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Cardiovascular Shunts: MR Imaging Evaluation¹

¹ From the Department of Radiology, Box 0628, University of California, 505 Parnassus Ave, San Francisco, CA 94143-0628. Recipient of a Certificate of Merit award for an education exhibit at the 2002 RSNA scientific assembly. Received February 3, 2003; revision requested March 20 and received May 1; accepted May 20. Address correspondence to G.P.R. (e-mail: gautham.reddy@radiology.ucsf.edu).

	Abstract

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

 
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.

© RSNA, 2003

Index Terms: Heart, flow dynamics, 50.12144 • Heart, function • Heart, MR, 50.1214 • Magnetic resonance (MR), cine study • MR, vascular studies

	Introduction

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

 
Magnetic resonance (MR) imaging has become an important tool for the delineation of cardiac anatomy and the quantification of physiologic function (1–7). It has multiple capabilities for the evaluation of congenital heart diseases including cardiovascular shunts. Morphologic information about shunts is provided by electrocardiography (ECG)-gated spin-echo and cine MR imaging. Shunt volume can be estimated by using volumetric cine MR imaging or velocity-encoded cine MR imaging. MR angiography permits high-resolution three-dimensional examination of vessels and can noninvasively establish the presence of anomalous pulmonary veins that lead to shunting (8,9).

Echocardiography and angiography have traditionally been the primary imaging modalities used for the evaluation of cardiac shunts. Echocardiography is sensitive and noninvasive but has a limited acoustic window. Although angiography is frequently considered the standard method for achieving definitive diagnosis of cardiac shunts, it is invasive and requires the use of iodinated contrast material. Computed tomography (CT) can demonstrate structural heart disease such as septal defects and anomalous pulmonary venous and arterial anatomy; however, functional evaluation of shunts with CT has not been described extensively. MR imaging has emerged as an accurate and noninvasive alternative for the depiction of anatomy and the assessment of function. This article surveys the MR imaging techniques that are most useful for detecting, localizing, and quantifying shunts in atrial, ventricular, and atrioventricular septal defects; patent ductus arteriosus; aortopulmonary window; and partial anomalous pulmonary venous return (PAPVR) (Tables 1, 2).

The sinus venosus and the septa secundum and primum can be clearly visualized with MR imaging in the transverse plane or along the short axis. Spin-echo MR imaging has been found accurate for the detection and localization of atrial septal defect with greater than 90% sensitivity and specificity (13). MR imaging criteria used to establish the presence of atrial septal defect include depiction of the defect at two adjacent anatomic levels on multisection transverse images or at the same anatomic level on single-section images acquired during multiple phases of the cardiac cycle (14). MR images of patients with an atrial septal defect involving the sinus venosus show a defect in the portion of the atrial septum between the superior vena cava and the left atrium (Fig 1). In patients with a defect of the septum secundum, the defect occurs in the middle of the atrial septum (Figs 2, 3). The normally thinned tissue in the region of the fossa ovalis, which may exhibit little or no signal intensity on MR images, is sometimes mistaken for a defect in the septum secundum (Fig 4). An intact atrial septum, however, thins gradually toward the site of signal intensity absence (Fig 4). In contrast, in a defect of the septum secundum, the edge of the adjacent septum is thickened (Figs 2, 3). A defect of the septum primum is frequently associated with a defect of the atrioventricular valve (atrioventricular septal defect). The use of MR imaging for the evaluation of atrioventricular septal defect is described later in this article.

View larger version (161K): [in this window] [in a new window] [Download PPT slide]   Figure 1a.  Sinus venosus atrial septal defect in a 50-year-old woman with dyspnea on exertion. Axial ECG-gated spin-echo (a) and cine (b) MR images show a defect (arrow) in the portion of the atrial septum between the superior vena cava (SVC) and the left atrium (LA). Ao = ascending aorta, PA = main pulmonary artery.

