Unlock instant, AI-driven research and patent intelligence for your innovation.

X-ray CT apparatus

An X-ray and X-ray tube technology, applied in the field of X-ray CT devices, can solve unexplored and different problems

Inactive Publication Date: 2011-01-12
HITACHI MEDICAL CORP
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0015] Furthermore, the CNR that should be achieved differs depending on the size of the diagnostic object, so the X-ray conditions that should be set are also different, but this point has not been discussed

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • X-ray CT apparatus
  • X-ray CT apparatus
  • X-ray CT apparatus

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 2

[0217] Figure 11 This is a flowchart of a series of operations for pre-scanning preparatory operations for determining the optimum X-ray conditions in the second embodiment. Hereinafter, the procedure for determining the X-ray conditions will be described in detail using the flowcharts of operations.

[0218] The main difference between this embodiment and Embodiment 1 is that (a) when calculating the recognizable CNR, in addition to the size of the diagnostic object, the true positive rate and the false positive rate are also used; (b) the pre-calculated image SD is used The relationship between the tube current time product mAs and the tube current time product mAs is obtained to obtain the tube current time product mAs that realizes the recognizable CNR regardless of the tube voltage, and the tube current time product mAs is approximately constant to correct the obtained tube current time product mAs. By adopting (a), recommended imaging conditions can be calculated from r...

Embodiment 3

[0284] Figure 19 It is a flow chart of a series of operations performed before scanning for determining the optimum X-ray conditions in Embodiment 3. Hereinafter, the process of determining the X-ray conditions will be described in detail using this flow chart of operations.

[0285] In this embodiment, instead of obtaining the CNR from the relationship between the size of the diagnostic object and the CNR as in Embodiment 2, and then obtaining the SD of the reference slice position from the CNR, the difference lies in that the operator sets the target SD as the target, from The relationship between the size of the diagnostic object and the CNR calculates the recognizable size of the diagnostic object. The present embodiment has an advantage that imaging conditions based on CNR can be set by input similar to the conventionally used method of setting imaging conditions by inputting an image SD.

[0286] (1) The processing of positioning scanning photography (S400), scanning a...

Embodiment 4

[0321] Figure 21 It is a flow chart of a series of operations performed before scanning for determining the optimal X-ray conditions in Embodiment 4. Hereinafter, the steps of determining the X-ray conditions will be described in detail using this flow chart of operations.

[0322] In Examples 1 to 3, first, the tube voltage and tube current (or tube current time product) are calculated at the slice position (refer to the slice position) where the SD value becomes the maximum in the specific slice range, but in this example, Instead of using the slice position with the maximum SD value as a reference, it differs from the above-described embodiment in that the operator designates a desired slice position. Therefore, in this embodiment, the processing is different depending on whether the calculated CNR is applicable to all slices.

[0323] (1) The processing of positioning scanning photography (S500), scanning area setting, imaging condition input (S501), positioning scanning...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

An X-ray CT apparatus is provided, having a function for deciding an X-ray imaging condition prior to scanning, the X-ray imaging condition allowing an acquisition of contrast to noise ratio appropriate for identifying a diagnostic object. Prior to the real scan, a three-dimensional model of an object is estimated from scanogram projection data of the object, a contrast to noise ratio enabling identification of the diagnostic object is calculated, based on the diagnostic object size set by an operator via an operating device when planning the scan, the three-dimensional model, and a standard imaging condition that is stored in a storage device. Then, an optimum irradiated X-ray condition (tube current and tube voltage) is calculated for achieving the contrast to noise ratio enabling identification. The X-ray condition being calculated is displayed in the form of information such as image SD value and exposure dose, under the calculated X-ray condition and under other condition.

Description

technical field [0001] The present invention relates to an X-ray CT apparatus, and more particularly, to an X-ray CT apparatus having X-ray conditions predetermined before scanning to obtain a contrast-to-noise ratio suitable for identifying a diagnostic object. Background technique [0002] Among the X-ray CT apparatuses, there are single-slice X-ray CT apparatuses that obtain one tomographic image with one X-ray irradiation, and multi-slice X-ray CT apparatuses that simultaneously obtain a plurality of tomographic images. [0003] The single-slice X-ray CT apparatus uses an X-ray detector in which a plurality of X-ray detection elements are arranged in one row, that is, in a one-dimensional direction (channel direction), and irradiates a subject with a fan beam (fan beam) from an X-ray tube. ) is a fan-shaped X-ray beam, and X-rays transmitted through the subject are measured to obtain projection data of the subject. [0004] The multi-slice type X-ray CT device irradiate...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): A61B6/03
CPCA61B6/032A61B6/542A61B6/545
Inventor 广川浩一后藤大雅菅谷嘉晃宫崎靖
Owner HITACHI MEDICAL CORP