Imaging of amyloid burden and distribution in cerebral amyloid angiopathy.
OBJECTIVE
Cerebrovascular deposition of beta-amyloid (cerebral amyloid angiopathy [CAA]) is a major cause of hemorrhagic stroke and a likely contributor to vascular cognitive impairment. We evaluated positron emission tomographic imaging with the beta-amyloid-binding compound Pittsburgh Compound B (PiB) as a potential noninvasive method for detection of CAA. We hypothesized that amyloid deposition would be observed with PiB in CAA, and based on the occipital predilection of CAA pathology and associated hemorrhages, that specific PiB retention would be disproportionately greater in occipital lobes.


METHODS
We compared specific cortical PiB retention in 6 nondemented subjects diagnosed with probable CAA with 15 healthy control subjects and 9 patients with probable Alzheimer's disease (AD).


RESULTS
All CAA and AD subjects were PiB-positive, both by distribution volume ratio measurements and by visual inspection of positron emission tomographic images. Global cortical PiB retention was significantly increased in CAA (distribution volume ratio 1.18 +/- 0.06) relative to healthy control subjects (1.04 +/- 0.10; p = 0.0009), but was lower in CAA than in AD subjects (1.41 +/- 0.17; p = 0.002). The occipital-to-global PiB ratio, however, was significantly greater in CAA than in AD subjects (0.99 +/- 0.07 vs 0.86 +/- 0.05; p = 0.003).


CONCLUSIONS
We conclude that PiB-positron emission tomography can detect cerebrovascular beta-amyloid and may serve as a method for identifying the extent of CAA in living subjects.
Johnson
Keith A
KA
Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, USA.
Gregas
Matt
M
Becker
John A
JA
Kinnecom
Catherine
C
Salat
David H
DH
Moran
Erin K
EK
Smith
Erin E
EE
Rosand
Jonathan
J
Rentz
Dorene M
DM
Klunk
William E
WE
Mathis
Chester A
CA
Price
Julie C
JC
Dekosky
Steven T
ST
Fischman
Alan J
AJ
Greenberg
Steven M
SM
D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000378:metabolism / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds; D001706:Biopsy; D016657:Cerebral Amyloid Angiopathy / Q000150:complications / Q000000981:diagnostic imaging* / Q000378:metabolism*; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging; D015331:Cohort Studies; D004493:Education; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009778:Occipital Lobe / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D013844:Thiazoles
C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D019275:Radiopharmaceuticals; D013844:Thiazoles