Imaging detector with anti-aliasing filter in the readout electronics and/or photosensor

#The following generally relates to an imaging detector and more particularly to an imaging detector with anti-aliasing filter in the readout electronics and/or photosensor and is described in connection with computed tomography (CT).

#A CT scanner generally includes an x-ray tube mounted on a rotatable gantry that rotates around an examination region about a z-axis. The x-ray tube emits radiation that traverses the examination region. A detector array subtends an angular arc opposite the examination region from the x-ray tube, detects radiation that traverses the examination region, and generates a signal indicative thereof. A reconstructor processes the signal and reconstructs volumetric image data indicative thereof the examination region and a portion of a subject or object located therein during scanning.

#The CT detector array described in U.S. Pat. No. 6,510,195 to Chappo et al. includes one or more rows of detector tiles. Each detector tile includes a scintillator layer optically coupled to a two-dimensional (2D) back-illuminated photodiode array of detector pixels (e.g., 16 or more). The photodiode array is bonded on a carrier substrate via bump bonding. Readout electronics packaged in an application specific integrated chip (ASIC) are also bonded on the carrier substrate. The carrier substrate includes electrodes that route signals produced by the detector pixels to the readout electronics.

#The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention.

#FIG. 1 depicts a portion of a prior art imaging detector ASIC without electrical isolation between analog and digital readout electronics and the substrate.

#FIG. 2 depicts a portion of a prior art imaging detector ASIC in which analog and digital readout electronics are electrically isolated from each other and the substrate through a common analog well and a common digital well.

#In initially referring to FIG. 4, an imaging system 400, such as a computed tomography (CT) scanner, is illustrated. The imaging system 400 includes a generally stationary gantry 402 and a rotating gantry 404. The rotating gantry 404 is rotatably supported by the stationary gantry 402 and rotates around an examination region 406 about a longitudinal or z-axis. A radiation source 408, such as an x-ray tube, is supported by and rotates with the rotating gantry 404, and produces a generally cone, fan, wedge, or otherwise shaped radiation beam that traverses the examination region 406.

#A radiation sensitive detector array 412 subtends an angular arc opposite the radiation sources 408 across the examination region 406 and detects radiation traversing the examination region 406. The radiation sensitive detector array 412 includes one or more rows 416 of detector tiles 418, the rows 416 arranged with respect to each other along the z-axis. The detector tiles 418 are coupled to detector modules 419, via solder balls, stud bumps, and/or otherwise, which are mounted in the system 400, arranged with respect to each other along the z-axis. Briefly turning to FIG. 5, a non-limiting example of a detector tile 418 is illustrated. For clarity and explanatory purposes, the tile 418 is shown in an exploded view in which various components thereof are separated from each other.

#The tile 418 includes a scintillator layer 420 optically coupled to a photosensor 422, which includes a plurality of photosensitive areas (detector pixels) 424 within a non-photosensitive area 426 on a first side 428 of the photosensor 422. The illustrated photosensor 422 is a back-illuminated photosensor with electrodes (not visible) that inter-connect the detector pixels 424 to bonding pads or the like (not visible) located on a second opposing side 430 of the photosensor 422. In another embodiment, the photosensor 422 is a front-illuminated photosensor with vias that route the signals from the first side 428 to the pads on the opposing side 430. The scintillator layer 420 may include a plurality of scintillator pixels, each corresponding to one of the detector pixels 424.