-of-view cadmium-zinc-telluride camera single-photon emission CT coupled to a CT system (SPECT-CT). Materials and methodsA total of 53 patients who underwent both dual-layer DECT angiography and perfusion SPECT-CT for pulmonary hypertension or pre-operative lobar resection surgery were retrospectively included. There were 30 men and 23 women with a mean age of 65.4±17.5 (SD)years (range: 18–88years). Relative lobar perfusion was calculated by dividing the amount (of radiotracer or iodinated contrast agent) per lobe by the total amount in both lungs. Linear regression, Bland-Altman analysis, and Pearson's correlation coefficient were also calculated. Kappa test was used to test agreements in morphology and severity of perfusion defects assessed on SPECT-CT and on DECT iodine maps with a one-month interval. Wilcoxon rank sum test was used to compare the sharpness of perfusion defects and radiation dose among modalities. ResultsStrong correlations for relative lobar perfusion using linear regression analysis and Pearson's correlation coefficient (r=0.93) were found. Bland-Altman analysis revealed a −0.10 bias, with limits of agreement between [−6.01; 5.81]. With respect to SPECT- CT as standard of reference, the sensitivity, specificity, PPV, NPV, accuracy for lobar perfusion defects were 89.4% (95% CI: 82.6−93.4%), 96.5% (95% CI: 92.1−98.5%), 95.6% (95% CI: 90.9−97.8%), 91.4% (95% CI: 85.6−94.9%) and 93.0% (95% CI: 87.6−96.1%) respectively. High level of agreement was found for morphology and severity of perfusion defects between modalities (Kappa=0.84 and 0.86 respectively) and on DECT images among readers (Kappa=0.94 and 0.89 respectively). A significantly sharper delineation of perfusion defects was found on DECT images (P<0.0001) using a significantly lower equivalent dose of 4.1±2.3 (SD) mSv (range: 1.9–11.85mSv) compared to an equivalent dose of 5.3±1.1 (SD) mSv (range: 2.8–7.3mSv) for SPECT-CT, corresponding to a 21.2% dose reduction (P=0.0004). ConclusionDECT imaging shows strong quantitative correlations and qualitative agreements with SPECT-CT for the evaluation of lung perfusion.

Valor pronóstico de la cardiorresonancia magnética de estrés en pacientes ancianos

Introduction and objectivesSeveral trials have tested the diagnostic and prognostic value of stress cardiac magnetic resonance (CMR) in ischemic heart disease. However, scientific evidence is lacking in the older population, and the available techniques have limitations in this population. The aim of this study was to evaluate the usefulness of stress CMR in the elderly. MethodsWe prospectively studied consecutive patients referred for stress CMR to rule out myocardial ischemia. The cutoff age for the elderly population was 70 years. Stress CMR study was performed according to standardized international protocols. Hypoperfusion severity was classified according to the number of affected segments: mild (1-2 segments), moderate (3-4 segments), or severe (> 4 segments). We analyzed the occurrence of major events during follow-up (death, acute coronary syndrome, or revascularization). Survival was studied with the Kaplan-Meier method and multivariate Cox regression models. ResultsOf an initial cohort of 333 patients, 110 were older than 70 years. In 40.9% patients, stress CMR was positive for ischemia. The median follow-up was 26 [18-37] months. In elderly patients there were 35 events (15 deaths, 10 acute coronary syndromes, and 10 revascularizations). Patients with moderate or severe ischemia were at a higher risk of events, adjusted for age, sex, and cardiovascular risk (HR, 3.53 [95%CI, 1.41-8.79]; P=.01). ConclusionsModerate to severe perfusion defects in stress CMR strongly predict cardiovascular events in people older than 70 years, without relevant adverse effects.

A combined static-dynamic single-dose imaging protocol to compare quantitative dynamic SPECT with static conventional SPECT

BackgroundSPECT myocardial perfusion imaging (MPI) is a clinical mainstay that is typically performed with static imaging protocols and visually or semi-quantitatively assessed for perfusion defects based upon the relative intensity of myocardial regions. Dynamic cardiac SPECT presents a new imaging technique based on time-varying information of radiotracer distribution, which permits the evaluation of regional myocardial blood flow (MBF) and coronary flow reserve (CFR). In this work, a preliminary feasibility study was conducted in a small patient sample designed to implement a unique combined static-dynamic single-dose one-day visit imaging protocol to compare quantitative dynamic SPECT with static conventional SPECT for improving the diagnosis of coronary artery disease (CAD). MethodsFifteen patients (11 males, four females, mean age 71 ± 9 years) were enrolled for a combined dynamic and static SPECT (Infinia Hawkeye 4, GE Healthcare) imaging protocol with a single dose of 99mTc-tetrofosmin administered at rest and a single dose administered at stress in a one-day visit. Out of 15 patients, eleven had selective coronary angiography (SCA), 8 within 6 months and the rest within 24 months of SPECT imaging, without intervening symptoms or interventions. The extent and severity of perfusion defects in each myocardial region was graded visually. Dynamically acquired data were also used to estimate the MBF and CFR. Both visually graded images and estimated CFR were tested against SCA as a reference to evaluate the validity of the methods. ResultsOverall, conventional static SPECT was normal in ten patients and abnormal in five patients, dynamic SPECT was normal in 12 patients and abnormal in three patients, and CFR from dynamic SPECT was normal in nine patients and abnormal in six patients. Among those 11 patients with SCA, conventional SPECT was normal in 5, 3 with documented CAD on SCA with an overall accuracy of 64%, sensitivity of 40% and specificity of 83%. Dynamic SPECT image analysis also produced a similar accuracy, sensitivity, and specificity. CFR was normal in 6, each with CAD on SCA with an overall accuracy of 91%, sensitivity of 80%, and specificity of 100%. The mean CFR was significantly lower for SCA detected abnormal than for normal patients (3.86±1.06 vs 1.94±0. 0.67, P < 0.001). ConclusionsThe visually assessed image findings in static and dynamic SPECT are subjective, and may not reflect direct physiologic measures of coronary lesion based on SCA. The CFR measured with dynamic SPECT is fully objective, with better sensitivity and specificity, available only with the data generated from the dynamic SPECT method.

