“Egg-and-Banana Sign” on CT Scan for Diagnosis of Pulmonary Hypertension

Tassapol Sukolsakul; Suwimon Wonglaksanapimon; Kanyarat Totanarungroj

Authors

Tassapol Sukolsakul Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand https://orcid.org/0000-0002-9512-3446
Suwimon Wonglaksanapimon Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand https://orcid.org/0000-0001-7541-1988
Kanyarat Totanarungroj Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand https://orcid.org/0000-0003-4760-9270

Keywords:

egg-and-banana sign, pulmonary hypertension

Abstract

Objective The “egg-and-banana” sign refers to an increased main pulmonary diameter (MPAD) seen in the main pulmonary artery (PA) at the same level as the most caudal point of the aortic arch. This study aimed to determine whether identification of the egg-and-banana sign on CT scans can help in the diagnosis of pulmonary hypertension (PH).

Methods A retrospective study was conducted of 110 patients at Siriraj Hospital between January 2017 and November 2020. Clinical characteristics, CT scans, and echocardiograms were reviewed. The egg-and-banana sign, MPAD and ascending aorta were reviewed and their diagnostic performance as CT features of PH were analyzed.

Results The egg-and-banana sign showed 41.6% sensitivity, 84.9% specificity, 86.5% positive predictive value and 38.4% negative predictive value for the detection of PH. When it was used together with MPAD > 29 mm and PA:AAo ratio > 1, specificity increased to 87.9%, sensitivity of MPAD was high (97.4%; AUC value, 0.866) and specificity of the PA:AAo ratio showed a high value (81.8%; AUC value, 0.838) for PH individually. The egg-and-banana sign was found to be related to a higher mean PA pressure (mPAP), a higher PA:AAo ratio, and a larger MPAD. Moderate correlations between mPAP and MPAD and between mPAP and PA:AAo ratio were found.

Conclusions The egg-and-banana sign may be useful in the detection of PH. It has high specificity and high PPV for PH. The use of the egg-and-banana sign in conjunction with other well-known CT features, the MPAD and PA:AAo ratio, can boost the specificity and PPV for detection of PH.

References

Thai Guideline for Diagnosis and Treatment of Pulmonary Hypertension 2013. [cited 2020 Dec 4]. Available from: http://www.thaiheart.org/images/column_1385016166/PAH_guideline_2013.pdf

Simonneau G, Gatzoulis MA, Adatia I, Celermajer D, Denton C, Ghofrani A, et al. Updated clinical classification of pulmonary hypertension. J Am Coll Cardiol. 2013;62(25 Suppl):D34-41.

Ni J-R, Yan P-J, Liu SD, Hu Y, Yang KH, Song B, et al. Diagnostic accuracy of transthoracic echocardiography for pulmonary hypertension: a systematic review and meta-analysis. BMJ Open. 2019;9: e033084.

Ng CS, Wells AU, Padley SP. A CT sign of chronic pulmonary arterial hypertension: the ratio of main pulmonary artery to aortic diameter. J Thorac Imaging. 1999;14:270-8.

Mahammedi A, Oshmyansky A, Hassoun PM, Thiemann DR, Siegelman SS. Pulmonary artery measurements in pulmonary hypertension: the role of computed tomography. J Thorac Imaging. 2013;28:96-103.

Scelsi CL, Bates WB, Melenevsky YV, Sharma GK, Thomson NB, Keshavamurthy JH. Egg-and-banana sign: a novel diagnostic CT marker for pulmonary hypertension. AJR Am J Roentgenol. 2018; 210:1235-9.

Sánchez Nistal MA. Pulmonary hypertension: the contribution of MDCT to the diagnosis of its different types. Radiologia (Madr). 2010;52:500-12.

Devaraj A. Assessment of pulmonary artery pressure using computed tomography signs in various diseases. (thesis) London, UK: University of London, 2009.

Abbas AE, Fortuin FD, Schiller NB, Appleton CP, Moreno CA, Lester SJ. A simple method for noninvasive estimation of pulmonary vascular resistance. J Am Coll Cardiol. 2003;41:1021-7.

Abbas AE, Fortuin FD, Schiller NB, Appleton CP, Moreno CA, Lester SJ. Echocardiographic determination of mean pulmonary artery pressure. Am J Cardiol. 2003;92:1373-6.

Peña E, Dennie C, Veinot J, Muñiz SH. Pulmonary hypertension: how the radiologist can help. Radio Graphics. 2012;32:9-32.

Devaraj A, Hansell DM. Computed tomography signs of pulmonary hypertension: old and new observations. Clin Radiol. 2009;64:751-60.

McGoon M, Gutterman D, Steen V, Barst R, McCrory DC, Fortin TA, et al. Screening, early detection, and diagnosis of pulmonary arterial hypertension: ACCP evidence-based clinical practice guidelines. Chest. 2004;126:Suppl. 1 14S–34S.

Kuriyama K, Gamsu G, Stern RG, Cann CE, Herfkens RJ, Brundage BH. CT-determined pulmonary artery diameters in predicting pulmonary hypertension. Invest Radiol. 1984;19:16-22.

Chan AL, Juarez MM, Shelton DK, MacDonald T, Li CS, Lin TC, et al. Novel computed tomographic chest metrics to detect pulmonary hypertension. BMC Med Imaging. 2011;11:7.

Tan RT, Kuzo R, Goodman LR, Siegel R, Haasler GB, Presberg KW. Utility of CT scan evaluation of predicting pulmonary hypertension in patients with parenchymal lung disease. Medical College of Wisconsin Lung Transplant Group. Chest. 1998; 113:1250-6.