title: 3D Ultrasonic Needle Tracking with a 1.5D Transducer Array for Guidance of Fetal Interventions.
abstract: Ultrasound image guidance is widely used in minimally invasive procedures, including fetal surgery. In this context, maintaining visibility of medical devices is a significant challenge. Needles and catheters can readily deviate from the ultrasound imaging plane as they are inserted. When the medical device tips are not visible, they can damage critical structures, with potentially profound consequences including loss of pregnancy. In this study, we performed 3D ultrasonic tracking of a needle using a novel probe with a 1.5D array of transducer elements that was driven by a commercial ultrasound system. A fiber-optic hydrophone integrated into the needle received transmissions from the probe, and data from this sensor was processed to estimate the position of the hydrophone tip in the coordinate space of the probe. Golay coding was used to increase the signal-to-noise (SNR). The relative tracking accuracy was better than 0.4 mm in all dimensions, as evaluated using a water phantom. To obtain a preliminary indication of the clinical potential of 3D ultrasonic needle tracking, an intravascular needle insertion was performed in anin vivopregnant sheep model. The SNR values ranged from 12 to 16 at depths of 20 to 31 mm and at an insertion angle of 49° relative to the probe surface normal. The results of this study demonstrate that 3D ultrasonic needle tracking with a fiber-optic hydrophone sensor and a 1.5D array is feasible in clinically realistic environments.
authors.affiliation: Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Xia
authors.affiliation: Department of Anaesthesia, Main Theatres, Maple Bridge Link Corridor, Podium 3, University College Hospital, 235 Euston Road, London NW1 2BU, UK.
authors.forename: Simeon J
authors.initials: SJ
authors.lastname: West
authors.affiliation: GePaSud, University of French Polynesia, Faa'a 98702, French Polynesia.
authors.forename: Jean-Martial
authors.initials: JM
authors.lastname: Mari
authors.affiliation: Translational Imaging Group, Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, Wolfson House, London NW1 2HE, UK.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Ourselin
authors.affiliation: Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK.
authors.forename: Anna L
authors.initials: AL
authors.lastname: David
authors.affiliation: Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Adrien E
authors.initials: AE
authors.lastname: Desjardins
mesh_terms: D000465:Algorithms; D000818:Animals; D005260:Female; D005333:Fetus; D061705:Image-Guided Biopsy / Q000379:methods*; D009339:Needles; D019047:Phantoms, Imaging; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012756:Sheep; D014159:Transducers; D018084:Ultrasonography, Interventional / Q000379:methods*