Localizing Medical Instruments Using Doppler Ultrasound Twinkling Artifact Signatures

Abstract

Markers, medical instruments, and/or medical devices have a composition and/or other features or characteristics such that they will generate twinkling artifacts when imaged with ultrasound. In this way, the markers, medical instruments, and/or medical devices can be detected and localized using ultrasound. Ultrasound technical specifications that are optimized to generate twinkling artifact signatures are selected and used to facilitate localization of such markers, instruments, and/or devices.

1 . A method for localizing an ultrasound-detectable marker, the method comprising:
 (a) operating an ultrasound system to select imaging parameters, wherein the imaging parameters are selected to optimize generating a twinkling artifact signature;   (b) obtaining Doppler ultrasound data using the ultrasound system operating with the selected imaging parameters, wherein the Doppler ultrasound. data are obtained from a region-of-interest (ROI) containing a marker that when insonated with ultrasound generates a twinkling artifact signature; and   (c) localizing the marker in the ROI based on the twinkling artifact signature.   
     
     
         2 . The method of  claim 1 , wherein the imaging parameters comprise at least one of color ultrasound transmit frequency, color gain, color scale, threshold, and wall filter. 
     
     
         3 . The method of  claim 2 , wherein the ultrasound system includes a broad-spectrum linear transducer. 
     
     
         4 . The method of  claim 3 , wherein the imaging parameters comprise:
 a color scale setting selected from a range of ±2 cm/s to ±12 cm/s;   a color ultrasound transmit frequency setting selected from a range of 3.1 MHz to 6.3 MHz; and   a color gain setting selected from a range of 18 dB to 25 dB.   
     
     
         5 . The method of  claim 4 , wherein the color scale setting is selected from a range of ±3 cm/s to ±6 cm/s. 
     
     
         6 . The method of  claim 4 , wherein the color gain setting is selected from a range of 19.5 dB to 23.5 dB. 
     
     
         7 . The method of  claim 3 , wherein the imaging parameters comprise:
 a color scale setting selected from a range of ±2 cm/s to ±12 cm/s;   a color ultrasound transmit frequency setting selected from a range of 3.1 MHz to 6.3 MHz; and   a color gain setting selected from a range of 40% to 60%.   
     
     
         8 . The method of  claim 2 , wherein the ultrasound system includes a broad-spectrum linear matrix-array transducer. 
     
     
         9 . The method of  claim 8 , wherein the imaging parameters comprise:
 a color scale setting selected from a range of ±3 cm/s to ±9 cm/s;   a color ultrasound transmit frequency setting selected from a range of 5.0 MHz to 12.5 MHz; and   a color gain setting selected from a range of 18 dB to 25 dB.   
     
     
         10 . The method of  claim 9 , wherein the color scale setting is selected from a range of ±5 cm/s to ±7 cm/s. 
     
     
         11 . The method of  claim 9 , wherein the color ultrasound transmit frequency setting is selected from a range of 6 MHz to 7 MHz. 
     
     
         12 . The method of  claim 9 , wherein the color gain setting is selected from a range of 20.5 dB to 23.5 dB. 
     
     
         13 . The method of  claim 8 , wherein the imaging parameters comprise:
 a color scale setting selected from a range of ±3 cm/s to ±9 cm/s;   a color ultrasound transmit frequency setting selected from a range of 5.0 MHz to 12.5 MHz; and   a color gain setting selected from a range of 40% to 70%.   
     
     
         14 . The method of  claim 2 , wherein the ultrasound system includes a curvilinear array transducer. 
     
     
         15 . The method of  claim 14 , wherein the imaging parameters comprise:
 a color scale setting selected from a range of ±4 cm/s to ±20 cm/s;   a color ultrasound transmit frequency setting selected from a range of 2 MHz to 4 MHz; and   a color gain setting selected from a range of 14 dB to 25 dB.   
     
     
         16 . The method of  claim 15 , wherein the color scale setting is selected from a range of ±6 cm/s to ±18 cm/s. 
     
     
         17 . The method of  claim 15 , wherein the color ultrasound transmit frequency setting is selected from a range of 2.1 MHz to 3.6 MHz. 
     
