| Summary: | Background: Abdominal aortic calcification (AAC) is an independent determinant of cardiovascular events. Computed tomography (CT) is currently the gold standard for measuring aortic calcification but is limited by relatively high radiation exposure. Lateral dual-energy X-ray absorptiometry (lateral-DXA) has the potential to detect AAC at a fraction of the radiation dose.
Objectives: To evaluate the potential for lateral DXA scans to detect AAC in comparison to CT in healthy post menopausal women.
Methods: Thirty-four women from the TwinsUK registry aged 50–75 years underwent a non-contrast CT and lateral DXA scan of the abdominal aorta from vertebrae L1 to L4. Presence of calcium was scored using the Agatston method for CT, where a weighting factor is assigned to the calcified region based on the x-ray attenuation and multiplied by the area of the calcified region. Lateral DXA images were scored using a previously validated semi-quantitative 24 point score, where the anterior and posterior aortic walls were divided into 4 lumbar regions and graded 0–3 according to prevalence of AAC.
Results: Calcification (any detectable abdominal calcification) was present in 65% of women as determined by CT and 51% with lateral-DXA. Agreement between CT and lateral DXA scores was good (Spearman’s rank correlation coefficient r=0.70, P<0.0001). The sensitivity of lateral DXA scores for detecting AAC was 68% and the specificity 80%.
Conclusion: Lateral DXA imaging provides a useful alternative to CT in detecting AAC with minimal radiation.
|
|---|
