Automated identification of the location of a regurgitant orifice of a mitral valve in an ultrasound image
An ultrasonic diagnostic imaging system is described which quantifies regurgitant flow through a mitral valve, including the automatic indication of the location of a regurgitant orifice in an ultrasound image. A clinician images the regurgitant valve and indicates in the image the presumed location of the regurgitant orifice ( 130 ). A flow quantification processor is responsive to this initial location estimate by the clinician to calculate a refined estimation of the orifice location. The refined location is indicated on the ultrasound image by the imaging system, either by relocating an icon placed by the clinician, or displaying a second icon ( 132 ) on the image at the refined location.
1. A diagnostic ultrasound system for assessing regurgitant flow, the diagnostic ultrasound system comprising:
a display;
a transducer array; and
a processor configured to cause the ultrasound system to perform the following steps:
control the transducer array operatively coupled to the diagnostic ultrasound system to transmit ultrasonic energy to and receive ultrasonic echoes from a location of regurgitant flow passing through a tissue boundary in a body;
produce an ultrasound image of the location of regurgitant flow;
produce, based on the received echoes, Doppler ultrasound measurements of blood flow velocity in a flow velocity field in a vicinity of the location of regurgitant flow;
based on an initial estimation of a location of an orifice and the blood flow velocity measurements in the vicinity of the location of the regurgitant flow, refine calculated location coordinates of each pinhole regurgitant orifice of a plurality of pinhole regurgitant orifices by iteratively adjusting one or more parameters of a flow velocity field model in response to the blood flow velocity measurements, wherein the blood flow velocity measurements originate from a plurality of overlapping zones spatially distributed along the tissue boundary in the body and wherein the blood flow velocity measurements correspond to the plurality of pinhole regurgitant orifices, wherein the processor is further configured to refine the calculated location coordinates of the orifice by reducing an integrated error term between estimated velocity values and the blood flow velocity measurements until the integrated error term is minimized, wherein the integrated error term comprises a mean squared error term for the flow velocity field generated by integrating error terms between the estimated velocity values and the corresponding blood flow velocity measurements at each measured point within the flow velocity field; and
display on the display an indication of a location of a regurgitant orifice in an ultrasound image based on the calculated location coordinates.
2. The diagnostic ultrasound system of claim 1 , wherein the processor is further configured to, based on an input from a user control operable by a user, indicate a location of an orifice in the ultrasound image.
3. The diagnostic ultrasound system of claim 2 , wherein the processor is further configured to, based on the input from the user control, produce calculated coordinates of the orifice.
4. The diagnostic ultrasound system of claim 2 , wherein the processor is further configured to, based on the input from the user control, display an orifice icon at the indicated location of the orifice in the ultrasound image.
5. The diagnostic ultrasound system of claim 4 , wherein the processor is further configured to, based on calculated location coordinates relocate the displayed orifice icon to the calculated location coordinates.
6. The diagnostic ultrasound system of claim 4 , wherein the processor is further configured to, based on calculated location coordinates, display a second orifice icon in the ultrasound image at the calculated location coordinates.
7. The diagnostic ultrasound system of claim 1 , wherein the processor is further configured to adjust the calculated location coordinates of the orifice in relation to a distance of the orifice from a mitral valve plane as the integrated error term is reduced.
8. The diagnostic ultrasound system of claim 1 , wherein the processor is further configured to produce a measure of flow rate through the orifice.
9. The diagnostic ultrasound system of claim 1 , wherein the processor is further configured to produce a measure of the volume flow through the orifice.
10. The diagnostic ultrasound system of claim 1 , wherein the processor is further configured to produce the calculated location of the orifice in Cartesian coordinates.
11. The diagnostic ultrasound system of claim 1 , wherein the processor is further configured to produce the calculated location of the orifice in spherical coordinates.