PURPOSE: To determine empirically the effect of scan parameters and postprocessing techniques on depiction accuracy of renal artery stenosis with spiral computed tomographic angiography. MATERIALS AND METHODS: Critical (85%) and noncritical (45%) stenoses in the coronal plane were modeled in vitro and scanned with 12 combinations of collimation (1, 2, or 3 mm), table increment (pitch = 1-2),2 and reconstruction interval (0.5 or 1.0 mm). Five test images were generated for each spiral scanning technique: multiplanar reformation (MPR), maximum-intensity projections (MIPs: coronal MIP [MIPcor], coronal MIP targeted to phantom vessel and surrounding fat [target MIPcor]), transaxial imaging, and transaxial MIP. RESULTS: With 3-mm collimation, critical stenosis was overestimated to the point of occlusion on MIPcor images and underestimated on MPR and target MIPcor images. A 0.5-mm reconstruction interval was marginally beneficial for 1- and 2-mm collimation, but noise was prohibitive with 1-mm collimation. CONCLUSION: Critical renal artery stenosis is best depicted with 2-mm collimation, 2-4-mm table increment, and 1-mm reconstruction interval.
PURPOSE: To determine empirically the effect of scan parameters and postprocessing techniques on depiction accuracy of renal artery stenosis with spiral computed tomographic angiography. MATERIALS AND METHODS: Critical (85%) and noncritical (45%) stenoses in the coronal plane were modeled in vitro and scanned with 12 combinations of collimation (1, 2, or 3 mm), table increment (pitch = 1-2),2 and reconstruction interval (0.5 or 1.0 mm). Five test images were generated for each spiral scanning technique: multiplanar reformation (MPR), maximum-intensity projections (MIPs: coronal MIP [MIPcor], coronal MIP targeted to phantom vessel and surrounding fat [target MIPcor]), transaxial imaging, and transaxial MIP. RESULTS: With 3-mm collimation, critical stenosis was overestimated to the point of occlusion on MIPcor images and underestimated on MPR and target MIPcor images. A 0.5-mm reconstruction interval was marginally beneficial for 1- and 2-mm collimation, but noise was prohibitive with 1-mm collimation. CONCLUSION:Critical renal artery stenosis is best depicted with 2-mm collimation, 2-4-mm table increment, and 1-mm reconstruction interval.
Authors: L Van Hoe; D Vandermeulen; S Gryspeerdt; L Mertens; A L Baert; P Suetens; G Marchal; L Stockx Journal: Eur Radiol Date: 1996 Impact factor: 5.315
Authors: B B Ertl-Wagner; R Bruening; J Blume; R-T Hoffmann; S Mueller-Schunk; B Snyder; M F Reiser Journal: AJNR Am J Neuroradiol Date: 2006-01 Impact factor: 3.825
Authors: M T Farrés; J Lammer; W Schima; B Wagner; R Wildling; F Winkelbauer; S Thurnher Journal: Cardiovasc Intervent Radiol Date: 1996 Mar-Apr Impact factor: 2.740