Reference parameters for left ventricular wall thickness, thickening, and motion in stress myocardial perfusion CT: Global and regional assessment

PurposeTo use adenosine-induced stress CT myocardial perfusion imaging (CT-MPI) to determine normal reference values for left ventricle (LV) wall thickness (WT) and motion parameters. MethodsThis study included 106 Korean subjects (52 men and 54 women) who underwent CT-MPI due to chest pain, but were not found to have any detectable mild or severe coronary artery disease or myocardial perfusion defect. The following quantitative parameters were assessed on the CT-MPI according to a 17-segment model: LV myocardial thickness at end-systolic (WTES) and end-diastolic (WTED) phases, systolic wall thickening (SWT), and wall motion (WM). The associations of the measured parameters with the subjects' demographic characteristics and comorbidities were also analyzed. ResultsSeptal wall (7.2 mm) and basal-level (7.7 mm) LV myocardium demonstrated significantly higher WT (p < 0.001). SWT was highest in lateral (77.8%, p < 0.014) and apical (78.9%, p = 0.009) myocardium, while lateral (7.7 mm) and basal (6.7 mm) myocardium exhibited the greatest WM (p < 0.001). WT was significantly higher in men and younger (<60 years) subjects (all, p < 0.001). Hypertensive individuals presented with significantly higher SWT (79.9%, p = 0.024). LV WT exhibited statistically significant correlations (all positive, except for age) with age, height, weight, body surface area, body mass index, and systolic blood pressure (all, p < 0.010). ConclusionsThe present study provides CT-MPI reference values for LV myocardial WT, SWT, and WM measured on an adult Korean population. Knowledge of such normal reference measurements would be beneficial for the efficient interpretation of CT-MPI examinations in populations of Asian ethnicity.

Prognostic role of stress cardiac magnetic resonance in the elderly.

Several trials have tested the diagnostic and prognostic value of stress cardiac magnetic resonance (CMR) in ischemic heart disease. However, scientific evidence is lacking in the older population, and the available techniques have limitations in this population. The aim of this study was to evaluate the usefulness of stress CMR in the elderly. We prospectively studied consecutive patients referred for stress CMR to rule out myocardial ischemia. The cutoff age for the elderly population was 70 years. Stress CMR study was performed according to standardized international protocols. Hypoperfusion severity was classified according to the number of affected segments: mild (1-2 segments), moderate (3-4 segments), or severe (> 4 segments). We analyzed the occurrence of major events during follow-up (death, acute coronary syndrome, or revascularization). Survival was studied with the Kaplan-Meier method and multivariate Cox regression models. Of an initial cohort of 333 patients, 110 were older than 70 years. In 40.9% patients, stress CMR was positive for ischemia. The median follow-up was 26 [18-37] months. In elderly patients there were 35 events (15 deaths, 10 acute coronary syndromes, and 10 revascularizations). Patients with moderate or severe ischemia were at a higher risk of events, adjusted for age, sex, and cardiovascular risk (HR, 3.53 [95%CI, 1.41-8.79]; P=.01). Moderate to severe perfusion defects in stress CMR strongly predict cardiovascular events in people older than 70 years, without relevant adverse effects.

Value of differential diagnosis of contrast-enhanced ultrasound in benign and malignant thyroid nodules with microcalcification.

