Diagnostic value of CT compared to ultrasound in the evaluation of acute abdominal pain in children younger than 10 years old.

To assess the diagnostic value of ultrasound compared to CT in evaluating acute abdominal pain of different causes in children 10 years of age and under, hospital records and imaging files of 4052 patients under age of 10 who had imaging for abdominal pain were reviewed. One-hundred-thirty-two patients (3 %), (74 males/58 females) who underwent ultrasound and CT within 24 h were divided by age: group I, ages 0-48 months (25 patients); group II, 49-84 months (53 patients); and group III, 85-120 months (54 patients). Diagnoses at ultrasound, CT, and discharge were compared. Cases of a change in diagnosis following CT and impact of the changed diagnosis on patient management were assessed. Non-diagnostic ultrasound or a diagnostic conundrum was present in a small percentage (3 %) of our patients. In the group of patients imaged with two modalities, CT changed the diagnosis in 73/132 patients (55.3 %). Patient management changed in 63/132 patients (47.7 %). CT changed the diagnosis in 46/64 patients with surgical conditions (71.8 %, p < 0.001). Among patients with surgical conditions, the difference between ultrasonography (US) and CT diagnoses was significant in groups 2 (p = 0.046) and 3 (p =  .001). The impact of the change in diagnosis in surgical patients imaged with two modalities was significant in the group as a whole and in each age group separately. Non-diagnostic or equivocal US in a small percentage of patients is probably sufficient to justify the additional radiation burden.