title: CT-navigated real-time ultrasonography: evaluation of registration accuracy for clinical application.
abstract: Ultrasound examination is a valuable diagnostic tool in almost all medical disciplines. However, the results are highly dependent on the experience and performance of the individual examiner and the technical conditions of the examination. Since computed tomography (CT) is not affected by these factors, the combination of real-time ultrasound images and previously compiled CT scans with identical cross-sections displayed simultaneously during transcutaneous ultrasonography could be advantageous. To evaluate the practical applicability and reliability of CT-supported transcutaneous ultrasonography, we examined 10 patients with a Real-Time Virtual Sonography Unit using a previously compiled CT scan as a reference. The results were evaluated by 10 sonographers with different levels of experience. By using the 3-point registration method almost identical ultrasound and CT cross-sections were displayed throughout the examination. However, there was a constant lateral and height deviation of the CT image detected. The crucial point is the correct and reliable referencing of the real-time ultrasound. In conclusion, the CT-navigated ultrasound seems not yet complete for clinical applications. Although helpful for training purposes, it is not accurate enough yet to play a role in routine clinical diagnostic work up.
authors.affiliation: Department of Surgery, Technical University Munich, Klinikum Rechts der Isar, Munich, Germany. kranzfelder@chir.med.tu-muenchen.de
authors.forename: Michael
authors.initials: M
authors.lastname: Kranzfelder
authors.forename: Martin
authors.initials: M
authors.lastname: Dobritz
authors.forename: Dirk
authors.initials: D
authors.lastname: Wilhelm
authors.forename: Emmanouel
authors.initials: E
authors.lastname: Doundoulakis
authors.forename: Armin
authors.initials: A
authors.lastname: Schneider
authors.forename: Hubertus
authors.initials: H
authors.lastname: Feussner
mesh_terms: D003199:Computer Systems; D004067:Digestive System Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*