Background: Cardiovascular disease has been a major cause of death in many countries and aortic diseases contribute to the high overall cardiovascular mortality. Dissection is the most common emergency affecting the thoracic aorta and unless swiftly established with proper management can result in death.(2) CT Aortogram is a rapidly progressing diagnostic imaging modality with great potential since it is more cost-effective requiring less imaging time as compared to MR Aortogram and Conventional Aortogram. Hence, allowing more rapid diagnosis and decision making which in effect saves more lives.
Methods: The CT Aortograms of 37 patients were independently evaluated by 2 radiologists for the presence or absence of wall hyperattenuation, wall thickness, intraluminal size, intrinsic wall calcification, intraluminal lesion size and ulcer-like projection. These were taken note of and inter-observer variability was checked. Validity measures, such as sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy were determined. Multi-variate analysis was done to determine which among the different CTA criteria would be the best diagnostic predictor/s for aortic dissection and intramural hematoma. who were not aware of each other's reading and clinical diagnosis.
Results: Intimal flap was demonstrated in 5 out of 5 patients diagnosed with aortic dissection, however this was also seen in 4 (15%) patients with intramural hematoma. Among the intramural hematoma patients, hyperattenuation of the wall was the most frequent finding which was noted in 96% (26 of 27 IMH patients). The extent of the lesion in patients with intramural hematoma covers more than J;4 of the aortic circumference, while it covers more than half in those with aortic dissection. It was noted that in patients with aortic dissection the wall thickness was more than half of the aortic diameter and in those with intramural hematoma, the wall thickness was between Y2 and % of the aortic diameter.
Conslusion: Based on this study, CT angiogram is highly specific and sensitive in the diagnosis of thrombosed aortic dissection and intramural hematoma. Aside from this, CT Angiogram is also very specific and sensitive in differentiating the two entities. The most useful angiographic