Prognostic Value of Left Ventricular Longitudinal Function and Myocardial Fibrosis in Patients With Ischemic and Non-Ischemic Dilated Cardiomyopathy Concomitant With Type 2 Diabetes Mellitus: A 3.0 T Cardiac MR Study.

BACKGROUND: Poorly controlled type 2 diabetes mellitus (T2DM) is known to result in left ventricular (LV) dysfunction, myocardial fibrosis, and ischemic/nonischemic dilated cardiomyopathy (ICM/NIDCM). However, less is known about the prognostic value of T2DM on LV longitudinal function and late gadolinium enhancement (LGE) assessed with cardiac MRI in ICM/NIDCM patients. PURPOSE: To measure LV longitudinal function and myocardial scar in ICM/NIDCM patients with T2DM and to determine their prognostic values. STUDY TYPE: Retrospective cohort. POPULATION: Two hundred thirty-five ICM/NIDCM patients (158 with T2DM and 77 without T2DM). FIELD STRENGTH/SEQUENCE: 3T; steady-state free precession cine; phase-sensitive inversion recovery segmented gradient echo LGE sequences. ASSESSMENT: Global peak longitudinal systolic strain rate (GLPSSR) was evaluated to LV longitudinal function with feature tracking. The predictive value of GLPSSR was determined with ROC curve. Glycated hemoglobin (HbA1c) was measured. The primary adverse cardiovascular endpoint was follow up every 3 months. STATISTICAL TESTS: Mann-Whitney U test or student's t-test; Intra and inter-observer variabilities; Kaplan-Meier method; Cox proportional hazards analysis (threshold = 5%). RESULTS: ICM/NIDCM patients with T2DM exhibited significantly lower absolute value of GLPSSR (0.39 ± 0.14 vs. 0.49 ± 0.18) and higher proportion of LGE positive (+) despite similar LV ejection fraction, compared to without T2DM. LV GLPSSR was able to predict primary endpoint (AUC 0.73) and optimal cutoff point was 0.4. ICM/NIDCM patients with T2DM (GLPSSR < 0.4) had more markedly impaired survival. Importantly, this group (GLPSSR < 0.4, HbA1c ≥ 7.8%, or LGE (+)) exhibited the worst survival. In multivariate analysis, GLPSSR, HbA1c, and LGE (+) significantly predicted primary adverse cardiovascular endpoint in overall ICM/NIDCM and ICM/NIDCM patients with T2DM. CONCLUSIONS: T2DM has an additive deleterious effect on LV longitudinal function and myocardial fibrosis in ICM/NIDCM patients. Combining GLPSSR, HbA1c, and LGE could be promising markers in predicting outcomes in ICM/NIDCM patients with T2DM. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: 5.

Dynamic changes in cardiac morphology, function, and diffuse myocardial fibrosis duration of diabetes in type 1 and type 2 diabetic mice models using 7.0 T CMR and echocardiography.

Background: Diabetes mellitus (DM) is associated with an increased risk of cardiovascular disease (CVD). Hence, early detection of cardiac changes by imaging is crucial to reducing cardiovascular complications. Purpose: Early detection of cardiac changes is crucial to reducing cardiovascular complications. The study aimed to detect the dynamic change in cardiac morphology, function, and diffuse myocardial fibrosis(DMF) associated with T1DM and T2DM mice models. Materials and methods: 4-week-old C57Bl/6J male mice were randomly divided into control (n=30), T1DM (n=30), and T2DM (n=30) groups. A longitudinal study was conducted every 4 weeks using serial 7.0T CMR and echocardiography imaging. Left ventricular ejection fraction (LV EF), tissue tracking parameters, and DMF were measured by cine CMR and extracellular volume fraction (ECV). Global peak circumferential strain (GCPS), peak systolic strain rate (GCPSSR) values were acquired by CMR feature tracking. LV diastolic function parameter (E/E') was acquired by echocardiography. The correlations between the ECV and cardiac function parameters were assessed by Pearson's test. Results: A total of 6 mice were included every 4 weeks in control, T1DM, and T2DM groups for analysis. Compared to control group, an increase was detected in the LV mass and E/E' ratio, while the values of GCPS, GCPSSR decreased mildly in DM. Compared to T2DM group, GCPS and GCPSSR decreased earlier in T1DM(GCPS 12W,P=0.004; GCPSSR 12W,P=0.04). ECV values showed a significant correlation with GCPS and GCPSSR in DM groups. Moreover, ECV values showed a strong positive correlation with E/E'(T1DM,r=0.757,P<0.001;T2DM, r=0.811,P<0.001). Conclusion: The combination of ECV and cardiac mechanical parameters provide imaging biomakers for pathophysiology, early diagnosis of cardiac morphology, function and early intervention in diabetic cardiomyopathy in the future.

