Shielded x-ray detector with improved image quality stability
AssigneeGE Precision Healthcare LLC
InventorsDouglas Albagli, William Hennessy, Robert Gallup, Benjamin Backes
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Abstract
The image quality and useful life of an x-ray imaging detector is enhanced by adding a shield layer between the photodiode/thin film transistor (TFT) array and the cesium iodide (CsI)-based scintillator/scintillator layer. The shield layer prevents dynamic charge coupling between a CsI/parylene layer located above the shield layer and the conductive data transfer lines located below the shield layer and operably connected to the individual pixels of the photodiode/TFT array to effectively maintain the level of various image quality parameters over time, including the modulation transfer function (MTF), and the Signal to Noise Ratio (SNR).
Claims20
An x-ray imaging detector comprising:
- a) a photosensor including at least one photosensitive element positioned over a substrate;
- b) a data transfer line positioned over the substrate and operably connected to the at least one photosensitive element;
- c) a dielectric layer disposed over the data transfer line and the at least one photosensitive element;
- d) a shield layer disposed on the dielectric layer over the data transfer line and the at least one photosensitive element;
- and
- e) a scintillator layer disposed on the shield layer opposite the dielectric layer.
An x-ray imaging detector comprising:
- a) a photosensor including at least one photosensitive element disposed over a substrate;
- b) a data transfer line disposed over the substrate and operably connected to the at least one photosensitive element;
- c) a first dielectric layer disposed between the substrate and the data transfer line
- d) a second dielectric layer disposed over the data transfer line;
- e) a shield layer disposed on the second dielectric layer opposite the data transfer line;
- and
- f) a scintillator layer disposed on the shield layer opposite the second dielectric layer.
An x-ray imaging system comprising:
- a) an x-ray source;
- b) an x-ray imaging detector positioned to receive radiation emitted from the x-ray source through an object positioned between the x-ray source and the x-ray imaging detector;
- and
- c) a system controller operably connected to the x-ray source and the x-ray detector to control the operation of the x-ray source and the x-ray imaging detector;
- the x-ray imaging detector comprising:
- i) a substrate;
- ii) read out electronics disposed on the substrate and operably connected to the system controller;
- iii) a photosensor disposed on the substrate and operably connected to the read out electronics, the photosensor comprising at least one photosensitive element and a data transfer line operably connected between the at least one photosensitive element and the read out electronics;
- iv) a dielectric layer disposed on the substrate over the data transfer line and the at least one photosensitive element;
- v) a shield layer disposed on the dielectric layer opposite the substrate over the data transfer line and the at least one photosensitive element;
- and
- vi) a scintillator layer disposed on the shield layer opposite the dielectric layer.
A method of forming an x-ray imaging detector comprising the steps of:
- a) forming an array of photosensitive elements on a substrate layer, each photosensitive element including a photodiode and a thin film transistor;
- b) forming data transfer lines on the substrate layer, the data transfer lines operably connected to each of the photosensitive elements;
- c) forming a dielectric layer over the array of photosensitive elements and the data transfer lines;
- d) forming a shield layer over and coextensive with the dielectric layer;
- e) forming a scintillator layer over the shield layer;
- and
- f) forming a sealing layer over the scintillator layer.
Dependencies are inferred from the claim text.