title: Quantification of coronary flow using dynamic angiography with 320-detector row CT and motion coherence image processing: Detection of ischemia for intermediate coronary stenosis.
abstract: OBJECTIVE
  Anatomical coronary stenosis is not always indicative of functional stenosis, particularly for intermediate coronary lesions. The purpose of this study is to propose a new method for quantifying coronary flow using dynamic CT angiography for the whole heart (heart-DCT) and investigate its ability for detecting ischemia from intermediate coronary stenosis.
  
  
  METHODS
  Participants comprised 36 patients with coronary artery disease who underwent heart-DCT using 320-detector CT with tube voltage of 80kV and myocardial perfusion scintigraphy (MPS). Heart-DCT was continuously performed at mid-diastole throughout 15-25 cardiac cycles with prospective ECG-gating after bolus injection of contrast media (12-24ml). Dynamic datasets were computed into 90-100 data sets by motion coherence image processing (MCIP). Next, time-density curves (TDCs) for coronary arteries with a diameter >3mm were automatically calculated for all phases using MCIP. On the basis of the maximum slope method, coronary flow index (CFI) was defined as the ratio of the maximum upslope of coronary artery attenuation to the upslope of ascending aorta attenuation on the TDC, and was used to quantify coronary flow. CFIs for the proximal and distal sites of coronary arteries with mild-to-moderate stenosis were calculated. Coronary territories were categorized as non-ischemic or ischemic by MPS. Receiver-operating-characteristic (ROC) analysis was performed to determine the optimal cutoff for CFI to detect ischemia.
  
  
  RESULTS
  Distal CFI was significantly lower for ischemia (0.26±0.08) than for non-ischemia (0.50±0.17, p<0.0001). No significant difference in proximal CFI was seen between ischemia (0.55±0.23) and non-ischemia (0.62±0.24). ROC analysis revealed 0.39 as the optimal cutoff for distal CFI to detect ischemia, with C-statistics of 0.91, 100% sensitivity, and 75% specificity.
  
  
  CONCLUSIONS
  This novel imaging technique allows coronary flow quantification using heart-DCT. Distal CFI can detect myocardial ischemia derived from intermediate coronary stenosis.
authors.affiliation: Departments of Molecular Imaging & Diagnosis, Graduate School of Medical Sciences, Kyushu University, Japan. Electronic address: minagao@radiol.med.kyushu-u.ac.jp.
authors.forename: Michinobu
authors.initials: M
authors.lastname: Nagao
authors.affiliation: Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Yamasaki
authors.affiliation: Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kamitani
authors.affiliation: Departments of Molecular Imaging & Diagnosis, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kawanami
authors.affiliation: Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Sagiyama
authors.affiliation: Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Torahiko
authors.initials: T
authors.lastname: Yamanouchi
authors.affiliation: Departments of Medical Technology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Yamato
authors.initials: Y
authors.lastname: Shimomiya
authors.affiliation: Departments of Cardiovascular Medicine, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Matoba
authors.affiliation: Departments of Cardiovascular Medicine, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Mukai
authors.affiliation: Departments of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Odashiro
authors.affiliation: Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Baba
authors.affiliation: Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Maruoka
authors.affiliation: Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kitamura
authors.affiliation: Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Nishie
authors.affiliation: Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000368:Aged; D000072226:Computed Tomography Angiography / Q000379:methods*; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003326:Coronary Circulation / Q000502:physiology; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D064847:Multimodal Imaging / Q000379:methods; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013312:Stress, Physiological / Q000502:physiology; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D041623:Tomography, Optical Coherence / Q000379:methods; D014664:Vasodilation / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D003287:Contrast Media; D014665:Vasodilator Agents
keywords: Coronary artery disease; Coronary computed tomography angiography; Motion coherence analysis; Myocardial perfusion scintigraphy