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Numerous entities, both structural and pathologic, can manifest as a contrast material- or blood-filled cardiac outpouching at imaging. These outpouchings often resemble one another and are frequently unfamiliar to imagers and clinicians, creating uncertainty when detected. Furthermore, the diagnostic criteria for conditions such as hernia, aneurysm, pseudoaneurysm, and diverticulum have not been consistently applied in studies and reports cited in the literature describing these outpouchings, adding to the confusion among general and cardiothoracic imagers. Pouches and outpouchings are commonly found incidentally on thoracic and abdominal CT scans obtained for other reasons. Many pouches and outpouchings can be confidently diagnosed or ignored at routine imaging, whereas others may require further evaluation with electrocardiographically gated CT, cardiac MRI, or echocardiography for a more definitive diagnosis. It is easiest to group and diagnose these entities on the basis of their cardiac chamber location or their involvement with the interatrial and interventricular septa. Ancillary features, such as motion, morphology, neck and body size, presence or absence of thrombus, and late gadolinium enhancement characteristics, are important in reaching a correct diagnosis. The aim of this article is to provide a practical guide to pouches and outpouchings of the heart. Each entity is defined according to its cause, imaging characteristics, clinical significance, and relevant associated findings. Mimics of cardiac pouches and outpouchings such as the Bachmann bundle, atrial veins, and thebesian vessels also are briefly discussed. Quiz questions for this article are available in the supplemental material. ©RSNA, 2023.

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[This corrects the article DOI: 10.1155/2014/289720.].

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Left atrial appendage (LAA) mechanical exclusion is being investigated for nonpharmacologic stroke risk reduction in selected patients with atrial fibrillation. There are multiple potential approaches in various stages of development and clinical application, each of which depends on specific cardiothoracic anatomic characteristics for optimal performance. Multiple imaging modalities can be utilized for application of this technology, with transesophageal echocardiography used for intraprocedural guidance. Cardiovascular computed tomographic angiography can act as a virtual patient avatar, allowing for the assessment of cardiac structures in the context of surrounding cardiac, coronary vascular, thoracic vascular, and visceral and skeletal anatomy, aiding preprocedural decision-making, planning, and follow-up. Although transesophageal echocardiography is used for intraprocedural guidance, computed tomographic angiography may be a useful adjunct for preprocedure assessment of LAA sizing and anatomic obstacles or contraindications to deployment, aiding in the assessment of optimal approaches. Potential approaches to LAA exclusion include endovascular occlusion, epicardial ligation, primary minimally invasive intercostal thoracotomy with thoracoscopic LAA ligation or appendectomy, and minimally invasive or open closure as part of cardiothoracic surgery for other indications. The goals of these procedures are complete isolation or exclusion of the entire appendage without leaving a residual appendage stump or residual flow with avoidance of acute or chronic damage to surrounding cardiovascular structures. The cardiovascular imager plays an important role in the preprocedural and postprocedural assessment of the patient undergoing LAA exclusion.

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OBJECTIVE. The purpose of this article is to review the nascent field of radiomics in cardiac MRI. CONCLUSION. Cardiac MRI produces a large number of images in a fairly inefficient manner with sometimes limited clinical application. In the era of precision medicine, there is increasing need for imaging to account for a broader array of diseases in an efficient and objective manner. Radiomics, the extraction and analysis of quantitative imaging features from medical imaging, may offer potential solutions to this need.

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The AngioVac system, designed for suction during extracorporeal bypass, is used to aspirate masses, thrombi, and other undesirable material from the cardiovascular system. To date, it has been used extensively in the venous system and right side of the heart; however, its use in the arterial system has been limited because of smaller vessel sizes and the requirement for a 26F sheath. We report the case of a 45-year-old woman with a history of angiosarcoma who presented with acute embolic events that affected her spleen and lower extremities. We removed a large mobile mass en bloc from her distal thoracic aorta by using the AngioVac system as an alternative to surgical resection. The patient recovered with no recurrence. We discuss the benefits and challenges of using the AngioVac within small vessels of the arterial system.

