Jul 6, 2012
Innovation: patent applications review
A round-up of the latest international patent applications in medical imaging.
PET and CT share a single detector
Philips Electronics of the Netherlands has designed a PET/CT system that uses a single detector for both modalities, improving and simplifying image registration (WO/2012/066469). The detector comprises two layers encircling the examination region. The first layer incorporates scintillators and light detectors such as avalanche photodiodes. The second layer includes optical detectors and scintillators with a larger cross-section than those in the first layer. A group of nine (for example) first-layer scintillators overlay each scintillator in the second layer. The first layer detects transmission radiation and generates a CT image with relatively high resolution, while the second-layer detectors detect PET emission signals for reconstruction into a lower-resolution emission image. As the detectors in the two layers are aligned, the transmission and emission images are inherently aligned.
MRI methods separate malignant and benign tumours
An MR-based method for distinguishing benign and malignant tumours in soft tissues, particularly breast tissue, is detailed by the Sunnmøre MR-Klinikk in Norway (WO/2012/070951). The process involves registration and comparison of data from dynamic contrast-enhanced (DCE) MR and dynamic susceptibility contrast-enhanced (DSC) MR images of the tumours. A computer program is adjusted to initially perform two dynamic MRI pulse sequences in an interleaved mode during administration of an MR contrast. One pulse sequence is optimized for high spatial resolution and the other for high temporal resolution. The high-temporal dissolved sequence further comprises a double echo-collection that's sensitive to both DCE and DSC. This generates a number of biomarkers, such as pharmacokinetic, descriptive DCE and descriptive DSC biomarkers. Subsequently, these data are normalized and compared with corresponding data from benign and malignant tumours.
On-site accelerator enhances SPECT exams
Radioisotopes required for SPECT are currently produced centrally in a few institutes. Due to the duration of transport from the production location to the location of the SPECT examination, the selected isotope must have a relatively slow decay rate to remain sufficiently active at the time of the exam. In international patent application WO/2012/049004, Siemens of Germany describes the use of an ONIAC particle accelerator to produce the radioisotope. This accelerator has a very small size and can therefore be installed in the same building as the SPECT scanner to produce radioisotopes on site. The filing notes that such radioisotopes can have a high decay rate, due to the insignificant transport time, and that the SPECT image quality can be substantially improved accordingly.
Encapsulated radionuclides made for PET
A team from the Technical University of Denmark has developed a novel means of creating PET imaging compositions. International patent application WO/2012/079582 describes a class of diagnostic compounds comprising liposome compositions with encapsulated metal entities and/or radionuclides, such as 61Cu and 64Cu isotopes. The filing presents an improved method for loading the delivery systems with the radionuclides, and also describes the use of liposomes for targeted diagnosis and treatment of a target site, such as cancerous tissue and general pathological conditions associated with leaky blood vessels.
Tomography system exploits Cerenkov effect
Researchers at the Chinese Academy of Sciences have published details of a tomography system based on the Cerenkov effect (WO/2012/083503). The device includes a Cerenkov luminescence detector for collecting a plane optical image; an imaging apparatus for collecting a three-dimensional structural image; a bed to support the imaged object; and a computer, for forming the plane optical image, the three-dimensional structure image and the Cerenkov luminescence tomography image. According to the filing, the application re-establishes Cerenkov luminescence tomography in the whole range by coupling a high-order simplified spherical harmonics approximation module and iterative half-threshold operators, so as to quickly realize the three-dimensional distribution of radiopharmaceuticals or molecular probes in the body.
Imaging unit tailors radiography method to breast density
A means to determine an appropriate method for breast radiography while suppressing exposure dose is described by Fujifilm of Japan (WO/2012/090472). The scheme involves reading past radiographic data of the breast from an image database, and using these data to calculate the mammary gland density. An imaging method selection unit selects two-dimensional imaging when the mammary gland density is no greater than a first threshold and selects three-dimensional imaging when the density exceeds this threshold. The selected imaging method is then output to the radiography device.
About the author
Tami Freeman is editor of medicalphysicsweb.