A fast protocol for multicenter and multiparametric quantitative MRI studies in brain tumor patients using vendor sequences

Abstract Background Multiparametric quantitative MRI (mp-qMRI) provides noninvasive, quantitative measurements sensitive to a variety of tissue properties. In brain tumors (BTs), longitudinal relaxation time (T1), effective transverse relaxation time (T2*), transverse relaxation time (T2), water content (H2O), and quantitative susceptibility (χ) give valuable insights into the microenvironment. To generate large multicenter datasets, protocols need to be short and implementable on any scanner. The goal of this work was to develop and validate an 8-min, 3T mp-qMRI protocol for BT patients solely using generalized pulse sequences (mGRE and EPI). Methods A protocol was developed and tested on a multicompartment phantom, 5 healthy subjects (mean age: 31.64 years), and 4 BT patients (mean age:39.5 years). Phantom and healthy subject longitudinal relaxation time (T1) maps were compared to those obtained using 2 reference methods. The 5 healthy subjects were scanned on 3T MRI scanners at 2 different sites and the reproducibility between scanners was assessed by computing Coefficients of Variance (COV) maps, performing Bland–Altman analysis and t-tests. Clinical feasibility was tested on 4 BT patients. Results T1 values obtained using the proposed mp-qMRI protocol agree with those obtained using the reference methods in volunteers (mean error = 8.94 ms). The qMRI maps (T1, T2*, H2O, and χ) of the volunteers showed good reproducibility between scanners with no significant differences for mean WM and GM qMRI values. WM and GM mean qMRI values agreed well with literature values. H2O gave the lowest COV and χ maps the highest. Conclusion The proposed vendor sequence-based 3T mp-qMRI protocol gives interpolated, high resolution (1 mm isotropic) T1, T2*, H2O, and χ maps in 8 min of acquisition. Lay Summary Patients with brain tumors often need MRIs. New methods, called quantitative-MRI methods, provide very valuable and unique information in brain tumors, but can take up to 30 min of additional MRI scanning. The authors of this study wanted to develop a shorter-duration quantitative-MRI method that could be used in the clinic without affecting the quality of results. To do this they created a new 8-min quantitative-MRI method that measures different properties of brain tissue. They tested the new method on 5 healthy subjects and 4 patients with brain tumors, using different MRI machines. Their results showed that the shorter quantitative-MRI method provided detailed, go