Erschienen in:
01.08.2003 | Clinical Investigations
Three-Dimensional Ultrasound-Based Navigation Combined with
Preoperative CT During Abdominal Interventions: A
Feasibility Study
verfasst von:
J.H. Kaspersen, E. Sjølie, J. Wesche, J. Åsland, J. Lundbom, A. Ødegård, F. Lindseth, T.A. Nagelhus Hernes
Erschienen in:
CardioVascular and Interventional Radiology
|
Ausgabe 4/2003
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Abstract
Purpose: Three-dimensional (3D)
intraoperative ultrasound may be easier to interpret when used in
combination with less noisy preoperative image data such as CT. The
purpose of this study was to evaluate the use of preoperative image
data in a 3D ultrasound-based navigation system specially designed for
minimally invasive abdominal surgery. A prototype system has been
tested in patients with aortic aneurysms undergoing clinical assessment
before and after abdominal aortic stent-graft implantation.
Methods: All patients were first imaged by spiral CT
followed by 3D ultrasound scanning. The CT volume was registered to the
patient using fiducial markers. This enabled us to compare
corresponding slices from 3D ultrasound and CT volumes. The accuracy of
the patient registration was evaluated both using the external fiducial
markers (artificial landmarks glued on the patient’s skin) and using
intraoperative 3D ultrasound as a measure of the true positioning of
anatomic landmarks inside the body.
Results: The mean
registration accuracy on the surface was found to be 7.1 mm, but
increased to 13.0 mm for specific landmarks inside the body. CT and
ultrasound gave supplementary information of surrounding structures and
position of the patient’s anatomy. Fine-tuning the initial patient
registration of the CT data with a multimodal CT to intraoperative 3D
ultrasound registration (e.g., mutual information), as well as ensuring
no movements between this registration and image guidance, may improve
the registration accuracy.
Conclusion: Preoperative CT
in combination with 3D ultrasound might be helpful for guiding minimal
invasive abdominal interventions.