Quantification of Early Diffuse Myocardial Fibrosis Through 7.0 T Cardiac Magnetic Resonance T1 Mapping in a Type 1 Diabetic Mellitus Mouse Model.

BACKGROUND: Diffuse myocardial interstitial fibrosis (DMIF) is a key factor for heart failure (HF) in diabetic cardiomyopathy. MRI T1-mapping technique can quantitatively evaluate DMIF. PURPOSE: To evaluate of early DMIF in a type 1 diabetes mellitus (T1DM) mouse model through 7.0 T MRI T1 mapping. STUDY TYPE: Prospective. ANIMAL MODEL: A total of 50 8-week-old C57Bl/6J male mice were divided into control (n = 20) and T1DM (n = 30) groups. FIELD STRENGTH/SEQUENCE: A 7.0 T small animal MRI; gradient echo Look-Locker inversion recovery T1-mapping sequence; cine MRI. Scans were acquired in control and T1DM mice every 4 weeks until 24 weeks. ASSESSMENT: End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), left ventricle (LV) mass, fractional shortening (FS), and E/A ratio. They were evaluated through echocardiography and cine MRI. The extracellular volume fraction (ECV) was calculated. Sirius Red staining was performed and calculated collagen volume fraction (CVF). STATISTICAL TESTS: Differences in ECV and CVF between two groups were analyzed using one-way analysis of variance. The correlation between ECV and CVF was assessed using Pearson's correlations. RESULTS: Compared with the control group, a progressive decrease in FS, EF, and E/A ratio was observed in the T1DM group. Both ECV and CVF values gradually increased during diabetes progression. A significant increase in ECV and CVF values was observed at 12 weeks (ECV: 32.5% ± 1.6% vs. 28.1% ± 1.8%; CVF: 6.9% ± 1.8% vs. 3.3% ± 1.1%). ECV showed a strong correlation with CVF (r = 0.856). DATA CONCLUSION: ECV is an accurate and feasible imaging marker that can be used to quantitatively assess DMIF changes over time in T1DM mice. ECV has potential to accurately detect DMIF in the early stage and may be a useful imaging tool to assess the need for early intervention in T1DM mice. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 3.

The Dynamic Characteristics of Myocardial Contractility and Extracellular Volume in Type 2 Diabetes Mellitus Mice Investigated by 7.0T Cardiac Magnetic Resonance.

Type 2 diabetes mellitus (T2DM) is associated with a high prevalence of diastolic dysfunction and congestive heart failure. A potential contributing factor is the accelerated accumulation of diffuse myocardial fibrosis and stiffness. Novel cardiac magnetic resonance (CMR) imaging techniques can identify both myocardial fibrosis and contractility quantitatively. This study aimed to investigate the dynamic characteristics of the myocardial strain and altered extracellular volume (ECV) fraction as determined by 7.0 T CMR in T2DM mice. C57Bl/6J mice were randomly divided into T2DM (fed a high-fat diet) and control (fed a normal diet) groups. They were scanned on 7.0 T MRI every 4 weeks until the end of week 24. The CMR protocol included multi-slice cine imaging to assess left ventricle strain and strain rate, and pre- and post-contrast T1 mapping images to quantify ECV. The ECV in the T2DM mice was significantly higher (p < 0.05) than that in the control group since week 12 with significantly impaired myocardial strain (p < 0.05). A significant linear correlation was established between myocardial strain and ECV (p < 0.001) and left ventricular-ejection fraction and ECV (p = 0.003). The results suggested that CMR feature tracking-derived myocardial strain analysis can assess functional abnormalities that may be associated with ECM alterations in diabetic cardiomyopathy, contributing to the study of diabetic therapy effects.

