OBJECTIVES: The aim of this study was to examine the performance of a convolutional neural network (CNN) combined with exponentiating each pixel value in classifying benign and malignant lung nodules on computed tomography (CT) images. MATERIALS AND METHODS: Images in the Lung Image Database Consortium-Image Database Resource Initiative (LIDC-IDRI) were analyzed. Four CNN models were then constructed to classify the lung nodules by malignancy level (malignancy level 1 vs. 2, malignancy level 1 vs. 3, malignancy level 1 vs. 4, and malignancy level 1 vs. 5). The exponentiation method was applied for exponent values of 1.0 to 10.0 in increments of 0.5. Accuracy, sensitivity, specificity, and area under the curve of receiver operating characteristics (AUC-ROC) were calculated. These statistics were compared between an exponent value of 1.0 and all other exponent values in each model by the Mann-Whitney U-test. RESULTS: In malignancy 1 vs. 4, maximum test accuracy (MTA; exponent value = 2.0, 3.0, 3.5, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, and 10.0) and specificity (6.5, 7.0, and 9.0) were improved by up to 0.012 and 0.037, respectively. In malignancy 1 vs. 5, MTA (6.5 and 7.0) and sensitivity (1.5) were improved by up to 0.030 and 0.0040, respectively. CONCLUSIONS: The exponentiation method improved the performance of the CNN in the task of classifying lung nodules on CT images as benign or malignant. The exponentiation method demonstrated two advantages: improved accuracy, and the ability to adjust sensitivity and specificity by selecting an appropriate exponent value. CLINICAL RELEVANCE STATEMENT: Adjustment of sensitivity and specificity by selecting an exponent value enables the construction of proper CNN models for screening, diagnosis, and treatment processes among patients with lung nodules. KEY POINTS: • The exponentiation method improved the performance of the convolutional neural network. • Contrast accentuation by the exponentiation method may derive features of lung nodules. • Sensitivity and specificity can be adjusted by selecting an exponent value.

This prospective study aimed to evaluate whether radiation (RT)-induced myocardial damage by cardiac magnetic resonance (CMR) imaging could be a predictor of cardiac events after chemoradiotherapy (CRT) for esophageal cancer and determine the dose-volume histogram (DVH) parameters of the left ventricle (LV) in predicting cardiac events. CMR imaging was performed before and 6 months after CRT in patients receiving definitive CRT. RT-induced myocardial damage was defined as abnormal CMR findings indicating myocardial fibrosis corresponding to an isodose line of ≥30 Gy. The cutoff values of the LV DVH parameters were calculated using the receiver operating characteristic curve based on the presence of RT-induced myocardial damage. The prognostic factors related to cardiac events of Grade 3 or higher were examined. Twenty-three patients were enrolled in the study. RT-induced myocardial damage by late gadolinium enhancement and/or an increase of 100 ms or higher in native T1 post-CRT was detected in 10 of the 23 patients. LV V45 was the best predictive factor for RT-induced myocardial damage with a cutoff value of 2.1% and an area under the curve of 0.75. The median follow-up period was 82.1 months. The 5- and 7-year cumulative incidences of cardiac events of Grade 3 or higher were 14.7 and 22.4%, respectively. RT-induced myocardial damage and LV V45 were significant risk factors (P = 0.015 and P = 0.013, respectively). RT-induced myocardial damage is a significant predictor of cardiac events. LV V45 is associated with RT-induced myocardial damage and subsequent cardiac events.

Fractional flow reserve (FFR) is currently considered as the gold standard for revascularization decision-making in patients with stable coronary artery disease (CAD). The application of computational fluid dynamics to coronary computed tomography (CT) angiography (CCTA) enables calculation of FFR without additional testing, radiation exposure, contrast medium injection, and hyperemia (FFRCT). Although multiple diagnostic and clinical studies have enriched the scientific evidence, it is still challenging to integrate FFRCT into clinical practice. Both meticulous scientific backgrounds and precise anatomical data derived from CCTA are fundamental for FFRCT computation, and there are numerous factors impacting on FFRCT calculation and interpretation: coronary artery stenosis, calcium, atherosclerosis, luminal volume, and left ventricular myocardial mass. Further, there is a gap that clinicians using FFRCT need to recognize in interpretation of FFRCT results between diagnostic studies and clinical studies. In this review, we summarize multiple evidence related to FFRCT computation and interpretation to refine the FFRCT strategy in patients with stable CAD.

