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Background Recent evidence suggests that left atrial (LA) dysfunction may be mechanistically contributing to cerebrovascular events in patients with atrial fibrillation (AF). We investigated the association between regional LA function and a prior history of stroke during sinus rhythm in patients referred for catheter ablation of AF. Methods and Results A total of 169 patients (59 ± 10 years, 74% male, 29% persistent AF) with a history of AF in sinus rhythm at the time of pre‐ablation cardiac magnetic resonance (CMR) were analyzed. The LA volume, emptying fraction, strain (S), and strain rate (SR) were assessed by tissue‐tracking cardiac magnetic resonance. The patients with a history of stroke or transient ischemic attack (n=18) had greater LA volumes (V max and V min ; P =0.02 and P P max and S preA ; P P =0.01, respectively), and lower absolute values of LA SR during left ventricular (LV) systole and early diastole (SR s and SR e ; P =0.005 and 0.03, respectively) than those without stroke/transient ischemic attack (n=151). Multivariable analysis demonstrated that the LA reservoir function, including total emptying fraction, S max , and SR s , was associated with stroke/transient ischemic attack (odds ratio 0.94, 0.91, and 0.17; P =0.03, 0.02, and 0.04, respectively) after adjusting for the CHA 2 DS 2 ‐VASc score and LA V min . Conclusions Depressed LA reservoir function assessed by tissue‐tracking cardiac magnetic resonance is significantly associated with a prior history of stroke/transient ischemic attack in patients with AF. Our findings suggest that assessment of LA reservoir function can improve the risk stratification of cerebrovascular events in AF patients.

We describe a case with three focal atrial tachycardias (ATs) and focal atrial fibrillation (AF) originating from the interatrial septum (IAS) near the atrioventricular node (AVN). Contrast-enhanced computed tomography demonstrated the association of fat deposition within the anterior IAS near the AVN with successful ablation sites of these ATs and AF. This is the first report that the intramural fat deposition in the IAS could be associated with the formation of AT and AF re-entry circuits originating near the AVN.

Aims To investigate whether hypertrophic cardiomyopathy (HCM) patients with late gadolinium enhancement (LGE) confined to the right ventricular insertion points (RVIP) differ phenotypically from patients without LGE or intramural LGE in the left ventricle (LV). Methods and results Sixty-two HCM patients underwent cardiac magnetic resonance for quantification of LGE (% LV mass) and were classified as group (i) no-LGE ( n = 18), group (ii) LGE-RVIP ( n = 19), and group (iii) intramural LGE ( n = 25). All patients also underwent vasodilator N-13 ammonia PET to quantify myocardial blood flow (MBF) and myocardial flow reserve (MFR), and echocardiography to measure longitudinal LV strain. LGE extent (17 ± 11% vs. 4 ± 4% vs. 0%; P < 0.001) and LV thickness (21.7 ± 3.4 vs. 18.8 ± 3.9 vs. 16.3 ± 2.8 mm; P < 0.001) were significantly greater in group 3, intermediate in group 2, and lower in group 1. In contrast, stress MBF (1.62 ± 0.44 vs. 1.90 ± 0.37 vs. 2.22 ± 0.48 mL/min/g; P < 0.001); MFR (1.92 ± 0.47 vs. 2.15 ± 0.52 vs. 2.71 ± 0.52; P < 0.001), and longitudinal LV strain (−11.4 ± 3.8 vs. −12.6 ± 3.2 vs. −14.4 ± 4.1%; P = 0.04) were lower in group 3, intermediate in group 2, and higher in group 1. Conclusions From an imaging viewpoint, patients with LGE confined to only the RVIP appear to represent an intermediate-stage phenotype between patients with no LGE and intramural LGE in the LV.

Background— Atrial fibrillation (AF) is associated with left atrial (LA) structural and functional changes. Cardiac magnetic resonance late gadolinium enhancement (LGE) and feature-tracking are capable of noninvasive quantification of LA fibrosis and myocardial motion, respectively. We sought to examine the association of phasic LA function with LA enhancement in patients with AF. Methods and Results— LA structure and function was measured in 90 patients with AF (age 61±10 years; 76% men) referred for ablation and 14 healthy volunteers. Peak global longitudinal LA strain, LA systolic strain rate, and early and late diastolic strain rates were measured using cine–cardiac magnetic resonance images acquired during sinus rhythm. The degree of LGE was quantified. Compared with patients with paroxysmal AF (60% of cohort), those with persistent AF had larger maximum LA volume index (56±17 versus 49±13 mL/m 2 ; P =0.036), and increased LGE (27.1±11.7% versus 36.8±14.8%; P P P P Conclusions— Increased LA enhancement is associated with decreased LA reservoir, conduit, and booster pump functions. Phasic measurement of LA function using feature-tracking cardiac magnetic resonance may add important information about the physiological importance of LA fibrosis.

Background Previous studies have shown that contrast-enhanced multidetector computed tomography (CE-MDCT) could identify ventricular fibrosis after myocardial infarction. However, whether CE-MDCT can characterize atrial low-voltage regions remains unknown. Objective The purpose of this study was to examine the association of CE-MDCT image attenuation with left atrial (LA) low bipolar voltage regions in patients undergoing repeat ablation for atrial fibrillation recurrence. Methods We enrolled 20 patients undergoing repeat ablation for atrial fibrillation recurrence. All patients underwent preprocedural 3-dimensional CE-MDCT of the LA, followed by voltage mapping (>100 points) of the LA during the ablation procedure. Epicardial and endocardial contours were manually drawn around LA myocardium on multiplanar CE-MDCT axial images. Segmented 3-dimensional images of the LA myocardium were reconstructed. Electroanatomic map points were retrospectively registered to the corresponding CE-MDCT images. Results A total of 2028 electroanatomic map points obtained in sinus rhythm from the LA endocardium were registered to the segmented LA wall CE-MDCT images. In a linear mixed model, each unit increase in the local image attenuation ratio was associated with 25.2% increase in log bipolar voltage (P = .046) after adjusting for age, sex, body mass index, and LA volume, as well as clustering of data by patient and LA regions. Conclusion We demonstrate that the image attenuation ratio derived from CE-MDCT is associated with LA bipolar voltage. The potential ability to image fibrosis via CE-MDCT may provide a useful alternative in patients with contraindications to magnetic resonance imaging.

