ultrasound basics - conquest imaging...ultrasound transducers used in diagnostic imaging employ an...

Ultrasound Basics

Presented by: Matt [email protected] Imagingwww.conquestimaging.com

© 2016 Conquest Imaging

http://www.conquestimaging.com

Agenda

Introduction and Welcome

Ultrasound Basics

Ultrasound Types

Building Blocks of a Diagnostic Ultrasound System


Welcome to Ultrasound Basics training presented by Conquest Imaging. After completing this training you will:

Understand the basic principles of diagnostic ultrasound.

Be able to identify transducer types and their use.

Understand the trade-offs with regard to image quality and resolution.

Understand the different imaging modes.

Be familiar with the basic building blocks of any ultrasound system.

Be familiar with different systems and their intended use.

Introduction and Welcome



Introduction to Ultrasound

This module provides a basic review of ultrasound theory topics. After completing this module you will be familiar with the basic concepts needed to understand how ultrasound works.

What is Ultrasound?

Sound Types by Frequency Range

What is the Piezoelectric Effect?

Ultrasound Transducers

Tissue Interactions

Image Quality


What is Ultrasound?

It’s a sound wave with frequency higher than 20,000 Hz.


What is Ultrasound?

Humans can hear sound in the frequency range between 20 to 20,000 Hz or 20 KHz.

Sound is a mechanical, longitudinal pressure wave that travels through a medium such as air, water or metal.

What is the average speed of ultrasound waves in human tissue? 1540 m/s

What is the average speed of ultrasound waves in outer space?

Outer space has no medium for sound to travel through; it is a vacuum therefore: 0 m/s


Frequency Range (Hertz)

Designation Examples

0-16 Hz Infrasound Seismic waves

16Hz-20KHz Audible Sound Speech, music

20KHz-10GHz Ultrasound Dolphins, medicine

1MHz-20MHz Medical Ultrasound Ultrasound Imaging

!0GHz-10TH Hyper sound Acoustic Microscopy

500 Hz 1000 Hz

20000 Hz

22000 Hz

Sound Types by Frequency Range


Ultrasound Applications

Clinical Application Imaging Modes Used For:

Radiology 2D Gall bladder, kidney, liver, spleenbreast and thyroid

Cardiology 2D, CW, AUX CW, PW Doppler and Color Doppler

Noninvasive evaluation of heart function

Vascular 2D, Color Doppler and PW Doppler Detection of blood flow and evaluation of any abnormalities

OB/GYN 2D, M, PW Doppler, and Color Doppler

Viewing fetal structures such as heart, kidneys and maternal structures such as ovaries, fallopian tubes and uterus


By using piezoelectric elements that generate an ultrasound wave in response to an electrical pulse.

The ultrasound wave then travels through a medium such as the human body.

Some of its energy gets reflected back toward the source.

How Do We Generate an Ultrasound Wave?


Piezoelectricity is the ability of certain materials to generate an electric potential in response to applied mechanical stress.

The word is derived from the Greek piezo or piezein, which means to squeeze or press.

The Curie brothers discovered piezoelectricity on quartz crystals. This material is still in use today for precise timing and resonator applications. Quartz is a naturally occurring single-crystal material.

In 1954 the discovery of Lead Zirconate Titanate (PZT) ceramics led to a family of synthetic materials suitable for many applications. These materials are the most popular choice for ultrasound imaging transducers and arrays.



The most important property of a piezoelectric material is how it can convert electric energy to acoustic energy and vice versa.



Ultrasound transducers used in diagnostic imaging employ an array of piezoelectric elements.

Each element is wired to allow the application of short high voltage pulses during the transmission of ultrasound waves and the reception of the electronic signal generated during the receive phase.

The average 2D transducer utilizes 128 piezoelectric elements.

Diagnostic ultrasound imaging range of frequencies is between 1 to 20 MHz.



The higher the frequency of the ultrasound wave, the less it can penetrate, and the lower the frequency, the deeper it can penetrate.

The higher the frequency, the higher the axial resolution resulting in better image quality.

The lower the frequency, the lower the axial resolution resulting in lower image quality.


Probe

Axial

Lateral


Phased

Array

Linear

Array

Curved

Linear

Array

Standard Array Formats


Linear Probe Piezoelectric Linear Array

Linear Ultrasound Transducer


Phased Array Probe

Piezoelectric Phased Array

Phased Array Ultrasound Transducer


An ultrasound beam requires focusing during transmit to improve the resolution of the acquired image.

