Publications by authors named "L Petitclerc"
For better quantification of perfusion with arterial spin labeling (ASL), partial volume correction (PVC) is used to disentangle the signals from gray matter (GM) and white matter within any voxel. Based on physiological considerations, PVC algorithms typically assume zero signal in the cerebrospinal fluid (CSF). Recent measurements, however, have shown that CSF-ASL signal can exceed 10% of GM signal, even when using recommended ASL labeling parameters.
View Article and Find Full Text PDFArticle Synopsis
- - The research focuses on how the brain clears waste products, particularly the role of cerebrospinal fluid (CSF) in this mechanism, which is still not fully understood.
- - A new MRI technique, modified arterial spin labeling (ASL), was developed to better study the movement of water from blood to CSF and its exchange process.
- - The study findings suggest that labeled water is detected in both CSF near the choroid plexus and surrounding the cortex, with an estimated exchange time from blood to CSF of around 60 seconds.
Purpose: Arterial spin labeling can be used to assess the transition time of water molecules across the blood-brain barrier when combined with sequence modules, which allow a separation of intravascular from tissue signal. The bipolar gradient technique measures the intravascular fraction by removing flowing spins. The T -relaxation-under-spin-tagging (TRUST) technique modulates the TE to differentiate between intravascular and extravascular spins based on T .
View Article and Find Full Text PDFBackground: MR elastography is a noninvasive technique that provides high diagnostic accuracy for the staging of liver fibrosis; however, it requires external hardware and mainly assesses the right lobe.
Purpose: To evaluate the diagnostic performance of MRI cine-tagging for staging fibrosis in the left liver lobe, using biopsy as the reference standard.
Study Type: Institutional Review Board (IRB)-approved two-center prospective study.
Purpose: To identify quantitative dynamic contrast-enhanced (DCE)-MRI perfusion parameters indicating tumor response of hepatocellular carcinoma (HCC) to transarterial chemoembolization (TACE).
Materials And Methods: This prospective pilot study was approved by our institutional review board; written and informed consent was obtained for each participant. Patients underwent DCE-MRI examinations before and after TACE.