Incidental findings on brain imaging and blood tests: results from the first phase of Insight 46, a prospective observational substudy of the 1946 British birth cohort
Objective To summarise the incidental findings detected on
brain imaging and blood tests during the first wave of data
collection for the Insight 46 study.
Design Prospective observational sub-study of a birth
cohort.
Setting Single-day assessment at a research centre in
London, UK.
Participants 502 individuals were recruited from the MRC
National Survey of Health and Development (NSHD), the 1946
British birth cohort, based on pre-specified eligibility criteria;
mean age was 70.7 (SD: 0.7) and 49% were female.
Outcome measures Data regarding the number and types
of incidental findings were summarised as counts and
percentages, and 95% confidence intervals were calculated.
Results 93.8% of participants completed a brain scan
(n=471); 4.5% of scanned participants had a pre-defined
reportable abnormality on brain MRI (n=21); suspected
vascular malformations and suspected intracranial mass
lesions were present in 1.9% (n=9) and 1.5% (n=7)
respectively; suspected cerebral aneurysms were the
single most common vascular abnormality, affecting 1.1%
of participants (n=5), and suspected meningiomas were
the most common intracranial lesion, affecting 0.6% of
participants (n=3); 34.6% of participants had at least one
abnormality on clinical blood tests (n=169), but few reached
the prespecified threshold for urgent action (n=11).
Conclusions In older adults, aged 69-71 years, potentially
serious brain MRI findings were detected in around 5%
of participants, and clinical blood test abnormalities were
present in around one third of participants. Knowledge of
the expected prevalence of incidental findings in the general
population at this age is useful in both research and clinical
settings