The application of dual energy techniques to peripheral angiography in the upper and lower limbs has the potential to improve clinical workflow and study accuracy. Dual-energy techniques optimize postprocessing of three-dimensional data sets with more accurate and efficient bone removal compared to traditional techniques. Recent evidence suggests that monoenergetic reconstructions have the potential for improved vessel contrast over standard polyenergetic, single-energy techniques which may allow studies to be done with reduced contrast volumes. In this chapter, we will review current state of dual-energy imaging as it relates to peripheral angiography, highlighting technical aspects that pertain to the lower extremities, standardized protocols, the current state of evidence in the field, as well as potential advantages and disadvantages of the technique. Finally, we will provide illustrated descriptions of important clinical applications.

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a rare inherited cardiomyopathy characterized by fibrofatty replacement of the right ventricular myocardium and risk of sudden death from ventricular tachyarrhythmias. Cardiac magnetic resonance (MR) imaging plays an important role in the diagnostic evaluation of patients and family members suspected of having ARVC/D. This article discusses the epidemiology and pathophysiology of ARVC/D, reviews typical MR imaging findings and diagnostic criteria, and summarizes potential pitfalls in the MR imaging evaluation of patients suspected of having ARVC/D.

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by regional wall motion abnormalities of the right ventricle (RV) that have not previously been quantified, resulting in challenges / errors in diagnosis of the disease. RV strain is poorly assessed with tagged cardiac magnetic resonance (CMR) due to the thin RV wall. We applied novel feature tracking analysis to assess RV strain in patients with ARVC. Methods: 106 subjects (30 controls, 37 preclinical ARVC [mutation+], and 39 overt ARVC [mutation+, Task Force+] patients) underwent 4 chamber and axial cine imaging using SSFP sequences. The RV was divided into subtricuspid (ST), anterior wall (AW), and apical (Ap) regions. Each region was analyzed to determine peak longitudinal strain and strain-rate using Multimodality Tissue Tracking (MTT) software (MTT Version 6.0.4725, Toshiba Medical Systems Corporation, Tokyo, Japan). Results: Average age was 33.6 ± 16.1 years (48.2% women); there were no differences between groups. In the 4 chamber view, mean global and segmental strain and strain rates decreased in magnitude from control (-37.7% ± 11.2) to preclinical (-32.2% ± 11.5) to overt ARVC (mean -22.2% ± 11.9). Differences between groups most pronounced in the subtricuspid segment, and reached statistical significance between overt ARVC and both control and preclinical ARVC (p < 0.01). A similar trend was observed in longitudinal strain measured in the axial view, but these trends were inconsistent; statistical significance was met globally, but most individual segments did not reach statistical significance. Conclusions: Longitudinal RV strain as measured by CMR feature tracking in ARVC appears able to quantify wall motion abnormalities in overt ARVC, as well as define subtle abnormalities in patients with preclinical ARVC.

Introduction: Atrial fibrillation (AF) is associated with left atrial (LA) electrical, structural, and contractile remodeling. Cardiac magnetic resonance (CMR), late gadolinium enhancement (LGE) and feature tracking are capable of noninvasive quantification of LA fibrosis and myocardial motion, respectively. Hypothesis: Increased LA fibrosis measured with LGE is associated with worsening of the phasic LA function measured with feature tracking CMR. Methods: The cohort included 90 patients (age 61 ± 10 years, 76% male) with symptomatic drug-resistant AF referred for ablation. Peak global longitudinal LA strain (PLAS), LA systolic strain rate (SR-s), and early (SR-ed) and late diastolic (SR-ld) strain rates were measured using cine-CMR images acquired during sinus rhythm. The degree of LGE was quantified using normalized image intensity. Results: Compared to patients with paroxysmal AF (60% of cohort), those with persistent AF had larger maximum LA volume index (LAVImax, 56 ± 17ml/m2 versus 49 ± 13ml/m2 p=0.036), and increased LGE (27.1± 11.7% versus 36.8 ± 14.8% p Conclusions: Increased LA fibrosis is associated with decreased LA reservoir, conduit, and booster pump functions. Phasic measurement of LA function using feature-tracking CMR is feasible and may add important information regarding the physiological importance of LA fibrosis.