View larger version (133K): [in this window] [in a new window] [Download PPT slide]   Figure 1b.  Sinus venosus atrial septal defect in a 50-year-old woman with dyspnea on exertion. Axial ECG-gated spin-echo (a) and cine (b) MR images show a defect (arrow) in the portion of the atrial septum between the superior vena cava (SVC) and the left atrium (LA). Ao = ascending aorta, PA = main pulmonary artery.

View larger version (142K): [in this window] [in a new window] [Download PPT slide]   Figure 2.  Atrial septal defect in the septum secundum in a 23-year-old man with a heart murmur. Axial ECG-gated spin-echo image shows a defect (arrow) in the middle of the septum and thickening (*) at the edge of the septum adjacent to the defect. LA = left atrium, RA = right atrium.

View larger version (173K): [in this window] [in a new window] [Download PPT slide]   Figure 3.  Atrial septal defect in the septum secundum in a 45-year-old man with dyspnea on exertion. Axial ECG-gated cine MR image shows a defect (arrow) in the middle of the atrial septum. LA = left atrium, RA = right atrium.

View larger version (150K): [in this window] [in a new window] [Download PPT slide]   Figure 4.  Normal atrial septum. Axial ECG-gated spin-echo image shows little signal intensity in the region of the fossa ovalis, in the interatrial septum (arrow)—a finding that could lead to a false-positive identification of atrial septal defect in the septum secundum.

View larger version (121K): [in this window] [in a new window] [Download PPT slide]   Figure 5a.  Eisenmenger syndrome in a 36-year-old woman. Axial ECG-gated spin-echo images show atrial septal defect (arrow in a) and marked enlargement of the main pulmonary artery (PA) (b), consistent with pulmonary arterial hypertension. Long-standing severe pulmonary arterial hypertension can result in the shunt reversal that characterizes Eisenmenger syndrome. Ao = ascending aorta, LA = left atrium, RA = right atrium.

View larger version (129K): [in this window] [in a new window] [Download PPT slide]   Figure 5b.  Eisenmenger syndrome in a 36-year-old woman. Axial ECG-gated spin-echo images show atrial septal defect (arrow in a) and marked enlargement of the main pulmonary artery (PA) (b), consistent with pulmonary arterial hypertension. Long-standing severe pulmonary arterial hypertension can result in the shunt reversal that characterizes Eisenmenger syndrome. Ao = ascending aorta, LA = left atrium, RA = right atrium.

View larger version (156K): [in this window] [in a new window] [Download PPT slide]   Figure 6a.  Membranous ventricular septal defect in an 11-month-old boy with a heart murmur. (a) Axial ECG-gated spin-echo image shows a defect (arrow) in the membranous part of the septum. (b) Axial gradient-echo cine image shows a flow jet (*) across the defect into the right ventricle, indicating a left-to-right shunt.

View larger version (160K): [in this window] [in a new window] [Download PPT slide]   Figure 6b.  Membranous ventricular septal defect in an 11-month-old boy with a heart murmur. (a) Axial ECG-gated spin-echo image shows a defect (arrow) in the membranous part of the septum. (b) Axial gradient-echo cine image shows a flow jet (*) across the defect into the right ventricle, indicating a left-to-right shunt.

View larger version (159K): [in this window] [in a new window] [Download PPT slide]   Figure 7.  Membranous ventricular septal defect in a 24-year-old man with tetralogy of Fallot. Coronal ECG-gated cine MR image shows a membranous ventricular septal defect (arrow) with an overriding aorta (Ao). (Courtesy of James Scatliff, MD, Department of Radiology, University of North Carolina, Chapel Hill)

View larger version (158K): [in this window] [in a new window] [Download PPT slide]   Figure 8a.  Supracristal ventricular septal defect in an asymptomatic 42-year-old man with a systolic murmur. (a) Axial ECG-gated spin-echo image shows a defect (arrow) between the base of the aorta and the right ventricular (RV) infundibulum. (b) Axial gradient-echo systolic cine image shows a flow jet (*) from the left ventricle into the right ventricular outflow tract, indicating a left-to-right shunt. (c) Sagittal spin-echo image shows a prolapse (arrow) of the posterior aortic sinus of Valsalva.

