Gale M E
Radiology. 1986 Dec;161(3):635-9. doi: 10.1148/radiology.161.3.3786709.
The anterior portion of the diaphragm has three typical appearances on computed tomographic (CT) scans, depending on the cephalocaudal relation of the xiphoid to the central tendon of the diaphragm. The anterior diaphragm most often appears as a relatively smooth or slightly undulating soft-tissue curve, concave posteriorly and continuous across the midline with the lateral diaphragmatic arcs. In the next most frequent CT appearance, the diaphragmatic line is discontinuous in the midline. On each of these images, the muscular line diverges rather than converges as it approaches the anterior chest wall. Less commonly, the anterior portions of the diaphragm are imaged on CT not as a thin line but instead as a broad band with irregular, ill-defined, or angular margins. Occasionally, the anterior diaphragmatic muscle is not identified on CT because the muscle fibers are inseparable from adjacent structures, or are extremely short or even absent. An understanding of these anatomic variations permits the correct diagnosis of Morgagni hernias and explains previously described variants of plain radiographic configurations of pneumoperitoneum.
在计算机断层扫描（CT）上，膈肌前部有三种典型表现，这取决于剑突与膈肌中心腱的头尾关系。前部膈肌最常表现为相对光滑或略有起伏的软组织曲线，向后凹陷，并在中线处与外侧膈肌弓连续。在次常见的CT表现中，膈肌线在中线处不连续。在这些图像中的每一幅上，肌性线在靠近前胸壁时是分开而不是汇聚的。较少见的情况是，CT上膈肌前部不是显示为一条细线，而是显示为一条边缘不规则、界限不清或呈角状的宽带。偶尔，CT上无法识别前部膈肌肌，因为肌纤维与相邻结构无法区分，或者极其短甚至不存在。了解这些解剖变异有助于正确诊断 Morgagni 疝，并解释先前描述的气腹平片构型的变异。
