MRI for detection of anomalous pulmonary venous drainage in patients with sinus venosus atrial septal defects

The Sinus Venosus Veno-Venous Bridge: Not a septal defect

This review provides an update on the morphology of the sinus venosus defect. It was earlier believed that a 'common wall' separated the right pulmonary veins from the superior caval vein. In the sinus venosus defects, this wall was absent. Current evidence shows that the superior rim of the oval fossa, rather than forming a second septum or representing a common wall, is an infolding between the walls of the caval veins and the right pulmonary veins. The sinus venosus defect is caused by the anomalous connection of one or more pulmonary veins to a systemic vein. However, the pulmonary vein(s) retain their left atrial connections, leading to a veno-venous bridge that allows interatrial shunting outside the oval fossa. True atrial septal defects are located within the oval fossa or in the anteo-inferior buttress, while sinus venosus defects, ostium defects and coronary sinus defects are morphologically distinct from them.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the use of cardiovascular magnetic resonance in pediatric congenital and acquired heart disease : Endorsed by The American Heart Association

Cardiovascular magnetic resonance (CMR) has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of CMR in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of CMR in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the Use of Cardiac Magnetic Resonance in Pediatric Congenital and Acquired Heart Disease: Endorsed by The American Heart Association

Cardiovascular magnetic resonance has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of cardiovascular magnetic resonance in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of cardiovascular magnetic resonance in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Right/Left Ventricular Blood Pool T2 Ratio as an Innovative Cardiac MRI Screening Tool for the Identification of Left-to-Right Shunts in Patients With Right Ventricular Disease

BACKGROUND

Left-to-right (L-R) shunts are characterized by a pathological connection between high- and low-pressure systems, leading to a mixing of oxygen-rich blood with low oxygenated blood. They are typically diagnosed by phase-contrast cardiac magnetic resonance imaging (MRI) which requires extensive planning. T2 is sensitive to blood oxygenation and may be able to detect oxygenation differences between the left (LV) and right ventricles (RV) caused by L-R shunts.

PURPOSE

To test the feasibility of routine T2 mapping to detect L-R shunts.

STUDY TYPE

Retrospective.

POPULATION

Patients with known L-R shunts (N = 27), patients with RV disease without L-R shunts (N = 21), and healthy volunteers (HV; N = 52).

FIELD STRENGTH/SEQUENCE

1.5 and 3 T/balanced steady-state free-precession (bSSFP) sequence (cine imaging), T2-prepared bSSFP sequence (T2 mapping), and velocity sensitized gradient echo sequence (phase-contrast MRI).

ASSESSMENT

Aortic (Qs) and pulmonary (Qp) flow was measured by phase-contrast imaging, and the Qp/Qs ratio was calculated as a measure of shunt severity. T2 maps were used to measure T2 in the RV and LV and the RV/LV T2 ratio was calculated. Cine imaging was used to calculate RV end-diastolic volume index (RV-EDVi).

STATISTICAL TESTS

Wilcoxon test, paired t-tests, Spearmen correlation coefficient, receiver operating curve (ROC) analysis. Significance level P < 0.05.

RESULTS

The Qp/Qs and T2 ratios in L-R shunt patients (1.84 ± 0.84 and 0.89 ± 0.07) were significantly higher compared to those in patients with RV disease (1.01 ± 0.03 and 0.72 ± 0.10) and in HV (1.04 ± 0.04 and 0.71 ± 0.09). A T2 ratio of >0.78 showed a sensitivity, specificity, and negative predictive value of 100%, 73.9%, and 100%, respectively, for the detection of L-R shunts. The T2 ratio was strongly correlated with the severity of the shunt (r = 0.83).

DATA CONCLUSION

RV/LV T2 ratio is an imaging biomarker that may be able to detect or rule-out L-R shunts. Such a diagnostic tool may prevent unnecessary phase-contrast acquisitions in cases with RV dilatation of unknown etiology.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Cardiovascular Magnetic Resonance in Congenital Heart Disease: Focus on Heart Failure

Over the past decade, cardiovascular magnetic resonance (CMR) has become a mainstream noninvasive imaging tool for assessment of adult and pediatric patients with congenital heart disease. It provides comprehensive anatomic and hemodynamic information that echocardiography and catheterization alone do not provide. Extracardiac anatomy can be delineated with high spatial resolution, intracardiac anatomy can be imaged in multiple planes, and functional assessment can be made accurately and with high reproducibility. In patients with heart failure, CMR provides not only reference standard evaluation of ventricular volumes and function but also information about the possible causes of dysfunction.

SCMR Position Paper (2020) on clinical indications for cardiovascular magnetic resonance

The Society for Cardiovascular Magnetic Resonance (SCMR) last published its comprehensive expert panel report of clinical indications for CMR in 2004. This new Consensus Panel report brings those indications up to date for 2020 and includes the very substantial increase in scanning techniques, clinical applicability and adoption of CMR worldwide. We have used a nearly identical grading system for indications as in 2004 to ensure comparability with the previous report but have added the presence of randomized controlled trials as evidence for level 1 indications. In addition to the text, tables of the consensus indication levels are included for rapid assimilation and illustrative figures of some key techniques are provided.

