{Spam?} Re: [Insight-users] Kideny Segmentation

Emiliano Beronich emiliano at veccsa.com
Tue Feb 21 14:27:53 EST 2006


Luis,
the images are from a nuclear medicine dynamic study, a 2D projection 
over a fixed detector, measuring changes over time. The images are 2D 
spatially and the third dimension is for change over time. So basically 
we are segmenting a 2D image like those I have showed you. It is not 
expected to have access to images of the same patient from another 
modality. The final target is to get the contour of kidneys.

The shape of the kidney is very variable from one image to another. I 
would like to know if the deformation model could recognize such a 
change in shape. After viewing the images, do you still think that Model 
Based Segmentation can be applicable?

Thanks again Luis,
Emiliano


Luis Ibanez escribió:

> 
> Hi Emiliano,
> 
> Thanks for posting the screen shots of the gamma
> camera images that you are trying to segment.
> 
> The information on these images doesn't seem to
> be enough for describing the anatomical shape
> of the Kidney.
> 
> Would you have access to images of the same
> patient acquired in another modality ?
> 
> For example CT ?
> 
> If so, then you could extract the Kidney from
> that other modality and then use it as a model
> for registering against the gamma camera images.
> 
> Do you have access to a 3D volume of images from
> the gamma camera ?
> 
> or are you only dealing with a 2D projection of the
> image (like X-rays) and its changes over time ?
> 
> The matching process will be different depending
> on whether you are searching for an object in a
> projection image or an object embedded in a 3D volume.
> 
> 
> Please let us know more details about the gamma
> camera images that you posted.
> 
> 
>     Thanks
> 
> 
> 
>       Luis
> 
> 
> --------------------------
> Emiliano Beronich wrote:
> 
>> Thanks for your answer, Luis. I've posted some images.
>>
>> http://www.veccsa.com/images/thumbs.png
>>
>> This one presents intensity irregularities inside the kidneys,
>> http://www.veccsa.com/images/0001602.png
>>
>> The irregularities inside the kidney change the gradient and add a 
>> potential edge difficult to discriminate without other considerations.
>>
>> Diffuse edges,
>> http://www.veccsa.com/images/0002201.png
>>
>> Different intensities between left and right kidney,
>> http://www.veccsa.com/images/0003101.png
>>
>> The final target is to get a contour of the kidney. I hope this images 
>> allows you to get a better idea of the problem. I'm reading about 
>> Model based registration.
>>
>> Regards,
>> Emiliano
>>
>>
>>
>> Luis Ibanez escribió:
>>
>>>
>>> Hi Emiliano,
>>>
>>> Can you post in a web site a couple of screen shots of your images ?
>>>
>>> That will help a lot to figure out the degree of irregularities
>>> in your images.
>>>
>>> If you are having to deal simultaneously with:
>>>
>>>   1) Different intensities between left and right kidney
>>>   2) Intensity irregularities inside the kidneys
>>>   3) Diffuse edges
>>>
>>>
>>> Then you probably may want to use model-based segmentation.
>>>
>>> In this approach you create a geometrical model of a kidney
>>> (e.g. by segmenting a typical kidney from another modality
>>> such as CT or MR where the kidney anatomy will be better
>>> defined).  Then you register this geometrical model against
>>> the gamma camera image that you have.
>>>
>>> You will find a description of this method at the end of the
>>> Image Registration chapter of the ITK Software Guide:
>>>
>>>        http://www.itk.org/ItkSoftwareGuide.pdf
>>>
>>>
>>> As any other segmentation method, this approach has some
>>> advantages and disadvantages, but, given the constrains
>>> that you listed in your email, it seems to be more appropriate
>>> than methods such as level sets, watersheds and region growing.
>>>
>>>
>>>
>>> That being said...
>>> We should first take a look at your images. Maybe the factors
>>> that you describe are not as accentuated as we are assuming
>>> here.
>>>
>>>
>>>
>>>     Regards,
>>>
>>>
>>>
>>>         Luis
>>>
>>>
>>> ------------------------
>>> Emiliano Beronich wrote:
>>>
>>>> Hello,
>>>>
>>>> I write in regard to a technical problem with segmenting kidneys 
>>>> from gamma cammera images. I am basically trying to segment a kidney 
>>>> and I am facing problems such as different intensity regions between 
>>>> right and left kidney, irregularities inside the kidney region and 
>>>> diffuse edge of the region by a slow trasition.
>>>> I would like to know which strategy is recommended to deal with 
>>>> these issues and which algorithm you consider better for this 
>>>> application.
>>>>
>>>>
>>>> Regards,
>>>>
>>>>     Emiliano
>>>> _______________________________________________
>>>> Insight-users mailing list
>>>> Insight-users at itk.org
>>>> http://www.itk.org/mailman/listinfo/insight-users
>>>>
>>>>
>>>
>>>
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> 
> 


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