Magnetic resonance imaging is the diagnostic tool of choice in the preoperative evaluation of patients with partial anomalous pulmonary venous return

Importance of Cardiovascular Magnetic Resonance Applied to Congenital Heart Diseases in Pediatric Age: A Narrative Review

Congenital heart diseases (CHDs) represent a heterogeneous group of congenital defects, with high prevalence worldwide. Non-invasive imaging is essential to guide medical and surgical planning, to follow the patient over time in the evolution of the disease, and to reveal potential complications of the chosen treatment. The application of cardiac magnetic resonance imaging (CMRI) in this population allows for obtaining detailed information on the defects without the necessity of ionizing radiations. This review emphasizes the central role of CMR in the overall assessment of CHDs, considering also the limitations and challenges of this imaging technique. CMR, with the application of two-dimensional (2D) and tri-dimensional (3D) steady-state free precession (SSFP), permits the obtaining of very detailed and accurate images about the cardiac anatomy, global function, and volumes' chambers, giving essential information in the intervention planning and optimal awareness of the postoperative anatomy. Nevertheless, CMR supplies tissue characterization, identifying the presence of fat, fibrosis, or oedema in the myocardial tissue. Using a contrast agent for angiography sequences or 2D/four-dimensional (4D) flows offers information about the vascular, valvular blood flow, and, in general, the cardiovascular system hemodynamics. Furthermore, 3D SSFP CMR acquisitions allow the identification of coronary artery abnormalities as an alternative to invasive angiography and cardiovascular computed tomography (CCT). However, CMR requires expertise in CHDs, and it can be contraindicated in patients with non-conditional devices. Furthermore, its relatively longer acquisition time and the necessity of breath-holding may limit its use, particularly in children under eight years old, sometimes requiring anesthesia. The purpose of this review is to elucidate the application of CMR during the pediatric age.

Long-Term Outcomes of Unrepaired Isolated Partial Anomalous Pulmonary Venous Connection With an Intact Atrial Septum

The natural history of an unrepaired isolated partial anomalous pulmonary venous connection(s) (PAPVC) and the absence of other congenital anomalies remains unclear. This study aimed to expand the understanding of the clinical outcomes in this population. Isolated PAPVC with an intact atrial septum is a relatively uncommon condition. There is the perception that patients with isolated PAPVC are usually asymptomatic, that the lesion generally has a limited hemodynamic impact, and that surgical repair is rarely justified. For this retrospective study, we reviewed our institutional database to identify patients with either 1 or 2 anomalous pulmonary veins that drain a portion of but not the complete ipsilateral lung. Patients with previous surgical cardiac repair, coexistence of other congenital cardiac anomalies that would result in either pretricuspid or post-tricuspid loading of the right ventricle (RV), or scimitar syndrome were excluded. We reviewed their clinical course over the follow-up period. We identified 53 patients; 41 with a single and 12 with 2 anomalous PAPVC. A total of 30 patients (57%) were men, with a mean age at the latest clinic visit of 47 ± 19 years (18 to 84 years). Turner syndrome (6 of 53, 11.3%), bicuspid aortic valve (6 of 53, 11.3%), and coarctation of the aorta (5 of 53, 9.4%) were commonly associated anomalies. A single anomalous left upper lobe vein was the most commonly identified variation. More than half of the patients were asymptomatic. Cardiopulmonary exercise test demonstrated a maximal oxygen consumption of 73 ± 20% expected (36 to 120). Transthoracic echocardiography demonstrated a mean RV basal diameter of 4.4 ± 0.8 cm, RV systolic pressure of 38 ± 13 (16 to 84) mm Hg. A total of 8 patients (14.8%) had ≥moderate tricuspid regurgitation. Cardiac magnetic resonance in 42 patients demonstrated a mean RV end-diastolic volume index of 122 ±3 0 ml/m² (66 to 188 ml/m²), of which in 8 (14.8%), it was >150 ml/m². Magnetic resonance imaging-based Qp:Qs was 1.6 ± 0.3. A total of 5 patients (9.3%) had established pulmonary hypertension (mean pulmonary artery pressure ≥25 mm Hg). In conclusion, isolated single or dual anomalous pulmonary venous connection is not necessarily a benign congenital anomaly because a proportion of patients develop pulmonary hypertension and/or RV dilation. Regular follow-up and on-going patient surveillance with cardiac imaging is advised.

