Yining Wang

Adenosine-stress dynamic myocardial perfusion imaging with second-generation dual-source CT: comparison with conventional catheter coronary angiography and SPECT nuclear myocardial perfusion imaging.

OBJECTIVE The purpose of this article is to evaluate the feasibility of adenosine-stress dynamic myocardial perfusion imaging (MPI) with 128-MDCT dual-source CT for detecting myocardial ischemia in comparison with conventional catheter coronary angiography and nuclear MPI. SUBJECTS AND METHODS Thirty patients (21 men and nine women; mean [± SD] age, 59.2 ± 7.6 years) prospectively underwent a combined stress CT perfusion and CT angiography (CTA) examination. Complete time-attenuation curves of the myocardium were acquired with prospectively ECG-triggered axial images at two alternating positions. Myocardial blood flow (MBF) was quantified according to dynamic CT perfusion, and MBF values of normal and abnormal segments were compared. Findings on CT perfusion were compared with those for stress and rest SPECT. Perfusion defects according to CT were correlated to flow-obstructing stenosis detected on CTA and catheter coronary angiography. RESULTS On stress CT perfusion, 19 patients (63%) and 83 of 504 segments (16%) had perfusion abnormalities. There was a significant difference in MBF values between normal (142.9 ± 30.6 mL/100 mL/min) and hypoperfused (90.0 ± 22.8 mL/100 mL/min) segments (p < 0.001). With nuclear MPI results as a comparison, the sensitivity, specificity, positive predictive value, and negative predictive value of CT perfusion for identifying segments with perfusion defects were 0.85, 0.92, 0.55, and 0.98, respectively. On a per-vessel basis, sensitivity, specificity, positive predictive value, and negative predictive value for detecting flow-obstructing stenosis were, respectively, 1.00, 0.757, 0.541, and 1.00 for CT perfusion; 0.90, 0.514, 0.346, and 0.947 for CTA; and 0.90, 0.814, 0.581, and 0.966 for CT perfusion combined with CTA. CONCLUSION Adenosine-stress CT perfusion detects myocardial perfusion defects in good correlation with nuclear MPI. CT perfusion combined with CTA improves the diagnostic accuracy for identifying flow-obstructing stenosis compared with CTA alone.

Global Quantification of Left Ventricular Myocardial Perfusion at Dynamic CT: Feasibility in a Multicenter Patient Population

OBJECTIVE The purpose of this study was to determine the feasibility of global quantitative measurements of left ventricular myocardial perfusion derived from stress dynamic CT myocardial perfusion imaging. MATERIALS AND METHODS The coronary CT angiographic and CT myocardial perfusion imaging datasets of 146 patients were visually evaluated for the presence of coronary artery stenosis and perfusion defects. For the quantitative analysis, volumes of interest were defined over the entire left ventricular myocardium to obtain global myocardial blood flow (MBF), myocardial blood volume (MBV), and volume transfer constant (K(trans)). RESULTS In patients without anatomically significant coronary stenosis or perfusion defects, the mean value of global MBF was 137.9 ± 28.8 mL/100 mL/min; MBV, 19.5 ± 2.3 mL/100 mL; and K(trans), 85.8 ± 15.2 mL/100 mL/min. In patients with perfusion defects in one, two, or three vessels, the mean global MBF values were 132.6 ± 29.2, 117.4 ± 4.9, and 92.5 ± 11.2 mL/100 mL/min; MBV, 17.9 ± 3.2, 16.1 ± 3.1, and 12.8 ± 1.7 mL/100 mL; and K(trans), 80.4 ± 12.9, 76.6 ± 13.8, and 72.6 ± 15.5 mL/100 mL/min. In patients with significant (> 50%) stenosis in one, two, or three vessels at coronary CT angiography, the mean global MBF values were 129.2 ± 28.3, 120.5 ± 24.2, and 119.4 ± 33.5 mL/100 mL/min; MBV, 17.8 ± 3.3, 17.2 ± 3.2, and 14.7 ± 4.1 mL/100 mL; and K(trans), 80.3 ± 12.9, 76.0 ± 14.7, and 77.6 ± 13.2 mL/100 mL/min. CONCLUSION Global quantitative assessment of left ventricular perfusion with stress dynamic CT myocardial perfusion imaging is feasible, and the findings correlate with the visual assessment of perfusion and the presence of coronary artery stenosis at coronary CT angiography. The potential clinical utility of this technique as a diagnostic tool for differentiating normal from globally reduced myocardial perfusion or as a prognostic marker merits further investigation.

