Published online before print November 13, 2002, 10.1148/radiol.2261011496
Ovoid Shape of the Vermiform Appendix: A Criterion to Exclude Acute Appendicitis—Evaluation with US1
Thomas Rettenbacher, MD,
Alois Hollerweger, MD,
Peter Macheiner, MD,
Norbert Gritzmann, MD,
Martin Daniaux, MD,
Klaus Schwamberger, MD,
Hanno Ulmer, PhD and
Dieter zur Nedden, MD
1 From the Department of Radiology II, University Hospital Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria (T.R., M.D., D.z.N.); Departments of Radiology (A.H., P.M., N.G.) and Surgery (K.S.), Hospital Barmherzige Brueder, Salzburg, Austria; and Institute of Biostatistics, University of Innsbruck, Austria (H.U.). From the 1999 RSNA scientific assembly. Received September 7, 2001; revision requested November 9; final revision received April 9, 2002; accepted April 30. Address correspondence to T.R. (e-mail: thomas.rettenbacher@uklibk.ac.at).
View larger version (153K):
[in a new window]
|
Figure 1a. Normal appendix, ovoid shape. (a) US image shows the transverse section (arrows) of the proximal portion of a normal vermiform appendix. The appendiceal cavity is empty, and the shape appears ovoid. (b) US image shows the transverse section (arrows) of the distal portion of the same appendix as in a. The appendiceal cavity contains gas, and the shape appears ovoid.
|
|
View larger version (149K):
[in a new window]
|
Figure 1b. Normal appendix, ovoid shape. (a) US image shows the transverse section (arrows) of the proximal portion of a normal vermiform appendix. The appendiceal cavity is empty, and the shape appears ovoid. (b) US image shows the transverse section (arrows) of the distal portion of the same appendix as in a. The appendiceal cavity contains gas, and the shape appears ovoid.
|
|
View larger version (174K):
[in a new window]
|
Figure 2a. Normal appendix, round shape. (a) US image shows the transverse section (arrows) of the proximal portion of a normal vermiform appendix. The appendiceal cavity is filled with feces and air, and the shape appears round. (b) US image shows the transverse section (arrows) of the distal portion of the same appendix as in a. The appendiceal cavity is filled with feces and air, and the shape appears round.
|
|
View larger version (169K):
[in a new window]
|
Figure 2b. Normal appendix, round shape. (a) US image shows the transverse section (arrows) of the proximal portion of a normal vermiform appendix. The appendiceal cavity is filled with feces and air, and the shape appears round. (b) US image shows the transverse section (arrows) of the distal portion of the same appendix as in a. The appendiceal cavity is filled with feces and air, and the shape appears round.
|
|
View larger version (180K):
[in a new window]
|
Figure 3a. Normal appendix, ovoid and round shape. (a) US image shows the ovoid transverse section (arrows and arrowheads) of the proximal portion of a normal appendix. The appendiceal cavity is empty and collapsed. Appendiceal compressibility could not be demonstrated, since the anteroposterior diameter (arrowheads) could not be decreased. (b) US image shows the longitudinal section (arrows) of the proximal portion, which is located between the abdominal wall and the psoas muscle, in the same appendix as in a. (c) US image shows the longitudinal section (straight arrows) of the distal portion, which extends over the iliac artery (curved arrows) into the true pelvis, in the same appendix as in a. (d) US image shows the transverse section (black arrows) of the distal portion, which is located in the true pelvis, in the same appendix as in a. That part of the appendix is filled with fluid and is round. Compressibility could not be demonstrated because the appendix could not be compressed against a fixed anatomic structure. White arrow indicates the right iliac artery.
|
|
View larger version (158K):
[in a new window]
|
Figure 3b. Normal appendix, ovoid and round shape. (a) US image shows the ovoid transverse section (arrows and arrowheads) of the proximal portion of a normal appendix. The appendiceal cavity is empty and collapsed. Appendiceal compressibility could not be demonstrated, since the anteroposterior diameter (arrowheads) could not be decreased. (b) US image shows the longitudinal section (arrows) of the proximal portion, which is located between the abdominal wall and the psoas muscle, in the same appendix as in a. (c) US image shows the longitudinal section (straight arrows) of the distal portion, which extends over the iliac artery (curved arrows) into the true pelvis, in the same appendix as in a. (d) US image shows the transverse section (black arrows) of the distal portion, which is located in the true pelvis, in the same appendix as in a. That part of the appendix is filled with fluid and is round. Compressibility could not be demonstrated because the appendix could not be compressed against a fixed anatomic structure. White arrow indicates the right iliac artery.
|
|
View larger version (173K):
[in a new window]
|
Figure 3c. Normal appendix, ovoid and round shape. (a) US image shows the ovoid transverse section (arrows and arrowheads) of the proximal portion of a normal appendix. The appendiceal cavity is empty and collapsed. Appendiceal compressibility could not be demonstrated, since the anteroposterior diameter (arrowheads) could not be decreased. (b) US image shows the longitudinal section (arrows) of the proximal portion, which is located between the abdominal wall and the psoas muscle, in the same appendix as in a. (c) US image shows the longitudinal section (straight arrows) of the distal portion, which extends over the iliac artery (curved arrows) into the true pelvis, in the same appendix as in a. (d) US image shows the transverse section (black arrows) of the distal portion, which is located in the true pelvis, in the same appendix as in a. That part of the appendix is filled with fluid and is round. Compressibility could not be demonstrated because the appendix could not be compressed against a fixed anatomic structure. White arrow indicates the right iliac artery.
|
|
View larger version (178K):
[in a new window]
|
Figure 3d. Normal appendix, ovoid and round shape. (a) US image shows the ovoid transverse section (arrows and arrowheads) of the proximal portion of a normal appendix. The appendiceal cavity is empty and collapsed. Appendiceal compressibility could not be demonstrated, since the anteroposterior diameter (arrowheads) could not be decreased. (b) US image shows the longitudinal section (arrows) of the proximal portion, which is located between the abdominal wall and the psoas muscle, in the same appendix as in a. (c) US image shows the longitudinal section (straight arrows) of the distal portion, which extends over the iliac artery (curved arrows) into the true pelvis, in the same appendix as in a. (d) US image shows the transverse section (black arrows) of the distal portion, which is located in the true pelvis, in the same appendix as in a. That part of the appendix is filled with fluid and is round. Compressibility could not be demonstrated because the appendix could not be compressed against a fixed anatomic structure. White arrow indicates the right iliac artery.
|
|
View larger version (180K):
[in a new window]
|
Figure 4. Acute appendicitis, round shape. US image shows the transverse section (arrowheads) of an acutely inflamed appendix that appears round.
|
|
View larger version (59K):
[in a new window]
|
Figure 5. Graph illustrates the proportion of appendiceal shapes. Horizontally striped areas are for appendices that are ovoid over their entire length. Diagonally striped areas are for appendices that are partly ovoid and partly round. White areas are for appendices that are round over their entire length. Column A represents 100 control subjects; column B, 174 patients with clinical suspicion of acute appendicitis without having acute appendicitis; and column C, 108 patients with acute appendicitis. Each patient group is 100%.
|
|
Copyright © 2003 by the Radiological Society of North America.
