Voxel-based correlation between coregistered single-photon emission computed tomography and dynamic susceptibility contrast magnetic resonance imaging in subjects with suspected Alzheimer disease.
BACKGROUND
Current diagnosis of Alzheimer disease is made by clinical, neuropsychologic, and neuroimaging assessments. Neuroimaging techniques such as magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) could be valuable in the differential diagnosis of Alzheimer disease, as well as in assessing prognosis.


OBJECTIVE
To compare SPECT and MRI in a cohort of patients examined for suspected dementia, including patients with no objective cognitive impairment (control group), mild cognitive impairment (MCI), and Alzheimer disease (AD).


METHODS
24 patients, eight with AD, 10 with MCI, and six controls, were investigated with SPECT using (99m)Tc-hexamethylpropyleneamine oxime (HMPAO, Ceretec; GE Healthcare Ltd., Little Chalsont UK) and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with a contrast-enhancing gadobutrol formula (Gadovist; Bayer Schering Pharma, Berlin, Germany). Voxel-based correlation between coregistered SPECT and DSC-MR images was calculated. Region-of-interest (ROI) analyses were then performed in 24 different brain areas using brain registration and analysis of SPECT studies (BRASS; Nuclear Diagnostics AB, Stockholm, Sweden) on both SPECT and DSC-MRI.


RESULTS
Voxel-based correlation between coregistered SPECT and DSC-MR showed a high correlation, with a mean correlation coefficient of 0.94. ROI analyses of 24 regions showed significant differences between the control group and AD patients in 10 regions using SPECT and five regions in DSC-MR.


CONCLUSIONS
SPECT remains superior to DSC-MRI in differentiating normal from pathological perfusion, and DSC-MRI could not replace SPECT in the diagnosis of patients with Alzheimer disease.
Division of Radiology, Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden. lena.cavallin@karolinska.se
L
L
Cavallin
R
R
Axelsson
L O
LO
Wahlund
A R
AR
Oksengard
L
L
Svensson
P
P
Juhlin
M Kristoffersen
MK
Wiberg
A
A
Frank
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis*; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods; D015331:Cohort Studies; D003287:Contrast Media; D003937:Diagnosis, Differential; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D011237:Predictive Value of Tests; D011859:Radiography; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol; D019690:Technetium Tc 99m Exametazime