BACKGROUND: The relationship between body size and cardiovascular events is complex. This study utilized the ADVANCE (Assessing Diagnostic Value of Noninvasive FFRCT in Coronary Care) Registry to investigate the association between body mass index (BMI), coronary artery disease (CAD), and clinical outcomes. METHODS: The ADVANCE registry enrolled patients undergoing evaluation for clinically suspected CAD who had >30% stenosis on cardiac computed tomography angiography. Patients were stratified by BMI: normal <25 kg/m2, overweight 25-29.9 kg/m2, and obese ≥30 kg/m2. Baseline characteristics, cardiac computed tomography angiography and computed tomography fractional flow reserve (FFRCT), were compared across BMI groups. Adjusted Cox proportional hazards models assessed the association between BMI and outcomes. RESULTS: Among 5014 patients, 2166 (43.2%) had a normal BMI, 1883 (37.6%) were overweight, and 965 (19.2%) were obese. Patients with obesity were younger and more likely to have comorbidities, including diabetes and hypertension (all P<0.001), but were less likely to have obstructive coronary stenosis (65.2% obese, 72.2% overweight, and 73.2% normal BMI; P<0.001). However, the rate of hemodynamic significance, as indicated by a positive FFRCT, was similar across BMI categories (63.4% obese, 66.1% overweight, and 67.8% normal BMI; P=0.07). Additionally, patients with obesity had a lower coronary volume-to-myocardial mass ratio compared with patients who were overweight or had normal BMI (obese BMI, 23.7; overweight BMI, 24.8; and normal BMI, 26.3; P<0.001). After adjustment, the risk of major adverse cardiovascular events was similar regardless of BMI (all P>0.05). CONCLUSIONS: Patients with obesity in the ADVANCE registry were less likely to have anatomically obstructive CAD by cardiac computed tomography angiography but had a similar degree of physiologically significant CAD by FFRCT and similar rates of adverse events. An exclusively anatomic assessment of CAD in patients with obesity may underestimate the burden of physiologically significant disease that is potentially due to a significantly lower volume-to-myocardial mass ratio.

Until recently, coronary revascularization with coronary artery bypass grafting or percutaneous coronary intervention has been regarded as the standard choice for stable coronary artery disease (CAD), particularly for patients with a significant burden of ischemia. However, in conjunction with remarkable advances in adjunctive medical therapy and a deeper understanding of its long-term prognosis from recent large-scale clinical trials, including ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches), the approach to stable CAD has changed drastically. Although the updated evidence from recent randomized clinical trials will likely modify the recommendations for future clinical practice guidelines, there are still unresolved and unmet issues in Asia, where prevalence and practice patterns are markedly different from those in Western countries. Herein, the authors discuss perspectives on: 1) assessing the diagnostic probability of patients with stable CAD; 2) application of noninvasive imaging tests; 3) initiation and titration of medical therapy; and 4) evolution of revascularization procedures in the modern era.

