dear Indunil Karunarathna , Choosing which imaging test to use depends on the specific medical situation, the patient's condition, and what resources are available.
Each imaging modality has its strengths and specific applications in diagnosing acute abdomen. Ultrasound is excellent for real-time and safe evaluation of gallbladder, pelvic organs, and fluid collections. CT scan offers detailed and comprehensive imaging for a wide range of abdominal pathologies with high accuracy. X-ray serves as a quick, initial screening tool but is limited in its diagnostic scope.