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.

Clinical Significance of Partial Anomalous Pulmonary Venous Connections (Isolated and Atrial Septal Defect Associated) Determined by Cardiovascular Magnetic Resonance

BACKGROUND

Partial anomalous venous connections (PAPVC) are associated with left to right shunting and right heart dilatation. Identification of PAPVC has increased with widespread use of cross-sectional imaging modalities. However, management strategies are mostly based on expert opinion given the scarcity of data from large series. We aimed to define types and significance of isolated and atrial septal defect (ASD) associated PAPVC detected by cardiovascular magnetic resonance.

METHODS

We retrospectively reviewed our cardiovascular magnetic resonance database from 2002 to 2018 to identify isolated or ASD-associated PAPVC cases.

RESULTS

A total of 215 patients (median age 46 years; range, 6-83) with isolated or ASD-associated PAPVC were identified among 102 135 clinical cardiovascular magnetic resonance studies. Of these, 104 were isolated and 111 were associated with an ASD. Anomalous connection of right upper pulmonary vein was the most common single venous anomaly (99/215), but in the isolated PAPVC group there were more anomalous left than right upper pulmonary veins (39 versus 34). The Qp/Qs was significantly higher for isolated anomalous single right upper pulmonary vein than left upper pulmonary vein (1.6 versus 1.4 respectively; P=0.01) as were right ventricular end-diastolic volumes (113.7±30.9 versus 90 [57-157] mL/m2, P=0.004). In the PAPVC with an ASD group, sinus venosus ASDs (82%) were associated with right-sided PAPVCs while both right and left-sided venous anomalies were seen in secundum ASDs (18%). In a substantial number of patients (30 out of 91) with sinus venosus ASDs, PAPVCs were more complex and involved more than a single anomalous right upper pulmonary vein; and in 5 patients with ASD, PAPVC was identified only after the ASD closure.

CONCLUSIONS

This large series provides descriptive and hemodynamic features for isolated and ASD-associated PAPVCs. Anomalous isolated right upper pulmonary vein may cause a significant shunt (Qp/Qs >1.5). PAPVC associated with sinus venosus and secundum ASDs might be more complex than a single anomalous pulmonary vein and missed before ASD correction.

Imaging the adult with simple shunt lesions: position paper from the EACVI and the ESC WG on ACHD. Endorsed by AEPC (Association for European Paediatric and Congenital Cardiology)

In 2018, the position paper 'Imaging the adult with congenital heart disease: a multimodality imaging approach' was published. The paper highlights, in the first part, the different imaging modalities applied in adult congenital heart disease patients. In the second part, these modalities are discussed more detailed for moderate to complex anatomical defects. Because of the length of the paper, simple lesions were not touched on. However, imaging modalities to use for simple shunt lesions are still poorly known. One is looking for structured recommendations on which they can rely when dealing with an (undiscovered) shunt lesion. This information is lacking for the initial diagnostic process, during repair and at follow-up. Therefore, this paper will focus on atrial septal defect, ventricular septal defect, and persistent arterial duct. Pre-, intra-, and post-procedural imaging techniques will be systematically discussed. This position paper will offer algorithms that might help at a glance. The document is prepared for general cardiologists, trainees, medical students, imagers/technicians to select the most appropriate imaging modality and to detect the requested information for each specific lesion. It might serve as reference to which researchers could refer when setting up a (imaging) study.

Surgical treatment of partial anomalous pulmonary venous connection misdiagnosed as atrial septal defect underwent transcatheter occlusion: A case report

This case highlights the importance of coordinating with cardiopediatricians or congenitalists in the evaluation and treatment of ASD.