Septum primum malposition defect and inferior sinus venosus defect: a rare association

We present a case of a 2-year-old girl who presented with respiratory distress and umbilical abscess, and was found to have an inferior sinus venosus defect, malposition of the atrial septum primum, absent septum secundum, and anomalous drainage of the right upper and lower pulmonary veins to the right atrium.

Sinus venosus atrial septal defect as a cause of palpitations and dyspnea in an adult: a diagnostic imaging challenge

Sinus venosus atrial septal defects (SV-ASD) have nonspecific clinical presentations and represent a diagnostic imaging challenge. Transthoracic echocardiography (TTE) remains the initial diagnostic imaging modality. However, detection rates have been as low as 12%. Transesophageal echocardiography (TEE) improves diagnostic accuracy though it may not detect commonly associated partial anomalous pulmonary venous return (PAPVR). Cardiac magnetic resonance (CMR) imaging provides a noninvasive, highly sensitive and specific imaging modality of SV-ASD. We describe a case of an adult male with exercise-induced, paroxysmal supraventricular tachycardia who presented with palpitations and dyspnea. Despite nondiagnostic imaging results on TTE, CMR proved to be instrumental in visualizing a hemodynamically significant SV-ASD with PAPVR that ultimately led to surgical correction.

The role of cardiac MRI in the diagnosis and management of sinus venosus atrial septal defect

Sinus venosus atrial septal defects (SV-ASDs) are inter-atrial communications caused by a deficiency of the common wall between the superior or inferior vena cava and the right-sided pulmonary veins. The diagnosis can be challenging, especially in adults with delayed presentation. We present images that illustrate an example of the role of cardiac magnetic resonance imaging (CMRI) in the diagnosis and follow-up of a patient with SV-ASD.

Missed case of sinus venosus atrial septal defect post coronary artery bypass grafting

We report a case of a 41-year-old Indian man who initially underwent an emergency coronary artery bypass grafting surgery (CABG) after presenting with an anterolateral myocardial infarction.

Post-operatively he developed progressively worsening symptoms of right heart failure with increasing abdominal distension and lower limb swelling. Clinically, the patient was in NYHA class 4 heart failure.

He was admitted multiple times for the treatment of his heart failure, which was recalcitrant to diuretic therapy.

He subsequently underwent an MRI scan, which revealed near transmural myocardial infarction involving mainly the left side of the heart. The right atrium and ventricle were grossly dilated, with moderate to severe right ventricular systolic dysfunction. A sinus venosus atrial septal defect with right-sided partial anomalous pulmonary venous drainange (PAPVD) was noted. He subsequently underwent surgery to repair the sinus venosus atrial septal defect (ASD) as well as re-route the PAPVD to the left atrium (LA). He was discharged on post-operative day 19 with oral diuretics.

On follow-up at 1 month, the patient's symptoms had resolved and his clinical status corresponded to NYHA class 1–2.

Multimodality imaging of anomalous pulmonary veins

Partial anomalous pulmonary venous connection (PAPVC) is an extremely rare congenital condition where one or more of the pulmonary veins are connected to the venous circulation. Although initially suspected with unexplained right ventricular enlargement on transthoracic echocardiography (TTE), cardiac MRI is able to delineate the anatomical variant. We present a case of a 65-year-old male diagnosed with left sided PAPVC using multimodality cardiac imaging.

[MRI for therapy planning in patients with atrial septum defects]

PURPOSE

The aim of this study was to determine the value of a combined magnetic resonance imaging (MRI) protocol including steady-state free precession (SSFP) imaging, phase-contrast measurements and contrast-enhanced MR angiography (CE-MRA) for presurgical or preinterventional diagnostic imaging in patients with suspected atrial septum defects.

MATERIAL AND METHODS

Out of 65 MRI studies of patients with suspected atrial septum defects, 56 patients were included in the study. The atrial septum defects were identified on cine images. Velocity encoded flow measurements were used to determine shunt volumes, which were compared with invasive oxymetry in 24 patients. Contrast-enhanced MRI was used to assess the thoracic vessels in order to detect vascular anomalies. The findings were compared with the intraoperative results.

RESULTS

A total of 24 patients with high shunt volumes were treated either surgically (16 patients) or interventionally (8 patients) and 32 patients with low shunt volumes did not require surgical or interventional treatment. The vascular anomaly, which in all cases was anomalous pulmonary venous return, was confirmed by the intraoperative findings. The type and location of atrial septal defects which required treatment, were confirmed intraoperatively or during the intervention. The results of shunt quantification by MRI showed a good correlation with the results of invasive oximetry (r=0.91, p <0.0001).

CONCLUSION

A combined MRI protocol including cine SSFP images, velocity-encoded flow measurements and CE-MRA is an accurate method for preoperative and preinterventional evaluation of atrial septum defects.