Transmit focus is done electronically in all modern ultrasound systems.

Ultrasound Beam Focusing


The timing of the transmit pulses to each element is aligned so that the wave fronts from all the piezoelectric elements arrive at a selected spatial point at the same time.

This is accomplished by introducing a curve into the timing delays, whose center is the desired focal point.

Electronic focus is the same as using an acoustic lens; however, using electronic instead of physical focus allows the transmit focal point to be changed simply by changing the delay pattern.

Ultrasound Beam Focusing


The wave fronts propagate once they leave the transducer, and there is no way to alter the transmit energy pattern.

During the receive mode, dramatic enhancement of the focal capabilities of the system can be achieved.

As the ultrasound wave strikes various interfaces/tissues in the body, some of its energy is transmitted and some is reflected toward the transducer.

Ultrasound Receive Focusing

Reflected Energy

Transducer


During the receive phase, an electronic lens is continuously reshaped as the focal point moves away from the array at half the velocity of ultrasound to maintain precise focus along each scan line.

“Receive Dynamic Focus” maintains superior resolution throughout the ultrasound image, and the resolution is not limited by a small transducer aperture (number of active elements used to generate one scan line) or by a fixed focal zone.

Receive Dynamic Focus

Dynamic focus is achieved by controlling the delay of each signal arriving at each element through each channel, such that only signals from the computed sliding focal point arrive at a final summation point at the same time.


Dynamic focus is achieved by controlling the delay of each signal arriving at each element through each channel, such that only signals from the computed sliding focal point arrive at a final summation point at the same time.

Receive Dynamic Focus


The ultrasound system applies high voltage pulses to the transducer elements. This produces ultrasound waves that travel through the human body and interact with various organs.

The reflected energy travels back to the transducer where each of its elements acts as a receiver. The reflected ultrasound energy is converted into tiny electrical signals.

The ultrasound system processes these signals to produce an image that represents these reflections on the monitor.

Gray-scale Imaging / 2D Imaging Dynamic Focus


When an ultrasound wave travels through a medium, it causes expansion and compression of the medium.

Ultrasound waves interact with tissue in these five basic manners:

Transmission

Reflection

Scattering

Attenuation

Refraction

Tissue Interactions


Transmission: Sound energy transmitted from the transducer enters the body.

Some of the ultrasound energy continues deeper into the body.

These waves will reflect from deeper tissue structures.

Tissue Interactions

Transducer


Reflection: This is the source for the ultrasound image.

Some waves reflect off different tissues and return back to the ultrasound transducer.

Tissue Interactions

Transducer


Scattering:

The signal that reaches the transducer is a much weaker than the transmitted one and is typically 100-1000 (40 - 60 dB) less than the transmitted signal.

Most scattering occurs with red blood cells, which have a width of 7-10 µm, which is 20 times smaller than the ultrasound wavelength (0.2 to 1 mm).

Tissue Interactions


Attenuation: is the decreasing intensity of a sound wave as it passes through a medium. It is the result of energy absorption of tissue, as well as reflection and scattering that occurs between the boundaries of tissue with different densities.

Tissue absorption of sound energy contributes most to the attenuation of an ultrasound wave in tissues.

The deeper the ultrasound wave travels in the body, the weaker it becomes.

Deep reflections require extra amplification when used to build an ultrasound image.

Tissue Interactions


The American Institute of Ultrasound in Medicine (AIUM) guidelines for limits below which ultrasound clearly has been demonstrated to be safe:

A diagnostic exposure that produces a 1°C or less temperature elevation above normal.

An exposure intensity less than 1 W/cm2 for focused ultrasound beams.

Diagnostic ultrasound systems generally have outputs ranging from 10 mW/cm2 for imaging to as high as 430 mW/cm2 for pulsed Doppler ultrasound. There has been no evidence to date to suggest adverse effects at these ultrasonic outputs.

Ultrasound Attenuation Effects

Ultrasound attenuation by tissue produces heat energy and this property is used for some non-diagnostic treatments.

Extreme prolonged exposure without movement of the transducer could cause harm to tissues.


Refraction: takes place at an interface due to the different velocities of the acoustic waves within the two materials. Occurs when the ultrasound signal is deflected from its straight path and the angle of deflection is away from the transducer.

Refraction


Refraction: Ultrasound waves are only refracted at a different medium interface of different acoustic impedance.

Refraction

Refraction allows enhanced image quality by using acoustic lenses.

Refraction can result in ultrasound double-image artifacts.


