A well defined and managed network infrastructure is essential. Dynamic IP addressing is fine as long as the router does not re-assign them to a different address, e.g. when being re-booted or replaced. A rather frequent occurrence is the incorrect setting of the switch, e.g. to half duplex or mismatching the device setting, especially when auto-negotiating is configured. Switch issues result in major performance issues and can only be made visible when using a network sniffer. Combined with ’netscan’ utilities to detect any IP addressing issues, these are essential tools to deal with these issues.
2. DICOM Header Issues:
The DICOM image header is generated through mapping RIS data, generation by a modality and manual input by a user. Either one of these sources can potentially generate incorrect and/or invalid data in the image header. Problems are unfortunately not always immediately detected. For example, an incorrectly identified study might be archived in the PACS and get “lost,” only appearing when the data is migrated, which could be years later. A header with an Institution ID exceeding the maximum length of that field might be stored by vendor A while being rejected by vendor B as an invalid image when being migrated years later. Keeping tight tabs on these issues and validate images using appropriate tools is important.
3. Hanging Protocol Issues:
Hanging protocols not working is almost always related to incorrect header information or the wrong interpretation of the headers. A common mismatch is related to the way CR and DR systems organize their images into series. Some create a new series for each view (e.g. a Chest PA and LAT), some group them together in a single series. Another frequent issue occurs when some modalities modify automatically series and study descriptions, not taking the values from the worklist and therefore causing these descriptions not matching the hanging protocol configurations at the view station. Sometimes, additional QA steps are required, in addition to training of technologists.
4. CD import issues:
These issues almost always can be traced back to non-compliance with the DICOM standard and/or corresponding IHE profile. Frequent issues are the absence of DICOM image files because the vendor is only providing their proprietary format, a missing directory file, mismatch of the so-called meta-file header with the actual data content, incorrect transfer syntaxes such as compression, and several others. In many cases, one can convert the images to an acceptable format that can be imported using additional tools; however, in some cases it is impossible to read the proprietary information, causing a repeat exam.
5. SOP Class support:
Modalities are eager to support new functionality, represented by the use of new SOP Classes as they contain more information and allow for better viewing and processing. The most common mismatches are due to non-support of the PACS for the enhanced CT, MRI SOP Classes and Structured reports, such as generated by CAD devices and Ultrasound units for measurements. In most cases, a modality can be “de-featured” to fall back to an older SOP Class, or alternate encoding (e.g. burn in the CAD marks into a secondary capture), in some cases, one will be stuck with the proprietary information (e.g. MRI spectroscopy).
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