Abstract
Purpose
The aim of this study was to identify the factors that prevent the visualization of
a normal appendix by 64-slice MDCT.
Materials and methods
Thirty-nine consecutive patients with a normal appendix not visualized during routine
abdominal CT and without a history of abdominal surgery were selected for this study.
In addition, 100 consecutive patients with a clearly visualized normal appendix by
CT were selected as controls. Two radiologists, by consensus, evaluated MDCT images
for cecum level, pericecal fat content, presence of small bowel dilatation, presence
of pericecal fluid, presence of cecal wall thickening, and identification of the ileocecal
valve.
Results
Patients with a nonvisualized normal appendix had a significantly lower cecum level,
minimal pericecal fat, and a higher amount of pericecal fluid and were less likely
to have an identified ileocecal valve (46.2%, 79.5%, 17.9%, and 76.9%, respectively)
than patients with a clearly visualized appendix (18%, 9%, 4%, and 100%, respectively)
(all P<.01). The presence of small bowel dilatation and cecal wall thickening was not statistically
significant (7.7% vs. 8% and 7.7% vs. 9%, respectively) (all P>.01).
Conclusion
The factors that influence the nonvisualization of a normal appendix on MDCT images
are as follows: a low cecum level, minimal pericecal fat, presence of pericecal fluid,
and nonidentification of the ileocecal valve.
Keywords
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References
- Helical CT technique for the diagnosis of appendicitis: prospective evaluation of a focused appendix CT examination.Radiology. 1997; 202: 139-144
- Appendicitis at the millennium.Radiology. 2000; 215: 337-348
- MDCT of patients with acute abdominal pain: a new perspective using coronal reformations from submillimeter isotropic voxels.AJR Am J Roentgenol. 2004; 183: 899-906
- The nonvisualized appendix: incidence of acute appendicitis when secondary inflammatory changes are absent.AJR Am J Roentgenol. 2004; 183: 889-892
- Frequency of visualization and thickness of normal appendix at nonenhanced helical CT.Radiology. 2002; 225: 400-406
- Visualization rate and pattern of normal appendix on multidetector computed tomography by using multiplanar reformation display.J Comput Assist Tomogr. 2005; 29: 446-451
- Right lower quadrant pain: value of the nonvisualized appendix in patients at multidetector CT.Radiology. 2006; 241: 175-180
- CT demonstration of the appendix in asymptomatic adults.Gastrointest Radiol. 1989; 14: 271-273
- CT of the normal appendix.J Comput Assist Tomogr. 1991; 15: 575-577
- CT appearance of the normal appendix in adults.Eur Radiol. 2005; 15: 2096-2103
- Multidetector-row CT of the appendix in healthy adults.Emerg Radiol. 2006; 12: 248-253
- Computed tomography evaluation of the normal appendix: comparison of low-dose and standard-dose unenhanced helical computed tomography.J Comput Assist Tomogr. 2007; 31: 732-740
- Efficacy of CT in distinguishing small-bowel obstruction from other causes of small-bowel dilatation.AJR Am J Roentgenol. 1994; 162: 43-47
- Appendix and cecum. Embryology, anatomy, and surgical applications.Surg Clin North Am. 2000; 80: 295-318
- Pitfalls in the CT diagnosis of appendicitis.Br J Radiol. 2004; 77: 792-799
- Appendiceal CT in pediatric patients: relationship of visualization to amount of peritoneal fat.AJR Am J Roentgenol. 2001; 176: 497-500
- Why we miss the diagnosis of appendicitis on abdominal CT: evaluation of imaging features of appendicitis incorrectly diagnosed on CT.AJR Am J Roentgenol. 2005; 184: 855-859
- Diagnosis of acute appendicitis: value of unenhanced CT.AJR Am J Roentgenol. 1993; 160: 763-766
- CT evaluation of the colon: inflammatory disease.Radiographics. 2000; 20: 399-418
- Agenesis of the vermiform appendix.Surg Laparosc Endosc Percutan Tech. 2000; 10: 110-112
- Prospective comparison of helical CT of the abdomen and pelvis without and with oral contrast in assessing acute abdominal pain in adult Emergency Department patients.Emerg Radiol. 2006; 12: 150-157
- Rapid CT diagnosis of acute appendicitis with IV contrast material.Emerg Radiol. 2006; 12: 99-102
Article info
Publication history
Published online: August 11, 2008
Accepted:
June 10,
2008
Received:
March 1,
2008
Identification
Copyright
© 2009 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
