Comparative value of brain perfusion SPECT and [(123)I]MIBG myocardial scintigraphy in distinguishing between dementia with Lewy bodies and Alzheimer's disease.
OBJECTIVE
Both decreased occipital perfusion on brain single-photon emission computed tomography (SPECT) and reduction in cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake are characteristic features of dementia with Lewy bodies (DLB), and potentially support the clinical diagnosis of DLB. The aim of this study was to compare the diagnostic value of these two methods for differentiation of DLB from Alzheimer's disease (AD).


METHODS
The study population comprised 19 patients with probable DLB and 39 patients with probable AD who underwent both SPECT with N-isopropyl-p-[(123)I]iodoamphetamine and MIBG myocardial scintigraphy. Objective and quantitative measurement of perfusion in the medial occipital lobe, including the cuneus and lingual gyrus, was performed by the use of three-dimensional stereotactic surface projections.


RESULTS
Medial occipital perfusion was significantly decreased in the DLB group compared with the AD group. The mean heart/mediastinum ratios of MIBG uptake were significantly lower in the DLB group than in the AD group. Although SPECT failed to demonstrate significant hypoperfusion in the medial occipital lobe in five patients with DLB, marked reduction of MIBG uptake was found in all patients with DLB. Receiver operating characteristic analysis revealed that MIBG myocardial scintigraphy enabled more accurate discrimination between DLB and AD than was possible with perfusion SPECT.


CONCLUSIONS
MIBG myocardial scintigraphy may improve the sensitivity in the detection of DLB. In particular, this method may provide a powerful differential diagnostic tool when it is difficult to distinguish cases of DLB from AD using brain perfusion SPECT.
Hanyu
Haruo
H
Department of Geriatric Medicine, Tokyo Medical University, 6-7-1 Nishishinjuku Shinjuku-ku, Tokyo 160-0023, Japan. h-hanyu@tokyo-med.ac.jp
Shimizu
Soichiro
S
Hirao
Kentaro
K
Kanetaka
Hidekazu
H
Iwamoto
Toshihiko
T
Chikamori
Taishiro
T
Usui
Yasuhiro
Y
Yamashina
Akira
A
Koizumi
Kiyoshi
K
Abe
Kimihiko
K
D019797:3-Iodobenzylguanidine; D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D001921:Brain / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D006801:Humans; D020367:Iofetamine; D020961:Lewy Body Disease / Q000000981:diagnostic imaging*; D010477:Perfusion / Q000379:methods; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine; D020367:Iofetamine