System and method for determining local attenuation for ultrasonic imaging
First Claim
1. A method for determining local attenuation of an interrogation region scanned by an ultrasonic imaging system comprising the following steps:
- A. scanning by ultrasound an interrogation region in an axial direction and a lateral direction;
B. sensing backscattered ultrasonic echoes from the interrogation region;
C. grouping the backscattered echoes as a two-dimensional pattern of image elements;
D. generating a two-dimensional table of envelope power values corresponding to a plurality of rows and columns of the pattern of image elements; and
E. in a processing mode;
1) grouping the image elements in the interrogation region into a two-dimensional pattern of processing windows, each window being divided into window rows that extend in the lateral direction and window columns that extend in the axial direction;
2) for each window row of each processing window, generating an average positional power value;
3) generating a window attenuation coefficient corresponding to a decay parameter of a non-linear decay model of local attenuation of the interrogation region as a non-linear function of the average positional power values for each row in the processing window.
1 Assignment
0 Petitions
Accused Products
Abstract
Power values of backscattered ultrasonic echoes from an interrogation region of a patient'"'"'s body are stored in a 2-D envelope table. The region is thereby represented as a 2-D pattern of image elements. In a processing mode, these elements are grouped into processing windows. After row averaging of the power values for each window, a window attenuation coefficient is generated corresponding to a decay parameter of a non-linear decay model of local attenuation of the interrogation region as a non-linear function of the average positional power values for each row in the processing window. The coefficients are then used to scale the power values before scan conversion and display, and thus to compensate for local attenuation. The invention can also test for tissue heterogeneity by first defining convergence and non-convergence criteria. A rationalized gain control processor then iteratively estimates the window attenuation coefficients until either criterion is met. The RGC processor then indicates heterogeneity of tissue in the corresponding processing window of the interrogation when the non-convergence criterion is met.
28 Citations
8 Claims
-
1. A method for determining local attenuation of an interrogation region scanned by an ultrasonic imaging system comprising the following steps:
-
A. scanning by ultrasound an interrogation region in an axial direction and a lateral direction; B. sensing backscattered ultrasonic echoes from the interrogation region; C. grouping the backscattered echoes as a two-dimensional pattern of image elements; D. generating a two-dimensional table of envelope power values corresponding to a plurality of rows and columns of the pattern of image elements; and E. in a processing mode; 1) grouping the image elements in the interrogation region into a two-dimensional pattern of processing windows, each window being divided into window rows that extend in the lateral direction and window columns that extend in the axial direction; 2) for each window row of each processing window, generating an average positional power value; 3) generating a window attenuation coefficient corresponding to a decay parameter of a non-linear decay model of local attenuation of the interrogation region as a non-linear function of the average positional power values for each row in the processing window. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A system for determining local attenuation of an interrogation region scanned by an ultrasonic imaging system comprising:
-
A. an ultrasonic transmission means for scanning by ultrasound an interrogation region in an axial direction and a lateral direction; B. an ultrasonic reception means; 1) for sensing backscattered ultrasonic echoes from the interrogation region; 2) for grouping the backscattered echoes as a two-dimensional pattern of image elements; 3) for generating and storing in a memory a two-dimensional table of envelope power values corresponding to a plurality of rows and columns of the pattern of image elements; and 4) in a processing mode; a) for grouping the image elements in the interrogation region into a two-dimensional pattern of processing windows, each window being divided into window rows that extend in the lateral direction and window columns that extend in the axial direction; b) for each window row of each processing window, for generating an average positional power value; c) for generating a window attenuation coefficient corresponding to a decay parameter of a nonlinear decay model of local attenuation of the interrogation region as a non-linear function of the average positional power values for each row in the processing window. - View Dependent Claims (7, 8)
-
Specification