Gisela C. Mueller

Müllerian Duct Anomalies: Comparison of MRI Diagnosis and Clinical Diagnosis

OBJECTIVE The objective of our study was to assess agreement between MRI and clinical diagnosis of müllerian duct anomalies and identify causes of discrepancy. MATERIALS AND METHODS Images of 103 patients who underwent MRI for suspected müllerian duct anomaly were reviewed. Imaging included axial T1-weighted spin-echo (SE) (TR/TE, 500/10) and sagittal, long-uterine-axis, and short-uterine-axis T2-weighted fast SE (5,000/80) sequences. Agreement between original MRI diagnosis and final clinical diagnosis was assessed using the kappa statistic. Two radiologists retrospectively reviewed all cases with inconsistent MRI and clinical diagnoses to identify causes of discrepancy. RESULTS There was excellent agreement (kappa = 0.8) between MRI and clinical diagnoses of müllerian duct anomalies. For evaluation of the uterus, there was agreement in 83 of 103 patients, disagreement in 15 of 103, and agreement could not be determined in five of 103 because of uncertain MRI diagnoses. The main causes of disagreement were MRI diagnosis of septate uteri with two cervices clinically diagnosed as didelphic, partial septate uteri clinically diagnosed as arcuate, and complex anomalies with features of more than one class. The main difficulties for MRI were the detection of small uteri or remnants, characterization of cervical dysgenesis and rare anomalies, overestimation of cervical mucosal folds, characterization of anomalies in the presence of fibroids, and delineation of vaginal abnormalities. CONCLUSION Despite excellent agreement between MRI and clinical diagnoses of müllerian duct anomalies, there are discrepancies and pitfalls resulting mostly from the absence of a precise and integrated classification scheme, unfamiliarity with rare and complex entities, and suboptimal depiction of some structures on MRI.

Magnetic Resonance Imaging for Identifying Patients With Cardiac Sarcoidosis and Preserved or Mildly Reduced Left Ventricular Function at Risk of Ventricular Arrhythmias

Background—The purpose of this study was to assess whether delayed enhancement (DE) on MRI is associated with ventricular tachycardia (VT)/ventricular fibrillation or death in patients with cardiac sarcoidosis and left ventricular ejection fraction >35%. Methods and Results—Fifty-one patients with cardiac sarcoidosis and left ventricular ejection fraction >35% underwent DE-MRI. DE was assessed by visual scoring and quantified with the full-width at half-maximum method. The patients were followed for 48.0±20.2 months. Twenty-two of 51 patients (63%) had DE. Forty patients had no prior history of VT (primary prevention cohort). Among those, 3 patients developed VT and 2 patients died. DE was associated with risk of VT/ventricular fibrillation or death (P=0.0032 for any DE and P<0.0001 for right ventricular DE). The positive predictive values of the presence of any DE, multifocal DE, and right ventricular DE for death or VT/ventricular fibrillation at mean follow-up of 48 months were 22%, 48%, and 100%, respectively. Among the 11 patients with a history of VT before the MRI, 10 patients had subsequent VTs, 1 of whom died. Conclusions—RV DE in patients with cardiac sarcoidosis is associated with a risk of adverse events in patients with cardiac sarcoidosis and preserved ejection fraction in the absence of a prior history of VT. Patients with DE and a prior history of VT have a high VT recurrence rate. Patients without DE on MRI have a low risk of VT.

Effect of ablation of frequent premature ventricular complexes on left ventricular function in patients with nonischemic cardiomyopathy

