Validation of an arterial tortuosity measure with application to hypertension collection of clinical hypertensive patients

BMC Bioinformatics

Table 5 Helix Phantom tortuosity

Phantom	Peak Distance Factor Metric	Approximate coils	Peak DFM/2.80 ratio
Pitch 5(2π)	20.95	8	7.48
Pitch 10(2π)	10.76	4	3.84
Pitch 20(2π)	5.45	2	1.95
Pitch 40(2π)	2.80	1	1.00

The peak distance factor metric tortuosity scores are lower with increasing pitch of the three-dimensional helix phantoms.