Diagnostic accuracy of diffusion weighted MRI in differentiating benign and malignant meningiomas

Abstract

Objective: To determine the diagnostic accuracy of DWI in differentiating benign and malignant meningiomas keeping histopathology as gold standard.
 Methods: This was a descriptive analytical study conducted at Radiology Department, DUHS/Dr. Ruth K. M. Pfau Civil Hospital Karachi, from August 2016 to March 2018. It included152 patients clinically suspected of meningioma on conventional neuroimaging. Imaging features of DWI were compared with histopathology findings. The diagnostic accuracy of DWI was calculated in terms of sensitivity, specificity, accuracy, PPV and NPV using histopathology as gold standard.
 Results: There were 59 male and 93 female patients with mean age of 55.38±9.8 years. Mean duration of sign and symptoms was 5.67±2.57 months. Out of 152 patients, 117(77%) and 35(23%) were differentiated into benign and malignant meningiomas respectively by DWI while 135(88.82%) and17(11.18%) patients were diagnosed respectively on histopathology. The sensitivity, specificity, PPV, NPV and accuracy of DWI of 84.4%, 82.3%, 97.4%, 40%, and 84.2% respectively keeping histopathology as gold standard.
 Conclusion: DWI features along with calculation of ADC values is a reliable non-invasive technique for differentiating benign and malignant meningiomas. However the low negative predictive value necessitates the use of histopathology.
 doi: https://doi.org/10.12669/pjms.35.3.1011
 How to cite this:Sohu DM, Sohail S, Shaikh R. Diagnostic accuracy of diffusion weighted mri in differentiating benign and malignant meningiomas. Pak J Med Sci. 2019;35(3):---------. doi: https://doi.org/10.12669/pjms.35.3.1011
 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

The diagnostic value of apparent diffusion coefficient to differentiate benign and malignant meningiomas

“…In this study, the prevalence of malignant meningioma was higher than that of benign meningioma and this result was in line with a previous study conducted by Surov et al, (8) which showed that benign meningioma has a higher incidence than malignant meningioma. Similar to the previous study of Sohu et al, (1) there were more women among the subjects of the present study.…”

“…This study also showed a significant difference between ADC value in benign meningioma and malignant meningioma with the cutoff point at 0.886 x 10 -3 mm 2 /s, which is close to the ADC cutoff point of 0.85×10 "3 mm 2 /s in the studies of Sohu et al (1) and Surov et al (8) The ADC measured using diffusion-weighted imaging sequence has been studied previously in predicting the histological nature of brain tumors. (14,15) The ADC, which is calculated automatically by software, shows the magnitude of the diffusion of the water molecules.…”

“…Meningiomas are the most common intracranial non-axial primary tumors, ranging from 14 to 20% of all intracranial tumors and are common in middle-aged patients, with a male: female ratio of 1:2. (1) The incidence of meningiomas is 6:100,000 population, of which 2%-3% are asymptomatic, and 8% comprise multiple meningiomas. Most meningiomas are benign, slow-growing, and in some cases can be cured by surgery.…”

Differentiating between non-functioning pituitary macroadenomas and sellar meningiomas using ADC

“…However, the aforementioned methods sometimes may not lead to a confirmed etiological diagnosis because of the uncertainty of the origin of a lesion ( 13 ). Diffusion-weighted imaging (DWI) can noninvasively provide information concerning high signal-intensity regions as areas of increased cellularity and tissue microstructures by measuring water diffusion within a tissue ( 14 , 15 , 16 ), which is closely associated with membrane integrity and cell density ( 15 , 17 ). The diffusion of water molecules is determined by a high cellularity, a small extracellular space, and a high nuclear-to-cytoplasmic ratio ( 18 ).…”

“…Accordingly, the ADC values in brain tumors inversely associated with cellularity and the ratio of nuclear area to cytoplasm ( 18 ). Previous studies have reported that the ADC value or ratio plays an important role in the differentiation of brain tumors, including benign and atypical/malignant meningiomas and solitary fibrous tumors/hemangiopericytomas and meningiomas ( 16 , 19 , 20 , 21 ). However, few studies have assessed the role of ADC in the differentiation of non-functioning pituitary macroadenomas (NFPMAs) from sellar meningiomas.…”