Acute type A aortic intramural hematoma and type A aortic dissection: correlation between the intimal tear features and pathogenesis.

BACKGROUND: To determine the prevalence, clinical and imaging features of intimal tear detected by ECG-gated multidetector computed tomography (MDCT) and confirmed by surgery in patients with acute type A intramural hematoma (ATAIMH) and acute type A aortic dissection (AAAD). METHODS: This retrospective study involved analysis of the intimal tear characteristics in 72 consecutive patients with ATAIMH and 209 with AAAD who were diagnosed by MDCT. The size and location of the intimal tear were measured and compared between these two groups of patients. The findings were also compared with those from 28 patients with ATAIMH who underwent surgical treatment to determine the intimal tear features as observed on CT angiography (CTA). RESULTS: Patients in the ATAIMH group were significantly older than those in the AAAD group (58.6±11.3 vs. 49.4±12.8 years, P<0.001), and females were predominant in the former category (ATAIMH vs. AAAD: 44.4% vs. 27.8%, P<0.01). Marfan syndrome and pregnancy were associated with most of the occurrences of AAAD. Sixty-four patients (88.9%) with ATAIMH were recognized as having intimal tear in the CTA images. The number of aortic segments in the ATAIMH patients was smaller than that in the AAAD patients (4.45±1.56 vs. 5.04±1.72 segments, P<0.01). The distribution of the intimal tear did not show any difference between the two groups. During the surgery, pericardial hemorrhage was observed in a higher proportion of patients in the ATAIMH than in the AAAD group (60.7% vs. 22.1%; P<0.01). In the former category, all of the intimal tears detected using CTA were confirmed during the operation, and the size was significantly larger than measured on the CTA images (6.95±5.12 vs. 19.59±6.51 mm, P<0.001). Six ATAIMH patients progressed to classical aortic dissection (AD) at surgery. CONCLUSIONS: Patients with ATAIMH have a high prevalence of intimal tear, which is significantly smaller than that measured in patients with classic AAAD. Just like AD, ATAIMH may also be triggered by intimal tear. Hence, timely surgical repair is needed.

Effect of a calcium deblooming algorithm on accuracy of coronary computed tomography angiography.

BACKGROUND: Coronary artery calcification is a significant contributor to reduced accuracy of coronary computed tomographic angiography (CTA) in the assessment of coronary artery disease severity. The aim of the current study is to assess the impact of a prototype calcium deblooming algorithm on the diagnostic accuracy of CTA. METHODS: 40 patients referred for invasive catheter angiography underwent CTA and invasive catheter angiography. The CTA were reconstructed using a standard soft tissue kernel (CTASTAND) and a deblooming algorithm (CTADEBLOOM). CTA studies were read with and without the deblooming algorithm blinded to the invasive coronary angiogram findings. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the detection of stenosis ≥50% or ≥70% were evaluated using quantitative coronary angiography as the reference standard. Image quality was assessed using a 5-point scale, and the presence of image artifact recorded. RESULTS: All studies were diagnostic with 548 segments available for evaluation. Image score was 3.64 ±â€¯0.72 with CTADEBLOOM, versus 3.56 ±â€¯0.72 with CTASTAND (p = 0.38). CTADEBLOOM had significantly less calcium blooming artifact than CTASTAND (12.5% vs. 47.5%, p = 0.001). Based on a 50% stenosis threshold for defining significant disease, the Sensitivity/Specificity/PPV/NPV/Accuracy were 65.9/84.9/27.6/96.6/83.4 for CTADEBLOOM and 75.0/81.9/26.6/97.4/81.4 for CTASTAND using a ≥50% threshold. CTADEBLOOM specificity was significantly higher than CTASTAND (84.9% vs. 81.5%, p = 0.03), with no difference between the algorithms in sensitivity (p = 0.22), or accuracy (p = 0.15). These results remained unchanged when a stenosis threshold of ≥70% was used. Interobserver agreement was fair with both techniques (CTADEBLOOM k = 0.38, CTASTAND k = 0.37). CONCLUSION: In this proof of concept study, coronary calcification deblooming using a prototype post-processing algorithm is feasible and reduces calcium blooming with an improvement of the specificity of the CTA exam.

