A round-up of the latest international patent applications in medical imaging.
Fusion images guide interventional procedures
GE has developed a system that obtains fusion images of a patient’s anatomy for use in guiding interventional medical procedures (WO/2018/112063). The technique fuses fluoroscopy images taken during the interventional procedure with pre-operative CT angiography (CTA) images, in real-time. This enables the operator to see the anatomy in the fluoroscopy image without having to inject contrast agent. To correct for anatomical deformation due to the insertion of interventional devices, a 3D ultrasound image is obtained after insertion and used to correct the pre-operative CTA images and provide the current vascular anatomy. This updated CTA image is fused with the intra-operative fluoroscopy images to provide an accurate 3D roadmap image that matches the deformed anatomy.
Time-of-flight detects, corrects PET/CT misalignment
Philips has devised a scheme for using time-of-flight (TOF) to detect and correct misalignment between PET imaging data and the attenuation map in PET/CT images (WO/2018/127470). The described device performs TOF image reconstruction (which utilizes the TOF localization of the PET imaging data) on PET data to produce a TOF-reconstructed image. Non-TOF image reconstruction, which does not utilize the TOF localization, is also performed. The device then computes a comparison image, which indicates differences between the TOF and non-TOF reconstructions. An adjustment – such as alignment correction of an attenuation map – is determined based on the comparison image. The TOF image reconstruction is then repeated on the PET data with the determined adjustment, resulting in an adjusted TOF-reconstructed image.
Ultrasound delivers non-invasive blood pressure measurement
Physio-Control has described a method and apparatus for non-invasive measurement of instantaneous blood pressure using pulse wave velocity (WO/2018/136135). A measurement component containing one or more sensors (such as ultrasound sensors) is fixed to the patient near to a blood vessel. This device simultaneously measures the vessel’s pulse wave velocity and the instantaneous blood velocity within the vessel. It then computes the instantaneous blood pressure of the vessel using, for example, the Waterhammer equation. The filing notes that the sensors may be contained in a disposable patch or co-located with another sensor, such as a patient monitor.
X-ray device generates multi-energy images
Varian Medical Systems has published details of a device for multi-energy X-ray imaging (WO/2018/132284). The system includes an X-ray source, which generates a series of individual X-ray pulses with different energy levels, and an X-ray imager that detects the received X-rays for generation of a composite image. It also incorporates a generator interface box (GIB) that controls the source to provide the series of individual X-ray pulses and synchronizes detection with pulse generation. The GIB controls these processes to optimize image generation while minimizing unnecessary X-ray irradiation.
OCT provides low-cost central nervous system characterization
Researchers at the University of Coimbra have created a data processing method for characterizing the health status of the central nervous system, based on non-invasive optical coherence tomography (OCT) of the retina (WO/2018/127815). The technique involves processing OCT fundus imaging data to compute a texture parameter(s), and then classifying the texture parameter(s) into a central nervous system health status. The method, which uses a low-cost and compact acquisition device, overcomes the need for expensive and complex MR and CT instrumentation to assess central nervous system status in humans and animals. It enables classification of healthy controls and patients into the correct group and monitoring of longitudinal changes, in a fraction of the previous time and at lower cost.
SPECT images processed with improved resolution isotropy
A method for processing a SPECT image with improved resolution isotropy is disclosed by Molecular Dynamics in patent application WO/2018/146691. The image is obtained using at least one gamma detector that detects gamma radiation emerging from the region-of-interest at multiple detector configurations. The method includes: obtaining data indicative of the detector configurations and their spatial relationships to the region-of-interest; using these data to determine a resolution level for each of a number of directions in each point in the image; and processing the image based on the determined resolution levels.