View larger version (167K): [in this window] [in a new window] [Download PPT slide]   Figure 8b.  Supracristal ventricular septal defect in an asymptomatic 42-year-old man with a systolic murmur. (a) Axial ECG-gated spin-echo image shows a defect (arrow) between the base of the aorta and the right ventricular (RV) infundibulum. (b) Axial gradient-echo systolic cine image shows a flow jet (*) from the left ventricle into the right ventricular outflow tract, indicating a left-to-right shunt. (c) Sagittal spin-echo image shows a prolapse (arrow) of the posterior aortic sinus of Valsalva.

View larger version (176K): [in this window] [in a new window] [Download PPT slide]   Figure 8c.  Supracristal ventricular septal defect in an asymptomatic 42-year-old man with a systolic murmur. (a) Axial ECG-gated spin-echo image shows a defect (arrow) between the base of the aorta and the right ventricular (RV) infundibulum. (b) Axial gradient-echo systolic cine image shows a flow jet (*) from the left ventricle into the right ventricular outflow tract, indicating a left-to-right shunt. (c) Sagittal spin-echo image shows a prolapse (arrow) of the posterior aortic sinus of Valsalva.

	Supracristal Ventricular Septal Defect

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

 
MR imaging plays an important role in the diagnosis and management of supracristal ventricular septal defect. Although echocardiography is the primary imaging modality for the evaluation of cardiac shunts, it is less accurate for defining supracristal ventricular septal defect. Cardiac angiography is more accurate in localizing the lesion, but it involves catheterization and ionizing radiation, with attendant risks to the patient. MR imaging is an effective and noninvasive alternative (21). ECG-gated spin-echo MR images typically depict a characteristic defect between the base of the aorta and the right ventricular infundibulum (Fig 8a), and cine MR images often reveal a systolic flow jet from the left ventricle into the right ventricular outflow tract, indicating a left-to-right shunt (Fig 8b). Shunt severity can be quantified by calculating the ratio of pulmonary flow to systemic flow, with flow values obtained from velocity-encoded cine MR images (16,22). Furthermore, MR imaging can be used to diagnose complications of supracristal ventricular septal defect, including aortic valve prolapse with resultant aortic regurgitation and secondary right ventricular enlargement or hypertrophy (21) (Fig 8c).

	Atrioventricular Septal Defect

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

 
Atrioventricular septal defect, formerly known as endocardial cushion defect, manifests as a common atrioventricular valve with an abnormal arrangement of valvular leaflets and variable deficiency of the atrial septum primum and the ventricular inlet septum (Figs 9–11) (14). Direct shunting from the left ventricle to the right atrium may occur through a defect in the atrioventricular septum, the small part of the ventricular septum that separates the inlet region of the left ventricle from the right atrium. In the most serious form of atrioventricular septal defect, all four chambers of the heart communicate, resulting in both left-to-right and right-to-left shunting (Figs 10, 11b). Although cyanosis may not be clinically apparent, pulmonary arterial hypertension tends to develop in infancy or early childhood in individuals with this form of atrioventricular septal defect. Clinically, the less severe forms resemble atrial septal defect, but the symptoms in atrioventricular septal defect are frequently more severe.

View larger version (165K): [in this window] [in a new window] [Download PPT slide]   Figure 9.  Atrioventricular septal defect. Axial ECG-gated spin-echo image shows an atrial septal defect (arrow) in the septum primum. The atrioventricular valve (arrowhead) is connected with the crest of the inlet ventricular septum. LA = left atrium, LV = left ventricle, RA = right atrium, RV = right ventricle.

