The Interobserver Agreement between Residents and Experienced Radiologists for Detecting Pulmonary Embolism and DVT with Using CT Pulmonary Angiography and Indirect CT Venography

Abstract

ObjectiveWe wanted to prospectively evaluate the interobserver agreement between radiology residents and expert radiologists for interpreting CT images for making the diagnosis of pulmonary embolism (PE).Materials and MethodsWe assessed 112 consecutive patients, from April 2007 to August 2007, who were referred for combined CT pulmonary angiography and indirect CT venography for clinically suspected acute PE. CT scanning was performed with a 64×0.5 collimation multi-detector CT scanner. The CT studies were initially interpreted by the radiology residents alone and then the CT images were subsequently interpreted by a consensus of the resident plus an experienced general radiologist and an experienced chest radiologist.ResultsTwo of the 112 CTs were unable to be interpreted (1.7%). Pulmonary artery clots were seen on 36 of the thoracic CT angiographies (32%). The interobserver agreement between the radiology residents and the consensus interpretation was good (a kappa index of 0.73). All of the disagreements (15 cases) were instances of overcall by the resident on the initial interpretation. Deep venous thrombosis was detected in 72% (26 of 36) of the patients who had PE seen on thoracic CT. The initial and consensus interpretations of the CT venography images disagreed for two cases (kappa statistic: 0.96).ConclusionIt does not seem adequate to base the final long-term treatment of PE on only the resident's reading, as false positives occurred in 13% of such cases. Timely interpretation of the CT pulmonary angiography and CT venography images should be performed by experienced radiologists for the patients with suspected PE.

PENet—a scalable deep-learning model for automated diagnosis of pulmonary embolism using volumetric CT imaging

“…Studies has shown that there can be up to a 13% discrepancy rate between overnight radiologists and daytime faculty. [5][6][7] Increasing pressure is placed on hospital systems to provide 24-7 access to advanced imaging and to ensure that the results of urgent findings, such as PE, are rapidly and accurately communicated to the referring clinician. 8,9 However, providing rapid and accurate diagnostic imaging is increasingly difficult to sustain for many medical systems and radiology providers as utilization has expanded; for example, CTPA usage alone in the emergency setting has increased 27-fold over the past 2 decades.…”

Overdiagnosis of Pulmonary Embolism by Pulmonary CT Angiography

“…The published overall rate of positive diagnosis of PE on pulmonary CTA varies from study to study (e.g., 15.4% [14], 16.4% [13], and 17.8% [6]) but usually ranges between 14% [20] and 22% [7]. Differing levels of adherence to referral guidelines, which has been shown to significantly affect positivity rates, may explain some of this variation; for example, 30% of all pulmonary CTA examinations were positive for PE in the multicenter Christopher Study [2], which used strict adherence to a basic pretest risk stratification tool.…”

“…Despite this, however, reported interobserver agreement varies widely, especially in the diagnosis of subsegmental PE [12]. Wide variations in concordance between general and subspecialist radiologists have been reported (89-100%) [13,14], as well as between residents, fellows, and attending radiologists (87-93%) [15][16][17]. Although pulmonary CTA examinations are frequently interpreted by general radiologists in most centers, limited data exist on the interobserver agreement between general and subspecialist chest radiologists.…”

CT Venography for Deep Vein Thrombosis Using a Low Tube Voltage (100 kVp) Setting Could Increase Venous Enhancement and Reduce the Amount of Administered Iodine

“…However, determining the period of peak enhancement is difficult in the venous system. Therefore, CTV is usually scanned in the equilibrium phase after injection of CM (2, 4, 7-13). A high concentration of iodine CM or a larger volume of CM must be used to increase venous attenuation in CTV (14).…”