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TOPIC:ADVANCES IN ULTRASOUNDS (US)
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TOPIC:ADVANCES IN ULTRASOUNDS
10/5/2021 8:00:44 AM
0. CONTENTS
1.
GENERAL INTRODUCTION
2.
TRANSDUCERS.
3.
US IMAGING MODES AND NEW IMAGING MODES
4.
5. ADVANCES IN US-THERAPY
1.
A, B, M-MODES
1.
HIGH INTENSITY FOCUSED US.
2.
NEW MODES
2.
US DRUG AND GENE DERIVERY
ADVANCES IN US- DIAGNOSIS
1.
Diagnosis Contrast agents
2.
Elastography
3.
Tissue harmonic imaging
4.
Vibro acoustography and acoustic microscopy
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6. CONCLUSION
7. REFERENCING
TOPIC:ADVANCES IN ULTRASOUNDS
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1. GENERAL INTRODUCTION
ULTRASOUND IMAGING ADVANTAGES:
a.
Non ionic modality in nature therefore safe
for prenatal imaging
b.
Easy to use i.e. some machines are portable
c.
Non invasive
d.
Capture live (real time ) image of soft tissues.
GAP over years: Small bandwidth, contrast and spatial
resolution.
Objective: Use of technological advances in electronics and
computational to expand applications.
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TOPIC:ADVANCES IN ULTRASOUNDS
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2. US TRANSDUCERS
1.
Protective layer for protection
2.
Lens for beam focusing
3.
Matching layer: For US energy transfer from transducer to the
medium.
4.
Piezoelectric element: For electrical to sound energy and vice versa.
5.
Backing block for damping resonant vibrations.
Note: 1. Reverberation artifacts may be reduced by shifting from Lead zirconate titanate to ferroelectric
relaxors PZT.
2. Advances in US have also to keep on improving beam focusing and steering by changing array
configurations, digital image processing technology , hanafy lens as well as extending field of view.
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TOPIC:ADVANCES IN ULTRASOUNDS
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3. ULTRASOUND IMAGING MODES
2) Different techniques such Doppler imaging, non linear imaging, harmonic
imaging, extended field of view, 3D US have been manufactured to advances
US. In addition the processing modes such as automatic gain compensation
and photopic US real time post processing modes are advancing the
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AMUS.
applications
TOPIC:ADVANCES IN ULTRASOUNDS
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4. ADVANCES IN US_DIAGNOSIS
1. Diagnosis Contrast agents
 US lacked the contrast agents as it was for other modalities.
 Form 1990s where microbubbles (<10 micrometers diameter) have started to be used by enhancing the
echogenicity.
 Microbubbles consist of gas such as air or perfluorocarbon and they can be stabilized by shell
phospholipid.
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TOPIC:ADVANCES IN ULTRASOUNDS
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4. ADVANCES IN US_DIAGNOSIS
2. Elastography
Young's modulus E: The longitudinal elasticity or
stiffness of a tissue, ΔL/L (the percentage change in
its length) in response to stress σ which equals the
action of a contraction force F on the tissue’s
surface A.
E = (stress)/(strain)=
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𝐹
𝐴
∆𝐿
𝐿
TOPIC:ADVANCES IN ULTRASOUNDS
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4. ADVANCES IN US_DIAGNOSIS
3.
Tissue harmonic imaging
Is a grayscale ultrasound mode that
provides images of higher quality than
conventional sonography.
Is based on the phenomenon of
nonlinear distortion of acoustic signal
as it travels through the body.
Harmonics are produced by tissue vibration
and are usually integral multiples of the
transmitted frequency
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3.
Tissue harmonic imaging
Harmonic wave frequencies are higher
integer multiples of the transmitted
frequency.
Current technology uses only the second
harmonic(twice the transmitted
frequency) for imaging.
The processed image is formed with use of the
harmonic frequency bandwidth in the received
signal after the transmitted frequency spectrum
is filtered out
TOPIC:ADVANCES IN ULTRASOUNDS
10/5/2021 8:00:44 AM
4. ADVANCES IN US_DIAGNOSIS
4. A. Vibro acoustography
 The image is built up through interference of
two scanning the focused beam across the
object of interest.
4. B. acoustic microscopy
 This uses a ultra high frequency (30- 100 MHz)
micro transducer composed of polymer ferroelectric
polyvinylidene fluoride to increase bandwidth. This
allows its usage in ophthalmology diseases.
The technique uses attenuation and impedance to
produce images.
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TOPIC:ADVANCES IN ULTRASOUNDS
10/5/2021 8:00:44 AM
5. ADVANCES IN US_THERAPY
1.
HIGH INTENSITY FOCUSED ULTRASOUND(HIFU)
HIFU is a therapy that uses focused ultrasound waves to thermally
remove a portion of tissue.
 As people age, collagen decreases therefore HIFU treatment may
be used for collagen production.
HIFU is used to destroy a defined volume of tissue by inducing a
rise in temperature greater than 500 𝐶
Example: Treatment of liver, prostate and kidney tumors.
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TOPIC:ADVANCES IN ULTRASOUNDS
10/5/2021 8:00:44 AM
5. ADVANCES IN US_THERAPY
2. US DRUG AND GENE DERIVERY
 Not all drug particles are allowed to get into cell during current drug and gene delivery
 A low frequency US waves may be focused on the target to make a small and temporary opening for
injected particles to be penetrated (sonoporation) into the cytoplasm up to nucleus of the cell for gene
derivery.
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TOPIC:ADVANCES IN ULTRASOUNDS
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6. CONCLUSION
The modern technological advances in electronics and
computing is bring divers imaging modes.
Advances in ultrasounds is progressing to give diagnosis and
therapeutic choices.
Contrast agents have been used to improve contrast in clinic
applications
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REFERENCING
1. Christopher J. H, James M.P, Robert J.E, Martin J.K.B, & David O.C ( 2001). Advances in ultrasound. Clinical Radiology 57, 157-177.
2. Andrzej N. , & Katarzyna D. Introduction to ultrasound elastography. J Ultrason. 2016 Jun; 16(65): 113–124.
3.
Porter,T., Zeng, P. & Xie, F. Advances in Ultrasound Therapeutics. Curr Cardiol Rep 23, 133 (2021).
4. Dr.Yunjie Tong. Medical Imaging Systems: Ultrasound( lecture slides). UR& Perdue University(2021).
+Questions / Supporting Ideas
Thank You Very Much.
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