Chronic thromboembolic pulmonary hypertension (CTEPH), classified as group 4 pulmonary hypertension (PH), is caused by stenosis and obstruction of the pulmonary arteries by organized thrombi that are incompletely resolved after acute pulmonary embolism. The prognosis of patients with CTEPH is poor if untreated; however, in expert centers with multidisciplinary teams, a treatment strategy for CTEPH has been established, dramatically improving its prognosis. CTEPH is currently not a fatal disease and is the only curable form of PH. Despite these advances and the establishment of treatment approaches, early diagnosis is still challenging, especially for non-experts, for several reasons. One of the reasons for this is insufficient knowledge of the various diagnostic imaging modalities, which are essential in the clinical practice of CTEPH. Imaging modalities should detect the following pathological findings: lung perfusion defects, thromboembolic lesions in pulmonary arteries, and right ventricular remodeling and dysfunction. Perfusion lung scintigraphy and catheter angiography have long been considered gold standards for the detection of perfusion defects and assessment of vascular lesions, respectively. However, advances in imaging technology of computed tomography and magnetic resonance imaging have enabled the non-invasive detection of these abnormal findings in a single examination. Cardiac magnetic resonance (CMR) is the gold standard for evaluating the morphology and function of the right heart; however, state-of-the-art techniques in CMR allow the assessment of cardiac tissue characterization and hemodynamics in the pulmonary arteries. Comprehensive knowledge of the role of imaging in CTEPH enables appropriate use of imaging modalities and accurate image interpretation, resulting in early diagnosis, determination of treatment strategies, and appropriate evaluation of treatment efficacy. This review summarizes the current roles of imaging in the clinical practice for CTEPH, demonstrating the characteristic findings observed in each modality.

Cardiovascular computed tomography (CT) angiography has become an established alternative to invasive catheter angiography. However, imaging artifacts due to partial volume effects with current systems hinder accurate evaluation of calcified or stented segments. Increased spatial resolution may allow to overcome these barriers to precise delineation of vascular disease. Recent developments in CT hardware and reconstruction have enabled CT angiography with ultra-high spatial resolution (UHRCT). In this review we aim to describe the methods to achieve greater spatial resolution in CT that are either in clinical or preclinical stage. In addition, we provide an overview of the available clinical evidence including diagnostic accuracy studies supporting improved vascular assessment with this technology. The benefits that can be gleaned from the initial experiences with UHRCT are promising. Using UHRCT, more patients may receive non-invasive characterization of coronary atherosclerosis by overcoming the limitations of current CT spatial resolution in visualizing and quantifying calcified, stented or small diameter segments. UHRCT may potentially impact existing management pathways as well as contribute to better understanding of the underlying pathophysiology of both macro- and microvascular disease.

Coronary CT angiography (CCTA) has emerged as a powerful noninvasive tool for characterizing the presence, extent, and severity of coronary artery disease (CAD) in patients with stable angina. Recent technological advancements in CT scanner hardware and software have augmented the rich information that can be derived from a single CCTA study. Beyond merely identifying the presence of CAD and assessing stenosis severity, CCTA now allows for the identification and characterization of plaques, lesion length, and fluoroscopic angle optimization, as well as enables the assessment of the physiologic extent of stenosis through CT-derived fractional flow reserve, and may even allow for the prediction of the response to revascularization. These and other features make CCTA capable of not only guiding invasive coronary angiography referral, but also give it the unique ability to help plan coronary intervention. This review summarizes current and future applications of CCTA in procedural planning for percutaneous coronary intervention, provides rationale for wider integration of CCTA in the workflow of the interventional cardiologist, and details how CCTA may help improve patient care and clinical outcomes. Keywords: CT Angiography © RSNA, 2022.

Bicuspid aortic valve (BAV) patients with aortic stenosis (AS) are known to develop dilatation of the ascending aorta at a younger age, but the morphology of the aorta in these patients is yet to be investigated. Thus, in this study, we aim to evaluate the aortic morphology of BAV patients with severe AS using thin-slice electrocardiogram (ECG) -gated computed tomography (CT) and identify the possible contributing effect of age.In this retrospective study, 122 BAV and 154 tricuspid aortic valve (TAV) patients who received aortic valve replacement for severe AS were assessed by thin-slice ECG-gated CT and three-dimensional reconstruction. The morphology of the ascending aorta was also evaluated among BAV patients aged < 70 (n = 72) and ≥ 70 (n = 50) years old. As per our findings, BAV patients with severe AS had significantly greater diameter (P < 0.01), elongation (P < 0.01), and tortuosity (P = 0.03) of the ascending aorta; minimum aortic arch angle (P < 0.01); and significantly lower calcified plaque (P < 0.01) compared with those of TAV patients even after adjusting for background. Multiple regression analysis showed that standardized partial regression coefficients (β) of dilatation (0.5) and elongation (0.35) were higher among other measurements of aortic morphology for BAV patients. BAV patients with severe AS aged ≥ 70 years had significantly greater diameter (42.0 [37.2-46.1] mm versus 40.4 [35.2-44.2] mm, P = 0.049) and elongation (133.8 [123.5-147.3] mm versus 127.0 [111.0-140.0] mm, P = 0.01) of the ascending aorta than those aged < 70 years.BAV patients with severe AS were determined to have greater dilatation and elongation of the ascending aorta. Moreover, BAV patients older than 70 years had greater diameter and elongation of the ascending aorta.

