Crystal R. Bonnichsen

CT and MR Imaging of the Mitral Valve: Radiologic-Pathologic Correlation

Computed tomography (CT) and magnetic resonance (MR) imaging are increasingly important adjuncts to echocardiography for the evaluation of mitral valve disease. The mitral valve may be involved in various acquired or congenital conditions with resultant regurgitation or stenosis, and many of these conditions can be identified with CT or MR imaging. In addition, CT is useful for detecting and monitoring postoperative complications after mitral valve repair or replacement. As the use of CT and MR imaging increases, awareness of the CT and MR imaging appearances of the normal mitral valve and the various disease processes that affect it may foster recognition of unsuspected mitral disease in patients undergoing imaging for other purposes. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.306105518/-/DC1.

Magnetic Resonance Elastography. A Novel Technique for the Detection of Hepatic Fibrosis and Hepatocellular Carcinoma After the Fontan Operation

OBJECTIVE To evaluate the utility of magnetic resonance elastography (MRE) in screening patients for hepatic fibrosis, cirrhosis, and hepatocellular carcinoma after the Fontan operation. PATIENTS AND METHODS Hepatic MRE was performed in conjunction with cardiac magnetic resonance imaging in patients who had undergone a Fontan operation between 2010 and 2014. Liver stiffness was calculated using previously reported techniques. Comparisons to available clinical, laboratory, imaging, and histopathologic data were made. RESULTS Overall, 50 patients at a median age of 25 years (range, 21-33 years) who had undergone a Fontan operation were evaluated. The median interval between Fontan operation and MRE was 22 years (range, 16-26 years). The mean liver stiffness values were increased: 5.5 ± 1.4 kPa relative to normal participants. Liver stiffness directly correlated with liver biopsy-derived total fibrosis score, time since operation, mean Fontan pressure, γ-glutamyltransferase level, Model for End-Stage Liver Disease score, creatinine level, and pulmonary vascular resistance index. Liver stiffness was inversely correlated with cardiac index. All 3 participants with hepatic nodules exhibiting decreased contrast uptake on delayed postcontrast imaging and increased nodule stiffness had biopsy-proven hepatocellular carcinoma. CONCLUSION The association between hepatic stiffness and fibrosis scores, Model for End-Stage Liver Disease scores, and γ-glutamyltransferase level suggests that MRE may be useful in detecting (and possibly quantifying) hepatic cirrhosis in patients after the Fontan operation. The correlation between stiffness and post-Fontan time interval, mean Fontan pressure, pulmonary vascular resistance index, and reduced cardiac index suggests a role for long-term hepatic congestion in creating these hepatic abnormalities. Magnetic resonance elastography was useful in detecting abnormal nodules ultimately diagnosed as hepatocellular carcinoma. The relationship between stiffness with advanced fibrosis and hepatocellular carcinoma provides a strong argument for additional study and broader application of MRE in these patients.

Computed Tomography of Cardiac Pseudotumors and Neoplasms

Important features of cardiac masses can be clearly delineated on cardiac computed tomography (CT) imaging. This modality is useful in identifying the presence of a mass, its relationship with cardiac and extracardiac structures, and the features that distinguish one type of mass from another. A multimodality approach to the evaluation of cardiac tumors is advocated, with the use of echocardiography, CT imaging and magnetic resonance imaging as appropriately indicated. In this article, various cardiac masses are described, including pseudotumors and true cardiac neoplasms, and the CT imaging findings that may be useful in distinguishing these rare entities are presented.

Hypereosinophilic syndrome: cardiac diagnosis and management

Hypereosinophilic syndrome (HES) is a heterogeneous group of conditions that is defined at its core by hypereosinophilia (HE) (blood eosinophil count of >1.5×109/L) and organ damage directly attributable to the HE. Cardiac dysfunction occurs frequently in all forms of HES and is a major cause of morbidity and mortality. Once a significantly elevated eosinophil count is identified, it must be confirmed on repeat testing and the aetiology for the HE must be rigorously sought out with a focus on identifying whether organ dysfunction is occurring. Echocardiography is routinely performed to assess for cardiac involvement, looking for evidence of left ventricular and/or right ventricular apical obliteration or thrombi or a restrictive cardiomyopathy. Cardiac magnetic resonance imaging and CT are often useful adjuncts to establish the diagnosis but endomyocardial biopsy remains the gold standard. To decrease the degree of eosinophilia, treatment can include corticosteroids and/or imatinib based on the aetiology. Anticoagulation, standard heart failure therapy for a restrictive cardiomyopathy and finally cardiac transplantation may be indicated in the treatment algorithm.