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OBJECTIVE. The objective of this study was to determine if moderate to severe tricuspid regurgitation (TR) can be predicted on routine non-ECG-gated CT images of the chest with contrast agent. MATERIALS AND METHODS. Non-ECG-gated CT images of the chest in 674 people who had undergone echocardiography within 24 hours of CT were retrospectively reviewed. CT images were reviewed, and measurements of the tricuspid annular diameter were recorded. Echocardiogram reports were independently reviewed, and the presence and severity of TR was recorded. TR was graded in a multiparametric approach using a combination of qualitative, quantitative, and objective measures. TR grades of either "moderate" or "severe" were considered significant, and grades reported as "no regurgitation," "trace," "trivial," or "mild" were considered insignificant. RESULTS. The overall prevalence of significant (moderate or severe) TR was 15.0% (10.7% prevalence in men and 19.8% in women). Using ≥ 41 mm as a cut point on CT, the prediction accuracy reached an AUC of 0.92 (95% CI, 0.89-0.96). Specificity was 96.5% (95% CI, 95.0-97.9%), sensitivity was 75.7% (95% CI, 67.6-83.8%), positive predictive value was 80.2%, and negative predictive value was 95.5%. CONCLUSION. Using a cut point of ≥ 41 mm, measurement of the tricuspid valve annulus on routine CT of the chest can predict moderate to severe TR with a specificity of 96.5% and sensitivity of 75.7%. Measurements below threshold had a 95.5% negative predictive value. Tricuspid annular diameter can be measured on routine contrast-enhanced CT images of the chest, and, when above threshold, further evaluation with echocardiography should be recommended.

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Cardiovascular computed tomographic angiography (CCTA) 3-D thoracic reconstruction can serve as a "virtual patient avatar" providing surgical views for approach to complex anomalous coronary artery anatomy. Images demonstrated a single coronary artery ostium arising from the right aortic sinus with trifurcation into a prepulmonic left anterior descending coronary artery (LAD), an interarterial circumflex with a subsequent intraseptal course, and normal course of the right coronary artery. Virtual 3-D CCTA reconstructions were important to planning an incisional plane for surgical correction.

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Treatment of thoracic aortic dissection remains highly challenging and is rapidly evolving. Common classifications of thoracic aortic dissection include the Stanford classification (types A and B) and the DeBakey classification (types I to III), as well as a new supplementary classification geared toward endovascular decision making. By using various imaging techniques, the extent of the dissection, the location of the primary intimal tear, the shape of the aortic arch, and the zonal involvement of the aortic arch-factors that affect the treatment strategy-can easily be identified. Thoracic endovascular aortic repair (TEVAR) is generally performed in two groups of patients: (a) those with a surgically repaired type A dissection, and (b) those with a complicated type B dissection. Several imaging findings can help predict the course of remodeling of the dissected aorta after a repaired type A dissection and TEVAR. A spectrum of imaging findings exist with regard to favorable (positive) or failing (negative) remodeling. A schematic model with imaging support allows the classification of important causes of failing remodeling into proximal and distal groups, on the basis of the origin of the refilling of the false lumen and the underlying pathophysiology of pressurization. Refilling of the false lumen of the aorta after repair of a type A dissection is usually secondary to a persistent intimal tear at the aortic arch, a leak of the distal graft anastomosis, or refilling from the false lumen of a dissected aortic arch vessel. After TEVAR, false lumen refilling is most commonly due to an incomplete seal of the proximal landing related to the aortic tortuosity, an arch branch stump, a supra-arch chimney stent, or the TEVAR technique. Online supplemental material is available for this article. ©RSNA, 2018.

