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Susan Weeks

Publications and source records attributed to Susan Weeks.

3 recordsLinked to original sources
PubMed2005

Comparison of simultaneous and sequential two-view registration for 3D/2D registration of vascular images.

Accurate 3D/2D vessel registration is complicated by issues of image quality, occlusion, and other problems. This study performs a quantitative comparison of 3D/2D vessel registration in which vessels segmented from preoperative CT or MR are registered with biplane x-ray angiograms by either a) simultaneous two-view registration with advance calculation of the relative pose of the two views, or b) sequential registration with each view. We conclude on the basis of phantom studies that, even in the absence of image errors, simultaneous two-view registration is more accurate than sequential registration. In more complex settings, including clinical conditions, the relative accuracy of simultaneous two-view registration is even greater.

Algorithms↗
PubMed2003

Assessment of aorto-iliac disease with magnetic resonance angiography using arterial phase 3-D gradient-echo and interstitial phase 2-D fat-suppressed spoiled gradient-echo sequences.

PURPOSE: To evaluate magnetic resonance angiography (MRA) of the pelvis for the examination of the aorto-iliac system using arterial phase 3-D gradient echo and interstitial phase 2-D fat-suppressed spoiled gradient-echo (SGE), with comparison to surgery and angiography. MATERIALS AND METHODS: Ninety MR angiograms performed on 79 consecutive patients were analyzed, retrospectively, for the presence of narrowing, aneurysm, and dissection. Comparisons were made with angiography and surgery in 50 examinations, and a weighted kappa statistic test was applied to assess agreement. MR examinations were performed at 1.5T 3-D fast imaging in steady state precession (FISP) acquired immediately, and fat-suppressed SGE in the interstitial phase following gadolinium administration. RESULTS: MRA had overall sensitivities of 100% at aortic segments, 100% at common iliac, 93.8% at external, and 95.7% at internal iliac, and specificities of 100% at aortic segments, 89.7% at common iliac, 95.2% at external iliac, and 88.7% at internal iliac in detection of vascular disease. The agreement of MRA with the angiography and surgery yielded a weighted kappa statistic of 0.97 at the aortic, 0.94 at the common, 0.85 at the external, and 0.82 at the internal iliac segments. CONCLUSION: This study demonstrates an excellent performance of MRA in the evaluation of aorto-iliac arterial system and almost perfect agreement with angiography and surgery at all vascular levels.

Adult↗