View larger version (171K): [in this window] [in a new window] [Download PPT slide]   Figure 10.  Atrioventricular septal defect. Axial ECG-gated spin-echo image shows a complete atrioventricular septal defect with communication among all four chambers, as well as a large inlet ventricular septal defect (arrow). The single atrioventricular valve (arrowheads) spans both ventricular chambers.

View larger version (142K): [in this window] [in a new window] [Download PPT slide]   Figure 11a.  Atrioventricular septal defect in a 2-year-old girl. Axial ECG-gated spin-echo MR images show an atrial septal defect (arrow in a) in the septum primum and an inlet ventricular septal defect (arrow in b), which together produce communication among all four chambers. The right atrium (RA) is markedly enlarged and the right ventricle (*) is hypoplastic. LA = left atrium, LV = left ventricle.

View larger version (148K): [in this window] [in a new window] [Download PPT slide]   Figure 11b.  Atrioventricular septal defect in a 2-year-old girl. Axial ECG-gated spin-echo MR images show an atrial septal defect (arrow in a) in the septum primum and an inlet ventricular septal defect (arrow in b), which together produce communication among all four chambers. The right atrium (RA) is markedly enlarged and the right ventricle (*) is hypoplastic. LA = left atrium, LV = left ventricle.

	Patent Ductus Arteriosus

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

 
Patent ductus arteriosus accounts for approximately 10%–12% of all congenital heart disease (10). Clinical manifestations depend on the size of the duct and the difference between systemic and pulmonary vascular resistance. A small shunt does not cause hemodynamic derangement but may predispose patients to endocarditis; a large shunt causes a progressive increase in pulmonary arterial pressure, which may result eventually in Eisenmenger syndrome.

MR images can clearly depict the connection between the aorta and the pulmonary artery (Fig 12), showing the course of the ductus from the proximal descending aorta to the left pulmonary artery, just beyond the pulmonary arterial bifurcation. MR images also can show focal dilatation of the aorta at the site of ductal attachment (Fig 12a). The large aortic arch that frequently is associated with patent ductus arteriosus also can be seen on MR images. However, a narrow patent ductus may be missed at MR imaging, even with the use of thin (3-mm) sections (14). Echocardiography remains the main diagnostic study used for patent ductus arteriosus. Angiography is used to delineate anatomy and guide coil embolization of the patent ductus arteriosus. Although the accuracy of MR imaging for diagnosis of patent ductus arteriosus is as yet unknown, this modality may be useful for quantifying shunt volume.

View larger version (172K): [in this window] [in a new window] [Download PPT slide]   Figure 12a.  Patent ductus arteriosus in a 46-year-old woman with a heart murmur. (a) Gadolinium-enhanced MR angiographic image shows a patent ductus (arrow) connecting the proximal descending aorta (dAo) to the left pulmonary artery (LPA), just beyond the pulmonary arterial bifurcation. Note the focal dilatation of the aorta at the site of ductal attachment. (b, c) Axial (b) and oblique (c) MR angiographic images also depict the ductus (arrow). aAo = ascending aorta. (Courtesy of Ruth Carlos, MD, Department of Radiology, University of Michigan, Ann Arbor)

View larger version (125K): [in this window] [in a new window] [Download PPT slide]   Figure 12b.  Patent ductus arteriosus in a 46-year-old woman with a heart murmur. (a) Gadolinium-enhanced MR angiographic image shows a patent ductus (arrow) connecting the proximal descending aorta (dAo) to the left pulmonary artery (LPA), just beyond the pulmonary arterial bifurcation. Note the focal dilatation of the aorta at the site of ductal attachment. (b, c) Axial (b) and oblique (c) MR angiographic images also depict the ductus (arrow). aAo = ascending aorta. (Courtesy of Ruth Carlos, MD, Department of Radiology, University of Michigan, Ann Arbor)

