Table 2.

The effect of normal chest X-rays on CTPA nondiagnosis (ND).

Pregnant/postpartum patients	Frequency of CXR completion prior to CT	Number of normal CXR	Number of ND CTPAs in patients with normal CXR
	55/83	38/55	16/38
	66.27%	69.10%	42.10%
		# abnormal CXR	# ND CTPAs in patients with abnormal CXR
		17/55	8/17.0
		30.90%	47.10%
Non pregnant/postpartum patients	Frequency of CXR completion prior to CT	Number of normal CXR	Number of ND CTPAs in patients with normal CXR
	66/89	41/66	10/41
	74.1%	62.1%	24.39%
		# abnormal CXR	# ND CTPAs in patients with abnormal CXR
		25/66	11/25
		37.80%	44.0%