K. Fukuchi et al., Attenuation correction for cardiac dual-head gamma camera coincidence imaging using segmented myocardial perfusion SPECT, J NUCL MED, 41(5), 2000, pp. 919-925
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
The diagnostic accuracy of cardiac FDG imaging obtained with the dual-head
coincidence gamma camera (DHC) is impaired by artifacts induced by nonunifo
rm attenuation. This study proposed a new method (registration and segmenta
tion method for attenuation correction [AC-RS]) to correct these attenuatio
ns in the chest region without the need for additional hardware or expensiv
e transmission scanning equipment. Methods: Before DHC imaging, Tc-99m-tetr
ofosmin SPECT was performed using dual-energy acquisition from both the pho
topeak and Compton scatter windows. The scatter window images of the Tc-99m
-tetrofosmin were then registered 3-dimensionally with the cardiac DHC imag
es and segmented into anatomic regions to obtain body and lung contours by
applying the optimal threshold method on localized histograms. Theoretic at
tenuation coefficient Values were assigned to the corresponding anatomic re
gions, and the DHC emission images were reconstructed using these attenuati
on correction factors. The results were quantitatively evaluated by imaging
a cardiac phantom filled with a uniform solution and placed in a chest pha
ntom. Eight nondiabetic subjects were also examined using this technique, a
nd the results were compared with those of measured attenuation-corrected P
ET images. Results: Use of this technique in phantom and clinical studies d
ecreased the degree of artifacts seen in the inferior wall activity and cor
rected the emission images. When the results were compared with those of PE
T scans, the regional relative counts of the uncorrected DHC scan did not c
orrelate with the results of the PET scan. However, the regional relative c
ounts of the AG-RS-corrected DHC scan exhibited a linear correlation with t
he results of the PET scan (r = 0.73; P < 0.001), Conclusion: Reasonably ac
curate attenuation-corrected cardiac DHC images can be obtained using AC-RS
without the need for transmission scanning.