Contraception Practices and Pregnancy Outcome in Patients after Fontan Operation

OBJECTIVE The feasibility and safety of pregnancy after the Fontan operation is not well understood. We sought to determine contraception practices and early and late outcomes of pregnancy after the Fontan operation. DESIGN We performed a retrospective review of medical records to identify women of childbearing age from the Mayo Clinic Fontan database. A follow-up questionnaire was mailed to all patients not known to be deceased at the time of study. Patients with available contraception and pregnancy data were included in the study. RESULTS Of the 138 women with available contraception data, 44% used no contraception, 12% each used barrier methods, combination hormone therapy or sterilization, 8% used Depo-Provera, 7% had intrauterine devices, 4% had a partner with a vasectomy and 1% used progestin pills. Six women had thrombotic complications (only one using oral contraceptives). Thirty-five women had pregnancy data available. Prior to the Fontan operation there were 10 pregnancies (8 miscarriages, 2 therapeutic abortions, and no live births). After the Fontan operation there were 70 pregnancies resulting in 35 miscarriages (50%), 29 live births (41%), and 6 therapeutic abortions (9%). There were no maternal deaths during pregnancy. During long-term follow up (26 ± 6 years since the Fontan), 1 death, and 1 cardiac transplant occurred. Mean gestational age of the newborns (n = 22/29) was 33.1 ± 4.0 weeks; mean birth weight (n = 20/29) was 2086 ± 770 g. There was 1 neonatal death because of prematurity and two children were born with congenital heart disease (one patent ductus arteriosus and one membranous ventricular septal defect). CONCLUSIONS Pregnancy after the Fontan operation is associated with a high rate of miscarriages, preterm delivery, and low birth weight. Further studies are needed to identify specific variables influencing risk stratification of pregnancy in this patient population.

Right Parasternal Lead Placement Increases Eligibility for Subcutaneous Implantable Cardioverter Defibrillator Therapy in Adults With Congenital Heart Disease.

BACKGROUND The subcutaneous implantable cardioverter defibrillator (S-ICD) provides an attractive option for patients with congenital heart disease (CHD) in whom a transvenous defibrillator is contraindicated. Given the unusual cardiac anatomy and repolarization strain, the surface electrocardiogram (ECG) is frequently abnormal, potentially increasing the screen failure rate. METHODSANDRESULTS We prospectively screened 100 adult CHD patients regardless of the presence of clinical indication for ICD utilizing a standard left sternal lead placement, as well as a right parasternal position. Baseline patient and 12-lead ECG characteristics were examined to assess for predictors of screen failure. Average patient age was 48±14 years, average QRS duration was 134±37 ms, and 13 patients were pacemaker dependent. Using the standard left parasternal electrode position, 21 patients failed screening. Of these 21 patients with screen failure, 9 passed screening with the use of right parasternal electrode positioning, reducing screening failure rate from 21% to 12%. QT interval and inverted T wave anywhere in V2-V6 leads were found to be independent predictors of left parasternal screening failure (P=0.01 and P=0.04, respectively). CONCLUSIONS Utilization of both left and right parasternal screening should be used in evaluation of CHD patients for S-ICD eligibility. ECG repolarization characteristics were also identified as novel predictors of screening failure in this group. (Circ J 2016; 80: 1328-1335).

When is the right time for Fontan conversion? The role of cardiopulmonary exercise test

BACKGROUND To determine if Fontan conversion (FC) resulted in improvement in exercise capacity (EC), and to determine the role of cardiopulmonary exercise test (CPET) in risk stratification of patients undergoing FC. METHODS A retrospective review of patients who underwent CPET prior to FC at Mayo Clinic from 1994 to 2014. The patients who also underwent post-operative CPET were selected for the analysis of improvement in EC defined as 10% increase in baseline peak oxygen consumption (VO2). RESULTS 75 patients CPET prior to FC; mean age 24±6years; 44 males (59%); and 51 (68%) were in NYHA III/IV prior to FC. Pre-operative peak VO2 was 15.5±3.4ml/kg/min. A comparison of pre- and post-FC CPET data was performed using 42 patients (56%) that underwent CPET after FC. Improvement in EC occurred in 18 of 42 patients (43%). Baseline peak VO2 >14ml/kg/min was associated with improved EC (hazard ratio [HR] 1.85; P=.02). Improvement in New York Heart Association (NYHA) class occurred in 12 (67%) patients with improved EC vs 2 (8%) without improved EC. Improvement in NYHA class was more likely to occur in patients with improved EC compared to those without improvement EC (odds ratio 4.11, P=.01). There were 10 (13%) perioperative deaths, and baseline peak VO2 ≤14ml/kg/min was predictive of perioperative mortality (HR 3.74; P<.001). CONCLUSIONS Baseline peak VO2 was predictive of perioperative survival, and improvement in EC. Performance on CPET in failing Fontan patients might be a useful clinical parameter in determining appropriate timing of FC.

