title: Measurement of internal carotid artery stenosis from source MR angiograms.
abstract: OBJECTIVE
  To determine whether interpretation of internal carotid artery (ICA) stenosis from source partitions is more accurate than interpretation from maximum-intensity projections (MIPs) from three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography.
  
  
  METHODS
  The percentage of diameter ICA stenosis was measured on source images and MIPs from sagittal (n = 150) and transverse (n = 140) 3D TOF MR angiography. Measurements were compared with those from conventional angiography.
  
  
  RESULTS
  Sensitivity and specificity for distinguishing 70%-99% stenosis were 96% and 78%, respectively, for sagittal MIPs, 88% and 90% for sagittal source images, 92% and 86% for transverse MIPs, and 92% and 95% for transverse source images. Areas under the receiver operating characteristic curves statistically significantly increased (P < .05) with interpretation from source images. Complete loss of intravascular signal was not encountered on source partitions except within a greater than 85% stenosis.
  
  
  CONCLUSIONS
  Interpretation of source partitions rather than MIPs reduces the tendency for overestimation of stenosis with MR angiography and improves the specificity for discriminating 70%-99% stenosis.
authors.affiliation: Section of Radiology (114D), Veteran Affairs Medical Center, San Francisco, CA 94121.
authors.forename: C M
authors.initials: CM
authors.lastname: Anderson
authors.forename: R E
authors.initials: RE
authors.lastname: Lee
authors.forename: D L
authors.initials: DL
authors.lastname: Levin
authors.forename: S
authors.initials: S
authors.lastname: de la Torre Alonso
authors.forename: D
authors.initials: D
authors.lastname: Saloner
mesh_terms: D000368:Aged; D015901:Angiography, Digital Subtraction; D002343:Carotid Artery, Internal / Q000473:pathology; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000453:epidemiology; D017023:Coronary Angiography; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity