General-DICOM

Dicom Query Date/Time range

Format allowed in specifying the Date/Time range in Query:

 

  • "YYYYMMDD-YYYYMMDD"
  • "YYYYMMDD-"
  • "-YYYYMMDD"
  • "HHMMSS-HHMMSS"
  • "HHMMSS-"
  • "-HHMMSS "

 

What do you get with combined date time range:

 

For example:

Date Range, for example "01/10/2011 - 02/10/2011"

Time Range, for example "090000 - 100000"

 

Image Box

There are two sorts of Image Box objects used in Printing:

Configuring Namespace Reservations

Due to the increased security in Windows 7 and Vista if you require a portion of the HTTP URL namespace (i.e. http://+:80/MyPortion) Then It must be assign by an administrator from the command line. This is of particular importance to those implementing Jpip or Wado servers.

The Command to assign the http portion is

netsh http add urlacl url=http://+:80/MyUri user=DOMAIN\user

For more details please see the MSDN page

DICOM Router/Gateway Workflow

Very often questions are asked about DICOM Router/Gateway implementations. So this is a summary of the options.

DICOM Sequences

DICOM allows a dataset to contain other nested datasets, which are encoded as "sequences". The point of this structure is to allow repeating groups of data, so whilst such sequences often only contain a single dataset, the format is defined such that each sequence consists of a set of datasets. Of course, this structure lends itself perfectly to recursion, and some DICOM IODs such a Structured_Reporting and the Radiotherapy_Extensions can use sequences nested 5 or 6 deep !

Meta SOP Class

A Meta SOP class is used where it is required to negotiate a "set" of SOP_Classes as a batch, as one would not be useful without the others. The Meta SOP classes still used in DICOM are:

SOP Class

SOP class is one of those horrible obscure expressions used in DICOM which put people off the standard immediately! It is supposed to stand for "Service Object Pair", and has its roots in the slightly odd object orientated origins of DICOM, but in practice, each object only has one directly associated service (Storage) and each other service only has one type of object, so a better name would be:

Service OR Object

So in reality there are 2 sorts of SOP classes:

Lookup Tables

There are 4 types of lookup table (LUT) which can be found within DICOM images are part of the standard, and one further type which exists in DicomObjects. 

Palette Colour LUTs

These are only used when the Photometric_Interpretation is PALETTE COLOUR. They can be 8 or 16 bit, and 3 copies exist, one each for red, blue and green.

Secure Connection with DVT Simulator

If you are testing DicomObjects's Secure Connection Functionalities and wish you to use DVT simulator as the tester, then it is very easy to do so as long as you have the DVT-trusted ".p12" file (we are using the one that comes with DVT here):

Dim sec As New DicomServerSecurity
Dim CertBytes As Byte() 
CertBytes = System.IO.File.ReadAllBytes("C:\Program Files\DVT\certificates\SutSelfSigned.p12")
sec.Certificate = New X509Certificate2(CertBytes, "dvt")
sec.ClientAuthentication = False
server.Listen(104, sec)  ' server is a DicomServer object

TCP limitations in DICOM

DICOM uses TCP (transmission control protocol) as its underlying network transport layer, and despite its widespread and generally successful use around the world for most Internet use, TCP does have some significant limitations. In practice, these limitations are extremely rarely encountered in real life, but they can sometimes be seen in stress test scenarios, and it is then important to to be able to distinguish between those failures which are due to the DICOM application being tested, and those which are intrinsic to TCP itself.

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