Transthoracic Echocardiography versus Computed Tomography for Ascending Aortic Measurements in Patients with Bicuspid Aortic Valve

Background: Ascending aorta dilatation is common in bicuspid aortic valve (BAV). The aim of this study was to investigate agreement of transthoracic echocardiographic (TTE) measurement of the sinuses of Valsalva and the tubular mid–ascending aorta (Asc‐Ao) compared with electrocardiographically gated computed tomographic angiographic (CTA) assessment in patients with BAV. Methods: Fifty‐three patients with BAV (mean age, 54 ± 14 years; 74% men) who underwent both TTE and CTA imaging for ascending aortic assessment were retrospectively identified. All studies were measured de novo by experts. TTE measurements were obtained at the sinuses and the Asc‐Ao, at both systole and end‐diastole, using both leading edge–to–leading edge (L‐L) and inner edge–to–inner edge (I‐I) methods in the parasternal long‐axis (LAX) view. The sinuses were also measured in the parasternal short‐axis (SAX) view using the same methods plus mid‐diastole. CTA measurements were obtained in diastole using outer wall–to–outer wall (O‐O) and inner wall–to–inner wall (I‐I) methods. Correlation and agreement between the two imaging modalities were assessed using Lin correlation and Bland‐Altman analysis, respectively. Results: Compared with CTA O‐O maximum sinuses diameter, the best correlation and agreement were obtained using the TTE SAX mid‐diastolic L‐L method (&rgr; = 0.89, 2.6 ± 2.3 mm, respectively). Compared with CTA O‐O maximum Asc‐Ao diameter, the TTE LAX systolic L‐L method (&rgr; = 0.93, 1.3 ± 2.5 mm) was best. Compared with CTA I‐I maximum sinuses diameter, the TTE SAX mid‐diastole L‐L method (&rgr; = 0.95, 0.6 ± 2.2 mm) was unbiased. Compared with CTA I‐I maximum Asc‐Ao diameter, the TTE LAX end‐diastolic L‐L method (&rgr; = 0.95, 0.6 ± 2.4 mm) was unbiased. Conclusions: In patients with BAV aortopathy, unbiased agreement between CTA and TTE imaging can be obtained between the CTA I‐I method and TTE SAX mid‐diastolic L‐L method for the sinuses and the TTE LAX end‐diastolic L‐L method for the Asc‐Ao. When using the CTA O‐O method, the best agreement is obtained with the TTE SAX mid‐diastolic L‐L method for the sinuses (bias ˜2 mm) and the TTE LAX systolic L‐L method (bias ˜1 mm) for the Asc‐Ao. HighlightsIn patients with bicuspid aortic valve aortopathy, there is significant systematic underestimation of sinuses of Valsalva by the conventional TTE end‐diastolic L‐L method, as compared to ECG‐gated CTA.In patients with bicuspid aortic valve aortopathy, unbiased agreement between CTA and TTE imaging can be obtained between the CTA I‐I method and the TTE short‐axis mid‐diastolic L‐L method for the sinuses and the conventional TTE method for the Asc‐Ao.In patients with bicuspid aortic valve aortopathy, when using the CTA O‐O method, the best agreement is obtained with the TTE short‐axis mid‐diastolic L‐L method for the sinuses (bias ˜2 mm) and the conventional TTE method for the Asc‐Ao (bias ˜1 mm).

Aneurysms of the ascending aorta and arch: the role of imaging in diagnosis and surgical management

Thoracic aortic aneurysms tend to be asymptomatic and were previously often diagnosed only after a complication such as dissection or rupture occurred. Better imaging techniques and an increase in the use of cross-sectional imaging has led to an increase in the diagnosis of aortic aneurysms, which has allowed for elective treatment prior to the development of a complication. The location, size and etiology of an aneurysm all impact the clinical outcomes and these factors are used to determine the appropriate timing of surgical replacement. Surgeons often rely on the information obtained from preoperative imaging to determine when to intervene and what type of procedure will be necessary, making it important for the radiologist to understand these issues in order to provide the necessary information. Postoperative imaging after surgical replacement of the aorta is also important, as there are some common findings that occur in this patient population that can impact how they are treated. The purpose of this article is to review the etiology and associated findings of aneurysms of the ascending aorta and arch, with a focus on how computed tomography angiography and magnetic resonance angiography findings are used to determine the appropriate timing for elective replacement and the type of surgical procedure, as well as the role of follow-up imaging. This will include a review of the most commonly performed types of surgical procedures, to provide an understanding of how the findings of preoperative imaging studies impact what the surgeon does in the operating room, as well as the expected findings of postoperative imaging studies.

Adults With Congenital Heart Disease and Previous Intervention

Cardiac malformations occur in approximately 1% of live births. Advances in surgery, interventional cardiology, and medical care have translated into increasing numbers of adult patients with congenital heart disease. These patients, even after intervention, have cardiac sequelae that require specialized care by cardiologists and cardiac surgeons with expertise in the management of congenital cardiac disease. We review 8 of the most common lesions encountered after intervention in an adult congenital cardiac practice and discuss longitudinal follow-up, with a focus on appropriate testing, common hemodynamic and electrophysiological issues, and indications for reintervention.