Postablation atrial fibrillation recurrence is positively associated with the extent of preexisting left atrial (LA) late gadolinium enhancement (LGE) on magnetic resonance imaging (MRI), but negatively associated with the extent of postablation LGE regardless of proximity to the pulmonary vein antra. The characteristics of pre- vs postablation LA LGE may provide insight into this seeming paradox and inform future strategies for ablation.The purpose of this study was to define the characteristics of preexisting vs ablation-induced LA LGE.LGE-MRI was prospectively performed before and ≥3 months after initial ablation in 20 patients. The intracardiac locations of ablation points were coregistered with the corresponding sites on axial planes of postablation LGE-MRI. The image intensity ratio (IIR), defined as the LA myocardial MRI signal intensity divided by the mean LA blood pool intensity, and LA myocardial wall thickness were calculated on pre- and postablation images.Imaging data from 409 pairs of pre- and postablation axial LGE-MRI planes and 6961 pairs of pre- and postablation image sectors were analyzed. Ablation-induced LGE revealed a higher IIR, suggesting greater contrast uptake and denser fibrosis, than did preexisting LGE (1.25 ± 0.25 vs 1.14 ± 0.15; P.001). In addition, ablation-induced LGE regions had thinner LA myocardium (2.10 ± 0.67 mm vs 2.37 ± 0.74 mm; P.001).Regions with ablation-induced LGE exhibit increased contrast uptake, likely signifying higher scar density, and thinner myocardium as compared with regions with preexisting LGE. Future studies examining the association of postablation LGE intensity and nonuniformity with ablation success are warranted and may inform strategies to optimize ablation outcome.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a familial cardiomyopathy characterized by fibrofatty replacement of the myocardium, ventricular tachycardia, and ventricular dysfunction that affects primarily the right ventricle (RV). This disease is not common but can be seen more frequently in young adults, and clinical manifestations range from no symptoms to lethal arrhythmia and sudden death. The diagnosis of ARVC is challenging and is based on the recently revised international task force criteria. Given the strengths of cardiac magnetic resonance (MR) imaging for depicting the RV, this modality plays an important role in the diagnosis of ARVC. Functional and structural abnormalities of the RV depicted with cardiac MR imaging constitute major and minor criteria in the revised task force criteria. Since the ARVC program was established at our center in 1998, there has been an increased awareness of a number of normal variants that are commonly misinterpreted as showing evidence for ARVC. On the basis of our clinical experience, the overdiagnosis of ARVC appears to reflect two fundamental problems: (a) a lack of awareness of diagnostic criteria that identify major and minor variables to be used for the diagnosis of ARVC, and (b) a lack of familiarity with the normal variants and mimics that may be misinterpreted as showing evidence of ARVC. The purpose of this article is to review the typical patterns of ventricular involvement in ARVC at cardiac MR imaging and to compare those with the patterns of normal variants and other diseases that can mimic ARVC. Online supplemental material is available for this article.

Myocardial fat deposition (FAT-DEP) has been frequently observed in regions of chronic myocardial infarction in patients with ischemic cardiomyopathy. The role of FAT-DEP within scar-related ventricular tachycardia (VT) circuits has not been investigated.This pilot study aimed to assess the impact of myocardial FAT-DEP on local electrograms and VT circuits in patients with ischemic cardiomyopathy.Contrast-enhanced computed tomography was performed in 22 patients with ischemic VT. Electroanatomic map points were registered to the corresponding contrast-enhanced computed tomography images. Myocardial FAT-DEP was identified and characterized using a postprocessing image overlay that highlighted areas below 0 Hounsfield units (HU). The mean attenuation of local myocardial regions corresponding to sampled electrograms was measured on short-axis images. The associations of mean attenuation with bipolar and unipolar amplitudes, left ventricular wall thickness, and VT circuit sites were investigated.Of 1801 electroanatomic map points, 519 (28.8%) were located in regions with FAT-DEP. Significant differences were observed in mean intensity (23.2 ± 35.6 HU vs 81.7 ± 21.9 HU; P.001), bipolar (0.75 ± 0.83 mV vs 2.9 ± 2.4 mV; P.001) and unipolar (3.1 ± 1.7 mV vs 7.4 ± 4.3 mV; P.001) amplitudes, and left ventricular wall thickness (5.2 ± 1.7 mm vs 8.2 ± 2.5 mm; P.001) between regions with and without FAT-DEP. Lower HU was strongly associated with lower bipolar and unipolar amplitudes (P.0001, respectively). Importantly, FAT-DEP was associated with critical VT circuit sites with fractionated or isolated potentials.FAT-DEP was associated with electrogram characteristics and VT circuit sites. Further work will be needed to determine whether FAT-DEP plays a causal role in the generation of ischemic scar-related VT circuits.

I greatly enjoyed reading the comprehensive iReviews article from Baliga et al. [(1)][1]. The authors have provided a detailed summary of the topic with compelling illustrations and multidetector computed tomography images. However, I feel it is necessary to point out an error in the description

OBJECTIVES For dual-source cardiac computed tomography (CT) scans without heart rate (HR) control, the influence of body habitus on quality is uncertain. We evaluated study quality across a range of HRs and body size. METHODS One hundred sixty subjects were randomly selected for 4 HR groups (

Myocardial calcifications are not uncommonly encountered by the cardiac imager and may have a range of imaging appearances, from focal calcific deposits to diffuse myocardial involvement. A number of pathological processes can both cause and result from myocardial calcification; therefore, accurate identification and characterization are important. This pictorial essay will review the mechanisms, etiologies, imaging features, and differential diagnoses of myocardial calcification with imaging examples.

Evaluation of acute aortic dissection by computed tomography angiography provides detailed characterization of this disease beyond the Stanford classification. Recent publications based on large patient registries and other sources have identified morphological characteristics that impact patient prognosis, and advanced understanding of both the incidence and demographics of this disease. This article reviews the recent literature and discusses the importance of imaging findings, such as aortic/false lumen diameter, signs of organ malperfusion, false lumen thrombosis, and characterization of intimal tears. The associated entity acute intramural hematoma is discussed, as well as imaging features that predict adverse outcomes. Familiarity with these imaging characteristics maximizes the utility of radiographic evaluation in this disease.

Myocardial fibrosis is a common endpoint in a variety of cardiac diseases and a major independent predictor of adverse cardiac outcomes. Short of histopathologic analysis, which is limited by sampling bias, most diagnostic modalities are limited in their depiction of myocardial fibrosis. Cardiac magnetic resonance (MR) imaging has the advantage of providing detailed soft-tissue characterization, and a variety of novel quantification methods have further improved its usefulness. Contrast material-enhanced cardiac MR imaging depends on differences in signal intensity between regions of scarring and adjacent normal myocardium. Diffuse myocardial fibrosis lacks these differences in signal intensity. Measurement of myocardial T1 times (T1 mapping) with gadolinium-enhanced inversion recovery-prepared sequences may depict diffuse myocardial fibrosis and has good correlation with ex vivo fibrosis content. T1 mapping calculates myocardial T1 relaxation times with image-based signal intensities and may be performed with standard cardiac MR imagers and radiologic workstations. Myocardium with diffuse fibrosis has greater retention of contrast material, resulting in T1 times that are shorter than those in normal myocardium. Early studies have suggested that diffuse myocardial fibrosis may be distinguished from normal myocardium with T1 mapping. Large multicenter studies are needed to define the role of T1 mapping in developing prognoses and therapeutic assessments. However, given its strengths as a noninvasive method for direct quantification of myocardial fibrosis, T1 mapping may eventually play an important role in the management of cardiac disease.

