Why use ultrasound for medical imaging? The 2019 Stack Overflow Developer Survey Results Are In Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Is there an upper frequency limit to ultrasound?How is it possible for an Ultrasound device to correctly interpret a negative density change in tissue?How specifically does an MRI machine build an image from received radio wavesIs it possible to send modulated ultrasound wave from underwater to air?Why the Doppler Ultrasound beam needs to be looking directly down at a pipeIntensity of an ultrasound beam?Dynamic range of ultrasound machine expressed in dBUltrasound wave/beam generationDoppler effect of sound waves in bloodAveraging speed of ultrasound between two differnt boundaires

Was credit for the black hole image misattributed?

Wall plug outlet change

Didn't get enough time to take a Coding Test - what to do now?

How to stretch delimiters to envolve matrices inside of a kbordermatrix?

What was the last x86 CPU that did not have the x87 floating-point unit built in?

Do working physicists consider Newtonian mechanics to be "falsified"?

Match Roman Numerals

How did passengers keep warm on sail ships?

Would an alien lifeform be able to achieve space travel if lacking in vision?

How is simplicity better than precision and clarity in prose?

Difference between "generating set" and free product?

Why can't wing-mounted spoilers be used to steepen approaches?

Program that generates brainfuck code that outputs given text

What LEGO pieces have "real-world" functionality?

Why is Captain Marvel translated as male in Portugal?

Is above average number of years spent on PhD considered a red flag in future academia or industry positions?

Did the UK government pay "millions and millions of dollars" to try to snag Julian Assange?

Python - Fishing Simulator

I'm thinking of a number

How to colour the US map with Yellow, Green, Red and Blue to minimize the number of states with the colour of Green

What aspect of planet Earth must be changed to prevent the industrial revolution?

What can I do if neighbor is blocking my solar panels intentionally?

Take groceries in checked luggage

Hiding Certain Lines on Table



Why use ultrasound for medical imaging?



The 2019 Stack Overflow Developer Survey Results Are In
Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Is there an upper frequency limit to ultrasound?How is it possible for an Ultrasound device to correctly interpret a negative density change in tissue?How specifically does an MRI machine build an image from received radio wavesIs it possible to send modulated ultrasound wave from underwater to air?Why the Doppler Ultrasound beam needs to be looking directly down at a pipeIntensity of an ultrasound beam?Dynamic range of ultrasound machine expressed in dBUltrasound wave/beam generationDoppler effect of sound waves in bloodAveraging speed of ultrasound between two differnt boundaires










1












$begingroup$


What advantage does ultrasound have over sound between 20-20000Hz that it is used in medical imaging over sound in that frequency range?










share|cite|improve this question









New contributor




Ubaid Hassan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$











  • $begingroup$
    your edits are quite helpful, but can I ask why you do edits so frequently?
    $endgroup$
    – Ubaid Hassan
    8 hours ago










  • $begingroup$
    Tagging is important, it helps people find things, helps the system that auto-identified related content, and enables meaningful analysis of site usage patterns. BUt good tagging takes time, attention to detail, and a minimum level of expertise so that you can identify the relevant tags.
    $endgroup$
    – dmckee
    8 hours ago










  • $begingroup$
    Homework-like question, lack of effort.
    $endgroup$
    – Pieter
    8 hours ago










  • $begingroup$
    you have a point, I’ll try to stop posting trivial questions from now on
    $endgroup$
    – Ubaid Hassan
    8 hours ago















1












$begingroup$


What advantage does ultrasound have over sound between 20-20000Hz that it is used in medical imaging over sound in that frequency range?










share|cite|improve this question









New contributor




Ubaid Hassan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$











  • $begingroup$
    your edits are quite helpful, but can I ask why you do edits so frequently?
    $endgroup$
    – Ubaid Hassan
    8 hours ago










  • $begingroup$
    Tagging is important, it helps people find things, helps the system that auto-identified related content, and enables meaningful analysis of site usage patterns. BUt good tagging takes time, attention to detail, and a minimum level of expertise so that you can identify the relevant tags.
    $endgroup$
    – dmckee
    8 hours ago










