title: Myocardial perfusion reserve compared with peripheral perfusion reserve: a [13N]ammonia PET study.
abstract: BACKGROUND
  [13N]ammonia PET allows quantification of myocardial perfusion. The similarity between peripheral flow and myocardial perfusion is unclear. We compared perfusion flow in the myocardium with the upper limb during rest and adenosine stress [13N]ammonia PET to establish whether peripheral perfusion reserve (PPR) correlates with MPR.
  
  
  METHODS
  [13N]ammonia myocardial perfusion PET-scans of 58 patients were evaluated (27 men, 31 women, age 64 ± 13 years) and were divided in four subgroups: patients with coronary artery disease (CAD, n = 15), cardiac syndrome X (SX, n = 14), idiopathic dilating cardiomyopathy (DCM, n = 16), and normal controls (NC, n = 13). Peripheral limb perfusion was measured in the muscular tissue of the proximal upper limb and quantified through a 2-tissue-compartment model and the PPR was calculated (stress/rest ratio). MPR was also calculated by a 2-tissue-compartment model. The PPR results were compared with the MPR findings.
  
  
  RESULTS
  Mean myocardial perfusion increased significantly in all groups as evidenced by the MPR (CAD 1.99 ± 0.47; SX 1.39 ± 0.31; DCM 1.72 ± 0.69; NC 2.91 ± 0.78). Mean peripheral perfusion also increased but not significantly and accompanied with great variations within and between groups (mean PPR: CAD 1.30 ± 0.79; SX 1.36 ± 0.71; DCM 1.60 ± 1.22; NC 1.27 ± 0.63). The mean difference between PPR and MPR for all subpopulations varied widely. No significant correlations in flow reserve were found between peripheral and myocardial microcirculatory beds in any of the groups (Total group: r = -0.07, SEE = 0.70, CAD: r = 0.14, SEE = 0.48, SX: r = 0.17, SEE = 0.30, DCM: r = -0.11, SEE = 0.71, NC: r = -0.19, SEE = 0.80).
  
  
  CONCLUSIONS
  No correlations between myocardial and peripheral perfusion (reserve) were found in different patient populations in the same PET session. This suggests a functional difference between peripheral and myocardial flow in the response to intravenously administered adenosine stress.
authors.affiliation: Department of Imaging, University Medical Center Utrecht, E01.132, P.O. Box 85500, 3508GA Utrecht, The Netherlands. a.m.scholtens-2@umcutrecht.nl
authors.forename: A M
authors.initials: AM
authors.lastname: Scholtens
authors.forename: R A
authors.initials: RA
authors.lastname: Tio
authors.forename: A
authors.initials: A
authors.lastname: Willemsen
authors.forename: R A J O
authors.initials: RA
authors.lastname: Dierckx
authors.forename: H H
authors.initials: HH
authors.lastname: Boersma
authors.forename: C J
authors.initials: CJ
authors.lastname: Zeebregts
authors.forename: A W J M
authors.initials: AW
authors.lastname: Glaudemans
authors.forename: R H J A
authors.initials: RH
authors.lastname: Slart
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000641:Ammonia; D003326:Coronary Circulation; D005260:Female; D005542:Forearm / Q000098:blood supply*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D012039:Regional Blood Flow; D014664:Vasodilation / Q000187:drug effects
chemical_list: D000641:Ammonia; D000241:Adenosine