title: The time window of MRI of murine atherosclerotic plaques after administration of CB2 receptor targeted micelles: inter-scan variability and relation between plaque signal intensity increase and gadolinium content of inversion recovery prepared versus non-prepared fast spin echo.
abstract: Single fast spin echo scans covering limited time frames are mostly used for contrast-enhanced MRI of atherosclerotic plaque biomarkers. Knowledge on inter-scan variability of the normalized enhancement ratio of plaque (NER(plaque)) and relation between NER(plaque) and gadolinium content for inversion-recovery fast spin echo is limited. Study aims were: evaluation of (1) timing of MRI after intravenous injection of cannabinoid-2 receptor (CB2-R) (expressed by human and mouse plaque macrophages) targeted micelles; (2) inter-scan variability of inversion-recovery fast spin echo and fast spin echo; (3) relation between NER(plaque) and gadolinium content for inversion-recovery fast spin echo and fast spin echo. Inversion-recovery fast spin echo/fast spin echo imaging was performed before and every 15 min up to 48 h after injection of CB2-R targeted or control micelles using several groups of mice measured in an interleaved fashion. NER(plaque) (determined on inversion-recovery fast spin echo images) remained high (∼2) until 48 h after injection of CB2-R targeted micelles, whereas NER(plaque) decreased after 36 h in the control group. The inter-scan variability and relation between NER(plaque) and gadolinium (assessed with inductively coupled plasma- mass spectrometry) were compared between inversion-recovery fast spin echo and fast spin echo. Inter-scan variability was higher for inversion-recovery fast spin echo than for fast spin echo. Although gadolinium and NER(plaque) correlated well for both techniques, the NER of plaque was higher for inversion-recovery fast spin echo than for fast spin echo. In mice injected with CB2-R targeted micelles, NER(plaque) can be best evaluated at 36-48 h post-injection. Because NER(plaque) was higher for inversion-recovery fast spin echo than for fast spin echo, but with high inter-scan variability, repeated inversion-recovery fast spin echo imaging and averaging of the obtained NER(plaque) values is recommended.
authors.affiliation: Department of Cardiology, University Medical Center, Utrecht, The Netherlands. b.c.m.teboekhorst@umcutrecht.nl
authors.forename: B C M
authors.initials: BC
authors.lastname: te Boekhorst
authors.forename: S M
authors.initials: SM
authors.lastname: Bovens
authors.forename: C W A
authors.initials: CW
authors.lastname: van de Kolk
authors.forename: M J M
authors.initials: MJ
authors.lastname: Cramer
authors.forename: P A F M
authors.initials: PA
authors.lastname: Doevendans
authors.forename: M
authors.initials: M
authors.lastname: ten Hove
authors.forename: L
authors.initials: L
authors.lastname: van der Weerd
authors.forename: R
authors.initials: R
authors.lastname: Poelmann
authors.forename: G J
authors.initials: GJ
authors.lastname: Strijkers
authors.forename: G
authors.initials: G
authors.lastname: Pasterkamp
authors.forename: C J A
authors.initials: CJ
authors.lastname: van Echteld
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics; D015415:Biomarkers / Q000378:metabolism; D005682:Gadolinium / Q000378:metabolism*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D051379:Mice; D018345:Mice, Knockout; D008823:Micelles; D052250:Nitric Oxide Synthase Type III / Q000235:genetics; D058226:Plaque, Atherosclerotic / Q000378:metabolism / Q000473:pathology; D043885:Receptor, Cannabinoid, CB2 / Q000378:metabolism*; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D001057:Apolipoproteins E; D015415:Biomarkers; D008823:Micelles; D043885:Receptor, Cannabinoid, CB2; D005682:Gadolinium; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse