In this article, the authors describe a simple classification system for defining different types of additional imaging exams. Too often, additional imaging is deemed wasteful, so having a model to separate the necessary from unnecessary is a good idea.

The model excerpted from the article…

• A supplemental image — many of which are medically necessary — would occur during the same clinical encounter but utilize a different modality, such as a non-contrast CT scan and a renal ultrasound to identify kidney stones.
• Duplicative images involve the same modality during the same or subsequent clinical session. These images are taken for a variety of reasons, including the unavailability of previous scans or a change in the patient’s condition.
• Follow-up imaging can involve the same or different modalities during later clinical meetings, such as repeated imaging in cancer patients to verify there’s been no relapse of disease.
• Unrelated imaging — scanning of the same body area with any modality — is often an unforeseen event. For example, in its paper, HPI discussed unrelated imaging in a woman who had CT screenings for breast cancer staging two weeks prior to a car accident that prompted identical scans.