Correlation Between NLR and Abdominal CT and Its Predictive Value in Patients with Acute Appendicitis

Acute appendicitis (AA) is the most common cause of acute abdomen. In addition to clinical evaluation, laboratory and imaging methods are widely used in diagnosis. The neutrophil-to-lymphocyte ratio (NLR) is an easily accessible biomarker of inflammation.

This study aimed to investigate the relationship between NLR and computed tomography (CT) findings in patients with AA.

This retrospective study analyzed cases of acute appendicitis diagnosed between February 2018 and July 2023. Demographic characteristics, laboratory values, and CT findings were evaluated. Statistical analyses included correlation tests, logistic regression, and ROC curve analysis.

Of the 159 patients, 66 (41.5%) were female and 93 (58.5%) male, with a median age of 34. The mean appendiceal diameter was 10 mm. Other CT findings included periappendiceal fat stranding (97.5%), lymphadenopathy (85.5%), free fluid (34.6%), and abscess formation (5.7%). In patients with free fluid, HGB and HCT levels were significantly lower, while WBC, neutrophils, PLT, NLR, and platelet-to-lymphocyte ratio (PLR) were higher (P < 0.05). ROC analysis identified an optimal NLR cut-off value of 4.45 for predicting free fluid, with 70.9% sensitivity and 63.5% specificity.

NLR shows a significant correlation with CT findings in AA and may help predict disease severity. Particularly in centers with limited CT access, NLR may be considered a complementary parameter alongside clinical evaluation and imaging methods.