Weight-adjusted low-dose contrast media paired with low-radiation dose abdomen CT

The investigators are aiming for a 10% reduction in iodine dosage at 10 kVp reduction in CT radiation. Routine iodine dosing is 0.521 g I/kg at 120 kVp. Therefore, at 90 kVp, a 30% reduction in iodine dosing is expected, which is 0.365 g I/kg. At 100 kVp, the iodine dosage is reduced to 0.417 g I/kg, which is a 20% reduction. The kVp value is automatically selected by the CT device according to the body habitus, which is a clinical routine.

The primary outcome of the study is the diagnostic accuracy of double low-dose CT for acute appendicitis in young adults with suspected acute appendicitis. Based on the CT findings, a three-tiered diagnosis of appendicitis will be given (no appendicitis, uncomplicated appendicitis, or complicated appendicitis). In the case of no appendicitis, a possible alternative diagnosis is given. The reference standard for appendicitis is operative findings and surgical pathology reports. In nonoperative cases, sequential radiologic evaluation, clinical follow-up, and the judgment of the attending physician will conclude the diagnosis. Specifically, if the patient is not treated for recurrent symptoms within 6 months, the radiologic diagnosis of CT findings is considered valid. The diagnostic accuracy for acute appendicitis is true positive for acute appendicitis and true negative for acute appendicitis divided by all participants.