‘Egg-and-banana sign’ proves a novel CT marker for pulmonary hypertension
A novel CT marker known as the “egg-and-banana sign” is aiding in the diagnosis of pulmonary hypertension (PH), an infamously hard-to-detect condition that affects hundreds of thousands of U.S. patients each year.
The illness, which can be triggered by genetics, gender, methamphetamine use and a host of other factors, is a known killer in the United States, Chris L. Scelsi, DO, and colleagues wrote in the American Journal of Roentgenology—but nobody really knows how widespread the disease actually is.
“With the development of new treatment options and advancements in management during the past decade, early diagnosis of PH is becoming critical,” Scelsi et al. wrote. “Because of the wide ranges of causes of PH, and because the only definitive method of diagnosis is right heart catheterization, the true prevalence is unknown.”
Right heart catheterization is the gold standard for measuring mean pulmonary artery pressure (MPAP), which is the diagnostic reference for PH and indicates presence of the condition if a patient’s MPAP is 25 mm Hg or higher.
“Noninvasive tests such as CT, echocardiography and cardiac MRI are playing larger roles in early diagnosis,” the authors said. “Newer CT markers, such as the egg-and-banana sign, have recently been introduced and can assist with diagnosis.”
Scelsi and co-authors wrote they were unsure of who coined the term “egg-and-banana," but the moniker refers to the appearance of the main pulmonary artery and the aortic arch, respectively. The marker isn’t routinely reporting during imaging, but minimal data has suggested a connection between the sign and MPAP.
The researchers retrospectively evaluated 186 patients for their trial, all of whom received right heart catheterizations and underwent CT studies that included the aortic arch within 140 days of catheterization. The majority of the pool—127 patients—had been previously diagnosed with PH, while the remaining 59 participants reported a clean bill of health. Two blinded radiologists reviewed scans for signs of the egg-and-banana phenomenon.
The authors found the egg-and-banana sign was strongly associated with higher mean pulmonary artery pressure, a higher ratio of the diameter of the pulmonary artery to the diameter of the ascending aorta and a larger pulmonary artery diameter. Combining study results, the egg-and-banana marker recorded both a specificity and a positive predictive value of 85 percent.
“Our analysis highlights the utility of the egg-and-banana sign as a new CT marker that is specific for PH,” Scelsi and colleagues wrote. “Identification of the egg-and-banana sign should prompt further diagnostic evaluation and can aid in early diagnosis of pulmonary hypertension.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.