The purpose was to evaluate CT findings of hemorrhage extending along the pulmonary artery (PA) due to ruptured aortic dissection (AD) and its prognostic factors. In 232 patients with Stanford type A AD, 21 patients (9.1%; 11 women; mean 70.3 years) were diagnosed. Twelve patients had double-barreled (classic) AD, and nine patients had intramural hematoma (IMH; closed false lumen) of the aorta. Based on CT findings, hemorrhage was classified into three categories as follows: category 1 (IMH of the PA or blood localized around the PA), category 2 (extending into the interlobular septa), and category 3 (extending into the alveoli). The factors influencing prognosis, including CT features and patient characteristics, were evaluated. Fourteen (66.7%) of the 21 patients underwent emergency surgery, and 8 (38.1%) patients died within 72 h of onset. Twelve cases (57.1%) were classified into category 1, 2 cases (9.5%) into category 2, and 7 cases (33.3%) into category 3. Double-barreled AD and category 3 hemorrhage were significant risk factors for death in univariate analyses. In multivariate analyses, the presence of category 3 hemorrhage was the only significant risk factor for death. CT findings indicative of a poor prognosis include double-barreled type AD and category 3 hemorrhage.