Comparison of the diagnostic information in relative cerebral blood volume, maximum concentration, and subtraction signal intensity maps based on magnetic resonance imaging of gliomas

RATIONALE AND OBJECTIVES. The authors investigate the validity of regional relative cerebral blood volume (rCBV) versus maximum concentration and subt raction signal intensity (SI) maps using simple reconstruction modes in pat ients with gliomas. METHODS. Twenty-five patients were studied using a 1.5 T magnetic resonance imaging scanner. To calculate the rCBV map, the magnetic resonance suscept ibility effect SI/time curves were first transformed into concentration/tim e curves; then a gamma-variate function was fitted and the area under the c urve was integrated, From the concentration/time data, the maximum concentr ation (MAX) maps were calculated pixel per pixel as the maximum peak amplit ude of the concentration/time curve. Subtraction (SUB) maps are a result of simple image subtraction of pixelwise baseline SI minus the highest peak o f susceptibility change pixel per pixel. Region of interest means SI measur ement of the different maps was compared using statistical t test correlati on. RESULTS. Normal gray to white matter contrast did not show a significant di fference among the rCBV, MAX, and SUB maps. Based on statistical evaluation , the low-grade lesions did not differ significantly in the rCBV, MAX, and SUB maps, The group with high-grade lesions (12 patients) showed no signifi cant difference in standardized rCBV, MAX, and SUB maps. CONCLUSION. Compared to rCBV maps, the simple MAX and SUB maps demonstrated good correlation in both high-grade and low-grade gliomas, This simpler ap proach could establish first-pass reconstructions in clinical settings beca use it reduces the need for time-consuming postprocessing.