  • $begingroup$
    Homework-like question, lack of effort.
    $endgroup$
    – Pieter
    8 hours ago










  • $begingroup$
    you have a point, I’ll try to stop posting trivial questions from now on
    $endgroup$
    – Ubaid Hassan
    8 hours ago













1












1








1





$begingroup$


What advantage does ultrasound have over sound between 20-20000Hz that it is used in medical imaging over sound in that frequency range?










share|cite|improve this question









New contributor




Ubaid Hassan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




What advantage does ultrasound have over sound between 20-20000Hz that it is used in medical imaging over sound in that frequency range?







energy acoustics frequency wavelength medical-physics






share|cite|improve this question









New contributor




Ubaid Hassan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|cite|improve this question









New contributor




Ubaid Hassan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|cite|improve this question




share|cite|improve this question








edited 9 hours ago









Qmechanic

108k122001245




108k122001245






New contributor




Ubaid Hassan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 9 hours ago









Ubaid HassanUbaid Hassan

30311




30311




New contributor




Ubaid Hassan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





Ubaid Hassan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Ubaid Hassan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











  • $begingroup$
    your edits are quite helpful, but can I ask why you do edits so frequently?
    $endgroup$
    – Ubaid Hassan
    8 hours ago










  • $begingroup$
    Tagging is important, it helps people find things, helps the system that auto-identified related content, and enables meaningful analysis of site usage patterns. BUt good tagging takes time, attention to detail, and a minimum level of expertise so that you can identify the relevant tags.
    $endgroup$
    – dmckee
    8 hours ago










  • $begingroup$
    Homework-like question, lack of effort.
    $endgroup$
    – Pieter
    8 hours ago










  • $begingroup$
    you have a point, I’ll try to stop posting trivial questions from now on
    $endgroup$
    – Ubaid Hassan
    8 hours ago
















  • $begingroup$
    your edits are quite helpful, but can I ask why you do edits so frequently?
    $endgroup$
    – Ubaid Hassan
    8 hours ago










  • $begingroup$
    Tagging is important, it helps people find things, helps the system that auto-identified related content, and enables meaningful analysis of site usage patterns. BUt good tagging takes time, attention to detail, and a minimum level of expertise so that you can identify the relevant tags.
    $endgroup$
    – dmckee
    8 hours ago










  • $begingroup$
    Homework-like question, lack of effort.
    $endgroup$
    – Pieter
    8 hours ago










  • $begingroup$
    you have a point, I’ll try to stop posting trivial questions from now on
    $endgroup$
    – Ubaid Hassan
    8 hours ago















$begingroup$
your edits are quite helpful, but can I ask why you do edits so frequently?
$endgroup$
– Ubaid Hassan
8 hours ago




$begingroup$
your edits are quite helpful, but can I ask why you do edits so frequently?
$endgroup$
– Ubaid Hassan
8 hours ago












$begingroup$
Tagging is important, it helps people find things, helps the system that auto-identified related content, and enables meaningful analysis of site usage patterns. BUt good tagging takes time, attention to detail, and a minimum level of expertise so that you can identify the relevant tags.
$endgroup$
– dmckee
8 hours ago




$begingroup$
Tagging is important, it helps people find things, helps the system that auto-identified related content, and enables meaningful analysis of site usage patterns. BUt good tagging takes time, attention to detail, and a minimum level of expertise so that you can identify the relevant tags.
$endgroup$
– dmckee
8 hours ago












$begingroup$
Homework-like question, lack of effort.
$endgroup$
– Pieter
8 hours ago




$begingroup$
Homework-like question, lack of effort.
$endgroup$
– Pieter
8 hours ago












$begingroup$
you have a point, I’ll try to stop posting trivial questions from now on
$endgroup$
– Ubaid Hassan
8 hours ago




$begingroup$
you have a point, I’ll try to stop posting trivial questions from now on
$endgroup$
– Ubaid Hassan
8 hours ago










3 Answers
3






active

oldest

votes


















8












$begingroup$

I think the simple answer here is resolution.