Ischemic heart disease is the most common cause of mortality worldwide. The pathophysiology of myocardial infarction relates to temporal changes of atherosclerotic plaque culminating in plaque rupture, erosion or hemorrhage and the subsequent thrombotic response. Coronary computed tomographic angiography (CCTA) provides the ability to visualize and quantify plaque, and plaque progression can be measured on a per-patient basis by comparing findings of serial CCTA. The Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography IMaging (PARADIGM) registry was established with the objective of identifying patterns of plaque progression in a large population. The registry comprises over 2000 patients with multiple CCTA scans performed at least two years apart. Unlike previous CCTA registries, a semi-automated plaque quantification technique permitting detailed analysis of plaque progression was performed on all patients with interpretable studies. Since the registry was established, 19 peer-reviewed publications were identified, and all are reviewed and summarized in this article.

BACKGROUND: The role of change in fractional flow reserve derived from CT (FFRCT) across coronary stenoses (ΔFFRCT) in guiding downstream testing in patients with stable coronary artery disease (CAD) is unknown. OBJECTIVES: To investigate the incremental value of ΔFFRCT in predicting early revascularization and improving efficiency of catheter laboratory utilization. MATERIALS: Patients with CAD on coronary CT angiography (CCTA) were enrolled in an international multicenter registry. Stenosis severity was assessed as per CAD-Reporting and Data System (CAD-RADS), and lesion-specific FFRCT was measured 2 ​cm distal to stenosis. ΔFFRCT was manually measured as the difference of FFRCT across visible stenosis. RESULTS: Of 4730 patients (66 ​± ​10 years; 34% female), 42.7% underwent ICA and 24.7% underwent early revascularization. ΔFFRCT remained an independent predictor for early revascularization (odds ratio per 0.05 increase [95% confidence interval], 1.31 [1.26-1.35]; p ​< ​0.001) after adjusting for risk factors, stenosis features, and lesion-specific FFRCT. Among the 3 models (model 1: risk factors ​+ ​stenosis type and location ​+ ​CAD-RADS; model 2: model 1 ​+ ​FFRCT; model 3: model 2 ​+ ​ΔFFRCT), model 3 improved discrimination compared to model 2 (area under the curve, 0.87 [0.86-0.88] vs 0.85 [0.84-0.86]; p ​< ​0.001), with the greatest incremental value for FFRCT 0.71-0.80. ΔFFRCT of 0.13 was the optimal cut-off as determined by the Youden index. In patients with CAD-RADS ≥3 and lesion-specific FFRCT ≤0.8, a diagnostic strategy incorporating ΔFFRCT >0.13, would potentially reduce ICA by 32.2% (1638-1110, p ​< ​0.001) and improve the revascularization to ICA ratio from 65.2% to 73.1%. CONCLUSIONS: ΔFFRCT improves the discrimination of patients who underwent early revascularization compared to a standard diagnostic strategy of CCTA with FFRCT, particularly for those with FFRCT 0.71-0.80. ΔFFRCT has the potential to aid decision-making for ICA referral and improve efficiency of catheter laboratory utilization.

