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

Abstract

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Surrogate vascular input function measurements from the superior sagittal sinus are repeatable and provide tissue-validated kinetic parameters in brain DCE-MRI

“…The 25 patients with GBM and 29 patients with sporadic VS were all imaged once on a 1.5 T scanner (Philips Achieva, Best, Netherlands). Thirteen of the included patients with GBM and twenty-two of the included patients with sporadic VS had been recruited and scanned as part of previous published studies at our institution 1 , 2 , 6 . The twelve patients with NF2-related VS had similarly been recruited as part of an earlier published study investigating bevacizumab (Avastin ©) related changes in DCE-MRI derived kinetic parameters in VS and these patients had been imaged twice at 1.5 T: pre-treatment (day 0) and 3 months (day 90) following bevacizumab (Avastin ©) treatment.…”

“…DCE-MRI data was acquired using a previously described DTR, dual injection technique 6 , 16 , 28 . Single dose macrocyclic GBCA (gadoterate meglumine; Dotarem, Guerbet S.A.) was used at a dose of 0.2 ml/kg.…”

“…As the second part of this DTR DCE-MRI technique, a full-dose of GBCA (dose = 0.2 ml/kg ·weight – dose of pre-bolus) was administered at the same rate (2 to 3 ml/s) as the pre-bolus (followed by a chaser of 20 ml of 0.9% saline administered at the same rate) during acquisition of a high-spatial resolution (FDHS) sequence 6 , 28 . FFT (Fast Fourier Transform) reconstruction in the z-direction was used for both the low-dose high temporal resolution (LDHT) and full-dose high spatial resolution (FDHS) acquisitions, doubling the number of slices 6 .…”

“…As the second part of this DTR DCE-MRI technique, a full-dose of GBCA (dose = 0.2 ml/kg ·weight – dose of pre-bolus) was administered at the same rate (2 to 3 ml/s) as the pre-bolus (followed by a chaser of 20 ml of 0.9% saline administered at the same rate) during acquisition of a high-spatial resolution (FDHS) sequence 6 , 28 . FFT (Fast Fourier Transform) reconstruction in the z-direction was used for both the low-dose high temporal resolution (LDHT) and full-dose high spatial resolution (FDHS) acquisitions, doubling the number of slices 6 . Variable flip-angle (VFA; α = 2°, 8°, 15° and 20°) acquisitions were undertaken prior to both the LDHT and FDHS DCE-MRI series for baseline longitudinal relaxation rate (R1 0 ) mapping, and the spatial resolution of each VFA acquisition series was chosen to match the LDHT and FDHS DCE series respectively 6 .…”

“…Dynamic contrast-enhanced (DCE) MRI has a developing role as an imaging tool for quantifying brain tumour microvasculature and tumour response to anti-angiogenic therapy 1 – 6 . In human clinical studies, non-invasive measurement of a suitable vascular input function (VIF) is essential for deriving microvascular kinetic parameters from brain DCE-MRI.…”