title: NIRS and IVUS for characterization of atherosclerosis in patients undergoing coronary angiography.
abstract: OBJECTIVE
  The aim of this study was to compare the findings of near-infrared spectroscopy (NIRS), intravascular ultrasound (IVUS) virtual histology (VH), and grayscale IVUS obtained in matched coronary vessel segments of patients undergoing coronary angiography.
  
  
  BACKGROUND
  Intravascular ultrasound VH has been developed to add tissue characterization to the grayscale IVUS assessment of coronary plaques. Near-infrared spectroscopy is a new imaging technique able to identify lipid core-containing coronary plaques (LCP).
  
  
  METHODS
  We performed NIRS and IVUS-VH pullbacks in a consecutive series of 31 patients with a common region of interest (ROI) between 2 side branches. For each ROI, we analyzed the chemogram blocks by NIRS, plaque area and plaque burden by grayscale IVUS, and tissue types by IVUS-VH. The chemogram block is a summary metric of a 2-mm vertical slice of the chemogram. The value ranges from 0 to 1 according to the presence of lipids and represents the probability of LCP with a color scale from red (low probability) through orange and tan to yellow (high probability).
  
  
  RESULTS
  Plaque area (mm(2)) increases as percentage VH derived-necrotic core (NC) content (4.6 ± 2.7 vs. 7.4 ± 3.5 vs. 8.6 ± 3.4 vs. 7.9 ± 3.3, grouped in percentage NC quartiles, p<0.001) and chemogram block probability color bin thresholds increase (4.9 ± 3.8 red, 7.3 ± 3.6 orange, 8.1 ± 3.4 tan, and 8.7 ± 3.4 yellow, p<0.001). The correlation between the block chemogram detection of lipid core and percentage NC content by VH was weak (r=0.149). Correction for the presence of calcium does not improve this correlation.
  
  
  CONCLUSIONS
  Larger plaque area by grayscale IVUS was more often associated with either elevated percentage VH-NC or LCP by NIRS; however, the correlation between the detection of LCP by NIRS and necrotic core by VH is weak.
authors.affiliation: Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Brugaletta
authors.forename: Hector M
authors.initials: HM
authors.lastname: Garcia-Garcia
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
authors.forename: Sanneke
authors.initials: S
authors.lastname: de Boer
authors.forename: Jurgen
authors.initials: J
authors.lastname: Ligthart
authors.forename: Josep
authors.initials: J
authors.lastname: Gomez-Lara
authors.forename: Karen
authors.initials: K
authors.lastname: Witberg
authors.forename: Roberto
authors.initials: R
authors.lastname: Diletti
authors.forename: Joanna
authors.initials: J
authors.lastname: Wykrzykowska
authors.forename: Robert-Jan
authors.initials: RJ
authors.lastname: van Geuns
authors.forename: Carl
authors.initials: C
authors.lastname: Schultz
authors.forename: Evelyn
authors.initials: E
authors.lastname: Regar
authors.forename: Henricus J
authors.initials: HJ
authors.lastname: Duckers
authors.forename: Nicolas
authors.initials: N
authors.lastname: van Mieghem
authors.forename: Peter
authors.initials: P
authors.lastname: de Jaegere
authors.forename: Sean P
authors.initials: SP
authors.lastname: Madden
authors.forename: James E
authors.initials: JE
authors.lastname: Muller
authors.forename: Antonius F W
authors.initials: AF
authors.lastname: van der Steen
authors.forename: Wim J
authors.initials: WJ
authors.lastname: van der Giessen
authors.forename: Eric
authors.initials: E
authors.lastname: Boersma
mesh_terms: D000368:Aged; D002114:Calcinosis / Q000175:diagnosis; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008055:Lipids / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D009426:Netherlands; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012720:Severity of Illness Index; D019265:Spectroscopy, Near-Infrared; D018084:Ultrasonography, Interventional
chemical_list: D008055:Lipids