Prediction Efficiency of Postoperative Acute Kidney Injury in Acute Stanford Type A Aortic Dissection Patients with Renal Resistive Index and Semiquantitative Color Doppler.

OBJECTIVES: This study is aimed to evaluate the efficiency in early prediction of postoperative persistent acute kidney injury (PAKI) after surgery in acute Stanford type A aortic dissection (AAAD) patients by using Doppler renal resistive index (RRI) and semiquantitative color (SQC) Doppler grade, respectively. METHODS: 84 AAAD patients received Sun's surgical management, and 67 patients were enrolled. RRI and SQC Doppler grade were evaluated by ultrasonography, respectively, at 6 hours after surgery. Serum creatinine (sCr) was recorded before operation and at 24 hours, 48 hours, and 72 hours after operation. AKI grade was evaluated according to the classifications of the Acute Kidney Injury Network (AKIN). PAKI is defined as persistent oliguria and/or sCr elevation after 3 days. RRI and SQC Doppler grade were compared, respectively, between the PAKI and non-PAKI groups. Potential predictors were first tested by univariate logistic regression analysis, and a multivariate model was identified to determine the independent predictive ability of RRI and SQC Doppler grade for the PAKI. Receiver operating characteristic (ROC) analysis was performed to compare the diagnostic accuracy between RRI and SQC Doppler grade in early prediction of PAKI by using AKIN classifications as the reference standard. RESULTS: Of a total of 67 patients enrolled during the study period, 21 (31.3%) patients suffered from PAKI and 8 (11.9%) patients required dialysis. There are significant differences in RRI (0.80 ± 0.09 vs. 0.70 ± 0.05, P=0.002) and SQC Doppler grade (x 2=12.193, P=0.007) between the 2 groups with and without PAKI. Univariate analysis showed that RRI, SQC Doppler grade, length of stay in ICU, time of CPB, and length of stay in hospital were significant predictors of PAKI. RRI and the SQC Doppler grade remained independent predictors of PAKI. Area under the curve (AUC) of RRI was 0.855 (95% CI, 0.74-0.96) with cutoff value 0.725 (sensitivity 90.9% and specificity 71.1%), AUC of SQC Doppler grade was 0.642 (95% CI, 0.49-0.79) with cutoff value grade 2 (sensitivity 50% and specificity 73.3%). CONCLUSION: Both postoperative RRI and SQC Doppler grade are independent predictors for PAKI after surgery in AAAD patients. Both postoperative RRI and SQC Doppler grade can be obtained rapidly by bedside ultrasound, which is a good tool for early prediction for postoperative PAKI.

Deep Learning for Diagnosis of Chronic Myocardial Infarction on Nonenhanced Cardiac Cine MRI.

Background Renal impairment is common in patients with coronary artery disease and, if severe, late gadolinium enhancement (LGE) imaging for myocardial infarction (MI) evaluation cannot be performed. Purpose To develop a fully automatic framework for chronic MI delineation via deep learning on non-contrast material-enhanced cardiac cine MRI. Materials and Methods In this retrospective single-center study, a deep learning model was developed to extract motion features from the left ventricle and delineate MI regions on nonenhanced cardiac cine MRI collected between October 2015 and March 2017. Patients with chronic MI, as well as healthy control patients, had both nonenhanced cardiac cine (25 phases per cardiac cycle) and LGE MRI examinations. Eighty percent of MRI examinations were used for the training data set and 20% for the independent testing data set. Chronic MI regions on LGE MRI were defined as ground truth. Diagnostic performance was assessed by analysis of the area under the receiver operating characteristic curve (AUC). MI area and MI area percentage from nonenhanced cardiac cine and LGE MRI were compared by using the Pearson correlation, paired t test, and Bland-Altman analysis. Results Study participants included 212 patients with chronic MI (men, 171; age, 57.2 years ± 12.5) and 87 healthy control patients (men, 42; age, 43.3 years ± 15.5). Using the full cardiac cine MRI, the per-segment sensitivity and specificity for detecting chronic MI in the independent test set was 89.8% and 99.1%, respectively, with an AUC of 0.94. There were no differences between nonenhanced cardiac cine and LGE MRI analyses in number of MI segments (114 vs 127, respectively; P = .38), per-patient MI area (6.2 cm2 ± 2.8 vs 5.5 cm2 ± 2.3, respectively; P = .27; correlation coefficient, r = 0.88), and MI area percentage (21.5% ± 17.3 vs 18.5% ± 15.4; P = .17; correlation coefficient, r = 0.89). Conclusion The proposed deep learning framework on nonenhanced cardiac cine MRI enables the confirmation (presence), detection (position), and delineation (transmurality and size) of chronic myocardial infarction. However, future larger-scale multicenter studies are required for a full validation. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Leiner in this issue.

