Abstract 2774: Contrast Ultrasound Perfusion Imaging of the Lower Limb is Superior to Ankle-Brachial Index in the Diagnosis of Peripheral Arterial Disease
Aims The purpose of this study was to test whether contrast ultrasound perfusion imaging (CUPI) of the lower extremities might be superior to the ankle-brachial index (ABI) in assessing the severity of peripheral arterial disease (PAD).
Methods and Results Ultrasound contrast agent (SonoVue™) was injected into a peripheral vein of 55 PAD-patients and its appearance in the calf muscle was detected by low energy harmonic ultrasound. Analysis of the wash-in curves revealed a mean time to peak intensity (TTP) of 32.9s in Fontaine stage I (n=8), 41.1s in stage IIa (n=6), 39.7s in stage IIb (n=33), 39.2s in stage III and 74.7s in stage IV (n=3). Fifty-nine control subjects showed a significantly lower TTP of 20.8s (+/-6.4s) versus 40.8s (+/-15.4s) in all examined PAD patients (p<0.001). Collateralisation of the peripheral arteries was measured and scored by angiography in 47 PAD patients (not in stage I). There was a significant positive linear correlation (r=0.52, p<0.001) between TTP and the extent of collateralisation (moderate lesion and no collaterals - severe lesion and more than 2 collaterals - severe lesion and 0 to 2 collaterals - severe lesion and no collaterals) but not between ABI and collateralisation (r=-0.23, p=0.143). Furthermore, there was a significant positive linear correlation (r=0.33, p=0.017) between TTP and the location of the lesion (iliacal - femoral -popliteal or crural - all of them) but not between ABI and location (r=-0.16, p=0.252).
Conclusion The TTP correlates with the location of atherosclerotic lesions of the lower limbs and the degree of collateralisation whereas the ABI does not.