Published online before print June 20, 2003, 10.1148/radiol.2282011554
(Radiology 2003;228:389.)
A more recent version of this article appeared on August 1, 2003
Right Hemidiaphragmatic Mobility: Assessment with US Measurement of Craniocaudal Displacement of Left Branches of Portal Vein1
Nair S. G. Toledo, PT,
Sérgio K. Kodaira, MD, PhD,
Paulo C. B. Massarollo, MD, PhD,
Osvaldo I. Pereira, MD, PhD and
Sérgio Mies, MD, PhD
1 From the Liver Unit (N.S.G.T., P.C.B.M., O.I.P., S.M.) and Department of Radiology (S.K.K.), University of São Paulo Medical School, Brazil. Received September 19, 2001; revision requested November 26; final revision received November 25, 2002; accepted December 19. Supported by FAPESP grant 99/10418-3. Address correspondence to N.S.G.T., R. Luxemburgo, 113-CEP, 86046-410 Londrina, Brazil (e-mail: tolecosta@hotmail.com).
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Figure 1. Drawings of the scanning plane used for B-mode US measurement of craniocaudal displacement of the left intrahepatic branch of the portal vein (LBPV). The transducer was placed in a right subcostal position with longitudinal orientation. Vertical arrows show the direction of the ultrasound beam. A, Lateral view. The ultrasound beam was directed perpendicularly to the craniocaudal axis during all phases of respiration. B, Transverse view. The liver was scanned in a sagittal plane, which included the retrohepatic portion of the inferior vena cava (IVC). With this angle of incidence, the left branch of the portal vein usually was identified in the field of view.
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Figure 2. B-mode US measurement of craniocaudal displacement of the left intrahepatic portal vein branch (arrow). The liver was scanned in a sagittal plane, which included the retrohepatic portion of the inferior vena cava. The P cursor marks the initial position of this vessel during forced expiration, and another cursor marks the position of the vessel during forced inspiration. The craniocaudal displacement of these points, measured from cursor to cursor, was recorded in millimeters.
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Figure 3. Linear regression curve between US measurement of craniocaudal displacement of the intrahepatic portal vein branches and radiographic measurement of right hemidiaphragmatic mobility. There was a positive linear correlation between the two measurements: hemidiaphragmatic mobility = (-1.562 + 1.032) x portal vein branch displacement (r = 0.651, P < .001).
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Figure 4. Differences between US and radiographic measurements in each patient plotted against means. The limits of agreement correspond to the top and bottom lines and were calculated by adding and subtracting 2 SDs from the mean difference. These extreme values define the range within which 95% of the differences between the two measurement methods are expected to lie.
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Figure 5. Differences between repeated radiographic measurements of right hemidiaphragmatic mobility plotted against means. If the initial and final measurements in each case were the same, all points would lie on the line corresponding to the mean difference. However, the points show considerable variation in repeated measurements performed in the same subjects, and this variation indicates poor repeatability.
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Figure 6. Differences between repeated US measurements of craniocaudal displacement of the intrahepatic portal vein branches plotted against means. The points are closer to the mean difference line compared with the points in Figure 5 and thus indicate better repeatability with the US method.
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Copyright © 2003 by the Radiological Society of North America.