Absolute Versus Relative Myocardial Blood Flow by Dynamic CT Myocardial Perfusion Imaging in Patients With Anatomic Coronary Artery Disease

OBJECTIVE The purpose of this study was to evaluate differences in the diagnostic accuracy of absolute and relative territorial myocardial blood flow (MBF) derived from stress dynamic CT myocardial perfusion imaging (MPI) for the detection of significant coronary artery stenosis. MATERIALS AND METHODS Dynamic CT MPI and coronary CT angiography (CTA) datasets from a multicenter registry of 137 patients (mean age, 60.9 ± 8.4 years; 88 men) with suspected or known coronary artery disease were retrospectively analyzed. For each coronary territory, absolute MBF and the MBF relative to remote myocardium (MBF ratio) were calculated. Coronary CTA datasets were visually assessed for significant stenosis (≥ 50% luminal narrowing) in consensus by two observers. RESULTS Significant stenosis was detected in 137 of 411 (33.3%) vessels. Mean absolute MBF and MBF ratio were statistically significantly lower in territories supplied by arteries with stenosis (80.7 ± 33.7 vs 140.0 ± 38.4 mL/100 mL/min and 0.52 vs 0.89, respectively; both p < 0.0001). ROC analysis showed better discrimination by MBF ratio than by absolute MBF (AUC, 0.925 vs 0.882; p = 0.0022) and increased sensitivity (90.7% vs 82.4%; p < 0.04) and specificity (93.1% vs 80.5%; p < 0.03) for MBF ratio and absolute MBF cutoff values of 0.71 or less and 103 mL/100 mL/min or less, respectively. CONCLUSION In stress dynamic CT MPI, relative MBF provides superior diagnostic accuracy compared with absolute territorial MBF values for coronary CTA-detected significant coronary artery stenosis.

Prevalence and types of coronary to pulmonary artery fistula in a Chinese population at dual-source CT coronary angiography

Background Coronary to pulmonary artery fistula (CPAF) is rare; reports on the prevalence and types of CPAF in a large cohort of patients are scarce. Purpose To analyze the prevalence and types of CPAF on computed tomography coronary angiography (CTCA) in a large Chinese population. Material and Methods CTCA data of 58,533 patients from five Chinese tertiary referral medical centers were retrospectively studied. The prevalence, origin, aneurysmal sac, fistula tracts, and extracardiac communication of CPAF were recorded. CTCA findings were compared with conventional coronary angiography when possible. Results Ninety-nine patients had CPAF (prevalence of 0.17%). Of the 99 CPAF cases, fistulas were found to originate from either both coronary arteries in 52 patients or from one coronary artery (33 cases from the left and 14 cases from the right coronary artery). Ten CPAF patients were complicated with the communication of extracardiac arteries. Fifteen (15.2%) CPAF patients had aneurysmal sac formation. Thirty (30.3%) patients had a single fistula tract, while 69 (69.7%) patients had multiple fistula tracts. CTCA findings in 16 patients were similar to those at DSA. Conclusion Based on this large cohort, the prevalence of CPAF in the Chinese population is about 0.17%, with origin from either the left or right coronary artery or from both. CTCA can clearly visualize the types, abnormal vascular tracts, and aneurysmal sac formation of CPAF.

