The Conical Scanner: A Two Transducer Ultrasound Scatter Imaging Technique

A new two transducer ultrasound scatter imaging system has been developed. In operation, a large conical transducer generates an ultrasound beam that converges to a sharp line focus in the tissue being imaged. The second transducer is aimed along the axis of the cone and detects scattered ultrasound as a function of time, converting this information into a high resolution image. Excellent focusing properties are maintained over a large depth of field with no increase in the complexity of standard B-scanner electronics. As well, no increase in time is required to generate the image. The performance of a 45° conical scanner is examined theoretically and experimentally. The FWHM of the lateral point response of the scanner remains 0.25 mm over a 5 cm depth of field. Images of phantoms and in vitro breast tissue demonstrate a great improvement in image quality compared with conventional pulse-echo imaging.

[1]  J. Plummer,et al.  Monolithic Silicon-PVF2 Piezoelectric Arrays for Ultrasonic Imaging , 1980 .

[2]  N. Murayama,et al.  The strong piezoelectricity in polyvinylidene fluroide (PVDF) , 1976 .

[3]  C. Burckhardt.  Speckle in ultrasound B-mode scans , 1978, IEEE Transactions on Sonics and Ultrasonics.

[4]  F. Foster,et al.  Cylindrical transducer scatter scanner , 1980 .

[5]  Albert Freedman,et al.  Sound Field of Plane or Gently Curved Pulsed Radiators , 1970 .

[6]  C. R. Hill,et al.  Acoustic Bragg diffraction from human tissues , 1975, Nature.

[7]  H. Ohigashi,et al.  Electromechanical properties of polarized polyvinylidene fluoride films as studied by the piezoelectric resonance method , 1976 .

[8]  Mauri Luukkala,et al.  The impulse response and pressure nearfield of a curved ultrasonic radiator , 1976 .

[9]  M Arditi,et al.  Transient fields of concave annular arrays. , 1981, Ultrasonic imaging.

[10]  G. T. Davis,et al.  Plasma poling of poly(vinylidene fluoride): Piezo‐ and pyroelectric response , 1980 .

[11]  F. L. Thurstone,et al.  Acoustic Speckle: Theory and Experimental Analysis , 1979 .

[12]  A. J. Hayman,et al.  Observations of the propagation of very short ultrasonic pulses and their reflection by small targets , 1978 .

[13]  L. Bess,et al.  Near field transient radiation patterns for circular pistons , 1974 .

[14]  P. Stepanishen.  Transient Radiation from Pistons in an Infinite Planar Baffle , 1970 .

[15]  P.-A. Grandchamp,et al.  Focussing Ultrasound Over a Large Depth with an Annular Transducer-An Alternative Method , 1975, IEEE Transactions on Sonics and Ultrasonics.

[16]  David Vilkomerson,et al.  Progress in Annular-Array Imaging , 1975 .

[17]  Robert C. Waag,et al.  Angle Scan and Frequency-Swept Ultrasonic Scattering Characterization of Tissue , 1978 .

[18]  Heinz Hoffmann,et al.  Ultrasound Axicon: a device for focusing over a large depth , 1973 .

[19]  J. Mcleod.  The Axicon: A New Type of Optical Element , 1954 .