Background— Although age and sex distributions of calcified coronary plaque have been well described in the general population, noncalcified plaque (NCP) distributions remain unknown. This is important because NCP is a putative precursor for clinical coronary artery disease and could serve as a sentinel for aggressive primary prevention, especially in high-risk populations. We examined the distributions of NCP and calcified coronary plaque in healthy 30- to 74-year-old individuals from families with early onset coronary artery disease. Methods and Results— Participants in the GeneSTAR family study (N=805), mean age 51.1±10.8 years, 56% women, were screened for coronary artery disease risk factors and coronary plaque using dual-source computed tomographic angiography. Plaque volumes (mm 3 ) were quantified using a validated automated method. The prevalence of coronary plaque was 57.8% in men and 35.8% in women ( P P P P 70% and >80%, respectively). Higher Framingham risk was associated with the number of affected vessels ( P Conclusions— The majority of coronary plaque was noncalcified, particularly in younger individuals. These findings support the importance of assessing family history and suggest that early primary prevention interventions may be warranted at younger ages in families with early onset coronary artery disease.

Circulating leptin levels are elevated during the later stages of pregnancy in mammals, suggesting that maternal leptin may play a role in maintenance of pregnancy and/or preparation for parturition and lactation. The regulation and source of circulating leptin during pregnancy remains undetermined, but leptin mRNA levels increase in adipose tissue during this time in some species. Considerable controversy exists whether placenta is also a leptin-secreting tissue during pregnancy. Here, we directly demonstrate that leptin secretion rates from mouse adipose tissue in vitro are decreased during early pregnancy and up-regulated during late pregnancy and lactation. Changes in leptin secretion rates in vitro paralleled those of circulating leptin in vivo during gestation. Subcutaneous implants of estradiol or corticosterone into lactating mice for 48 h stimulated adipose leptin secretion rates in vitro to the level of that in pregnant mice. However, corticosterone, but not estradiol, increased leptin secretion when added to isolated adipose tissue in vitro. Placentae obtained at two stages of pregnancy did not secrete leptin in vitro, either when acutely isolated or when dissociated into cells for long-term cultures. Placental tissue (or cells) secreted progesterone, however, demonstrating placental viability. We conclude that hyperleptinemia during late pregnancy in mice primarily results from corticosterone-dependent up-regulation of leptin secretion from adipose tissue, and that the placenta does not contribute to leptin secretion. The initial decrease in leptin secretory rates from adipose tissue during early pregnancy may facilitate energy storage for the subsequent, increased metabolic demands of later pregnancy and lactation.

BackgroundIncomplete penetrance and variable expressivity of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) complicate family screening.ObjectivesThe objective of the present study was to determine the optimal approach to longitudinal follow-up regarding: 1) screening interval; and 2) testing strategy in at-risk relatives of ARVD/C patients.MethodsWe included 117 relatives (45% male, age 33.3 ± 16.3 years) from 64 families who were at risk of developing ARVD/C by virtue of their familial predisposition (72% mutation carriers [92% plakophilin-2]; 28% first-degree relatives of a mutation-negative proband). Subjects were evaluated by electrocardiography (ECG), Holter monitoring, signal-averaged ECG, and cardiac magnetic resonance (CMR). Disease progression was defined as the development of a new criterion by the 2010 Task Force Criteria (not the “Hamid criteria”) at last follow-up that was absent at enrollment.ResultsAt first evaluation, 43 subjects (37%) fulfilled an ARVD/C diagnosis according to the 2010 Task Force Criteria. Among the remaining 74 subjects (63%), 11 of 37 (30%) with complete re-evaluation experienced disease progression during 4.1 ± 2.3 years of follow-up. Electrical progression (n = 10 [27%], including by ECG [14%], Holter monitoring [11%], or signal-averaged ECG [14%]) was more frequently observed than structural progression (n = 1 [3%] on CMR). All 5 patients (14%) with clinical ARVD/C diagnosis at last follow-up had an abnormal ECG or Holter monitor recording, and the only patient with an abnormal CMR already had an abnormal ECG at enrollment.ConclusionsOver a mean follow-up of 4 years, our study showed that: 1) almost one-third of at-risk relatives have electrical progression; 2) structural progression is rare; and 3) electrical abnormalities precede detectable structural changes. This information could be valuable in determining family screening protocols.

Background Diastolic function (DF) is not routinely assessed by cardiac MR (CMR), but is critical for assessment of common disease states such as heart failure or hypertrophy. At present, special pulse sequences (tagging, phase contrast) are necessary for CMR for diastolic function assessment. The purpose of this study was to assess cine CMR volumetric assessment of DF using a 3D modelbased analysis, in reference to 2D phase contrast and echocardiography (echo).

Background— The association of local electrogram features with scar morphology and distribution in nonischemic cardiomyopathy has not been investigated. We aimed to quantify the association of scar on late gadolinium-enhanced cardiac magnetic resonance with local electrograms and ventricular tachycardia circuit sites in patients with nonischemic cardiomyopathy. Methods and Results— Fifteen patients with nonischemic cardiomyopathy underwent late gadolinium-enhanced cardiac magnetic resonance before ventricular tachycardia ablation. The transmural extent and intramural types (endocardial, midwall, epicardial, patchy, transmural) of scar were measured in late gadolinium-enhanced cardiac magnetic resonance short-axis planes. Electroanatomic map points were registered to late gadolinium-enhanced cardiac magnetic resonance images. Myocardial wall thickness, scar transmurality, and intramural scar types were independently associated with electrogram amplitude, duration, and deflections in linear mixed-effects multivariable models, clustered by patient. Fractionated and isolated potentials were more likely to be observed in regions with higher scar transmurality ( P P 25% scar transmurality. Conclusions— Electrogram features are associated with scar morphology and distribution in patients with nonischemic cardiomyopathy. Previous knowledge of electrogram image associations may optimize procedural strategies including the decision to obtain epicardial access.

