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.



Case Type

Clinical Cases


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

18 years, male

Area of Interest Neuroradiology brain ; Imaging Technique MR, MR-Diffusion/Perfusion, MR-Functional imaging
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).
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
demyelinating diseases
oligodendrocytic gliomatosis cerebri
glioblastoma multiforme
Final Diagnosis
Multicentric low grade gliomas
Case information
DOI: 10.1594/EURORAD/CASE.13254
ISSN: 1563-4086