View larger version (151K): [in this window] [in a new window] [Download PPT slide]   Figure 12c.  Patent ductus arteriosus in a 46-year-old woman with a heart murmur. (a) Gadolinium-enhanced MR angiographic image shows a patent ductus (arrow) connecting the proximal descending aorta (dAo) to the left pulmonary artery (LPA), just beyond the pulmonary arterial bifurcation. Note the focal dilatation of the aorta at the site of ductal attachment. (b, c) Axial (b) and oblique (c) MR angiographic images also depict the ductus (arrow). aAo = ascending aorta. (Courtesy of Ruth Carlos, MD, Department of Radiology, University of Michigan, Ann Arbor)

	Aortopulmonary Window

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

View larger version (154K): [in this window] [in a new window] [Download PPT slide]   Figure 13a.  Aortopulmonary window in a 20-year-old woman. Axial (a) and coronal (b) ECG-gated spin-echo images show a large defect (double arrow) between the lateral aspect of the ascending aorta (Ao) and the medial aspect of the main pulmonary artery (PA).

View larger version (157K): [in this window] [in a new window] [Download PPT slide]   Figure 13b.  Aortopulmonary window in a 20-year-old woman. Axial (a) and coronal (b) ECG-gated spin-echo images show a large defect (double arrow) between the lateral aspect of the ascending aorta (Ao) and the medial aspect of the main pulmonary artery (PA).

	Partial Anomalous Pulmonary Venous Return

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

Echocardiography and conventional angiography frequently are used for the diagnosis of PAPVR. Definitive diagnosis, however, may be difficult with echocardiography because of the limited acoustic window, especially in older children and adults (27,28). Although angiography is often considered the standard imaging modality for the diagnosis of anomalous pulmonary veins, it is invasive, and visualization of the veins may be difficult because of the dilution of hand-injected angiographic contrast material. CT, which also has been used to delineate the anatomy in PAPVR (29), requires the use of ionizing radiation and iodinated contrast material.

MR imaging has been used increasingly for the diagnosis of PAPVR because it provides a large field of view and excellent anatomic delineation without contrast material injection or ionizing radiation (Fig 14). MR imaging has been reported to have a greater sensitivity (95%) than do echocardiography (38%) and angiography (69%) in the prospective detection of pulmonary venous anomalies including PAPVR (30). In addition, MR imaging can depict atrial septal defects (13), which are frequently associated with PAPVR (Fig 14c).

View larger version (149K): [in this window] [in a new window] [Download PPT slide]   Figure 14a.  PAPVR in a 64-year-old woman. (a, b) Axial (a) and coronal (b) ECG-gated spin-echo images show drainage of the right upper lobe pulmonary vein (arrow) into the superior vena cava (SVC). Note the enlarged pulmonary artery (PA) in a, consistent with pulmonary arterial hypertension. (c) Axial spin-echo image at a lower level shows an associated atrial septal defect (arrow) in the sinus venosus. (d) Coronal gadolinium-enhanced MR angiographic image again shows drainage of the right upper lobe pulmonary vein (arrow) into the superior vena cava. The right upper lobe pulmonary vein is the most common anomalous vein. Ao = aorta, LA = left atrium.

View larger version (146K): [in this window] [in a new window] [Download PPT slide]   Figure 14b.  PAPVR in a 64-year-old woman. (a, b) Axial (a) and coronal (b) ECG-gated spin-echo images show drainage of the right upper lobe pulmonary vein (arrow) into the superior vena cava (SVC). Note the enlarged pulmonary artery (PA) in a, consistent with pulmonary arterial hypertension. (c) Axial spin-echo image at a lower level shows an associated atrial septal defect (arrow) in the sinus venosus. (d) Coronal gadolinium-enhanced MR angiographic image again shows drainage of the right upper lobe pulmonary vein (arrow) into the superior vena cava. The right upper lobe pulmonary vein is the most common anomalous vein. Ao = aorta, LA = left atrium.