Generally when imaging with waves (including light) the limit to resolution is a length that is similar to the wavelength, $lambda$.



If $f$ is the frequency and $c$ is the speed of the wave then the wavelength is given by



$$lambda = c over f $$



so the higher we make $f$ the smaller $lambda$ becomes and the better the resolution and the more detail we can see in scans....



The speed of sound in water is ~1500 m/s and with say 1.5 MHz = 1 500 000 Hz frequency we calculate



$$lambda = 0.001 rm m = 1 rm mm$$



At 20000 Hz $lambda = 75$ mm






share|cite|improve this answer











$endgroup$












  • $begingroup$
    Is it correct to say wavelength is inversely proportional to resolution? Or that sound wave frequency is directly proportional to resolution?
    $endgroup$
    – Ubaid Hassan
    8 hours ago






  • 1




    $begingroup$
    The correct statement is in terms of wavelength. That said, for non-dispersive waves (which is reasonably true for sound) in consistent media (not really true for medical ultra-sounds) the wavelength statements implies the frequency one as a corollary.
    $endgroup$
    – dmckee
    8 hours ago


















3












$begingroup$

Using waves for imaging, you want to distinguish points in the specimen. Consider the simplest case: you'd like to distinguish 2 discs (or spheres).



The waves are coming from behind the specimen passing through the circle or the waves are reflected on the circle. Considering the phase relationship of the waves at the detector (i.e. investigating interference) because of the diffraction on the 1 circle, even with focusing, one cannot get a single point on the detector. Take a look on the single slit diffraction and on the 2D version, on the Airy disk.



On the focused image you will get concentric circles. For $alpha$, the angular distance between the two most visible, inner ones one gets
$$lambda /left( 2d right) = sin left( alpha right) approx alpha ,$$
where $lambda$ corresponds to the wavelength and $d$ is the size of disc (therefore, your discs cannot be closer than this). With a huge, $180^circ$ imaging device one can resolve a distance of $lambda/2$. It can be seen that the achievable resolution (resolvable smallest distance) is proportional to wavelength.



And as it is known,
$$lambda = c/f,$$
where $c$ is the speed of the wave and $f$ is frequency, the higher the frequency, the smaller the wavelength is, increasing the achievable resolution.



Estimation



You can make an estimation on the achievable resolution. You'd like to do measurements in a human body. That consists of water mainly, the speed of sound in the water is $1500m/s$. At $20textKHz$ the resolvable distance is
$$frac1500textm/texts2 cdot 20textkHz = 3.75textcm.$$




We considered only 2D imaging here, but similar applies to 3D where you'd like to get information in 3D. In 3D one measures the time difference between the emission and detection of the signal, and using the $v=s/t$ formula, the distance of the object can be calculated.




share|cite|improve this answer











$endgroup$












  • $begingroup$
    Maybe "enter link description here" is not the link description you want.
    $endgroup$
    – dmckee
    8 hours ago


















2












$begingroup$

Higher frequency provides higher resolution.






share|cite|improve this answer









$endgroup$













    Your Answer








    StackExchange.ready(function()
    var channelOptions =
    tags: "".split(" "),
    id: "151"
    ;
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function()
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled)
    StackExchange.using("snippets", function()
    createEditor();
    );

    else
    createEditor();

    );

    function createEditor()
    StackExchange.prepareEditor(
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: false,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    bindNavPrevention: true,
    postfix: "",
    imageUploader:
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    ,
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    );



    );






    Ubaid Hassan is a new contributor. Be nice, and check out our Code of Conduct.









    draft saved

    draft discarded


















    StackExchange.ready(
    function ()
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphysics.stackexchange.com%2fquestions%2f472565%2fwhy-use-ultrasound-for-medical-imaging%23new-answer', 'question_page');

    );

    Post as a guest















    Required, but never shown

























    3 Answers
    3






    active

    oldest

    votes








    3 Answers
    3






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    8












    $begingroup$

    I think the simple answer here is resolution.



    Generally when imaging with waves (including light) the limit to resolution is a length that is similar to the wavelength, $lambda$.



