An analysis of initial and follow-up CT findings in intramural hematoma, aortic double-lumen dissection, and mixed type lesions

Abstract

Background Although the clinical presentation of intramural hematoma (IMH) and aortic double-lumen dissection (AD) is similar, the imaging results and subsequent clinical course of the two lesions differ. Purpose To compare the clinical and radiological findings of IMH, AD, and mixed type lesions. Material and Methods Forty-two patients with IMH, 38 with AD, and 10 with mixed type lesions were imaged with post-contrast-enhanced CT. The most proximal ulcer-like lesions and entry tears and the distal ends of the IMH and AD were evaluated. The interval change of the intramural hematoma, ulcer-like lesion, and false lumen was observed. The pathological findings of the aorta were evaluated in 15 patients. Results The most proximal ulcer-like lesion and entry tear were located in the arch to the descending aorta in 27 (64.2%) of the 42 patients with IMH and in 24 (63.1%) of the 38 patients with AD. The distal extension was located at the iliac arteries in six (14.3%) patients with IMH and in 31 (81.6%) patients with AD ( P < 0.001). The intramural hematomas regressed in 29 (93.5%) of 31 patients, and the ulcer-like lesion progressed in 14 (70%) of 20 patients with IMH. The clinical features of the mixed type lesions resembled those of AD, rather than IMH. The intramural hematoma or dissection was observed within the outer media in all lesion types on histopathology. Conclusion There is a distinct difference between IMH and AD in distal extension; however, the locations of the lesions are pathologically the same in the media of the aorta.