View larger version (140K): [in this window] [in a new window] [Download PPT slide]   Figure 14c.  PAPVR in a 64-year-old woman. (a, b) Axial (a) and coronal (b) ECG-gated spin-echo images show drainage of the right upper lobe pulmonary vein (arrow) into the superior vena cava (SVC). Note the enlarged pulmonary artery (PA) in a, consistent with pulmonary arterial hypertension. (c) Axial spin-echo image at a lower level shows an associated atrial septal defect (arrow) in the sinus venosus. (d) Coronal gadolinium-enhanced MR angiographic image again shows drainage of the right upper lobe pulmonary vein (arrow) into the superior vena cava. The right upper lobe pulmonary vein is the most common anomalous vein. Ao = aorta, LA = left atrium.

View larger version (147K): [in this window] [in a new window] [Download PPT slide]   Figure 14d.  PAPVR in a 64-year-old woman. (a, b) Axial (a) and coronal (b) ECG-gated spin-echo images show drainage of the right upper lobe pulmonary vein (arrow) into the superior vena cava (SVC). Note the enlarged pulmonary artery (PA) in a, consistent with pulmonary arterial hypertension. (c) Axial spin-echo image at a lower level shows an associated atrial septal defect (arrow) in the sinus venosus. (d) Coronal gadolinium-enhanced MR angiographic image again shows drainage of the right upper lobe pulmonary vein (arrow) into the superior vena cava. The right upper lobe pulmonary vein is the most common anomalous vein. Ao = aorta, LA = left atrium.

View larger version (173K): [in this window] [in a new window] [Download PPT slide]   Figure 15.  PAPVR in a 71-year-old man with pulmonary arterial hypertension in whom no intracardiac shunt was found at echocardiography. Maximum-intensity projection image from MR angiographic data shows drainage of the right upper lobe pulmonary vein (arrow) into the superior vena cava.

View larger version (165K): [in this window] [in a new window] [Download PPT slide]   Figure 16.  PAPVR in a 45-year-old woman with hypogenetic lung syndrome (scimitar syndrome). Volume-rendered contrast-enhanced MR angiographic image shows drainage of the right upper lobe pulmonary vein (arrow) into the inferior vena cava at its junction with the right atrium (RA). This syndrome involves a combination of various defects, which may include hypoplasia of the right lung and the right pulmonary artery (not shown).

View larger version (164K): [in this window] [in a new window] [Download PPT slide]   Figure 17.  PAPVR in a 43-year-old woman with dyspnea on exertion. Volume-rendered contrast-enhanced MR angiographic image shows drainage of the left upper lobe pulmonary vein (*) into the left vertical vein (+), and eventually into the superior vena cava ().

	Quantification of Shunts

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

The first approach is based on gradient-echo cine imaging in the short-axis plane. The end-diastolic volume (EDV) and end-systolic volume (ESV) are calculated by using a stack of short-axis cine images, and the two values then are summed to obtain the stroke volume (SV), such that SV = EDV - ESV. The shunt volume is calculated as the difference between right and left ventricular stroke volumes (Table 3). This method, however, is useless for quantifying the shunt volume in ventricular septal defects, in which the left and right ventricular stroke volumes are equal. Furthermore, the presence of aortic or pulmonic valvular regurgitation may lead to inaccurate determination of stroke volume unless the regurgitation volume is subtracted from the estimated stroke volume.

View larger version (152K): [in this window] [in a new window] [Download PPT slide]   Figure 18.  Magnitude (top row) and phase (bottom row) images of the pulmonary artery (left column) and aorta (right column). Flow volume is calculated as the product of the mean flow velocity, which is measured on the phase images, and the cross-sectional area of the vessel. Flow in the pulmonary artery (PA) is equivalent to the right ventricular stroke volume (RVSV), and flow in the aorta is equivalent to the left ventricular stroke volume (LVSV).

