Diagnostic Performance of Perfusion MRI in Differentiating Low-Grade and High-Grade Gliomas: Advanced MRI in Glioma, A Siriraj Project
Thanyaporn Direksunthorn MD*, Orasa Chawalparit MD*, Tumtip Sangruchi MD**, Theerapol Witthiwej MD***, Siri-on Tritrakarn MD*, Siriwan Piyapittayanan MD*, Panida Charnchaowanish BSc*, Prapaporn Pornpunyawut BSc*, Sith Sathornsumetee MD****
Affiliation : * Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand ** Department of Pathology, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand *** Division of Neurosurgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand **** Division of Neurology, Department of Internal Medicine, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand
Background : To determine the usefulness of the perfusion MRI technique at Siriraj Hospital for differentiating between
high- and low-grade gliomas by using pathological results as the gold standard.
Material and Method: The authors prospectively investigated 64 consecutive patients who were suspected as cerebral
glioma from prior conventional imaging. Cerebral perfusion study was achieved during the first pass of a bolus of gadolinium-
based contrast agent. All post-processing MRI images were interpreted by two board-certified neuroradiologists (more than
10-year-experience), one radiology resident and one well-trained technician, who separately performed and blinded from
the pathological results.
Results : Forty-four patients diagnosed as glioma were included in this study. There were 26 cases of high-grade and
18 cases of low-grade gliomas. The cerebral blood volume and flow and its ratios had a strong association with the grade
of glioma. The areas under the ROC curve for CBV, CBV ratio (rCBV), CBF, and CBF ratio (rCBF) are 0.778, 0.769, 0.769,
and 0.772, respectively. On the basis of equal misclassification rates, a cutoff value of 6.15 for CBV (sensitivity, 81.5%;
specificity, 64.7%), a cutoff value of 2.38 for the rCBV (sensitivity, 88.9%; specificity, 64.7%), a cutoff value of 0.66 for
CBF (sensitivity 81.5%; specificity 70.6%), and a cutoff value of 2.6 for the rCBF (sensitivity, 85.2%; specificity, 70.6%)
best discriminated the high and low-grade gliomas.
Conclusion : Preoperative radiologic grading of gliomas based on conventional MR imaging is sometimes unreliable. The
cerebral perfusion measurements can significantly improve the sensitivity and predictive values of radiologic glioma grading.
The rCBV measurement is the best parameter for tumor grading due to the highest sensitivity.
Keywords : Perfusion MRI, Cerebral blood volume, Cerebral blood flow, Glioma
