Ultrafast three-dimensional contrast-enhanced magnetic resonance angiography and imaging in the diagnosis of partial anomalous pulmonary venous drainage

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.

Golden ratio stack of spirals for flexible angiographic imaging: Proof of concept in congenital heart disease

PURPOSE

In this study, a golden ratio stack of spiral (GRASS) sequence that used both golden step and golden angle ordering was implemented. The aim was to demonstrate that GRASS acquisitions could be flexibly reconstructed as both cardiac-gated and time-resolved angiograms.

METHODS

Image quality of time-resolved and cardiac-gated reconstructions of the GRASS sequence were compared to 3 conventional stack of spirals (SoS) acquisitions in an in silico model. In 10 patients, the GRASS sequence was compared to conventional breath hold angiography (BH-MRA) in terms of image quality and for vessel measurement. Vessel measurements were also compared to cine images.

RESULTS

In the cardiac-gated in silico model, the image quality of GRASS was superior to regular and golden-angle with regular step SoS approaches. In the time-resolved model, GRASS image quality was comparable to the golden-angle with regular step technique and superior to regular SoS acquisitions. In patients, there was no difference in qualitative image scores between GRASS and BH-MRA, but SNR was lower. There was good agreement in vessel measurements between the GRASS reconstructions and conventional MR techniques (BH-MRA: 29.8 ± 5.6 mm, time-resolved GRASS-MRA: 29.9 ± 5.4 mm, SSFP diastolic: 29.4 ± 5.8 mm, cardiac-gated GRASS-MRA diastolic: 29.5 ± 5.5 mm, P > 0.87).

CONCLUSION

We have demonstrated that the GRASS acquisition enables flexible reconstruction of the same raw data as both time-resolved and cardiac-gated volumes. This may enable better interrogation of anatomy in congenital heart disease.

ACR Appropriateness Criteria® Suspected Pulmonary Hypertension

Pulmonary hypertension may be idiopathic or related to a large variety of diseases. Various imaging examinations that may be helpful in diagnosing and determining the etiology of pulmonary hypertension are discussed. Imaging examinations that may aid in the diagnosis of pulmonary hypertension include chest radiography, ultrasound echocardiography, ventilation/perfusion scans, CT, MRI, right heart catheterization, pulmonary angiography, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Free breathing contrast-enhanced time-resolved magnetic resonance angiography in pediatric and adult congenital heart disease

BACKGROUND

Contrast enhanced magnetic resonance angiography (MRA) is generally performed during a long breath-hold (BH), limiting its utility in infants and small children. This study proposes a free-breathing (FB) time resolved MRA (TRA) technique for use in pediatric and adult congenital heart disease (CHD).

METHODS

A TRA sequence was developed by combining spiral trajectories with sensitivity encoding (SENSE, x4 kx-ky and x2 kz) and partial Fourier (75% in kz). As no temporal data sharing is used, an independent 3D data set was acquired every ~1.3s, with acceptable spatial resolution (~2.3x2.3x2.3 mm). The technique was tested during FB over 50 consecutive volumes. Conventional BH-MRA and FB-TRA data was acquired in 45 adults and children with CHD. We calculated quantitative image quality for both sequences. Diagnostic accuracy was assessed in all patients from both sequences. Additionally, vessel measurements were made at the sinotubular junction (N = 43), proximal descending aorta (N = 43), descending aorta at the level of the diaphragm (N = 43), main pulmonary artery (N = 35), left pulmonary artery (N = 35) and the right pulmonary artery (N = 35). Intra and inter observer variability was assessed in a subset of 10 patients.

RESULTS

BH-MRA had significantly higher homogeneity in non-contrast enhancing tissue (coefficient of variance, P <0.0001), signal-to-noise ratio (P <0.0001), contrast-to-noise ratio (P <0.0001) and relative contrast (P = 0.02) compared to the FB-TRA images. However, homogeneity in the vessels was similar in both techniques (P = 0.52) and edge sharpness was significantly (P <0.0001) higher in FB-TRA compared to BH-MRA. BH-MRA provided overall diagnostic accuracy of 82%, and FB-TRA of 87%, with no statistical difference between the two sequences (P = 0.77). Vessel diameter measurements showed excellent agreement between the two techniques (r = 0.98, P <0.05), with no bias (0.0 mm, P = 0.71), and clinically acceptable limits of agreement (-2.7 to +2.8 mm). Inter and intra observer reproducibility showed good agreement of vessel diameters (r>0.988, P<0.0001), with negligible biases (between -0.2 and +0.1mm) and small limits of agreement (between -2.4 and +2.5mm).

