. 2018 Sep 26;31(5):298–310. doi: 10.1089/jamp.2017.1403

Table 3.

The Coefficient of Variation and Average of the Penetration Index Between Two-Dimensional Penetration Index and Three-Dimensional Penetration Index Between Anatomically Shaped Region Of Interest and Rectangular Box for Region Of Interest

Variable	PI_2D	PI_3D	p^a
COV (aROI)	0.059 ± 0.023	0.159 ± 0.056	<0.001
Mean (aROI)	0.611 ± 0.124	0.025 ± 0.013
COV (bROI)	0.064 ± 0.028	0.174 ± 0.068	<0.001
Mean (bROI)	0.615 ± 0.124	0.019 ± 0.010

^{^a}

Test t PI_2D < PI_3D/mean ± SD.

aROI, anatomically shaped region of interest; PI_2D, two-dimensional penetration index; PI_3D, three-dimensional penetration index.