Stereolithography compatible input images of the lumen (a) and lumen with the thrombus (b) sent to the stereolithography process to create epoxy resin skeletons representing the lumen (c) and lumen with the thrombus (d). The skeletons in (c) and (d) were used to create the master silicone molds of the AAA geometry; the holders on the resin skeletons were removed from the silicone molds. Note that the iliac bifurcations were artificially jointed together for attachment to a single connector of the phantom.
AAA phantom with the isomalt core painted with polyurethane (in dark for black and white display) used to create the lumen and thrombus (upstream of the bifurcation) before pouring the mimicking agar-oil gel of the abdomen within the polyethylene container.
MRA examination of the phantom. (a) T1 weighted spin echo sequence without contrast, (b) T1 weighted spin echo sequence with contrast, and (c) T2 weighted sequence without contrast. The differentiation between the lumen, the thrombus, and the agar-oil abdominal gel is well demonstrated on all acquisitions and signal intensities are similar to those observed clinically. (d) T1 weighted spin echo sequence, showing a plane with visible fiducial markers in the peripheral fatty layer (hyposignal intensity). (e) T1 weighted 3D FLASH gradient echo sequence with contrast injection. The lumen, thrombus, agar-oil abdominal gel, and peripheral fatty layer can still be differentiated. No clinical MRA examination of the patient used as a model to build this phantom was available for comparison.
(a) Axial CTA scan acquisition showing the thrombus with a slightly higher density than the surrounding agar-oil gel of the abdomen and a strong enhancement of the lumen by the contrast agent. (b) Coronal acquisition showing the differentiation between the lumen, the thrombus, and the surrounding tissue. Fiducial markers are well delineated in both panels. (c) Coronal acquisition of the patient used as a model to build this phantom.
Digital spot film acquired with the DSA unit showing the lumen of the AAA and fiducial markers in the background (arrow). No clinical DSA examination of the patient used as a model to build this phantom was available for comparison.
(a) Ultrasound B-mode image showing a longitudinal view of the lumen and thrombus of the AAA. A strong attenuation of the echo signal is seen at the bottom of the image. This is due to the thick layer of polyurethane that was used to prevent puncture of the vessel wall when deploying the stent-graft; this is a requirement that we did not have to consider in the previous art (see Refs. 29 and 30 ). (b) Longitudinal ultrasound acquisition of the patient AAA used as a model to build this phantom.
CTA image showing a stent graft deployed into the lumen of the AAA phantom and a visible thrombus. Fiducial markers are seen in the background of the image.
Shear stress τ as a function of applied shear strain ϒ for the agar-oil gel mimicking the abdominal aorta.
Shear stress τ as a function of applied shear strain ϒ for the agar-glycerol gel mimicking the thrombus.
Shear stress τ as a function of applied shear strain ϒ for the polyurethane mimicking the vessel wall.
SNR values of the different components of the AAA phantom (lumen, thrombus, mimicked abdomen, and fatty layer embedding glass ball markers).
CNR values of the different components of the AAA phantom.
Clinical values (HU) obtained from the CTA of the patient used as a model for our AAA phantom.
Article metrics loading...
Full text loading...