Comparison of colour Doppler ultrasound and digital subtraction angiography in the diagnosis of lower limb arterial disease.

A fifteen-month retrospective review (December 1993 to February 1995 inclusive) was performed comparing findings at Colour Doppler Ultrasound (CDU) and Digital Subtraction Angiography (DSA) in patients with symptomatic peripheral arterial disease or post-operative by-pass grafts. The records of 63 patients (43 males and 20 females) who had undergone both CDU and DSA within three months of each other were analysed. The age range of case studied was 33-84 years (mean 64 yrs.) Disease in each arterial or graft segment was classified into five grades, 0 (normal) to 4 (complete occlusion). A total of 72 limbs were examined. Fifty-four patients had unilateral symptoms while both limbs are affected in 9 cases. In all 241 arterial and graft segments were studied. There was overall agreement between findings of CDU and DSA in 193/241 (80/1%) and non-agreement in 48/241 (19.9%). Of the 48 examinations that showed discrepancy, the findings in 26/48 (54.2%) were one grade apart while in the remaining 22/48 (45.8%) there was a difference of two or more grades. Agreement between CDU and DSA in the individual arterial segments studied was as follows: common femoral 42/48 (87.5%); profunda femoris 19/25 (76.0%); superficial femoral 27/39 (81.0%); anterior tibial 17/81 (94.4%) and peroneal 15/17 (88/2%). In the grafts, there was an agreement of 20/27 (74/1%) between CDU and DSA. These results show a good correlation between the two imaging modalities with complete agreement and agreement within one grade in 80.1% and 90.9% of cases, respectively, confirming that CDU can be employed as a useful screening technique for assessment of symptomatic patients, allowing selection of patients for angioplasty alone or angiography for arterial mapping or those who require by-pass graft surgery.