[Tubetk-developers] GradientBasedAngleOfIncidenceImageFilter

[Matt McCormick]

On Wed, Aug 29, 2012 at 8:46 PM, Stephen Aylward
<stephen.aylward at kitware.com> wrote:
> Shouldn't the vessels be bright on all edges aligned with the gradient
> normal - regardless of the sign.   That is, shouldn't the near and far
> edges of the vessels be bright - not just the near ones, as shown?
> And this applies to every object's edges (liver, etc.).
>
> For example, see
> http://www.medison.ru/uzi/eho398.htm
> http://www.medison.ru/uzi/eho240.htm
> and
> google "ultrasound of liver" and look at the images.

Yes, correct.

This filter is one step to getting there.  Other steps to take:

The ultrasound signal intensity is the result of the product of the
angle of incidence with a term that depends on the magnitude of the
acoustic impedance gradient (e.g. Wein 2007 Eqn. 3).  So, we still
have to compute the result.

The near and far walls will be bright then after taking the absolute
value.  It seems more appropriate to take the absolute value at a
later stage so that the angle of incidence filter can possibly be used
for other purposes that take advantage of the sign.

We can also isolate the sparse "informative points", organ boundaries
and vessels walls, where these type of specular reflections will occur
from large scatterers (Szabo section 9.2, 11-Chap09.pdf), possibly
using Andinet's sheetness filter.

Thanks,
Matt

>
> s
>
> On Wed, Aug 29, 2012 at 6:32 PM, Matt McCormick
> <matt.mccormick at kitware.com> wrote:
>> Hi Andinet,
>>
>> I merged the GradientBasedAngleOfIncidenceImageFilter.  Renderings of
>> the test outputs are attached.  I'll create another filter to
>> calculate the reflected intensity and fix any dashboard issues that
>> crop up tomorrow.  We are now up to 600 tests -- woohoo! :-)
>>
>> Thanks,
>> Matt
>>
>> _______________________________________________
>> Tubetk-developers mailing list
>> Tubetk-developers at tubetk.org
>> http://public.kitware.com/cgi-bin/mailman/listinfo/tubetk-developers
>>
>
>
>
> --
>
> ==============================
> Stephen R. Aylward, Ph.D.
> Senior Director of Operations - North Carolina
> Kitware, Inc. - North Carolina Office
> http://www.kitware.com
> stephen.aylward (Skype)
> (919) 969-6990 x300