title: Diagnostic performance of Tc-99m HMPAO SPECT for early and late onset Alzheimer's disease: a clinical evaluation of linearization correction.
abstract: OBJECTIVE
  This study examined the influence of linearization correction (LC) on brain perfusion single-photon emission computed tomography (SPECT) for the diagnosis of Alzheimer's disease (AD).
  
  
  METHODS
  The early onset group (<65 years old) consisted of 10 patients with AD, and the late onset group (>/=65 years old) of 13 patients with AD. Age-matched controls included seven younger and seven older normal volunteers. Tc-99m hexamethyl propyleneamine oxine (HMPAO) SPECT images were reconstructed with or without LC [LC (+) or LC (-)] and a statistical analysis was performed using a three-dimensional stereotactic surface projection (3D-SSP). In addition, a fully automatic diagnostic system was developed, which calculated the proportion of the number of abnormal pixels in the superior and inferior parietal lobule, as well as in the precuneus and posterior cingulate gyrus.
  
  
  RESULTS
  The areas under the receiver-operating characteristic curve (AUCs) of the early onset group for conventional axial SPECT images, SPECT + 3D-SSP images and the fully automatic diagnostic system were 0.71, 0.88, and 0.92 in LC (-) and 0.67, 0.85, and 0.91 in LC (+), respectively. The AUCs of the late onset group were 0.50, 0.61, and 0.79 in LC (-) and 0.49, 0.67, and 0.85 in LC (+), respectively.
  
  
  CONCLUSIONS
  LC on Tc-99m HMPAO SPECT did not significantly influence the diagnostic performance for differentiating between AD and normal controls in either early or late onset AD. Further examination with individuals suffering from very mild dementia is, therefore, expected to elucidate the effect of LC on minimally hypoperfused areas.
authors: Division of Radiological Science, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan.
authors: Tatsuya
authors: T
authors: Mitsumoto
authors: Nobuyoshi
authors: N
authors: Ohya
authors: Atsushi
authors: A
authors: Ichimiya
authors: Yuichi
authors: Y
authors: Sakaguchi
authors: Aya
authors: A
authors: Kiyota
authors: Koichiro
authors: K
authors: Abe
authors: Junji
authors: J
authors: Morishita
authors: Masayuki
authors: M
authors: Sasaki
mesh_terms: D017668:Age of Onset; D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019690:Technetium Tc 99m Exametazime