The oblique coronal view in sonography of the retroperitoneum.

The abdominal aorta and inferior vena cava can be seen easily from the right flank on a longitudinal coronal-oblique sonogram, using the liver as an acoustic window. With this view, tortuosity of the abdominal aorta can be shown, just as it appears on frontal aortography in 70% of cases, and similar to aortography in 27% of cases. The proximal renal and common iliac arteries can be demonstrated in 73% and 82% of cases, respectively, when aneurysms are absent, and in 45% and 82% of patients when aortic aneurysms are present. Enlarged posterior abdominal lymph nodes may be detected with accuracy, sensitivity, and specificity of 90% when compared to computed tomography (CT). Prominent gonadal vessels and anomalous or duplicated venae cavae can be displayed longitudinally, just as they might appear on venography. The coronal oblique view from the right flank, and occasionally from the left flank, can be a valuable addition to the standard views obtained during abdominal sonography. It is also a valuable supplement to CT in the differentiation of paraaortic vessels from enlarged lymph nodes.