title: Distal aortic intramural hematoma: clinical importance of focal contrast enhancement on CT images.
abstract: OBJECTIVE
  To investigate the prevalence, fate, and effect of focal contrast enhancement lesion within the hematoma on contrast material-enhanced computed tomographic (CT) images in patients with distal aortic intramural hematoma (IMH).
  
  
  METHODS
  This retrospective study was approved by the institutional review board; informed consent was waived. Clinical and CT data in 107 patients with distal IMH who received medical treatment were analyzed, including remodeling processes of IMH at follow-up CT. IMH progression was defined as development of aortic dissection (AD) and aneurysm or hematoma increase.
  
  
  RESULTS
  The frequency of focal contrast enhancement was 39.3%, and hematoma was thicker in patients with focal contrast enhancement than in those without (12.3 mm ± 3.6 [standard deviation] vs 10.1 mm ± 4.1, P = .006). Although development of AD occurred more frequently in patients with focal contrast enhancement (21% vs 3%, P = .006), hematoma resorption (57% vs 71%) was the most common pattern of remodeling in both groups without any significant difference (P = .148). The frequency of development of aortic aneurysm (17% vs 14%, P = .690) and increase of hematoma (0% vs 5%, P = .278) was not significantly different between groups. The 1-, 3-, 5-, and 7-year survival rates were 96.3% ± 1.8, 95.2% ± 2.1, 87.9% ± 3.4, and 80.7% ± 4.4, respectively. Patients with IMH progression showed lower survival rates than those without (P = .028). While no significant difference in the overall survival rates could be demonstrated in patients with and those without focal contrast enhancement (P = .442), our study had only 17% power to detect a difference of 10%. Initial maximal aortic diameter was the only factor associated with survival rates (hazard ratio = 1.129; 95% confidence interval: 1.063, 1.199). The optimal cutoff for prediction of mortality within 7 years was 41 mm.
  
  
  CONCLUSIONS
  Urgent intervention for patients with focal contrast enhancement is not necessary during the acute stage, and long-term close monitoring with imaging is a better option considering diverse remodeling processes of distal IMH.
authors.affiliation: Divisions of Cardiology and Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-dong Songpa-gu, Seoul 138-736, South Korea.
authors.forename: Gyung-Min
authors.initials: GM
authors.lastname: Park
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Ahn
authors.forename: Dae-Hee
authors.initials: DH
authors.lastname: Kim
authors.forename: Joon-Won
authors.initials: JW
authors.lastname: Kang
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Song
authors.forename: Duk-Hyun
authors.initials: DH
authors.lastname: Kang
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Lim
authors.forename: Jae-Kwan
authors.initials: JK
authors.lastname: Song
mesh_terms: D001018:Aortic Diseases / Q000000981:diagnostic imaging* / Q000401:mortality*; D003287:Contrast Media; D005260:Female; D006406:Hematoma / Q000000981:diagnostic imaging* / Q000401:mortality*; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D056910:Republic of Korea / Q000453:epidemiology; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide