title: Use of a Single 11C-Meta-Hydroxyephedrine Scan for Assessing Flow-Innervation Mismatches in Patients with Ischemic Cardiomyopathy.
abstract: Mismatch between areas of reduced myocardial blood flow (MBF) and reduced myocardial innervation (defect areas) may be used to estimate the risk for ventricular arrhythmias. The presence of a mismatch zone can be derived using a combined protocol consisting of both an MBF scan and an (11)C-meta-hydroxyephedrine ((11)C-HED) scan. The rate of influx from blood to myocardium (K1) of (11)C-HED is proportional to MBF and can potentially be used as an index for defining MBF defects. The aim of this study was to assess whether K1 derived from an (11)C-HED scan can be used as an index of MBF, potentially allowing for an assessment of MBF-innervation mismatch areas from a single (11)C-HED scan.
  
  
  METHODS
  Seventeen patients with known ischemic cardiomyopathy underwent dynamic (15)O-water and (11)C-HED scans. Discrete arterial blood samples were taken during (11)C-HED scans for metabolite correction of the image-derived input function. (11)C-HED influx rate was obtained using a single-tissue-compartment model and compared with transmural MBF (MBFT), defined as MBF as measured with (15)O-water multiplied by perfusable tissue fraction. Defect sizes were obtained from parametric K1 and MBFT images, using 50% of a remote control segment as the cutoff value.
  
  
  RESULTS
  There was a significant correlation between MBFT and K1 (y = 0.40x + 0.05 mL·g(-1)·min(-1), r = 0.80, P < 0.001), although K1 was significantly lower than MBFT (slope of the regression line significantly different from 1, P < 0.001). Correlation between MBFT and K1 defect sizes was high (y = 0.89x + 1.38%, r = 0.95, P < 0.001), with no significant difference in mean defect size based on K1 or MBFT (20.9% ± 11.3% and 20.1% ± 10.7% for MBFT and K1, respectively, P = 0.41).
  
  
  CONCLUSIONS
  (11)C-HED influx rate K1 can be used as an alternative to a separate MBF scan for assessing mismatch areas between MBF and myocardial innervation.
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, Netherlands h.harms@vumc.nl.
authors.forename: Hendrik J
authors.initials: HJ
authors.lastname: Harms
authors.affiliation: Department of Nuclear Medicine and PET Research, Uppsala University, Uppsala, Sweden; and.
authors.forename: Mark
authors.initials: M
authors.lastname: Lubberink
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, Netherlands.
authors.forename: Stefan
authors.initials: S
authors.lastname: de Haan
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Knaapen
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, Netherlands.
authors.forename: Marc C
authors.initials: MC
authors.lastname: Huisman
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, Netherlands.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Schuit
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, Netherlands.
authors.forename: Albert D
authors.initials: AD
authors.lastname: Windhorst
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, Netherlands.
authors.forename: Cornelis P
authors.initials: CP
authors.lastname: Allaart
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, Netherlands.
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D004809:Ephedrine / Q000031:analogs & derivatives*; D005260:Female; D006321:Heart / Q000294:innervation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D010104:Oxygen Radioisotopes; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D013564:Sympathetic Nervous System / Q000000981:diagnostic imaging
chemical_list: D010104:Oxygen Radioisotopes; D019275:Radiopharmaceuticals; C065363:3-hydroxyephedrine; D004809:Ephedrine
keywords: 11C-HED; arrhythmias; innervation–blood flow mismatch; sympathetic denervation