Hong Y K, Park Y W, Ryu S J, Won J W, Choi J Y, Sul J H, Lee S K, Cho B K, Choe K O
Department of Diagnostic Radiology, Yonsei University, College of Medicine, Seoul, Korea.
J Comput Assist Tomogr. 2000 Sep-Oct;24(5):671-82. doi: 10.1097/00004728-200009000-00002.
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.
Twenty-two patients with visceral heterotaxy syndrome were included.
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 = 13) or left isomerism groups (n = 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 = 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 = 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.
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.
作者的目标是评估磁共振成像（MRI）与超声心动图及心导管检查相比，在评估心脏位置不明确的心脏缺陷时的诊断准确性和临床效果。
纳入22例内脏异位综合征患者。
由于根据肺动脉与支气管的关系确定的心脏位置最主要表现为向一侧偏移的趋势，因此这被视为心脏位置确定的标准参考。为本研究目的，患者被分为右位异构组（n = 13）或左位异构组（n = 9）。与超声心动图或心脏血管造影相比，MRI在检查心脏位置不明确的患者时有几个优点。（1）支气管、肺动脉和脾脏的位置可容易地确定，且差异（n = 2）可轻松评估。（2）腔静脉心房连接可得到充分成像。特别是，所有类型的完全性和部分性肺静脉异位回流均能清晰显示，无论是否涉及肺血流受限或肺静脉梗阻（n = 4）。垂直静脉的走行很容易识别，在7例完全性肺静脉异位回流的右位异构患者中，只有1例显示其位于动脉前位置。利用三维空间信息可显示肝静脉的引流模式，这对全腔静脉肺动脉连接设计很有用。（3）相关的复杂心脏异常，尤其是肺动脉的大小或外周狭窄，可得到评估，且该信息对姑息性分流手术有用。
由于MRI视野广且成像不受相关异常的限制，使用MRI可全面了解心脏位置不明确患者的心血管解剖结构，这在该复杂异常的手术矫正中具有重要价值。MRI可避免或便于对这些危重症患者进行心导管检查。
