['Aortic growth rate in acute type B aortic dissection (ABAD) is a significant predictor for aortic complications and death. To improve the overall outcome, radiologic predictors might stratify patients who benefit from successful medical management vs those who require intervention. This study investigated whether the number of identifiable entry tears in ABAD patients is associated with aortic growth.', 'ABAD patients with uncomplicated clinical conditions and therefore treated with medical therapy were evaluated. Those with a computed tomography angiography (CTA) obtained at clinical presentation and a subsequent CTA obtained at least 90 days after medical treatment were included (2005 to 2010). The CTAs were investigated for the number of entry tears between the true and false lumen. Diameters of the dissected aortas were measured at five levels on the baseline and on the last available follow-up CTA, and annual aortic growth rates were calculated. The number of entry tears in these patients and the location in the aorta were compared with the aortic growth rate.', 'Included were 60 patients who presented with 243 dissected segments. Mean growth rates during follow-up (median, 23.2; range, 3 to 132 months) were significantly higher in patients with 1 entry tear (5.6 ± 8.9 mm) than in those with 2 (2.1 ± 1.7 mm; p = 0.001) and 3 entry tears (mean 2.2 ± 4.1; p = 0.010). The distance of the primary entry tear from the left subclavian artery did not have an effect on the aortic growth rate (median, 38; interquartile range, 24 to 137 mm; p = 0.434).'] Is number of entry tears associated with aortic growth in type B dissections?