Incidental Findings of Brain Magnetic Resonance Imaging Study in a Pediatric Cohort in Japan and Recommendation for a Model Management Protocol

Abstract

BackgroundThe increasing use of magnetic resonance imaging (MRI) in brain researches has led to growing concern over incidental findings (IFs). To establish a practical management protocol for IFs, it is useful to know the actual prevalence and problems of IF management. In the present study, we report the prevalence proportion and some handling problems of IFs in healthy Japanese children, and suggest a management protocol from ethical and practical standpoints.MethodsBetween 2006 and 2008, 120 healthy children aged 5–8 years participated in a structural MRI study conducted in a pediatric cohort in Japan. All MRI images were reviewed by a pediatric neurologist, and detected IFs were classified into 4 categories.ResultsIFs of all categories were detected in 40 of the 110 participants (36.4%) for whom T2-weighted or 3D-T1-weighted images were available. Findings of sinusitis and/or otitis media were most frequent (26.4%). Excluding these findings, the prevalence of IFs was still 10.9% (12 findings): 9 findings were categorized as “no referral” (8.2%), 2 as “routine referral” (1.8%), 1 as “urgent referral” (0.9%), and 0 as “immediate referral” (0.0%). In “routine referral” category, only one participant was referred for further examinations.ConclusionsAlthough the prevalence of IFs was high, the proportion of those requiring further examination was low. This result revealed a fairly high false-positive rate and suggested that evaluating equivocal findings was the most difficult part of IF management. A management protocol needs to include a process to properly assess the clinical importance of findings.

Discovery and informing research participants of incidental findings detected in brain magnetic resonance imaging studies: Review and multi‐institutional study

“…We reviewed one meta‐analysis and 14 reports (6 countries) (Boutet et al., 2016; Hartwigsen, Siebner, Deuschl, Jansen, & Ulmer, 2010; Hoggard, Darwent, Capener, Wilkinson, & Griffiths, 2009; Illes, Rosen, et al., 2004; Kaiser et al., 2015; Katzman et al., 1999; Kim et al., 2002; Kumra et al., 2006; Morris et al., 2009; Orme et al., 2010; Reneman et al., 2012; Royal & Peterson, 2008; Sandeman et al., 2013; Seki et al., 2010; Shoemaker et al., 2011). Details of the subject type and IF discovery rate (percentage of individuals in whom IFs were discovered to the total number of participants in whom images were taken) for each of the studies are summarized in Table 2.…”

“…Details of the subject type and IF discovery rate (percentage of individuals in whom IFs were discovered to the total number of participants in whom images were taken) for each of the studies are summarized in Table 2. IF discovery rates were also shown according to their classification by the level of urgency, which has been widely shown in previous studies: Urgency level 1 indicates that immediate referral is required (Immediate referral); urgency level 2 indicates that referral within a few weeks is required (Urgent referral); urgency level 3 indicates that routine referral is required (Routine referral); and urgency level 4 indicates that the finding is common among asymptomatic research participants, and no referral is required (No referral) (Illes, Rosen, et al., 2004; Kaiser et al., 2015; Katzman et al., 1999; Kim et al., 2002; Orme et al., 2010; Reneman et al., 2012; Royal & Peterson, 2008; Sandeman et al., 2013; Seki et al., 2010; Shoemaker et al., 2011) (Table 2). …”

“…The reason for this might be attributable to the institutional differences in either the definition of IFs, subject population, or reviewer or judgment process of images. For example, in the reports where the definition of IFs included the changes caused by aging or those considered to be normal variants, the discovery rate was relatively high from 18.0 to 47.0% (Boutet et al., 2016; Illes, Rosen, et al., 2004; Katzman et al., 1999; Kim et al., 2002; Orme et al., 2010; Royal & Peterson, 2008; Seki et al., 2010). In contrast, where IFs were defined as only significant abnormalities (Hoggard et al., 2009), and where normal variants (pineal cysts, hypoplasia of frontal sinus, and others) were excluded from the definition (Reneman et al., 2012), the rate was low, 8.8% and 9.4%, respectively.…”

“…(2009), the discovery rates of severe IFs with a significant impact on health and requiring treatment were 0.7% for neoplastic findings and 2.0% for nonneoplastic findings. For all other studies, the discovery rates of IFs of an urgency level of 2 or above were below 2.0% (Illes, Rosen, et al., 2004; Kaiser et al., 2015; Katzman et al., 1999; Kim et al., 2002; Orme et al., 2010; Royal & Peterson, 2008; Seki et al., 2010; Shoemaker et al., 2011). The border between the urgency levels 2 and 3, that is, whether or not the IF requires an urgent examination or treatment, was relatively clear.…”

“…From the above survey results, we used the following data: the number of research participants whose brain images were taken, the number of participants in whom IFs were discovered, basic attributes of IFs, types of equipment used for taking images, types of images, types of individual findings (suspected disease names), judgment of the urgency level of findings (one of the four levels of Immediate, Urgent, Routine, or No referral (Illes, Rosen, et al., 2004; Shoemaker et al., 2011; Katzman, Dagher, & Patronas, 1999; Seki, Uchiyama, Fukushi, Sakura, & Tatsuya, 2010; Kim, Illes, Kaplan, Reiss, & Atlas, 2002)), whether or not research participants were informed of the findings, and the informing method used when informed.…”