Experimenting with ASL-based arterialized cerebral blood volume as a novel imaging biomarker in grading glial neoplasms.

BACKGROUND: Perfusion imaging is one of the methods used to grade glial neoplasms, and in this study we evaluated the role of ASL perfusion in grading brain glioma. PURPOSE: The aim is to evaluate the role of arterialized cerebral blood volume (aCBV) of multi-delay ASL perfusion for grading glial neoplasm. MATERIALS AND METHODS: This study is a prospective observational study of 56 patients with glial neoplasms of the brain who underwent surgery, and only cases with positive diagnosis of glioma are included to evaluate the novel diagnostic parameter. RESULTS: In the study, ASL-derived normalized aCBV (naCBV) and T2*DSC-derived normalized CBV (nCBV) are showing very high correlation (Pearson's correlation coefficient value of 0.94) in grading glial neoplasms. naCBV and nCBF are also showing very high correlation (Pearson's correlation coefficient value of 0.876). The study also provides cutoff values for differentiating LGG from HGG for normalized aCBV(naCBV) of ASL, normalized CBV (nCBV), and normalized nCBF derived from T2* DCS as 1.12, 1.254, and 1.31, respectively. ASL-derived aCBV also shows better diagnostic accuracy than ASL-derived CBF. CONCLUSION: This study is one of its kind to the best of our knowledge where multi-delay ASL perfusion-derived aCBV is used as a novel imaging biomarker for grading glial neoplasms, and it has shown high statistical correlation with T2* DSC-derived perfusion parameters.

Unusual imaging appearance of a rare cortical ependymoma mimicking angiocentric glioma.

Cortical ependymomas are uncommon lesions. We report a cortical ependymoma displaying an unusual imaging pattern. The lesion demonstrated a T1 hyperintense rim and limited perilesional edema but lacked contrast enhancement. T1 hyperintense rim and stalk-like ventricular extension of FLAIR hyperintensity have previously been considered pathognomonic of angiocentric glioma. Hence, we conclude that the radiologists should be aware of this uncommon imaging pattern of cortical ependymoma. The condition warrants prompt surgical management in view of the increased potential for higher grade transformation, unlike grade I roman numeral may be given angiocentric gliomas.