View larger version (23K): [in this window] [in a new window] [Download PPT slide]   Figure 19.  Velocity-versus-time curves for blood flow in the aorta and the pulmonary artery (PA). Each point on the curve represents the mean blood flow in the vessel at a particular phase of the cardiac cycle, and each value is derived from a separate velocity-encoded cine MR image. Shunt severity is expressed as the ratio of pulmonary flow (Qp) to systemic flow (Qs).

	Conclusions

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

	Footnotes

 
Abbreviation: PAPVR = partial anomalous pulmonary venous return

	References

Top Abstract Introduction Supracristal Ventricular Septal... Atrioventricular Septal Defect Patent Ductus Arteriosus Aortopulmonary Window Partial Anomalous Pulmonary... Quantification of Shunts Conclusions References

 

1. Higgins CB, Byrd BF, 3rd, Farmer DW, Osaki L, Silverman NH, Cheitlin MD. Magnetic resonance imaging in patients with congenital heart disease. Circulation 1984; 70:851-860.[Medline]
2. Higgins CB, Byrd BF, 2nd, McNamara MT, et al. Magnetic resonance imaging of the heart: a review of the experience in 172 subjects. Radiology 1985; 155:671-679.[Abstract]
3. Didier D, Higgins CB, Fisher MR, Osaki L, Silverman NH, Cheitlin MD. Congenital heart disease: gated MR imaging in 72 patients. Radiology 1986; 158:227-235.[Abstract]
4. Boxt LM. MR imaging of congenital heart disease. Magn Reson Imaging Clin N Am 1996; 4:327-359.[Medline]
5. Szolar DH, Sakuma H, Higgins CB. Cardiovascular applications of magnetic resonance flow and velocity measurements. J Magn Reson Imaging 1996; 6:78-89.[Medline]
6. Mohiaddin RH, Longmore DB. Functional aspects of cardiovascular nuclear magnetic resonance imaging: techniques and application. Circulation 1993; 88:264-281.[Medline]
7. Higgins CB, Sakuma H. Heart disease: functional evaluation with MR imaging. Radiology 1996; 199:307-315.[Abstract/Free Full Text]
8. Cohen MC, Hartnell GG, Finn JP. Magnetic resonance angiography of congenital pulmonary vein anomalies. Am Heart J 1994; 127:954-955.[CrossRef][Medline]
9. Holland GA, Dougherty L, Carpenter JP, et al. Breath-hold ultrafast three-dimensional gadolinium-enhanced MR angiography of the aorta and the renal and other visceral abdominal arteries. AJR Am J Roentgenol 1996; 166:971-981.[Abstract/Free Full Text]
10. Therrien J, Webb GD. Congenital heart disease in adults. In: Braunwald E, eds. Heart disease: a textbook of cardiovascular medicine. 6th ed. Philadelphia, Pa: Saunders, 2001; 1592-1621.
11. Baron MG. Plain film diagnosis of common cardiac anomalies in the adult. Radiol Clin North Am 1999; 37:401-420.[CrossRef][Medline]
12. Kuzman WJ. Atrial septal defects in the older patient: diagnosis and treatment. Geriatrics 1967; 22:107-111.
13. Diethelm L, Dery R, Lipton MJ, Higgins CB. Atrial-level shunts: sensitivity and specificity of MR in diagnosis. Radiology 1987; 162:181-186.[Abstract]
14. Higgins CB. Radiography of congenital heart disease. In: Higgins CB, eds. Essentials of cardiac radiology and imaging. Philadelphia, Pa: Lippincott, 1992; 49-90.
15. Holmvang G, Palacios IF, Vlahakes GJ, et al. Imaging and sizing of atrial septal defects by magnetic resonance. Circulation 1995; 92:3473-3480.[Medline]
