The British Journal of Radiology, Vol 68, Issue 813 1017-1020, Copyright © 1995 by British Institute of Radiology

ARTICLES

Technical note: inspiration or expiration? Reducing motion artefact in digital subtraction arch angiography of the extracranial carotid arteries

DJ Withers and RJ Ashleigh
Department of Radiology, University Hospital of South Manchester, Withington Hospital, UK.

100 consecutive patients underwent digital subtraction aortic arch angiography for suspected carotid bifurcation disease. Patients were prospectively randomized to suspend respiration in inspiration or expiration during image acquisition. Images were assessed qualitatively as "excellent", "adequate" or "poor". 92 studies were available for review. Adequate and poor groups were combined into a non-excellent group due to the small numbers that were scored poor. There were 27 (53%) excellent, 24 (47%) non-excellent in the expiration group and 12 (29%) excellent, 29 (71%) non-excellent in the inspiration group. Analysis of angiogram scores gave chi 2(1) = 4.3; p = 0.038, indicating that the higher angiogram scores of the expiration group were statistically significant. Pixel shifting was used in 61 cases (66.3%). The proportion was 34.4% lower in the expiration group (95% CI; 17-52%) with chi 2(1) = 10.5; p = 0.0012 indicating that the reduction in the use of pixel shifting for the expiration group was statistically significant. The superiority of arch angiograms obtained with the patient suspending respiration in expiration rather than inspiration has been demonstrated. This was achieved with significantly reduced use of pixel shifting, encouraging greater confidence in the validity of the angiographic findings. The technique is free of cost or time implications.