Disclosed herein is a radiation detector, comprising: an avalanche photodiode (APD) with a first side coupled to an electrode and configured to work in a linear mode; a capacitor module electrically connected to the electrode and comprising a capacitor, wherein the capacitor module is configured to collect charge carriers from the electrode onto the capacitor; a current sourcing module in parallel to the capacitor, the current sourcing module configured to compensate for a leakage current in the APD and comprising a current source and a modulator; wherein the current source is configured to output a first electrical current and a second electrical current; wherein the modulator is configured to control a ratio of a duration at which the current source outputs the first electrical current to a duration at which the current source outputs the second electrical current.

According to a method, first magnetic resonance signals are captured at a first time point. Second magnetic resonance signals are captured at a second time point. The first magnetic resonance signals are provoked by nuclear spin excitations of fat and water in an examination object. The second magnetic resonance signals are provoked by nuclear spin excitations of fat and water in the examination object. The nuclear spin excitations of fat and water are in phase at the first time point. The nuclear spin excitations of fat and water are in opposed phase at the second time point. A Bo field map is determined based on the first magnetic resonance signals and the second magnetic resonance signals. Further magnetic resonance signals are captured. At least one magnetic resonance mapping is determined by reconstructing the further magnetic resonance signals. The at least one magnetic resonance mapping is corrected based on the Bo field map.

Disclosed herein is a radiation detector, comprising: an avalanche photodiode (APD) with a first side coupled to an electrode and configured to work in a linear mode; a capacitor module electrically connected to the electrode and comprising a capacitor, wherein the capacitor module is configured to collect charge carriers from the electrode onto the capacitor; a current sourcing module in parallel to the capacitor, the current sourcing module configured to compensate for a leakage current in the APD and comprising a current source and a modulator; wherein the current source is configured to output a first electrical current and a second electrical current; wherein the modulator is configured to control a ratio of a duration at which the current source outputs the first electrical current to a duration at which the current source outputs the second electrical current.

A hybrid collimated probe incorporates two detectors consisting of a scintillating crystal or semiconductor material, such as Cadmium-Zinc-Telluride (CZT). The count rate measured on the rear detector is corrected for the shielding effect of the front detector before the count rate ratio is calculated. This is done by multiplying the rear detector count rate by a factor pre-determined from the thickness and density of the front detector for a specific radionuclide energy. The count rate ratio also must be corrected for the presence of background radiation at the target site. This is done by taking a 3 second average of the count rate over tissue that does not contain a radiotracer sequestered at the site of pathology, but in adjacent tissue that is uniformly perfused by a lower level concentration of the radiotracer circulating in the blood pool background.

A system for performing radiation treatment of a patient with a proton beam from a particle accelerator uses a high-sensitivity camera to capture dose images of patient surface, a video processor that integrates the dose images, beam-on detection apparatus, and apparatus to eliminate interference of room lighting. In embodiments, the system registers dose images to a surface model of the patient derived from stereo image pairs captured by a stereo camera. In embodiments, the surface model is registered to three-dimensional images of the patient from MRI or CT, and an integrated three-dimensional energy deposition map of the patient is prepared.

Improved imaging devices and methods. A portable SPECT imaging device may co-register with imaging modalities such as ultrasound. Gamma camera panels including gamma camera sensors may be connected to a mechanical arm. A coded aperture mask may be placed in front of a gamma-ray photon sensor and used to construct a high-resolution three-dimensional map of radioisotope distributions inside a patient, which can be generated by scanning the patient from a reduced range of directions around the patient and with radiation sensors placed in close proximity to this patient. Increased imaging sensitivity and resolution is provided. The SPECT imaging device can be used to guide medical interventions, such as biopsies and ablation therapies, and can also be used to guide surgeries.

A system for generating MR images for segmentation and/or use in correcting attenuation in subsequent images using other modalities (e.g., PET, SPECT, etc.) is described. A surrogate soft tissue device is provided and positioned on the patient near the artifact source to provide a surrogate soft tissue boundary that can be imaged and interpreted during segmentation to mitigate the deleterious effects of a local susceptibility artifact in the MR image.

Techniques are disclosed for systems and methods to provide a radiation detector module for a radiation detector. A radiation detector module includes a metallic and/or metalized enclosure, a radiation sensor disposed within the enclosure, readout electronics configured to provide radiation detection event signals corresponding to incident ionizing radiation in the radiation sensor, and a cap including an internal interface configured to couple to the readout electronics and an external interface configured to couple to a radiation detector, where the cap is configured to hermetically seal the radiation sensor within the enclosure. The cap may be implemented as an edge plated printed circuit board (PCB) including a slot configured to mate with a planar edge of an open surface of the enclosure, where the slot is soldered to the planar edge of the enclosure to hermetically seal the radiation sensor within the enclosure.

An intraoperative imaging system combines a gamma probe and an ultrasound probe. The probes are linked to provide co-registration of gamma radiation detected by the gamma probe with an image acquired by the ultrasound probe. The gamma probe has a converging collimator made of a metal block having a plurality of channels therein, which converge from an output face toward an input face. Each channel extends between and opens out at the faces such that openings at the input face have smaller cross-sectional areas than openings at the output face so that each channel tapers inwardly from the output face to the input face. The collimator has an external focal point distant from the input face. The system improves identification and localization of cancerous cells, facilitating more accurate biopsy data and more complete surgical resection. The gamma probe increases sensitivity, while maintaining spatial resolution, and increasing depth of view.

Systems and methods include generation of a source optical signal outside of a radiofrequency-shielded cabin based on a reference electrical clock signal, transmission of the source optical signal into the radiofrequency-shielded cabin via optical media, generation of an electrical clock signal based on the source optical signal within the radiofrequency-shielded cabin, jitter cleaning of the electrical clock signal within the radiofrequency-shielded cabin to generate a jitter-cleaned electrical clock signal based on an average frequency of the electrical clock signal and a jitter of a magnetically-compatible jitter cleaner oscillator, and transmission of the jitter-cleaned electrical clock signal to a plurality of positron emission tomography scanner detectors disposed within the radiofrequency-shielded cabin.