Differences Between Generalized Q-Sampling Imaging and Diffusion Tensor Imaging in the Preoperative Visualization of the Nerve Fiber Tracts Within Peritumoral Edema in Brain

Zhang, Hongliang; Wang, Yong; Lü, Tao; Qiu, Bo; Tang, Yanqing; Ou, Shaowu; Tie, Xinxin; Sun, Chuanqi; Xu, Ke; Wang, Yibao

doi:10.1227/neu.0000000000000146

Cited by 80 publications

(79 citation statements)

References 25 publications

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“…Some groups also attempted to address this challenge in the imaging/scanner level with other fiber orientation estimation/modeling methods. Zhang et al (2013) compared generalized q-sampling based tractography with DTI-based WM mapping in edematous regions. They demonstrated that DTI-based tractography missed several fiber tracts in 5 cases in comparison with those from generalized q-sampling imaging (GQI) data.…”

Section: Discussionmentioning

confidence: 99%

Performance of unscented Kalman filter tractography in edema: Analysis of the two-tensor model

Liao

Ning

Chen

et al. 2017

NeuroImage: Clinical

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Diffusion MRI tractography is increasingly used in pre-operative neurosurgical planning to visualize critical fiber tracts. However, a major challenge for conventional tractography, especially in patients with brain tumors, is tracing fiber tracts that are affected by vasogenic edema, which increases water content in the tissue and lowers diffusion anisotropy. One strategy for improving fiber tracking is to use a tractography method that is more sensitive than the traditional single-tensor streamline tractography.We performed experiments to assess the performance of two-tensor unscented Kalman filter (UKF) tractography in edema. UKF tractography fits a diffusion model to the data during fiber tracking, taking advantage of prior information from the previous step along the fiber. We studied UKF performance in a synthetic diffusion MRI digital phantom with simulated edema and in retrospective data from two neurosurgical patients with edema affecting the arcuate fasciculus and corticospinal tracts. We compared the performance of several tractography methods including traditional streamline, UKF single-tensor, and UKF two-tensor. To provide practical guidance on how the UKF method could be employed, we evaluated the impact of using various seed regions both inside and outside the edematous regions, as well as the impact of parameter settings on the tractography sensitivity. We quantified the sensitivity of different methods by measuring the percentage of the patient-specific fMRI activation that was reached by the tractography.We expected that diffusion anisotropy threshold parameters, as well as the inclusion of a free water model, would significantly influence the reconstruction of edematous WM fiber tracts, because edema increases water content in the tissue and lowers anisotropy. Contrary to our initial expectations, varying the fractional anisotropy threshold and including a free water model did not affect the UKF two-tensor tractography output appreciably in these two patient datasets. The most effective parameter for increasing tracking sensitivity was the generalized anisotropy (GA) threshold, which increased the length of tracked fibers when reduced to 0.075. In addition, the most effective seeding strategy was seeding in the whole brain or in a large region outside of the edema.Overall, the main contribution of this study is to provide insight into how UKF tractography can work, using a two-tensor model, to begin to address the challenge of fiber tract reconstruction in edematous regions near brain tumors.

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Section: Discussionmentioning

confidence: 99%

Performance of unscented Kalman filter tractography in edema: Analysis of the two-tensor model

Liao

Ning

Chen

et al. 2017

NeuroImage: Clinical

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“…As we demonstrated in our study, clinical diffusion data of around 30 directions at a b-value of 1000 s/mm 2 is adequate for two-tensor UKF tractography. Another study by Zhang et al [27] showed that generalized q-sampling imaging can visualize the tracts in the peritumoral edema of cerebral tumors better than DTI. McDonald et al [28] also demonstrated that restriction spectrum imaging can be used to improve the quantification and visualization of white matter tracts in regions of peritumoral edema.…”

Section: Discussionmentioning

confidence: 99%

Corticospinal tract modeling for neurosurgical planning by tracking through regions of peritumoral edema and crossing fibers using two-tensor unscented Kalman filter tractography

et al. 2016

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Purpose The aim of this study was to present a tractography algorithm using a two-tensor unscented Kalman filter (UKF) to improve the modeling of the corticospinal tract (CST) by tracking through regions of peritumoral edema and crossing fibers. Methods Ten patients with brain tumors in the vicinity of motor cortex and evidence of significant peritumoral edema were retrospectively selected for the study. All patients underwent 3-Tesla magnetic resonance imaging (MRI) including functional MRI (fMRI) and a diffusion-weighted data set with 31 directions. Fiber tracking was performed using both single-tensor streamline and two-tensor UKF tractography methods. A two-regions-of-interest approach was used to delineate the CST. Results from the two tractography methods were compared visually and quantitatively. fMRI was applied to identify the functional fiber tracts. Results Single-tensor streamline tractography underestimated the extent of tracts running through the edematous areas and could only track the medial projections of the CST. In contrast, two-tensor UKF tractography tracked fanning projections of the CST despite peritumoral edema and crossing fibers. The two-tensor UKF tractography delineated tracts that were closer to motor fMRI activations, and it was more sensitive than single-tensor streamline tractography to define the tracts directed to the motor sites. The volume of the CST was significantly larger on two-tensor UKF than on single-tensor streamline tractography (p < 0.001). Conclusions Two-tensor UKF tractography tracks the CST better than single-tensor streamline tractography in the setting of peritumoral edema and crossing fibers in brain tumor patients.

