CT scanning X-ray source tube current modulating method and computed tomography device

Abstract

The invention provides a CT scanning X-ray source tube current modulating method and a computed tomography device. The method comprises the following steps: determining a heartbeat cycle in accordance with electrocardiogram signals, wherein each heartbeat cycle comprises a first period that cardiac motion is gentle and a second period that the cardiac motion is vigorous; determining target tube current within the second period of the current heartbeat cycle in accordance with tube current at the end of the period of the current heartbeat cycle which is determined in advance, tube current at the beginning of the first period of a next heartbeat cycle and pre-saved X-ray source characteristics; and controlling tube current of the X-ray source within the second period of the current heartbeat cycle, wherein the tube current within the second period of the current heartbeat cycle is greater than or equal to the target tube current and is less than tube current within the first periods of the current heartbeat cycle and the next heartbeat cycle. With the application of the method provided by the invention, an X-ray radiation dose on an examined object in CT scanning can be effectively reduced.

Description

【Technical field】 [0001] The invention relates to the technical field of computed tomography (CT, Computed Tomography), in particular to a CT scan X-ray source tube current modulation method and a computed tomography device. 【Background technique】 [0002] Computed Tomography (CT for short) uses X-rays to scan specific parts of the human body at a certain thickness. Since different human tissues have different absorption capabilities for X-rays, a computer can be used to reconstruct images of the fault plane. [0003] figure 1 is a schematic diagram of the structure of a computed tomography system, such as figure 1 As shown, computed tomography system 100 includes a gantry 110 having a rotatable portion 130 that rotates about a system axis. The rotatable part 130 has an x-ray system of an x-ray source 131 and an x-ray detector 132 arranged opposite to each other. There is also an examination table 120 on which the subject can be pushed into the scanning cavity 133 along t...

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Problems solved by technology

[0007] Although a lower X-ray radiation dose is used when the cardiac motion of the cardiac scan is large, due to the limitation of the hardware modulation capability of the X-ray source, it takes a certain time for the tube current of the X-ray source to rise or fall, so in order to It is ensured that the tube current of the X-ray source can reach a higher X-ray radiation dose (full power) at the beginning of a period of large heart motion. In the prior art, a preset conservative power is used when the heart motion is large. X-ray source tube current value, which will make the patient receive unnecessary additional X-ray radiation

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