The “egg-and-banana” sign is a valid computed tomography (CT) marker of pulmonary hypertension (PH), according to the results of a retrospective study published in the American Journal of Radiology.
Chris L. Scelsi, DO, from the Department of Radiology, Medical College of Georgia, Augusta University in Augusta, Georgia, and colleagues reviewed all consecutive right heart catheterizations performed between January 2014 and July 2017, and then screened those to identify any CT studies that were performed within 140 days before or after right heart catheterization and included the aortic arch and the most caudal aspect of the main pulmonary artery (PA).
A total of 186 patients were evaluated, and of these, 127 had PH, whereas the 59 patients who did not have PH served as the control group. Two blinded radiologists evaluated each study for the egg-and-banana sign and also measured the diameters of the main PA and ascending aorta. Statistical analysis included contingency tables, receiver operating characteristic curves, and a t test.
The investigators found that the egg-and-banana sign was associated with a higher mean PA pressure, as well as a higher ratio of the diameter of the PA to the diameter of the ascending aorta (PA-to-Ao ratio), and a larger PA diameter (P <.006).
The egg-and-banana sign had a specificity of 85% and a positive predictive value of 85%. When used with a main PA diameter larger than 29 mm and a PA-to-Ao ratio greater than 1, the specificity of the egg-and-banana sign rose to 91% and 93%, respectively.
Taken on their own, PA diameter had a sensitivity of 80%, and PA-to-Ao ratio had a specificity of 81%.
The authors concluded that when the egg-and-banana sign is used in concert with the more classic CT markers of PH of main PA diameter and PA-to-Ao ratio, the specificity for PH is very high.
Scelsi CL, Bates WB, Melenevsky YV, Sharma GK, Thomason NB, Keshavamurthy JH. Egg-and-banana sign: a novel diagnostic CT marker for pulmonary hypertension [published online April 18, 2018]. Am J Radiol. doi:10.2214/AJR.17.19208