Accuracy of intravascular ultrasound for diameter measurement of phantom arteries

Background. Uniplanar quantitative angiography (QA) is the standard method for measuring vessel diameter during surgical and endovascular procedures. Intravascular ultrasound (IVUS), a relatively new technology, is another me ans of obtaining this measurement. This study was designed to validate the accuracy of these two modalities by comparing each to direct caliper measur ement, the gold standard, using phantom femoral artery segments (PAS). Materials and methods. PAS diameter was measured with a 12.5-MHz mechanical ly rotating IVUS catheter (Boston Scientific Corp.) and QA (OEC Corp.) was compared to the direct caliper measurement (Mitutoyo Corp.) at 60 different locations within PAS. At each location minimal lumen diameter and perpendi cular lumen diameter were measured and their mean was calculated. The intra class correlation coefficients (ICCC) between direct caliper measurement an d IVUS and uniplanar and biplanar angiography were calculated. Fisher's Z t ransformation was used to compare the correlation coefficients. Results. The ICCC for IVUS was 0.89. The ICCCs for uniplanar and biplanar a ngiography were 0.73 and 0.82, respectively. IVUS correlated more closely w ith direct caliper measurement than uniplanar and biplanar angiography (P = 0.00008, 0.02) Biplanar angiography correlated more closely with direct ca liper measurement than uniplanar angiography (P = 0.04). Conclusions. IVUS more accurately measures lumen diameter than uniplanar or biplanar angiography. Diameter measurement with biplanar angiography is mo re accurate than uniplanar angiography. (C) 2001 Academic Press.