Image Quality

The following parameters influence ultrasound image quality:

Detail/Spatial Resolution: The ability to distinguish small structures (axial and lateral resolution).

Image Uniformity: Comparable detail and contrast throughout the image.

Contrast resolution: The ability to differentiate different tissue types without introducing noise.

Temporal Resolution/Frame rate: The rate to acquire frames and display them.

Dynamic range: Largest and smallest signals acquired and displayed.

Spatial Discrimination: The ability to limit artifacts and reflections from other locations.

Bandwidth: The system ability to reproduce signals appropriately.


Image Resolution

Axial Resolution:

Axial resolution is the minimum separation between two structures the ultrasound beam can distinguish parallel to the beam path.

Axial Resolution

The ability to separate structures parallel to the ultrasound beam


Image Resolution

Would be seen as one structure

Would be seen as two structures


LateralResolution

Linear Array

Lateral Resolution: Lateral Resolution is the minimum separation from other tissue the ultrasoundbeam can distinguish in a plane perpendicular to the ultrasound beam.


Image Resolution

Would be seen as two structures


Linear Array

Transverse Resolution

Transverse Resolution: Transverse Resolution is the ability to differentiate structures side by side within the ultrasound beam across the image plane.


Image Resolution

Linear Array

Contrast Resolution: The ability to differentiate different tissue types without introducing noise. The use of a tissue mimicking phantom allows the user to qualify the contrast resolution of the ultrasound system. The system should be able to resolve structures with contrast level differences as low as 3 dB.


Image Resolution

Contrast Resolution:


Ultrasound Modes

This module provides an overview of ultrasound modes. After completing this module you will be familiar with the different modes of ultrasound and their appropriate uses.

Doppler Ultrasound

Pulsed Wave Doppler (PW)

AUX Continuous Wave Doppler (CW)


Doppler Ultrasound

What is the Doppler Effect?

A change in the observed frequency of a wave, as of sound or light, occurring when the source and observer are in motion relative to each other, with the frequency increasing when the source and observer approach each other and decreasing when they move apart. Also called Doppler Shift.

http://upload.wikimedia.org/wikipedia/commons/9/9e/Doppler_effect.svg

http://upload.wikimedia.org/wikipedia/commons/9/9e/Doppler_effect.svg


Doppler Ultrasound

If the source is moving toward the receiver, the frequency goes up.

If the source is moving away from the receiver, the frequency goes down.


Doppler Use in Ultrasound

Doppler is used to evaluate blood flow where the ultrasound transducer is both the source and receiver of ultrasound waves.

The blood flow is in motion relative to the imaging transducer.



The system produces short bursts of ultrasound waves (TX) and listens to the reflected waves (RX) in between.

The same crystals are being used for transmit and receive of the ultrasound waves.

It uses the same pulse-echo technique in 2D imaging mode.

TX RX TX RXTXRX TX



PW allows us to sample at a specific depth along the Doppler line. This is represented by the sample volume ( Gate )

The velocity that PW can represent is limited.

Spectral Data is a representation of

the blood flow



The maximum depth for the sample volume in PW is limited by the transducer frequency.

The signal always alias at a certain point depending on the frequency of the transducer. Setting image parameters correctly is crucial for getting a clean image.

A good PW Doppler image has no noise in the background and a clean window in normal flow states.

Also, it should display accurate velocity and have clear audible signal. Spectral Data is a representation of the blood flow



Blood flow is towards the transducer

Velocity

Time

Spectral data in a PW image mode provides information about the direction, velocity and quality of the flow.


Direction of Flow in PW


Aliasing

Aliasing happens when Doppler sample rate is not adequate enough for high frequency shift.

When the velocity of the flow is too high to be displayed in the spectral window, the peaks are cut off and displayed below the baseline.


Aliasing

Aliasing:

Mirroring:


AUX Continuous Wave Doppler (AUX CW)

Uses different piezoelectric elements to send and receive ultrasound waves.

One element constantly sends ultrasound waves of a single frequency while another constantly receives the reflected waves.

No B-mode image is acquired or displayed.


AUX Continuous Wave Doppler (AUX CW)

AUX CW Doppler can display flow at any velocity without aliasing.

AUX CW Doppler cannot position the sample to listen at a specific depth.

Samples everything along the Doppler line.


Steered CW Doppler (CW)

This imaging mode is available on cardiac systems.

It utilizes an imaging transducer (phased array) to generate a CW Doppler image.


