Emelie Lindgren1, Linda Knutsson1, Danielle van Westen2,3, Karin Markenroth Bloch4, Freddy Sthlberg1,3, Ronnie Wirestam1
1Department of Medical Radiation Physics, Lund University, Lund, Sweden; 2Center for Medical Imaging and Physiology, Lund University Hospital, Lund, Sweden; 3Department of Diagnostic Radiology, Lund University, Lund, Sweden; 4Philips Medical Systems, Lund, Sweden
The phase shift during a contrast-agent bolus passage is assumed to be proportional to the concentration of contrast agent. In this study, phase-shift curves in tissue and artery were registered and a phase-based perfusion index and grey-matter MTT were calculated. The relationship between the phase-based perfusion index and ASL CBF estimates showed good linear correlation (r=0.81). The mean grey-matter MTT was 5.4 s, consistent with literature values. Phase-based absolute quantification of CBF is difficult, but the use of a phase-based perfusion index for rescaling of DSC-MRI results can potentially be of value to achieve more robust and reproducible DSC-MRI estimates.