Table 3.

Key characteristics of previous studies on imaging venous thromboembolism in pregnancy (in order of publication date)

Study	CTPA					VQ scan
	n	Diagnosis			Alternative diagnosesa (%)	n	Diagnosis
		PE (%)	No PE (%)	Indeterminate (%)			PE (%)	No PE (%)	Indeterminate (%)
Ridge et al (2009)14	28	0	64	36	3.6	25	8	88	4
Shahir et al (2010)29,b	106	3.8	91	5.7	2.5	98	0	98	2
Revel et al (2011)30,c	43	16	65	19	12	91	11	70	19
This studyd	23	17	48	35	13	89	12	87	1

CTPA, CT pulmonary angiography; PE, pulmonary embolism; VQ, ventilation/perfusion.

^aSignificant findings not seen on chest radiograph.

^bCT diagnostic quality: 76% good, 18% acceptable, 5.7% non-diagnostic.

^cCT enhancement: 50% optimal, 26% suboptimal, 24% poor; 4.7% respiratory artefacts.

^d35% suboptimal enhancement of subsegmental vessels.