Catheter-based ablation techniques are extensively used for the treatment of atrial and ventricular arrhythmias. Preprocedural cardiac MRI is valuable for the management of these patients due to its ability to provide high-resolution anatomic mapping and tissue characterization in the absence of ionizing radiation. Delayed enhancement imaging can be used to localize the arrhythmia substrate within the chamber of interest prior to the procedure. There is growing evidence that delayed enhancement cardiac MRI may be useful in patients with atrial fibrillation in terms of treatment decisions and assessment of ablation efficacy.

Atrial fibrillation (AF) is an important cause of stroke. Given the morbidity and mortality associated with stroke, the risk stratification of patients based on left atrial appendage (LAA) characteristics is of great interest.To explore the association between LAA morphology and LAA characteristics including the extent of trabeculations, orifice diameter, and length with prevalent stroke in a large cohort of patients with drug refractory AF who underwent AF ablation to develop mechanistic insight regarding the risk of stroke.An institutional cohort of 1063 patients referred for AF ablation from 2003 to 2012 was reviewed to identify patients that underwent preprocedural cardiac computed tomography (CT). LAA morphology was characterized as chicken wing, cactus, windsock, or cauliflower by using previously reported methodology. Left atrial size and LAA trabeculations, morphology, orifice diameter, and length were compared between patients with prevalent stroke and patients without prevalent stroke.Of 678 patients with CT images, 65 (10%) had prior stroke or transient ischemic attack. In univariate analyses, prevalent heart failure (7.7% in cases vs 2.8% in controls; P = .033), smaller LAA orifice (2.26 ± 0.52 cm vs 2.78 ± 0.71 cm ; P.001), shorter LAA length (5.06 ± 1.17 cm vs 5.61 ± 1.17 cm; P.001), and extensive LAA trabeculations (27.7% vs 14.4%; P = .019) were associated with stroke. LAA morphologies were unassociated with stroke risk. In multivariable analysis, smaller LAA orifice diameter and extensive LAA trabeculations remained independently associated with thromboembolic events.The extent of LAA trabeculations and smaller LAA orifice diameter are associated with prevalent stroke and may mediate the previously described association of cauliflower LAA morphology with stroke.

The traditional description of the Triangle of Dysplasia in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C) predates genetic testing and excludes biventricular phenotypes.We analyzed Cardiac Magnetic Resonance (CMR) studies of 74 mutation-positive ARVD/C patients for regional abnormalities on a 5-segment RV and 17-segment LV model. The location of electroanatomic endo- and epicardial scar and site of successful VT ablation was recorded in 11 ARVD/C subjects. Among 54/74 (73%) subjects with abnormal CMR, the RV was abnormal in almost all (96%), and 52% had biventricular involvement. Isolated LV abnormalities were uncommon (4%). Dyskinetic basal inferior wall (94%) was the most prevalent RV abnormality, followed by basal anterior wall (87%) dyskinesis. Subepicardial fat infiltration in the posterolateral LV (80%) was the most frequent LV abnormality. Similar to CMR data, voltage maps revealed scar (0.5 mV) in the RV basal inferior wall (100%), followed by the RV basal anterior wall (64%) and LV posterolateral wall (45%). All 16 RV VTs originated from the basal inferior wall (50%) or basal anterior wall (50%). Of 3 LV VTs, 2 localized to the posterolateral wall. In both modalities, RV apical involvement never occurred in isolation.Mutation-positive ARVD/C exhibits a previously unrecognized characteristic pattern of disease involving the basal inferior and anterior RV, and the posterolateral LV. The RV apex is only involved in advanced ARVD/C, typically as a part of global RV involvement. These results displace the RV apex from the Triangle of Dysplasia, and provide insights into the pathophysiology of ARVD/C.

Background Echocardiography (ECHO) i su sed for diagnosis and management of hypertrophic cardiomyopathy (HCM). Morphologic diagnosis is based on the presence of myocardial thickness of >15mm in adults or a septum to posterior wall ratio of >1.5. Septal wall thickness (WT) >30 mm is one of several high risk features that are used to guide the decision for prophylactic implantable cardioverter-defibrillator (ICD) placement. Cardiac magnetic resonance imaging (CMR) offers improved contrast resolution over ECHO and precisely defines myocardial WT in HCM.CMR is used in suspected HCM when ECHO is inconclusive for diagnosis or when additional information is needed. We tested the hypothesis that there are differences in maximal left ventricular myocardial WT as measured by CMR and ECHO in subjects with HCM due to asymmetric septal hypertrophy (ASH). Methods 64 subjects with HCM and ASH pattern (mean age 51 years, range 18-88 years), underwent ECHO and CMR within the same day. Maximal WT by ECHO was measured on parasternal long axis view in the anteroseptal and the basilar posterior wall. WT by CMR was measured on the short axis view manually to obtain maximal dimensions in the same segments as those obtained by ECHO. Results Overall, mean maximal septal WT for all patients was less by CMR compared with ECHO, but not statistically

Aims This study aims to examine the association of clinical co-morbidities with the presence of left atrial (LA) late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). Previous studies have established the severity of LA LGE to be associated with atrial fibrillation (AF) recurrence following AF ablation. We sought to determine whether baseline clinical characteristics were associated with LGE extent among patients presenting for an initial AF ablation. Methods and results The cohort consisted of 179 consecutive patients with no prior cardiac ablation procedures who underwent pre-procedure LGE-CMR. The extent of LA LGE for each patient was calculated using the image intensity ratio, normalized to the mean blood pool intensity, corresponding to a bipolar voltage ≤0.3 mV. The association of LGE extent with baseline clinical characteristics was examined using non-parametric and multivariable models. The mean age of the cohort was 60.9 ± 9.6 years and 128 (72%) were male. In total, 56 (31%) patients had persistent AF. The mean LA volume was 118.4 ± 41.6 mL, and the mean LA LGE extent was 14.1 ± 10.4%. There was no association with any clinical variables with LGE extent by quartiles in the multivariable model. Extent of LGE as a continuous variable was positively, but weakly associated with LA volume in a multivariable model adjusting for age, body mass index, AF persistence, and left ventricular ejection fraction (1.5% scar/mL, P = 0.038). Conclusion In a cohort of patients presenting for initial AF ablation, the presence of pre-ablation LA LGE extent was weakly, but positively associated with increasing LA volume.

