Actionable imaging findings in the daily PET/CT scenario

Abstract

Background and aim: The American College of Radiology (ACR) defines "actionable findings" the ones requiring a special communication between radiologists and referring clinicians, suggesting to organize their categorization in a three-degree scale on the basis of the risk for the patient to develop complications. These cases may fall in a grey-zone communication between different care figures with the risk of being underestimated or even not being considered at all. In this paper, our aim is to adapt the ACR categorization to the most frequent actionable findings encountered when reporting PET/CT images in a Nuclear Medicine Department, describing the most frequent and relevant imaging features and presenting the modalities of communication and the related clinical interventions that can be modulated by the prognostic severity of the clinical cases.

Materials and methods: We performed a descriptive, observational and critical analysis of the most relevant literature on the topic of "actionable findings", in particular, starting from the reports of the ACR Actionable Reporting Work Group, we categorised and described, in a narrative review, the most relevant "actionable findings" encountered in the Nuclear Medicine PET/CT daily practice.

Results: To the best of our knowledge, to date there are no clear indications on this selective PET/CT topic, considering that the current recommendations target mainly radiologists and assume a certain level of radiological expertise. We resumed and classified the main imaging conditions under the term of "actionable findings" according to the corresponding anatomical districts, and we described their most relevant imaging features (independently of PET avidity or not). Furthermore, a different communication timing and strategy was suggested on the basis of the findings' urgency.

Conclusion: A systematic categorization of the actionable imaging findings according to their prognostic severity may help the reporting physician to choose how and when to communicate with the referring clinician or to identify cases requiring a prompt clinical evaluation. Effective communication is a critical component of diagnostic imaging: timely receipt of the information is more important than the method of delivery.

Keywords: Actionable findings; Emergency; Nuclear Medicine; PET/CT.

Fig. 1

Category 1. Unknown lytic lesion of C2 body at risk of fracture (arrows) and lytic lesions of the skull detected on CT images of a whole-body [18F]-FDG PET/CT performed for staging multiple myeloma. a No FDG uptake was shown on PET images; b irregular margins and posterior wall cortical interruption was detected on the low-dose CT images. In this case the patient was sent to the emergency department where the orthopaedic counselling prescribed the use of a Philadelphia collar

Fig. 2

Category 3. a Abdominal aortic aneurism (arrows). a Maximum Intensity Projection (MIP) negative for focal tracer uptake. b aneurismatic tract on transaxial CT images; c aneurismatic tract on coronal CT images; d aneurismatic tract on PET/CT images showed physiologic blood pool uptake and aneurismatic lumen with mural calcifications; e aneurismatic tract measurement on transaxial CT images. In this case a urgent surgical counselling was requested to evaluate a possible surgical treatment

Fig. 3

Category 2. a FDG-PET/CT showed pulmonary consolidation on the right lung close to the broncus with mild FDG uptake. b High Resolution CT showed more clearly that the bronchus was going through the consolidation. In this case the patient required isolation due to the risk of contagious active infection