Do radiologists detect chronic thromboembolic disease on computed tomography?

Background Chronic thromboembolic pulmonary hypertension (CTEPH), a complication of acute pulmonary embolism, is a potentially curable form of pulmonary hypertension (PH). CTEPH is under-diagnosed for a number of reasons leading to delayed referral or missed diagnosis; however, the frequency of misdiagnosis of CTEPH findings on computed tomography (CT) is currently unknown. Purpose To evaluate the extent of misdiagnosis of CTEPH on CT. Material and Methods We studied the original CT reports from 35 patients with confirmed CTEPH diagnosis referred to a specialist center for pulmonary endarterectomy during 2011–2016. The patients’ CT reports were assessed according to a standardized form and compared to a consensus reading by two expert radiologists. Results The expert reading identified all CTEPH cases. However, in the original reports, the terminology “CTEPH” was only used in two patients. Another seven descriptive reports picked up the combination of PH and vascular signs of CTEPH without making a definitive diagnosis. Taking these nine cases as positive for CTEPH, the overall sensitivity on a diagnostic level was 26%. Pulmonary arterial abnormalities were described in isolation in 63% with no mention of PH or CTEPH. Signs of PH and mosaic attenuation were documented in 53% and 6% of the original reports, respectively, where it could be seen on the CT examination. Conclusion The study shows that radiologists frequently miss CTEPH findings, leading to a falsely low sensitivity for CT. There was also a notable discrepancy in how the findings were presented in radiology reports.