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Knowledge of the anatomy of the membranous septum, as a surrogate to the location of the atrioventricular conduction axis, is a prerequisite for those undertaking transcatheter implantation of the aortic valve (TAVI). Equally important is its relationship of the virtual basal ring. This feature, however, has yet to be adequately described in the living heart. We analyzed computed tomographic angiographic datasets from 107 candidates (84.1 ± 5.2 years, 68% women) for TAVI. Using multiplanar reconstructions, we measured the height and width of the membranous septum, and the distances of its superior and inferior margins from the virtual basal ring plane. We also assessed the extent of wedging of the aortic root between the mitral valve and the ventricular septum. Mean heights and widths of the membranous septum were 6.6 ± 2.0, and 10.2 ± 3.1 mm, respectively, with its size significantly associated with that of the aortic root (P < 0.05). Its superior and inferior margins were 4.5 ± 2.3 and 2.1 ± 2.1 mm, respectively, from the plane of the basal ring. The inferior distance, the surrogate for the adjacency of the atrioventricular conduction axis, was ≤ 5mm in 91% of the patients. Deeper wedging of the aortic root was independently correlated with a shorter inferior distance (ß = 0.0569, P = 0.0258). The membranous septum is appreciably closer to the virtual basal ring than previously appreciated. These findings impact on estimations of the risk of damage to the atrioventricular conduction axis during TAVI. Clin. Anat. 31:525-534, 2018. © 2018 Wiley Periodicals, Inc.

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OBJECTIVE: It is intuitive to suggest that knowledge of the variation in the anatomy of the aortic root may influence the outcomes of transcatheter implantation of the aortic valve (TAVI). We have now assessed such variation. METHODS: We used 26 specimens of normal hearts and 78 CT data sets of adults with a mean age of 64±15 years to measure the dimensions of the membranous septum and to assess any influence played by rotation of the aortic root, inferring the relationship to the atrioventricular conduction axis. RESULTS: The aortic root was positioned centrally in the majority of both cohorts, although with significant variability. For the cadaveric hearts, 14 roots were central (54%), 4 clockwise-rotated (15%) and 8 counterclockwise-rotated (31%). In the adult CT cohort, 44 were central (56%), 21 clockwise-rotated (27%) and 13 counterclockwise-rotated (17%). A mean angle of 15.5° was measured relative to the right fibrous trigone in the adult CT cohort, with a range of -32° to 44.7°. The dimensions of the membranous septum were independent of rotation. Fibrous continuity between the membranous septum and the right fibrous trigone increased with counterclockwise to clockwise rotation, implying variation in the relationship to the atrioventricular conduction axis. CONCLUSIONS: The central fibrous body is wider, providing greater fibrous support, in the setting of clockwise rotation of the aortic root. Individuals with this pattern may be more vulnerable to conduction damage following TAVI. Knowledge of such variation may prove invaluable for risk stratification.

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The pulmonary veins carry oxygenated blood from the lungs to the heart, but their importance to the radiologist extends far beyond this seemingly straightforward function. The anatomy of the pulmonary veins is variable among patients, with several noteworthy variant and anomalous patterns, including supernumerary pulmonary veins, a common ostium, anomalous pulmonary venous return, and levoatriocardinal veins. Differences in pulmonary vein anatomy and the presence of variant or anomalous anatomy can be of critical importance, especially for preoperative planning of pulmonary and cardiac surgery. The enhancement or lack of enhancement of the pulmonary veins can be a clue to clinically important disease, and the relationship of masses to the pulmonary veins can herald cardiac invasion. The pulmonary veins are also an integral part of thoracic interventions, including lung transplantation, pneumonectomy, and radiofrequency ablation for atrial fibrillation. This fact creates a requirement for radiologists to have knowledge of the pre- and postoperative imaging appearances of the pulmonary veins. Many of these procedures are associated with important potential complications involving the pulmonary veins, for which diagnostic imaging plays a critical role. A thorough knowledge of the pulmonary veins and a proper radiologic approach to their evaluation is critical for the busy radiologist who must incorporate the pulmonary veins into a routine "search pattern" at computed tomography (CT) and magnetic resonance imaging. This article is a comprehensive CT-based imaging review of the pulmonary veins, including their embryology, anatomy (typical and anomalous), surgical implications, pulmonary vein thrombosis, pulmonary vein stenosis, pulmonary vein pseudostenosis, and the relationship of tumors to the pulmonary veins. Online supplemental material is available for this article. ©RSNA, 2017.