Multi-Modality Imaging Approach in a Challenging Case of Surgically Corrected Partial Anomalous Pulmonary Venous Return and Atrial Tachycardia Treated With Radiofrequency Ablation

Pulmonary anomalous venous return (PAPVR) is defined as a congenital anomaly in which at least one but not all of the pulmonary veins abnormally drain into a systemic vein or directly into the right atrium. Signs and symptoms related to this condition are due to the hemodynamic abnormalities secondary to left-to-right shunt and the possible presence of other associated cardiac anomalies (e.g., sinus venous atrial septal defect). Therefore, depending on the extent of the shunt, the clinical presentation of PAPVR is variable, ranging from asymptomatic patients to patients affected by severe heart failure with right-sided volume overload. PAPVR with a clinically significant shunt should be referred for surgical correction with different techniques depending on the presence of associated cardiac anomalies.

We are presenting a case of partial anomalous venous return (PAPVR) in a 66-year-old man who underwent surgery 26 years ago to correct an anomalous venous connection between the right superior pulmonary vein (RSPV) and the superior vena cava (SVC) through a veno-atrial baffle. The patient was admitted to the emergency department due to atrial tachycardia. Trans-thoracic echocardiography (TTE) showed a dilated right ventricle (RV) with mild RV systolic dysfunction and pulmonary hypertension. Cardiac magnetic resonance (CMR) further confirmed the findings described by TTE and also demonstrated areas of fibrosis replacement in the hinge points. Cardiac computed tomography (CCT) was able to accurately depict and evaluate the surgically created veno-atrial baffle and also showed an anomalous connection between the left superior pulmonary vein (LSPV) and the brachiocephalic vein (BCV) through a vertical vein. The patient was successfully treated with radiofrequency ablation for his arrhythmia.

Quantification of pulmonary/systemic shunt ratio by single-acquisition phase-contrast cardiovascular magnetic resonance

PURPOSE

Phase-contrast cardiovascular magnetic resonance (PC-CMR) quantification of intracardiac shunt (measuring the pulmonary to systemic flow ratio, Qp/Qs) is typically determined by measuring flow through planes perpendicular the pulmonary trunk (PA) and ascending aorta (Ao). This method is subject to error from presence of background velocity offsets and requires two scan acquisitions. We evaluated an alternate PC-CMR technique for quantifying Qp/Qs using a single modified plane that encompasses both the PA and Ao.

MATERIAL AND METHODS

In 53 patients evaluated for intracardiac shunting, PC-CMR measurement in the individual Ao and PA planes and also in a single-acquisition plane was obtained and Qp/Qs calculated by each method. Bland-Altman analysis was performed to evaluate the agreement between the two methods.

RESULTS

The 95% confidence limits of agreement ranged from -0.52 to +0.34 indicating good agreement between the two methods. There was excellent agreement on the clinically relevant threshold value of Qp/Qs ratio of 1.5 (representing criteria for surgical correction of shunt).

CONCLUSIONS

Qp/Qs determined from the single-acquisition approach agrees well with that of the individual PA and Ao method and offers potential improved accuracy (due to background velocity offset).

Pediatric Cardiac MR Imaging:: Practical Preoperative Assessment

Prevalence of patients with congenital heart disease (CHD) is rapidly increasing due to continuous advancements in diagnostic techniques and medical or surgical treatment approaches. Along with cardiac computed tomography angiography, cardiac magnetic resonance (CMR) serves as a fundamental imaging modality for pre-surgical planning in patients with CHD, as CMR allows for the evaluation of cardiac and great vessel anatomy, biventricular function, flow dynamics, and tissue characterization. This information is essential for risk-assessment and optimal timing of surgical interventions. This article discusses the current role of pediatric cardiac MR imaging as a practical preoperative assessment tool in the pediatric population.

