Sakakibara M, Kobayashi S, Imai H, Watanabe S, Masuda Y, Inagaki Y
Third Department of Internal Medicine, Chiba University School of Medicine.
J Cardiol. 1987 Dec;17(4):817-29.
We studied the morphological features of defects of the interatrial septum using magnetic resonance imaging (MRI) to determine the sizes of defects and other abnormalities. MR images were obtained in 28 patients with atrial septal defect, including five cases with complicated anomalies (two with Ebstein's anomaly, one pentalogy of Fallot, and one anomalous pulmonary vein connection and azygos continuation). Images were also obtained in the control subjects including seven normal volunteers and 142 patients with various acquired heart diseases. The diagnosis of atrial septal defect was established by cardiac catheterization, angiography and two-dimensional echocardiography prior to the MRI studies, and in 14 patients, the diagnosis was confirmed by surgery. The MRI unit had a superconducting magnet and operated at 0.25 or 0.50 Tesla. A spin echo pulse sequence was used with an echo time of 40 or 60 msec. At the beginning of this study, non-gated MRI images were obtained in the 28 controls and in three patients with atrial septal defect. Nongated MRI could not image the anatomical structure of the interatrial septa of 12 of the 28 controls, or any of the three patients with atrial septal defect. Nongated MRI was, therefore, inadequate for visualizing cardiac anatomy. Gated MRI images were obtained in 141 controls and in 25 patients with atrial septal defect. Gated MRI revealed the interatrial septum, interventricular septum, atrioventricular septum, mitral valve, tricuspid valve and other intracardiac structures in most subjects. In 17 control subjects (12%), however, there was a very faint signal from the central portion of the interatrial septum. In these instances, there was a gradual fading of the signal of the interatrial septum, so that they could be distinguished from the atrial septal defect. The sudden disappearance of the signal from the interatrial septum was observed by gated MRI in all 25 patients with atrial septal defect. The sizes of the defects by MRI coincided with the findings at surgery in all 14 patients. MRI showed right atrial dilatation, right ventricular hypertrophy and dilatation, and pulmonary artery dilatation in most of the patients having atrial septal defect. Complex anomalies associated with atrial septal defect were also clearly shown by MRI, such as displacement of the tricuspid leaflets in two patients with Ebstein's anomaly, and anomalous pulmonary venous connection and persistent left superior vena cava in one patient. These results indicated that gated MRI is a valuable noninvasive method of diagnosing atrial septal defect and complicating anomalies.
我们使用磁共振成像（MRI）研究了房间隔缺损的形态学特征，以确定缺损大小及其他异常情况。对28例房间隔缺损患者进行了MR图像采集，其中包括5例合并复杂畸形的病例（2例埃布斯坦畸形、1例法洛四联症、1例异常肺静脉连接及奇静脉延续）。还对包括7名正常志愿者和142例各种后天性心脏病患者的对照组进行了图像采集。在进行MRI研究之前，通过心导管检查、血管造影和二维超声心动图确立房间隔缺损的诊断，14例患者的诊断通过手术得到证实。MRI设备为超导磁体，场强为0.25或0.50特斯拉。使用自旋回波脉冲序列，回波时间为40或60毫秒。在本研究开始时，对28名对照组和3例房间隔缺损患者采集了非门控MRI图像。非门控MRI无法显示28名对照组中12例的房间隔解剖结构，也无法显示3例房间隔缺损患者中的任何一例。因此，非门控MRI不足以观察心脏解剖结构。对141名对照组和25例房间隔缺损患者采集了门控MRI图像。门控MRI在大多数受试者中显示出房间隔、室间隔、房室间隔、二尖瓣、三尖瓣及其他心内结构。然而，在17名对照组受试者（12%）中，房间隔中央部分信号非常微弱。在这些情况下，房间隔信号逐渐减弱，因此可与房间隔缺损区分开来。在所有25例房间隔缺损患者中，门控MRI均观察到房间隔信号突然消失。MRI显示的缺损大小与14例手术结果一致。MRI显示大多数房间隔缺损患者存在右心房扩张、右心室肥厚及扩张，以及肺动脉扩张。MRI还清晰显示了与房间隔缺损相关的复杂畸形，如2例埃布斯坦畸形患者的三尖瓣叶移位，以及1例患者的异常肺静脉连接和永存左上腔静脉。这些结果表明，门控MRI是诊断房间隔缺损及合并畸形的一种有价值的非侵入性方法。
