Diagnostic ultrasound apparatus

A diagnostic ultrasound apparatus, comprising:

• an ultrasound probe for transmitting and receiving ultrasound waves to and from a patient to obtain echo data of the patient;
• a first memory means in which said echo data are to be written by being identified with addresses represented by a polar coordinate system;
• a second memory means in which said echo data read out from said first memory means are to be written according to first addresses represented by a rectangular coordinate system;
• means for sequentially generating said first rectangular coordinate addresses, said first rectangular coordinate addresses being used when said echo data are written into said second memory means;
• and
• address converting means for converting said first rectangular coordinate addresses generated by said address generating means into said polar coordinate addresses, said address conversion being carried out based upon addresses of a representative region which is one of a plurality of regions of a second rectangular coordinate system which is obtained by converting said first rectangular coordinate system so as to correspond to said polar coordinate system, in which said plurality of regions of said second rectangular coordinate system correspond to a plurality of regions of said polar coordinate system and adjacent regions have line symmetry relationship with each other, and region discriminating information which discriminates which of said plurality of regions said representative region belongs to;
• whereby said echo data are read out from said first memory means in accordance with said converted polar coordinate addresses which are supplied from said address converting means, and thus readout echo data are written into said second memory means.

A diagnostic ultrasound apparatus, comprising:

• an echo data memory in which echo data in a scanning plane obtained by performing a radial scan with an ultrasound beam are to be written by being identified with addresses S, B represented by a polar coordinate system;
• a frame memory in which said echo data which are rearranged so as to meet with a display image corresponding to said scanning plane are to be written by being identified with addresses X, Y represented by a rectangular coordinate system;
• an address generator for sequentially generating said addresses X, Y for writing said echo data into said frame memory;
• a quadrant discriminating means for discriminating a quadrant to which specified X, Y addresses belong to, said quadrant being one of a plurality of quadrants which constitute said scanning plane in which adjacent quadrants have line symmetry relationship with each other;
• a prepositioned converting means for converting said addresses X, Y into another rectangular coordinate addresses x, y which are addresses of a representative quadrant in said plurality of quadrants;
• an address conversion table for converting said address x, y of the representative quadrant into polar coordinate addresses R, .theta. of the corresponding quadrant of the polar coordinate system;
• and
• a second address converting means for converting said polar coordinate addresses R, .theta. into said polar coordinate addresses S, B based upon the discriminated quadrant information provided by said quadrant discriminating means, to output said addresses S, B to said echo data memory.

An ultrasound diagnostic apparatus, comprising:

• an ultrasound probe for radially transmitting and receiving ultrasound waves to and from a patient to form a circular scanning plane which are divided into four quadrants and obtain echo data of the patient from said scanning plane;
• a first memory means in which said echo data are to be written according to addresses represented by a polar coordinate system;
• a second memory means in which said echo data read out from said first memory means are to be written according to addresses represented by a rectangular coordinate system;
• means for generating said rectangular coordinate addresses for writing said echo data into said second memory;
• and
• means for reading out said echo data in said first memory means in a predetermined order so as to be able to produce a circular scanning image corresponding to said scanning plane on said second memory means, said reading out means including means for converting said rectangular coordinate addresses into said polar coordinate addresses, in which the corresponding relationship between the rectangular coordinate addresses and the polar coordinate addresses only for a common representative quadrant which is one of said quadrants is calculated, and the corresponding relationship between the rectangular coordinate addresses and the polar coordinate addresses for the other quadrants are obtained based upon the calculated result and line symmetry relationship between said representative quadrant and each of the other quadrants, whereby according to the generation of said rectangular coordinate addresses by said address generating means, the echo data stored in said first memory means corresponding to the generated rectangular coordinate addresses are sequentially read out from said said first memory means.