CONCLUSIONS

We have described a FB-TRA technique that is shown to enable accurate diagnosis and vessel measures compared to conventional BH-MRA. This simplifies the MRA technique and will enable angiography to be performed in children and adults whom find breath-holding difficult.

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.

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.

Magnetic resonance imaging of pediatric lung parenchyma, airways, vasculature, ventilation, and perfusion: state of the art

Magnetic resonance (MR) imaging is a noninvasive imaging modality, particularly attractive for pediatric patients given its lack of ionizing radiation. Despite many advantages, the physical properties of the lung (inherent low signal-to-noise ratio, magnetic susceptibility differences at lung-air interfaces, and respiratory and cardiac motion) have posed technical challenges that have limited the use of MR imaging in the evaluation of thoracic disease in the past. However, recent advances in MR imaging techniques have overcome many of these challenges. This article discusses these advances in MR imaging techniques and their potential role in the evaluation of thoracic disorders in pediatric patients.

Guidelines and protocols for cardiovascular magnetic resonance in children and adults with congenital heart disease: SCMR expert consensus group on congenital heart disease

Cardiovascular magnetic resonance (CMR) has taken on an increasingly important role in the diagnostic evaluation and pre-procedural planning for patients with congenital heart disease. This article provides guidelines for the performance of CMR in children and adults with congenital heart disease. The first portion addresses preparation for the examination and safety issues, the second describes the primary techniques used in an examination, and the third provides disease-specific protocols. Variations in practice are highlighted and expert consensus recommendations are provided. Indications and appropriate use criteria for CMR examination are not specifically addressed.

Partial anomalous pulmonary venous return and atrial septal defect in adult patients detected with 128-slice multidetector computed tomography

The present series describes a group of adults with left-to-right shunts including partial anomalous pulmonary venous return (PAPVR) and/or an atrial septal defect (ASD) evaluated with ECG-gated 128-slice multidetector computed tomography (MDCT). PAPVR is defined as a left-to-right shunt where one or more, but not all, pulmonary veins drain into a systemic vein or the right atrium. PAPVR involving the right upper pulmonary vein can be associated with a sinus venosus ASD. The presence, course, number of anomalous veins and associated cardiovascular defects can be reliably observed by 128-slice MDCT angiography.

The role of cardiovascular magnetic resonance in pediatric congenital heart disease

Cardiovascular magnetic resonance (CMR) has expanded its role in the diagnosis and management of congenital heart disease (CHD) and acquired heart disease in pediatric patients. Ongoing technological advancements in both data acquisition and data presentation have enabled CMR to be integrated into clinical practice with increasing understanding of the advantages and limitations of the technique by pediatric cardiologists and congenital heart surgeons. Importantly, the combination of exquisite 3D anatomy with physiological data enables CMR to provide a unique perspective for the management of many patients with CHD. Imaging small children with CHD is challenging, and in this article we will review the technical adjustments, imaging protocols and application of CMR in the pediatric population.

Sinus venosus atrial septal defect in adults: utility of cardiovascular MRI in resolving this diagnostic dilemma

Sinus venosus atrial septal defect (SV-ASD) can be a challenging diagnostic problem. It can present with non-specific signs and symptoms and, on imaging, can mimic other causes of right heart dilatation. Transthoracic echocardiography using standard scan planes may be limited, due to the defect and any associated anomalous pulmonary venous drainage lying outside the confines of the fossa ovalis. At our institution, we use cardiovascular magnetic resonance imaging (CMRI) as a problem-solving tool in these patients. In this article, we discuss the utility of CMRI in establishing the diagnosis by presenting our recent experience and illustrating it with sample cases. We wish to highlight the problems relating to making a diagnosis of SV-ASD in adult patients, and how CMRI has contributed to overcoming these in our practice.

