The diagnostic value of contrast enhancement on MRI in diffuse and anaplastic gliomas

Acta Neurochirurgica (2022) 164:2035–2040

We evaluated differentiations in gadolinium contrast enhancement (CE) between low-grade WHO °II and high-grade WHO °III gliomas in conventional MRI, which have been repeatedly questioned.

Methods Ninety-nine patients, who underwent first resection of WHO°II and °III gliomas, were retrospectively retrieved from a prospective database. The quantitative metric volume of Gd-CE in T1-weighted pre-operative MRI was measured using volumetric segmentation.

Results The OR to detect CE in anaplastic gliomas was seven times higher than that in diffuse gliomas (CI95% 2.817.2, p<0.0001). No CE was seen in 50% (8/16) of focal anaplastic and in 28% (10/36) of entirely anaplastic gliomas. CE was present in 21% (10/47) of diffuse gliomas. Anaplasia correlated with a larger CE volume (r=0.49, p<0.0001) and provided additional 4 cm 3 of CE volume compared to entirely diffuse tumors. The OR to have CE was 3.6 times for IDH1 wild-type tumors (CI95% 1.3–10.2, p=0.05) and 4.8 for tumors with ATRX expression (CI95% 1.3–17.2, p=0.05). In all sub-groups, at least a quarter of cases showed no CE at all and there were cases with present CE.

Conclusion CE is associated with higher odds of unfavorable prognostic features like anaplasia, wild-type IDH1 and retained ATRX. There was no CE in one-fourth of anaplastic gliomas and half of gliomas with focal anaplasia.

Advanced MRI may complement histological diagnosis of lower grade gliomas and help in predicting survival

Advanced MRI may complement histological diagnosis of lower grade gliomas and help in predicting survival

J Neurooncol (2016) 126:279–288

MRI grading of grade II and III gliomas may have an important impact on treatment decisions. Occasionally, both conventional MRI (cMRI) and histology fail to clearly establish the tumour grade. Three cMRI features (no necrosis; no relevant oedema; absent or faint contrast enhancement) previously validated in 196 patients with supratentorial gliomas directed our selection of 68 suspected low-grade gliomas (LGG) that were also investigated by advanced MRI (aMRI), including perfusion weighted imaging (PWI), diffusion weighted imaging (DWI) and spectroscopy. All the gliomas had histopathological diagnoses.

Sensitivity and specificity of cMRI preoperative diagnosis were 78.5 and 38.5 %, respectively, and 85.7 and 53.8 % when aMRI was included, respectively. ROC analysis showed that cut-off values of 1.29 for maximum rCBV, 1.69 for minimum rADC, 2.1 for rCho/Cr ratio could differentiate between LGG and HGG with a sensitivity of 61.5, 53.8, and 53.8 % and a specificity of 54.7, 43 and 64.3 %, respectively. A significantly longer OS was observed in patients with a maximum rCBV\1.46 and minimum rADC[1.69 (80 vs 55 months, p = 0.01; 80 vs 51 months, p = 0.002, respectively). This result was also confirmed when cases were stratified according to pathology (LGG vs HGG). The ability of aMRI to differentiate between LGG and HGG and to predict survival improved as the number of aMRI techniques considered increased.

In a selected population of suspected LGG, classification by cMRI underestimated the actual fraction of HGG. aMRI slightly increased the diagnostic accuracy compared to histopathology. However, DWI and PWI were prognostic markers independent of histological grade.

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