The clinical decision support required information about the level of clinical suspicion for pulmonary embolism (low, intermediate, or high) and the serum D-dimer level (not done, unknown, normal, or elevated). (A) If no information was provided for these variables, the application presented the user with message A and prompted them to provide additional clinical information (add indication). (B) Imaging requests for patients with a normal D-dimer level and intermediate or low suspicion for pulmonary embolism received message B. (C) Imaging requests for patients with an intermediate or low level of clinical suspicion without a D-dimer received message C. (D) No decision support was presented if the request was deemed appropriate. CT = computed tomography; CTPA = computed tomography pulmonary angiography; PE = pulmonary embolism.