Automatic calculation of myocardial perfusion reserve using deep learning with uncertainty quantification.

Background: Myocardial perfusion reserve index (MPRI) in magnetic resonance imaging (MRI) is an important indicator of ischemia, and its measurement typically involves manual procedures. The purposes of this study were to develop a fully automatic method for estimating the MPRI and to evaluate its performance. Methods: The method consisted of segmenting the myocardium in dynamic contrast-enhanced (DCE) myocardial perfusion MRI data using Monte Carlo dropout U-Net, dividing the myocardium into segments based on landmark localization with machine learning, and estimating the MPRI after the calculation of the left ventricular and myocardial contrast upslopes. The proposed method was compared with a reference method, which involved manual adjustments of the myocardial contours and upslope ranges. Results: In test subjects, MPRIs measured by the proposed technique correlated with those by the manual reference in segmental assessment [intraclass correlation coefficient (ICC) =0.75, 95% CI: 0.70-0.79, P<0.001]. The automatic and reference MPRI values showed a mean difference of -0.02 and 95% limits of agreement of (-0.86, 0.82). Conclusions: The proposed automatic method is based on deep learning segmentation and machine learning landmark detection for MPRI measurements in DCE perfusion MRI. It holds the potential to efficiently and quantitatively assess myocardial ischemia without any user's interaction.

Automated identification of myocardial perfusion defects in dynamic cardiac computed tomography using deep learning.

PURPOSE: The purpose of this study was to develop and evaluate deep convolutional neural network (CNN) models for quantifying myocardial blood flow (MBF) as well as for identifying myocardial perfusion defects in dynamic cardiac computed tomography (CT) images. METHODS: Adenosine stress cardiac CT perfusion data acquired from 156 patients having or being suspected with coronary artery disease were considered for model development and validation. U-net-based deep CNN models were developed to segment the aorta and myocardium and to localize anatomical landmarks. Color-coded MBF maps were obtained in short-axis slices from the apex to the base level and were used to train a deep CNN classifier. Three binary classification models were built for the detection of perfusion defect in the left anterior descending artery (LAD), the right coronary artery (RCA), and the left circumflex artery (LCX) territories. RESULTS: Mean Dice scores were 0.94 (±0.07) and 0.86 (±0.06) for the aorta and myocardial deep learning-based segmentations, respectively. With the localization U-net, mean distance errors were 3.5 (±3.5) mm and 3.8 (±2.4) mm for the basal and apical center points, respectively. The classification models identified perfusion defects with the accuracy of mean area under the receiver operating curve (AUROC) values of 0.959 (±0.023) for LAD, 0.949 (±0.016) for RCA, and 0.957 (±0.021) for LCX. CONCLUSION: The presented method has the potential to fully automate the quantification of MBF and subsequently identify the main coronary artery territories with myocardial perfusion defects in dynamic cardiac CT perfusion.

A Primary Neuroendocrine Tumor Mimicking a Thrombus in the Left Atrial Appendage.

Most cardiac tumors are metastases, and primary cardiac tumors are rare; even among primary cardiac tumors, primary cardiac neuroendocrine tumors (NETs) are extremely rare. Herein, we report a case of a patient presenting a left atrial mass without past medical history. Because of the location and movement of the mass, as well as the patient's cerebral infarction episode, the mass was initially suspected to be a thrombus. However, the mass was surgically diagnosed as NET.

Comparison of diagnostic performance between dynamic versus static adenosine-stress myocardial CT perfusion to detect hemodynamically significant coronary artery stenosis: A prospective multicenter study.

