US 11,850,098 B2
Method and device for measuring an ultrasound parameter of a viscoelastic medium
Stéphane Audière, Paris (FR); and Laurent Sandrin, Bourg-la-Reine (FR)
Assigned to ECHOSENS, Paris (FR)
Filed by ECHOSENS, Paris (FR)
Filed on Jun. 14, 2019, as Appl. No. 16/441,970.
Prior Publication US 2020/0390421 A1, Dec. 17, 2020
Int. Cl. A61B 8/08 (2006.01); A61B 8/14 (2006.01)
CPC A61B 8/485 (2013.01) [A61B 8/14 (2013.01); A61B 8/5246 (2013.01)] 18 Claims
OG exemplary drawing
 
1. Method for measuring an ultrasound parameter of a viscoelastic medium to be characterized with an elastography system configured to generate a shear wave in a region of interest, the elastography system including an ultrasound transducer configured to emit a sequence of ultrasound shots and to receive corresponding echo signals from the region of interest, and a processor programmed to alternately operate at least in a first mode and a second mode, wherein in the first mode, the processor is programmed to generate a first sequence of ultrasound shots with said ultrasound transducer to measure an attenuation of ultrasound signals in a tissue; and wherein in the second mode, the processor is programmed to control the elastography system to create a shear wave in the tissue; and to generate a second sequence of ultrasound shots with said ultrasound transducer to track how the tissue in the region of interest is moved by the shear wave, the method comprising:
operating the processor in the first mode, said operating comprising
generating the first sequence of ultrasound shots with said ultrasound transducer to the region of interest and receiving corresponding first mode echo signals from the region of interest without generating the shear wave which is used to measure shear wave speed in the tissue;
recording first mode ultrasound attenuation values associated with the received first mode echo signals obtained without generating said shear wave, and
calculating a value of the ultrasound parameter using at least the first mode ultrasound attenuation values,
wherein the first sequence of ultrasound shots has a duration that is longer than the second sequence of ultrasound shots,
wherein the method further comprises processing the first mode ultrasound attenuation values using one or more quality criteria to determine, among the recorded first mode ultrasound attenuation values, ultrasound attenuation values that have a predetermined quality level, and wherein the value of the ultrasound parameter is calculated using first mode ultrasound attenuation values that have the predetermined quality level, and
wherein the one or more quality criteria include a correlation criterion and wherein the processing includes associating each one of the received first mode echo signals with a correlation coefficient and selecting each of the received first mode echo signal having the correlation coefficient past a predetermined threshold value to determine, among the received first mode echo signals, first mode echo signals that are sufficiently decorrelated.