1. Dosis “Data Mining”
Paul W. de Bruin
klinisch fysicus radiologie i.o.
Afdeling Radiologie
Leids Universitair Medisch Centrum
2. The Ideal World
1. Dose data is available at the scanner after a scan
2. Dose data is stored in an archive
3. Statistics on dose data can be calculated (“data mining”)
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3. Californian Senate Bill no. 1237
• 115111. (a) Commencing July 1, 2012, subject to subdivision (e), a person that uses
a computed tomography (CT) X-ray system for human use shall record the dose of
radiation on every CT study produced during a CT examination.
• (b) The facility conducting the study shall electronically send each CT study and
protocol page that lists the technical factors and dose of radiation to the electronic
picture archiving and communications system.
• (c) The displayed dose shall be verified annually by a medical physicist to ensure the
displayed doses are within 20 percent of the true measured dose measured in
accordance with subdivision (f) unless the facility is accredited.
• (d) Subject to subdivision(e), the radiology report of a CTstudy shall include the dose
of radiation by either recording the dose within the patient’s radiology report or
attaching the protocol page that includes the dose of radiation to the radiology report.
• (e) The requirements of this section shall be limited to CT systems capable of
calculating and displaying the dose.
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4. DICOM/RIS/PACS/ZIS/EPD?
• DICOM: Digital Imaging and Communications in Medicine
• http://medical.nema.org
• Data structures (patients, images, reports)
• Services (storage, query, retrieval, transfer of data)
• PACS: Picture Archiving and Communication System
• Data archive
• IHE: Integrating the Healthcare Enterprise
• Workflow definition for modalities and PACS
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9. How to get dose information
• Basic DICOM
• DICOM SR (Structured Report)
• Dose reports stored as “screen saves”
• Use DICOM MPPS
• Query PACS
• IHE REM: defines workflow
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10. DICOM Structured Report
• DICOM Class
• A “databaseable document” format linked with image data
• computer search analysis
• research
• education
• clinical trials
• data mining
• Templates Working Groups
• DICOM Dose SR
• Supplement 127: CT Radiation Dose Reporting (Dose SR)
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11. DICOM Structured Report – example text dump
(0008,0100) SH [CODE_12] # 8, 1 CodeValue
(0008,0102) SH [99_OFFIS_DCMTK] # 14, 1 CodingSchemeDesignator
(0008,0104) LO [Illnesses] # 10, 1 CodeMeaning
(fffe,e00d) na (ItemDelimitationItem) # 0, 0 ItemDelimitationItem
(fffe,e0dd) na (SequenceDelimitationItem) # 0, 0 SequenceDelimitationItem
(0040,a160) UT [The patient had polio at age 8, from which she made a remarkable r... # 206, 1 TextValue
(fffe,e00d) na (ItemDelimitationItem) # 0, 0 ItemDelimitationItem
(fffe,e000) na (Item with undefined length #=4) # u/l, 1 Item
(0040,a010) CS [CONTAINS] # 8, 1 RelationshipType
(0040,a040) CS [TEXT] # 4, 1 ValueType
(0040,a043) SQ (Sequence with undefined length #=1) # u/l, 1 ConceptNameCodeSequence
(fffe,e000) na (Item with undefined length #=3) # u/l, 1 Item
(0008,0100) SH [CODE_13] # 8, 1 CodeValue
(0008,0102) SH [99_OFFIS_DCMTK] # 14, 1 CodingSchemeDesignator
(0008,0104) LO [Allergies] # 10, 1 CodeMeaning
(fffe,e00d) na (ItemDelimitationItem) # 0, 0 ItemDelimitationItem
(fffe,e0dd) na (SequenceDelimitationItem) # 0, 0 SequenceDelimitationItem
(0040,a160) UT [ALLERGIC TO PENICILLIN. She denies any other drug or food allergies.] # 68, 1 TextValue
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12. DICOM Structured Report - Example
“The finding is a mass
measuring 1.3 cm in
diameter with an infiltrative
margination.
The conclusion is a
probable malignancy,
inferred from the infiltrative
margination of the mass.”
Hussein et al. DICOM structured reporting: Part 1. Overview and characteristics. Radiographics : a review publication of the
Radiological Society of North America, Inc (2004) vol. 24 (3) pp. 891-6
David A. Clunie, DICOM Structured Reporting, ISBN 0-9701369-0-0, out of print. PDF at: http://www.pixelmed.com/srbook.html
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19. Query the PACS
1. Via vendor interface
2. Using the DICOM interface
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20. DICOM Patient-Study-Series-Image Model
Patient Study Series Image
PA
Jansen CT Onderzoek Scout LR
Image 1
Anatomische scan
Image …
Image 200
Contrast Image 1
Image …
Image 600
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21. Work flow
• Query PACS for studies on a date
• For each study query PACS for
series (filter on CT/DX/MAMMO)
• For each series query PACS for
images
• Retrieve each image
• Throw away image data
• Store dose information in local
database
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22. Why so complicated?
• Patient-Study-Series-Image is dictated by DICOM
• Attributes are defined at different levels:
• Modality is defined at Series level.
• Dose information is defined at Image level.
• No support for optimized generic batch retrieval.
• PACS has limit on number of query results
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23. CT Dose from DICOM Images
García et al. Automated effective dose estimation in CT. Radiat Prot Dosimetry (2010) vol. 138 (1) pp. 71-7
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24. CT Dose from DICOM Images
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26. Concluding
Storage Data Mining/Retrieval
•Basic DICOM •Query PACS
• Standard dose parameters
• Using PACS functionality provided by
• Basic modality support
vendor
•DICOM SR (Structured Report)
• rare
• Not implemented (yet) by most vendors
• “Best solution” • Using DICOM interface
•Dose reports stored as “screen saves” • Generic
• Better than nothing or manual lists • Brute-force
• Implemented by most vendors • Slow
• Can be converted to DICOM SR • Generic
•DICOM MPPS
• Can only retrieve what is in the
• Dose information via messages,
PACS
messages are not stored
• Cannot go back in PACS history
• Commercial third-party solution
available
•Generic
• History?
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