A visualization system for simulating excavation of a fluid-structure interaction tunnel includes a fluid-structure interaction tunnel model system, a tunnel model solution supply system, a detection system and an excavation system. The tunnel model solution supply system is configured to inject a nuclide solution to simulate a fluid pressure. The detection system is configured to detect a 3D deformation state of a tunnel surrounding rock and a 3D migration process of the nuclide solution. The excavation system is provided between the detection system and the tunnel model system to simulate tunnel excavation. During the tunnel excavation, a lifting device in the excavation system controls a drilling device to ascend to a set height for operation. During 3D detection, the lifting device controls the drilling device to descend to an initial height to avoid affecting the detection of a detection device.

A virtual 511 KeV attenuation map is generated from CT data. Spectral or multiple energy CT is used to more accurately extrapolate the 511 KeV attenuation map. Since spectral or multiple energy CT may allow for material decomposition and/or due to additional information in the form of measurements at different energies, the modeling used to generate the 511 KeV attenuation map may better account for all materials including high density material. The extrapolated 511 KeV attenuation map may more likely represent actual attenuation at 511 KeV without requiring extra scanning using a 511 KeV source external to the patient. The virtual 511 KeV attenuation map (e.g., CT data at 511 KeV) may provide more accurate PET image reconstruction.

A radiation detector module including a scintillator element configured to generate optical signals in response to incident radiation. A photodetector is coupled to at least a first surface of the scintillator element, the photodetector configured to convert the optical signals into output characterizing the radiation. An acoustic array is coupled to at least a second surface of the scintillator element, the acoustic array configured to convert acoustic signals generated in the scintillator element into output characterizing acoustic energy deposited therein.

Detector module designs for radiographic imaging include first and second layers of scintillator rods or pixel arrays oriented in first and second directions. The first and second directions are transversely oriented to define a light sharing region between the first and second layers. Encoding features may be disposed in, on or between the first and second layers, and configured to modulate propagation of optical signals therealong or therebetween.

A method for normalization of a positron emission tomography (PET) scanner. The PET scanner includes a plurality of blocks. Each of the plurality of blocks includes a plurality of rows. Each of the plurality of rows includes a plurality of actual detectors and an unused area. The method includes acquiring a plurality of lines of response (LORs) by scanning a normalization phantom, obtaining a plurality of actual counts by extracting a plurality of LORs subsets from the plurality of LORs and counting a number of elements in each LORs subset, generating a plurality of virtual detectors in each of the plurality of rows by assigning the unused area to the plurality of virtual detectors, generating a count profile for the plurality of actual detectors, estimating a plurality of virtual counts based on the count profile, and applying a normalization process on the plurality of blocks.

A radiation detector module including a scintillator element configured to generate optical signals in response to incident radiation. A photodetector is coupled to at least a first surface of the scintillator element, the photodetector configured to convert the optical signals into output characterizing the radiation. An acoustic array is coupled to at least a second surface of the scintillator element, the acoustic array configured to convert acoustic signals generated in the scintillator element into output characterizing acoustic energy deposited therein.

Detector module designs for radiographic imaging include first and second layers of scintillator rods or pixel arrays oriented in first and second directions. The first and second directions are transversely oriented to define a light sharing region between the first and second layers. Encoding features may be disposed in, on or between the first and second layers, and configured to modulate propagation of optical signals therealong or therebetween.

Detector module designs for radiographic imaging include first and second layers of scintillator rods or pixel arrays oriented in first and second directions. The first and second directions are transversely oriented to define a light sharing region between the first and second layers. Encoding features may be disposed in, on or between the first and second layers, and configured to modulate propagation of optical signals therealong or therebetween.

Detector module designs for radiographic imaging include first and second layers of scintillator rods or pixel arrays oriented in first and second directions. The first and second directions are transversely oriented to define a light sharing region between the first and second layers. Encoding features may be disposed in, on or between the first and second layers, and configured to modulate propagation of optical signals therealong or therebetween.

Embodiments of the present disclosure provide a multi-physical field imaging method based on PET-CT and DAS, comprising: wrapping distributed acoustic sensors on a surface of a non-metallic sample to be tested, and then placing them in a pressure device; loading triaxial pressures; preparing a tracer fluid; pumping the tracer fluid into the non-metallic sample; collecting PET images and CT images of internal structure of the non-metallic sample, meanwhile, monitoring internal acoustic emission events of the non-metallic sample in real time; combining the PET images with the CT images, to obtain PET/CT images; locating the acoustic emission events, and obtaining occurrence time and spatial location of internal structural perturbations; and analyzing a mechanism of fluid-solid coupling effect in the non-metallic sample under loaded stress. The imaging method and system of the present disclosure can accurately and reliably image the fluid-solid coupling process in the material.