Color Doppler Ultrasound

Color Doppler provides a method to visualize blood flow and differentiate it from surrounding tissue.

It provides information about the presence of blood flow, its direction and speed.

Color Doppler utilizes pulse-echo Doppler flow principles to generate a color image.



This color image is superimposed on the 2D grayscale image.

The red and blue colors provide an indication of the flow velocity and direction.



The upper part of the color bar represents flow toward the transducer.

The bottom part of the color bar represents flow away from the transducer.



54

The color box in Color Doppler imaging mode must approach the vessel or heart chambers at an angle other than 90 degrees.

Otherwise, based on Doppler principles there will be little or no color at perpendicular incidence.


Velocity of Flow in Color Doppler UltrasoundColor Doppler is different from PW or CW because it provides an estimation of the average velocity using a technique called “Autocorrelation.”

Every reflected echo is correlated with the corresponding echo from the previous pulse to determine the motion that took place during that pulse.


Velocity of Flow in Color Doppler Ultrasound

The shade of the color determines the velocity of the flow.

For both red and blue colors, the darker the shade, the slower the flow. And, the lighter the shade, the faster the flow.


Aliasing in Color Doppler Ultrasound

When the velocity is faster than the lightest possible shade that can be displayed, aliasing occurs. This forces these peaks to wrap to the opposite color.

Adjusting the range of velocities that can be represented on the system eliminates this problem. The frequency of the transducer is a limiting factor.


What Defines a Good Color Doppler Image?

The color fills the entire blood vessel/chamber to its walls.

The walls are clear of any color.

The frame rate is adequate to display the blood flow.

Spatial resolution is good (the size of the color dot)


Power Doppler Ultrasound

Power Doppler Imaging (PDI) visualizes the integrated power of the Doppler signal instead of its frequency shift used in Color Doppler Imaging.

PDI does not carry directional or velocity information.

Power Doppler Imaging is also called Color Power Angio (CPA).


Passive LPF

TX

Beamformer

(FPGA)

Beamformer

Central

Control Unit

HV MUX/

DEMUX

T/R

Swithces

DAC

ADC

LNA TGCRx Buffer

Amp

Passive LPF

RX

Beamformer

(FPGA)

ADCCW (analog)

Beamformer

Spectral

Doppler

Processing (D-

Mode)

Image &

Motion

Processing (B-

Mode)

Color Doppler

(PW)

Processing (F-

Mode)

Data

Transmission

Audio

Amp

Audio

Output

* Texas Instruments

FET

Driver

Tx Buffer

AmpTransducer

Ultrasound Block Diagram


SonoCT Imaging

SonoCT Real-time Compound Imaging technology is a unique approach to overcome the inherent artifacts of conventional ultrasound that compromise image quality.

SonoCT imaging technology uses transmit beam-steering techniques to obtain co-planar, tomographic images from different viewing angles, then combines these micro-angulated images into a single compounded image at real-time frame rates.


SonoCT Imaging

Real-time spatial compound imaging (SonoCT) uses electronic beam steering of a transducer array to acquire multiple (3 to 9) overlapping scans of an object from different viewing angles.

The single-angle scans are averaged to form a multi-angle compound image that is updated in real time with each subsequent scan.

Compound imaging shows improved image quality compared with conventional ultrasound, primarily because of reduction of speckle, clutter and other acoustic artifacts.

Early clinical experience suggests that real-time spatial compound imaging can provide improved contrast resolution and tissue differentiation that is beneficial for imaging the breast, peripheral blood vessels and musculoskeletal injuries.


SonoCT Imaging

SonoCT imaging enables clinicians to acquire up to nine times more tissue information than the orthogonal beams used in conventional ultrasound, without any unusual manipulation of the transducer and without sacrificing frame rates.

SonoCT reduces angle-generated and speckle noise artifacts.

Structures with curved and irregular borders are more readily visualized.

Contrast resolution is improved and tissue margins are more discernable.

This powerful imaging technology is available on linear, curved and volumetric array transducers.

SonoCT produces images superior to conventional imaging in up to 94% of patients.


Harmonic Imaging

It’s an ultrasound imaging method in which the higher harmonic echoes (usually the second harmonic) of the fundamental (first harmonic) transmitted frequency are selectively detected and used for imaging.

Simulated beam profiles from the fundamental up to thefifth harmonic for a focused single element transducer.


Harmonic Imaging

The higher harmonics may have been created by non-linear scattering, e.g. from gas micro-bubbles or by non-linear propagation of the ultrasound pulse.