Semiautomated Global Quantification of Left Ventricular Myocardial Perfusion at Stress Dynamic CT:: Diagnostic Accuracy for Detection of Territorial Myocardial Perfusion Deficits Compared to Visual Assessment

RATIONALE AND OBJECTIVES To evaluate the diagnostic accuracy of semiautomated global quantification of left ventricular myocardial perfusion derived from stress dynamic computed tomography myocardial perfusion imaging (CTMPI) for detection of territorial perfusion deficits (PD). MATERIALS AND METHODS Dynamic CTMPI datasets of 71 patients were analyzed using semiautomated volume-based software to calculate global myocardial blood flow (MBF), myocardial blood volume, and volume transfer constant. Optimal cutoff values to assess the diagnostic accuracy of these parameters for detection of one- to three-vessel territories with PD in comparison to visual analysis were calculated. RESULTS Nonsignificant differences (P = 0.694) were found for average global MBF in patients without PD and single-territorial PD. Significant differences were found for mean global MBF in patients with PD in two (P < 0.0058) and three territories (P < 0.0003). Calculated optimal thresholds for global MBF and myocardial blood volume resulted in a sensitivity, specificity, and negative predictive value of 100% for detection of three-vessel territory PD. For detection of ≥2 territories with PD, global MBF was superior to other parameters (sensitivity 81.3%, specificity 90.9%, and negative predictive value 94.3%). CONCLUSIONS Semiautomated global quantification of left ventricular MBF during stress dynamic CTMPI shows high diagnostic accuracy for detection of ≥2 vessel territories with PD, facilitating identification of patients with multi-territorial myocardial PD.

Prognostic Value of Stress Dynamic Myocardial Perfusion CT in a Multicenter Population With Known or Suspected Coronary Artery Disease.

OBJECTIVE The purpose of this study was to determine the prognostic value of myocardial perfusion CT for major adverse cardiac events (MACE). MATERIALS AND METHODS Data from six centers in Asia, Europe, and North America on 144 patients with known or suspected coronary artery disease who had undergone coronary CT angiography (CCTA) and dynamic myocardial perfusion CT with a dual-source CT system were analyzed. CCTA studies were acquired at rest. Dynamic myocardial perfusion CT was performed under vasodilator stress. CCTA data were evaluated for the presence of coronary artery stenosis (≥ 50% luminal narrowing) on a per-vessel basis. Myocardial perfusion CT data were qualitatively evaluated for perfusion defects in each vessel territory. Patient follow-up was performed 6, 12, and 18 months after imaging. The prognostic value of CT findings was assessed with Kaplan-Meier statistics and the multivariate Cox proportional hazards regression model. RESULTS According to the CCTA findings, 62 of 144 patients (43.1%) had at least one 50% or greater stenosis. According to the myocardial perfusion CT findings, 51 patients (35.4%) had one or more perfusion defects. Patients with at least one perfusion defect at myocardial perfusion CT were at increased risk of MACE (hazard ratio, 2.50; 95% CI, 1.34-4.65; p = 0.0040). This association remained significant after adjustment for age, sex, and clinical risk factors (hazard ratio, 2.41; 95% CI, 1.28-4.51; p = 0.0064) and after further adjustment for CCTA findings (hazard ratio, 2.03; 95% CI, 1.04-3.97; p = 0.0390). The number of territories with perfusion defects was strongly predictive of MACE with adjusted hazard ratios of 1.41, 3.44, and 4.76 for one, two, and three affected territories. CONCLUSION In assessment for future MACE, myocardial perfusion CT has incremental predictive value over clinical risk factors and detection of coronary artery stenosis with CCTA.

Feasibility of low-dose contrast medium high pitch CT angiography for the combined evaluation of coronary, head and neck arteries.