OBJECTIVES: This study sought to investigate the impact of low tube voltage scanning heterogeneity of coronary luminal attenuation on plaque quantification and characterization with coronary computed tomography angiography (CCTA). BACKGROUND: The impact of low tube voltage and coronary luminal attenuation on quantitative coronary plaque remains uncertain. METHODS: A total of 1,236 consecutive patients (age: 60 ± 9 years; 41% female) who underwent serial CCTA at an interval of ≥2 years were included from an international registry. Patients with prior revascularization or nonanalyzable coronary CTAs were excluded. Total coronary plaque volume was assessed and subclassified based on specific Hounsfield unit (HU) threshold: necrotic core, fibrofatty plaque, and fibrous plaque and dense calcium. Luminal attenuation was measured in the aorta. RESULTS: With increasing luminal HU (<350, 350-500, and >500 HU), percent calcified plaque was increased (16%, 27%, and 40% in the median; P < 0.001), and fibrofatty plaque (26%, 13%, and 4%; P < 0.001) and necrotic core (1.6%, 0.3%, and 0.0%; P < 0.001) were decreased. Higher tube voltage scanning (80, 100, and 120 kV) resulted in decreasing luminal attenuation (689 ± 135, 497 ± 89, and 391 ± 73 HU; P < 0.001) and calcified plaque volume (59%, 34%, and 23%; P < 0.001) and increased fibrofatty plaque (3%, 9%, and 18%; P < 0.001) and necrotic core (0.2%, 0.1%, and 0.6%; P < 0.001). Mediation analysis showed that the impact of 100 kV on plaque composition, compared with 120 kV, was primarily caused by an indirect effect through blood pool attenuation. Tube voltage scanning of 80 kV maintained a direct effect on fibrofatty plaque and necrotic core in addition to an indirect effect through the luminal attenuation. CONCLUSIONS: Low tube voltage usage affected plaque morphology, mainly through an increase in luminal HU with a resultant increase in calcified plaque and a reduction in fibrofatty and necrotic core. These findings should be considered as CCTA-based plaque measures are being used to guide medical management and, in particular, when being used as a measure of treatment response. (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging [PARADIGM]; NCT02803411).

OBJECTIVE: To compare left ventricular (LV) and right ventricular (RV) volume, function, and image quality of a respiratory-triggered two-dimensional (2D)-cine k-adaptive-t-autocalibrating reconstruction for Cartesian sampling (2D kat-ARC) with those of the standard reference, namely, breath-hold 2D balanced steady-state free precession (2D SSFP), in patients with repaired tetralogy of Fallot (TOF). METHODS: 30 patients (14 males, mean age 32.2 ± 13.9 years) underwent cardiac magnetic resonance, and 2D kat-ARC and 2D SSFP images were acquired on short-axis view. Biventricular end-diastolic volume (EDV) and end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and LV mass (LVM) were analysed. RESULTS: The 2D kat-ARC had significantly shorter scan time (35.2 ± 9.1 s vs 80.4 ± 16.7 s; p < 0.0001). Despite an analysis of image quality showed significant impairment using 2D kat-ARC compared to 2D SSFP cine (p < 0.0001), the two sequences demonstrated no significant difference in terms of biventricular EDV, LVESV, LVSV, LVEF, and LVM. However, the RVESV was overestimated for 2D kat-ARC compared with that for 2D SSFP (73.8 ± 43.2 ml vs 70.3 ± 44.5 ml, p = 0.0002) and the RVSV and RVEF were underestimated (RVSV = 46.2±20.5 ml vs 49.4 ± 20.4 ml, p = 0.0024; RVEF = 40.2±12.7% vs. 43.5±14.0%, p = 0.0002). CONCLUSION: Respiratory-triggered 2D kat-ARC cine is a reliable technique that could be used in the evaluation of LV volumes and function. ADVANCES IN KNOWLEDGE: 2D cine kat-ARC is a reliable technique for the assessment LV volume and function in patients with repaired TOF.

