The prevalence and patterns of intraluminal air in acute appendicitis at CT
ABSTRACT The purpose of this study is to investigate if the presence and distribution of intraluminal air in the appendix contributes to the computed tomography (CT) diagnosis of appendicitis. We identified 100 consecutive patients (57 men and 43 women; mean age, 38) with CT prior to appendectomy for acute appendicitis over a 5-year period and a control group of 100 consecutive patients (29 men and 71 women; mean age, 39) who underwent CT for acute abdominal pain without appendicitis. Patients were scanned using multidetector row CT scanners at 1.25 or 5-mm slice thickness, peak tube voltage of 120 kVp, and milliamperse automatically adjusted to attain a noise index of 12. Ninety-two of 100 study patients and 95 of 100 controls received 150 mL intravenous contrast. Two independent readers noted the presence and distribution pattern of intraluminal air in the appendix, appendiceal diameter, wall hyperemia, wall thickening (>3 mm), and wall stratification and presence of any secondary signs of appendicitis including fat stranding and free fluid. Data were compared between groups using Fisher's exact test and Student's t test. Intraluminal air in the appendix was more common in control patients versus patients with appendicitis (66 of 100 versus 27 of 100, p < 0.001). No significant differences in the patterns of intraluminal air were found between cases and controls. Among appendicitis cases, there was no significant difference in mean appendiceal diameter (12.8 versus 12.0, p = 0.20) or number of CT signs of appendicitis (1.93 versus 1.86, p = 0.78) in cases with intraluminal air versus without. No case of appendicitis demonstrated intraluminal air without secondary signs of appendicitis. Although intraluminal air is sometimes assumed to exclude a diagnosis of appendicitis, it is actually a common finding seen in up to 27 % of cases at CT. The pattern of intraluminal air was not helpful in differentiating a normal appendix from appendicitis.
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ABSTRACT: The aim of the present study was to investigate the significance of appendicoliths as an exacerbating factor of acute appendicitis using multivariate analysis. A total of 254 patients with pathologically proved acute appendicitis were enrolled in this retrospective study (male, 51 %; mean age, 40.1 years; range, 15-91 years). Two radiologists performed a consensus evaluation of preoperative CT images for the presence of appendicoliths in consensus. When there were appendicoliths, they assessed the number and location of appendicoliths, and measured the longest diameter of the largest appendicolith. Pathological diagnosis was used for the reference standard. The relationships of appendicoliths to gangrenous appendicitis and to perforated appendicitis were each assessed with multiple logistic regression models, which were adjusted for demographic and clinical characteristics of patients. Significant relationships were identified between gangrenous appendicitis and the presence of appendicoliths (OR, 2.2; 95 % CI, 1.2-4.0), the largest appendicolith more than 5 mm in the longest (OR, 3.0; 95 % CI, 1.6-5.7), and location of an appendicolith at the root of the appendix (OR, 2.0; 95 % CI, 1.1-3.8). Among the CT characteristics, the location of an appendicolith at the root of the appendix only showed significant relationship with perforated appendicitis (OR, 4.5; 95 % CI, 1.4-15.4). Size of the largest appendicolith and location of appendicoliths at the root of the appendix are exacerbating factors of acute appendicitis.Emergency Radiology 11/2012; 20(2). DOI:10.1007/s10140-012-1093-5
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ABSTRACT: While acute appendicitis is a common and important clinical problem, a variety of other disease processes can affect the appendix. Simple and perforated appendicitis, tip appendicitis, and stump appendicitis share a common clinical presentation including anorexia, right lower quadrant pain, and fever. By imaging, most cases of acute appendicitis exhibit luminal dilation, wall thickening, and periappendiceal inflammatory stranding. In tip appendicitis, these changes are isolated to the distal appendix, often with an obstructing appendicolith. Perforated appendicitis can exhibit mural discontinuity, periappendiceal abscess, and/or extraluminal appendicoliths. After appendectomy, the appendiceal remnant or "stump" can become inflamed, often necessitating repeat surgery. Inflammatory bowel disease can involve the terminal ileum, secondarily involving the appendix, or may primarily involve the appendix. Patient symptoms can be chronic in such cases, and mucosal hyperenhancement is a pronounced imaging feature. In asymptomatic patients without appendiceal inflammation, the appendix can be dilated by intraluminal material such as inspissated succus in cystic fibrosis or mucus from benign appendiceal mucocele. Finally, neoplasms such as typical appendiceal carcinoid tumor and mucinous adenocarcinoma can involve the appendix. Carcinoids are often small and incidentally discovered at pathologic examination, while malignant mucinous adenocarcinoma tends to present with advanced disease including pseudomyxoma peritonei. Cecal cancers can also obstruct the appendiceal lumen and cause acute appendicitis; an astute radiologist can recognize this prospectively and facilitate definitive resection (right hemicolectomy) at the time of surgery. Attention to mural features, cecal configuration, and periappendiceal inflammation is essential to the correct prospective diagnosis of complicated appendicitis and less common appendiceal pathologies.Emergency Radiology 01/2014; 21(5). DOI:10.1007/s10140-013-1188-7
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ABSTRACT: Confident diagnosis of appendicitis when the appendix is borderline (6 to 7 mm) in size can be challenging. This retrospective study assessed computed tomography (CT) findings that are most predictive of appendicitis when the appendix is borderline in diameter. Three radiologists conducted separate, blind retrospective reviews of 105 contrast-enhanced CTs with borderline appendices. Presence or absence of appendicitis was confirmed by chart review of clinical or surgical outcomes. Logistic regression was used to determine the odds ratio (OR) and the receiver operating characteristic for CT features predictive of appendicitis. Absence of intraluminal air (OR = 5.11, p < 0.001), wall hyperemia (OR = 3.92, p = 0.002), wall thickening (OR = 29.7, p < 0.001), and fat stranding (OR = 3.85, p = 0.003) were significant findings in univariate logistic regression. Using a multivariate model, we found that the absence of intraluminal air (OR = 6.04, p = 0.002) and wall thickening (OR = 24.6, p < 0.001) remained statistically significant and were unaffected by adjustment for gender and pediatric age. The area under the curve was significantly greater for the multivariate model than the initial, clinical CT impressions (p = 0.024). The combination of wall thickening and absence of intraluminal air was 92.6 % (95 % CI 75.7-99.1) sensitive and 82.4 % (95 % CI 65.5-93.2) specific for appendicitis. Wall thickening and the absence of intraluminal air are prominent predictors of appendicitis and, if present together, these features may aid in identifying appendicitis on CT when the appendix is borderline in size.Emergency Radiology 02/2015; 22(4). DOI:10.1007/s10140-015-1297-6