Role of Diffusion and Perfusion Magnetic Resonance Imaging in Predicting the Histopathological Grade of Gliomas - A Prospective Study

Role of Magnetic Resonance Imaging (MRI) in grading gliomas comparable with pathology: A cross-sectional study from Syria

Objective

Gliomas are one of the most common brain tumors in adults with a poor prognosis in most patients. Magnetic Resonance Imaging (MRI) plays a critical role in the diagnosis, management, and follow-up of gliomas. The aim of this study is to assess the sensitivity and specificity of MRI in the preoperative grading of supratentorial gliomas in comparison to histopathology.

Methods

A cross-sectional study included 39 patients, aged between 40 and 75 years with histologically diagnosed supratentorial gliomas who underwent conventional MR imaging, which included T1, T2, and FLAIR sequences from November 2018–December 2019 in the Department of Neurosurgery, Tishreen University Hospital, Lattakia. The histopathological typing and grading of the tumor were done by using 2016 WHO classification. The sensitivity, specificity, predictive value, and accuracy of MRI in determining tumor grade were calculated. The comparison was done between MRI findings and WHO histopathological grading.

Results

The overall sensitivity and specificity of MRI findings in the assessment of high-grade gliomas were 100% and 91% respectively. The positive predictive value (PPV) was 66.6%, and the negative predictive value (NPV) was 100%. The overall accuracy was 94.9%. The agreement between histopathological and MRI findings was 72%.

Conclusions

MRI plays an essential role in the initial diagnosis and grading of supratentorial gliomas with high sensitivity and specificity. It is considered a non-invasive method and is useful in cases where the biopsy procedure is a contraindication or rejected by the patient.

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Magnetic Resonance Imaging (MRI) plays a critical role in the diagnosis, management, and follow-up of gliomas.

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We report a study of 39 patients with histologically diagnosed supratentorial gliomas who underwent conventional MR imaging.

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MRI plays an essential role in the diagnosis and grading of supratentorial gliomas with high sensitivity and specificity.

Grading Gliomas Capability: Comparison between Visual Assessment and Apparent Diffusion Coefficient (ADC) Value Measurement on Diffusion-Weighted Imaging (DWI)

Background:

To compare diagnostic accuracy between DWI visual scale assessment and ADC value measurement of solid portion of the tumor in grading gliomas.

Methods:

This retrospective study included 38 patients who had pathologically proven gliomas between January 2013 and August 2018 with 18 low grade and 20 high grade tumors. All patients underwent MRI and biopsy. Two readers reviewed DWI visual scale independently. Disagreement was resolved by consensus. One reviewer measured ADC value of entire solid part of the tumor in single axial slice with greatest dimension of tumor which was chosen by consensus. Two data sets of visual scale and ADC value were analyzed and comparison of diagnostic accuracy in glioma grading was done by using area under the curve (AUC) of receiver operating characteristic curve (ROC).

Results:

Visual scale and ADC value could be used to distinguish between low and high grade gliomas with a statistically significant difference. (P-value 0.002 and <0.001). Almost all high grade gliomas had visual scale 5. The sensitivity, specificity, PPV NPV and accuracy were 50%, 100%, 100% , 64.3%,73.68% respectively. The cutoff level for the ADC value was determined to be 1119.48 x10^-6 mm²/s in differentiation between low and high grade gliomas with the sensitivity, specificity, PPV, NPV, accuracy of 90%, 88.89% , 90%, 88.9% and 89.47% respectively. There was no statistically significant difference(P-value = 0.163).

Conclusion:

Both Visual scale and ADC value were capable of differentiating between low and high grade gliomas. Although visual scale may not replace ADC measurement, larger scale prospective study is needed for validate this initial result.