Value of differential diagnosis of contrast-enhanced ultrasound in benign and malignant thyroid nodules with microcalcification was explored. A total of 184 patients with thyroid nodules with microcalcification, treated in People's Hospital of Shanxi Province from April 2015 to March 2017, were selected as research subjects. Contrast-enhanced ultrasound was used for imaging examination of the thyroid nodules. Three regions of interest were drawn at the positions with the strongest ultrasound imaging, for which the time-intensity curve (TIC), time to peak (Tp), peak intensity (Peak), area under curve (AUC) and mean transit time (MTT) were obtained separately. The features of contrast-enhanced ultrasound for malignant thyroid nodules were manifested as irregular focus edge, unclear boundary, low fiber reinforcement of the whole focus, uneven distribution of images and blood perfusion defect inside the focus, especially severe blood perfusion defect in the nodule center. The TIC showed a slow ascending and slow descending trend in general. The TIC features and the features of contrast-enhanced ultrasound for malignant thyroid nodules were prominently different from those for benign thyroid nodules. Compared with those in the surrounding normal tissues of thyroid gland, the Peak was remarkably shorter, and the AUC was notably smaller in the center and edge of malignant thyroid nodules (P<0.05); and the nodule center had obviously shorter Peak and smaller AUC than the nodule edge (P<0.05). Furthermore, in comparison with those of malignant thyroid nodules, the Peak was extended and AUC was enlarged markedly in the center and edge of benign thyroid nodules (P<0.05). In conclusion, the contrast-enhanced ultrasound can preferably compare the lesions of benign and malignant thyroid nodules with microcalcification, which possesses certain value in the differential diagnosis of benign and malignant thyroid nodules.

Risk stratification with vasodilator stress SPECT myocardial perfusion imaging in patients with elevated cardiac biomarkers

BackgroundAlthough the diagnostic accuracy and prognostic utility of vasodilator stress MPI have been well established in the non-acute setting, the efficacy of all of the vasodilator stressors in risk stratifying post-MI patients as well as the evaluation of cardiac troponin elevation of unclear etiology is not established. Accordingly, the aim of the present study was to investigate the prognostic efficacy of vasodilator stress MPI in the setting of elevated cardiac troponin to accurately risk stratify these higher-risk patients. MethodsAll patients from two tertiary centers, from 1/1/2010 through 12/31/2012, with elevated cardiac biomarkers within < 7 days and undergoing stress SPECT MPI testing were studied. Results of stress MPI were scored using a 17-segment model based on semiquantitative scoring as normal or abnormal (mild, moderate, or severe) using a total perfusion defect (TPD) of 0%, 1-10%, 10-20%, and > 20%. Mortality data through the year 2014 were obtained from the National Death Index, and survival analyses were performed. The primary endpoint was all-cause mortality with the secondary endpoint being cardiac mortality. ResultsA total of 503 patients were followed for an average of 33.6 ± 16.2 months, with a mean age of 69.3 years; 53.7% male; and a majority (88.7%) of them undergoing vasodilator stress. A significant increase in all-cause mortality was seen based on the severity of TPD results for all vasodilators (P < .0001) and regadenoson (P < .0001). Similar prognostic ability was seen for all-cause mortality. This association was maintained even after adjustment for cardiac risk factors, previous coronary disease, and troponin quartiles. MPI results (stress TPD and LVEF) added to traditional cardiac risk factors, and troponin values resulted in a significant incremental increase in the ability to predict all-cause and cardiac mortality, and stress TPD remained independently predictive for both all-cause and cardiac mortality in a multivariate model. ConclusionVasodilator stress (including regadenoson) MPI effectively risk stratifies patients with recently elevated cardiac biomarkers, with the increasing risk of mortality with the increasing severity of perfusion defects. It provides incremental prognostic value, in addition to clinical factors and degree of troponin elevation.

Value of ventilation/perfusion SPECT in evaluation of anticoagulant therapy for patients with pulmonary embolism and the influencing factors of treatment effect

Objective To investigate the value of pulmonary ventilation/perfusion (V/Q) SPECT in evaluation of anticoagulant therapy for patients with pulmonary embolism (PE) and identify factors which may affect the therapy. Methods From July 2014 to December 2016, sixty-three patients (23 males, 40 females, age (60±14) years), who were clinically diagnosed as PE and underwent V/Q SPECT before and after anticoagulant therapy, were recruited retrospectively in this study. According to the percentage of lung perfusion defect (PD) out of total lung volume, the patients were divided into mild ( 50%) PE groups. The lung PD decreased≥50% after anticoagulant therapy and no new PD detected was defined as the standard of effective therapy, otherwise the treatment were defined as ineffective. Data of different groups were compared. Factors that may predict the severity of PD or affect the treatment were analyzed. χ2 test and logistic regression were used for data analysis. Results PE were detected in 476 pulmonary segments and sub segments. The distribution of PE in different lung lobes had no statistically significant difference (χ2=4.995, P>0.05). More pulmonary arterial hypertension (PAH) were detected in patients with severe PE (80%, 12/15) and moderate PE (66.7%, 16/24) in comparison with patients with mild PE (41.7%, 10/24; χ2=7.062, P<0.05). The occurrence of PAH was related to the severity of PD, with odds ratio (OR) value of 2.680 (95% CI: 1.115-6.446, P<0.05). PAH was an independent risk factor for treatment effect (OR value: 3.134(95% CI: 1.341-7.324), P<0.05). Conclusions V/Q SPECT has an important value for evaluating the effect of anticoagulant therapy and guiding individual therapy. The more extent of PE involved, the higher prevalence of PAH. Anticoagulant therapy may be ineffective in PE patients with moderate or severe PAH. Key words: Pulmonary embolism; Anticoagulants; Treatment outcome; Tomography, emission-computed, single-photon; Technetium Tc 99m aggregated albumin