"Working diagnosis and differential "
"Scoring systems and measurements "
"5. DWI "
"posterior atrophy score of parietal atrophy (PA or PCA or Koedam score): useful in atypical (posterior cortical atrophy) or early-onset Alzheimer disease."
"hippocampal volume: sagittal is a surprisingly good plane for the hippocampi provided you have thin enough imaging. You should see them to be plump grey matter signal intensity sausage-shaped structures with the choroidal fissure above them, which may contain small cysts or focal expansions containing choroid. The hippocampi slightly taper as you progress from anterior to posterior. Reversal of this tapering may be seen in FTLD. In contrast, general atrophy is seen Alzheimer disease."
"e.g. "In this age group and in the setting of visual symptoms and apraxias, bilateral relatively subtle parietal volume loss supports the clinical diagnosis of posterior cortical atrophy"."
"In addition to systematically going through each scan, it is worth specifically looking for some signs, which will ensure you do not miss a diagnosis which will in retrospect be obvious. Having said this, many of these signs are only useful (if at all) late in the course of the disease at which time the diagnosis is often already obvious clinically.Nonetheless, some of the better-known signs include:"
"don't overcall the hummingbird sign of PSP"
"Don't forget to look at everything else too. Sagittal T1 is often your largest field of view sequence and will be the only one to image the oral cavity, TMJ, and upper cervical spine and cord."
"don't forget to ask yourself whether the temporal horn is big or the hippocampus is small"
"don't overcall Mickey Mouse sign or morning glory sign of PSP"
"Don't forget that T2 sequences usually give you the best look at the intracranial arteries, so make sure you look for aneurysms or vascular malformations."
"This is particularly important if findings are subtle or contradictory or if adequate clinical information is absent. In the latter scenario, an attempt to obtain it should be made and the author of the request card gently chastised :)"
"Fazekas scale for white matter lesions: the deep white matter component is used in assessing the amount of chronic small vessel ischaemic change"
"Motor band sign of ALS"
"Sylvian fissure and cistern size"
"posterior atrophy score of parietal atrophy (PA or PCA or Koedam score): useful in atypical (posterior cortical atrophy) or early-onset Alzheimer disease."
"posterior atrophy score of parietal atrophy (PA or PCA or Koedam score): useful in atypical (posterior cortical atrophy) or early-onset Alzheimer disease."
"entorhinal cortical atrophy score (ERICA score)"
"global cortical atrophy scale (GCA scale)"
"Motor band sign of ALS"
"hippocampal volume: sagittal is a surprisingly good plane for the hippocampi provided you have thin enough imaging. You should see them to be plump grey matter signal intensity sausage-shaped structures with the choroidal fissure above them, which may contain small cysts or focal expansions containing choroid. The hippocampi slightly taper as you progress from anterior to posterior. Reversal of this tapering may be seen in FTLD. In contrast, general atrophy is seen Alzheimer disease."
"Don't forget to look at everything else too. Sagittal T1 is often your largest field of view sequence and will be the only one to image the oral cavity, TMJ, and upper cervical spine and cord."
"left > right atrophy favours FTLD"
"anterior atrophy > posterior atrophy favours FTLD"
"involvement of the temporal lobe generally favours FTLD"
"in FTLD typically left > right"
"look for atrophy and high T2 signal of middle cerebellar peduncle sign (MSA-C, FXTAS, etc...)"
"size and flow void in aqueduct (usually prominent in NPH)"
"3. Axial FLAIR & T2"
"look for atrophy and high T2 signal of middle cerebellar peduncle sign (MSA-C, FXTAS, etc...)"
"look for atrophy and high T2 signal of middle cerebellar peduncle sign (MSA-C, FXTAS, etc...)"
Expected headings
"Main conditions"
"Importance of clinical history"
"Clinical information"
"Working diagnosis and differential "
"Scoring systems and measurements "
"Signs"
"Systematic approach"
"1. T1 sagittal"
"2. Coronal sequences"
"3. Axial FLAIR & T2"
"4. T2* sequences"
"5. DWI "
"Putting it all together"
"As such the true role of imaging is often to push clinicians towards or away from a particular diagnosis rather than making a firm unwavering diagnosis; in other words, it is an exercise in applied Bayesian thinking."
"subcortical/deep white matter in chronic small vessel ischaemia (common); consider multi-infarct dementia"
"memory problems (e.g. short term / long term / ante-grade / retrograde)"
"language problems (e.g. receptive, expressive)"
"personality change (e.g. disinhibition, aggression)"
"the pons should be plump and rounded and about 4 times as large as the midbrain. Be prepared to look for pontine atrophy if it looks small or flattened (e.g. multiple system atrophy)"
"atrophy of the vermis (e.g. in alcohol use and antiepilepsy medication)"
"There are many variations on a 'neurodegenerative protocol' and much will depend upon local preferences and equipment. What is essential is that good quality three plane imaging (sagittal, coronal, and axial) with T1, T2, FLAIR, DWI, and T2* (e.g SWI) sequences."
"There are many variations on a 'neurodegenerative protocol' and much will depend upon local preferences and equipment. What is essential is that good quality three plane imaging (sagittal, coronal, and axial) with T1, T2, FLAIR, DWI, and T2* (e.g SWI) sequences."
"midbrain shape, size and midbrain to pons area ratio"
"medial surfaces of the frontal, parietal and occipital lobes"
"mammillary body size, signal and symmetry"