Suitability of the Cordis Stabilizer™ marker guide wire for quantitative coronary angiography calibration: An in vitro and in vivo study

• Published in: Catheterization and cardiovascular interventions 2001-03, Vol.52 (3), p.334-341
• Main Authors: Koning, G., Hekking, E., Kemppainen, J.S., Richardson, G.A., Rothman, M.T., Reiber, J.H.C.
• Format: Article
• Language: English
• Subjects: Angiography, Digital Subtraction - instrumentation; Biological and medical sciences; Calibration; Cardiac Catheterization - instrumentation; Cardiovascular system; catheter; Coronary Angiography - instrumentation; Coronary Disease - diagnostic imaging; Coronary Disease - therapy; Equipment Design; foreshortening; guide wire; Humans; Image Enhancement; Image Processing, Computer-Assisted - instrumentation; Investigative techniques, diagnostic techniques (general aspects); Mathematical Computing; Medical sciences; out-of-plane magnification; Phantoms, Imaging; quantitative coronary angiography; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Reproducibility of Results
• ISSN: 1522-1946; 1522-726X
• DOI: 10.1002/ccd.1077

Catheters usually are used for calibration purposes in quantitative coronary angiography (QCA). The systematic and random errors in these calibration factors (CFs) are dependent on the size and quality of the catheters and limited by out‐of‐plane magnification (OPM). Theoretically, a guide wire with evenly spaced marker bands would solve many of these potential problems. For this reason, we tested the Cordis Stabilizer™ marker wire, featuring 10 radiopaque platinum marker bands 15 mm apart, in in vitro and in vivo studies. To assess the effect of foreshortening, wires were positioned in a tube phantom; a centimeter grid was used as the gold standard. Radiographic images were acquired at 5‐inch and 7‐inch image‐intensifier sizes, 5122 and 1,0242 matrix sizes and angulations from 0° to 70° in steps of 10°. It was concluded that the relative errors in CFs are less than 7% if the foreshortening angles remain less than 20°. In DICOM images of 15 patients, 65 measurements were taken after calibration on an 8F catheter and on a guide wire positioned in the coronary lesion. In all but two cases, the wire CFs were larger than the catheter CFs (relative difference, 24.7 ± 19.6%). The measurements were divided into four groups: (I) no apparent OPM or foreshortening (n = 7), (II) only OPM (n = 4), (III) only foreshortening (n = 10), and (IV) the combination of both (n = 44). In group I (no OPM or foreshortening) the QCA results were similar using the guide wire or catheter as the calibration device (relative CF difference, 2.9% only). In group III the diameters were overestimated using the guide wire (obstruction diameter difference, 0.22 ± 0.11 mm; reference diameter difference, 0.35 ± 0.06 mm). For only OPM (group II) and the combination of OPM and foreshortening (group IV), the lesion length was underestimated on average by 2.4 mm using the catheter instead of the guide wire. In conclusion, if accurate assessment of the lesion length is important, the marker wire should be used for calibration purposes. For vessel diameter measurements, the conventional catheter calibration approach is the method of choice. Cathet Cardiovasc Intervent 2001;52:334–341. © 2001 Wiley‐Liss, Inc.