Periaortic hematoma at diaphragmatic crura at helical CT: sign of blunt aortic injury in patients with mediastinal hematoma.
OBJECTIVE
To evaluate periaortic hematoma (PH) near the level of the diaphragm at abdominal computed tomography (CT) as an indirect sign of acute traumatic aortic injury after blunt trauma in patients with mediastinal hematoma.


METHODS
From 1998 to 2001, 97 patients with CT evidence of mediastinal hematoma after blunt thoracic trauma were retrospectively identified at two level 1 trauma centers. The presence or absence of PH near the level of the diaphragmatic crura was retrospectively established by a blinded reviewer at each institution. Aortic injury status was determined by reviewing angiographic, surgical, and clinical records. Sensitivity, specificity, positive and negative productive values, and positive and negative likelihood ratios were calculated.


RESULTS
Among the 97 patients with mediastinal hematoma, 14 had both PH near the level of the diaphragm and aortic injury; six had aortic injuries without PH, five had PH near the level of the diaphragm without aortic injury, and 72 had no evidence of PH near the diaphragm and no aortic injury. Sensitivity for PH near the level of the diaphragm as a sign of aortic injury was 70%; specificity, 94%; positive predictive value, 74%; and negative predictive value, 92%. The positive likelihood ratio for the presence of aortic injury was 10.8, and the negative likelihood ratio was 0.3.


CONCLUSIONS
PH near the level of the diaphragmatic crura is an insensitive but relatively specific sign for aortic injury after blunt trauma. The presence of this sign at abdominal CT should prompt imaging of the thoracic aorta to evaluate potential thoracic aortic injury.
Department of Radiology, Stanford University Medical Center, Stanford, Calif, USA.
Humberto
H
Wong
Michael B
MB
Gotway
A Daniel
AD
Sasson
R Brooke
RB
Jeffrey
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000293:injuries; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging* / Q000293:injuries*; D002648:Child; D002675:Child, Preschool; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D006406:Hematoma / Q000000981:diagnostic imaging* / Q000209:etiology; D006549:Hernia, Diaphragmatic, Traumatic / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D007223:Infant; D008297:Male; D008477:Mediastinal Diseases / Q000000981:diagnostic imaging / Q000209:etiology; D008875:Middle Aged; D011237:Predictive Value of Tests; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed; D014949:Wounds, Nonpenetrating / Q000150:complications / Q000000981:diagnostic imaging