Myocardial computed tomography perfusion (CTP) imaging is a noninvasive method for detecting myocardial ischemia. This study aimed to compare the diagnostic performance of dynamic and static adenosine-stress CTPs for detecting hemodynamically significant coronary stenosis. We prospectively enrolled 42 patients (mean age, 59.7 ± 8.8 years; 31 males) with ≥40% coronary artery stenosis. All patients underwent dynamic CTP for adenosine stress. The static CTP was simulated by choosing the seventh dynamic dataset after the initiation of the contrast injection. Diagnostic performance was compared with invasive fractional flow reserve (FFR) <0.8 as the reference. Of the 125 coronary vessels in 42 patients, 20 (16.0%) in 16 (38.1%) patients were categorized as hemodynamically significant. Dynamic and static CTP yielded similar diagnostic accuracy (90.4% vs 88.8% using visual analysis, P = .558; 77.6% vs 80.8% using quantitative analysis, P = .534; 78.4% vs 82.4% using combined visual and quantitative analyses, P = .426). The diagnostic accuracy of combined coronary computed tomography angiography (CCTA) and dynamic CTP (89.6% using visual analysis, P = .011; 88.8% using quantitative analysis, P = .018; 89.6% using combined visual and quantitative analyses, P = .011) and that of combined CCTA and static CTP (88.8% using visual analysis, P = .018; 90.4% using quantitative analysis, P = .006; 91.2% using combined visual and quantitative analyses, P = .003) were significantly higher than that of CCTA alone (77.6%). Dynamic CTP and static CTP showed similar diagnostic performance in the detection of hemodynamically significant stenosis.

Prevalence and clinical significance of cardiovascular magnetic resonance adenosine stress-induced myocardial perfusion defect in hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is thought to be associated with microvascular dysfunction. Adenosine stress-perfusion cardiovascular magnetic resonance imaging (CMR) is a sensitive method for assessing microvascular perfusion abnormalities. We evaluated the prevalence and clinical characteristics of HCM patients with adenosine-induced perfusion defects on CMR. METHODS: Among 189 consecutive patients with HCM who underwent adenosine-stress perfusion CMR, 115 patients who had clinical, echocardiography, 24-h Holter monitoring and treadmill exercise test data were analyzed. We calculated myocardial perfusion ratio index from the intensity-over-time curve to quantify perfusion defects. The presence and extent of the stress-induced perfusion defect were compared with clinical characteristics, presence and extent of late gadolinium enhancement (LGE), left ventricular (LV) mass index and volume, presence of non-sustained ventricular tachycardia (NSVT) and results of treadmill exercise test. RESULTS: The mean age of enrolled patients was 51.8 ± 11.3 years. Most patients were asymptomatic except 25 subjects presented with New York Heart Association Class II dyspnea and 16 patients with atypical non-exertional chest discomfort. LGE was present in 103 (89.6%) subjects. Adenosine stress-induced perfusion defects were present in 48 (42%) subjects. None of the perfusion defects corresponded with a single or multiple coronary artery territories, showing a multiple patchy pattern in 24 (50.0%), a concentric subendocardial pattern in 20 subjects (41.7%), and as a single blot-like defect in the remaining 4 (8.3%). A perfusion defect was associated with NSVT, LV apical aneurysm, higher LV mass index, and higher LGE volume on univariate analysis. Multivariate analysis revealed female gender (P = 0.008), presence of apical aneurysm and NSVT (P = 0.036 and 0.047, respectively), and LV mass index (P = 0.022) to be independently associated with adenosine stress-induced perfusion defects. CONCLUSIONS: In patients with HCM, adenosine-stress perfusion defects on CMR are present in more than 40% of subjects. This perfusion defect is associated with NSVT, higher LV mass index, and apical aneurysms. The prognostic value of this finding needs further elucidation.

Comparison of tissue tracking assessment by cardiovascular magnetic resonance for cardiac amyloidosis and hypertrophic cardiomyopathy.

BACKGROUND: Administration of gadolinium-contrast can cause problems in cardiac amyloidosis (CA) patients with impaired renal function. PURPOSE: To compare patterns of cardiovascular magnetic resonance tissue tracking (CMR-TT) for CA and hypertrophic cardiomyopathy (HCM) and to assess the feasibility of CMR-TT to distinguish between these diseases without administration of gadolinium-contrast. MATERIAL AND METHODS: Included were 54 patients with biopsy-proven CA, 40 patients with HCM, and 30 healthy people. We calculated strain ratio of apex to base (SRAB) in the left ventricle (LV) using radial (R), circumferential (C), and longitudinal (L) strain from CMR-TT. The LV ejection fraction (LVEF) and the ratio of septal to posterior wall at basal level were also calculated. Late gadolinium enhancement (LGE) image analysis was performed for differential diagnosis. Area under the receiver operating characteristic curve (AUC) comparisons were used. RESULTS: All SRAB values were significantly different between CA and HCM (all P < 0.001). AUC values for parameters were 0.806 for LVEF, 0.815 for ratio of wall thickness, 0.944 for the LGE pattern, 0.898 for SRABR, 0.880 for SRABC, and 0.805 for SRABL. AUCs for the LGE pattern were significantly higher than for LVEF, ratio of wall thickness and SRABL (all P < 0.008). No significant differences were seen between AUCs for the LGE pattern, SRABR, and SRABC (all P > 0.109). CONCLUSION: SRABR and SRABC were reliable parameters for distinguishing between CA and HCM.

Coronary-to-Pulmonary Artery Fistula in Adults: Natural History and Management Strategies.

OBJECTIVE: To evaluate the natural course of coronary-to-pulmonary artery fistula (CPAF) detected on coronary computed tomography angiography (CCTA) and to propose potential treatment strategies. MATERIALS AND METHODS: In this retrospective multicenter study, we assessed the CCTA reports of 188 CPAF patients evaluated between March 2009 and June 2016. Fifty-seven patients were excluded because their follow-up (FU) periods were less than 2 years. Information regarding demographic characteristics, past history, treatment method, and the occurrence of major adverse cardiac events (MACE) during the FU period was collected. We analyzed the morphologic features of CPAF and the various factors associated with surgical treatment. Patients who had undergone FU CCTA after being diagnosed with CPAF were assessed for the presence of morphological changes on FU imaging. RESULTS: The median age of the study population was 63.0 years (range, 57.0-72.0 years), and the median FU period was 5.72 years (range, 4.08-6.96 years). The most common origin of the CPAF was both coronary arteries in 76 (58.0%) cases. An aneurysm or aneurysms was/were present in 41 (31.3%) cases. Fifty-four (41.2%) fistulas were less than 2 mm in size. Eight patients underwent surgery, and 123 (93.9%) patients received optimal medical treatment (OMT). The fistula size was significantly different between the two treatment groups (p = 0.013) and was the only factor associated with surgical treatment (odds ratio = 1.14, p = 0.021). Only one patient in the OMT group reported MACE during the FU period due to preexisting coronary artery disease. Twenty-nine patients (22.1%) underwent FU CCTA after CPAF diagnosis, with a median FU period of 3.81 years. None of the patients in the OMT group demonstrated morphological changes in the CPAF on FU imaging. CONCLUSION: Most CPAFs identified on CCTA have a favorable prognosis. Observation with OMT is usually an appropriate strategy. Fistula size is a possible determinant for surgical treatment.

Protocol using wide-detector CT with single contrast injection for the aorta and coronary artery: variable helical pitch versus volume scan following helical scan.

The aim of this study was to compare the radiation dose and image quality of two CT protocols using a wide-detector computed tomography (WDCT) scanner with single contrast injection for simultaneous evaluation of the aorta and coronary artery. We retrospectively included 104 consecutive patients who underwent coronary and aorta CT angiography. CT Protocols were divided as follows: protocol I, variable helical pitch scan (VHP, n = 31); protocol II, volume scan for coronary artery following helical scan for aorta (VFH, n = 73). Vascular attenuation, noise, signal-to-noise (SNR), and contrast-to-noise ratios (CNR) were compared. Image parameters were measured at coronary artery, thoracic aorta, abdominal aorta, and iliofemoral arteries. Subjective image quality was assessed by two observers. The patient characteristics between groups were similar (P ≥ 0.384). There were no significant differences in any of the quantitative image parameters between the two groups except for the thoracic aorta. Vascular attenuation (469.2 ± 133.6 vs. 605.9 ± 140.2 HU), CNR (24.8 ± 11.4 vs. 37.3 ± 18.5), and SNR (28.4 ± 12.0 vs. 40.6 ± 19.5 ml) were higher in the VHP protocol (P < 0.001 for each) for covering the thoracic aorta. However, all subjective image scores guaranteed diagnostic image quality. The effective radiation dose of the VFH protocol was reduced to 27.2% compared with that of the VHP protocol (443.8 ± 115.8 vs. 706.7 ± 163.7 mGy·cm, P < 0.001). WDCT with single contrast injection allows assessment of both the coronary artery and aorta. The VFH protocol can reduce the radiation dose and preserve the image quality compared with that of the VHP protocol.

Assessment of Myocardial Fibrosis Using Multimodality Imaging in Severe Aortic Stenosis: Comparison With Histologic Fibrosis.

