1. A novel tool for three-dimensional roadmapping reduces radiation exposure and contrast agent dose in complex endovascular interventions 
Lars Stangenberg, MD, PhD, Fahad Shuja, MD, Bart Carelsen, PhD, Thijs Elenbaas, PhD, Mark C. Wyers, MD, Marc L. Schermerhorn, MD 
Journal of Vascular Surgery 
Volume 62, Issue 2, Pages (August 2015)
DOI: /j.jvs
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

2. Fig 1
A, A preoperative scan, either computed tomography angiography (CTA) or magnetic resonance angiography (MRA), is imported to the VesselNavigator workstation. B, After the vessels pertinent to the procedure had been selected, a three-dimensional (3D) model without disturbing other anatomic structures, such as bones, is displayed. In the present study, we routinely selected aorta, main and accessory renal arteries, and bilateral iliac systems including the internal iliac artery origins. Next, markers are placed on points of interest, such as branch vessel ostia or thrombus. Note the large aortic ring indicating the most proximal extent for the graft position. This ring is particularly useful to determine the exact projection angle to image the neck without parallax. C, Registration (fusion) of the 3D model to the patient on the operating room table is performed using the two-dimensional (2D)-3D method. The method employs two distinct plain images (anterior-posterior and 90-degree lateral projection) to fuse the live image and 3D roadmap by means of aligning bone structures. D and E, Alternatively and preferably, the registration is accomplished using the 3D-3D method. A C-arm cone-beam CT scan is obtained. Then, aortic calcifications are used as fiducials (small numbered markers) to align C-arm cone-beam CT (left) and preoperative CT (right) in all three planes. F, Finally, a fusion image consisting of live fluoroscopy and previously segmented vessels is displayed and used for live guidance. Note how the catheter follows the wall of the roadmap, suggesting a high degree of accuracy.
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

3. Fig 2
Results for radiation dose as air kerma (A), fluoroscopy time (B), contrast agent dose (C), and procedure length (D) after matching based on body mass index (BMI). N = 16 for each group; means ± standard deviations are shown; *P < .05.
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

4. Fig 3
Setup and intraoperative images. A, The check screen is shown after three-dimensional (3D)-3D registration has been performed. Note the well-aligned fiducials in all three planes while the bone landmarks (arrow) do not overlap. This is due to changes in positioning of the patient between computed tomography angiography (CTA) and fluoroscopy. The aorta as a central structure, however, is only minimally affected by this, allowing precise fusion using aortic calcifications. B, Predeployment VesselNavigator image is shown. Note the small marker rings indicating the renal artery orifices and the large ring indicating the safe proximal landing zone. C and D, Fusion images of VesselNavigator and digital subtraction angiography (DSA) before and after graft deployment are shown. The perirenal roadmap is aligned with the DSA image with high accuracy, whereas the more distal aorta and iliacs are not. This is due to straightening of flexible and tortuous vessel segments by stiff wires and grafts. It is an inherent design parameter of rigid registration technology. The mask is, however, accurate in fixed stable vessel segments, such as the visceral and perirenal aorta.
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions