17 Nov 20. Featured Paper
Pharmacokinetic modelling for the simultaneous assessment of perfusion & 18F-flutemetamol uptake in cerebral amyloid angiopathy using a reduced PET-MR acquisition time: Proof of concept
Purpose: Cerebral amyloid angiopathy (CAA) is a cerebral small vessel disease associated with perivascular β-amyloid deposition.
CAA is also associated with strokes due to lobar intracerebral haemorrhage (ICH).
18F-flutemetamol amyloid ligand PET may improve the early detection of CAA.
We performed pharmacokinetic modelling using both full (0–30, 90–120 min) & reduced (30 min) 18F-flutemetamol PET-MR acquisitions, to investigate regional cerebral perfusion & amyloid deposition in ICH patients.
Methods: Dynamic18F-flutemetamol PET-MR was performed in a pilot cohort of sixteen ICH participants; eight lobar ICH cases with probable CAA & eight deep ICH patients.
A model-based input function (mIF) method was developed for compartmental modelling.
mIF 1-tissue (1-TC) & 2-tissue (2-TC) compartmental modelling, reference tissue models & standardized uptake value ratios were assessed in the setting of probable CAA detection.
Results: The mIF 1-TC model detected perfusion deficits & 18F-flutemetamol uptake in cases with probable CAA versus deep ICH patients, in both full & reduced PET acquisition time (all P < 0.05).
In the reduced PET acquisition, mIF 1-TC modelling reached the highest sensitivity & specificity in detecting perfusion deficits (0.87, 0.77) & 18F-flutemetamol uptake (0.83, 0.71) in cases with probable CAA.
Overall, 52 & 48 out of the 64 brain areas with 18F-flutemetamol-determined amyloid deposition showed reduced perfusion for 1-TC & 2-TC models, respectively.
Conclusion: Pharmacokinetic (1-TC) modelling using a 30 min PET-MR time frame detected impaired haemodynamics & increased amyloid load in probable CAA.
Perfusion deficits & amyloid burden co-existed within cases with CAA, demonstrating a distinct imaging pattern which may have merit in elucidating the pathophysiological process of CAA.
- 18F-flutemetamol uptake
- Cerebral amyloid angiopathy
- Magnetic resonance imaging
- Pharmacokinetic modelling
- Positron emission tomography
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Featured paper: Pharmacokinetic modelling for the simultaneous assessment of perfusion & 18F-flutemetamol uptake in cerebral amyloid angiopathy using a reduced PET-MR acquisition time: Proof of concept @BleedingStroke #MR #PET