Table 3.

Comparison of image-derived volumes and metrics of small-vessel arterial and venous volume fractions and arterial/venous ratios for CTEPH and control groups

	CTEPH	Control	P valuea
Arterial fractions
Small vessels, BV5ART/TBVART
Whole lung	0.46 (0.32–0.52)	0.60 (0.50–0.64)	0.0005
Right lung	0.49 (0.37–0.55)	0.61 (0.52–0.66)	0.0009
Left lung	0.40 (0.29–0.46)	0.59 (0.50–0.67)	0.001
Large vessels, BV>10ART/TBVART
Whole lung	0.35 (0.30–0.41)	0.23 (0.21–0.31)	0.0005
Right lung	0.32 (0.30–0.36)	0.23 (0.19–0.29)	0.0002
Left lung	0.35 (0.32–0.41)	0.24 (0.21–0.31)	0.0009
Venous fractions
Small vessels, BV5VEIN/TBVVEIN
Whole lung	0.48 (0.39–0.52)	0.53 (0.46–0.62)	0.07
Right lung	0.51 (0.40–0.54)	0.54 (0.49–0.59)	0.086
Left lung	0.45 (0.32–0.49)	0.51 (0.44–0.57)	0.027
Large vessels, BV>10VEIN/TBVVEIN
Whole lung	0.28 (0.26–0.32)	0.29 (0.27–0.34)	0.6
Right lung	0.28 (0.26–0.32)	0.27 (0.26–0.32)	0.93
Left lung	0.28 (0.26–0.32)	0.30 (0.25–0.34)	0.66
Arterial/venous ratios
Small vessels, BV5ART/BV5VEIN
Whole lung	1.31 (1.15–1.39)	1.22 (1.07–1.36)	0.32
Right lung	1.24 (1.10–1.52)	1.22 (1.09–1.45)	0.76
Left lung	1.33 (1.11–1.44)	1.24 (1.03–1.31)	0.06
Large vessels, BV>10ART/BV>10VEIN
Whole lung	1.75 (1.26–2.3)	0.82 (0.76–1.20)	<0.001
Right lung	1.52 (1.2–2.15)	0.85 (0.68–1.15)	<0.0001
Left lung	1.97 (1.31–2.65)	0.90 (0.76–1.24)	0.0001
Overall, TBVART/TBVVEIN
Whole lung	1.41 (1.16–1.59)	1.09 (0.97–1.19)	0.002
Right lung	1.34 (1.11–1.51)	1.09 (1.01–1.22)	0.044
Left lung	1.45 (1.24–1.8)	1.05 (1.0–1.22)	0.0005

^NoteData reported as median (interquartile range). BV5: volume of vessels detected with cross sectional area ≤ 5 mm² (small vessels); BV>10: volume of vessels detected with cross sectional area > 10 mm²; CTEPH: chronic thromboembolic pulmonary hypertension; TBV: total volume of vessels detected.

^aP value based on a Wilcoxon exact test with a 2-sided P value.