OBJECTIVES: This study assessed diffuse myocardial fibrosis (MF) by cardiac magnetic resonance (CMR) imaging and speckle-tracking echocardiography (STE) in patients with severe aortic stenosis (AS) and validated findings by using histologic confirmation of MF. BACKGROUND: MF is a concomitant pathologic finding related to hypertrophic response in severe AS. It would be beneficial to have reliable imaging methods to assess MF. METHODS: CMR and STE were performed in 71 consecutive patients with severe AS before aortic valve replacement. The extracellular volume (ECV) and native T1 values obtained by CMR and global longitudinal strain (GLS) values by STE were measured. The degree of MF was quantified by using Masson trichrome stain in myocardial biopsy specimens obtained intraoperatively. The study population was divided into 3 groups according to the degree of MF on histology (mild, moderate, and severe MF). RESULTS: The severe MF group had a higher incidence of heart failure (HF) and diastolic dysfunction than the mild and moderate MF groups. The ECV (r = 0.465; p < 0.0001), GLS (r = 0.421; p = 0.0003), and native T1 (r = 0.429; p = 0.0002) values were significantly correlated with the degree of MF. GLS was moderately correlated with ECV (r = 0.455; p = 0.0001) and less with the native T1 (r = 0.372; p = 0.0014) value. The model using ECV (R2 = 0.44; Akaike Information Criterion [AIC] = 55.8) was found to predict the degree of MF most accurately than that with GLS (R2 = 0.35; AIC = 66.84) and the native T1 (R2 = 0.36; AIC = 66.18) value. The secondary endpoint of interest was clinical outcome of a composite of total mortality, admission for HF, or development of HF symptoms. During follow-up (median: 4.6 years), and there were 16 clinical events. Although statistically insignificant, ECV is more closely related to prediction of the clinical outcome than native T1 or GLS. CONCLUSIONS: ECV as assessed by CMR could be an ideal surrogate marker for diffuse MF in patients with severe AS among all 3 models considered.

Comparison of quantitative imaging parameters using cardiovascular magnetic resonance between cardiac amyloidosis and hypertrophic cardiomyopathy: inversion time scout versus T1 mapping.

To compare inversion time (TI) parameters, native T1, and extracellular volume (ECV) on cardiac magnetic resonance (CMR) imaging between patients with cardiac amyloidosis (CA) or hypertrophic cardiomyopathy (HCMP). Forty six patients with biopsy-confirmed CA and 30 patients with HCMP who underwent CMR were included. T1 and TI values were measured in the septum and cavity of the left ventricle on T1 mapping and TI scout images. TI values were selected at nulling point for each myocardium and blood pool. Native T1, ECV, and TI interval values were significantly different between the CA (1170.5 ± 86.4 ms, 56.7 ± 12.2, - 11.5 ± 28.4 ms) and HCMP (1059.5 ± 63.4 ms, 28.5 ± 5.8, 66.2 ± 25.4 ms) (all p < 0.001). The diagnostic performance of the TI interval (area under the ROC curve, 0.975) was not inferior to that of the ECV (0.980, p = 0.776), and it was superior to that of the native T1 (0.845, p = 0.004). The diagnostic performance of TI interval was comparable to that of ECV for differential diagnosis between CA and HCMP. TI interval showed the feasibility as quantitative CMR parameter when T1 mapping images are not available.

Association of cardiovascular risk factors on myocardial perfusion and fibrosis in asymptomatic individuals: cardiac magnetic resonance study.