A large transducer bandwidth is needed for harmonic imaging since the receiver center frequency must be set to twice the center frequency of the transmitted pulse.

Ignoring original transmitted signal and receiving 4 MHz signal


Harmonic Imaging

When harmonic B-mode imaging is used to improve image quality and contrast resolution of tissues, the technique is called Tissue Harmonic Imaging (THI).

When harmonic Doppler ultrasound is used with micro-bubble contrast media (ultrasound contrast medium), the purpose is to improve detection of flow in small vessels by selectively enhancing the Doppler signal from blood and at the same time suppressing the echoes from surrounding tissue.


Panoramic Imaging

Panoramic Imaging is a feature of most contemporary ultrasound systems.

It is an imaging process that produces a panoramic image using conventional transducers and provides both qualitative and quantitative information.

Panoramic imaging broadens the scope of spatial relationships, thereby sequentially aligning individual images in their anatomical context.

Panoramic imaging has the ability to display an entire abnormality and show its relationship to adjacent structures on a single static image.


Panoramic Imaging

When producing a panoramic image, the transducer needs to be moved smoothly and in a precise direction.

If the object scanned is off plane or off the desired path, forward motion is discontinued and orientation can be corrected.

Image registration stops if the transducer is stationary.

Once the region of interest has been scanned, the panoramic image is saved and can be viewed on the monitor.


3D Ultrasound Imaging

In 3D mode the ultrasound waves are sent at different angles. The returning echoes are processed by the ultrasound system to reconstruct a three dimensional volume image of the internal organs. 3D ultrasound images allow us to see width, height and depth but no real time movement.


3D Ultrasound Imaging

3D ultrasound is a series of 2D images, rendered by the ultrasound system. The transducer sweeps left and right, collecting a series of 2D images.

“Surface rendering” allows for this series of images to be digitally interpreted by the system and displayed on the monitor.


Real Time 3D or 4D Ultrasound Imaging

Real-Time 3D or 4D imaging provides instant three dimensional images live. These images allow us to see width, height, depth and real-time movement.

This image can be captured using 3D matrix array transducers. Also, they can be generated using 3D mechanical array transducers.

Images shown are generated using 3D mechanical array transducers


Real Time 3D Ultrasound Imaging

Real-time 3D imaging is sometime called 4D imaging.

Recent advancements in computer technology and software engineering make 4D ultrasound imaging possible. Images shown below were generated using 3D matrix array transducers

Ultrasound System Blocks


This module covers the basic building blocks of any ultrasound system followed by some examples of various systems. Building Blocks of a Diagnostic Ultrasound System

Front End, Scanner, Coherent Image Former, or Acquisition Subsystem

Back End, Scan Converter, DIMAQ Workstation, or Platform Subsystem

Power Supply Subsystems – Low voltage and High Voltage Power Supplies

Operating System (OS) and Ultrasound Application Software


User Interface or Control Panel

Display Monitor – LCD or CRT based


Building Blocks of a Diagnostic Ultrasound System


Generic Ultrasound System

AC Input Box and Isolation Transformer

High Voltage Power Supply Low Voltage Power Supply

Probe n

:

Probe 2

Probe 1Front End,Scanner,

Front End Processor,Image Former,

or Acquisition Subsystem

Back End,Scan Converter,

Back End Processor, DIMAQ Workstation,

or Platform SubsystemDICOM

User Interface

Display

Operating System Software (OS)

Ultrasound Application Software

2D / M Color Doppler Power Doppler PW Doppler CW Doppler AUX CW

Harmonics 3D Real Time 3D


Probe Interface

Transmitter

Receiver

Beam former

Front End Controller

Probe Interface

Transmitter

Receiver

Beam Former

Front EndController

A generic front end contains the following components:

Front End subsystem


Back End Subsystem

A generic back end contains the following components:

System Master Controller

2D/M Signal Processor

PW/CW/Color Doppler Signal Processor

Image Memory & Video Layout

Video Processor

Peripheral Interface

PW/CW/ColorDoppler

Processor

2D/M Processor

ImageMemory

PeripheralInterface

VideoProcessor

System MasterController


Modular Block Diagram

AC Input Box and Isolation Transformer

High Voltage Power Supply Low Voltage Power Supply

Probe n

:

Probe 2

Probe 1

ProbeInterface

TransmitterFront End Controller

ReceiverBeam

Former

PW/CW/Color Doppler

Processor

ImageMemory

PeripheralInterface

2D/MProcessor

SystemMaster

Controller

VideoProcessor

DICOM Touch Panel

User Interface

Display

Operating System Software (OS)

