Accuracy of computed tomography angiography in the detection of pulmonary embolism in patients with high body weight

• We assessed accuracy of CT pulmonary angiography in patients with high body weight.
• CT angiography results were compared with a clinical composite reference standard.
• Diagnostic accuracy did not differ between patients weighing 75–99 kg or 100–150 kg.
• CT pulmonary angiography performed similar in non-obese and obese patients < 150 kg.

BackgroundThe accuracy of CT pulmonary angiography (CTPA) in detecting or excluding pulmonary embolism has not yet been assessed in patients with high body weight (BW).MethodsThis retrospective study involved CTPAs of 114 patients weighing 75–99 kg and those of 123 consecutive patients weighing 100–150 kg. Three independent blinded radiologists analyzed all examinations in randomized order. Readers' data on pulmonary emboli were compared with a composite reference standard, comprising clinical probability, reference CTPA result, additional imaging when performed and 90-day follow-up. Results in both BW groups and in two body mass index (BMI) groups (BMI < 30 kg/m2 and BMI ≥ 30 kg/m2, i.e., non-obese and obese patients) were compared.ResultsThe prevalence of pulmonary embolism was not significantly different in the BW groups (P = 1.0). The reference CTPA result was positive in 23 of 114 patients in the 75–99 kg group and in 25 of 123 patients in the ≥ 100 kg group, respectively (odds ratio, 0.991; 95% confidence interval, 0.501 to 1.957; P = 1.0). No pulmonary embolism-related death or venous thromboembolism occurred during follow-up. The mean accuracy of three readers was 91.5% in the 75–99 kg group and 89.9% in the ≥ 100 kg group (odds ratio, 1.207; 95% confidence interval, 0.451 to 3.255; P = 0.495), and 89.9% in non-obese patients and 91.2% in obese patients (odds ratio, 0.853; 95% confidence interval, 0.317 to 2.319; P = 0.816).ConclusionThe diagnostic accuracy of CTPA in patients weighing 75–99 kg or 100–150 kg proved not to be significantly different.