Purpose To evaluate the image quality and radiation dose of combined heart, head, and neck CT angiography (CTA) using prospectively electrocardiography (ECG)-triggered high-pitch spiral scan protocol, compared with single coronary CTA. Materials and Methods 151 consecutive patients were prospectively included and randomly divided into three groups. Group 1 (n = 47) underwent combined heart, neck, and head CTA using prospectively ECG-triggered high-pitch spiral (Flash) scan protocol with a single-phase intravenous injection of iodinated contrast and saline flush; Group 2 (n = 51) underwent single coronary CTA with Flash scan protocol; and Group 3 (n = 53) underwent single coronary CTA with prospective sequence scan protocol. All patients were examined on a dual source CT (Definition FLASH). The image quality was determined for each CT study. Results Patients of scanning protocol Group 1, 2, and 3 showed no significant differences in age, sex, heart rates, and BMI. Evaluation of coronary artery image quality showed comparable results in the three scanning protocol groups on a per patient-based analysis. In group 1, image quality was found to be sufficient to be diagnostic in all arterial segments of carotid arteries. The mean dose-length product (DLP) for group 1 was 256.3±24.5 mGy×cm and was significantly higher in comparison with group 2 (93.4±19.9 mGy×cm; p < 0.001). However, there was no significant difference of DLP between group 1 and group 3 (254.1±69.9 mGy×cm). Conclusions The combined heart, neck, and head arteries scan using prospectively electrocardiography (ECG)-triggered high-pitch spiral scan protocol in 1 single examination resulted in an excellent opacification of the aorta, the carotid arteries, and the coronary arteries and provided a good image quality with low radiation dose.

Early diagnosis and follow-up of chronic active Epstein-Barr-virus-associated cardiovascular complications with cardiovascular magnetic resonance imaging: A case report.

Introduction: Chronic active Epstein–Barr virus (EBV) infection (CAEBV) is characterized as chronic or recurrent mononucleosis-like symptoms and elevated EBV deoxyribonucleic acid (EBV-DNA) copies. Cardiovascular complications have high morbidity and mortality. The treatment regimen for CAEBV has not been established yet, resulting in poor prognoses. Herein, we present a case of cardiovascular magnetic resonance imaging (CMRI) evaluation with a series of sequences for CAEBV-associated cardiovascular involvement, which has never been reported. Case presentation: A 16-year-old female (body weight, 55 kg) developed a persistent fever and a positive EBV-DNA level of 28,000 copies/mL. Computed tomography angiography (CTA) showed aneurysms involving the aorta and its major branches, as well as multiple aneurysms and stenoses of the coronary arteries. CMRI of the coronary arteries depicted the dilution and stenosis of the arterial lumen as well as the thickening of the arterial wall. Late gadolinium enhancement (LGE) showed subendocardial and transmural delayed enhancement of the left ventricle, suggesting myocardial infarction. CAEBV and associated cardiovascular complications were diagnosed. After treatment with Medrol and Leflunomide, the clinical manifestation and serological parameters reversed to normal. However, the EBV-DNA level increased again to 13,900 copies/mL 2 months later. A follow-up with aorta CTA showed that the arterial walls of the bilateral common iliac artery aneurysms were thicker with new-onset mural thrombi. The aorta CTA also showed new-onset occlusion of the right coronary artery, but a follow-up of CMRI at the same day did not find new-onset delayed enhancement lesion. Conclusion: This case reminds clinicians of the vital importance of early diagnosis and close follow-up of CAEBV-associated cardiovascular complications. With cine imaging, coronary artery imaging, LGE imaging, and other novel techniques, CMRI can effectively and comprehensively reveal the early and dynamic changes, and act as an important tool in the field of cardiovascular diseases.

128-slice Dual-source Computed Tomography Coronary Angiography in Patients with Atrial Fibrillation: Image Quality and Radiation Dose of Prospectively Electrocardiogram-triggered Sequential Scan Compared with Retrospectively Electrocardiogram-gated Spiral Scan.