How many versus how much: comprehensive haemodynamic evaluation of partial anomalous pulmonary venous connection by cardiac MRI

OBJECTIVES

The objective of this study was to investigate the effect of location and number of anomalously connected pulmonary veins and any associated atrial septal defect (ASD) on the magnitude of left-to-right shunting in patients with partial anomalous pulmonary venous connection (PAPVC), and how that influences right ventricular volume loading.

METHODS AND RESULTS

The cardiac magnetic resonance (CMR) and echocardiography examinations of 26 paediatric patients (mean age, 11.2 ± 5.1 years) with unrepaired PAPVC were analysed. Fourteen patients had right-sided, 11 left-sided and 1 patient bilateral PAPVC. An ASD was present in 11 patients, of which none had a Qp/Qs < 1.5 and 8 had a Qp/Qs≥ 2.0. No patient with isolated left upper PAPVC experienced a Qp/Qs ≥ 2.0 compared to 9/12 patients with right upper PAPVC. Qp/Qs correlated with indexed right ventricle (RV) end-diastolic volume (RVEDVi, r = 0.59, p = 0.002) by CMR and with echocardiographic right ventricular end-diastolic dimension (RVED) z-score (r = 0.68, p = 0.003). A RVEDVi >124 ml/m² by CMR and a RVED z-score >2.2 by echocardiography identified patients with a Qp/Qs ≥1.5 with good sensitivity and specificity.

CONCLUSIONS

An asymptomatic patient with a single anomalously connected left upper pulmonary vein and without an ASD is unlikely to have a significant left-to-right shunt. On the other hand, right-sided PAPVC is frequently associated with a significant left-to-right shunt, especially when an ASD is present.

KEY POINTS

• Patients with PAPVC and ASD routinely have a significant left-to-right shunt. • Patients with right PAPVC are likely to have a significant left-to-right shunt. • Patients with left PAPVC are unlikely to have a significant left-to-right shunt. • CMR is helpful in decision-making for patients with PAPVC.

Deciphering a case of pulmonary hypertension in a young female: Partial anomalous pulmonary venous drainage the culprit

Partial anomalous pulmonary venous drainage (PAPVD) is a rare congenital cardiac defect and is associated with sinus venosus atrial septal defect. While most cases are asymptomatic, a patient can present with pulmonary hypertension (PHTN) and it can be difficult to diagnose. Here, we discuss the case of a young female with PHTN who was found to have two right-sided PAPVD. Through this case, authors try to emphasize the importance of meticulous and thorough investigation when evaluating PHTN, which allows for correct diagnosis and a timely intervention before PHTN becomes irreversible.

Low-Dose Computed Tomographic Imaging of Partial Anomalous Pulmonary Venous Connection in Children

Background:

In this study, we aimed to determine lobar distribution, drainage sites, and associated cardiovascular anomalies of partial anomalous pulmonary venous connection in pediatric patients using low-dose multidetector computed tomographic angiography.

Methods:

Sixty-one cases (27 female, mean age: 4.7 years) with partial anomalous pulmonary venous connection diagnosed by multidetector computed tomographic angiography were included in this study. In all patients, multidetector computed tomographic angiography examinations were performed using dual-source 256-slice scanner without sedation.

Results:

In 61 patients, 73 anomalous pulmonary veins were detected, 56 (77%) of them were right-sided and 17 (23%) were left-sided. Of 56 right-sided anomalous pulmonary veins in 49 patients, 38 (68%) drained into superior vena cava, eight (14%) into atriocaval junction, six (11%) into inferior vena cava, three (5%) into right atrium, and one (2%) into levoatriocardinal vein. Of 17 left-sided anomalous pulmonary veins in 12 patients, 16 (94%) drained into left innominate vein, and one (6%) into coronary sinus. Only seven (12%) patients had isolated partial anomalous pulmonary venous connection, whereas 54 (88%) patients had additional cardiovascular anomalies. The most common (66%) associated anomaly is atrial septal defect. The overall mean effective radiation dose was 1.12 mSv (range: 0.15-7.41 mSv), and it was 0.58 mSv (range: 0.15-0.73) in the patients younger than one-year old.