    If $f$ is the frequency and $c$ is the speed of the wave then the wavelength is given by



    $$lambda = c over f $$



    so the higher we make $f$ the smaller $lambda$ becomes and the better the resolution and the more detail we can see in scans....



    The speed of sound in water is ~1500 m/s and with say 1.5 MHz = 1 500 000 Hz frequency we calculate



    $$lambda = 0.001 rm m = 1 rm mm$$



    At 20000 Hz $lambda = 75$ mm






    share|cite|improve this answer











    $endgroup$












    • $begingroup$
      Is it correct to say wavelength is inversely proportional to resolution? Or that sound wave frequency is directly proportional to resolution?
      $endgroup$
      – Ubaid Hassan
      8 hours ago






    • 1




      $begingroup$
      The correct statement is in terms of wavelength. That said, for non-dispersive waves (which is reasonably true for sound) in consistent media (not really true for medical ultra-sounds) the wavelength statements implies the frequency one as a corollary.
      $endgroup$
      – dmckee
      8 hours ago















    8












    $begingroup$

    I think the simple answer here is resolution.



    Generally when imaging with waves (including light) the limit to resolution is a length that is similar to the wavelength, $lambda$.



    If $f$ is the frequency and $c$ is the speed of the wave then the wavelength is given by



    $$lambda = c over f $$



    so the higher we make $f$ the smaller $lambda$ becomes and the better the resolution and the more detail we can see in scans....



    The speed of sound in water is ~1500 m/s and with say 1.5 MHz = 1 500 000 Hz frequency we calculate



    $$lambda = 0.001 rm m = 1 rm mm$$



    At 20000 Hz $lambda = 75$ mm






    share|cite|improve this answer











    $endgroup$












    • $begingroup$
      Is it correct to say wavelength is inversely proportional to resolution? Or that sound wave frequency is directly proportional to resolution?
      $endgroup$
      – Ubaid Hassan
      8 hours ago






    • 1




      $begingroup$
      The correct statement is in terms of wavelength. That said, for non-dispersive waves (which is reasonably true for sound) in consistent media (not really true for medical ultra-sounds) the wavelength statements implies the frequency one as a corollary.
      $endgroup$
      – dmckee
      8 hours ago













    8












    8








    8





    $begingroup$

    I think the simple answer here is resolution.



    Generally when imaging with waves (including light) the limit to resolution is a length that is similar to the wavelength, $lambda$.



    If $f$ is the frequency and $c$ is the speed of the wave then the wavelength is given by



    $$lambda = c over f $$



    so the higher we make $f$ the smaller $lambda$ becomes and the better the resolution and the more detail we can see in scans....



    The speed of sound in water is ~1500 m/s and with say 1.5 MHz = 1 500 000 Hz frequency we calculate



    $$lambda = 0.001 rm m = 1 rm mm$$



    At 20000 Hz $lambda = 75$ mm






    share|cite|improve this answer











    $endgroup$



    I think the simple answer here is resolution.



    Generally when imaging with waves (including light) the limit to resolution is a length that is similar to the wavelength, $lambda$.



    If $f$ is the frequency and $c$ is the speed of the wave then the wavelength is given by



    $$lambda = c over f $$



    so the higher we make $f$ the smaller $lambda$ becomes and the better the resolution and the more detail we can see in scans....



    The speed of sound in water is ~1500 m/s and with say 1.5 MHz = 1 500 000 Hz frequency we calculate



    $$lambda = 0.001 rm m = 1 rm mm$$



    At 20000 Hz $lambda = 75$ mm







    share|cite|improve this answer














    share|cite|improve this answer



    share|cite|improve this answer








    edited 9 hours ago

























    answered 9 hours ago









    tomtom

    6,42711627




    6,42711627











    • $begingroup$
      Is it correct to say wavelength is inversely proportional to resolution? Or that sound wave frequency is directly proportional to resolution?
      $endgroup$
      – Ubaid Hassan
      8 hours ago






