Evaluation of single bolus, dual-echo dynamic susceptibility contrast MRI protocols in brain tumor patients

Abstract

Relative cerebral blood volume (rCBV) obtained from dynamic susceptibility contrast (DSC) MRI is adversely impacted by contrast agent leakage in brain tumors. Using simulations, we previously demonstrated that multi-echo DSC-MRI protocols provide improvements in contrast agent dosing, pulse sequence flexibility, and rCBV accuracy. The purpose of this study is to assess the in-vivo performance of dual-echo acquisitions in patients with brain tumors (n = 59). To verify pulse sequence flexibility, four single-dose dual-echo acquisitions were tested with variations in contrast agent dose, flip angle, and repetition time, and the resulting dual-echo rCBV was compared to standard single-echo rCBV obtained with preload (double-dose). Dual-echo rCBV was comparable to standard double-dose single-echo protocols (mean (standard deviation) tumor rCBV 2.17 (1.28) vs. 2.06 (1.20), respectively). High rCBV similarity was observed (CCC = 0.96), which was maintained across both flip angle (CCC = 0.98) and repetition time (CCC = 0.96) permutations, demonstrating that dual-echo acquisitions provide flexibility in acquisition parameters. Furthermore, a single dual-echo acquisition was shown to enable quantification of both perfusion and permeability metrics. In conclusion, single-dose dual-echo acquisitions provide similar rCBV to standard double-dose single-echo acquisitions, suggesting contrast agent dose can be reduced while providing significant pulse sequence flexibility and complementary tumor perfusion and permeability metrics.

Identification of single-dose, dual-echo based CBV threshold for fractional tumor burden mapping in recurrent glioblastoma

“…The accuracy of the computed CBV maps derives from the reduction of T1 leakage effects, from the contrast agent preload, and T2* leakage effects using the BSW leakage correction algorithm ( 33 ). Similarly, dual-echo pulse sequences enable reliable CBV mapping with a single contrast agent dose through elimination of T1 leakage effects and mitigation of T2* effects using the BSW correction ( 30 , 34 ). This reduces the contrast agent dose, provides significant flexibility in pulse sequence parameters, and improves reproducibility by mitigating the variation in the preload dose and incubation time ( 30 ).…”

“…Similarly, dual-echo pulse sequences enable reliable CBV mapping with a single contrast agent dose through elimination of T1 leakage effects and mitigation of T2* effects using the BSW correction ( 30 , 34 ). This reduces the contrast agent dose, provides significant flexibility in pulse sequence parameters, and improves reproducibility by mitigating the variation in the preload dose and incubation time ( 30 ). In a study using a patient-based and validated DSC-MRI digital reference object (DRO), multi-echo acquisitions have shown more robust results than single-echo protocols as it essentially decouples both TR and FA from rCBV accuracy.…”

“…Residual T2* leakage effects can be removed using post-processing leakage correction algorithms. The validity of single-dose, dual-echo DSC-MRI protocols, and the derived rCBV maps, were recently validated by direct comparison to the standard double-dose, single-echo protocol ( 30 ). Favorably, the dual-echo approach decouples rCBV accuracy from pulse sequence parameters, enabling greater pulse sequence parameter flexibility and improved reproducibility ( 30 ).…”

“…The validity of single-dose, dual-echo DSC-MRI protocols, and the derived rCBV maps, were recently validated by direct comparison to the standard double-dose, single-echo protocol ( 30 ). Favorably, the dual-echo approach decouples rCBV accuracy from pulse sequence parameters, enabling greater pulse sequence parameter flexibility and improved reproducibility ( 30 ). While these studies demonstrated high accuracy for single-dose rCBV, there is a compelling need to further establish dual-echo DSC-MRI based FTB mapping to differentiate recurrent tumor and treatment effects.…”

Evaluation of postcontrast images of intracranial tumors at 7T and 3T MRI: An intra‐individual comparison study

“…16 In our study, the SNR and CNR in 7-T CE-MPRAGE images were significantly higher than those in 3-T images, which is due to the effect of contrast agent injection. 19,20 When the contrast agent reaches the tumor tissue, it shortens the longitudinal relaxation time of the tumor tissue and produces an MR signal different from that of normal brain tissue. 21 The relaxation rate r 1 of paramagnetic gadolinium-based contrast agents described by the Solomon-Bloembergen-Morgan equation becomes smaller with increasing field strength.…”