Conclusions:

The presence and course of the anomalous pulmonary veins and associated cardiovascular anomalies can be reliably detected by dual-source 256-slice multidetector computed tomographic angiography with low radiation doses.

Total Anomalous Pulmonary Venous Connection in Children: Preoperative Evaluation with Low-Dose Multidetector Computed Tomographic Angiography

We report the results of our retrospective evaluation, from February 2011 through August 2014, of the anatomic features of total anomalous pulmonary venous connection (TAPVC) and its associated cardiovascular anomalies in a pediatric population. In all 43 patients under study (23 female; average age, 9 mo [range, 4 d-7.1 yr]), these examinations had been performed with a dual-source 256-detector scanner. The type of TAPVC, the presence of obstruction, and the association with other cardiovascular anomalies were investigated and recorded. In accordance with the absence or presence of these accompanying anomalies, patients were subdivided into 2 groups: isolated and complex. In the 43 patients, 22 (51%) TAPVCs were supracardiac, 10 (23%) were cardiac, 6 (14%) were infracardiac, and 5 (12%) were mixed. Obstruction was detected in 7 patients. Seventeen patients were in the isolated group and 26 in the complex group. The diagnostic agreements between multidetector computed tomographic angiographic and surgical results were 100% in both the isolated and complex groups. The overall average effective radiation dose was 0.66 mSv (range, 0.15-1.11 mSv); and it was 0.52 mSv (range, 0.12-0.72 mSv) in patients younger than 1 year of age. We conclude that computed tomographic angiography with a dual-source 256-slice multidetector scanner is a reliable imaging method that enables, despite lower radiation doses, the detailed and comprehensive anatomic imaging of TAPVC in neonates and children.

Improved quantification and mapping of anomalous pulmonary venous flow with four-dimensional phase-contrast MRI and interactive streamline rendering

BACKGROUND

Cardiac MRI is routinely performed for quantification of shunt flow in patients with anomalous pulmonary veins, but can be technically-challenging to perform. Four-dimensional phase-contrast (4D-PC) MRI has potential to simplify this exam. We sought to determine whether 4D-PC may be a viable clinical alternative to conventional 2D phase-contrast MR imaging.

METHODS

With institutional review board approval and HIPAA-compliance, we retrospectively identified all patients with anomalous pulmonary veins who underwent cardiac MRI at either 1.5 Tesla (T) or 3T with parallel-imaging compressed-sensing (PI-CS) 4D-PC between April, 2011 and October, 2013. A total of 15 exams were included (10 male, 5 female). Algorithms for interactive streamline visualization were developed and integrated into in-house software. Blood flow was measured at the valves, pulmonary arteries and veins, cavae, and any associated shunts. Pulmonary veins were mapped to their receiving atrial chamber with streamlines. The intraobserver, interobserver, internal consistency of flow measurements, and consistency with conventional MRI were then evaluated with Pearson correlation and Bland-Altman analysis.

RESULTS

Triplicate measurements of blood flow from 4D-PC were highly consistent, particularly at the aortic and pulmonary valves (cv 2-3%). Flow measurements were reproducible by a second observer (ρ = 0.986-0.999). Direct measurements of shunt volume from anomalous veins and intracardiac shunts matched indirect estimates from the outflow valves (ρ = 0.966). Measurements of shunt fraction using 4D-PC using any approach were more consistent with ventricular volumetric displacements than conventional 2D-PC (ρ = 0.972-0.991 versus 0.929).

CONCLUSION

Shunt flow may be reliably quantified with 4D-PC MRI, either indirectly or with detailed delineation of flow from multiple shunts. The 4D-PC may be a more accurate alternative to conventional MRI.

Cardiovascular magnetic resonance phase contrast imaging

Cardiovascular magnetic resonance (CMR) phase contrast imaging has undergone a wide range of changes with the development and availability of improved calibration procedures, visualization tools, and analysis methods. This article provides a comprehensive review of the current state-of-the-art in CMR phase contrast imaging methodology, clinical applications including summaries of past clinical performance, and emerging research and clinical applications that utilize today's latest technology.

