PHANTOM FOR CALIBRATION OF PREOPERATIVE IMAGING MODALITIES IN ENDOLUMINAL STENT-GRAFT REPAIR OF AORTIC-ANEURYSMS

PURPOSE: Successful deployment of an endoluminal prosthesis for repair of an abdominal aortic aneurysm (AAA) is critically dependent on accu rate preoperative assessment of aneurysm morphology with use of such m odalities as contrast aortography (CA), spiral computed tomography (CT ), magnetic resonance (MR) imaging, and intravascular ultrasonography (IVUS), The authors describe a new phantom that could be used both to calibrate these four imaging modalities and to determine which imaging technique(s) is (are) best for preoperative ABA sizing.MATERIALS AND METHODS: A life-sized AAA model was constructed of silicone elastomers with luminal access ports for introduction of contrast media and cath eters, Contrast material-filled rings were positioned circumferentiall y along the length of the model as reference points for dimension meas urements, The modalities were compared to each other relative to the a ctual dimensions of the model, as determined at its construction. RESU LTS: In this pilot study, all modalities were relatively similar in th eir ability to measure the dimensions of the AAA model, Length measure ments accounted for most of the interinstitutional and interobserver v ariability, MR imaging had the least variability, CONCLUSIONS: The aut hors developed a new phantom that can be imaged successfully with CA, CT, MR imaging, and IVUS in repetitive, reproducible fashion, Structur al refinements and future larger scale, statistically significant eval uations of such models should establish this as a useful adjunct in mu lticenter endoluminal stent-graft trials to allow calibration of imagi ng modalities and to determine which modality or modalities is (are) b est for preoperative AAA sizing.