Purpose: To develop and validate a CT diagnostic algorithm for bicuspid aortic valve (BAV) classification. Materials and Methods: This retrospective study included 212 consecutive patients with severe aortic stenosis who underwent CT followed by aortic valve replacement (mean age, 71 years [range, 27-93 years]; 125 women; 37% with a BAV) from 2012 to 2017. BAV diagnosis and BAV category were determined by using the CT diagnostic algorithm developed and were compared with those attained through surgical diagnosis. Reproducibility and agreement were assessed using the Cohen kappa (κ) coefficient. The value of adding CT to age, aortic diameter index, and transthoracic echocardiography (TTE) was evaluated by using the area under the receiver operating characteristic curve (AUC), net reclassification improvement (NRI), and decision-curve analysis. Results: Intra- and interobserver reproducibility were good or excellent for all CT diagnoses (κ ≥ 0.6 for all). Agreement between CT and surgical diagnoses was excellent (κ = 0.90) for BAV detection and good (κ = 0.69) for BAV categorization. Sixteen percent (five of 31) of patients with functional BAV diagnosed by using CT received a diagnosis of congenital BAV at surgery. The addition of CT to age, aortic diameter, and TTE showed a higher AUC (with CT, 0.97 [95% CI: 0.91, 0.99] vs without CT, 0.91 [95% CI: 0.85, 0.95]; P = .003) and NRI (1.79 [95% CI: 1.65, 1.92], P < .001) and a higher net benefit among all BAV probabilities. Conclusion: CT diagnosis was consistent with surgical diagnosis and had an additive value over traditional diagnostic methods; however, there was a risk of overlooking congenital BAV in patients with functional BAV diagnosed by using CT.Supplemental material is available for this article.© RSNA, 2021.

Objectives: This study compared cardiac function, morphology, and tissue characteristics between two common subtypes of primary aldosteronism (PA) using a 3T MR scanner. Design: A retrospective, single-center, observational study. Methods: We retrospectively reviewed 143 consecutive patients with PA, who underwent both adrenal venous sampling and cardiac magnetic resonance. We acquired cine, late gadolinium enhancement, and pre- and postcontrast myocardial T1-mapping images. Results: PA was diagnosed as unilateral aldosterone-producing adenoma (APA) in 70 patients and bilateral hyperaldosteronism (BHA) in 73. The APA group showed significantly higher plasma aldosterone concentration (PAC) and aldosterone to renin rate (ARR) than the BHA group. After controlling for age, sex, antihypertensive drugs, systolic and diastolic blood pressure, and disease duration, the parameters independently associated with APA were: left ventricular end-diastolic volume index (EDVI: adjusted odds ratio (aOR) = 1.06 (95% CI: 1.030-1.096), P < 0.01), end-systolic volume index (ESVI: 1.06 (1.017-1.113), P < 0.01), stroke index (SI: 1.07 (1.020-1.121), P < 0.01), cardiac index (CI: 1.001 (1.000-1.001), P < 0.01), and native T1 (1.01 (1.000-1.019), P = 0.038). Weak positive correlations were found between PAC and EDVI (R = 0.28, P < 0.01), ESVI (0.26, P < 0.01), and SI (0.18, P = 0.03); and between ARR and EDVI (0.25, P < 0.01), ESVI (0.24, P < 0.01), and native T1 (0.17, P = 0.047). Conclusions: APA is associated with greater LV volumetric parameters and higher native T1 values, suggesting a higher risk of volume overload and myocardial damage.