    • 1




      $begingroup$
      The correct statement is in terms of wavelength. That said, for non-dispersive waves (which is reasonably true for sound) in consistent media (not really true for medical ultra-sounds) the wavelength statements implies the frequency one as a corollary.
      $endgroup$
      – dmckee
      8 hours ago
















    • $begingroup$
      Is it correct to say wavelength is inversely proportional to resolution? Or that sound wave frequency is directly proportional to resolution?
      $endgroup$
      – Ubaid Hassan
      8 hours ago






    • 1




      $begingroup$
      The correct statement is in terms of wavelength. That said, for non-dispersive waves (which is reasonably true for sound) in consistent media (not really true for medical ultra-sounds) the wavelength statements implies the frequency one as a corollary.
      $endgroup$
      – dmckee
      8 hours ago















    $begingroup$
    Is it correct to say wavelength is inversely proportional to resolution? Or that sound wave frequency is directly proportional to resolution?
    $endgroup$
    – Ubaid Hassan
    8 hours ago




    $begingroup$
    Is it correct to say wavelength is inversely proportional to resolution? Or that sound wave frequency is directly proportional to resolution?
    $endgroup$
    – Ubaid Hassan
    8 hours ago




    1




    1




    $begingroup$
    The correct statement is in terms of wavelength. That said, for non-dispersive waves (which is reasonably true for sound) in consistent media (not really true for medical ultra-sounds) the wavelength statements implies the frequency one as a corollary.
    $endgroup$
    – dmckee
    8 hours ago




    $begingroup$
    The correct statement is in terms of wavelength. That said, for non-dispersive waves (which is reasonably true for sound) in consistent media (not really true for medical ultra-sounds) the wavelength statements implies the frequency one as a corollary.
    $endgroup$
    – dmckee
    8 hours ago











    3












    $begingroup$

    Using waves for imaging, you want to distinguish points in the specimen. Consider the simplest case: you'd like to distinguish 2 discs (or spheres).



    The waves are coming from behind the specimen passing through the circle or the waves are reflected on the circle. Considering the phase relationship of the waves at the detector (i.e. investigating interference) because of the diffraction on the 1 circle, even with focusing, one cannot get a single point on the detector. Take a look on the single slit diffraction and on the 2D version, on the Airy disk.



    On the focused image you will get concentric circles. For $alpha$, the angular distance between the two most visible, inner ones one gets
    $$lambda /left( 2d right) = sin left( alpha right) approx alpha ,$$
    where $lambda$ corresponds to the wavelength and $d$ is the size of disc (therefore, your discs cannot be closer than this). With a huge, $180^circ$ imaging device one can resolve a distance of $lambda/2$. It can be seen that the achievable resolution (resolvable smallest distance) is proportional to wavelength.



    And as it is known,
    $$lambda = c/f,$$
    where $c$ is the speed of the wave and $f$ is frequency, the higher the frequency, the smaller the wavelength is, increasing the achievable resolution.



    Estimation



    You can make an estimation on the achievable resolution. You'd like to do measurements in a human body. That consists of water mainly, the speed of sound in the water is $1500m/s$. At $20textKHz$ the resolvable distance is
    $$frac1500textm/texts2 cdot 20textkHz = 3.75textcm.$$




    We considered only 2D imaging here, but similar applies to 3D where you'd like to get information in 3D. In 3D one measures the time difference between the emission and detection of the signal, and using the $v=s/t$ formula, the distance of the object can be calculated.




    share|cite|improve this answer











    $endgroup$












    • $begingroup$
      Maybe "enter link description here" is not the link description you want.
      $endgroup$
      – dmckee
      8 hours ago















    3












    $begingroup$

    Using waves for imaging, you want to distinguish points in the specimen. Consider the simplest case: you'd like to distinguish 2 discs (or spheres).



    The waves are coming from behind the specimen passing through the circle or the waves are reflected on the circle. Considering the phase relationship of the waves at the detector (i.e. investigating interference) because of the diffraction on the 1 circle, even with focusing, one cannot get a single point on the detector. Take a look on the single slit diffraction and on the 2D version, on the Airy disk.