Background— The association of scar on late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) with local electrograms on electroanatomic mapping has been investigated. We aimed to quantify these associations to gain insights regarding LGE-CMR image characteristics of tissues and critical sites that support postinfarct ventricular tachycardia (VT). Methods and Results— LGE-CMR was performed in 23 patients with ischemic cardiomyopathy before VT ablation. Left ventricular wall thickness and postinfarct scar thickness were measured in each of 20 sectors per LGE-CMR short-axis plane. Electroanatomic mapping points were retrospectively registered to the corresponding LGE-CMR images. Multivariable regression analysis, clustered by patient, revealed significant associations among left ventricular wall thickness, postinfarct scar thickness, and intramural scar location on LGE-CMR, and local endocardial electrogram bipolar/unipolar voltage, duration, and deflections on electroanatomic mapping. Anteroposterior and septal/lateral scar localization was also associated with bipolar and unipolar voltage. Antiarrhythmic drug use was associated with electrogram duration. Critical sites of postinfarct VT were associated with >25% scar transmurality, and slow conduction sites with >40 ms stimulus-QRS time were associated with >75% scar transmurality. Conclusions— Critical sites for maintenance of postinfarct VT are confined to areas with >25% scar transmurality. Our data provide insights into the structural substrates for delayed conduction and VT and may reduce procedural time devoted to substrate mapping, overcome limitations of invasive mapping because of sampling density, and enhance magnetic resonance–based ablation by feature extraction from complex images.

Ablation for atrial fibrillation (AF) frequently requires multiple procedures to achieve durable restoration of sinus rhythm. Early studies have suggested that delayed enhancement magnetic resonance imaging (DE-MRI) of the left atrium (LA) can assist in performing repeat ablation procedures.The purpose of this study was to investigate the utility of DE-MRI in delineating regions of LA low voltage and PV reconnection sites in patients undergoing repeat PV isolation for recurrent AF.We enrolled 10 patients undergoing repeat ablation for AF recurrence to undergo preprocedural DE-MRI of the LA in conjunction with high-density voltage mapping (100 sites) of the LA during the ablation procedure. LA wall regions with hyperenhancement were segmented from DE-MRI images and retrospectively co-registered with the electroanatomic LA map. The association between scar on DE-MRI images and low-voltage regions of the LA was assessed, as was the association between scar gaps and electrogram-determined PV reconnection sites.Ten patients underwent successful DE-MRI imaging and repeat AF ablation without complication. In all 10 patients, the majority of PVs were found to have regained electrical continuity with the LA (30/37 PVs electrically active); all patients underwent successful reisolation of all PVs using standard ablation techniques. There was a significant association between scar identified by DE-MRI and low-voltage regions of the LA (-0.7±0.1 mV in scar regions; generalized estimating equations model clustered by patient, P.001). However, there was no association between scar gaps and PV reconnection sites.We demonstrate the co-registration of DE-MRI scar imaging and electroanatomic LA mapping, with agreement between regions of scar on DE-MRI and low voltage by mapping. However, at our center, this technique did not provide accurate information on the location of PV reconnection sites in patients undergoing repeat ablation for AF.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a clinically heterogeneous cardiomyopathy caused by desmosomal mutations that may lead to ventricular arrhythmias and sudden death ([1][1]). Among international studies describing structural phenotype in ARVD/C, significant

Thoracic endovascular aortic repair (TEVAR) has evolved as an alternative to open repair for a range of aortic pathology. The earliest endovascular repairs were limited to descending thoracic aortic pathology, but growing experience has resulted in the use of stents in the ascending aorta and aortic arch. This review presents the current literature pertaining to thoracic endoluminal stent repair, with emphasis on the role of intravenous contrast-enhanced multidetector computed tomography, the primary cross-sectional imaging modality used in these patients. Radiologists play an integral role in patient selection, procedural planning, and postprocedural follow-up.

Objectives To quantify resting myocardial blood flow (MBF) in the left ventricular (LV) wall of HCM patients and to determine the relationship to important parameters of disease: LV wall thickness, late gadolinium enhancement (LGE), T2-signal abnormalities (dark and bright signal), LV outflow tract obstruction and age. Materials and Methods Seventy patients with proven HCM underwent cardiac MRI. Absolute and relative resting MBF were calculated from cardiac perfusion MRI by using the Fermi function model. The relationship between relative MBF and LV wall thickness, T2-signal abnormalities (T2 dark and T2 bright signal), LGE, age and LV outflow gradient as determined by echocardiography was determined using simple and multiple linear regression analysis. Categories of reduced and elevated perfusion in relation to non- or mildly affected reference segments were defined, and T2-signal characteristics and extent as well as pattern of LGE were examined. Statistical testing included linear and logistic regression analysis, unpaired t-test, odds ratios, and Fisher’s exact test. Results 804 segments in 70 patients were included in the analysis. In a simple linear regression model LV wall thickness (p

Congenital absence of the pericardium is a rare entity, with less than 400 cases reported in the literature. Pericardial absence is typically left sided, which results in herniation of the great vessels or portions of the heart. Patients may be asymptomatic, typical for complete defects, or can present with various degrees of chest pain in the setting of partial absence and strangulation. The finding may be isolated or associated with complex heart disease. We present a number of cases of pericardial absence that show isolated right- and left-sided defects, as well as entities in the differential diagnosis. Early recognition may decrease morbidity and mortality, resulting from delay in proper treatment.

