CASE 13254 Published on 26.01.2016

The importance of fMRI and DTI in the presurgical planning of multicentric low-grade gliomas: a case report.

Section

Neuroradiology

Case Type

Clinical Cases

Authors

K. Beka¹, D. Verganelakis², P. Toulas², N. Georgakoulias³, A. Gouliamos¹

¹1st Department of Radiology, University of Athens, Aretaieion Hospital, Athens, Greece;
²Depatment of MR Imaging, Advanced Diagnostic and Research Institute «Euromedica-Encephalos», Athens, Greece
³Department of Neurosurgery, Athens General Hospital G.Gennimatas, Athens, Greece
Email:kbekaath@yahoo.gr

Patient

18 years, male

Categories

Area of Interest Neuroradiology brain ; Imaging Technique MR, MR-Diffusion/Perfusion, MR-Functional imaging

Procedure Diagnostic procedure ; Special Focus Neoplasia ;

Show more Show less

Download as PDF Print Show related cases Notify admin

Clinical History

An 18 year-old male patient presented with a 3 months history of recurrent episodes of loss of consciousness. A thorough neurological examination as well as an EEG was performed; both were within normal limits.

Imaging Findings

The MRI revealed two lesions in the left frontotemporoinsular and the right temporal lobe region. Both lesions were hyperintense on FLAIR images with scant peritumoral oedema (Fig. 1). A second MRI, including fMRI and DTI protocols, was subsequently performed to identify the language-associated cortical areas.
Tractography demonstrated displacement of the fiber tracts surrounding the lesion. The arcuate fasciculus was posteriorly displaced on the left side but was unaffected on the right (Fig. 2). The part of the left corticospinal tract adjacent to the tumour was displaced and infiltrated (Fig. 3). Fractional anisotropy maps showed decreased fractional anisotropy within the lesion but no changes in the perilesional white matter (Fig. 4). No evidence of intercommunication of the two tumours was found with tractography.
Each tumour was excised in different procedures with the patient awake. The postsurgical MRI revealed total resection of both tumours with no language field deficits (Fig. 5-6).

Discussion

Low-grade gliomas are primary brain tumours that arise from glial cells. They are associated with high morbidity and mortality as well as the potential for anapaestic transformation [1]. Although uncommon, the incidence of multiple gliomas has been previously reported [2]. They can be grouped in two main categories: multicentric and multifocal. Multifocal gliomas disseminate from a primary site along nerve fiber bundles, cerebrospinal fluid channels and blood vessels. Multicentric gliomas on the other hand consist of separate entities, in different lobes or hemispheres, not caused by metastatic spread. The exact incidence of multiple gliomas is unknown, ranging between 0, 5% and 20% [3].
Clinical signs and symptoms are mainly attributed to the invasion of the surrounding parenchyma or the development of obstructive hydrocephalus [4]. They include seizures, cognitive and behavioural changes and focal neurologic deficits. However, patients can be completely asymptomatic.
On CT, low-grade gliomas appear as diffuse areas of low attenuation. On MRI they are often homogeneous with hypointesity on T1 weighted sequences and hyperintensity on T2 weighted and FLAIR sequences. Calcifications are seen in 20% of the cases and are particularly suggestive of oligodendrogliomas. Contrast enhancement is seen in up to 60% of the patients [4]. Even though CT and MRI can define the location of the tumour, they do not provide information about the functional viability of the adjacent ‘radiologically normal’ tissue. This need has been met by the application of fMRI and DTI techniques. fMRI is a non-invasive imaging modality used for mapping regions of the brain associated with motion, sensation, language, vision and other cognitive tasks [5]. DTI on the other hand provides precise information regarding the relationship between subcortical white matter structures and cerebral neoplasms. The data gathered from the DTI technique can be integrated into a standard neuronavigation system [6]. This can allow for the intraoperative visualization and localization of the major white matter tracts such as the pyramidal tract or the optic radiation, resulting in more controlled resections and reduced risk of postoperative neurological deficits [7].
In conclusion, multimodal MRI techniques can be used for the preoperative radiological evaluation of patients with multicentric gliomas, as fMRI and DTI can allow for the detection of the functional cortical areas as well as the subcortical connectivity. This enables us to provide tailored surgical treatment according to the individual radiological information, optimizing the benefit/risk ratio of the surgery and decreasing the rate of permanent deficit.

Differential Diagnosis List

Multicentric low grade gliomas

multifocal gliomas

metastases

lymphoma

infections

demyelinating diseases

oligodendrocytic gliomatosis cerebri

glioblastoma multiforme

neurofibromatosis

Final Diagnosis

Multicentric low grade gliomas

References

[1] Forst D, Nahed B, Loeffler J, Batchelor T. (2014) Low grade gliomas. The Oncologist 19:403-13 (PMID: 24664484)

[2] Batzdof U, Malamud N (1963) The problem of multi centric gliomas. J Neurosurg 20:122-36 (PMID: 14192080)

[3] Zamponi N, Rychliki F, Ducati A, Regnicolo L, Salvolini U, Ricciuti RA (2001) Muticentric glioma with unusual clinical presentation. Childs Nerv Syst 17:101-5 (PMID: 11219614)

[4] Pouratian N, Asthagiri A, Jagannathan J et al. (2007) The role of surgery in the management of the low grade gliomas. Nat Clin Pract Neurol 3(11):628-39 (PMID: 17982433)

[5] Schlosser R, Hunsche S, Gawehn J et al. (2002) Characterization of BOLD-f MRI signal during a verbal fluency paradigm in patients with intracerebral tumors affecting the frontal lobe. Magn Reson Imaging 20(1):7-16 (PMID: 11973025)

[6] Kamada K, Todo T, Masutani Y et al. (2005) Combined use of tractography integrated functional neuronavigation and direct fiber stimulation. J Neurosurg 102(4):664-72 (PMID: 15871509)

[7] Nimsky C, Ganslandt O, Fahlbusch R. (2007) Implementation of fiber tract navigation. Neurosurg 61(1):178-85 (PMID: 18813171)

Case information

URL:	https://www.eurorad.org/case/13254
DOI:	10.1594/EURORAD/CASE.13254
ISSN:	1563-4086

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Preoperative MRI FLAIR images

Axial FLAIR (Fluid Attenuated Inversion Recovery) images (A, B) reveal the high signal intensity of the two lesions located at the right temporal lobe and the left frontotemporal lobe regions respectively accompanied with ring-like oedema.

Figure 2

Preoperative Fractional Anisotropy color-mapping images

Axial FA colour-mapping images (A-D). The tumours, located at the right temporal and left frontotemporal regions, are visualized as a well-circumscribed bluish area, which is characteristic of low fractional anisotropy.

Figure 3

Preoperative DTI tractography images depicting the arcuate fasiculi

DTI tractography images (A-C) demonstrating the right and left arcuate fasiculli. The left one is not invaded but slightly displaced, while the right one is completely unaffected by the tumour.

Figure 4

Preoperative DTI tractography images of the corticospinal tracts

Coronal tractography DTI images (A,B) demonstrating the corticospinal tracts, showing thinning and displacement of the fibers on the left side.

Figure 5

Pre- and postoperative fMRI images

Presurgical fMRI image (A) showing functional language areas (Wernicke) on both temporal lobes in contact with the tumours. Postsurgically (B) the right functional area is shifted posterior to the porencephally.

Figure 6

Pre- and postoperative fMRI images.

Presurgical fMRI images(A) showing functional language areas on the left temporoparietal lobe posterior to the tumour. These areas remain almost untouched after the surgical excision of the tumour (B).