[Diagnostic imaging in dementia: use of imaging modalities in Dutch memory clinics]

To evaluate the use of MRI and CT in the diagnostic work-up of dementia in Dutch memory clinics, and to analyse the rationale for choosing each modality.

A digital survey was sent by e-mail to all medical specialists (n=235) working at a memory clinic in the Netherlands.

The survey was completed by 64% (151). 85% of the respondents were geriatricians, 13% neurologists and 2% other, working at a total of 69 clinics. 40% variably orders CT or MRI, 37% orders MRI, 19% CT, and 4% CT plus MRI. Primary factors influencing this choice are: MRI contraindications, physical limitations, age, vascular or oncological medical history, and waiting time. With CT, 87% indicates information is lacking: vascular disease/white matter lesions, (hippocampal) atrophy, and specific pathologies (metastases, amyloid angiopathy). Furthermore, respondents prefer MRI because they can assess the images more easily themselves. Only 50% of respondents indicate that CT protocol dictates coronal reconstructions. Additionally, these reconstructions are not provided consistently. Rating-scales are used to describe images in 5%. In 75% assessment is not uniform.

MRI is preferred over CT in diagnostic imaging of dementia, in accordance with existing guidelines. However, these guidelines are mostly out-dated and modern multislice CT potential is relatively unknown among geriatricians. In memory clinics, multislice CT could offer a well suitable imaging alternative, but only if multiplanar reconstructions are performed consistently. Furthermore, radiology reports need to be improved by using more standardized assessment.