title: Advanced inside-out tracking approach for real-time combination of MRI and US images in the radio-frequency shielded room using combination markers.
abstract: For the real-time fusion of different modalities, a variety of tracking methods are available including the optical, electromagnetic (EM) and image-based tracking. But as a drawback optical tracking suffers from line of sight issues and EM tracking requires the manual referencing for the fusion procedure and is not usable in Magnetic Resonance Imaging (MRI) environment. To avoid these issues, we propose a real-time setup containing a camera capable of inside-Out tracking using combined circular markers attached to Ultrasound (US) probe and a suitable platform for automatic overlay of MRI and US image using markers. This new approach could help clinicians carry out successful surgical procedures by requiring least system interaction and solving line of sight issues. As a proof-of-concept, we show our first result by mimicking common liver tumor intervention using framed marker fusion technique in a candle gel phantom. We evaluated the tracking error distances using the combination of special markers with Inside-Out approach and conventional optical tracking. The results achieved show comparable performance to the standard Outside-In tracking and manual reference approach, while easing the interventional procedure in terms of hardware and line of sight requirements.
authors.forename: Yeshaswini
authors.initials: Y
authors.lastname: Nagaraj
authors.forename: Christian
authors.initials: C
authors.lastname: Benedicks
authors.forename: Philipp
authors.initials: P
authors.lastname: Matthies
authors.forename: Michael
authors.initials: M
authors.lastname: Friebe
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003287:Contrast Media / Q000737:chemistry; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D019047:Phantoms, Imaging; D011835:Radiation Protection; D011846:Radio Waves; D015203:Reproducibility of Results; D012867:Skin / Q000473:pathology; D014463:Ultrasonography; D014867:Water / Q000737:chemistry
chemical_list: D003287:Contrast Media; D014867:Water