Analysis of the mismatched manifestation between rCBF and rCBV maps in cerebral astrocytomas

Abstract

Objective To explore the mismatched manifestation between regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV) of astrocytomas. Methods Both conventional and perfusion CT were performed on 29 patients with pathologically confirmed astrocytomas (15 cases in Grades I–II, 14 cases in Grades III–IV). Time-density curves were plotted, cerebral blood flow and volume maps were generated, and the values between rCBF and rCBV in the same region of interest (ROI) were compared. Results Twelve low-grade astrocytomas showed low or medium values of both rCBF (46.95±22.92 ml ⋅ 100 g −1 ⋅ mm −1) and rCBV (5.74±3.61 ml ⋅ 100 g −1); 12 high-grade astrocytomas showed high values of both rCBF (95.44±42.58 ml ⋅ 100 g −1 ⋅ min −1) and rCBV (9.24±5.32 ml ⋅ 100g −1). These cases exhibited agreement between the values of rCBF and rCBV. However, the remaining five astrocytomas were mismatched, showing reduced rCBF value and increased rCBV value in the same ROI. The discrepancy may mislead to an inaccuracy of perfusion CT in grading gliomas. Conclusions The mismatched manifestation between rCBF and rCBV occasionally exists in some areas of astrocytomas. Hence, attention should be paid to assessments in preoperative grading of astrocytomas and in monitoring therapeutic effects.