Quantification of doxorubicin-induced interstitial myocardial fibrosis in a beagle model using equilibrium contrast-enhanced computed tomography: A comparative study with cardiac magnetic resonance T1-mapping.

BACKGROUND: The noninvasive equilibrium contrast-enhanced cardiac computed tomography (CCT) has potential for myocardial tissue characterization. The objective of this study was to test the feasibility of CCT-based extracellular volume (ECV) fraction in beagle models of doxorubicin-induced interstitial myocardial fibrosis, with cardiac magnetic resonance (CMR) as the reference. METHODS: This study was approved by local ethics committee. Thirteen beagles were included with ECV quantified by CCT and CMR at baseline, 16 and 24 weeks after modeling. Spearman correlation analysis was used to determine the association between CT ECV, CMR ECV, collagen volume fraction (CVF), LVEF and serum fibrosis index (Hyaluronic acid [HA], Laminin [LN] and Type-III procollagen [PCIII]). RESULTS: Median ECV values in CT and CMR at 16 and 24 weeks were significantly higher than those at baseline (CT ECV: 34.4% and 37.7% vs. 25.2%; CMR ECV: 32.2% and 37.4% vs. 22.7%; P < 0.001). A strong correlation was found between CCT and CMR for ECV (r = 0.899, P < 0.001). Both correlated well with CVF (r = 0.951 and 0.879 for CT and MR ECV vs. CVF, P < 0.001), serum fibrosis index (r = 0.830-0.907 for CT and MR ECV vs. HA, LN, PCIII, respectively, P < 0.05) and were inversely related to LVEF (r = -0.846 and -0.804 for CCT and CMR, P < 0.001). Bland-Altman analysis showed a small bias (1.5%), with 95% limits of agreement of -2.7% and 5.6%. CONCLUSIONS: CCT-derived ECV correlates well with CMR, histology and serum fibrosis index, suggesting that CCT is capable of myocardial tissue characterization.

Second-generation motion correction algorithm improves diagnostic accuracy of single-beat coronary CT angiography in patients with increased heart rate.

OBJECTIVE: To assess the effect of a second-generation motion correction algorithm on the diagnostic accuracy of coronary computed tomography angiography (CCTA) using a 256-detector row CT in patients with increased heart rates. METHODS: Eighty-one consecutive symptomatic cardiac patients with increased heart rates (≥ 75 beats per min) were enrolled. All patients underwent CCTA and invasive coronary angiography (ICA). CCTA was performed with a 256-detector row CT using prospectively ECG-triggered single-beat protocol. Images were reconstructed using standard (STD) algorithm, first-generation intra-cycle motion correction (MC1) algorithm, and second-generation intra-cycle motion correction (MC2) algorithm. The image quality of coronary artery segments was assessed by two experienced radiologists using a 4-point scale (1: non-diagnostic and 4: excellent), according to the 18-segment model. Diagnostic performance for segments with significant lumen stenosis (≥ 50%) was compared between STD, MC1, and MC2 by using ICA as the reference standard. RESULTS: The mean effective dose of CCTA was 1.0 mSv. On per-segment level, the overall image quality score and interpretability were improved to 3.56 ± 0.63 and 99.2% due to the use of MC2, as compared to 2.81 ± 0.85 and 92.5% with STD and 3.21 ± 0.79 and 97.2% with MC1. On per-segment level, compared to STD and MC1, MC2 improved the sensitivity (92.2% vs. 79.2%, 80.7%), specificity (97.8% vs. 82.1%, 90.8%), positive predictive value (89.9% vs. 48.4%, 65.1%), negative predictive value (98.3% vs. 94.9%, 95.7%), and diagnostic accuracy (96.8% vs. 81.5%, 89.0%). CONCLUSION: A second-generation intra-cycle motion correction algorithm for single-beat CCTA significantly improves image quality and diagnostic accuracy in patients with increased heart rate. KEY POINTS: • A second-generation motion correction (MC2) algorithm can further improve the image quality of all coronary arteries than a first-generation motion correction (MC1). • MC2 algorithm can significantly reduce the number of false positive segments compared to standard and MC1 algorithm.

