Scanning method and device with reduced scanning dosage

Patent metadata

Field	Value
Publication number	US-9351700-B2
Application number	US-201314142951-A
Country	US
Kind code	B2
Filing date	Dec 30, 2013
Priority date	Sep 26, 2013
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A scanning method and device are provided. The method includes: determining values for a first scanning dosage and a second scanning dosage used in a scanning process based on a trigger condition which varies regularly and attenuation fluctuations of an object to be scanned, wherein the first scanning dosage is higher than the second scanning dosage, and at least one of the first scanning dosage and the second scanning dosage has an inconstant value; and scanning a target position with the determined values. In the present disclosure, a scanning dosage may be reduced and different image noises may be kept consistent.

First claim

What is claimed is:

1. A computed tomography (CT) scanning method, comprising:
determining values for a first scanning dosage and a second scanning dosage used in a scanning process based on a trigger condition which varies regularly and attenuation fluctuations of an object to be scanned, wherein the first scanning dosage is higher than the second scanning dosage, and at least one of the first scanning dosage and the second scanning dosage has an inconstant value;
scanning a target position with dosages at the determined values;
during a transition process from the first scanning dosage stage to the second scanning dosage stage, implementing real-time calculation to obtain a time period for transition from a current scanning dosage to an initial scanning dosage in a third scanning dosage stage performed after the second scanning dosage stage;
implementing real-time comparison between the calculated time period and a preset time period; and
if the calculated time period is longer than or equal to the preset time period, terminating the transition process from the first scanning dosage stage to the second scanning dosage stage, terminating the second scanning dosage stage, and transitioning to the third scanning dosage stage from a current time point.

2. The method according to claim 1 , wherein when the first scanning dosage has an inconstant value, the second scanning dosage has a constant value which is determined according to the trigger condition which varies regularly.

3. The method according to claim 1 , wherein when the second scanning dosage has an inconstant value, the first scanning dosage has a constant value which is determined according to the trigger condition which varies regularly.

4. The method according to claim 1 , wherein when the second scanning dosage has an inconstant value, the step of determining values for a first scanning dosage and a second scanning dosage used in a scanning process based on a trigger condition which varies regularly and attenuation fluctuations of an object to be scanned comprises:
determining to use the inconstant second scanning dosage to scan the target position according to the trigger condition which varies regularly; and
adjusting the second scanning dosage to be a dosage which varies with the target position or varies with the target position and a scanning angle based on a dosage adjustment mode to ensure image noise congruence.

5. The method according to claim 1 , wherein when the first scanning dosage has an inconstant value, the step of determining values for a first scanning dosage and a second scanning dosage used in a scanning process based on a trigger condition which varies regularly and attenuation fluctuations of an object to be scanned comprises:
determining to use the inconstant first scanning dosage to scan the target position according to the trigger condition which varies regularly; and
adjusting the first scanning dosage to be a dosage which varies with the target position or varies with the target position and a scanning angle based on a dosage adjustment mode to ensure image noise congruence.

6. The method according to claim 4 , wherein the step of adjusting the second scanning dosage to be a dosage which varies with the target position or varies with the target position and a scanning angle based on a dosage adjustment mode to ensure image noise congruence comprises:
calculating a first set of dosage values for the second scanning dosage based on equation

N
j

=

DoseRightFactor
×

N
low

×

(

ⅇ

(

-

μ
water

*

D
ref

)

ⅇ

(

-

μ
water

*

D
j

)

)

adjCoef

,

wherein the first set of dosage values are used for scanning different target positions; and
calculating a second set of dosage values for the second scanning dosage based on equation

N
i

=

N
j

∑

i
=
1

V

⁢

A

max
,
i

*

A

max
,
i

,

wherein the second set of dosage values are used for scanning one target position from different scanning angles,
wherein N j is a scanning dosage on a j th target position, DoseRightFactor is an image noise coefficient, N low is the second scanning dosage, μ water is an attenuation coefficient of water, D ref is a referenced equivalent diameter of a water phantom, D j is an equivalent diameter of the water phantom on the j th target position, adjCoef is an exponent adjustment parameter of a current in a tube filament, N i is a scanning dosage of a i th scanning angle on the j th target position, A max,i is maximum attenuation of all channels of the i th scanning angle, and V is the total number of scanning angles in a round of scanning.

7. The method according to claim 5 , wherein the step of adjusting the first scanni

Assignees

• Shenyang Neusoft Medical Sys

Inventors

• Li Xinliang
• Pang Ling
• Lou Shanshan

Classifications

• A61B6/5258

  involving detection or reduction of artifacts or noise · CPC title

• A61B6/405

  Source units specially adapted to modify characteristics of the beam during the data acquisition process (A61B6/4021, A61B6/4035 take precedence) · CPC title

• A61B6/583 Primary

  using calibration phantoms · CPC title

• H05G1/40

  using adjustable time-switch · CPC title

• A61B6/503

  for diagnosis of the heart · CPC title