The QUASAR reproducibility study, Part II: Results from a multi-center Arterial Spin Labeling test-retest study

Esben Thade Petersen, Kim Mouridsen, Xavier Golay, all named co-authors of the QUASAR test-retest study (Linda Knutsson)

Research output: Contribution to journalArticlepeer-review


Arterial Spin Labeling (ASL) is a method to measure perfusion using magnetically labeled blood water as an endogenous tracer. Being fully non-invasive, this technique is attractive for longitudinal studies of cerebral blood flow in healthy and diseased individuals, or as a surrogate marker of metabolism. So far, ASL has been restricted mostly to specialist centers due to a generally low SNR of the method and potential issues with user-dependent analysis needed to obtain quantitative measurement of cerebral blood flow (CBF). Here, we evaluated a particular implementation of ASL (called Quantitative STAR labeling of Arterial Regions or QUASAR), a method providing user independent quantification of CBF in a large test-retest study across sites from around the world, dubbed "The QUASAR reproducibility study". Altogether, 28 sites located in Asia, Europe and North America participated and a total of 284 healthy volunteers were scanned. Minimal operator dependence was assured by using an automatic planning tool and its accuracy and potential usefulness in multi-center trials was evaluated as well. Accurate repositioning between sessions was achieved with the automatic planning tool showing mean displacements of 1.87+/-0.95 mm and rotations of 1.56+/-0.66 degrees . Mean gray matter CBF was 47.4+/-7.5 [ml/100 g/min] with a between-subject standard variation SD(b)=5.5 [ml/100 g/min] and a within-subject standard deviation SD(w)=4.7 [ml/100 g/min]. The corresponding repeatability was 13.0 [ml/100 g/min] and was found to be within the range of previous studies.

Original languageEnglish
Pages (from-to)104-13
Number of pages10
Issue number1
Publication statusPublished - 2010 Jan 1
Externally publishedYes

Free keywords

  • Adolescent
  • Adult
  • Aged
  • Blood Volume
  • Brain Mapping
  • Cerebral Arteries
  • Cerebrovascular Circulation
  • Female
  • Humans
  • Male
  • Middle Aged
  • Reproducibility of Results
  • Software
  • Spin Labels
  • Young Adult


Dive into the research topics of 'The QUASAR reproducibility study, Part II: Results from a multi-center Arterial Spin Labeling test-retest study'. Together they form a unique fingerprint.

Cite this