The LEGATOS technique: A new tissue‐validated dynamic contrast‐enhanced MRI method for whole‐brain, high‐spatial resolution parametric mapping

• Published in: Magnetic resonance in medicine Vol. 86; no. 4; pp. 2122 - 2136
• Main Authors: Li, Ka‐Loh, Lewis, Daniel, Coope, David J., Roncaroli, Federico, Agushi, Erjon, Pathmanaban, Omar N., King, Andrew T., Zhao, Sha, Jackson, Alan, Cootes, Timothy, Zhu, Xiaoping
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.10.2021
• Subjects: accurate kinetic parameter mapping; Brain; Brain mapping; Cell density; Contrast agents; Density; dual‐temporal resolution DCE‐MRI; Gadolinium; Glioblastoma; In vivo methods and tests; Magnetic resonance imaging; Markers; Microvasculature; Parameter estimation; perfusion and permeability; Pixels; Schwann cells; spatial and temporal resolution; Spatial discrimination; Spatial resolution; Temporal resolution; Tissues; Tumors; Vestibular system; spatial and temporal resolution; dual-temporal resolution DCE-MRI; perfusion and permeability; accurate kinetic parameter mapping
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.28842

Purpose A DCE‐MRI technique that can provide both high spatiotemporal resolution and whole‐brain coverage for quantitative microvascular analysis is highly desirable but currently challenging to achieve. In this study, we sought to develop and validate a novel dual‐temporal resolution (DTR) DCE‐MRI‐based methodology for deriving accurate, whole‐brain high‐spatial resolution microvascular parameters. Methods Dual injection DTR DCE‐MRI was performed and composite high‐temporal and high‐spatial resolution tissue gadolinium‐based‐contrast agent (GBCA) concentration curves were constructed. The high‐temporal but low‐spatial resolution first‐pass GBCA concentration curves were then reconstructed pixel‐by‐pixel to higher spatial resolution using a process we call LEGATOS. The accuracy of kinetic parameters (Ktrans, vp, and ve) derived using LEGATOS was evaluated through simulations and in vivo studies in 17 patients with vestibular schwannoma (VS) and 13 patients with glioblastoma (GBM). Tissue from 15 tumors (VS) was examined with markers for microvessels (CD31) and cell density (hematoxylin and eosin [H&E]). Results LEGATOS derived parameter maps offered superior spatial resolution and improved parameter accuracy compared to the use of high‐temporal resolution data alone, provided superior discrimination of plasma volume and vascular leakage effects compared to other high‐spatial resolution approaches, and correlated with tissue markers of vascularity (P ≤ 0.003) and cell density (P ≤ 0.006). Conclusion The LEGATOS method can be used to generate accurate, high‐spatial resolution microvascular parameter estimates from DCE‐MRI.