Korean J Radiol.  2006 Jun;7(2):87-96. 10.3348/kjr.2006.7.2.87.

Added Value of Coronal Reformations for Duty Radiologists and for Referring Physicians or Surgeons in the CT Diagnosis of Acute Appendicitis

• Lee KH
• Kim YH
• Hahn S
• Lee KW
• Lee HJ
• Kim TJ
• Kang SB
• Shin JH
• Park BJ

• KMID: 1782181
• DOI: http://doi.org/10.3348/kjr.2006.7.2.87

Abstract

OBJECTIVE
To assess the added value of coronal reformation for radiologists and for referring physicians or surgeons in the CT diagnosis of acute appendicitis. MATERIALS AND METHODS: Contrast-enhanced CT was performed using 16-detector-row scanners in 110 patients, 46 of whom had appendicitis. Transverse (5-mm thickness, 4-mm increment), coronal (5-mm thickness, 4-mm increment), and combined transverse and coronal sections were interpreted by four radiologists, two surgeons and two emergency physicians. The area under the receiver operating characteristic curve (Az value), sensitivity, specificity (McNemar test), diagnostic confidence and appendiceal visualization (Wilcoxon signed rank test) were compared. RESULTS: For radiologists, the additional coronal sections tended to increase the Az value (0.972 vs. 0.986, p = 0.076) and pooled sensitivity (92% [95% CI: 88, 96] vs. 96% [93, 99]), and enhanced appendiceal visualization in true-positive cases (p = 0.031). For non-radiologists, no such enhancement was observed, and the confidence for excluding acute appendicitis declined (p = 0.013). Coronal sections alone were inferior to transverse sections for diagnostic confidence as well as appendiceal visualization for each reader group studied (p < 0.05). CONCLUSION: The added value of coronal reformation is more apparent for radiologists compared to referring physicians or surgeons in the CT diagnosis of acute appendicitis.

Keyword

Appendicitis; Computed tomography (CT), image display and recording; Computed tomography (CT), image processing; Computed tomography (CT), three-dimensional; Computed tomography (CT), comparative studies

MeSH Terms

*Tomography, X-Ray Computed
Sensitivity and Specificity
Retrospective Studies
Referral and Consultation
Radiographic Image Enhancement
ROC Curve
Middle Aged
Male
Humans
Female
Appendicitis/*radiography/surgery
Aged, 80 and over
Adult
Adolescent
Acute Disease

Figure

• 

  Fig. 1 CT scans in a 53-year-old man with epigastric pain. Transverse CT scans (A, B) and coronal reformation (C, D) obtained with intravenous contrast material show the thickened appendix (arrows) and edema in cecum (arrowheads) at the orifice of the appendix. At surgery, an inflamed appendix was identified and removed. For transverse sections alone, two readers (readers 4 and 8) incorrectly excluded acute appendicitis. With additional coronal sections, CT reader 4 altered his decision to correctly diagnose acute appendicitis.

• 

  Fig. 2 CT scans in a 17-year-old woman with pain and tenderness in the right lower quadrant of abdomen and fever. Transverse CT scans (A, B) and coronal reformation (C) obtained with intravenous contrast material show the appendix (arrows) with the distal portion distended with air. Coronal reformation shows the entire length of the appendix within the coronal plane. Note the mass at the cecal wall (arrowheads) with increased attenuation of surrounding fat. At surgery, an inflamed diverticulum was identified at the cecum and the appendix was considered grossly normal. With transverse sections alone, two readers (readers 3 and 7) incorrectly diagnosed acute appendicitis. With combined transverse and coronal sections, reader 3 altered his decision to correctly exclude acute appendicitis, whereas two non-radiologists (readers 7 and 8) incorrectly diagnosed acute appendicitis. The radiologists rated possibility of diagnosis of appendicitis 32.5 (mean) and 9.7 with transverse sections alone and combined transverse and coronal sections, respectively, whereas the non-radiologists rating was 40.3 and 58.5.

• 

  Fig. 3 The box and whisker plot for the mean confidence scores of the eight CT readers for the diagnosis of acute appendicitis in true-positive cases (n = 46). White, light gray and gray boxes present transverse, coronal, and combined transverse and coronal sections, respectively. Middle lines of boxes show medians, and upper and lower box margins represent upper and lower quartiles, respectively. The ends of the vertical lines indicate the 10th and 90th percentiles. Outliers are plotted as crosses.

• 

  Fig. 4 The box and whisker plot for the mean confidence scores of the eight CT readers for the exclusion of acute appendicitis in true-negative cases (n = 64). The lower score indicates that readers were more confident at excluding acute appendicitis. White, light gray and gray boxes present transverse, coronal, and combined transverse and coronal sections, respectively. Middle lines of boxes show medians, and upper and lower box margins represent upper and lower quartiles, respectively. The ends of the vertical lines represent the 10th and 90th percentiles. Outliers are plotted as crosses.

• 

  Fig. 5 CT scans of a 32-year-old man with epigastric pain and fever. Transverse CT scan (A) and coronal reformation (B) obtained with intravenous contrast material show distended appendix (arrows), an appendicolith (arrowheads), and periappendiceal fat stranding. Coronal reformation shows the entire length of the horseshoe-shaped appendix within a coronal plane. At surgery, an inflamed appendix was identified and removed. All readers correctly diagnosed acute appendicitis in both transverse sections alone and combined transverse and coronal sections. The mean appendiceal visualization score was 87.1 and 94.3 for radiologists, and 86.1 and 88.3 for non-radiologists.

• 

  Fig. 6 The box and whisker plot for mean scores for the eight CT readers for appendiceal visualization in true-positive cases (n = 46). White, light gray and gray boxes present transverse, coronal, and combined transverse and coronal sections, respectively. Middle lines of boxes show medians, and upper and lower box margins represent upper and lower quartiles, respectively. The ends of the vertical lines indicate the 10th and 90th percentiles. Outliers are plotted as crosses.

• 

  Fig. 7 The box and whisker plot for mean scores for the eight CT readers for appendiceal visualization in true-negative cases (n = 64). White, light gray and gray boxes present transverse, coronal, and combined transverse and coronal sections, respectively. Middle lines of boxes show medians, and upper and lower box margins represent upper and lower quartiles, respectively. The end of the vertical lines shows the 10th and 90th percentiles. Outliers are plotted as crosses.

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