Efficacy of MRI in Complicated Congenital Heart Disease with Visceral Heterotaxy Syndrome

Abstract

Purpose:The authors' goal was to assess the diagnostic accuracy and clinical effect of MRI compared with echocardiography and catheterization in the evaluation of cardiac defects with situs ambiguous.Method: Twenty-two patients with visceral heterotaxy syndrome were included. Results: Because situs determined by the relation between the pulmonary artery and bronchi showed most predominantly a tendency toward lateralization, this was regarded as the standard reference of situs determination. For the purpose of this study, patients were classified as having right isomerism (n ‫ס‬ 13) or left isomerism groups (n ‫ס‬ 9). MRI has several advantages compared with echocardiography or cardiac angiography for examining patients with situs ambiguous. (1) The bronchial, pulmonary arterial, and splenic situs can be readily determined, and discrepancies (n ‫ס‬ 2) can be assessed easily. (2) Venoatrial connections are adequately imaged. In particular, all types of total and partial anomalous pulmonary venous return are delineated, regardless of whether restrictions of pulmonary blood flow or pulmonary venous obstructions are involved (n ‫ס‬ 4). The courses of vertical veins were easily identified, and the prearterial position was revealed in only one of seven right isomerisms with total anomalous pulmonary venous return. The drain pattern of the hepatic vein can be visualized using three-dimensional spatial information and is useful for total cavopulmonary connection design. (3) Associated complicated cardiac anomalies, particularly the size or peripheral stenosis of the pulmonary arteries, may be evaluated, and this information is useful for palliative shunt operations.Conclusion: Because of its wide field of view and imaging, which is not restricted by associated anomalies, a thorough understanding of the cardiovascular anatomy of the situs ambiguous can be achieved using MRI, which is of considerable value in the surgical correction of this complicated anomaly. MRI can obviate or facilitate catheterization in these critically ill patients.

Isolated Left Thoracic Isomerism with Lung Cancer: Report of a Case

“…We performed pulmonary angiography to investigate the vascular anatomy, although magnetic resonance imaging has also been reported to be useful, and it eliminates the need for invasive catheterization in complicated anatomy. 9 It is important to clarify the anatomy in situs ambiguus before surgical manipulation, especially before hilar lymph node dissection.…”

The Role of Cardiovascular Magnetic Resonance in Pediatric Congenital Heart Disease

“…Isomerism of the right atrial appendages is associated with bilateral right bronchi and tri-lobed lungs, bilateral right atrial appendages, asplenia and midline liver. The left atrial isomerism is associated with bilateral left bronchi; bi-lobed lung, bilateral left atrial appendages, polysplenia and interrupted IVC [114,115]. …”

CT of Congenital Heart Disease: Normal Anatomy and Typical Pathologic Conditions

“…Isomerism.-Although the atrial situs is identified on the basis of the morphology of the atrial appendage, characterization of the latter based on laterality is very difficult (20,27,28,36). The bronchial branching pattern is generally used to confirm the atrial situs because it almost always corresponds to the atrial situs.…”

“…Left Atrial Isomerism.-In left isomerism, bilateral atria have a finger-like appendage with a narrow opening characterizing the morphologic left atrial appendage (Fig 28a) (20,27,28,36), both main bronchi are symmetrically long, and the upper lobe bronchi are bilaterally hyparterial (Fig 28b). In addition, interruption of the IVC with azygos-hemiazygos vein continuity frequently accompanies left isomerism and is highly specific for this condition (Fig 28c).…”