What radiologists need to know about the pulmonary-systemic flow ratio (Qp/Qs): what it is, how to calculate it, and what it is for

Cardiac magnetic resonance imaging (cMRI) provides abundant morphological and functional information in the study of congenital heart disease. The functional information includes pulmonary output and systemic output; the ratio between these two (Qp/Qs) is the shunt fraction. After birth, in normal conditions the pulmonary output is practically identical to the systemic output, so Qp/Qs = 1. In patients with « shunts » between the systemic and pulmonary circulations, the ratio changes, and the interpretation of these findings varies in function of the location of the shunt (intracardiac or extracardiac) and of the associated structural or postsurgical changes. We review the concept of Qp/Qs; the methods to calculate it, with special emphasis on cMRI; and the meaning of the results obtained. We place special emphasis on the relevance of these findings depending on the underlying disease and the treatment the patient has undergone.

[Anomalous pulmonary venous return in a pregnant woman identified by cardiac magnetic resonance]

Anomalous pulmonary venous return (APVR) is a rare cardiac anomaly defined as one or more pulmonary veins draining into a structure other than the left atrium, with venous return directly or indirectly to the right atrium. The most common form is partial APVR, in which one to three pulmonary veins drain into systemic veins or into the right atrium. We report the case of a woman diagnosed with partial APVR by magnetic resonance imaging during pregnancy.

An unusual cause of respiratory distress in an infant

Partial anomalous venous connection (PAPVC) is a congenital cardiovascular defect where one or more (but not all) of the pulmonary veins return anomalously back to the right atrium, either via a direct or indirect connection. It often occurs with other cardiac defects, most commonly a secundum atrial septal defect. Individuals with a large degree of shunting will present with dyspnea, fatigue, and, in some cases, heart failure. Clinical associations and variants of PAPVC include scimitar syndrome, pseudo-scimitar or meandering right pulmonary vein, sinous venosus defects, malposition of the septum primum, and Turner syndrome. The patient in this case, a previously healthy, 6-month-old, full-term male, presented to the emergency department for evaluation of respiratory distress and wheezing. The infant was first seen in his pediatrician's office, where he was noted to be tachypneic and wheezing. He was feeding without difficulty, voiding well, and was active and playful. The patient had passed critical congenital heart disease screening after his birth and prior to discharge, and the family history was negative for any respiratory or cardiac conditions. Cardiac magnetic resonance imaging is becoming the mode of choice for diagnosis of PAPVC. The definitive treatment is surgical correction, but surgery is not indicated in all cases, especially if the patient is asymptomatic and the degree of shunting is small. Patients with isolated PAPVC who undergo surgical correction have good long-term outcomes. In this case, the patient underwent the Warden procedure, which causes an increased risk of superior vena cava stenosis or obstruction to the right atrium. This patient will require lifelong follow-up to assess for new onset pulmonary venous obstruction.

Partial anomalous pulmonary venous connection and pulmonary arterial hypertension

BACKGROUND AND OBJECTIVE

Isolated partial anomalous pulmonary venous connection (PAPVC) has been implicated as a cause of pulmonary arterial hypertension (PAH); however this condition is often overlooked in the diagnostic work up of patients with PH. We studied the prevalence of PAH both in patients with isolated PAPVC or associated with other congenital heart diseases (CHD) such as atrial septal defect (ASD). We also aimed to identify factors related to the presence of PAH in these patients.

METHODS

We retrospectively analyzed data from the Adult CHD database at the Cleveland Clinic, U.S.A. between October 2005-2010. We included all patients diagnosed with PAPVC with or without other CHD. We excluded all patients with previous corrective surgeries.

