Quantification of aortic pulse wave velocity from a population based cohort: a fully automatic method

Table 2 Performance of the proposed automatic method

Measure	N	Manual	Automatic	R (CI for β)	B-A (95% CI)	Abs diff
Centerline length (mm)	198	131.6 ± 20.2	130.6 ± 19.5	0.98 (0.97, 0.98)	-1.0 (-9.3, 7.3)	3.3 ± 2.8
Inter-observer centerline length (mm)	45	132.0 ± 20.8^#	132.5 ± 20.1^&	0.97 (0.95, 0.99)	0.5 (-9.0, 10)	3.4 ± 3.4
Transit time foot-to-foot (ms)	186	16.7 ± 8.2	16.0 ± 5.7	0.98 (0.97, 0.98)	-0.1 (-2.4, 2.1)	0.9 ± 2.4
Transit time half-max (ms)	192	16.4 ± 5.0	16.5 ± 5.0	0.99 (0.99, 0.99)	0.1 (-1.1, 1.2)	0.4 ± 0.5
Transit time cross-correlation (ms)	192	14.4 ± 4.6	14.5 ± 4.7	0.97 (0.97, 0.98)	0.1 (-1.9, 2.2)	0.5 ± 0.9
Pulse wave velocity foot-to-foot (m/s)	186	9.5 ± 5.7	9.5 ± 5.2	0.89 (0.86, 0.92)	0.0 (-5.0, 5.0)	0.8 ± 0.9
Pulse wave velocity half-max (m/s)	192	8.8 ± 3.3	8.7 ± 3.4	0.99 (0.98, 0.99)	-0.1 (-1.2, 1.1)	0.4 ± 0.5
Pulse wave velocity cross-correlation (m/s)	192	10.4 ± 5.8	10.2 ± 5.5	0.98 (0.97, 0.98)	-0.2 (-2.6, 2.1)	0.7 ± 1.0

N is the number of measurments, Manual is the measurements obtained using the manual method (mean ±SD), Automatic is the measurement obtained using the proposed automatic method (mean ±SD), R is the Pearson correlation coefficient along with the linear regression β confidence interval (CI). B-A is the Bland-Altman bias along with the 95% CI. Abs diff is the average absolute difference between the manual and automatic measurements (mean ±SD). ^# Observer 1 and ^& Observer 2

ISSN: 1532-429X