TABLE 4.

Use of neuroimaging and fluid biomarkers

Structural Imaging

1. Even in older subjects, anatomical neuroimaging is recommended in most situations, using the following list of indications: onset of cognitive signs/symptoms within the past 2 years, regardless of the rate of progression; unexpected and unexplained decline in cognition and/or functional status in a patient already known to have dementia; recent and significant head trauma; unexplained neurological manifestations (new onset severe headache, seizures, Babinski sign, etc.), at onset or during evolution (this also includes gait disturbances); history of cancer, in particular if “at risk” for brain metastases; subject at risk for intracranial bleeding; symptoms compatible with normal pressure hydrocephalus; significant vascular risk factors. 1C (76%; 93%)

2. Magnetic resonance imaging (MRI) is recommended over computed tomography (CT), especially given its higher sensitivity to vascular lesions as well as for some subtypes of dementia and rarer conditions (2C). (87%) If available, and in the absence of contraindications, 3T MRI should be favoured over 1.5 T. (2C) (91%) If MRI is performed, we recommend the use of the following sequences: 3D T1 volumetric sequence (including coronal reformations for the purpose of hippocampal volume assessment), fluid‐attenuated inversion recovery (FLAIR), T2 (or if available susceptibility‐weighted imaging [SWI]) and diffusion‐weighted imaging (DWI). 1C (98%) We recommend against the routine clinical use of advanced MR sequences such as rs‐FMRI, MR spectroscopy, diffusion tensor imaging (DTI), and arterial spin labelling (ASL). However, these sequences are promising research tools that can be incorporated in a research setting or if access to advanced expertise is present. 2C (98%)

3. If CT is performed, we recommend a non‐contrast CT and coronal reformations are encouraged to better assess hippocampal atrophy. 1C (100%)

4. We recommend the use of semi‐quantitative scales for routine interpretation of both MRI and CT scans including: the medial temporal lobe atrophy (MTA) scale for medial temporal involvement, Fazekas scale 88 for white matter changes, and global cortical atrophy (GCA) to qualify global atrophy. 1C (96%)

5. We recommend against the routine clinical use of quantification software pending larger studies demonstrating the added diagnostic value of these tools. Of note, this is a rapidly evolving field and such recommendation could change in the future. 2C (93%)

Functional and Ligand‐Based Imaging

3a. For a patient with a diagnosis of a cognitive impairment who has undergone the recommended baseline clinical and structural brain imaging evaluation and who has been evaluated by a cognitive disorders specialist but whose underlying pathological process is still unclear, preventing adequate clinical management, an [18F]‐FDG PET scan is an effective and accurate tool for differential diagnosis purposes. 1A (88%)

3b. If such a patient cannot be practically referred for a FDG‐PET scan, we recommend that a SPECT rCBF study be performed for differential diagnosis purposes. 1B(86%)

4a. As recommended by The Amyloid Imaging Task Force of the Alzheimer's Association 77 and Society for Nuclear Medicine and Molecular Imaging 89 as well as by The Canadian Consensus Conference on the Use of Amyloid Imaging, 90 ordering PET amyloid imaging tests should be limited to dementia experts. 1A (98%)

4b. Because of cost issues, it is preferable to obtain an [18F]‐FDG PET (fluorodeoxyglucose positron emission tomography) scan before proceeding to amyloid imaging. 1A (90%)

4c. Use should follow The Amyloid Imaging Task Force of the Alzheimer's Association and Society for Nuclear Medicine and Molecular Imaging as well as The Canadian Consensus Conference on the Use of Amyloid Imaging appropriate use criteria. This will result in improved diagnostic classification and management. 1B (93%)

5a. [123I]‐Ioflupane and single‐photon emission computed tomography (SPECT; DaTscan) can be useful to establish a diagnosis of cognitive impairment linked to Lewy Body Disease in cases where such a diagnosis is suspected but remains unconfirmed after evaluation by a specialist with experience in the evaluation of neurodegenerative disease, thereby preventing adequate clinical management. 2B (93%)

5b. Because of cost issues, it is preferable to obtain an [18F]‐FDG PET scan before proceeding to [123I]‐Ioflupane SPECT (DaTscan), as this has a high probability of establishing the diagnosis. 1A (93%)

Fluid Biomarkers

6. Cerebrospinal fluid (CSF) analysis is not recommended routinely, but it can be considered in dementia patients with diagnostic uncertainty and onset at an early age (<65) to rule out Alzheimer's disease (AD) pathophysiology. 1C (78%; 100%)

7. CSF analysis can also be considered in dementia patients with diagnostic uncertainty and predominance of language, visuospatial, dysexecutive, or behavioral features to rule out AD pathophysiology. 1C (78%; 100%)