Normal Values of Myocardial Deformation Assessed by Cardiovascular Magnetic Resonance Feature Tracking in a Healthy Chinese Population: A Multicenter Study.

Reference values on atrial and ventricular strain from cardiovascular magnetic resonance (CMR) are essential in identifying patients with impaired atrial and ventricular function. However, reference values have not been established for Chinese subjects. One hundred and fifty healthy volunteers (75 Males/75 Females; 18-82 years) were recruited. All underwent CMR scans with images acceptable for further strain analysis. Subjects were stratified by age: Group 1, 18-44 years; Group 2, 45-59 years; Group 3, ≥60 years. Feature tracking of CMR cine imaging was used to obtain left atrial global longitudinal (LA Ell) and circumferential strains (LA Ecc) and respective systolic strain rates, left ventricular longitudinal (LV Ell), circumferential (LV Ecc) and radial strains (LV Err) and their respective strain rates, and right ventricular longitudinal strain (RV Ell) and strain rate. LA Ell and LA Ecc were 32.8 ± 9.2% and 40.3 ± 13.4%, respectively, and RV Ell was -29.3 ± 6.0%. LV Ell, LV Ecc and LV Err were -22.4 ± 2.9%, -24.3 ± 3.1%, and 79.0 ± 19.4%, respectively. LV Ell and LV Ecc were higher in females than males (P < 0.05). LA Ell, LA Ecc, and LV Ecc decreased, while LV Err increased with age (P < 0.05). LV Ell and RV Ell were not shown to be associated with age. Normal ranges for atrial and ventricular strain and strain rates are provided using CMR feature tracking in Chinese subjects.

Quantitative Study of Abdominal Blood Flow Patterns in Patients with Aortic Dissection by 4-Dimensional Flow MRI.

The purpose of this study is to evaluate the hemodynamic characteristics of the true lumen (TL) and the false lumen (FL) in 16 patients with aortic dissection (AD) using 4D flow magnetic resonance imaging (MRI) and thoracic and abdominal computed tomography (CT) angiography. The quantitative parameters that were measured in the TL and FL included velocity and flow. The mean area and regurgitant fraction of the TL were significantly lesser at all four levels (p < 0.05); the average through-plane velocity, peak velocity magnitude, average net flow, peak flow, and net forward volume in the TL were considerably higher (p < 0.05). The intimal entry's size was negatively correlated with the blood flow velocity and flow rate in the TL (p < 0.05) and positively correlated with the average through-plane velocity, average net flow, and peak flow in the FL (p < 0.05); the blood flow indices in the TL were enhanced with an increase in the intimal entry numbers (p < 0.05) and the peak flow in the FL was lowered (p = 0.025); if FL thrombosis existed, the average through-plane velocity and peak velocity magnitude in the TL were substantially higher (p < 0.05). 4D flow MRI facilitates qualitative and quantitative analysis of the alterations in the abdominal aortic blood flow patterns.

Extracellular volume quantitation using dual-energy CT in patients with heart failure: Comparison with 3T cardiac MR.

