Intracranial vascular stenosis and occlusion: comparison of 3D time-of-flight and 3D phase-contrast MR angiography

Neuroradiology. 1998 Sep;40(9):567-73. doi: 10.1007/s002340050645.


We compared the value of 3D time-of-flight (TOF) and phase-contrast (PC) MR angiography (MRA) for detection and grading of intracranial vascular steno-occlusive disease. Unenhanced 3D-TOF MRA and 3D-PC MRA (30-60 cm/s velocity encoding) were performed at the level of the circle of Willis in 18 patients, mean age 56 +/- 10 years. Postprocessed images using a maximum-intensity projection reconstruction with multiple targetted projections were analysed. A total of 126 vessels was assessed by PC MRA and 143 by TOF MRA, with digital subtraction angiography (DSA) in 15 patients and/or transcranial Doppler sonography (TCD) in 18 as a standard. Two blinded readers reviewed the MRA, DSA and TCD examinations retrospectively. On DSA and/or TCD the two observers found 32 and 28 steno-occlusive lesions. 3D-TOF MRA was more sensitive than 3D-PC MRA (87% and 86% vs. 65% and 60%) and had a higher negative predictive value (96% vs. 89%). Correct grading of stenoses was achieved in 78 % by 3D-TOF and 65% by 3D-PC MRA.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Brain Ischemia / diagnosis*
  • Circle of Willis / pathology
  • Female
  • Humans
  • Image Enhancement / instrumentation*
  • Image Processing, Computer-Assisted / instrumentation*
  • Magnetic Resonance Angiography / instrumentation*
  • Male
  • Middle Aged
  • Observer Variation
  • Sensitivity and Specificity
  • Ultrasonography, Doppler, Transcranial