Ultrasonic diagnostic device

1. Ultrasonic diagnostic equipment configured to automatically determine a start depth of three-dimensional picture generation and to start three-dimensional picture generation, the ultrasonic diagnostic equipment comprising:

a transmission/reception controller configured to control transmitting and receiving an ultrasonic signal through an ultrasonic probe;

a divider configured to cumulate brightness values in a depth direction of an ultrasonic received signal based on the ultrasonic signal to thereby divide the depth direction of said ultrasonic received signal into a plurality of depth zones such that respective cumulative addition brightness values, respectively associated with respective depth zones, are approximately equal to a predetermined value, each depth zone of the plurality of depth zone having a zone length, along the depth direction, corresponding to a number of brightness values, which are accumulated by the divider to establish the depth zone;

a start depth determiner configured to:

select a user-configurable number of three-dimensional picture generation start candidate zones having the longest zone lengths among the plurality of depth zones,

select a three-dimensional picture generation start candidate, from the user-configurable number of three-dimensional picture generation start candidate zones, having a shallowest depth along the depth direction of the received ultrasound signal, as a three-dimensional picture generation start zone, and

determine a predetermined depth inside said three-dimensional picture generation start zone as the start depth of said three-dimensional picture generation; and

a three-dimensional picture generator configured to start three-dimensional picture generation from the start depth of said three-dimensional picture generation start zone determined by said start depth determiner and to generate a three-dimensional picture of said ultrasonic received signal.

2. The ultrasonic diagnostic equipment according to claim 1 , wherein said divider is configured to obtain a voxel data column targeted for a ray-casting calculation from three-dimensional volume data generated from said ultrasonic received signal and to repeat a process in which the divider for dividing the voxel data column into the plurality of depth zones:

scans the voxel data column from a beginning point of the voxel data column while carrying out a cumulative addition of a product of voxel data of a voxel and a predetermined accumulation coefficient; and

records a depth in the voxel data column when a cumulative addition value exceeds a predetermined threshold to generate a depth zone at the recorded depth and re-initializes the cumulative addition value,

until a voxel data column end point is reached.

3. The ultrasonic diagnostic equipment according to claim 2 , wherein the three-dimensional picture generator configured to carry out the ray-casting calculation to generate the three-dimensional picture of said ultrasonic received signal.

4. The ultrasonic diagnostic equipment according to claim 1 , wherein said start depth determiner is further configured to:

sort the user-configurable number of depth zones in a decreasing order according to zone length to identify a top N (N is the integer of 1 or more) three-dimensional picture generation start candidate zones or ray-casting start candidate zones in the order,

define, when there is a three-dimensional picture generation start candidate zone or ray-casting start candidate zone smaller than a preset zone length in the top N three-dimensional picture generation start candidate zones or ray-casting start candidate zones, a preset position inside a zone having the shallowest depth among the three-dimensional picture generation start candidate zones or ray-casting start candidate zones as the three-dimensional picture generation start depth or ray-casting start depth, and

determine, when all of said top N three-dimensional picture generation start candidate zones or ray-casting start candidate zones have the preset zone length or less, a lead position of the voxel data column targeted for three-dimensional picture generation or ray-casting calculation as the three-dimensional picture generation start position or ray-casting start position.

5. The ultrasonic diagnostic equipment according to claim 1 , further comprising:

a candidate zone number setter configured to enable a user to set the user-configurable number of said three-dimensional picture generation start candidate zones for said start depth determiner; and

a superimposing unit configured to superimpose a depth color classification picture of the start depth of said three-dimensional picture generation, which is determined by said start depth determiner in accordance with the user-configurable number of said three-dimensional picture generation start candidate zones set by said candidate zone number setter, on the three-dimensional picture generated by said three-dimensional picture generator.

6. The ultrasonic diagnostic equipment according to claim 1 , wherein the respective cumulative addition brightness values, respectively associated with respective depth zones and having approximately equal values, are computed by initializing a cumulative addition brightness value to zero at a start point and recording a depth in the received ultrasonic signal when the cumulative addition brightness value, from the start point, exceeds the predetermined value.