Nowadays, we need to counterbalance the excellent diagnostic yield of the abdominal CT Scan, with the significant risks of X irradiation. The Low Dose CT Scan allows confirmation of a diagnosis of appendicitis or nephrolithiasis with comparable precision and a much lower irradiation dose. In the case of appendicitis, the ultrasound is particularly useful, provided that the patient's BMI is <30. If there is suspicion of diverticulitis, the standard CT Scan remains the first line test. The Ultrasound is the first choice exam for a woman in childbearing age presenting with an acute abdominal pain.