There is growing interest in the ability to monitor, track, and report exposure to radiation from medical imaging. Historically, however, dose information has been stored on an image-based dose sheet, an arrangement that precludes widespread indexing. Although scanner manufacturers are beginning to include dose-related parameters in the Digital Imaging and Communications in Medicine (DICOM) headers of imaging studies, there remains a vast repository of retrospective computed tomographic (CT) data with image-based dose sheets. Consequently, it is difficult for imaging centers to monitor their dose estimates or participate in the American College of Radiology (ACR) Dose Index Registry. An automated extraction software pipeline known as Radiation Dose Intelligent Analytics for CT Examinations (RADIANCE) has been designed that quickly and accurately parses CT dose sheets to extract and archive dose-related parameters. Optical character recognition of information in the dose sheet leads to creation of a text file, which along with the DICOM study header is parsed to extract dose-related data. The data are then stored in a relational database that can be queried for dose monitoring and report creation. RADIANCE allows efficient dose analysis of CT examinations and more effective education of technologists, radiologists, and referring physicians regarding patient exposure to radiation at CT. RADIANCE also allows compliance with the ACR's dose reporting guidelines and greater awareness of patient radiation dose, ultimately resulting in improved patient care and treatment.

Imaging centers nationwide are seeking innovative means to record and monitor computed tomography (CT)-related radiation dose in light of multiple instances of patient overexposure to medical radiation. As a solution, we have developed RADIANCE, an automated pipeline for extraction, archival, and reporting of CT-related dose parameters. Estimation of whole-body effective dose from CT dose length product (DLP)--an indirect estimate of radiation dose--requires anatomy-specific conversion factors that cannot be applied to total DLP, but instead necessitate individual anatomy-based DLPs. A challenge exists because the total DLP reported on a dose sheet often includes multiple separate examinations (e.g., chest CT followed by abdominopelvic CT). Furthermore, the individual reported series DLPs may not be clearly or consistently labeled. For example, "arterial" could refer to the arterial phase of the triple liver CT or the arterial phase of a CT angiogram. To address this problem, we have designed an intelligent algorithm to parse dose sheets for multi-series CT examinations and correctly separate the total DLP into its anatomic components. The algorithm uses information from the departmental PACS to determine how many distinct CT examinations were concurrently performed. Then, it matches the number of distinct accession numbers to the series that were acquired and anatomically matches individual series DLPs to their appropriate CT examinations. This algorithm allows for more accurate dose analytics, but there remain instances where automatic sorting is not feasible. To ultimately improve radiology patient care, we must standardize series names and exam names to unequivocally sort exams by anatomy and correctly estimate whole-body effective dose.

Quantitative and descriptive imaging data are a vital component of the radiology report and are frequently of paramount importance to the ordering physician. Unfortunately, current methods of recording these data in the report are both inefficient and error prone. In addition, the free-text, unstructured format of a radiology report makes aggregate analysis of data from multiple reports difficult or even impossible without manual intervention. A structured reporting work flow has been developed that allows quantitative data created at an advanced imaging workstation to be seamlessly integrated into the radiology report with minimal radiologist intervention. As an intermediary step between the workstation and the reporting software, quantitative and descriptive data are converted into an extensible markup language (XML) file in a standardized format specified by the Annotation and Image Markup (AIM) project of the National Institutes of Health Cancer Biomedical Informatics Grid. The AIM standard was created to allow image annotation data to be stored in a uniform machine-readable format. These XML files containing imaging data can also be stored on a local database for data mining and analysis. This structured work flow solution has the potential to improve radiologist efficiency, reduce errors, and facilitate storage of quantitative and descriptive imaging data for research.

In the March 17, 2015 issue of the Journal , Etoom et al. [(1)][1] reported interesting findings about the role of cardiovascular magnetic resonance (CMR) for diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) in children. The results of Etoom et al. [(1)][1] are

To retrospectively assess the findings of idiopathic eosinophilic esophagitis (IEE) at barium studies and determine the frequency of the ringed esophagus in patients with this condition.The institutional review board approved all aspects of this retrospective study and did not require informed consent from patients whose records were included in the study. The study was compliant with the Health Insurance Portability and Accountability Act. A review of the pathology and radiology databases at the authors' institution revealed 14 patients (11 men and three women; mean age, 41.3 years) with IEE (defined as more than 20 eosinophils per high-power field in biopsy specimens) who had undergone barium studies and endoscopy. The radiographs were reviewed for strictures, esophagitis, or other abnormalities. The endoscopic reports, clinical records, and laboratory data were also reviewed and compared with the radiographic findings.Seven of the 14 patients (50%) had a history of allergies, and two of nine patients with complete blood cell counts (22%) had peripheral eosinophilia. Thirteen patients (93%) had dysphagia, six (43%) had food impactions, and six (43%) had reflux symptoms. Ten patients (71%) had a total of 11 strictures at barium studies (two in the upper part of the esophagus, two in the middle part, three in the distal part, one in the middle and distal parts, and three at the gastroesophageal junction). The strictures had a mean length of 5.1 cm. In seven patients (50%), the strictures contained multiple fixed ringlike indentations that produced a ringed esophagus. The ringlike indentations appeared as multiple, fixed, closely spaced, concentric rings traversing the stricture. Four patients (28%) had esophagitis. Of 13 patients who underwent recumbent imaging, 10 (77%) had hiatal hernias and nine (69%) had reflux. Eight of the 10 patients (80%) with strictures underwent endoscopic dilation procedures, which resulted in only temporary relief of dysphagia.The findings suggest that most patients with IEE have esophageal strictures, often with distinctive ringlike indentations that produce a ringed esophagus.