    On the focused image you will get concentric circles. For $alpha$, the angular distance between the two most visible, inner ones one gets
    $$lambda /left( 2d right) = sin left( alpha right) approx alpha ,$$
    where $lambda$ corresponds to the wavelength and $d$ is the size of disc (therefore, your discs cannot be closer than this). With a huge, $180^circ$ imaging device one can resolve a distance of $lambda/2$. It can be seen that the achievable resolution (resolvable smallest distance) is proportional to wavelength.



    And as it is known,
    $$lambda = c/f,$$
    where $c$ is the speed of the wave and $f$ is frequency, the higher the frequency, the smaller the wavelength is, increasing the achievable resolution.



    Estimation



    You can make an estimation on the achievable resolution. You'd like to do measurements in a human body. That consists of water mainly, the speed of sound in the water is $1500m/s$. At $20textKHz$ the resolvable distance is
    $$frac1500textm/texts2 cdot 20textkHz = 3.75textcm.$$




    We considered only 2D imaging here, but similar applies to 3D where you'd like to get information in 3D. In 3D one measures the time difference between the emission and detection of the signal, and using the $v=s/t$ formula, the distance of the object can be calculated.




    share|cite|improve this answer











    $endgroup$












    • $begingroup$
      Maybe "enter link description here" is not the link description you want.
      $endgroup$
      – dmckee
      8 hours ago













    3












    3








    3





    $begingroup$

    Using waves for imaging, you want to distinguish points in the specimen. Consider the simplest case: you'd like to distinguish 2 discs (or spheres).



    The waves are coming from behind the specimen passing through the circle or the waves are reflected on the circle. Considering the phase relationship of the waves at the detector (i.e. investigating interference) because of the diffraction on the 1 circle, even with focusing, one cannot get a single point on the detector. Take a look on the single slit diffraction and on the 2D version, on the Airy disk.



    On the focused image you will get concentric circles. For $alpha$, the angular distance between the two most visible, inner ones one gets
    $$lambda /left( 2d right) = sin left( alpha right) approx alpha ,$$
    where $lambda$ corresponds to the wavelength and $d$ is the size of disc (therefore, your discs cannot be closer than this). With a huge, $180^circ$ imaging device one can resolve a distance of $lambda/2$. It can be seen that the achievable resolution (resolvable smallest distance) is proportional to wavelength.



    And as it is known,
    $$lambda = c/f,$$
    where $c$ is the speed of the wave and $f$ is frequency, the higher the frequency, the smaller the wavelength is, increasing the achievable resolution.



    Estimation



    You can make an estimation on the achievable resolution. You'd like to do measurements in a human body. That consists of water mainly, the speed of sound in the water is $1500m/s$. At $20textKHz$ the resolvable distance is
    $$frac1500textm/texts2 cdot 20textkHz = 3.75textcm.$$




    We considered only 2D imaging here, but similar applies to 3D where you'd like to get information in 3D. In 3D one measures the time difference between the emission and detection of the signal, and using the $v=s/t$ formula, the distance of the object can be calculated.




    share|cite|improve this answer











    $endgroup$



    Using waves for imaging, you want to distinguish points in the specimen. Consider the simplest case: you'd like to distinguish 2 discs (or spheres).



    The waves are coming from behind the specimen passing through the circle or the waves are reflected on the circle. Considering the phase relationship of the waves at the detector (i.e. investigating interference) because of the diffraction on the 1 circle, even with focusing, one cannot get a single point on the detector. Take a look on the single slit diffraction and on the 2D version, on the Airy disk.



    On the focused image you will get concentric circles. For $alpha$, the angular distance between the two most visible, inner ones one gets
    $$lambda /left( 2d right) = sin left( alpha right) approx alpha ,$$
    where $lambda$ corresponds to the wavelength and $d$ is the size of disc (therefore, your discs cannot be closer than this). With a huge, $180^circ$ imaging device one can resolve a distance of $lambda/2$. It can be seen that the achievable resolution (resolvable smallest distance) is proportional to wavelength.