     
         18 . The method of  claim 15 , wherein the color gain setting is selected from a range of 14 dB to 23 dB. 
     
     
         19 . The method of  claim 14 , wherein the imaging parameters comprise:
 a color scale setting selected from a range of ±4 cm/s to ±20 cm/s;   a color ultrasound transmit frequency setting selected from a range of 2 MHz to 4 MHz; and   a color gain setting selected from a range of 40% to 70%.   
     
     
         20 . The method of  claim 1 , wherein the imaging parameters comprise pulse repetition frequency and at least one of color scale and color ultrasound transmit frequency, and wherein the pulse repetition frequency is modulated by the at least one of color scale and color ultrasound transmit frequency. 
     
     
         21 . The method of  claim 1 , wherein the imaging parameter comprise at least one of focal zone, field-of-view, and color flow region-of-interest. 
     
     
         22 . The method of  claim 21 , wherein the focal zone is selected to be within a threshold distance from the marker in the ROI. 
     
     
         23 . The method of  claim 22 , wherein the threshold distance is 1 centimeter. 
     
     
         24 . The method of  claim 22 , wherein the threshold distance is selected to be a distance posterior to the marker in the ROI. 
     
     
         25 . The method of  claim 21 , wherein the color flow region-of-interest is selected to have a width equal to one-half of a width of an imaging region. 
     
     
         26 . The method of  claim 1 , further comprising repeating steps (a) and (b) while varying at least one of the selected imaging parameters and analyzing the Doppler ultrasound data to identify a presence of the twinkling artifact signature in order to select the imaging parameters that optimize the twinkling artifact signature. 
     
     
         27 . The method of  claim 1 , wherein localizing the marker in the ROI comprises computing a spatiotemporal variation of the twinkling artifact signature in the Doppler ultrasound data and localizing the marker in the ROI based on the spatiotemporal variation of the twinkling artifact signature. 
     
     
         28 . The method of  claim 27 , further comprising generating an auditory output to a user based on localizing the marker. 
     
     
         29 . The method of  claim 27 , further comprising generating a haptic feedback signal for a user based on localizing the marker. 
     
     
         30 . The method of  claim 1 , wherein the marker comprises a metallic biopsy clip that when insonated generates the twinkling artifact signature. 
     
     
         31 . The method of  claim 30 , wherein the metallic biopsy clip is coated in a non-metallic material. 
     
     
         32 . The method of  claim 30 , wherein at least part of a surface of the metallic biopsy clip is textured to generate the twinkling artifact signature when insonated. 
     
     
         33 . The method of  claim 1 , wherein the marker is coupled to a medical instrument and localizing the marker in the ROI comprises localizing the medical instrument. 
     
     
         34 . The method of  claim 33 , wherein the marker is a coating applied to a surface of the medical instrument. 
     
     
         35 . The method of  claim 33 , wherein the medical instrument comprises at least one of a clip, a wire, a needle, a brachytherapy needle, a tube, a drain, a catheter, an endoscopic capsule, a cardiac pacer lead, an implant, a suture, and a prosthetic valve. 
     
     
         36 . The method of  claim 1 , wherein the marker comprises a portion of a medical instrument that has been textured to generate the twinkling artifact signature and localizing the marker in the ROI comprises localizing the medical instrument. 
     
     
         37 . The method of  claim 36 , wherein the medical instrument comprises at least one of a clip, a wire, a needle, a brachytherapy needle, a tube, a drain, a catheter, an endoscopic capsule, a cardiac pacer lead, an implant, a suture, and a prosthetic valve. 
     
     
         38 . The method of  claim 1 , wherein the ultrasound system includes a curvilinear array transducer and the marker is at least one of coupled to a medical instrument or a portion of a medical instrument that has been textured to generate the twinkling artifact signature. 
     
     
         39 . The method of  claim 38 , wherein the medical instrument is a brachytherapy needle. 
     
     
         40 . The method of  claim 1 , wherein the Doppler ultrasound data comprise non-gated acoustic signal data.