title: Manual or semi-automated edge detection of the maximal far wall common carotid intima-media thickness: a direct comparison.
abstract: BACKGROUND
  Automated edge detection is thought to be superior to manual edge detection in quantification of the far wall common carotid intima-media thickness (CIMT), yet published evidence making a direct comparison is not available.
  
  
  METHODS
  Data were used from the METEOR study, a randomized placebo-controlled trial among 984 individuals showing that rosuvastatin attenuated the rate of change of 2 year change in CIMT among low-risk individuals with subclinical atherosclerosis. For this post hoc analysis, CIMT images of the far wall of the common carotid artery were evaluated using manual and semi-automated edge detection and reproducibility, relation to cardiovascular risk factors, rates of change over time and effects of lipid-lowering therapy were assessed.
  
  
  RESULTS
  Reproducibility was high for both reading methods. Direction, magnitude and statistical significance of risk factor relations were similar across methods. Rate of change in CIMT in participants assigned to placebo was 0.0066 mm per year (SE: 0.0027) for manually and 0.0072 mm per year (SE: 0.0029) for semi-automatically read images. The effect of lipid-lowering therapy on CIMT changes was -0.0103 mm per year (SE: 0.0032) for manual reading and -0.0111 mm per year (SE: 0.0034) for semi-automated reading.
  
  
  CONCLUSIONS
  Manual and semi-automated readings of the maximal far wall of the common CIMT images both result in high reproducibility, show similar risk factor relations, rates of change and treatment effects. Hence, choices between semi-automated and manual reading software for CIMT studies likely should be based on logistical and cost considerations rather than differences in expected data quality when the choice is made to use far wall common CIMT measurements.
authors: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands. s.a.e.peters@umcutrecht.nl
authors: S A E
authors: SA
authors: Peters
authors: H M
authors: HM
authors: den Ruijter
authors: M K
authors: MK
authors: Palmer
authors: D E
authors: DE
authors: Grobbee
authors: J R
authors: JR
authors: Crouse
authors: D H
authors: DH
authors: O'Leary
authors: G W
authors: GW
authors: Evans
authors: J S
authors: JS
authors: Raichlen
authors: L
authors: L
authors: Lind
authors: M L
authors: ML
authors: Bots
mesh_terms: D000328:Adult; D050197:Atherosclerosis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D002339:Carotid Arteries / Q000187:drug effects*; D059168:Carotid Intima-Media Thickness / Q000295:instrumentation* / Q000592:standards; D018450:Disease Progression; D005260:Female; D005464:Fluorobenzenes / Q000627:therapeutic use; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011743:Pyrimidines / Q000627:therapeutic use; D015203:Reproducibility of Results; D012306:Risk; D000068718:Rosuvastatin Calcium; D013449:Sulfonamides / Q000627:therapeutic use; D013997:Time Factors; D017539:Tunica Intima / Q000187:drug effects*; D017540:Tunica Media / Q000187:drug effects*
chemical_list: D005464:Fluorobenzenes; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D011743:Pyrimidines; D013449:Sulfonamides; D000068718:Rosuvastatin Calcium