Analysis of CT characteristics in the diagnosis of Schistosoma japonicum associated appendicitis with clinical and pathological correlation: a diagnostic accuracy study

Abstract

Purpose To clarify unique non-contrast CT (NCCT) characteristics for early recognition of Schistosomal associated appendicitis (SAA) differentiating from Non-schistosomal associated appendicitis (NSA). Material and methods Clinical and pathological data of 50 cases with SAA and 60 cases with NSA who underwent emergency appendectomy were retrospectively compared to pre-surgical NCCT features such as direct and indirect signs of acute appendicitis as well as appendicoliths, colon calcifications as diagnostic criteria. Statistical methods such as Chi-square (χ 2), t-tests, Principal component analysis (PCA), Binary Logistic regression (LR) and Factor Analysis (FA) were utilized to observe differences and isolate recognizable CT features of SAA. Pre and post hoc diagnostic performance of all criteria was calculated as sensitivity, specificity, and the Odds Ratio (OR). Results Age > 50 years, diameter > 13 mm, pneumatosis, peri appendiceal abscess, focal wall defect, perforation; Orbital, linear and point types of appendicular wall calcifications; sigmoid colon and cecal curvilinear calcifications were observed as unique characteristics with a sensitivity of 84-95% and specificity of 91-98% in predicting SAA by OR of 6.2 times. Pre and post hoc hypothetical analysis did not show any significance for all other factors. Conclusion Factors such as elderly age, CT features such as larger appendicular diameter, appendicular wall calcifications along with sigmoid colon, and cecal calcifications, signs of perforation or abscess are characteristic for early recognition of SAA. Keywords Schistosoma japonicum • Intestinal Schistosomiasis • Multislice computed tomography • curvilinear calcifications • Peri appendiceal abscess Abbreviations AIR score Appendicitis inflammatory response score SAA Schistosomal associated acute appendicitis Bimbadhar Valluru, Zhou Zhou contributed equally to this work.

Medical Imaging in the Diagnosis of Schistosomiasis: A Review

“…The same findings were reported in a study from Valluru et al as well, in which 50 patients with schistosomal associated appendicitis were evaluated with CT scan: these subjects presented mainly appendiceal wall-thickening and calcifications along colon wall in multiple sites, especially in the sigmoid colon and rectum [ 36 ].…”

Appendiceal Schistosomiasis Presenting as an Appendiceal Mass

“…The current diagnostic methods for the diagnosis of schistosomiasis and schistosoma acute appendicitis include the use of microbiologic tests like stool or urine microscopy, haemtological tests like complete blood count, pathological studies like PCR, ELISA, indirect haemagglutination or immunofluorescence assays and anti-schistosomal antibodies as well as special imaging modalities like contrast or non-contrast abdominal CT scan and histologic examination of rectal or bladder biopsy specimens. [ 6 7 20 21 22 ] The response of the index case to initial non-operative management suggests that schistosomal appendicitis masses respond to initial non-operative management providing opportunity for interval appendicectomy at a later date.…”

Foresight in the diagnosis of trematodiasis: innovations versus routine methods

“…Значительное внимание уделяется технологиям визуализации в диагностики гельминтозов [90]. В одном из исследований изучали случаи аппендицитов, связанные с шистосомозом [91]. В результате были определены особенности данных компьютерной томографии, которые могут являться критериями раннего распознавания S. japonicum -большой диаметр, кальцификаты стенки аппендикса вместе с сигмовидной кишкой и кальцификаты слепой кишки, признаки перфорации или абсцесса.…”