RESULTS

We identified 14 (2.5%) patients with PAPVC. Group I included patients with PAPVC (with or without patent foramen ovale (PFO)). Group II included patients with PAPVC associated with other CHD. PAH was seen in six (6/14, 42.8%) patients, two (2/7, 28.5%) in group I and four (4/7, 57.1%) in group II (P = 0.3). The mean pulmonary artery pressure in all patients (n = 14) was 29.5 ± 13.8 mm Hg. group I had a mean PAP of 23.6 ± 6.6 mm Hg as compared to 33.7 ± 16.5 mm Hg for group II (P = 0.34). The two patients in group I with PAH had either two anomalous pulmonary veins or a condition (sickle cell disease) that could potentially explain the haemodynamic findings.

CONCLUSIONS

Patients with PAPVC (with or without PFO) in the absence of other CHD had normal pulmonary arterial pressure (PAP) unless they have two pulmonary veins with anomalous return or associated conditions known to cause PAH.

[Clinical indications for the use of cardiac MRI. By the SIRM Study Group on Cardiac Imaging]

Cardiac magnetic resonance (CMR) is considered an useful method in the evaluation of many cardiac disorders. Based on our experience and available literature, we wrote a document as a guiding tool in the clinical use of CMR. Synthetically we describe different cardiac disorders and express for each one a classification, I to IV, depending on the significance of diagnostic information expected.

A prospective audit of safety issues associated with general anesthesia for pediatric cardiac magnetic resonance imaging

BACKGROUND/OBJECTIVES

Cardiac MRI (CMR) is increasingly used for surgical planning and serial monitoring of children with congenital heart disease (CHD). For small children, general anesthesia (GA) is required. We describe our experience of the safety of GA for pediatric CMR, using data collected prospectively over 3 years.

METHODS

All consecutive infants undergoing GA for CMR at our institution, between November 2005 and May 2008, were included. Informed and written consent to participate in research investigation was acquired from the guardians of every patient prior to CMR. The cardiac anesthetist completed a standardized data collection form during each procedure. Information collected included demographics, diagnosis, surgical history, anesthetic management, significant incidents, and discharge circumstances.

RESULTS

A total of 120 patients with varying cardiac physiology and a range of hemodynamics underwent GA for CMR during the study period. Gas induction was predominantly used, even in those with impaired ventricular function. The majority (71%) of procedures were undertaken without significant incident. Minor adverse incidents were recorded in 32 patients, mild hypotension being most frequent. One major adverse event occurred. A patient with hypoplastic left heart syndrome (HLHS) suffered hypotension then cardiac arrest in the scanner. This patient was successfully resuscitated.

CONCLUSION

Although the majority of cases were safe and without incident, the complication rate in children with CHD receiving a GA for CMR is higher than in the general pediatric population. This reinforces the need for a senior, multidisciplinary team to be involved in the care of these children during imaging.

Flow-sensitive four-dimensional magnetic resonance imaging facilitates and improves the accurate diagnosis of partial anomalous pulmonary venous drainage

OBJECTIVES

To assess if flow-sensitive four-dimensional velocity-encoded cine magnetic resonance imaging adds value in diagnosing patients with suspected partial anomalous pulmonary venous drainage.

METHODS

In six patients with echocardiographically suspected partial anomalous pulmonary venous drainage, anatomy was evaluated using standard magnetic resonance imaging including angiography. Functional analysis included shunt calculations from flow measurements. We used four-dimensional velocity-encoded cine magnetic resonance imaging for visualisation of maldraining pulmonary veins and quantification of flow via the maldraining veins and interatrial communications, if present.

RESULTS

In all patients, the diagnosis of partial anomalous pulmonary venous drainage was confirmed by standard magnetic resonance imaging. Shunt volumes ranged from 1.4:1 to 4.7:1. Drainage sites were the superior caval vein (n = 5) or the vertical vein (n = 1). Multiple maldraining pulmonary veins were found in three patients. Pulmonary arteries and veins could be clearly distinguished by selective visualisation using four-dimensional velocity-encoded cine magnetic resonance imaging. Flow measured individually in maldraining pulmonary veins in six patients and across the interatrial communication in three patients revealed a percentage of the overall shunt volume of 30-100% and 58-70%, respectively.