64-slice CT imaging in a case of total anomalous pulmonary venous circulation

For long, catheter angiography has been the investigation of choice for the diagnosis of congenital anomalies of the heart such as total anomalous pulmonary venous circulation (TAPVC). In the last few years, MRI and multislice CT scan have also been introduced for this purpose. We report a case where 64-slice CT scan was found very useful in the evaluation of TAPVC.

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.

Diagnostic tools in the preoperative evaluation of children with anomalous pulmonary venous connections

Pulmonary venous abnormalities are generally diagnosed by echocardiography and often confirmed by cardiac catheterization. Although angiography has been the gold standard for evaluation it carries certain inherent risks, especially in small and sick infants. In this study we retrospectively assessed the utility of magnetic resonance angiography (MRA) and computed tomography angiography (CTA) in the evaluation of pulmonary venous abnormalities in pediatric patients. The results were compared with operative findings. We reviewed nine patients with total APVC and four with partial APVC. Twelve patients were infant (age range: 1 day to 8 months) and the other was 16 years old. MRA and/or CTA clearly visualized the anomalous drainage of pulmonary veins in all patients. Cardiac catheterization was performed five patients with one total anomalous pulmonary venous connection and four with partial anomalous pulmonary venous connection. Ten patients were operated on. Diagnoses of patients were confirmed by operative findings. In Conclusions, MR and CT angiography allow detailed and comprehensive evaluation of the APVC and are good diagnostic modalities for use in the preoperative assessment of the anomaly in pediatric patients.

Contrast-enhanced MR angiography of thoracic vascular malformations in children

To plan an effective management of thoracic vascular malformations, clinicians must have a clear understanding of the anatomy. Although echocardiography and angiography are the leading imaging modalities in patients with congenital cardiovascular anomalies, magnetic resonance (MR) imaging and computed tomography (CT) are valuable noninvasive adjuncts. MR imaging and CT are effective in demonstrating the complex extracardiac morphology and yield helpful information that can change the treatment plan. Although recent reports state the usefulness of multidetector CT (MDCT), in terms of pediatric population, the significance of radiation exposure should be taken into account. Thus, contrast enhanced MR angiography, as a guide in planning surgery, seems to be the best alternative to conventional angiography in the diagnosis of congenital vascular malformations. In this review, the diagnostic features of thoracic vascular malformations in pediatric population are discussed, and, the potential uses of contrast-enhanced MR angiography are emphasized with the retrospective evaluation of imaging findings in 114 examinations.

Cardiac magnetic resonance imaging evaluation of sinus venosus defects: comparison to surgical findings

Sinus venosus defect (SVD) is an uncommon type of interatrial communication in which cardiac magnetic resonance (CMR) is increasingly used as an alternative imaging modality. The goal of this study was to determine the accuracy of CMR in patients with SVD compared with surgical findings. The diagnostic studies and operative reports of all patients who had CMR followed by surgical repair of SVD (n = 16) from 1996 to 2005 were reviewed and discrepancies were recorded. CMR studies included assessment of anatomy (evaluated by a combination of gradient echo cine, spin echo, and gadolinium-enhanced three-dimensional magnetic resonance angiography), ventricular volumes and function, and flow measurements. The median age at CMR was 14 years (range, 0.4-42). Compared with operative findings, there were no major discrepancies with CMR. The SVD was clearly imaged in all patients and 36 anomalously draining pulmonary veins were identified. The median pulmonary-to-systemic flow ratio was 2.4 (range, l.3-4.6). Patients had an average of 1.7 previous diagnostic tests (range, 1-3; 19 transthoracic echo, 5 catheterizations, and 3 transesophageal echo). Before CMR, SVD was diagnosed in 1 patient, suspected in 7, and not suspected in 8. Additional unsuspected findings identified by CMR included malposition of septum primum (n = 2), left superior vena cava to coronary sinus (n = 2), and aortic arch anomalies (n = 2). CMR accurately depicts SVD anatomy and associated anomalous pulmonary venous drainage, provides quantitative information on the hemodynamic burden, and reveals additional cardiovascular abnormalities. This experience indicates that CMR provides the information necessary for surgical planning of SVD repair.

