Optimization of DSC MRI Echo Times for CBV Measurements Using Error Analysis in a Pilot Study of High-Grade Gliomas

Bell, Laura C.; Does, Mark D.; Stokes, Ashley M.; Baxter, Leslie C.; Schmainda, Kathleen M.; Dueck, Amylou C.; Quarles, C. Chad

doi:10.3174/ajnr.a5295

Cited by 11 publications

(11 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies have shown that the AIF is adversely impacted by concurrent T 1 effects, which can substantially reduce the resulting CBF measures (up to 40%) . In addition, the optimal TE for measuring the AIF was previously estimated to be 12 ms, which is far shorter than both the typical DSC‐MRI protocol and the reported optimal tumor TE (30 ms) . Multi‐echo sequences may permit the optimization of individual echoes for AIF and tissue, particularly when at least 1 TE is less than 15 ms.…”

Section: Discussionmentioning

confidence: 99%

“…38 In addition, the optimal TE for measuring the AIF was previously estimated to be 12 ms, which is far shorter than both the typical DSC-MRI protocol and the reported optimal tumor TE (30 ms). 39 Multi-echo sequences may permit the optimization of individual echoes for AIF and tissue, particularly when at least 1 TE is less than 15 ms. Finally, the correlation between individual echoes in multi-echo protocols may serve as a unique criterion to improve automated AIF selection.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Systematic assessment of multi‐echo dynamic susceptibility contrast MRI using a digital reference object

Stokes

Semmineh

Nespodzany

et al. 2019

Magnetic Resonance in Med

Self Cite

View full text Add to dashboard Cite

Purpose Brain tumor dynamic susceptibility contrast (DSC) MRI is adversely impacted by T1 and T2∗ contrast agent leakage effects that result in inaccurate hemodynamic metrics. While multi‐echo acquisitions remove T1 leakage effects, there is no consensus on the optimal set of acquisition parameters. Using a computational approach, we systematically evaluated a wide range of acquisition strategies to determine the optimal multi‐echo DSC‐MRI perfusion protocol. Methods Using a population‐based DSC‐MRI digital reference object (DRO), we assessed the influence of preload dosing (no preload and full dose preload), field strength (1.5 and 3T), pulse sequence parameters (echo time, repetition time, and flip angle), and leakage correction on relative cerebral blood volume (rCBV) and flow (rCBF) accuracy. We also compared multi‐echo DSC‐MRI protocols with standard single‐echo protocols. Results Multi‐echo DSC‐MRI is highly consistent across all protocols, and multi‐echo rCBV (with or without use of a preload dose) had higher accuracy than single‐echo rCBV. Regression analysis showed that choice of repetition time and flip angle had minimal impact on multi‐echo rCBV and rCBV, indicating the potential for significant flexibility in acquisition parameters. The echo time combination had minimal impact on rCBV, though longer echo times should be avoided, particularly at higher field strengths. Leakage correction improved rCBV accuracy in all cases. Multi‐echo rCBF was less biased than single‐echo rCBF, although rCBF accuracy was reduced overall relative to rCBV. Conclusions Multi‐echo acquisitions were more robust than single‐echo, essentially decoupling both repetition time and flip angle from rCBV accuracy. Multi‐echo acquisitions obviate the need for preload dosing, although leakage correction to remove residual T2∗ leakage effects remains compulsory for high rCBV accuracy.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Systematic assessment of multi‐echo dynamic susceptibility contrast MRI using a digital reference object

Stokes

Semmineh

Nespodzany

et al. 2019

Magnetic Resonance in Med

Self Cite

View full text Add to dashboard Cite

show abstract

“…To balance these effects, the typical recommendation for TE is 25-35 ms. Using rCBV error minimization as a metric for TE optimization, the optimal TE is equal to a weighted average of the changes in tissue T 2 * during contrast agent passage (Bell et al, 2017a;Boxerman et al, 1997;Thilmann et al, 2004). Due to the bolus-induced signal drop, this is lower than the baseline T 2 *…”

Section: Pulse Sequencesmentioning

confidence: 99%

“…The simplest of these options is a dual GRE, where an additional short-TE echo is acquired between the excitation pulse and the traditional longer-TE echo. This method also provides more flexibility in the TEs, which may improve characterization of both the AIF (using an optimized shorter TE) and brain tissue (Bell et al, 2017a;Newton et al, 2016). Perhaps more importantly, T 1 leakage effects can be quantified, permitting both direct DCE-MRI analysis and correction of DSC-MRI data for more accurate perfusion analysis (Quarles et al, 2012;Sourbron et al, 2009;Stokes et al, 2016a).…”

Section: Pulse Sequencesmentioning

confidence: 99%

Imaging vascular and hemodynamic features of the brain using dynamic susceptibility contrast and dynamic contrast enhanced MRI

