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the problem is that more and more of us see these on digital archives with 
DICOM format- DICOM standard has no place for sound, I miss it as much as 
you, but we won't see it again unless we change archive file formats
Joe

At 05:53 PM 4/17/2006 -0400, you wrote:
>Hear, Hear....:)  Interpreting MD's should also know how to hear a poor or a
>good signal. the audio signal is a great clue to whether the signal is hidden
>behind some noise or a jet is being missed.  Claudia
>
>Quoting Chris Walker <[log in to unmask]>:
>
> > Well stated Wayne...
> >
> > Every echocardiography tech has had the experience of hearing a 
> stenotic or
> > regurgitant jet and struggled with displaying the associated spectral wave
> > form.  One might argue that these hemodynamic conditions are clinically
> > insignificant.  However, a tight carotid stenosis versus totally occluded
> > carotid artery is markedly different from a diagnostic perspective.
> >
> > Therefore, I too agree that omitting scrolling spectral Doppler display 
> with
> >
> > audio from the DICOM capturing standard was a mistake.  If the vascular
> > community is to embrace and broadly adopt DICOM PACS it's obvious the
> > standard must change in this regard.   I'm surprised their voice of
> > resistance has not resulted in change to date.
> >
> > This said, the vascular community should plan on ECG triggering as part of
> > their study protocol or the storage requirements imposed from capturing 
> long
> >
> > clips versus shorter heart beat loops will cause resistance from those who
> > manage storage economics.
> >
> > Perhaps it could be made an option within the standard and also user
> > selectable by application on the ultrasound system.  I can't imagine the
> > ultrasound manufacturers would resist this as this represents software
> > upgrade revenue from installed base users and a reason to buy new 
> equipment
> > if this change is implemented.
> >
> > By addressing it as an option within the standard and user selectable by
> > application... it allows those who are comfortable with frame Doppler
> > captures to maintain their clinical use model while others who feel
> > scrolling spectral Doppler displays with audio is a clinical necessity 
> will
> > adopt DICOM PACS.
> >
> > This is a subject linked to diagnostic confidence and not a one size fits
> > all issue and needs to be addressed by the DICOM committee.
> >
> > Chris Walker @ CVS
> >
> >
> > ----- Original Message -----
> > From: "Wayne Moore" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Monday, April 17, 2006 7:46 AM
> > Subject: RE: [echocardiography] Re: Doppler audio and digital clips
> >
> >
> > > With all due respect, your comment lacks understanding of the role of
> > > audio
> > > in concert with the spectral display. Variants in the tonal quality of a
> > > Doppler audio signal associated with mild to moderate lesions are often
> > > heard by the echocardiographer before a complete spectral waveform can be
> > > visualized (i.e., developed) on the display. Indeed, experienced echo
> > > users
> > > use these tone variants to guide the fine positioning of the 
> transducer to
> > > maximize the intensity and completeness of the spectral display. Anyone
> > > who
> > > has experienced the challenge of obtaining a complete spectral 
> waveform in
> > > cases of mild aortic insufficiency can attest to this. From an engineers
> > > perspective the question is one of dynamic range and the low energy
> > > content
> > > resident in the higher frequencies (i.e., higher velocities). Due to the
> > > limited display dynamic range of monitors the wide range of returning
> > > Doppler signals must be significantly compressed in order to be 
> displayed.
> > > Even with very generous logarithmic (log) compression the monitor cannot
> > > go
> > > much beyond 40dB of displayed dynamic range, and more typically winds up
> > > nearer to 30dB. The audio detector - the human ear, is much better at
> > > hearing the low energy high frequencies, thus these signals are often
> > > heard
> > > before they are seen. Modern ultrasound systems have controls that allow
> > > the
> > > operator to "window" compress over the entire dynamic range of the
> > > ultrasound system. Once the flow variant is heard, the operator can 
> select
> >
> > > a
> > > log compression that will bias the display toward that frequency range,
> > > where you then have your best chance to produce a complete spectral
> > > waveform. I would also take exception to the comment that manufacturers
> > > have
> > > kept audio in the ultrasound systems merely as a "feature". A "feature"
> > > that
> > > is not used by echocardiographers ceases to be a feature and instead
> > > becomes
> > > engineering overhead both in the design phase as well as in the 
> sustaining
> > > engineering phase. Hardly redundant, Doppler audio can be, and has 
> proven
> > > to
> > > be an extremely helpful tool in the hands of a careful echocardiographer.
> > >
> > > G. Wayne Moore, BSEE, MA
> > > President and CEO
> > > Sonora Medical Systems
> > > 1751 S. Fordham St Longmont, Colorado 80503
> > > (888) 476-6672
> > > Http:\\www.4sonora.com
> > >
> > > This message and any included attachments are from Sonora Medical Systems
> > > Inc. and are intended only for the addressee(s). The information 
> contained
> > > herein may include trade secrets or privileged or otherwise confidential
> > > information. Unauthorized review, forwarding, printing, copying,
> > > distributing, or using such information is strictly prohibited and may be
> > > unlawful. If you received this message in error, or have reason to 
> believe
> > > you are not authorized to receive it, please promptly delete this message
> > > and notify the sender by e-mail with a copy to [log in to unmask]
> > >
> > > Thank you
> > >
> > > -----Original Message-----
> > > From: [log in to unmask]
> > > [mailto:[log in to unmask]]On Behalf Of Dr. George Thomas
> > > Sent: Friday, April 14, 2006 11:57 PM
> > > To: [log in to unmask]
> > > Subject: [echocardiography] Re: Doppler audio and digital clips
> > >
> > > Dear Andy:
> > >
> > > I agree with you. Audio was used during the "blind" Doppler era, when
> > > spectral displays were not available. Now that the spectral displays
> > > are available, audio becomes redundant. However, manufacturers have
> > > retained this facility because they would not like to decrease
> > > the "features" of a machine. Have you tried audio in tissue Doppler
> > > mode? This can be used as a percussion instrument for a rock show!
> > >
> > > Dr. George Thomas
> > > Kochi, India
> > >
> > >
> > > --- In [log in to unmask], "Andrew Horning"
> > > <andrewhorning@...> wrote:
> > >>
> > >> Sonographers already/still do have the sound while they're
> > > obtaining the
> > >> study.  I've not yet heard a reading physician claim to need
> > > audio.  Is
> > >> audio playback a real need?  Technically, it's not difficult to
> > > acquire
> > >> and synchronize digital sound and clips.  Heck; we could digitally
> > >> acquire stethoscope sounds too, for that matter.
> > >> But the decision was made some time ago not to acquire digital audio
> > >> with ultrasound because this was deemed unnecessary.
> > >> Will a reading physician chime in?
> > >>
> > >> Andy Horning
> > >> The Freedom Farm
> > >> 7851 Pleasant Hill Road
> > >> Freedom, Indiana  47431
> > >>
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Yahoo! Groups Links
> > >
> > > <*> To visit your group on the web, go to:
> > >    http://groups.yahoo.com/group/echocardiography/
> > >
> > > <*> To unsubscribe from this group, send an email to:
> > >    [log in to unmask]
> > >
> > > <*> Your use of Yahoo! Groups is subject to:
> > >    http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> > >
> >
> > To unsubscribe or search other topics on UVM Flownet link to:
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> >
>
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Joseph R. Schneider, MD, PhD
Professor, Vascular Surgery
Associate Director, Northwestern General Surgery Residency
Northwestern University Medical School

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