The reproducibility of manual RV/LV ratio measurement on CT pulmonary angiography.

Objectives: Right ventricular (RV) dysfunction carries elevated risk in acute pulmonary embolism (PE). An increased ratio between the size of the right and left ventricles (RV/LV ratio) is a biomarker of RV dysfunction. This study evaluated the reproducibility of RV/LV ratio measurement on CT pulmonary angiography (CTPA). Methods: 20 inpatient CTPA scans performed to assess for acute PE were retrospectively identified from a tertiary UK centre. Each scan was evaluated by 14 radiologists who provided a qualitative overall opinion on the presence of RV dysfunction and measured the RV/LV ratio. Using a threshold of 1.0, the RV/LV ratio measurements were classified as positive (≥1.0) or negative (<1.0) for RV dysfunction. Interobserver agreement was quantified using the Fleiss κ and intraclass correlation coefficient (ICC). Results: Qualitative opinion of RV dysfunction showed weak agreement (κ = 0.42, 95% CI 0.37-0.46). The mean RV/LV ratio measurement for all cases was 1.28 ± 0.68 with significant variation between reporters (p < 0.001). Although agreement for RV/LV measurement was good (ICC = 0.83, 95% CI 0.73-0.91), categorisation of RV dysfunction according to RV/LV ratio measurements showed weak agreement (κ = 0.46, 95% CI 0.41-0.50). Conclusion: Both qualitative opinion and quantitative manual RV/LV ratio measurement show poor agreement for identifying RV dysfunction on CTPA. Advances in knowledge: Caution should be exerted if using manual RV/LV ratio measurements to inform clinical risk stratification and management decisions.

Identifying emergency pathology on abdominopelvic CT for non-radiologists.

Abdominal and pelvic computed tomography (CT) scans can be complex to interpret but sometimes significant abnormalities are relatively easy to recognize. In emergencies it is beneficial if physicians and surgeons can identify significant pathology that may immediately change patient management. Early image interpretation will allow clinicians to alert radiologists to provide prompt urgent reports, facilitate early referral to other specialities or expedite emergency surgery. This article provides non-radiologists with a systematic approach to identifying emergency pathology on abdominal and pelvic CT scans. It reviews the relevant cross-sectional anatomy and discusses the CT appearances of bowel perforation, bowel obstruction, bowel ischaemia (gangrene), bleeding, appendicitis and hydronephrosis using illustrative examples from the authors' clinical practice. Underlying causes for these conditions and the importance of interpreting the radiological appearances in conjunction with the patient's clinical condition and history are discussed. The authors hope that by using the POGBAH acronym and a systematic approach readers will be able to identify emergency pathology on abdominal and pelvic CT which may improve patient care.