Right hemidiaphragmatic mobility: assessment with US measurement of craniocaudal displacement of left branches of portal vein.

Objective: To evaluate the correlation and agreement between ultrasonographic (US) measurement of craniocaudal displacement of the left intrahepatic branches of the portal vein and radiographic measurement of right hemidiaphragmatic mobility.

Methods: Fifty-one patients with indications for abdominal angiography or percutaneous cholangiography prospectively underwent radiographic evaluation of right hemidiaphragmatic mobility and B-mode US measurement of craniocaudal displacement of the left intrahepatic branches of the portal vein. US was performed by using a 3.5-MHz convex transducer in a right subcostal position with a longitudinal orientation. Statistical analyses were performed by using linear regression, paired Student t test, and Bland-Altman analyses.

Results: The correlation between the US and radiographic measurements was found to be linear: hemidiaphragmatic mobility = (-1.562 + 1.032) x portal vein branch displacement (r = 0.651, P <.001). The mean craniocaudal displacement of the intrahepatic branches of the portal vein measured at US was 35.2 mm +/- 10.7 (SD). The mean right hemidiaphragmatic mobility measured at radiography was 34.8 mm +/- 17.0. The mean difference between the two measurements was not statistically significant (0.4 mm +/- 12.9, P =.807).

Conclusions: US measurement of craniocaudal displacement of the left intrahepatic branches of the portal vein can be used for indirect assessment of right hemidiaphragmatic mobility.