Objective To evaluate the image quality (IQ) and radiation dose of 128-slice dual-source computed tomography (DSCT) coronary angiography using prospectively electrocardiogram (ECG)-triggered sequential scan mode compared with ECG-gated spiral scan mode in a population with atrial fibrillation. Methods Thirty-two patients with suspected coronary artery disease and permanent atrial fibrillation referred for a second-generation 128-slice DSCT coronary angiography were included in the prospective study. Of them, 17 patients (sequential group) were randomly selected to use a prospectively ECG-triggered sequential scan, while the other 15 patients (spiral group) used a retrospectively ECG-gated spiral scan. The IQ was assessed by two readers independently, using a four-point grading scale from excel-lent (grade 1) to non-assessable (grade 4), based on the American Heart Association 15-segment model. IQ of each segment and effective dose of each patient were compared between the two groups. Results The mean heart rate (HR) of the sequential group was 96±27 beats per minute (bpm) with a variation range of 73±25 bpm, while the mean HR of the spiral group was 86±22 bpm with a variationrange of 65±24 bpm. Both of the mean HR (t=1.91, P=0.243) and HR variation range (t=0.950, P=0.350) had no significant difference between the two groups. In per-segment analysis, IQ of the sequential group vs. spiral group was rated as excellent (grade 1) in 190/244 (78%) vs. 177/217 (82%) by reader1 and 197/245 (80%) vs. 174/214 (81%) by reader2, as non-assessable (grade 4) in 4/244 (2%) vs. 2/217 (1%) by reader1 and 6/245 (2%) vs. 4/214 (2%) by reader2. Overall averaged IQ per-patient in the sequential and spiral group showed equally good (1.27±0.19 vs. 1.25±0.22, Z=-0.834, P=0.404). The effective radiation dose of the sequential group reduced significantly compared with the spiral group (4.88±1.77 mSv vs. 10.20±3.64 mSv; t=-5.372, P=0.000). Conclusion Compared with retrospectively ECG-gated spiral scan, prospectively ECG-triggered sequential DSCT coronary angiography provides similarly diagnostically valuable images in patients with atrial fibrillation and significantly reduces radiation dose.

Dual-layer spectral detector CT monoenergetic reconstruction improves image quality of non-contrast cerebral CT as compared with conventional single energy CT

PURPOSE To investigate and compare image quality of monoenergetic reconstructions from spectral NCCT to conventional 120 kVp images acquired at a similar dose. MATERIALS AND METHODS Patients undergoing NCCT on a dual-layer spectral detector CT (n = 30) and a conventional CT (n = 30) were enrolled in the study. The spectral detector CT data was reconstructed at monoenergetic images from 40 to 140 keV in 5-keV increments and 65-70 keV in 1-keV increments (Group A1) and using single energy CT equivalent reconstruction (Group A2). The reference conventional 120kVp images (Group B) were acquired using a standard-of-care protocol with the same radiation dose. We evaluated the image quality of monoenergetic images and determined the optimal keV level using HU attenuation, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), artifact evaluation in posterior fossa by placing region-of-interest (ROI) and subjective image score by 2 radiologists independently using a 4-point scale (1-excellent, 4-undiagnostic). RESULTS The SNR and subjective image score were optimal at 66-70keV, while monoenergetic 68 keV images with a higher SNR (18.48 ± 1.94, 15.55 ± 1.56 and 14.33 ± 1.38 for Group 68keV, A2 and B respectively, p < 0.001), CNR (4.09 ± 0.65, 3.43 ± 0.56 and 3.52 ± 0.55 for Group 68keV, A2 and B respectively, p < 0.001) and a lower noise (1.80 ± 0.19, 2.11 ± 0.19 and 2.25 ± 0.25 for Group 68keV, A2 and B respectively, p < 0.001). CONCLUSION Spectral NCCT monoenergetic reconstructions at 68 keV improve image quality and reduce artifact compared to conventional single energy CT without radiation dose penalty.