A Patient-Specific Mixed-Reality Visualization Tool for Thoracic Surgical Planning.
The Annals of thoracic surgery
Imaging of magnetic ink patterns via off-resonance sensitivity.
Magnetic resonance in medicine
Identifying small lung lesions during minimally invasive thoracic surgery can be challenging. We describe 3D mixed-reality visualization technology that may facilitate non-invasive nodule localization.A software application and medical image processing pipeline were developed for the Microsoft HoloLens to incorporate patient-specific data and provide a mixed-reality tool to explore and manipulate chest anatomy with a custom-designed user interface featuring gesture and voice recognition.A needs assessment between engineering and clinical disciplines identified the potential utility of mixed-reality technology in facilitating safe and effective resection of small lung nodules. Through an iterative process, we developed a prototype employing a wearable headset that allows the user to: (1) view a patient's original preoperative imaging, (2) manipulate a 3D rendering of that patient's chest anatomy including the bronchial, osseus, and vascular structures, and (3) simulate lung deflation and surgical instrument placement.Mixed-reality visualization during surgical planning may facilitate accurate and rapid identification of small lung lesions during minimally invasive surgeries and reduce the need for additional invasive pre-operative localization procedures.
View details for DOI 10.1016/j.athoracsur.2020.01.060
View details for PubMedID 32145195
Printed magnetic ink creates predictable B0 field perturbations based on printed shape and magnetic susceptibility. This can be exploited for contrast in MR imaging techniques that are sensitized to off-resonance. The purpose of this work was to characterize the susceptibility variations of magnetic ink and demonstrate its application for creating MR-visible skin markings.The magnetic susceptibility of the ink was estimated by comparing acquired and simulated B0 field maps of a custom-built phantom. The phantom was also imaged using a 3D gradient echo sequence with a presaturation pulse tuned to different frequencies, which adjusts the range of suppressed frequencies. Healthy volunteers with a magnetic ink pattern pressed to the skin or magnetic ink temporary flexible adhesives applied to the skin were similarly imaged.The volume-average magnetic susceptibility of the ink was estimated to be 131?±?3 parts per million across a 1-mm isotropic voxel (13,100 parts per million assuming a 10-?m thickness of printed ink). Adjusting the saturation frequency highlights different off-resonant regions created by the ink patterns; for example, if tuned to suppress fat, fat suppression will fail near the ink due to the off-resonance. This causes magnetic ink skin markings placed over a region with underlying subcutaneous fat to be visible on MR images.Patterns printed with magnetic ink can be imaged and identified with MRI. Temporary flexible skin adhesives printed with magnetic ink have the potential to be used as skin markings that are visible both by eye and on MR images.
View details for PubMedID 29603366