Generalized q-sampling imaging fiber tractography reveals displacement and infiltration of fiber tracts in low-grade gliomas
- 253 Downloads
Low-grade gliomas (LGGs) are slow growing brain tumors that often cause displacement and/or infiltration of the surrounding white matter pathways. Differentiation between infiltration and displacement of fiber tracts remains a challenge. Currently, there is no reliable noninvasive imaging method capable of revealing such white matter alteration patterns. We employed quantitative anisotropy (QA) derived from generalized q-sampling imaging (GQI) to identify patterns of fiber tract alterations by LGGs.
Sixteen patients with a neuropathological diagnosis of LGG (WHO grade II) were enrolled. Peritumoral fiber tracts underwent qualitative and quantitative evaluation. Contralateral hemisphere counterparts were used for comparison. Tracts were qualitatively classified as unaffected, displaced, infiltrated or displaced, and infiltrated at once. The average QA of whole tract (W), peritumoral tract segment (S), and their ratio (S/W) were obtained and compared to the healthy side for quantitative evaluation.
Qualitative analysis revealed 9 (13.8%) unaffected, 24 (36.9%) displaced, 13 (20%) infiltrated, and 19 (29.2%) tracts with a combination of displacement and infiltration. There were no disrupted tracts. There was a significant increase in S/W ratio among displaced tracts in the pre-operative scans in comparison with the contralateral side. QA values of peritumoral tract segments (S) were significantly lower in infiltrated tracts.
WHO grade II LGGs might displace, infiltrate, or cause a combination of displacement and infiltration of WM tracts. QA derived from GQI provides valuable information that helps to differentiate infiltration from displacement. Anisotropy changes correlate with qualitative alterations, which may serve as a potential biomarker of fiber tract integrity.
KeywordsDiffusion magnetic resonance imaging Fiber tractography Low-grade glioma Quantitative anisotropy White matter
The authors would like to acknowledge the contribution of Yue-Fang Chang, Ph.D., in providing statistical analyses.
Compliance with ethical standards
This research was funded by a Seed Grant from the University of Pittsburgh Brain Institute and was partly funded by the Walter L. Copeland Fund of the Pittsburgh Foundation for Cranial Research.
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. For this type of study formal consent is not required.
For this type of retrospective study formal consent is not required.
- 5.Berger MS, Deliganis AV, Dobbins J, Keles GE (1994) The effect of extent of resection on recurrence in patients with low grade cerebral hemisphere gliomas. Cancer 74(6):1784–1791. https://doi.org/10.1002/1097-0142(19940915)74:6<1784::AID-CNCR2820740622>3.0.CO;2-D CrossRefPubMedGoogle Scholar
- 8.Smith JS, Chang EF, Lamborn KR, Chang SM, Prados MD, Cha S, Tihan T, VandenBerg S, McDermott MW, Berger MS (2008) Role of extent of resection in the long-term outcome of low-grade hemispheric gliomas. J Clin Oncol 26(8):1338–1345. https://doi.org/10.1200/JCO.2007.13.9337 CrossRefPubMedGoogle Scholar
- 9.Ius T, Isola M, Budai R et al (2012) Low-grade glioma surgery in eloquent areas: volumetric analysis of extent of resection and its impact on overall survival. A single-institution experience in 190 patients: clinical article. J Neurosurg 117(6):1039–1052. https://doi.org/10.3171/2012.8.JNS12393 CrossRefPubMedGoogle Scholar
- 26.Delgado AF, Nilsson M, Latini F, Mårtensson J, Zetterling M, Berntsson SG, Alafuzoff I, Lätt J, Larsson EM (2016) Preoperative quantitative MR tractography compared with visual tract evaluation in patients with neuropathologically confirmed gliomas grades II and III: a prospective cohort study. Radiol Res Pract 2016:7671854–7671815. https://doi.org/10.1155/2016/7671854 PubMedPubMedCentralGoogle Scholar
- 27.Zhang H, Wang Y, Lu T, Qiu B, Tang Y, Ou S, Tie X, Sun C, Xu K, Wang Y (2013) Differences between generalized q-sampling imaging and diffusion tensor imaging in the preoperative visualization of the nerve fiber tracts within peritumoral edema in brain. Neurosurgery 73(6):1044–1053; discussion 1053. https://doi.org/10.1227/NEU.0000000000000146 CrossRefPubMedGoogle Scholar
- 30.Abhinav K, Pathak S, Richardson RM, Engh J, Gardner P, Yeh FC, Friedlander RM, Fernandez-Miranda JC (2014) Application of high-definition fiber tractography in the management of supratentorial cavernous malformations: a combined qualitative and quantitative approach. Neurosurgery 74(6):668–680; discussion 680-681. https://doi.org/10.1227/NEU.0000000000000336 CrossRefPubMedGoogle Scholar
- 31.Fernandes-Cabral DT, Zenonos GA, Hamilton RL, Panesar SS, Fernandez-Miranda JC (2016) High-definition fiber tractography in the evaluation and surgical planning of Lhermitte-Duclos disease: a case report. World Neurosurg 92:587.e9–587.e13. https://doi.org/10.1016/j.wneu.2016.04.128 CrossRefGoogle Scholar
- 37.Akai H, Mori H, Aoki S et al (2005) Diffusion tensor tractography of gliomatosis cerebri: fiber tracking through the tumor. J Comput Assist Tomogr 29(1):127–129. https://doi.org/10.1097/01.rct.0000148453.29579.51 CrossRefPubMedGoogle Scholar