Diagnostic imaging is a constantly evolving specialty with new technology and new imaging methods constantly arising. It can be extremely challenging to navigate the ever-changing tide of medical imaging. Clinicians are continually plagued by a variety of questions when requesting imaging studies.

1. “What study is best to evaluate right upper quadrant pain?”

2. “Does the CT require IV contrast?”

3. “Can the patient eat before the upper GI?”

4. “What information will I get from the CT versus the ultrasound?”

These and other questions can make it difficult for the referring clinician to request the most appropriate investigation and to counsel the patient on the required preparation for the examination. It is the intention of this text to guide clinicians through the maze of medical imaging by providing information on different imaging modalities (e.g., x-ray, fluoroscopy, ultrasound, CT, MR, nuclear imaging, interventional procedure). Consideration will be given to general information about the technique, how the procedure is performed, patient preparation, contraindications to the examination, and limitations of the studies.

The text is divided into imaging by body region and technology (e.g., body MR imaging, neuroradiology, genitourinary imaging, and so on). Charts are provided for some of the more common imaging requests.

Clearly, given the scope of diagnostic imaging and the rapidity with which it changes, it is not possible to be exhaustive in the discussions of each type of study or modality. Some topics are beyond the scope of the text and are not included for discussion.