Diagnostic accuracy of magnetic resonance imaging in detection of intra-axial gliomas

Abstract

Objective: To evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) in detection of intra-axial gliomas in suspected cases keeping histopathology as gold standard.

Methods: This cross-sectional study was conducted at Dow Institute of Radiology, DUHS from October 2017 - April 2018. Patients of either gender aged 30-70 years presenting with headache were included. Patients already diagnosed and referred for follow up were excluded. MRI was performed on 1.5T scanner by a trained MRI technician. T1, T2, FLAIR, diffusion weighted and T1 post contrast images were acquired and reviewed by two radiologists having more than five years post fellowship experience. Sensitivity, specificity, PPV, NPV and diagnostic accuracy of MRI for intraaxial gliomas was calculated taking histopathology findings as gold standard.

Results: Mean age of the patient`s was 51.71 ±10.85 years. Positive intraaxial gliomas on MRI were observed in 123 (79.90%) patients while on histopathology, positive intraaxial gliomas were observed in 131 (85.10%) patients. Diagnostic accuracy of MRI in detection of intra-axial gliomas taking histopathology findings as gold standard showed sensitivity, specificity, positive predicted value (PPV), negative predicted value (NPV) and overall diagnostic accuracy as 89.31%, 73.91%, 95.12%, 54.84% and 87.01%.

Conclusions: MRI has high sensitivity, moderate specificity and high diagnostic accuracy in detection of intraaxial gliomas.

Keywords: Diagnostic accuracy; Glioma; Magnetic resonance imaging; Sensitivity; Specificity.

Fig.1

T1 and T1 post contrast of Diffuse Astrocytoma. Abnormal signal intensity area noted in left frontal lobe appearing as hypointense on T1WI and shows no significant enhancement on contrast study

Fig.2

DWI and ADC of Diffuse Astrocytoma. The tumor in left frontal lobe show no diffusion restriction.

Fig.3

MRI of glioblastoma. A large mass in the right parietotemporal lobe causing significant mass effect with adjacent vasogenic oedema. It appears heterogeneously low on T1, high on T2 and irregular peripheral nodular enhancement. It has a central non-enhancing necrotic component.