Background Myocardial perfusion reserve index (MPRI) and extracellular volume fraction (ECV) on cardiac magnetic resonance (CMR) are known to quantify coronary microvascular dysfunction and myocardial fibrosis, respectively. Purpose To demonstrate that cardiovascular risk factors such as hypertension, diabetes, hyperlipidemia, and smoking are correlated with MPRI and ECV on CMR in asymptomatic individuals. Material and Methods Between October 2013 and July 2014, 196 individuals underwent CMR. After excluding those with chest pain, arrhythmia, and obstructive coronary artery disease, participants were divided into five groups: those without risk factor (n = 26) and those with one (n = 43), two (n = 35), three (n = 24), or four (n = 6) risk factors. MPRI and ECV were obtained on perfusion CMR and pre- and post-T1 mapping, respectively. Results A total of 134 asymptomatic individuals (109 men, 25 women; mean age = 54.4 ± 7.08 years; body mass index [BMI] = 24.96 ± 2.76 kg/m2; Framingham risk score [FRS] = 7.71 ± 5.21) were included. The Jonckheere-Terpstra test demonstrated trends of increasing BMI, FRS, and left ventricular mass index (all P values < 0.001), but decreasing MPRI ( P = 0.001) with increasing numbers of risk factors. Stepwise multiple linear regression demonstrated that an increasing number of cardiovascular risk factors was an independent predictor of MPRI ( P = 0.001). However, there was no significant association between the number of risk factors and ECV ( P = 0.99). Conclusion We demonstrated that an increasing number of cardiovascular risk factors is significantly associated with reduced MPRI, but not with ECV on CMR.

Natural history of spontaneous isolated celiac artery dissection after conservative treatment.

OBJECTIVE: Optimal treatment of spontaneous isolated celiac artery dissection (SICAD) is not well established because the natural history of this rare disease is poorly understood. We analyzed the natural history of patients who underwent conservative treatment. METHODS: The study included 28 patients with SICAD from December 2008 to January 2017. Our institutional policy of first-line treatment for SICAD patients was conservative, and invasive procedures were reserved for unstable complications such as severe persistent pain, significant organ malperfusion, rapid aneurysmal change, and rupture or concealed rupture. Demographics, clinical features, morphologic characteristics on computed tomography, treatment modalities, and follow-up results of these patients were retrospectively reviewed. RESULTS: Mean age was 52 years, and 89% of patients were male; 86% presented with pain, mostly abdominal, and 14% of cases were detected incidentally on abdominal imaging. None of these patients had unstable complications on admission, and all underwent initial conservative treatment. During the follow-up period (22 ± 20 months), aneurysmal change and propagation of thrombosis were noted in one patient and two patients, respectively, all of whom were managed conservatively without adverse clinical events. No difference in clinical and morphologic outcomes was noted between patients who were treated with antihypertensive therapy and those who were not. Patients with intramural hematoma on initial images showed dynamic vascular remodeling (partial to complete resorption) during the follow-up period compared with patients who had dominant intimal flap on initial images. CONCLUSIONS: The clinical course of patients with SICAD was benign. Even progressive vascular changes during follow-up did not require invasive treatment. Antihypertensive therapy might not modify the clinical course. The short-term results of conservative management are encouraging, but further evaluation with long-term follow-up in a large population is needed.

CMR assessment and clinical outcomes of hypertrophic cardiomyopathy with or without ventricular remodeling in the end-stage phase.

End-stage phase of hypertrophic cardiomyopathy (ES-HCM) is a recognized part of HCM disease spectrum. Information on cardiac magnetic resonance (CMR) studies for ES-HCM especially for those without ventricular remodeling has been limited. We aimed to evaluate the morpho-functional and tissue features of ES-HCM with or without ventricular remodeling and to explore CMR prognostic value in these patients. We analysed CMR scans of sixty-three ES-HCM patients and divided them into those with ventricular dilatation (D-ES, n = 41) and those with normal ventricular size (N-ES, n = 22). Cox proportional hazards models were used to assess the association between CMR parameters and outcomes. Patients in D-ES showed hypokinetic-dilated HCM phenotype, while patients in N-ES showed hypokinetic-restrictive HCM phenotype. LGE extent was significantly larger in D-ES (34.7% ± 15.4% vs. 22.8% ± 7.7%; P < 0.01). Atrial fibrillation and edema of lower extremity were more common in N-ES (72.7 vs. 29.3% and 54.5 vs. 24.4%, respectively; P < 0.05). Log-rank test found no significant difference between 2 groups in combined end point of cardiovascular events (χ2 = 0.66, P = 0.418). In multivariate analysis, LGE (HR 1.57-1.83 per 10% LGE increase, P < 0.01) and indexed left atrial volume (LAVI) (HR 1.14-1.21 per 20 mL/m2 increase, P < 0.05) remained independently associated with combined end point when adjusted by other risk factors. The CMR features of HCM in end-stage span between two extremes. LGE is more extensive in those with ventricular remodeling and LAVI is larger in those with normal ventricular size. Both LGE and LAVI are significant predictors of poor outcomes.