Anomaly of the left atrium in patients with atrial fibrillation detected by ECG-gated multi-slice computed tomography

We illustrate pulmonary vein anatomy in 2 patients undergoing multi-slice computed tomography (MSCT) scanning prior to atrial fibrillation ablation, including anomaly of the pulmonary vein. The anomalous variations need to be investigated before catheter procedure, because of the anomalous variations. Non-invasive imaging using MSCT could have important clinical implications and provide the physicians useful information on morphological feature in patients with atrial fibrillation before catheter ablation.

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

BACKGROUND

Diagnosis of partial anomalous pulmonary venous return is usually suspected by echocardiography and often confirmed by cardiac catheterization. Magnetic resonance imaging is a powerful non-invasive diagnostic tool that can give accurate insight on systemic and pulmonary veins, cardiac anatomy and physiopathology.

AIM

To test the diagnostic accuracy of magnetic resonance in patient with suspected partial anomalous pulmonary venous return.

CASE PRESENTATION

Twenty consecutive patients (10 male, mean age: 27+/-20 years) with suspected partial anomalous pulmonary venous return underwent a magnetic resonance study comprehensive of Gadolinium-enhanced three-dimensional magnetic resonance angiography and phase-velocity-contrast in order to evaluate pulmonary and systemic venous anatomy and QP/QS. In 14 of them a cardiac catheterization was also performed. Anatomy findings and QP/QS result of both exams were compared. Sixteen patients underwent surgical correction. In the other four patients with QP/QS<1.5, surgical correction was not indicated according to the literature (1). Among patients who had both magnetic resonance and cardiac catheterization (14 patients) anatomical findings were concordant in 12 of them. In all operated patients, surgical findings were concordant with MRI report. There was a good correlation between magnetic resonance and cardiac catheterization QP/QS evaluation (mean value 2.23 and 2.4, respectively).

CONCLUSION

In patients with suspected anomalous pulmonary venous return, magnetic resonance provides a comprehensive evaluation of pulmonary venous return and the amount of shunt, overcoming most of the limitations of echocardiography. Therefore magnetic resonance is a powerful diagnostic tool for indicating therapeutic management and surgical strategies for this group of patients, and can be considered a non-invasive alternative to cardiac catheterization.

Role of magnetic resonance angiography in the diagnosis of major aortopulmonary collateral arteries and partial anomalous pulmonary venous drainage

BACKGROUND

Accurate diagnosis of major aortopulmonary collaterals (MAPCAs) and partial anomalous pulmonary venous drainage (PAPVD) in adult patients with congenital heart disease is important but problematic. Three-dimensional contrast-enhanced magnetic resonance angiography (MRA) provides a minimally invasive technique to allow detailed studies in a single breath-hold.

METHODS AND RESULTS

We assessed the role of contrast-enhanced 3D MRA in 29 consecutive adult patients with a diagnosis of MAPCAs (n=16) or PAPVD (n=13) made by echocardiogram, cardiac catheterization, or surgical inspection. MRA was performed with a 3D spoiled gradient-echo technique with intravenous gadolinium-DTPA (0.2 mmol/kg). In both types of pathology, there was excellent correlation between MRA and the cardiac catheterization, echocardiogram, or surgical inspection. Additional information was gained for patients with MAPCAs on confluence and size of pulmonary arteries (n=13 had central arteries), pulmonary artery stenosis (n=3), aneurysmal dilatation of pulmonary artery (n=1), and additional anomalous vascular abnormality (n=3). Shunt assessment, where present (9 of 16), showed patency in all cases (100%). For adults with PAPVD, further information was obtained on drainage origin (n=11). There were no complications.

CONCLUSIONS

Contrast-enhanced 3D MRA provides a fast, noninvasive, radiation-free method of accurate and comprehensive diagnosis of MAPCAs and PAPVD in adult patients.

Cardiovascular shunts: MR imaging evaluation

Magnetic resonance (MR) imaging has become an important tool for the accurate and noninvasive assessment of congenital heart disease. Because more precise delineation of anatomy and evaluation of function can be obtained with MR imaging than with either echocardiography or angiography, MR imaging is frequently used to evaluate cardiovascular shunt lesions. It is essential that imaging specialists be able to recognize the MR imaging features of various kinds of shunts, including supracristal ventricular septal defect, atrioventricular septal defect, and partial anomalous pulmonary venous connection. MR imaging is particularly useful for evaluating shunt severity, which can be expressed quantitatively as the ratio of pulmonary flow to systemic flow. This ratio can be estimated accurately with the use of either volumetric cine MR imaging or velocity-encoded cine MR imaging.