16. Hundley WG, Li HF, Lange RA, et al. Assessment of left-to-right intracardiac shunting by velocity-encoded, phase-difference magnetic resonance imaging: a comparison with oximetric and indicator dilution techniques. Circulation 1995; 91:2955-2960.[Medline]
17. Anderson RH, Lenox CC, Zuberbuhler JR. The morphology of ventricular septal defects. Perspect Pediatr Pathol 1984; 8:235-268.[Medline]
18. Funabashi N, Rubin GD. Qualitative blood flow differentiation: depiction of a left to right cardiac shunt across a ventricular septal defect using electron-beam computed tomography. Jpn Circ J 2000; 64:901-903.[CrossRef][Medline]
19. Paul JF, Mace L, Caussin C, et al. Multirow detector computed tomography assessment of intraseptal dissection and ventricular pseudoaneurysm in postinfarction ventricular septal defect. Circulation 2001; 104:497-498.[Free Full Text]
20. Didier D, Higgins CB. Identification and localization of ventricular septal defect by gated magnetic resonance imaging. Am J Cardiol 1986; 57:1363-1368.[CrossRef][Medline]
21. Bremerich J, Reddy GP, Higgins CB. MRI of supracristal ventricular septal defects. J Comput Assist Tomogr 1999; 23:13-15.[CrossRef][Medline]
22. Brenner LD, Caputo GR, Mostbeck G, et al. Quantification of left to right atrial shunts with velocity-encoded cine nuclear magnetic resonance imaging. J Am Coll Cardiol 1992; 20:1246-1250.[Abstract]
23. Parsons JM, Baker EJ, Anderson RH, et al. Morphological evaluation of atrioventricular septal defects by magnetic resonance imaging. Br Heart J 1990; 64:138-145.[Abstract/Free Full Text]
24. Studer M, Blackstone EH, Kirklin JW, et al. Determinants of early and late results of repair of atrioventricular septal (canal) defects. J Thorac Cardiovasc Surg 1982; 84:523-542.[Abstract]
25. Garver KA, Hernandez RJ, Vermilion RP, Martin Goble M. Images in cardiovascular medicine: correlative imaging of aortopulmonary window—demonstration with echocardiography, angiography, and MRI. Circulation 1997; 96:1036-1037.[Medline]
26. Incesu L, Baysal K, Kalayci AG, Erk K. Magnetic resonance imaging of proximal aortopulmonary window. Clin Imaging 1998; 22:23-25.[CrossRef][Medline]
27. Ammash NM, Seward JB, Warnes CA, Connolly HM, O’Leary PW, Danielson GK. Partial anomalous pulmonary venous connection: diagnosis by transesophageal echocardiography. J Am Coll Cardiol 1997; 29:1351-1358.[Abstract]
28. Seward J. Transesophageal echocardiography. In: Freeman W, Seward J, Khanderia B, Tajik A, eds. Transesophageal echocardiography. New York, NY: Little, Brown, 1994; 385-423.
29. Thorsen MK, Erickson SJ, Mewissen MW, Youker JE. CT and MR imaging of partial anomalous pulmonary venous return to the azygos vein. J Comput Assist Tomogr 1990; 14:1007-1009.[Medline]
30. Ferrari VA, Scott CH, Holland GA, Axel L, Sutton MS. Ultrafast three-dimensional contrast-enhanced magnetic resonance angiography and imaging in the diagnosis of partial anomalous pulmonary venous drainage. J Am Coll Cardiol 2001; 37:1120-1128.[Abstract/Free Full Text]
31. Underwood SR, Firmin DN, Klipstein RH, Rees RS, Longmore DB. Magnetic resonance velocity mapping: clinical application of a new technique. Br Heart J 1987; 57:404-412.[Abstract/Free Full Text]
32. Friedman WF, Silverman N. Congenital heart disease in infancy and childhood In: Braunwald E, ed. Heart disease: a textbook of cardiovascular medicine. 6th ed. Philadelphia: Saunders, 2001; 1505-1591.

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