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Quantophyse: Tools - ASL Perfusion | Engineering Science Department - University of Oxford

Arterial Spin Labelling MRI Perfusion


Brain ultrasound image

Arterial Spin Labelling (ASL) is an MRI method for imaging the delivery of blood to body tissues, and is most widely used in the brain. By manipulating the the magnetization of blood water before entering the tissue the blood is labelled without the need to introduce a contrast agent.

Using ASL it is not only possible to generate perfusion-weighted images, but also make spatially resolved measurements of perfusion in absolute units (e.g., ml blood/100g tissue/min).

ASL Analysis in Quantiphyse 

Quantiphyse can perform all the main steps of ASL analysis:

  • Generation of perfusion-weighted image (label-control subtraction)
  • Kinetic modelling
  • Calculation of perfusion in absolute units (calibration)




Quantiphyse can process (almost) all varieties of ASL data:

  • CASL/pCASL (Continuous / Pseudo Continuous labelling)
  • PASL (pulsed labelling) including PICORE/Q2TIPS/QUIPSSII
  • Single and multiple post label delays (PLDs)
  • Multi-phase pCASL
  • 2D and 3D readout (EPI/GRASE etc)

Visualisation at the point of data setup is designed to help with complex data sets that combine different repeated measurements and PLDs

Advanced Options

Quantiphyse includes various advanced options:

  • Data scrubbing (ENABLE)
  • Distortion correction (requires fieldmap information)
  • Registration to structural image (requires FSL installation)
  • Bias correction for multiphase pCASL