Sensitivity , specificity and predictive values of ultrasonography in the diagnosis of acute appendicitis

الملخص EN

objective: To evaluate the sensitivity and specificity, negative predictive value (NPV), and positive predictive value (PPV)of ultrasonography (US) in the diagnosis of acute appendicitis.

PATIENTS AND METHODS A cross sectional study of 125 patients with suspected appendicitis was performed ..

The appendiceal diameter (normal, less than 6 mm), compressibility of the appendix ,intraluminal fluid and echogenicity of surrounding fat were the primary criteria used to determine the status of the appendix by ultrasound and compare with histopathological examination as confirmative test RESULTS: The prevalence of real confirmed appendicitis by histopathology examination is 46% .while the sensitivity of sonographic examination in detecting appendicitis is 85%, the specificity is 53%, .

The positive predictive value of sonography is 60 %; while the negative predictive value is 81%.The most accurate appendiceal finding for appendicitis was a diameter of 6 mm or larger 95% while 81% of confirmed cases have lack compressibility while only 28% of confirmed cases of true appendicitis have intraluminal fluid .

CONCLUSION: Sonography is useful in detecting acute appendicitis and can clearly show the abnormal appendix more frequently .with high sensitivity and low specificity