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.
Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, USA.
Keith A
KA
Johnson
Matt
M
Gregas
John A
JA
Becker
Catherine
C
Kinnecom
David H
DH
Salat
Erin K
EK
Moran
Erin E
EE
Smith
Jonathan
J
Rosand
Dorene M
DM
Rentz
William E
WE
Klunk
Chester A
CA
Mathis
Julie C
JC
Price
Steven T
ST
Dekosky
Alan J
AJ
Fischman
Steven M
SM
Greenberg
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