PURPOSE: The purpose of this prospective study was to evaluate radiation-induced myocardial damage after mediastinal radiation therapy (RT) using late gadolinium-enhancement (LGE) magnetic resonance imaging (MRI). METHODS AND MATERIALS: We enrolled 19 patients with esophageal cancer who were expected to have long-term survival by definitive treatment. They underwent delayed contrast-enhanced MRI (19 patients before treatment, 19 patients 6 months after treatment, and 12 patients 1.5 years after treatment). Dose distribution of the left ventricle was made using computed tomography, and the dose volume histogram of the left ventricle was calculated. Myocardial signal intensities in individual MRIs were normalized by the mean values in regions receiving low doses (<5 Gy). Changes in the normalized signal intensities after mediastinal radiation therapy were compared among regions where irradiation doses were 0 to 10 Gy, 10 to 20 Gy, 20 to 30 Gy, 30 to 40 Gy, 40 to 50 Gy, and 50 to 60 Gy, and we investigated whether intensity change was detected in a dose-dependent manner. RESULTS: The registered patients were treated with concurrent chemoradiotherapy with a median total dose of 60 Gy (50.4-66 Gy). Chemotherapy consisting of cisplatin and 5-fluorouracil was administered. In the population-based dose-response curve, dose-dependent intensity changes progressively increased in regions receiving more than 30 Gy. The averages of relative intensity change at 6 months and 1.5 years after treatment were 1.1% and -1.9% at 20 to 30 Gy and 37.5% and 17.5% at 40 to 50 Gy, respectively. LGE in regions receiving more than 30 Gy was detected in 68% (13/19) of the patients. CONCLUSIONS: A dose-dependent relationship for myocardial signal intensity change was found by using LGE MRI. It may be necessary to reduce the volume of the myocardium receiving more than 30 Gy.

BACKGROUND: Cardiac magnetic resonance (CMR) imaging has become the principal noninvasive imaging modality for the diagnosis of cardiac sarcoidosis (CS) patients. This study aimed to determine the diagnostic performance of CMR imaging for CS in new-onset complete heart block (CHB) patients implanted with magnetic resonance-conditional pacemaker (MRCP). METHODS: Fifty CHB patients implanted with MRCP were enrolled in this study. Clinical CS was diagnosed if there was a histological diagnosis of extra-cardiac sarcoidosis in patients with CHB based on the consensus statement; clinical CS was the reference standard. The diagnostic performance of CMR sequences, including cine magnetic resonance imaging (MRI), increased T2-weighted signal (T2WS), and late gadolinium enhancement (LGE), for clinical CS was investigated. We also compared the diagnostic performance of CMR sequences between the entire left ventricle (LV) and the basal septum, which involves the electrical pathway of atrioventricular conduction. RESULTS: In total, 8 of the 50 patients with CHB were confirmed to have extra-cardiac sarcoidosis and were diagnosed with clinical CS. The accuracy, sensitivity, and specificity of LGE in the basal septum and entire LV were 94%, 100%, and 93% and 80% (p = 0.023), 100% (p = 1.00), and 76% (p = 0.023), respectively. The accuracy, sensitivity, and specificity of increased T2WS and cine MRI in the basal septum were 94%, 75%, and 98% and 90%, 38%, and 100%, respectively. There was no statistical difference between the entire LV and the basal septum for the diagnostic performance of increased T2WS and cine MRI. CONCLUSIONS: CMR can be a diagnostic tool for evaluating clinical CS in patients with CHB implanted with MRCP. LGE in the basal septum might provide the overall best diagnostic performance for clinical CS with CHB.

BACKGROUND: An optimal system for interpreting fractional flow reserve (FFR) values derived from CT (FFRCT) is lacking. We sought to evaluate performance of three FFRCT measurements in detecting ischemia by comparing them with invasive FFR. METHODS: For 73 vessels in 50 patients who underwent coronary CT angiography (CCTA) and FFRCT analysis followed by invasive FFR, the greatest diameter stenosis on CCTA, FFRCT difference between distal and proximal to the stenosis (ΔFFRCT), FFRCT 2 cm distal to the stenosis (lesion-specific FFRCT), and the lowest FFRCT in distal vessel tip were calculated. Significant obstruction (≥50% diameter stenosis) and ischemia (lesion-specific FFRCT ≤0.80, the lowest FFRCT ≤0.80, or ΔFFRCT ≥0.12 based on the greatest Youden index) were compared with invasive FFR (≤0.80). RESULTS: Forty (55%) vessels demonstrated ischemia during invasive FFR. On multivariable generalized estimating equations, ΔFFRCT (odds ratio [OR] 10.2, p < 0.01) remained a predictor of ischemia over CCTA (OR 2.9), lesion-specific FFRCT (OR 3.1), and the lowest FFRCT (OR 0.9) (p > 0.05 for all). Area under the curve (AUC) of ΔFFRCT (0.86) was higher than CCTA (0.66), lesion-specific FFRCT (0.71), and the lowest FFRCT (0.65) (p < 0.01 for all). Addition of each FFRCT measure to CCTA showed improvement of AUC and significant net reclassification improvement (NRI): ΔFFRCT (AUC 0.84, NRI 1.24); lesion-specific FFRCT (AUC 0.77, NRI 0.83); and the lowest FFRCT (AUC 0.76, NRI 0.59) (p < 0.01 for all). CONCLUSIONS: Compared with diameter stenosis, ΔFFRCT, lesion-specific FFRCT, and the lowest FFRCT improved ischemia discrimination and reclassification, with ΔFFRCT being superior in identifying and discriminating ischemia.

