Fig 4. Boxplot of arterial attenuation in 50 patients scanned with both SP-CTA and MP-CTA protocols. Error bars indicate the range of values of arterial attenuation. Boxes contain all values within the 25th–75th percentiles (interquartile range), and thick black lines represent the median. The arterial enhancement peak phase of the MP-CTA is shown for comparison. A, Boxplot of attenuation of the exact same region of the largest artery in the scanning range, representing enhancement in the large vessel. The 3 circles are outliers measured in 1 patient. B, Boxplot of attenuation of the exact same region of the M2 segment in the scanning range, representing enhancement in the small vessel.