title: Myocardial Blood Flow and Flow Reserve in Proximal and Mid-to-Distal Lesions of Left Anterior Descending Artery Measured By N-13 Ammonia PET/CT.
abstract: OBJECTIVE
  The purpose of this study is to compare the myocardial blood flow (MBF) and flow reserve (MFR) between proximal and mid-to-distal lesions of the left anterior descending artery (pLAD and mdLAD, respectively) using N-13 ammonia positron emission tomography/computed tomography (PET/CT).
  
  
  METHODS
  Subjects were 11 patients (six men and five women, mean age 64.5 years) with known coronary artery disease (CAD) involving LAD studied by N-13 ammonia PET/CT. They were divided into two groups by the location of stenotic lesions, i.e. pLAD versus mdLAD. Global and regional MBF and MFR were measured and compared. Characteristics of perfusion defects including the number of involved segments, basal area involvement, location, size, and shape were also compared between the two groups.
  
  
  RESULTS
  The regional MFR in mid-anterior segment was significantly lower in pLAD group (1.80 ± 0.35 vs 2.76 ± 1.13 for pLAD and mdLAD groups, respectively, p = 0.034), while global MFR was not different (2.10 ± 1.10 vs 2.34 ± 0.84). Both stress and rest MBF in LAD territories were not different in both groups. The size of the perfusion defects were significantly larger in pLAD group (44.0 ± 11.5 % vs 21.1 ± 15.8 %, p = 0.041). Other characteristics such as location, basal area involvement, and shape were not significantly different between two groups.
  
  
  CONCLUSIONS
  The proximal lesion makes lower MFR in the mid-anterior segment and larger perfusion defect in the LAD territory but comparable MBF compared with mdLAD lesion.
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Hospital, Gwangju, South Korea.
authors.forename: Sang-Geon
authors.initials: SG
authors.lastname: Cho
authors.affiliation: Department of Cardiology, Chonnam National University Hospital, Gwangju, South Korea.
authors.forename: Ju Han
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Cardiology, Chonnam National University Hospital, Gwangju, South Korea.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Cho
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, 322 Seoyang-ro Hwasun-eup, Hwasun-gun, Jeonnam Korea 519-763.
authors.forename: Hyeon Sik
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, 322 Seoyang-ro Hwasun-eup, Hwasun-gun, Jeonnam Korea 519-763.
authors.forename: Hee-Seung
authors.initials: HS
authors.lastname: Bom
keywords: Left anterior descending artery; Myocardial blood flow; Myocardial flow reserve; N-13 ammonia positron emission tomography; Perfusion defect