Abstract 13698: Diagnostic Value of Non-Enhanced Multidetector Computed Tomography for Ruling Out Acute Aortic Dissection in Patients Presenting With Chest Pain or Back Pain
Background: Acute aortic dissection (AAD) is a life-threatening disorder which should be included in the differential diagnosis of patients presenting with acute chest pain or back pain to emergency department (ED). Multidetector computed tomography (MDCT) is an established modality for diagnosing AAD, however, there are few studies which focus on the diagnostic value of non-enhanced MDCT scanning. Therefore, we evaluated the usefulness of non-enhanced MDCT for ruling out AAD in these patients.
Methods: Of 810 patients who presented with acute chest pain or back pain to ED between January 2008 and February 2011, we retrospectively studied 93 patients with clinical suspicion of AAD who underwent both non-enhanced and enhanced 64-slice MDCT. The diagnosis of AAD was confirmed in 45 patients and refuted in 48. Two independent observers, blinded to the clinical information and the result of enhanced MDCT, assessed only non-enhanced MDCT data set of all patients. The diagnostic accuracy of non-enhanced MDCT parameters to detect AAD were calculated by using two-way contingency table analysis.
Results: Among the non-enhanced MDCT parameters, definite intimal flap which was defined as the presence of high density membrane-like structure in aorta clearly on serial axial images had a sensitivity of 93%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 94%. The addition of equivocal intimal flap which was defined as the presence of high density membrane-like structure in aorta ambiguously on at least one axial image increased the sensitivity to 98% and NPV to 98%, respectively. The interobserver and intraobserver agreements in interpretation of these parameters were high (kappa values of 0.81 and 0.85, respectively).
Conclusions: Non-enhanced 64-slice MDCT has high diagnostic ability for the detection of intimal flap in AAD patients. The absence of intimal flap in non-enhanced MDCT has excellent NPV for the detection of AAD, suggesting that non-enhanced MDCT is a highly effective modality for ruling out AAD in patients presenting with chest pain or back pain to ED. Contrast-enhanced MDCT scanning might be required for patients with suspected AAD by non-enhanced MDCT scanning to determine the classification of AAD.
- © 2011 by American Heart Association, Inc.