| Category | Computer Science and Engineering |
| Keywords | CT Scanning, needle, sparse scan sampling, spherical market |
| Current development stage | TRL4 Technology validated in lab |
Application
Interventional CT procedures, e.g. lungs, liver, and prostate lesion biopsies, aspiration, drainage, brachytherapy, cryotherapy and thermal ablation, are nowadays pervasive. In these procedures, the patient lies on the CT gantry and is repeatedly scanned to help the surgeon track the anatomy and the surgical tool, e.g., a needle.
The main drawback of existing image-based needle CT-guided methods is the X-ray radiation exposure due to repeated, time-consuming, scanning required to monitor the needle placement, that may be harmful to the patient and staff. This limits the number of scans that can be acquired, thereby restricting the surgeon’s control over the needle. This may cause missing the target, misdiagnosis, and/or small lesions not to be considered for biopsy.
In addition, accuracy suffers most due to image reconstruction, metal artifacts that obscure the needle tip and trajectory, patients can be uncooperative, and scanned organs can be prone to respiratory motion, such as the lung and liver.
Various techniques are currently available for interventional needle procedures, including ultrasound imaging, X-ray fluoroscopy, CT scanning with optical guidance or tracking of manual insertion. None of the technologies provides a satisfactory solution.
Our Innovation
A new method for imageless needle and patient tracking in interventional CT procedures based on fractional CT scanning, enabling to accurately locate the surgical needle with respect to the patient anatomy in the CT scanner. It also allows sparse scan sampling, without reconstructing the CT image.
Support frequent and accurate needle and needle tip localization with respect to the patient.
Reduce the radiation dose by two orders of magnitude of a full CT scan without additional hardware or setup, enabling significantly less radiation for the same amount of needle locations, in addition to a considerable increase in needle locations for the same amount of radiation.
No in-plane needle location is required.
Fully automatic, no calibration and/or manual setup.
The patient does not require immobilization.
Technology
The key principle is to detect the needle and attached spherical marker in projection (sinogram) space based on the strongly attenuated X-ray signal due to the metallic composition of the needle, the needle’s thin cylindrical geometry, and the marker’s spherical geometry.
A transformation from projection space to physical space uniquely determines the location and orientation of the needle and the needle tip position. Our method works directly in projection space and simultaneously performs patient registration and needle localization for every fractional CT scanning acquisition using the same sparse set of views.
The needle location is performed directly in 3D Radon space using the raw sparse sinogram data produced by the CT scanner.
Opportunity
General interventional CT needle tracking and patient packages.
Specialized packages for intra-procedural CT scanning tailored to specific diseases, pathologies, organs, and procedures.
Disposable needle and tracking markers for interventional CT procedures.
Suitable for both existing and future CT scanners
PATENT STATUS
Granted US 11,109,822
