Echographic appearance of the right hemidiaphragm.

Abstract

In a prospective evaluation of the right upper quadrant in 100 consecutive healthy subjects, three echogenic lines were visualized in the right posterior, superior, and lateral aspects of the abdomen in the region of the right hemidiaphragm in approximately 80 per cent. A retrospective review was made of the sonograms of 33 patients with right pleural effusions alone, 14 patients with ascites alone, and ten patients with combined ascites and pleural effusions. Analysis of the number of echo genic lines seen in the region of the right hemidiaphragm and their relationship to the gas reverberation artifact suggests that two of the three lines seen in scans of normal subjects represent actual structures {diaphragm-liver capsule complex and lung-visceral pleura complex), whereas the third, superior, line is a mirror-image artifact. Scans of an in-vitro model constmcted to simulate the liver, diaphragm, lung, and pleural effusion support the hypothesis that the lung and not the diaphragm is the mirror of the right upper quadrant. (Key words: diaphragm; pleural effusion; ascites; mirror image artifact) Although the diaphragm is seen in almost every abdominal sonogram, very little has been written about its sonographic appearance. It is generally assumed that the diaphragm is a curvilinear reflection above the liver. Weill states that the dome of the diaphrab'Ill cannot be distinguished from the superior aspect of the liver, and that separation of these stmctures is indicative of ascites.• With the acquisition of the latest generation of real-time sector scanners, it became apparent that three echogenic lines can usually be seen in the right upper quadrant, particularly during deep inspiration. We thus undertook a study to identifY the origin of these echoes.

An evaluation of diaphragmatic movements in hemiplegic patients

“…The Mmode is convenient for measurements, as the beginning and end of each breath can be seen easily [4]. Some authors described the diaphragm as three echogenic lines and others as two echogenic lines [18,19]. In our study, the diaphragm was seen as one echogenic line, similar to Gerscovich et al [7], and we did not encounter any technical difficulties obtaining ultrasonographic images of the diaphragm [20].…”

Ultrasonographic evaluation of diaphragmatic motion.

“…The sonographic appearance of the diaphragm has been described by some authors as 3 echogenic lines, of which the caudal line represents the diaphragm-liver complex, the middle line represents the lung-visceral pleura complex, and the rostral line results from a mirror image artifact. 13 Other authors have described the diaphragm as 2 echogenic layers (peritoneum and pleura) sandwiching a hypoechoic line (the muscle itself). 14 We did not recognize the reported different layers.…”

Neuromuscular ultrasound for evaluation of the diaphragm

“…28 The diaphragm can be seen as 2 echogenic layers 29 of peritoneum and pleura sandwiching a more hypoechoic line of the muscle itself (Figure 2). 13, 18, 30, 31 It thickens during inspiration, unless it is severely atrophic. An atrophic diaphragm will appear as a very thin strip deep to the intercostal muscles, and it may not move with inspiration.…”