CONCLUSION

Selective visualisation of individual vessels and their flow characteristics by four-dimensional velocity-encoded cine magnetic resonance imaging facilitates in distinguishing adjacent pulmonary arteries and veins and thus improves the accurate diagnosis of maldraining pulmonary veins. By detailed quantification of shunt volumes, additional information for planning of treatment strategies is provided. This method adds clinical value and might replace contrast-enhanced magnetic resonance angiography in these patients in the future.

Valvular and hemodynamic assessment with CMR

Cardiovascular magnetic resonance is able to provide a comprehensive assessment of valvular and hemodynamic function, including quantification of valve regurgitation and other flows, and accurate cardiac volumes and mass for assessing the effect on both ventricles. Combined with the ability to image all areas of the heart (including difficult areas, such as the right ventricle and pulmonary veins), it is an ideal technique for investigating patients who have heart failure in whom these areas need to be examined.

Partial anomalous pulmonary venous drainage in young pediatric patients: the role of magnetic resonance imaging

Studies of larger patient groups for systematic assessment of the anatomical accuracy of magnetic resonance imaging (MRI) for partial anomalous pulmonary venous drainage (PAPVD) have been performed so far only in adults. This study was undertaken to evaluate whether MRI can precisely depict pulmonary venous anatomy in infants and young children. Data on 26 children under 10 years old that underwent MRI over the past 2 years for suspected PAPVD were assessed. The MRI protocol included shunt quantification by velocity-encoded cine as well as morphological and functional assessment by multislice multiphase and contrast-enhanced MR techniques. MRI was performed in the compliant patient in breath-hold (n = 8; age range, 4.6-9.5 years) and in the noncompliant patient in conscious-sedation free breathing (n = 18; age range, 0.4 to 7.5 years). In 22 patients, PAPVD was diagnosed with MRI and confirmed during surgery. In four patients with large atrial septal defects not accessible to percutaneous closure, normal pulmonary venous return was demonstrated by MRI and confirmed during surgery. MRI under conscious sedation accurately specifies the anatomy of pulmonary veins in infants and small children. Therefore, we suggest performing MRI in patients with inconclusive transthoracic echocardiographic results in the preoperative assessment of PAPVD.

Atrial septal defect combined with partial anomalous pulmonary venous return: complete anatomic and functional characterization by cardiac magnetic resonance

The presented case regards a 17-year-old male with new-onset right bundle branch block and significantly enlarged right-heart sections as the only pathologic finding on transthoracic echocardiography. Cardiac magnetic resonance (CMR) revealed the presence of a superior sinus venosus atrial septal defect associated with a partial anomalous pulmonary venous return, with the right upper lobe pulmonary vein draining into the superior vena cava. CMR has developed in recent years into an accurate modality for non-invasive evaluation of patients with congenital heart disease, especially through improvements in quality and speed of image acquisition. With echocardiography, sinus venosus defects and anomalous pulmonary vein drainage may be more easily detected by a transoesophageal approach because of the proximity of the transducer to the atrial septum. CMR may be specifically recommended as an alternative to transoesophageal echocardiography in any patient with an unexplained dilatation of the right ventricle.

Anatomical and Functional Evaluation of Pulmonary Veins in Children by Magnetic Resonance Imaging

Pulmonary vein pathologies often present a diagnostic challenge. Among the different imaging modalities used for the evaluation of pulmonary veins, magnetic resonance is the most comprehensive in assessing anatomy and pathophysiology at the same time. Bright blood cine sequences and contrast-enhanced magnetic resonance angiography outline the course and connections of the pulmonary veins. Phase-contrast velocity mapping measures flow patterns, velocities, and volumes throughout the pulmonary circulation. This paper reviews contemporary utilization of magnetic resonance in the evaluation of pulmonary venous abnormalities in children, based on our experience over the last 5 years and on that of other investigators. We summarize how magnetic resonance imaging enhances our understanding of pulmonary vein physiology and how it can influence the diagnostic approach to children and adults with a pulmonary venous pathology, and we discuss its limitations.