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The fibrous skeleton is concentrated at the base of the ventricular mass. It provides electrical insulation at the atrioventricular level and fibrous continuity for the leaflets of the mitral, aortic, and tricuspid valves. Its components include the fibrous trigones, the fibrous area of aortic-mitral continuity, the subvalvar collar of the mitral valve, the membranous septum, the interleaflet triangles, the tendon of Todaro, and likely the conus ligament. The majority of the mitral annulus is fibrous, but the only true fibrous part of the tricuspid annulus is where the valvar leaflets are attached to the central fibrous body. At the aortic annulus, the fibrous elements support only the noncoronary aortic sinus and parts of the right and left coronary sinuses. The ring-shaped annulus of the arterioventricular valves as localized with imaging techniques (imaging annulus) differs from the crown-shaped hemodynamic annulus of the arterial valves. The imaging annulus corresponds to the plane passing through the nadirs of the hinge-lines of the leaflets. The hinges of the pulmonary valve are not part of the fibrous skeleton. Computed tomography (CT) and magnetic resonance (MR) imaging are excellent modalities for evaluation of the anatomy, physiologic variations, and pathologic conditions of the fibrous skeleton. The submillimeter isotropic three-dimensional datasets obtained with CT and the high contrast resolution of MR imaging are the main advantages of these modalities in assessing anatomy. The function of the valves and associated annuli can best be studied with MR imaging. Pathologic conditions involving the area, including paravalvar leaks, abscesses, perforation, and pseudoaneurysms, usually occur as a complication of infective endocarditis or extensive calcifications after valvar surgery. MR imaging and CT can demonstrate these lesions equally well. CT is the preferred technique for showing the extent of calcifications in the fibrous skeleton. Large calcifications involving the central fibrous body can cause heart block by interfering with the normal function of the His bundle and its branches. ©RSNA, 2017.

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OBJECTIVE: Various degrees of aortic valve rotation may be seen in individuals with no history of congenital cardiovascular malformations, but its association with aortic sizes has not been studied. METHODS: Gated computed tomographic (CT angiograms in 217 patients were studied (66.7±15; 22-97 years old)). Aortic diameters were determined at 5 anatomic locations. The length of the aorta from sinus to left subclavian artery was measured. The angle of valve rotation was recorded by measuring the angle between a line connecting the midpoint of the non-coronary sinus to the anterior commissure and another line along the interatrial septum. Rotation angles were correlated with aortic measurements. Patients were separated into two groups based on aortic sizes and into three groups based on age. The threshold for aortic dilatation was set at maximum ascending aorta diameter ≥40mm (≥21mm body surface area [BSA] indexed). RESULTS: No significant difference in rotation angles was seen between the three age groups or between genders. Rotation angles were significantly correlated with maximal, average, and BSA adjustment of the aortic root and ascending aortic measurements. The aortic root angles were significantly different between the dilated versus nondilated aortas. There was no significant association between the rotation angles and age, length of ascending aorta, or diameters of descending aorta. Multivariate adaptive regression splines showed 25° of aortic root rotation as the diagnostic cut off for ascending aorta dilation. Above the 25° rotation, every 10° of increasing rotation was associated with a 3.78±0.87mm increase in aortic diameter (p<0.01) and a 1.73±0.25 times increased risk for having a dilated aorta (p<0.01). CONCLUSION: Rotation angles of the aortic valve may be an independent non-invasive imaging marker for dilatation of the ascending aorta. Patients with increased rotation angle of the aortic valve may have higher risk for development or acceleration of an ascending aortic dilatation.