Assessment of the anomalous pulmonary circulation by dynamic contrast-enhanced MR angiography in under four seconds

The purpose of this study was to demonstrate the initial results of the dynamic contrast-enhanced MRA in under four seconds in the assessment of anomalous pulmonary circulation. We performed dynamic contrast enhanced MRA on ten patients with a temporal resolution of 2-3 sec for each phase. Five patients had pulmonary vascular anomaly and five patients had reconstructed pulmonary circulation. On nine patients catheter angiography was performed for the correlation. Dynamic contrast-enhanced MRA successfully demonstrated congenital pulmonary vascular anomalies and the pathway of anomalous pulmonary circulation in our series. With the improved temporal and spatial resolution, the dynamic contrast-enhanced MRA can be used in children and infants for the assessment of congenital vascular disease.

Gadolinium-enhanced three-dimensional magnetic resonance angiography of pulmonary and systemic venous anomalies

OBJECTIVE

The goal of this study was to evaluate the diagnostic value of gadolinium (Gd)-enhanced three-dimensional (3D) magnetic resonance angiography (MRA) in patients with congenital and acquired anomalies of the pulmonary and systemic veins.

BACKGROUND

Gadolinium-enhanced 3D MRA is a fast magnetic resonance imaging technique that has shown great promise in the evaluation of large and medium-sized arteries. However, its application to venous anomalies has not been studied in detail.

METHODS

The study retrospectively analyzed all patients who underwent Gd-enhanced 3D MRA examination from January 1998 through January 2001, were diagnosed with anomalies of the pulmonary or systemic veins and had additional diagnostic data available for comparison with the MRA findings.

RESULTS

Sixty-one patients (age 1 day to 60 years) were included. Image acquisition was completed in 29 +/- 6.9 s. Pulmonary venous anomalies were found in 37 patients, systemic venous anomalies in 17 patients and both pulmonary and systemic venous anomalies in 7 patients. Compared with available diagnostic information by other modalities, all known or suspected venous anomalies were imaged by 3D MRA. In three patients, catheterization did not detect anomalies of the pulmonary veins that were subsequently diagnosed by MRA. The 3D MRA diagnoses were followed by 10 interventional catheterization procedures and 15 operations. In 74% of patients, 3D MRA either diagnosed previously unsuspected venous anomalies (28%) or added new clinically important information (46%). The mechanism of pulmonary vein compression in eight patients was determined by MRA but not by other imaging modalities. Using a five-level grading system for MRA image quality (1 = nondiagnostic; 5 = excellent), the average grade was 4.6 +/- 0.6, with a 0.28 +/- 0.6 mean grade difference between two independent observers.

CONCLUSIONS

Gadolinium-enhanced 3D MRA is capable of rapidly and accurately diagnosing a wide spectrum of pulmonary and systemic venous anomalies and is a useful noninvasive alternative to diagnostic catheterization.

MR imaging of congenital heart diseases in adolescents and adults

Echocardiography and catheterization angiography suffer certain limitations in the evaluation of congenital heart diseases in adults, though these are overcome by MRI, in which a wide field-of view, unlimited multiplanar imaging capability and three-dimensional contrast-enhanced MR angiography techniques are used. In adults, recently introduced fast imaging techniques provide cardiac MR images of sufficient quality and with less artifacts. Ventricular volume, ejection fraction, and vascular flow measurements, including pressure gradients and pulmonary-to-systemic flow ratio, can be calculated or obtained using fast cine MRI, phase-contrast MR flow-velocity mapping, and semiautomatic analysis software. MRI is superior to echocardiography in diagnosing partial anomalous pulmonary venous connection, unroofed coronary sinus, anomalies of the pulmonary arteries, aorta and systemic veins, complex heart diseases, and postsurgical sequelae. Biventricular function is reliably evaluated with cine MRI after repair of tetralogy of Fallot, and Senning's and Mustard's operations. MRI has an important and growing role in the morphologic and functional assessment of congenital heart diseases in adolescents and adults.