BACKGROUNDS: Cardiac magnetic resonance (CMR) T1 mapping and the extracellular volume (ECV) have been developed to quantitative analysis of diffusely abnormal myocardial fibrosis (MF). However, dual-energy CT (DECT) has a potential for calculation of ECV. The aim of this study is to evaluate the feasibility and accuracy of DECT technique in determining the ECV in patients with heart failure, with 3T CMR as the reference. METHODS: Thirty-five patients with various reasons of heart failure were enrolled in this study. Both DECT and CMR exams were completed within 24 h. ECVs were calculated, and the relationship between DECT-ECV, CMR-ECV, and other heart function parameters, including left ventricular end systolic and diastolic volume, cardiac output and ejection fraction (LVESV, LVEDV, CO, LVEF), Brain natriuretic peptide (BNP) was determined. All participants gave informed consent, and the study was approved by the institutional review board. RESULTS: The median ECVs on DECT and CMR were 33% (95%CI: 32%-36%) and 30% (95%CI: 30% - 32%), respectively. A good correlation between myocardial ECV at DECT and that at CMR (r = 0.945, P < 0.001) was observed. Bland-Altman analysis between DECT and CMR showed a small bias (2.6%), with 95% limits of agreement of -0.4% and 5.6%. Interobserver agreement for ECV at DECT was excellent (ICC = 0.907). Both ECVs, for DECT and CMR, were inversely associated with LVEF and CO. CONCLUSION: DECT-based ECV could be an alternative non-invasive imaging tool for myocardial tissue characterization. However, overestimation of the extent of diffuse MF is observed with use of DECT.

Blooming Artifact Reduction in Coronary Artery Calcification by A New De-blooming Algorithm: Initial Study.

The aim of this study was to investigate the use of de-blooming algorithm in coronary CT angiography (CCTA) for optimal evaluation of calcified plaques. Calcified plaques were simulated on a coronary vessel phantom and a cardiac motion phantom. Two convolution kernels, standard (STND) and high-definition standard (HD STND), were used for imaging reconstruction. A dedicated de-blooming algorithm was used for imaging processing. We found a smaller bias towards measurement of stenosis using the de-blooming algorithm (STND: bias 24.6% vs 15.0%, range 10.2% to 39.0% vs 4.0% to 25.9%; HD STND: bias 17.9% vs 11.0%, range 8.9% to 30.6% vs 0.5% to 21.5%). With use of de-blooming algorithm, specificity for diagnosing significant stenosis increased from 45.8% to 75.0% (STND), from 62.5% to 83.3% (HD STND); while positive predictive value (PPV) increased from 69.8% to 83.3% (STND), from 76.9% to 88.2% (HD STND). In the patient group, reduction in calcification volume was 48.1 ± 10.3%, reduction in coronary diameter stenosis over calcified plaque was 52.4 ± 24.2%. Our results suggest that the novel de-blooming algorithm could effectively decrease the blooming artifacts caused by coronary calcified plaques, and consequently improve diagnostic accuracy of CCTA in assessing coronary stenosis.

Additive value of 3T cardiovascular magnetic resonance coronary angiography for detecting coronary artery disease.

BACKGROUND: The purpose of the work was to evaluate the incremental diagnostic value of free-breathing, contrast-enhanced, whole-heart, 3 T cardiovascular magnetic resonance coronary angiography (CE-MRCA) to stress/rest myocardial perfusion imaging (MPI) and late gadolinium enhancement (LGE) imaging for detecting coronary artery disease (CAD). METHODS: Fifty-one patients with suspected CAD underwent a comprehensive cardiovascular magnetic resonance (CMR) examination (CE-MRCA, MPI, and LGE). The additive diagnostic value of MRCA to MPI and LGE was evaluated using invasive x-ray coronary angiography (XA) as the standard for defining functionally significant CAD (≥ 50% stenosis in vessels > 2 mm in diameter). RESULTS: 90.2% (46/51) patients (54.0 ± 11.5 years; 71.7% men) completed CE-MRCA successfully. On per-patient basis, compared to MPI/LGE alone or MPI alone, the addition of MRCA resulted in higher sensitivity (100% vs. 76.5%, p < 0.01), no change in specificity (58.3% vs. 66.7%, p = 0.6), and higher accuracy (89.1% vs 73.9%, p < 0.01) for CAD detection (prevalence = 73.9%). Compared to LGE alone, the addition of CE-MRCA resulted in higher sensitivity (97.1% vs. 41.2%, p < 0.01), inferior specificity (83.3% vs. 91.7%, p = 0.02), and higher diagnostic accuracy (93.5% vs. 54.3%, p < 0.01). CONCLUSION: The inclusion of successful free-breathing, whole-heart, 3 T CE-MRCA significantly improved the sensitivity and diagnostic accuracy as compared to MPI and LGE alone for CAD detection.

Clinical value of patient-specific three-dimensional printing of congenital heart disease: Quantitative and qualitative assessments.