Cardioprotective Effects of Intracoronary Morphine in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: A Prospective, Randomized Trial.

BACKGROUND: A cardioprotective role of morphine acting via opioid receptors has been demonstrated, and previous preclinical studies have reported that morphine could reduce reperfusion injury and myocardial infarct size in a way similar to that of ischemic periconditioning. This study aimed to evaluate the effect of intracoronary morphine on myocardial infarct size in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention. METHODS AND RESULTS: This study was designed as a 2-center, prospective, randomized, open-label, blinded end point trial. A total of 91 ST-elevation myocardial infarction patients with thrombolysis in myocardial infarction flow grade of 0 to 1 undergoing primary percutaneous coronary intervention were randomly assigned to a morphine or control group at a 1:1 ratio. The morphine group received 3 mg of morphine sulfate diluted with 3 mL of normal saline, and the control group received 3 mL of normal saline into a coronary artery immediately after restoration of coronary flow. The primary end point was myocardial infarct size assessed by cardiac magnetic resonance imaging The cardiac magnetic resonance images were evaluated for 42 and 38 patients in the morphine and control groups, respectively. Myocardial infarct size was not different between the 2 groups (25.6±11.2% versus 24.6±10.5%, P=0.77), nor was the extent of microvascular obstruction or myocardial salvage index (6.0±6.3% versus 5.1±4.6%, P=0.91; 31.1±15.2% versus 30.3±10.9%, P=0.75, respectively). There was no difference in peak creatine kinase-MB level, final thrombolysis in myocardial infarction flow, myocardial brush grade, or complete resolution of ST-segment. CONCLUSIONS: Intracoronary morphine administration could not reduce myocardial infarct size in ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01738100.

Global quantification of left ventricular myocardial perfusion at dynamic CT imaging: Prognostic value.

BACKGROUND: There is no published data on the prognostic value of global myocardial perfusion values at stress dynamic CT myocardial perfusion imaging (CTMPI). METHODS: Data of 144 patients from 6 centers who had undergone coronary CT angiography (coronary CTA) and CTMPI were assessed. Coronary CTA studies were acquired at rest; CTMPI was performed under vasodilator stress. Coronary CTA data were evaluated for coronary artery stenosis (≥50% luminal narrowing) on a per-vessel basis. Volumes-of-interest were placed over the entire left ventricular myocardium to obtain global myocardial blood flow (MBF), myocardial blood volume (MBV), and volume transfer constant (Ktrans). Follow-up was obtained at 6/12/18 months. Major adverse cardiac events (MACE, defined as cardiac death, non-fatal myocardial infarction, unstable angina requiring hospitalization, and revascularization) served as the endpoint. RESULTS: MACE occurred in 40 patients (nonfatal myocardial infarction, n = 1, unstable angina, n = 13, PCI, n = 23, and CABG, n = 3). Patients with global MBF of <121 mL/100 mL/min were at increased risk for MACE (HR 2.07, 95% confidence interval [CI]: 1.12-3.84, p = 0.02). This association remained significant after adjusting for age, gender, and clinical risk factors (HR 2.17, 95%CI: 1.16-4.06, p = 0.02), after further adjusting for presence of ≥50% stenosis at coronary CTA (HR 2.18, 95%CI: 1.16-4.10, p = 0.02) and when excluding early (<6 months) revascularizations (HR 2.34, 95%CI: 1.01-5.43, p = 0.0486). Global MBV and Ktrans were not independent predictors of MACE. CONCLUSION: Global quantification of left ventricular MBF at stress dynamic CTMPI may have incremental predictive value for future MACE over clinical risk factors and assessment of stenosis at coronary CTA.

Triple rule-out CT angiography protocol with restricting field of view for detection of pulmonary thromboembolism and aortic dissection in emergency department patients: simulation of modified CT protocol for reducing radiation dose.