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PURPOSE: To determine the feasibility of measuring increases in myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) on a per-segment basis using arterial spin labeled (ASL) magnetic resonance imaging (MRI) with adenosine vasodilator stress in normal human myocardium. MATERIALS AND METHODS: Myocardial ASL scans at rest and during adenosine infusion were incorporated into a routine 3T MR adenosine-induced vasodilator stress protocol and were performed in 10 healthy human volunteers. Myocardial ASL was performed using single-gated flow-sensitive alternating inversion recovery (FAIR) tagging and balanced steady-state free precession (bSSFP) imaging at 3T. A T2 -prep blood oxygen level-dependent (BOLD) SSFP sequence was used to concurrently assess segmental myocardial oxygenation with BOLD signal intensity (SI) percent change in the same subjects. RESULTS: There was a statistically significant difference between MBF measured by ASL at rest (1.75 ± 0.86 ml/g/min) compared to adenosine stress (4.58 ± 2.14 ml/g/min) for all wall segments (P < 0.0001), yielding a per-segment MPR of 3.02 ± 1.51. When wall segments were divided into specific segmental myocardial perfusion territories (ie, anteroseptal, anterior, anterolateral, inferolateral, inferior, and inferoseptal), the differences between rest and stress regional MBF for each territory remained consistently statistically significant (P < 0.001) after correcting for multiple comparisons. CONCLUSION: This study demonstrates the feasibility of measuring MBF and MPR on a segmental basis by single-gated cardiac ASL in normal volunteers. Second, this study demonstrates the feasibility of performing the ASL sequence and T2 -prepared SSFP BOLD imaging during a single adenosine infusion. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:413-420.

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PURPOSE: Cardiac motion is a dominant source of physiological noise (PN) in myocardial arterial spin labeled (ASL) perfusion imaging. This study investigates the sensitivity to heart rate variation (HRV) of double-gated myocardial ASL compared with the more widely used single-gated method. METHODS: Double-gating and single-gating were performed on 10 healthy volunteers (n = 10, 3F/7M; age, 23-34 years) and eight heart transplant recipients (n = 8, 1F/7M; age, 26-76 years) at rest in the randomized order. Myocardial blood flow (MBF), PN, temporal signal-to-noise ratio (SNR), and HRV were measured. RESULTS: HRV ranged from 0.2 to 7.8 bpm. Double-gating PN did not depend on HRV, while single-gating PN increased with HRV. Over all subjects, double-gating provided a significant reduction in global PN (from 0.20 ± 0.15 to 0.11 ± 0.03 mL/g/min; P = 0.01) and per-segment PN (from 0.33 ± 0.23 to 0.21 ± 0.12 mL/g/min; P < 0.001), with significant increases in global temporal SNR (from 11 ± 8 to 18 ± 8; P = 0.02) and per-segment temporal SNR (from 7 ± 4 to 11 ± 12; P < 0.001) without significant difference in measured MBF. CONCLUSION: Single-gated myocardial ASL suffers from reduced temporal SNR, while double-gated myocardial ASL provides consistent temporal SNR independent of HRV. Magn Reson Med 77:1975-1980, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

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Acute coronary syndrome (ACS) is a frequent cause of hospitalization and coronary interventions. Cardiac magnetic resonance (MR) imaging is an increasingly used technique for initial work-up of chest pain and early post-reperfusion and follow-up evaluation of ACS to identify patients at high risk of further cardiac events. Cardiac MR imaging can evaluate with accuracy a variety of prognostic indicators of myocardial damage, including regional myocardial dysfunction, infarct distribution, infarct size, myocardium at risk, microvascular obstruction, and intramyocardial hemorrhage in both acute setting and later follow-up examinations. In addition, MR imaging is useful to rule out other causes of acute chest pain in patients admitted to the emergency department. In this article, a brief explanation of the pathophysiology, classification, and treatment options for patients with ACS will be introduced. Indications of cardiac MR imaging in ACS patients will be reviewed and specific cardiac MR protocol, image interpretation, and potential diagnostic pitfalls will be discussed. © RSNA, 2017 Online supplemental material is available for this article.