Ultrasound Application Software

2D/M Color Doppler Power Doppler PW Doppler CW Doppler AUX CW

Harmonics 3D Real Time 3D


Front End Interconnections

Probe Interface

Receiver

Transmitter

Front EndController

Beam Former

Interface with the Back End

High VoltagePower Supply

HV TX Pulses

(-100/+100 V)

Ultrasound Signal

Multi Channels Ultrasound Signal (2D/M/Color/PW

Modes)

Programmable HV Output

HV Power Supply Control Signals

Line

Image

Ultrasound

Signal

Control Signals

HV Power Supply Input Voltages

TX/RX Signals

Front End Power from Main Power

Supply


Back End Interconnections

PW/CW/Color

DopplerProcessor

ImageMemory

SystemMaster

ControllerInterface with Front End

2D/MMode

Processor

VideoProcessor

PeripheralInterface

Low VoltagePower Supply

Ultrasound Signal (2D/M/Color/PW/CW Modes)

Ultrasound

Signal

Color/PW/

CW Mode

2D/M Mode

Video

Signal

Video Signal

Power to HV Power SupplyPower to all

Back End modules

Power to all Front End modules

Control

Signals


Four Channel Front End

HV Switchers

Frame 1

Linear Array

Probe

RX Amp

RX Amp

RX Amp

RX Amp

TX Amp

TX Amp

TX Amp

TX Amp

Active TX

Channels

RX Focus Pattern

Ch1 to 4

Transmitter

Receiver

TX Focus Pattern

Ch1 to 4

HV Pulses

A/D Converter

Data for 1st

Vertical Line

Control Signals from Back End

Line

1

Line

13

Front End Control

4 Channel Ultrasound Front EndInterfaced with a Linear Array Probe

Active RX Channels


Eight Channel Front EndHV SwitchersActive RX Channels

Active TX Channels

RX Focus

Pattern

Ch1 to 8

Transmitter

Receiver

TX Focus Pattern Ch1 to 8

Front End Control

HV Pulses

A/D Converter

Data for 1st

Image Line


Line

1

Line

N

Frame 1

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

TX Time Delay 8 Channel Ultrasound Front End Interfaced with a Phased Array Probe

Phased Array

Probe


RX Dynamic FocusHV Switchers

Active RX Channels

Active TX Channels

RX Focus

Pattern

Ch1 to 4

Transmitter

Receiver

TX Focus Pattern Ch1 to 8

Front End Control

HV Pulses

A/D Converter

Data for 1st

Image Line


Line

1

Line

N

Frame 1

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

RX AmpTX Amp

Rx Time Delay

Amplitude

RX Dynamic Focus for a Front End interfaced with a Phased Array Probe

Phased Array

Probe

Line 1

Line 2

Line 3

Line N


RX Dynamic Focus

Image Line 1

Frame 1

Frame 2

Frame 3

Frame NImage

Memory

Image Line 2

Image Line (X)

Image Line N

Digital Scan

Converter

VideoProcessor

System MasterController

Image Lin

e 1

Image Lin

e 2

Image Lin

e (X)

Image Lin

e N

System

DisplayFrame N-1

Frame 1

Frame N

Frame 1

Basic Back End Processor


Power Subsystems

High Voltage Power Supply:

Provides voltages to drive the probe’s elements (array) in the range of +150V/-150V.

Low Voltage Power Supply:

Provides +3.3/+5/-5/+12/-12/+15/-15 VDC to the Back End & Front End subsystems.

