Mammography Techniques and Positioning Tips for Improved Image Quality

Welcome the eLearning Mammography Techniques and Positioning Tips for Improved Image Quality. This course will review what takes place to image transfer behind the scenes.   This course was developed through a collaborative effort by: Karen DeVoid RT (R)(M)(CPAS) Clinical Education Specialist Siemens Healthcare Dave Randolph Senior Technical Instructor Siemens Healthcare   At the end of this session, the technologist will be familiar with: ACR Guidelines Technical Factors Identify Artifacts Troubleshoot Corrective Action Common Error Codes MLO Views CC Views ML Views   Mammogram Patient Technique System Incorrect positioning is the most common problem when evaluating images Better understanding of the anatomy and mobility of the breast Mobile borders of the breast are inferior and lateral Needs to be tailored to the individual patient’s habitus Utilizing the versatility of the Novation to obtain desired image Visualize the maximum amount of breast tissue in one view   Visualization of retro-mammary fat   Angle from 30-60 degrees so detector is parallel to pectoralis muscle   Pectoralis is convex and extends to or below the nipple line   Maneuver breast up and out to avoid camel nose or drooping of the breast   IMF is open, no skin folds or other artifacts This image does not display acceptable positioning artifact in axilla (skin fold)   pectoralis muscle does not extend to the nipple line   camel nose (drooping)   no IMF Possible solutions reduce the angle   lower the detector   use the up and out maneuver   have patient lean into detector Done to ensure that any tissue missed on the MLO is visualized   All medial tissue should be included   Nipple in profile and centered on image   Posterior nipple line measures within 1 cm of the MLO or visualization of the pectoralis muscle   No skin folds or other artifacts This image does not display acceptable positioning artifact in lateral aspect of image   nipple is not in profile   questionable if all breast tissue is included Possible solutions elevate the IMF   have patient pull back on shoulder   pull breast tissue onto detector; do not place it   do nipple in profile view if necessary Most common additional view   Used to triangulate location of lesion   Used to determine milk of calcium   Use the up and out maneuver   Make sure the IMF is open Done in quadrants   Overlap quadrants to make sure all tissue is imaged   Leave portion of detector uncovered Poor positioning may lead to unwanted artifacts on your image   Skin folds   Other body parts   IMF not properly visualized/abdominal fold   Improper positioning with the SpotPlus Paddle Keep shoulders, chin, and head out of image   Can cause incorrect image processing   By window/leveling you can see that there is an image there, however, you lose information and limit the latitude the radiologist has to view the image   Spot compression views   Highlights region of interest   No loss of landmarks   Compress to at least the depth of the indentation   Patient Technical Factors Items to consider: kVp   mAs   compression force   thickness   target/filter   glandular dose The F max knob is located on the front of the compression unit at the top   Should be set to 20; however, some states stipulate max should be 18 The actual readout is at the bottom of the stand at the floor   Continually depress the foot peddle Senses optimum amount of compression based on breast thickness   Will stop automatically and green light will appear on bottom left of stand   The detector sends information to the system based on the initial 5 mAs exposure   The Auto button must be activated in order to function   Auto button is located to the right of the Opdose program buttons   Receives information from the Opcomp feature and the detector   Will flash green to indicate appropriate technique   Radiation Dose “The average glandular dose delivered by a single craniocaudal view of a 4.2-cm thick, compressed breast consisting of 50% glandular and 50% adipose tissue must not exceed 0.3 rad (3.0 milligray), although it is generally much lower. This applies to both screen-film and full-field digital mammography.” Patient Technical Factors System Mechanical Detector Miscellaneous Mechanical Artifacts Filter Wheel   Grid   Paddle   Collimator Filter Wheel Background appears crooked   Filter wheel did not reach the correct position   Place service call to have filter wheel adjusted Grid Lines Seen as faint, thin, evenly spaced lines throughout the image Enhanced when windowing image   Place service call to have filter wheel adjusted Grid Lines Appearance of grid lines After adjustment of grid Compression Paddle White border on patient side  with rounded edge If just one paddle affected, adjust the paddle   If all paddles are affected, place service call, compression unit needs to be adjusted Collimator White, sharp, limited stripe border   Place service call, collimator needs to be adjusted   Detector Artifacts include: Microphony   Bad Pixel or Bad Cluster   Bad line or Bad Quadrant   Crystallization and Delamination   Scrambled Image Microphony Lines that appear only in image   Due to movement of the detector during image acquisition   Reacquire the image   Wait for arrow before moving detector Bad Pixel/Bad Cluster Bad pixel size is 70 microns Difficult to visualize   Bad cluster is 3x3 pixels Easier to visualize Bad Pixel/Bad Cluster Perform gain calibration   If not corrected, place service call   Service will do a bad pixel map   If not corrected, may have to replace detector   Crystallization Noticed in gain calibration image   Most cases give blurry impression on the detector border sides   Place a service call assure crystallization possibly replace detector Delamination Appearance of watermarks throughout image   Only visible on phantom images, not patient images   Delamination of the detector Place a service call, the detector will be replaced   Bad Quadrant One quarter of the detector is not displaying data   Place service call No repair possible Replace detector Ghosting Shadow of object remains visible   in following exposure. Can be caused by: High dose, detector remains saturated during