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The septal atrioventricular junction is a centrally located region of the heart where the septal components of the atria and ventricles meet the aortic, mitral, and tricuspid valves. Important structures in this region include the membranous septum, the central fibrous body, the Koch triangle, the inferior pyramidal space, and the base of the interventricular septum. This small area is the home of the atrioventricular node and the atrioventricular conduction axis and has enormous importance to electrophysiologists owing to its prime role in the conduction system of the heart. The atrioventricular node lies within the triangle of Koch; and the atrioventricular bundle, or bundle of His, exits the atrioventricular node and penetrates the right fibrous trigone and runs underneath the membranous septum. The septal atrioventricular junction is a common location for intracardiac shunts such as membranous and perimembranous septal defects. Imaging classification of these defects can have important implications before surgical closure, because the atrioventricular conduction axis passes along the posteroinferior margin of most perimembranous defects. Extracardiac inflammatory and malignant pathologic conditions can extend from the mediastinum toward the inferior pyramidal space in this region through the epicardial fat planes. Although the anatomic structures are complicated, the components can be shown in exquisite detail with computed tomography (CT). In this review, the anatomic boundaries and important anatomic landmarks are examined with CT and magnetic resonance imaging. Also described are the anatomic variants of the membranous septum pertinent to percutaneous aortic valve implantation, the vascular anatomic variants, and commonly encountered pathologic conditions related to the septal atrioventricular junction. ©RSNA, 2016.

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OBJECTIVE: This study was designed to evaluate the severity of subclinical atherosclerosis in patients with asymptomatic impaired fasting glucose (IFG) compared to those with diabetes mellitus (DM) and normal fasting glucose (NFG), as measured by coronary computed tomographic angiography (CCTA). DESIGN: Subjects were divided into three groups: NFG (<100 mg/dL), IFG (100-125 mg/dL) and DM. Coronary artery calcium on non-contrast CT and plaque analysis on CCTA were performed. SETTING: University hospital, single centre. PARTICIPANTS: 216 asymptomatic participants prospectively underwent CCTA for the evaluation of coronary artery disease (CAD). PRIMARY AND SECONDARY OUTCOME MEASURES: Atherosclerotic plaque burden in IFG compared to NFG patients. RESULTS: 2664 segments were analysed in 120 NFG, 44 IFG and 52 DM participants. The mean calcium scores were 178±395, 259±510 and 414±836 for NFG, IFG and DM, respectively (p=0·037). The mean plaque burdens in the NFG, IFG and DM groups were 0.31±0.45, 0.50±0.69 and 0.68±0.69, respectively (p=0·0007). A greater proportion of patients with DM (19/52, 36.5%) and IFG (13/44, 29.5%) had obstructive CAD compared to those with NFG (16/120, 13.3%) (p=0.0015). The number of segments with severe disease was significantly higher in the DM (60/637, 9.4%) and IFG (42/539, 7.8%) groups compared to that in the NFG group (34/1488, 2.3%) (p=0.0001). CONCLUSIONS: (1) IFG and DM have significantly higher, but comparable, calcium scores, plaque burden and obstructive CAD compared to NFG in asymptomatic individuals. (2) Pending corroboration by other reports, more intensive efforts may be devoted to the evaluation and treatment of patients with IFG.

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This case report demonstrates development and progressive enlargement of multiple pancreaticoduodenal arcade pseudoaneurysms using computed tomography angiographies over a period of 5 weeks after abdominal trauma. The mechanism of pseudoaneurysm formation, as shown by serial imaging, attributed to preexisting celiac axis stenosis by the median arcuate ligament, posttraumatic celiac artery dissection, and secondary occlusion of proper hepatic artery resulting in elevation of pressure and flow in the pancreaticoduodenal arcade and rupture of small arterial branches. Successful pseudoaneurysm occlusion was achieved through arterial embolization.

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The levoatriocardinal vein is a very rare but clinically important intrathoracic venous anomaly that connects the systemic (cardinal) and pulmonary venous channels. We report 4 adults with pulmonary-systemic venous communications that can explain the morphology of the extracardiac interatrial shunting through the persistent levoatriocardinal vein. We discuss the imaging features of the 2 types of such communications: direct connection of the levoatriocardinal vein (1) with the left atrium and (2) with the left superior pulmonary vein in the absence of obstructive left heart disease. Accurate characterization of these diagnostically challenging cases is important because in addition to hemodynamic imbalance they are at risk of paradoxical embolism. Computed tomography and magnetic resonance imaging are noninvasive imaging techniques that should play increasingly important roles in the evaluation of these anomalies.

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