BACKGROUND Frequent idiopathic premature ventricular complexes (PVCs) can result in PVC-induced cardiomyopathy. Frequent PVCs can also aggravate ischemic cardiomyopathy. OBJECTIVE The purpose of this study was to investigate the impact of frequent PVCs on nonischemic cardiomyopathy. METHODS This was a consecutive series of 30 patients (mean age 59.1 ± 12.1; 18 men; mean ejection fraction [EF] 38% ± 15%) with structurally abnormal hearts based on the presence of scar on cardiac magnetic resonance imaging and/or a history of cardiomyopathy before the presence of frequent PVCs who were referred for ablation of frequent PVCs. RESULTS Ablation was successful in 18 of 30 patients (60%), resulting in an increase of mean EF from 33.9% ± 14.5% to 45.7% ± 17% (P < .0001) during mean follow-up of 30 ± 28 months. The PVC burden in these patients was reduced from 23.1% ± 8.8% to 1.0% ± 0.9% (P < .0001). Mean EF did not change in patients with a failed ablation procedure (44.4 ± 16 vs 43.5 ± 21, P = .85). The PVC site of origin was in scar tissue in 14 of 18 patients with a successful ablation procedure. Mean New York Heart Association functional class improved from 2.3 ± 0.6 to 1.1 ± 0.2 (P < .0001) in patients with a successful outcome and remained unchanged in patients with an unsuccessful outcome (1.9 ± 0.9 vs 1.9 ± 0.7, P = 1). CONCLUSION In patients with frequent PVCs and nonischemic cardiomyopathy, EF and functional class can be improved but not always normalized by successful PVC ablation. In most patients with an effective ablation, the arrhythmogenic substrate was located in scar tissue.

Cardiovascular MR imaging of conotruncal anomalies.

Conotruncal anomalies are congenital heart defects that result from abnormal formation and septation of the outflow tracts of the heart and great vessels. The major conotruncal anomalies include tetralogy of Fallot, transposition of the great arteries, double-outlet right ventricle, truncus arteriosus, and interrupted aortic arch. Cardiovascular magnetic resonance (MR) imaging is an important modality for the evaluation of patients with these defects. Major advances in cardiovascular MR imaging equipment and techniques allow precise delineation of the cardiovascular anatomy and accurate quantitative assessment of ventricular function and blood flow. The data provided by cardiovascular MR imaging are useful for treatment planning and posttreatment monitoring, supplement information obtained with echocardiography, and in many cases obviate cardiac catheterization.

Pilot Study of Cardiac Magnetic Resonance Imaging for Detection of Embolic Source After Ischemic Stroke

BACKGROUND Transesophageal echocardiography (TEE) is the standard for evaluating cardioembolic sources of stroke, although many strokes remain cryptogenic after TEE. Cardiac magnetic resonance (CMR) imaging may have advantages over TEE. We performed a prospective pilot study comparing CMR to TEE after stroke to assist in planning future definitive studies. METHODS Individuals with nonlacunar stroke within 90 days of undergoing clinical TEE were prospectively identified and underwent a 1.5 Tesla research CMR scan. Exclusion criteria included >50% relevant cervical vessel stenosis and inability to undergo nonsedated CMR. A descriptive comparison of cardioembolic source (intracardiac thrombus/mass, aortic atheroma ≥ 4 mm, or patent foramen ovale [PFO]) by study type was performed. RESULTS Twenty patients underwent CMR and TEE a median of 6 days apart. The median age was 51 years (interquartile range [IQR] 40, 63.5), 40% had hypertension, 15% had diabetes, 25% had a previous stroke/transient ischemic attack, 5% had atrial fibrillation, and none had coronary disease or heart failure. No patient had intracardiac thrombus or mass detected on either study. Aortic atheroma ≥ 4 mm thick was identified by TEE in 1 patient. CMR identified aortic atheroma as <4 mm in this patient (3 mm on CMR compared with 5 mm on TEE). PFO was identified in 6 of 20 patients on TEE; CMR found only 1 of these. CONCLUSIONS In this pilot study, TEE identified more potential cardioembolic sources than CMR imaging. Future studies comparing TEE and CMR after stroke should focus on older subjects at higher risk for cardiac disease to determine whether TEE, CMR, or both can best elucidate potential cardioembolic sources.