second exposure   Detector temperature incorrect   Adjust technique   Verify room and detector temperature Halo Effect Halo effect around the breast tissue   Usually seen on very small or very large breasts   Visible under windowing   Seen on high mAs techniques   Increase your kVp, keeping the mAs down   **Does not affect image quality of breast tissue**   Anode Heel Effect Will appear as a half-moon shape on the stand side of the detector   More visible with W/RH than Mo/Mo   Does not affect the image quality Scrambled Image Portion of the image is cut-off and appears at a different area on the detector   Very rare, due to a software error in  the detector   Will usually occur right after start-up Restart the system to correct Bad Lines Closely spaced lines in image   Not throughout entire image like grid line   Place service call   Will try pixel mapping   May need to replace detector Bad Line throughout Image Lines appear in complete image   Along the camera segments   Infrequent A restart of system will usually correct   Common Error Codes 004 AEC not ready 005  AEC not correctly initiated 008  Emergency stop button depressed 011  Exposure aborted by user 012  Time limit reached 013   mAs limit reached 014  Not enough kV 040   Room door is open (if this function is engaged) Common Error Codes 401/402/403 AEC switched off 404  Not enough power to penetrate, increase kVp 405  AEC in process of self-test, retry exposure 407/408 Timed out error, switch machine off for 1 minute 410  AEC not ready, retry exposure 413   Change exposure parameters, lower kVp 450   Exposure aborted, increase kVp Common Error Codes 504  Error within Novation, usually released the exposure too soon 578  mAs exceeds maximum 777  Opdima time out error (over 60 seconds to make exposure) 801  Grid did not reach start position, retry exposure 831  Paddle decoder communication error, clean sensor Patient Technical Factors System Dave Randolph Senior Technical Instructor   In this lesson, we will: Define IHE   Define HL7   Define DICOM   Explore DICOM processes   Discuss DICOM configuration   Show IHE workflow in detail   Show DICOM workflow in the mammography department First, let’s start with some preliminary information we will need to help us understand DICOM workflow.   Stands for Integrating the Healthcare Enterprise   Initiative by healthcare professionals and the healthcare industry to improve the way healthcare systems share information   IHE does not create standards but defines how the standards should be used by establishing profiles   IHE profiles provide precise definitions of how standards can be implemented to meet clinical needs HL7, which is an abbreviation of Health Level Seven, is a standard for exchanging information between medical applications. This standard defines a format for the transmission of health-related information   Health Level Seven International is a standards organization that was established in 1987 to create a standard protocol for the exchange, integration, sharing, and retrieval of electronic health information   Health Level Seven’s domain is clinical and administrative data. It handles information not specific to medical imaging   HL7 messages are in human-readable (ASCII) format as in this example: MSH|^~\&|Sys|Hosp|HL7Connect|Hosp|20020313173613||ADT^A01^ADT_A01|0000000403|P|2.3.1 EVN|A01|20020313173614149|||a017 PID|||875665^^^PH||NGO^LISA^^^Ms||19750514|F|||101 COLS STREET^^MELBOURNE^VIC^3000 PV1||I|3S^13^1^^^^^^Ward 3 Wouth||||TESTDR^TEST^JOHN^^^DR|||ORT|||||||||15521|COM| Digital Imaging and Communications in Medicine   Formerly known as ACR-NEMA 1 & 2 (American College of Radiology-National Electrical Manufacturers Association)   Standard established for the medical industry to define the handling, storing, printing, and transmission of information in medical imaging   DICOM implementation is specified by vendor in a conformance statement DICOM is the main topic of this presentation User SCU Provider SCP Database request response make transfer acknowledge The Service Class User (SCU) requests a service from a Service Class Provider (SCP) The Provider responds with an “accept” or “reject” If the provider has accepted the request, then the SCU sends the object to the SCP and the SCP performs the service Host Name — the name given to the hosts participating in the DICOM session   IP Address — the address assigned to the hosts participating in the DICOM session   Application Entity Title — name of the service provided by the Service Class Provider (SCP)   Port Number — number of the input port the service will be handled through Open Association Message Exchange Close Association A-Associate - RQ A-Associate - RSP DICOM Message - RQ DICOM Message - RSP A_Release-RQ A-Release-RSP Archive Modality SCU SCP Open Association (association negotiation DICOM Message Exchange   Close (release) Association HL7 Examination Order Procedure Scheduled Patient Information DICOM Status Report Film Folder Image Retrieve Acquisition Completed Storage Storage Commitment Image Print Modality Worklist Performed Procedure Steps Litebox PACS Archive Printer Modality RIS HIS ADT Report Repository Now let’s look at what is defined for the clinical workflow according to the IHE guidelines. 1 2 3 4 5 6 7 8 9 10 RIS Mammomat Novation MammoReport PACS Printer CAD Modality Worklist (MWL) Modality Performed Procedure Step (MPPS) Send/StC Print Send/StC Send SR Query/ Retrieve IHE stands for Integrating the Healthcare Enterprise and establishes profiles to define processes in the medical industry.   HL7 is a protocol used to transfer medical information between medical information systems.   DICOM stands for Digital Imaging and Communications in Medicine and is a protocol used to transfer, store, and print medical images.   DICOM partners have two roles: Service class user (SCU) Service class provider (SCP)   There are three parts to any DICOM session: Association/Negotiation Message Exchange Association Close IHE workflow has become the industry guideline through the use of profiles. DICOM services used in mammography workflow consist of: storage storage commitment query/retrieve modality worklist modality performed procedure step basic grayscale print