Fig 7. Impact of vendor differences in T1 measurement.

Here, we have plotted the reported T₁ of low grade glioma and glioblastomas [8] and an estimate for each vendor system of the diagnostic range for low grade glioma and glioblastomas based on the bias and dispersion of that system. The challenge is to define a diagnostic criterion based on T₁ to distinguish low grade glioma from glioblastoma that would be suitable across vendor systems. If T₁ relaxation time is measured using IR (A), the overestimate of values by vendor E is small compared to the range of physiological values, and as a result, T₁ measured by IR could be a reliable measure across vendor systems. However, if the VFA method is used (B), the underestimate of T₁ on vendor D could inaccurately diagnose a glioblastoma as a low-grade glioma, an incorrect determination with serious impacts to patient management.