Ultrasound Imaging Apparatus

Abstract

An ultrasound imaging apparatus comprising a plurality of transducer elements images an object by making use of the plurality of transducer elements whose received signals are given delays, transmitting a pulse ultrasonic wave to the object and receiving its reflected wave. The transducer elements are divided into a plurality of blocks and the transducer elements in each of the blocks are selected by a selecting means so that the delays given to the received signals for the transducer elements in each of the blocks are identical.

1 . An ultrasound imaging apparatus comprising,
 a two-dimensional ultrasound transducer array which consists of a plurality of transducer elements distributed two-dimensionally and transmits a pulse ultrasonic wave to an object, each of the transducer elements receives a reflected wave of the pulse ultrasonic wave, the received signal being given a delay corresponding to an elapsed time from a transmit time when the pulse ultrasonic wave is transmitted to a receive time when each of the transducer elements receives the reflected wave of the pulse ultrasonic wave for the object to be imaged, and   a selecting means for selecting the transducer elements,   wherein the transducer elements are divided into a plurality of blocks and the transducer elements in each of the blocks are selected by the selecting means so that the delays given to the received signals for the transducer elements in each of the blocks are identical.   
   
   
       2 . The ultrasound imaging apparatus according to  claim 1 ,
 wherein a plurality of beams o be arranged at different positions on a focal plane are formed within a time of the delay, and   wherein the selecting means is a multiplexer switch that connects mutually the transducer elements in an identical phase area with respect to forming a focal point at the center position of the plurality of beams.   
   
   
       3 . The ultrasound imaging apparatus according to  claim 2 ,
 wherein a boundary between the blocks is a divisional line corresponding to a reciprocal lattice for the different positions.   
   
   
       4 . The ultrasound imaging apparatus according to  claim 2 ,
 wherein an aperture of the two-dimensional ultrasound transducer array is shaped in a rectangle, and the boundaries of the blocks are parallel to sides or diagonals of the rectangle.   
   
   
       5 . The ultrasound imaging apparatus according to  claim 4 ,
 wherein the boundaries of the blocks divide the rectangle equally into four rows and four columns parallel to sides of the rectangle, and a number of the beams formed is four.   
   
   
       6 . The ultrasound imaging apparatus according to any of  claims 1  to  4 ,
 wherein the two-dimensional ultrasound transducer array is divided into n number of blocks of M1, M2, . . . , or Mn transducer elements, each block having Nn, less than Mn, leading lines, and the selecting means comprises Mn multiplexer switches having one input and Nn outputs, respectively connected to the transducer elements of an n-th block of the blocks, where n, M, N are natural numbers.   
   
   
       7 . An ultrasound imaging apparatus comprising a two-dimensional array which consists of a plurality of transducer elements distributed two-dimensionally and transmits and receives ultrasonic waves while scanning an area to be imaged to create an ultrasound three-dimensional image,
 wherein the transducer elements are divided into a plurality of element blocks including a first element block of which a size in a second direction of an arrangement surface of the two-dimensional array is larger than a size in a first direction of the surface, and a second element block of which a size in the first direction is larger than a size in the second direction, and each of the element blocks is divided into a predetermined number of groups so as to form a transmit beam and a plurality of receive beams in the area to be imaged, the ultrasound imaging apparatus further comprising a selecting means for making transmit/receive channels of the transducer elements grouped to be one channel in each of the groups.   
   
   
       8 . An ultrasound imaging apparatus comprising a two-dimensional array which consists of a plurality of transducer elements distributed two-dimensionally and transmits and receives ultrasonic waves while scanning an area to be imaged to create an ultrasound three-dimensional image,
 wherein the transducer elements are divided into a plurality of element blocks including a differently shaped element block, and each of the element blocks is divided into a predetermined number of groups so as to form a transmit beam and a plurality of receive beams in the area to be imaged, the ultrasound imaging apparatus further comprising selecting means for making transmit/receive channels of the transducer elements grouped to be one channel in each of the groups.   
   
   
       9 . The ultrasound imaging apparatus according to  claim 7  or  8 , wherein the element blocks are rectangular. 
   
   
       10 . The ultrasound imaging apparatus according to  claim 7 , wherein the element blocks are arranged symmetric with respect to the first direction and the second direction. 
   
   
       11 . The ultrasound imaging apparatus according to  claim 7  or  8 , wherein the selecting means changes a pattern of the groups between when forming the transmit beam and when forming the receive beams. 
   
   
       12 . The ultrasound imaging apparatus according to  claim 7  or  8 , wherein the size in the first direction of the first element block is equal to or smaller than the product of the number of channels per element block and an element pitch of the two-dimensional array, and the size in the second direction of the second element block is equal to or smaller than the product of the number of channels per element block and the element pitch of the two-dimensional array. 
   
   
       13 . The ultrasound imaging apparatus according to  claim 7  or  8 , wherein the selecting means divides each of the element blocks into the predetermined number of the groups such that the integral of occurrence frequency of a delay to be given to the transducer element over a range of the delay for each of the groups is the same. 
   
   
       14 . An ultrasound imaging apparatus which has a two-dimensional array having a plurality of transducer elements arranged two-dimensionally and, by the two-dimensional array, transmits and receives ultrasonic waves scanning an area to be imaged to produce an ultrasound three-dimensional image,
 wherein the transducer elements are divided into a plurality of element blocks including an element block different in width in a elevational axis direction or a lateral axis direction of an arrangement surface of the two-dimensional array, and each of the element blocks is divided into a predetermined number of groups so as to form a transmit beam and a plurality of receive beams in the area to be imaged, the ultrasound imaging apparatus further comprising selecting means for making transmit/receive channels of the transducer elements grouped to be one channel in each of the groups.