OBJECTIVE: Current diagnostic assessment tools remain suboptimal in demonstrating complex morphology of congenital heart disease (CHD). This limitation has posed several challenges in preoperative planning, communication in medical practice, and medical education. This study aims to investigate the dimensional accuracy and the clinical value of 3D printed model of CHD in the above three areas. METHODS: Using cardiac computed tomography angiography (CCTA) data, a patient-specific 3D model of a 20-month-old boy with double outlet right ventricle was printed in Tango Plus material. Pearson correlation coefficient was used to evaluate correlation of the quantitative measurements taken at analogous anatomical locations between the CCTA images pre- and post-3D printing. Qualitative analysis was conducted by distributing surveys to six health professionals (two radiologists, two cardiologists and two cardiac surgeons) and three medical academics to assess the clinical value of the 3D printed model in these three areas. RESULTS: Excellent correlation (r = 0.99) was noted in the measurements between CCTA and 3D printed model, with a mean difference of 0.23 mm. Four out of six health professionals found the model to be useful in facilitating preoperative planning, while all of them thought that the model would be invaluable in enhancing patient-doctor communication. All three medical academics found the model to be helpful in teaching, and thought that the students will be able to learn the pathology quicker with better understanding. CONCLUSION: The complex cardiac anatomy can be accurately replicated in flexible material using 3D printing technology. 3D printed heart models could serve as an excellent tool in facilitating preoperative planning, communication in medical practice, and medical education, although further studies with inclusion of more clinical cases are needed.

A Preliminary Study of Computed Tomography Coronary Angiography Within a Single Cardiac Cycle in Patients With Atrial Fibrillation Using 256-Row Detector Computed Tomography.

OBJECTIVE: The purpose of this study was to evaluate the image quality and radiation dose of computed tomography (CT) coronary angiography using a 256-row detector CT scanner in a single cardiac cycle in patients with atrial fibrillation (AF). METHODS: Seventy consecutive patients (41 men and 29 women; age range was from 37 to 84 years, mean age was 61.7 ± 10.2 years; body mass index range was from 15.08 to 36.45 kg/m, mean body mass index was 25.9 ± 3.5 kg/m) with persistent or paroxysmal AF during acquisition, who were not receiving any medications for heart rate (HR) regulation, were imaged with a 256-row detector CT scanner (Revolution CT, GE healthcare). According to the HR or HR variability (HRV) the patients were divided into 4 groups: group A (HR, ≥75 bpm; n = 36), group B (HR, <75 bpm; n = 34), group C (HRV, ≥50 bpm; n = 26), and group D (HRV, <50 bpm; n = 44). The snapshot freeze algorithm reconstruction was used to reduce motion artifacts whenever necessary. Two experienced radiologists, who were blinded to the electrocardiograph and reconstruction information, independently graded the CT images in terms of visibility and artifacts with a 4-grade rating scale (1, excellent; 2, good; 3, poor; 4, insufficient) using the 18-segment model. Subjective image quality scores and effective dose (ED) were calculated and compared between these groups. RESULTS: The HR during acquisition ranged from 47 to 222 bpm (88.24 ± 36.80 bpm). A total of 917 in 936 coronary artery segments were rated as diagnostically evaluable (98.2 ± 0.04%). There was no significant linear correlation between mean image quality and HR or HRV (P > 0.05). Snapshot freeze reconstruction technique was applied in 28 patients to reduce motion artifacts and thus showed image quality was improved from 93.2% to 98.4%. The ED was 3.05 ± 2.23 mSv (0.49-11.86 mSv) for all patients, and 3.76 ± 2.22 mSv (0.92-11.17 mSv), 2.30 ± 2.02 mSv (0.49-11.86 mSv), 3.89 ± 2.35 mSv (1.18-11.86 mSv), and 2.56 ± 2.03 mSv (0.49-11.17 mSv) for groups A, B, C, and D, respectively. There were significant differences in mean ED between groups A and B, as well as C and D (P <0.05). CONCLUSIONS: This study shows that CT coronary angiography with use of a new 256-row detector CT in single cardiac cycle achieves diagnostic image quality but with lower radiation dose in patients with AF. Heart rate or HRV has no significant effect on image quality.