Background Triple rule-out computed tomography (TRO CT) is a CT protocol designed to simultaneously evaluate the coronary, aorta, and pulmonary arteries. Purpose To evaluate potential diagnostic performance of TRO CT with restricted volume coverage for detection of pulmonary thromboembolism (PTE) and aortic dissection (AD). Material and Methods This study included 1224 consecutive patients with acute chest pain who visited the emergency department and underwent TRO CT using a 128-slice dual-source CT. Image data were reconstructed according to the display field of view (DFOV) of coronary CT angiography (CCTA) and TRO CT protocols in each patient. The presence of PTE and AD was evaluated by independent observers in each DFOV. The radiation dose was calculated to evaluate the potential benefits by restricting z-axis coverage to cardiac scan range instead of the whole thorax. Results Among all patients, 22 cases with PTE (1.9%) and nine cases with AD (0.8%) were found. Except for one PTE case, all cases were detected on both DFOV of TRO CT and CCTA. Mean effective dose for evaluation of entire thorax and cardiac scan coverage were 5.9 ± 1.1 mSv and 3.5 ± 0.7 mSv, respectively. Conclusion Isolated PTE and AD outside the CCTA DFOV rarely occur. Therefore, modified TRO CT protocol using cardiac scan coverage can be adopted to detect PTE and AD with reduced radiation dose.

Clinical Characteristics of Marfan Syndrome in Korea.

BACKGROUND AND OBJECTIVES: Marfan syndrome (MFS) is a connective tissue disorder with autosomal dominant inheritance and a highly variable clinical spectrum. However, there are limited data available on the clinical features of Korean patients with MFS. The aim of the present study was to describe the clinical characteristics and outcomes of Korean patients with MFS. SUBJECTS AND METHODS: We included all patients who were diagnosed with MFS between January 1995 and May 2015 at a single tertiary medical center. Patients with an MFS-related disorder including MASS phenotype (myopia, mitral valve prolapse, borderline and non-progressive aortic root dilatation, skeletal findings, and striae), mitral valve prolapse syndrome, and ectopia lentis syndrome were excluded. A total of 343 Korean patients aged ≥15 years who satisfied the revised Ghent nosology were included. RESULTS: The mean patient age at diagnosis was 35.9±12.6 years and 172 (50.1%) patients were male. Median follow-up duration was 52.8 months. A total of 303 patients (88.6%) had aortic root dilatation with Z score ≥2 or aortic root dissection. Ectopia lentis was relatively less common (163 patients, 55.1%) and systemic score ≥7 was found in 217 patients (73.8%). Among 219 probands, a family history of MFS was present in 97 patients (44.5%) and sporadic cases in 121 patients (55.5%). Among the 157 probands who underwent genetic analysis, 141 (89.8%) had an FBN1 mutation associated with aortic root aneurysm/dissection. Aortic dissection (AD) or intramural hematoma (IMH) was identified in 110 patients (32.1%). Among the 221 patients without AD or IMH, descending aortic aneurysms were identified in 19 patients (8.6%). Two hundred thirteen patients (62%) underwent cardiovascular surgery of any type. Eight patients died during follow-up. CONCLUSION: We described the clinical characteristics and outcomes of Korean MFS patients. Cardiovascular manifestations were commonly detected and FBN1 mutation was present in approximately 90% of patients. In contrast, ectopia lentis was identified in approximately half of patients. Our findings will be informative for the evaluation of patients with MFS.

Triple rule-out computed tomography for risk stratification of patients with acute chest pain.

AIMS: Clinical evidence supporting triple rule-out computed tomography (TRO-CT) for rapid screening of cardiovascular disease is limited. We investigated the clinical value of TRO-CT in patients with acute chest pain. METHODS: We retrospectively enrolled 1024 patients who visited the emergency department (ED) with acute chest pain and underwent TRO-CT using a 128-slice CT system. TRO-CT was classified as "positive" if it revealed clinically significant cardiovascular disease including obstructive coronary artery disease, pulmonary thromboembolism, or acute aortic syndrome. The clinical endpoint was occurrence of a major adverse cardiovascular event (MACE) within 30 days, defined by a composite of all cause death, myocardial infarction, revascularization, major cardiovascular surgery, or thrombolytic therapy. Clinical risk scores for acute chest pain including TIMI, GRACE, Diamond-Forrester, and HEART were determined and compared to the TRO-CT findings. RESULTS: TRO-CT revealed clinically significant cardiovascular disease in 239 patients (23.3%). MACE occurred in 119 patients (49.8%) with positive TRO-CT and in 7 patients (0.9%) with negative TRO-CT (p < 0.001). Sensitivity, specificity, positive predictive value, and negative predictive value of TRO-CT was 95%, 88%, 54%, and 99%, respectively. TRO-CT was a better discriminator between patients with vs. without events as compared to clinical risk scores (c-statistics = 0.91 versus 0.64 to 0.71; integrated discrimination improvement = 0.31 to 0.37; p < 0.001 for all comparisons). Patients with a negative TRO-CT showed shorter ED stay times and admission rates compared to patients with positive TRO-CT, irrespective of clinical risk scores (p < 0.001 for all comparisons). CONCLUSION: Triple rule-out CT has high predictive performance for 30-day MACE and permits rapid triage and low admission rates irrespective of clinical risk scores.

Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension: Insights from a multicenter registry.

BACKGROUND: To identify patients with early signs of myocardial perfusion reduction, a reference base for perfusion measures is needed. OBJECTIVE: To analyze perfusion parameters derived from dynamic computed tomography perfusion imaging (CTPI) in patients with suspected coronary artery disease (CAD), and relationship with risk factors. METHODS: In this multicenter study, coronary CT angiography (cCTA) and dynamic CTPI were performed by second-generation dual-source CT in patients suspected of CAD. Risk factors were collected from hospital records. Patients with visual perfusion defects on CTPI, previous coronary intervention, or missing risk factor details were excluded. This analysis included 98 patients (mean age ± standard deviation [SD], 59.0 ± 8.6yrs; 73 male). Global measures of left ventricular myocardial blood flow (MBF), myocardial blood volume (MBV) and volume transfer constant (K(trans)) were calculated. RESULTS: Mean MBF was 139.3 ± 31.4 mL/100 mL/min, MBV 19.1 ± 2.7 mL/100 mL, and Ktrans 85.0 ± 17.5 mL/100 mL/min. No significant differences in perfusion parameters were found by gender or age category. Hypertension and diabetes mellitus resulted in lower perfusion parameters (hypertension vs normotension: MBV 18.5 ± 3.0 vs 19.7 ± 2.3 mL/100 mL and K(trans) 82.0 ± 18.0 vs 89.0 ± 16.0, p < 0.05; diabetes vs no diabetes: MBF 128.5 ± 31.5 vs 144.0 ± 30.5 mL/100 mL/min and MBV 17.9 ± 2.4 vs 19.4 ± 2.8 mL/100 mL, p < 0.05). In patients with hyperlipidemia, MBF was higher (146.8 ± 34.4 vs 130.7 ± 24.3 mL/100 mL/min, p < 0.05). Smoking and family history did not show perfusion parameter differences. CONCLUSIONS: Dynamic CTPI identifies early perfusion disturbances in conditions like diabetes and hypertension. With further standardization, absolute perfusion measures may improve CAD risk stratification in patients without visual perfusion defects.

Coronary artery calcium scores and cardiovascular risk factors in 31,545 asymptomatic Korean adults.

The aims of this study were to identify the distribution of coronary artery calcium score (CACS) by age group and cardiovascular (CV) risk factors and to evaluate the association between CV risk factors and CACS classification in asymptomatic adults. The study included 31,545 asymptomatic Koreans, over 20 years of age with no previous history of malignancy, proven coronary artery disease, or stroke, who underwent CACS computed tomography at the Health Promotion Center, Samsung Medical Center, between January 2005 and June 2013. Mean (±SD) age was 53.8 (±8.5) years overall, 56.1 (±8.3) in men, and 53.3 (±8.5) in women. They were classified into five groups based on their resting CACS: none (CAC = 0), minimal (0 < CAC ≤ 10), mild (10 < CAC ≤ 100), moderate (100 < CAC ≤ 400), and extensive (400 > CAC). Older age groups exhibited higher CACS values. The proportion of CACS classification in our study was 55.5 % with no CACS, 9.5 % with minimal CACS, 19.8 % with mild CACS, 10.8 % with moderate CACS, and 4.3 % with extensive CACS. Adjusted odds ratios (ORs) were calculated for CV risk factors to determine their association with CACS. When analyzed according to sex, in males, the adjusted OR for CACS increased with the presence of hypertension (HT), diabetes mellitus (DM), obesity, chronic kidney disease, and smoking status. While, in females, the adjusted OR for CACS increased with the presence of HT, DM, and obesity. CV risk factors appear to be significantly associated with CACS in the Korean population.