2019

View full text Add to dashboard Cite

In the context of neurologic disorders, dynamic susceptibility contrast (DSC) and dynamic contrast enhanced (DCE) MRI provide valuable insights into cerebral vascular function, integrity, and architecture. Even after two decades of use, these modalities continue to evolve as their biophysical and kinetic basis is better understood, with improvements in pulse sequences and accelerated imaging techniques and through application of more robust and automated data analysis strategies. Here, we systematically review each of these elements, with a focus on how their integration improves kinetic parameter accuracy and the development of new hemodynamic biomarkers that provide sub-voxel sensitivity (e.g., capillary transit time and flow heterogeneity). Regarding contrast mechanisms, we discuss the dipole-dipole interactions and susceptibility effects that give rise to simultaneous T, T and T relaxation effects, including their quantification, influence on pulse sequence parameter optimization, and use in methods such as vessel size and vessel architectural imaging. The application of technologic advancements, such as parallel imaging, simultaneous multi-slice, undersampled k-space acquisitions, and sliding window strategies, enables improved spatial and/or temporal resolution of DSC and DCE acquisitions. Such acceleration techniques have also enabled the implementation of, clinically feasible, simultaneous multi-echo spin- and gradient echo acquisitions, providing more comprehensive and quantitative interrogation of T, T and T changes. Characterizing these relaxation rate changes through different post-processing options allows for the quantification of hemodynamics and vascular permeability. The application of different biophysical models provides insight into traditional hemodynamic parameters (e.g., cerebral blood volume) and more advanced parameters (e.g., capillary transit time heterogeneity). We provide insight into the appropriate selection of biophysical models and the necessary post-processing steps to ensure reliable measurements while minimizing potential sources of error. We show representative examples of advanced DSC- and DCE-MRI methods applied to pathologic conditions affecting the cerebral microcirculation, including brain tumors, stroke, aging, and multiple sclerosis. The maturation and standardization of conventional DSC- and DCE-MRI techniques has enabled their increased integration into clinical practice and use in clinical trials, which has, in turn, spurred renewed interest in their technological and biophysical development, paving the way towards a more comprehensive assessment of cerebral hemodynamics.

show abstract

“…As NAWM ROIs are conventionally drawn contralateral to tumor tissue, we selected the contralateral mask hemisphere. Additional details of these postprocessing steps can be found in previous publications …”

Section: Methodsmentioning

confidence: 99%

Analysis of postprocessing steps for residue function dependent dynamic susceptibility contrast (DSC)‐MRI biomarkers and their clinical impact on glioma grading for both 1.5 and 3T

Bell

Stokes

Quarles

2019

Magnetic Resonance Imaging

Self Cite

View full text Add to dashboard Cite

Background Dynamic susceptibility contrast (DSC)‐MRI analysis pipelines differ across studies and sites, potentially confounding the clinical value and use of the derived biomarkers. Purpose/Hypothesis To investigate how postprocessing steps for computation of cerebral blood volume (CBV) and residue function dependent parameters (cerebral blood flow [CBF], mean transit time [MTT], capillary transit heterogeneity [CTH]) impact glioma grading. Study Type Retrospective study from The Cancer Imaging Archive (TCIA). Population Forty‐nine subjects with low‐ and high‐grade gliomas. Field Strength/Sequence 1.5 and 3.0T clinical systems using a single‐echo echo planar imaging (EPI) acquisition. Assessment Manual regions of interest (ROIs) were provided by TCIA and automatically segmented ROIs were generated by k‐means clustering. CBV was calculated based on conventional equations. Residue function dependent biomarkers (CBF, MTT, CTH) were found by two deconvolution methods: circular discretization followed by a signal‐to‐noise ratio (SNR)‐adapted eigenvalue thresholding (Method 1) and Volterra discretization with L‐curve‐based Tikhonov regularization (Method 2). Statistical Tests Analysis of variance, receiver operating characteristics (ROC), and logistic regression tests. Results MTT alone was unable to statistically differentiate glioma grade (P > 0.139). When normalized, tumor CBF, CTH, and CBV did not differ across field strengths (P > 0.141). Biomarkers normalized to automatically segmented regions performed equally (rCTH AUROC is 0.73 compared with 0.74) or better (rCBF AUROC increases from 0.74–0.84; rCBV AUROC increases 0.78–0.86) than manually drawn ROIs. By updating the current deconvolution steps (Method 2), rCTH can act as a classifier for glioma grade (P < 0.007), but not if processed by current conventional DSC methods (Method 1) (P > 0.577). Lastly, higher‐order biomarkers (eg, rCBF and rCTH) along with rCBV increases AUROC to 0.92 for differentiating tumor grade as compared with 0.78 and 0.86 (manual and automatic reference regions, respectively) for rCBV alone. Data Conclusion With optimized analysis pipelines, higher‐order perfusion biomarkers (rCBF and rCTH) improve glioma grading as compared with CBV alone. Additionally, postprocessing steps impact thresholds needed for glioma grading. Level of Evidence: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:547–553.

show abstract

Optimization of DSC MRI Echo Times for CBV Measurements Using Error Analysis in a Pilot Study of High-Grade Gliomas

Cited by 11 publications

References 21 publications

Systematic assessment of multi‐echo dynamic susceptibility contrast MRI using a digital reference object

Systematic assessment of multi‐echo dynamic susceptibility contrast MRI using a digital reference object

Imaging vascular and hemodynamic features of the brain using dynamic susceptibility contrast and dynamic contrast enhanced MRI

Analysis of postprocessing steps for residue function dependent dynamic susceptibility contrast (DSC)‐MRI biomarkers and their clinical impact on glioma grading for both 1.5 and 3T

Contact Info

Product

Resources

About