[Insight-developers] Re: [Insight-users] load a CT scan (DICO M)

[Stephen R. Aylward]

Hi,

I guess we never intended to support all of dicom.  We opted to not 
require the users to install another library to make itk work and so we 
implemented a subset.   Perhaps we chose poorly on the subset, but with 
over 700 tags in dicom....I am happy with what we have chosen.   I think 
the code supports extension quite nicely too.   The IO factory is really 
easy to use to add other types as well (thanks Will!).

Also - the metaImage reader doesn't use the dicomIO methods - it just 
skips the dicom header and reads the data according to the description 
file (i.e., the metaheader).

Thanks,
Stephen


Miller, James V (Research) wrote:
> What?
> 
> Where does the MetaImageIO delegate to the DicomImageIO?  I do not see any
> references to the DicomImageIO in the MetaImageIO class.
> 
> If the MetaImageIO delegates to the DicomImageIO, then why do we need 
> (all the information) in the MetaImageIO headers?  All of that information
> is in the DICOM file.
> 
> Jim
> 
> 
>>-----Original Message-----
>>From: Luis Ibanez [mailto:luis.ibanez@kitware.com]
>>Sent: Monday, September 16, 2002 12:43 PM
>>To: Miller, James V (Research)
>>Cc: Stephen R. Aylward; Insight-developers (E-mail)
>>Subject: Re: [Insight-developers] Re: [Insight-users] load a CT scan
>>(DICOM)
>>
>>
>>
>>Hi Jim,
>>
>>The MetaImage reader delegates the reading of every slice to the
>>Dicom reader (Insight/Code/IO/DicomImageIO).
>>
>>Support for Dicom features is not built-in into the MetaImageIO
>>reader but into DicomImageIO.
>>
>>The "intensity offset" is not implemented in the current reader.
>>If it is added that will be done in the DicomImageIO class.
>>
>>
>>Luis
>>
>>
>>================================================================
>>
>>
>>Miller, James V (Research) wrote:
>>
>>
>>>Can the MetaImage format handle the "intensity offset" that can be
>>>encoded in DICOM images?
>>>
>>>For instance, signed data with a known range that is stored 
>>
>>as unsigned data 
>>
>>>(so you need to apply additive offset).
>>>
>>>
>>>
>>>
>>>
>>>
>>>>-----Original Message-----
>>>>From: Luis Ibanez [mailto:luis.ibanez@kitware.com]
>>>>Sent: Friday, September 13, 2002 5:09 PM
>>>>To: Miller, James V (Research)
>>>>Cc: Stephen R. Aylward; Insight-developers (E-mail)
>>>>Subject: Re: [Insight-developers] Re: [Insight-users] load a CT scan
>>>>(DICOM)
>>>>
>>>>
>>>>
>>>>Hi Jim,
>>>>
>>>>The MetaImage format just requires to create a header text file that
>>>>points to the original DICOM data. For example, I'm using the 
>>>>following
>>>>MetaImage header file to read directly a set of Dicom files. No data
>>>>is duplicated in this approach.
>>>>
>>>>  NDims = 3
>>>>  DimSize = 512 512 41
>>>>  Position = 0 0 0
>>>>  ElementSpacing = 0.63281 0.63281 7.0
>>>>  ElementByteOrderMSB = False
>>>>  ElementType = MET_USHORT
>>>>  HeaderSize = -1
>>>>  ElementDataFile = image%04d.dcm 1 41 1
>>>>
>>>>
>>>>---(this header file is also attached to this message)----
>>>>
>>>>This reads the following files into a 3D image:
>>>>
>>>>  image0001.dcm
>>>>  image0002.dcm
>>>>  image0003.dcm
>>>>  image0004.dcm
>>>>  ...etc
>>>>  image0041.dcm
>>>>
>>>>The header file was created with the MetaImageImporter but it could
>>>>have been created by hand once you know the fields that are 
>>>
>>required.
>>
>>>>
>>>>  Luis
>>>>
>>>
>>


-- 
===============================================
Dr. Stephen R. Aylward
Assistant Professor of Radiology
Adjunct Assistant Professor of Computer Science
http://caddlab.rad.unc.edu
aylward@unc.edu
(919) 966-9695