    And as it is known,
    $$lambda = c/f,$$
    where $c$ is the speed of the wave and $f$ is frequency, the higher the frequency, the smaller the wavelength is, increasing the achievable resolution.



    Estimation



    You can make an estimation on the achievable resolution. You'd like to do measurements in a human body. That consists of water mainly, the speed of sound in the water is $1500m/s$. At $20textKHz$ the resolvable distance is
    $$frac1500textm/texts2 cdot 20textkHz = 3.75textcm.$$




    We considered only 2D imaging here, but similar applies to 3D where you'd like to get information in 3D. In 3D one measures the time difference between the emission and detection of the signal, and using the $v=s/t$ formula, the distance of the object can be calculated.





    share|cite|improve this answer














    share|cite|improve this answer



    share|cite|improve this answer








    edited 7 hours ago

























    answered 8 hours ago









    DanielTuzesDanielTuzes

    21816




    21816











    • $begingroup$
      Maybe "enter link description here" is not the link description you want.
      $endgroup$
      – dmckee
      8 hours ago
















    • $begingroup$
      Maybe "enter link description here" is not the link description you want.
      $endgroup$
      – dmckee
      8 hours ago















    $begingroup$
    Maybe "enter link description here" is not the link description you want.
    $endgroup$
    – dmckee
    8 hours ago




    $begingroup$
    Maybe "enter link description here" is not the link description you want.
    $endgroup$
    – dmckee
    8 hours ago











    2












    $begingroup$

    Higher frequency provides higher resolution.






    share|cite|improve this answer









    $endgroup$

















      2












      $begingroup$

      Higher frequency provides higher resolution.






      share|cite|improve this answer









      $endgroup$















        2












        2








        2





        $begingroup$

        Higher frequency provides higher resolution.






        share|cite|improve this answer









        $endgroup$



        Higher frequency provides higher resolution.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered 9 hours ago









        akhmeteliakhmeteli

        18.5k21844




        18.5k21844




















            Ubaid Hassan is a new contributor. Be nice, and check out our Code of Conduct.









            draft saved

            draft discarded


















            Ubaid Hassan is a new contributor. Be nice, and check out our Code of Conduct.












            Ubaid Hassan is a new contributor. Be nice, and check out our Code of Conduct.











            Ubaid Hassan is a new contributor. Be nice, and check out our Code of Conduct.














            Thanks for contributing an answer to Physics Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid


            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.

            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function ()
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphysics.stackexchange.com%2fquestions%2f472565%2fwhy-use-ultrasound-for-medical-imaging%23new-answer', 'question_page');

            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Reverse int within the 32-bit signed integer range: [−2^31, 2^31 − 1]Combining two 32-bit integers into one 64-bit integerDetermine if an int is within rangeLossy packing 32 bit integer to 16 bitComputing the square root of a 64-bit integerKeeping integer addition within boundsSafe multiplication of two 64-bit signed integersLeetcode 10: Regular Expression MatchingSigned integer-to-ascii x86_64 assembler macroReverse the digits of an Integer“Add two numbers given in reverse order from a linked list”

            Category:Fedor von Bock Media in category "Fedor von Bock"Navigation menuUpload mediaISNI: 0000 0000 5511 3417VIAF ID: 24712551GND ID: 119294796Library of Congress authority ID: n96068363BnF ID: 12534305fSUDOC authorities ID: 034604189Open Library ID: OL338253ANKCR AUT ID: jn19990000869National Library of Israel ID: 000514068National Thesaurus for Author Names ID: 341574317ReasonatorScholiaStatistics

            Kiel Indholdsfortegnelse Historie | Transport og færgeforbindelser | Sejlsport og anden sport | Kultur | Kendte personer fra Kiel | Noter | Litteratur | Eksterne henvisninger | Navigationsmenuwww.kiel.de54°19′31″N 10°8′26″Ø / 54.32528°N 10.14056°Ø / 54.32528; 10.14056Oberbürgermeister Dr. Ulf Kämpferwww.statistik-nord.deDen danske Stats StatistikKiels hjemmesiderrrWorldCat312794080n790547494030481-4