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Why use ultrasound for medical imaging?

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?

energy acoustics frequency wavelength medical-physics

share|cite|improve this question

edited 59 mins ago

Qmechanic♦

108k122001245

asked 1 hour ago

Ubaid HassanUbaid Hassan

19511

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
  20 mins 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♦
  16 mins ago
  

  
  
  
  

add a comment | 

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?

energy acoustics frequency wavelength medical-physics

share|cite|improve this question

edited 59 mins ago

Qmechanic♦

108k122001245

asked 1 hour ago

Ubaid HassanUbaid Hassan

19511

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
  20 mins 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♦
  16 mins ago
  

  
  
  
  

add a comment | 

$begingroup$

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

edited 59 mins ago

Qmechanic♦

108k122001245

asked 1 hour ago

Ubaid HassanUbaid Hassan

19511

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.

$endgroup$

share|cite|improve this question

edited 59 mins ago

Qmechanic♦

108k122001245

asked 1 hour ago

Ubaid HassanUbaid Hassan

19511

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

edited 59 mins ago

Qmechanic♦

108k122001245

asked 1 hour ago

Ubaid HassanUbaid Hassan

19511

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.

edited 59 mins ago

Qmechanic♦

108k122001245

edited 59 mins ago

Qmechanic♦

108k122001245

asked 1 hour ago

Ubaid HassanUbaid Hassan

19511

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 1 hour ago

Ubaid HassanUbaid Hassan

19511

2 Answers
2

active

oldest

votes

4

$begingroup$

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

edited 42 mins ago

answered 1 hour ago

tomtom

6,38711627

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

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

  
  
  
  

add a comment | 

1

$begingroup$

Higher frequency provides higher resolution.

share|cite|improve this answer

answered 1 hour ago

akhmeteliakhmeteli

18.5k21844

$endgroup$

add a comment | 

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4

$begingroup$

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

edited 42 mins ago

answered 1 hour ago

tomtom

6,38711627

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

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

  
  
  
  

add a comment | 

4

$begingroup$

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

edited 42 mins ago

answered 1 hour ago

tomtom

6,38711627

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

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

  
  
  
  

add a comment | 

$begingroup$

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

edited 42 mins ago

answered 1 hour ago

tomtom

6,38711627

$endgroup$

share|cite|improve this answer

edited 42 mins ago

answered 1 hour ago

tomtom

6,38711627

answered 1 hour ago

tomtom

6,38711627

answered 1 hour ago

tomtom

6,38711627

1

$begingroup$

Higher frequency provides higher resolution.

share|cite|improve this answer

answered 1 hour ago

akhmeteliakhmeteli

18.5k21844

$endgroup$

add a comment | 

1

$begingroup$

Higher frequency provides higher resolution.

share|cite|improve this answer

answered 1 hour ago

akhmeteliakhmeteli

18.5k21844

$endgroup$

add a comment | 

$begingroup$

Higher frequency provides higher resolution.

share|cite|improve this answer

answered 1 hour ago

akhmeteliakhmeteli

18.5k21844

$endgroup$

share|cite|improve this answer

answered 1 hour ago

akhmeteliakhmeteli

18.5k21844

answered 1 hour ago

akhmeteliakhmeteli

18.5k21844

answered 1 hour ago

akhmeteliakhmeteli

18.5k21844