title: Improvement of quantification of myocardial first-pass perfusion mapping: a temporal and spatial wavelet denoising method.
abstract: Mapping of myocardial blood flow (MBF) with first-pass perfusion imaging is becoming an important tool in the study of coronary artery disease. In this study a wavelet-based denoising method was developed to improve the accuracy of pixel-by-pixel MBF maps. We performed an in vivo study in five stenotic dogs with 70% stenosis in the left coronary arteries. First-pass perfusion imaging sessions were performed by administering the intravascular contrast agent Gadomer at rest and during dipyridamole-induced vasodilation. Color microspheres (MS) were injected into the dogs to measure MBF at the same time. After denoising was performed, the signal-to-noise ratio (SNR) of the first-pass perfusion image improved by approximately 180%, whereas spatial variation of MBF maps decreased 38%. It was also found that the correlation of MBFs measured by MRI with the MS method indicates a significant improvement with the denoising method (R2 increased from 0.24 to 0.78, P < .001). This suggests that the wavelet denoising method may be an effective way to increase the accuracy of pixel-by-pixel MBF quantification and reduce spatial variation, and may be applicable to other forms of noise-sensitive image analysis.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri 63110, USA.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Goldstein
authors.forename: Haosen
authors.initials: H
authors.lastname: Zhang
authors.forename: Bernd
authors.initials: B
authors.lastname: Misselwitz
authors.forename: Robert G
authors.initials: RG
authors.lastname: Gropler
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
mesh_terms: D000818:Animals; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology; D023921:Coronary Stenosis / Q000473:pathology*; D050091:Dendrimers; D004176:Dipyridamole / Q000494:pharmacology; D004285:Dogs; D004562:Electrocardiography; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008863:Microspheres
chemical_list: D003287:Contrast Media; D050091:Dendrimers; C513348:gadomer 24; D004176:Dipyridamole