Purpose To assess changes in left ventricular function and tissue composition by using MRI after chemotherapy-radiation therapy in participants with esophageal cancer. Materials and Methods Between January 2013 and April 2015, this prospective study enrolled 24 participants (42% women; mean age, 63 years; range, 49-73 years) scheduled for chemotherapy-radiation therapy. 3.0-T MRI examinations were performed before, at 0.5 year, and at 1.5 years after chemotherapy-radiation therapy. Myocardial native T1, postcontrast T1, and extracellular volume were measured in basal septum (as irradiated areas) and apical lateral wall (as nonirradiated areas). Left ventricular function, prevalence of late gadolinium enhancement, and T1 and extracellular volume values were compared over the follow-up period by using Friedman or Cochran Q tests, followed by Dunn test. Results In 14 participants who were followed up for 1.5 years, native T1 and extracellular volume in the septum were elevated at 0.5 year compared with baseline (1183 msec ± 46 [standard deviation] vs 1257 msec ± 35; 26% ± 3 vs 32% ± 3; adjusted P < .01 for both), but not in the lateral wall. Left ventricular stroke volume index and late gadolinium enhancement changed at 1.5 years compared with baseline (41 mL/m2 ± 11 vs 36 mL/m2 ± 9; P = .046; 7% [one of 14] vs 78% [11 of 14]; P < .01). Other measures of left ventricular function did not change during the follow-up period (P > .10 for all). Conclusion Native T1 and extracellular volume could detect early changes in myocardium at 0.5 year after chemotherapy-radiation therapy, whereas left ventricular stroke volume index and late gadolinium enhancement showed abnormality at 1.5 years. © RSNA, 2018 Online supplemental material is available for this article.

OBJECTIVES: Preoperative identification of the artery of Adamkiewicz can help prevent postoperative spinal cord injury in patients undergoing thoracic and thoraco-abdominal aortic aneurysm repair. Although several studies have shown the feasibility of evaluating the artery of Adamkiewicz using multidetector row computed tomography (MDCT), no detailed investigations regarding the collateral circulation to the artery of Adamkiewicz have been performed. The purpose of this study was to investigate the collateral circulation to the artery of Adamkiewicz using MDCT in patients with thoracic and thoraco-abdominal aortic aneurysms. METHODS: Our institutional review board approved this study. Sixty-four patients with descending thoracic and thoraco-abdominal aortic aneurysms associated with the occlusion of the segmental artery from which the artery of Adamkiewicz originated were scanned using 64- or 320-detector row computed tomography. Two independent observers evaluated the MDCT images based on the degree of visualization of the artery of Adamkiewicz and its collateral circulation using a 4-point scale. RESULTS: The average visualization score was 2.8 ± 0.6. In 53 of the 64 (83%) patients, image quality was judged to be diagnostic. MDCT demonstrated 75 collateral pathways to the artery of Adamkiewicz in these 53 patients. Sixty-four of the 75 (85%) pathways were collaterals around the spinal column, and the remaining 11 (15%) pathways were collateral arteries in the thoracic wall. CONCLUSIONS: MDCT revealed the collateral pathways to the artery of Adamkiewicz around the spinal column and in the thoracic wall in 83% of our patients with thoracic and thoraco-abdominal aortic aneurysms.