Ultrasound System Block Diagrams


Acuson Sequoia

GE Voluson 730

GE VIVID7

Philips iU22


Acuson Sequoia 512 Ultrasound System



APODZ./ DELAY/ GAIN

ACQUISITION BUS

TX APODZ. / DELAY

XDCR

TRANSMIT MULTIPLEXER

RECEIVE

MULTIPLEXER

TX / RX SWITCHING CONTROL

MP

AUX AMP

IMAGE FORMERSubsystem

SEQUOIA 512

MX

RX

LOW NOISE

VARIABLE GAIN

AMP

RX CONTROL

GAIN

SPECTRAL DOPPLER

PROCESSOR

MAINCLOCK

CW/PW

B/M/COLOR

BF

BF

ANALOG TO DIGITAL

CONVERTERBFP SUMMING

ANALOG TO DIGITAL

CONVERTERBFP SUMMING

TX-A

TX-B

H.V. Output Amp

DIGITAL TO ANALOG

CONVERTER

PROGRAMABLE WAVE

GENERATOR

H.V. Output Amp

DIGITAL TO ANALOG

CONVERTER

PROGRAMABLE WAVE

GENERATOR

RI

89



B / M DATA

F DATA

ACQUISITION CONTROL BUS

CN BDM

CSD

SYSTEM CENTRAL BUS

DIMAQ Integrated

Workstation

SEQUOIA 512

ACQUISITION CONTROL

FOCUS CONTROL

FILTERING

SUMMING

DMA

B/M

COLOR

DOPPLER

DATA

COLOR

SPECTRAL

AUDIOSYSTEM

DATA MEMORY

B/M ACQ. & PRE-

PROCESSING

SYSTEM DATA

MANAGER



VIDEO

DISPLAY

BUFFER

IMAGE

RECONSTRUCTION

SYSTEM SUPERVISORY PROCESSOR

RDP

IOV

I/O

PROCESSOR

VIDEOSTANDARDSCONVERTER

B/M/D/F/VCR DATA

AUDIO

AUDIO/ VCR PLAYBACK / PHYSIO

ETHERNET

JPEG

COPMRESSION/

DECOMPRESSIOE

PROGRESSIVE

VIDEO

PIC

SCSI

HD

MO

INTERNET CONNECTION

AEGIS

VCR PLAYBACK

SYSTEM AUDIO

PHYSIO

FPP

SWITCH ASSY

DISPLAY

USER INTERFACE

PPS

H.V.

MDI

POWER SUBSYSTEM

SEQUOIA 512

SPEAKERS

FIZ Module

VCR

Color Printer

Fan Tray


GE Voluson 730 Expert/Pro Ultrasound System


GE Voluson 730 Expert/Pro Block Diagram

CPK: Motherboard of GEF Module

CPN:

Main Power Supply Module

CRW:

CW

Doppler

Board

(Optional)

CRS: (BT03+)

This board replaces:

CPG, CPF,

CPC & CCM

Boards in

BT02 Expert

/Pro

CPR: Beamformer

32 CPD sub board

CPZ: Cover Board

CPV/CPU:

Probe Board

Provides

three probe

connectors

and an

optional

CW

connector

CPP:

Power Supply

Provides

+3.3/+5/+12/

+15/-15

+Fan(17-24)

TX Power

(-90/+90)

DC voltages

CPM:

PC Motherboard

CKV: Video Card-DMA Controller

CPE: Backplane

SBC: Single Board Computer

DVI:

Card (Expert only)

59 VDC CPE CPP

110 V AC

Front End Back End

H.D.

v

Monitor

User

Interface

CCFCPH

CPY

Standby Switch

GEM

59 VDC


GE Vivid 7 Ultrasound System



TXPower Supply

DCPower Supply

Display

Patient I/O

Internal I/O

AC Controller

TransformerBox

UPS

AC Input

Probe

BackEnd

Processor

FrontEnd

Processor

OperatorPanel

ExternalI/O



RX128

Relay

Board

TX128

BF64

BF64

FEC RFT SDP IMP

XD Bus Board

XD Bus Board

Backplane

Digital Signal Processors Subsystem

Pipe Link


Philips iU22 Ultrasound System



PSA

CB3

CB2

CB0

CB1

Scanhead Select

Acq Frontplane

NA I

M

FEC

Transducer

Platform Power Supply(PPS)

Acquisition Power Supply(APS)

AC Try

Power System & Battery Controller (PSBC)

Includes HV Switcher Function

DebugPort

HostUMB

DSC

HD0

UAVIO

HD1

HD2

USB

Touch Panel

Control Panel DVD Drive

Speakers

BypassPort

RFA & RFB

Control

PCI-E

PCI-E

DVI-D Video, 20 Inch Wide Screen

Signal and PowerDistribution (SPD)

OEMs

USBx6 to OEMs

CPC CPM


Glossary of Acronyms

AC – Alternating CurrentASIC – Application Specific Integrated CircuitADC – Analog to Digital Converter ATX – Advanced Technology eXtendedBF – Body FloatingCF – Cardiac FloatingCLA – Curved Linear Array (transducer)CPA – Color Power AngioCW – Continuous Wave (transducer)CMOS – Complementary Metal OxideDAC – Digital to Analog ConverterDGC – Depth Gain Control (same as TGC)DICOM – Digital Imaging and Communications in MedicineDNS – Domain Name ServerECG – ElectrocardiogramESU – Electo Surgical UnitFOV – Field of View

