The Use of Computed Tomography of Pulmonary Angiogram in a District Hospital

Table 2

Stratification of the CTPA requests according to the simplified Wells score and D-dimer (𝑛=88).

Simplified Wells score§		D-dimer; (Cut-off = 500 mcg/L FEU)		No. of PE
Low (≤4)	77	Not done	18*	1*
		Negative	5^†	0^†
		Positive	54	8
High (>4)	11	Not done	6	1
		Negative	0	0
		Positive	5	2

§Consists of previous pulmonary embolism or deep vein thrombosis, 1.5 point; heart rate >100 beats/minute, 1.5 point; recent surgery or immobilisation (within the last 30 days), 1.5 point; clinical signs of deep vein thrombosis, 3 points; alternative diagnosis less likely than pulmonary embolism, 3 points; haemoptysis, 1 point; and active cancer (treated within the last 6 mo), 1 point [2].
*Demonstrates that 18 scans were performed on patients with low Wells score who did not have D-dimer testing. One of these 18 scans showed PE.
^†Demonstrates that 5 scans were performed on patients with low Wells score with negative D-dimer. None of these 5 scans revealed PE.