Background Recurrence of atrial fibrillation (AF) after catheter ablation has been associated with left atrial (LA) fibrosis. However, arbitrary units of measure limit the interpatient comparison of delayed enhancement intensity. We sought to quantify LA fibrosis using a novel normalized measure: the image intensity ratio (IIR) of late-gadolinium enhanced magnetic resonance imaging (LGE-MRI). Methods LGE-MRI images (1.5 Tesla) were obtained in 30 patients (37% female, mean age 62 ± 8) prior to first (60%), second (23%), or third (17%) ablation procedure for AF. Multiplanar reformatted images were reconstructed from the stack of 3-D axial image data. Epicardial and endocardial contours were manually drawn around LA myocardium. The IIR, defined as local LA myocardial signal intensity divided by the mean LA blood pool image intensity, was measured for each of 20 sectors created on contiguous axial planes through the LA. Electroanatomic map (EAM) points were registered to the corresponding LGE-MRI images using custom software. Results A total of 2569 EAM points were analyzed. The average bipolar voltage was 0.9 ± 1.0 mV (0.5 between and 0.9 within patient standard deviation). Local IIR was strongly associated with bipolar voltage (Figure, P P Conclusions Higher IIR values were observed in areas with lower bipolar voltage on EAM. The IIR obtained from LGE-MRI may improve the quantification of LA fibrosis

Hyperleptinemia is a common feature of pregnancy in mammals. The source of increased plasma leptin is uncertain. We examined leptin secretory rates in vitro to test the hypothesis that leptin secretion is upregulated during pregnancy. Two species of insectivorous bats were examined, Myotis lucifugus and Eptesicus fuscus, because of their unique reproductive cycle. Body mass and plasma leptin significantly increased with gestation and decreased during lactation. Adiposity increased in midgestation, then decreased in late gestation and lactation and was not significantly correlated with plasma leptin in pregnant or early lactating individuals. Leptin secretion in vitro per gram of adipose tissue tended to increase with gestation but was not significantly correlated with plasma leptin in the same individuals. Leptin secretion from placentae, however, increased with gestation and was significantly correlated with plasma leptin from the same individuals. In suckling pups, plasma leptin was high shortly after birth, then decreased to low levels that were not correlated with adiposity thereafter. We conclude that in bats, the placenta is a major source of circulating leptin during pregnancy, and that adiposity and plasma leptin levels are decoupled during three different periods of intense metabolic demand (pregnancy, early lactation, and neonatal growth).

Background Patients with hypertrophic cardiomyopathy (HCM) develop left ventricular outflow tract (LVOT) obstruction due to combination of asymmetric septal hypertrophy and systolic anterior motion of the mitral leaflet. Degree of LVOT obstruction is an important predictor in patient symptoms and clinical outcome. LVOT obstruction is currently assessed by Doppler echocardiography (echo) using peak velocity to calculate pressure gradient in the LVOT. 4D phase contrast (4D PC) MRI is an emerging technique for quantification of regional flow and velocity. 4D PC MRI is a 3 dimensional, 3 directionally encoded, time resolved (cine) velocity acquisition. It has the advantage of providing full 3D volume coverage and flexibility of retrospective analysis of flow at any location and in any imaging plane. In this preliminary study, we

Background Left atrial (LA) late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) has varying protocols, which may limit interstudy comparisons. This study evaluates whether changes in image acquisition and reconstruction parameters affect quantification of LA LGE MRI. Methods A total of 200 LGE MRI scans were prepared using various techniques from 5 subjects. 3D respiratory and ECG-gated LGE images were acquired at 15, 20, 25, and 30 minutes after contrast. Multiplanar reconstructions (MPR) and maximum intensity projections (MIP) were created from 3D data at various slice thicknesses. LA LGE was quantified with image intensity ratio (IIR, atrial wall signal intensity divided by blood pool). Mean IIR was calculated for the entire LA as a metric of LGE burden. Additionally, in 42 consecutive preablation patients, local IIR values from 3.5-mm MPR and MIP reconstructions were separately registered to LA electroanatomic voltage maps (EAM) obtained prior to ablation procedure. Results Multitime point LGE-MRI showed a rise in baseline mean IIR of 0.5% ± 0.1% per minute ( P P P P Conclusions Variations in timing of acquisition, image reconstruction methods, and slice thickness result in changes in LA LGE quantity.

PURPOSE: Computed tomography(CT) technology has rapidly evolved. Phantom studies show higher radiation doses with increasing detector rows. However scanner‐based dose‐reduction techniques have also evolved. Given these opposing trends that impact patient dose it is unclear whether doses increased have or decreased over time. Using an automated dose information extraction tool we analyzed trends in radiation doses over time for abdominal and pelvic examinations at our institution. METHOD AND MATERIALS: Radiation dose (total DLP) from 1716 abdominal and pelvic CT examinations performed between 2003 and 2010 were analyzed. Examinations were performed on 6 MDCT scanners ranging from 4 to 64 detectors. Dose data from protocol sheets was extracted using a novel extraction system. RESULTS: Average DLP for CT examinations of the abdomen and pelvis performed in 2003 was 728.9 +/−278 mGy‐cm. Average DLP for examinations performed in 2010 was 1034 +/− 458 mGy‐cm a 41.8% increase. For a 16 slice scanner in constant use since 2003 average DLP increased from 728.9 +/− 278 mGy‐cm in 2003 to 1004 +/− 421 mGy‐cm in 2010 a 37.7% increase. For abdominal and pelvic examinations from the year 2010 average DLP for exams performed on 16‐slice scanners (2 total) was 1094 +/− 478 mGy‐cm. The average DLP for examinations performed on 64‐slice scanners (3 total) was 1245 +/− 598 mGy‐cm which is an average 13.8% higher dose. CONCLUSIONS: Average CT radiation dose has increased over time. Scanners with greater numbers of detector rows delivered a higher radiation dose. Patient radiation doses for abdominal and pelvic examinations performed on a given scanner also increased over time. The upward trend in dose is likely due to a combination of hardware factors protocol changes and potentially changes in the patient population. Knowledge of these trends is important for effective implementation of dose reduction protocols and quality assurance.