FPGA – Field Programmable Gate ArrayHV – High VoltageLNA – Low Noise AmplifierMRI – Magnetic Resonance ImagingPDI – Power Doppler Imaging PWT – Pulsed Wave TransducerPZT – Lead Zirconate Titanate (P=Pb)RIS – Radiology Information SystemRF – Radio FrequencyRLE – Run Length EncodingROI – Region of InterestTGC – Time Gain Control or Time Gain Compensation


GlossaryAcoustic energy – The amount of heat generated by the transmission of ultrasound. It is measured in joules.Acoustic power – The amount of acoustic energy generated per unit time. It is measured in watts. The biological effects of ultrasound in terms of power are in the milliwatt range.Acoustic output power – The rate at which acoustic energy leaves the transducer.Acoustic intensity – The acoustic power per unit cross-sectional area of the pulse. It is measured in watts per meter squared (W/m2) or in milliwatts per centimeter squared (mW/cm2).Apodization – A weighting function used as means of reducing side lobes in the beam.Application Entity – A node in a DICOM network.Axial resolution – Is also known as longitudinal resolution or azimuthal resolution is resolution in the direction parallel to the ultrasound beam. The resolution at any point along the beam is the same; therefore axial resolution is not affected by depth of imaging.Back End – System block on the user interface side that contains master controller, signal processing, image memory and video layout, peripheral and user interface.Beamforming – A common signal processing technique used to enable directionally or spatially selected signals to be sent or received from sensor arrays.B Mode – Brightness Mode Brightness Mode is the default mode that comes on when any ultrasound / echo machine is turned on. It is a 2 dimensional cross sectional view of the underlying structures made up of numerous B-mode scan lines.


Glossary

Cine – The cine mode is a series of rapidly recorded images taken sequentially and displayed in a dynamic movie display format.Digital Imaging and Communications in Medicine – A medical imaging standard for file format and network communications protocol for file sharing between entities capable of sending and receiving patient data and images in DICOM format.DisplayPort – A digital display interface standard administered by the Video Electronics Standards Association (VESA).Doppler effect – Change in the frequency of a periodic event (such as sound waves) due to a change in distance between the source and the observer.Doppler Range Gating – Range gate circuit only allows Doppler shift data from a user specified area to be displayed as output.Dynamic Host Configuration Protocol – A standardized network protocol used on IP networks for dynamically distributing network configuration parameters. IP addresses and networking parameters are requested automatically from a DHCP server, reducing the need to configure these settings manually.Electromagnetic Interference – (EMI) is when a radio frequency (RF) transmitting device interferes with the operation of another electronic device. In a healthcare environment wireless EMI can cause medical equipment to malfunction.Front End – System block that collects data; probe interface, transmitter/receiver, beamformer, front end controller.Harmonics – Ultrasound method that generates images using twice the frequency of the transmitted sound.


GlossaryI2C – Inter-IC bus, a two wire serial bus for communication between integrated circuits. Developed by Philips in the 1980’s it is now an industry standard.In Plane Switching – A type of thin film transistor LCD screen that has particularly good wide viewing angle and accurate color reproduction.Loops – Multiframe objects (e.g. video)M Mode – Motion ModeModality Performed Procedure Step – The modality provides information about a performed study, the number of images that were scanned and the status of the exam. The information is shared between a digital modality and the PACS and RIS.Multiplexing – Multiple signals transmitted over a single medium.Picture Archive and Communications Systems – DICOM Medical imaging storage server that stores images from diagnostic devices such as MRI, ultrasound and X-rays.Phased Array Ultrasound (3D imaging) – Sound waves are transmitted at different angles to obtain image.Physio – Refers to ECG inputs.Protocol Data Units – Message formats exchanged between peer entities within a layer. A PDU consists of protocol control information and user data.PS_ON – Refers to an active low signal used with all ATX and newer power supplies that use 20-24 pin motherboard connector. When high all voltages except 5V stand-by are disabled.Run-Length Encoding – A lossless compression method implemented by specifying the number of times a particular intensity value is repeated.


Glossary

Synthetic Aperture – An imaging method that improves resolution and depth of ultrasound images.Time Gain Compensation – Uses an array of sliding tabs which control the gain, which compensates for the difference of the strength of the ultrasound returning from varied distances to make the ultrasound image appear uniformly lit from top to bottom.Thin Film Transistor – A type of LCD display that uses active matrix technology.


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