Since the beginning of the 1990s, functional Magnetic Resonance Imaging (fMRI) has become an important technique in cognitive neuroscience. An MRI scanner can acquire low-definition pictures of the human brain in only 2s, and this is repeatedly done for the whole duration of a certain cognitive task, e.g. recognizing the emotions expressed by human faces that are shown on a screen.

Change over time in these low-definition images can be used as a measure of cerebral blood flow, which is linked to neural metabolism. However, these pictures need to be compared with a high-definition picture of the brain in order to understand exactly where the changes in blood flow occur. Through this high-definition picture, it is also possible to spot abnormalities in the brain. However, when this happens, two problems arise. First, the person who is performing the scan and examining the resulting images is usually a grad student or a PhD in psychology / neuroscience and not a Medical Doctor (MD). Second, in many cases the scan is not performed in a clinical setting (e.g., a hospital) but in a psychology department and for sure the participant is not scanned as a part of a medical procedure, i.e. the purpose of the scan is not clinical. Nonetheless, medically relevant information can be detected. Given the very high number of research MRI scans performed nowadays, even a low rate of clinically relevant incidental findings may give rise to a total of many cases. The most famous case is that of Sarah Hilgenberg (1), a medical student at Stanford in whose brain an Arterio-Venous Malformation (AVM) was found during a cognitive neuroimaging experiment. Her AVM in the frontal lobe could have bled any time, leading to severe brain damage and eventually death. The surgery Sarah later underwent was possibly life saving. Hence, a lot of harm can potentially be prevented through the communication of incidental findings. We know from empirical studies (2) that participants expect scans to be reviewed for incidental findings and that an overwhelming majority of them would like to be told if any clinically relevant abnormality existed.

Given this preference, researchers ought to create transparent protocols to manage incidental findings and their communication. Incidental findings should be mentioned in the informed consent form and the right of the participant to decide not to know must be protected. If a participant decides not to be informed, she should thereby discharge the researchers from all legal liabilities relative to future pathologies that could have been detected. As it is well known that participants usually do not read informed consent forms in their entirety, it would be advisable that a trained person should orally explain the procedure for incidental findings to participants. If the participant is interested in knowing, the researchers can then adopt different strategies. The option that protects participants most is having an MD look for incidental findings in all structural images, as a routine procedure, but this can be expensive and not all research teams in cognitive neuroscience include an MD.

Another option is to pass those structural images that are potentially suspicious to an MD, following macroscopic screening by a person who lacks medical training. It will then be up to the MD to decide whether the finding is clinically relevant or not. Communication of the incidental finding ought to be carried out by the MD directly to the participant. No disclosure to other parties ought to be performed without explicit consent of the participant, in order to avoid potential problems with insurers.

Responsibility for clinical follow-up and financial costs thereof seem to lie with the participants and not with the researchers, even though an ethical problematic situation arises when the participant to whom a clinically relevant incidental finding has been notified has no means (e.g., because she is under-insured) to carry out the relevant therapy.

A very difficult moral quandary arises when a potentially lethal finding (e.g. a brain malignancy) is spotted in the brain of a participant who has opted for not knowing. This creates the classical autonomy vs. beneficence clash: should we respect the informed will of the patient and thereby harm her or override her will and benefit her? I cannot address this very hard problem here, but it is important that researchers in cognitive neuroscience take the existence of incidental findings into account when planning experimental protocols. Due to the high number of people nowadays involved as participants in cognitive neuroimaging, incidental findings will become a concrete experience for many labs.

References

1. Hilgenberg, S. (2006). Transformation: From Medical Student to Patient. Annals of Internal Medicine 144:779-780.
2. Kirschen, M. P., Jaworska, A., & Illes, J. (2006). Subjects‘ Expectations in Neuroimaging Research. Journal of Magnetic Resonance Imaging 23:205-209