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“…In the setting of mass lesions, an abnormal trajectory of a fiber may be either technical in origin or real. 1,23 Despite the improved ability of the advanced techniques 22,50 to depict white matter tracts in the perilesional edematous zone, a careful interpretation of the qualitative data should be carried out with a sound knowledge of the loco-regional neuroanatomy to facilitate safer surgical planning. Relevant to the quantitative analysis in the longitudinal studies is the variability in the parameters, such as QA, that can occur across the scanning sessions.…”

Section: Tractography Versus Diffusion Connectometry Approach: Generamentioning

confidence: 99%

Longitudinal evaluation of corticospinal tract in patients with resected brainstem cavernous malformations using high-definition fiber tractography and diffusion connectometry analysis: preliminary experience

Faraji¹,

Kumar²,

Jarbo

et al. 2015

JNS

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abbreviatioNs ADL = activities of daily living; CC = corpus callosum; CM = cavernous malformation; CN = cranial nerve; CST = corticospinal tract; DSI = diffusion spectrum imaging; DTI = diffusion tensor imaging; FDR = false discovery rate; HDFT = high-definition fiber tractography; ICH = intracerebral hemorrhage; QA = quantitative anisotropy; ROI = region of interest; SRS = stereotactic radiosurgery. obJect Brainstem cavernous malformations (CMs) are challenging due to a higher symptomatic hemorrhage rate and potential morbidity associated with their resection. The authors aimed to preoperatively define the relationship of CMs to the perilesional corticospinal tracts (CSTs) by obtaining qualitative and quantitative data using high-definition fiber tractography. These data were examined postoperatively by using longitudinal scans and in relation to patients' symptomatology. The extent of involvement of the CST was further evaluated longitudinally using the automated "diffusion connectometry" analysis. methods Fiber tractography was performed with DSI Studio using a quantitative anisotropy (QA)-based generalized deterministic tracking algorithm. Qualitatively, CST was classified as being "disrupted" and/or "displaced." Quantitative analysis involved obtaining mean QA values for the CST and its perilesional and nonperilesional segments. The contralateral CST was used for comparison. Diffusion connectometry analysis included comparison of patients' data with a template from 90 normal subjects. results Three patients (mean age 22 years) with symptomatic pontomesencephalic hemorrhagic CMs and varying degrees of hemiparesis were identified. The mean follow-up period was 37.3 months. Qualitatively, CST was partially disrupted and displaced in all. Direction of the displacement was different in each case and progressively improved corresponding with the patient's neurological status. No patient experienced neurological decline related to the resection. The perilesional mean QA percentage decreases supported tract disruption and decreased further over the follow-up period (Case 1, 26%-49%; Case 2, 35%-66%; and Case 3, 63%-78%). Diffusion connectometry demonstrated rostrocaudal involvement of the CST consistent with the quantitative data. coNclusioNs Hemorrhagic brainstem CMs can disrupt and displace perilesional white matter tracts with the latter occurring in unpredictable directions. This requires the use of tractography to accurately define their orientation to optimize surgical entry point, minimize morbidity, and enhance neurological outcomes. Observed anisotropy decreases in the perilesional segments are consistent with neural injury following hemorrhagic insults. A model using these values in different CST segments can be used to longitudinally monitor its craniocaudal integrity. Diffusion connectometry is a complementary approach providing longitudinal information on the rostrocaudal involvement of the CST.

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Differences Between Generalized Q-Sampling Imaging and Diffusion Tensor Imaging in the Preoperative Visualization of the Nerve Fiber Tracts Within Peritumoral Edema in Brain

Abstract: GQI can visualize the tracts in the peritumoral edema of cerebral tumors better than DTI. Although GQI has many limitations, its future in the preoperative guidance of brain tumor lesions is promising.

Cited by 80 publications

References 25 publications

Performance of unscented Kalman filter tractography in edema: Analysis of the two-tensor model

Performance of unscented Kalman filter tractography in edema: Analysis of the two-tensor model

Corticospinal tract modeling for neurosurgical planning by tracking through regions of peritumoral edema and crossing fibers using two-tensor unscented Kalman filter tractography

Longitudinal evaluation of corticospinal tract in patients with resected brainstem cavernous malformations using high-definition fiber tractography and diffusion connectometry analysis: preliminary experience

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