Congenital and Hereditary Causes of Sudden Cardiac Death in Young Adults: Diagnosis, Differential Diagnosis, and Risk Stratification

Sudden cardiac death is defined as death from unexpected circulatory arrest-usually a result of cardiac arrhythmia-that occurs within 1 hour of the onset of symptoms. Proper and timely identification of individuals at risk for sudden cardiac death and the diagnosis of its predisposing conditions are vital. A careful history and physical examination, in addition to electrocardiography and cardiac imaging, are essential to identify conditions associated with sudden cardiac death. Among young adults (18-35 years), sudden cardiac death most commonly results from a previously undiagnosed congenital or hereditary condition, such as coronary artery anomalies and inherited cardiomyopathies (eg, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy [ARVC], dilated cardiomyopathy, and noncompaction cardiomyopathy). Overall, the most common causes of sudden cardiac death in young adults are, in descending order of frequency, hypertrophic cardiomyopathy, coronary artery anomalies with an interarterial or intramural course, and ARVC. Often, sudden cardiac death is precipitated by ventricular tachycardia or fibrillation and may be prevented with an implantable cardioverter defibrillator (ICD). Risk stratification to determine the need for an ICD is challenging and involves imaging, particularly echocardiography and cardiac magnetic resonance (MR) imaging. Coronary artery anomalies, a diverse group of congenital disorders with a variable manifestation, may be depicted at coronary computed tomographic angiography or MR angiography. A thorough understanding of clinical risk stratification, imaging features, and complementary diagnostic tools for the evaluation of cardiac disorders that may lead to sudden cardiac death is essential to effectively use imaging to guide diagnosis and therapy.

Cardiovascular magnetic resonance imaging of hypoplastic left heart syndrome in children.

Cardiovascular magnetic resonance imaging (CMR) plays an important complementary role to echocardiography and conventional angiography in the evaluation of hypoplastic left heart syndrome. This imaging modality is particularly useful for assessing cardiovascular postsurgical changes, extracardiac vascular anatomy, ventricular and valvular function, and a variety of complications. The purpose of this article is to provide a contemporary review of the role of CMR in the management of untreated and surgically palliated hypoplastic left heart syndrome in children.

Thoracic Aorta (Multidetector Computed Tomography and Magnetic Resonance Evaluation)

Electrocardiographic gating, multidetector computed tomography (CT), dual-energy CT, parallel magnetic resonance imaging techniques, and advanced postprocessing methods are some of the many recent advancements that have revolutionized cross-sectional imaging of thoracic aorta. Imaging appearances of aortic disease can be complex and variable. Normal findings may simulate abnormalities, and many abnormalities may be asymptomatic. Knowledge and understanding of the imaging techniques, imaging findings of acute thoracic aortic syndromes, natural history of aortic diseases, and aortic surgical techniques may help to appropriately perform and interpret aorta-specific radiology studies.

Cardiomyopathy: Magnetic Resonance Imaging Evaluation

The term “cardiomyopathy” encompasses a broad and multi-etiologic spectrum of different entities, all of which are characterized by myocardial disease associated with cardiac dysfunction. The most commonly used classification system has been published in the 1995 World Health Organization/International Society and Federation of Cardiology task force report and classifies the cardiomyopathies according to the dominant functional impairment as follows 1 : ● Dilated cardiomyopathy ● Hypertrophic cardiomyopathy ● Restrictive cardiomyopathy ● Arrhythmogenic right ventricular cardiomyopathy ● Unclassified cardiomyopathies It is important to keep in mind that overlapping forms exist and that patients may present with features of more than one category. Cardiomyopathies may be idiopathic or associated with an underlying cardiac or systemic disorder, so-called “specific cardiomyopathies.” The term “specific cardiomyopathy” includes ischemic, valvular, hypertensive, inflammatory and metabolic cardiomyopathies, myocardial involvement by general systemic diseases, muscular dystrophies, neuromuscular disorders, sensitivity and toxic reactions, and peripartal cardiomyopathy. 1 The objective of this article was to provide a comprehensive overview of the role of cardiac magnetic resonance (MR) imaging in the evaluation of the major nonischemic cardiomyopathies.

MR Imaging of the Thoracic Aorta

Pre- and postoperative evaluation, serial follow-up studies, and screening examinations of the aorta are performed with noninvasive cross-sectional imaging modalities like CT and MR imaging. MR imaging allows for dedicated comprehensive evaluation without exposure to iodinated contrast or ionizing radiation. The additional advantage of MR imaging is that it can provide not only morphologic but also functional information. The purpose of this article is to advance knowledge and understanding of MR imaging techniques and their application to common aortic pathologies.