The American College of Radiology (ACR) has developed appropriateness criteria that recommend modalities for various clinical problems.
When to Order Contrast-Enhanced CT: http://www.aafp.org/afp/2013/0901/p312.html
| suspected Aortic Dissection | The ACR recommends CT with contrast as the definitive test, and a radiograph as the initial test if it does not delay definitive testing. MR angiography is recommended as an alternative to CT if CT is contraindicated or unavailable. |
| Head Trauma | Imaging recommendations for head trauma are broken down into various types, but CT is recommended in most cases, and other imaging may also be recommended based on the type of injury and age of the patient. |
| Chronic Back Neck Pain | For chronic neck pain, a cervical spine radiograph is recommended. |
| Persistent Sinusitis in children | The ACR considers CT to be the gold standard for evaluating persistent sinusitis in children, as it accurately shows soft-tissue structures. |
| Suspected Ankle fracture | Radiography is the preferred imaging, assuming the patient meets the Ottawa ankle criteria. |
References:
American College of Radiology: ACR appropriateness criteria.”
http://www.acr.org/Quality-Safety/Appropriateness-Criteria