MAMMOMAT Revelation and MAMMOMAT Inspiration Tomosynthesis Training for Medical Physicists

MAMMOMAT Revelation and MAMMOMAT Inspiration Tomosynthesis Training for Medical Physicists By the end of this course the learner will be able to: Define Tomosynthesis and the risks vs. benefits. Identify the system specifications needed to perform tomosynthesis. Differentiate between image acquisition parameters. Utilize post-processing tools to optimize image impression. Differentiate between 2D and 3D image acquisitions. Identify the necessary reconstruction for breast type. List the quality control physicist requirements for tomosynthesis. Review quality control requirements for the technologist.   Tomosynthesis Essentials   Digital Breast Tomosynthesis (DBT) is a three-dimensional imaging technique which provides an arbitrary set of reconstruction planes in the breast from a limited angle series of projection images acquired while the X-ray tube moves through an arc above the stationary detector. The result is a 3D data set of the entire breast volume. The individual “planes of interest” of a chosen slice separation/slice distance can be viewed separately from the rest of the image.     False Negative: 15-30% of cancers missed Lesions are not perceived Abnormalities are misinterpreted False Positive: increase recall rates Due to Dense breast tissue-anatomical noise 3D information projected in a 2D image plane (tissue overlap)     Projection - Single image taken during the tomo scan. Projection Angle - The projection angles are defined as the angle of the tube head during the tomo sweep relative to the 0° position. Projections Raw - Projections acquired during a tomo acquisition, unprocessed. Projections Processed - Projections acquired during a tomo acquisition and processed for better visualization. Depth Resolution - Resolution in the Z-direction. It gives a measure how two points can be separated in the Z-direction. Depth resolution is typically a few millimeters, depending on the size of the object, the reconstruction algorithm and scan angle. In-plane Resolution - Resolution in the slice in x- and y-direction. It depends on the reconstruction algorithm. Slices - Stack of images parallel to the detector surface reconstructed from projections with the purpose of display at the workstation monitor. Slice Separation - Distance between two slices.  Generally the volume is displayed in a 1 mm slice separation. Slice Thickness - Vertical (Z-direction) spatial extent of one slice. Because tomosynthesis data acquisition is incomplete (limited angle) the slice thickness is much larger than the in-plane resolution. This means close features cannot be well resolved in Z-direction and extend over several reconstructed Slices. Filtered Backprojection - Reconstruction algorithm, mostly used in tomographic imaging. The measured projections are filtered and then - taking into account the acquisition geometry -backprojected into the volume providing a 3D data set. The filtering includes noise regularization and can help to define the physical slice width. To examine the basic principles of tomosynthesis, click the tabs below. 2 dimensional projection showing a mass of indeterminate exact location 2 dimensional projection showing a mass of indeterminate exact location Information for the mass (represented by the blue circle) from three different projections is added. Reconstructing multiple slices, yields a 3D image of the studied object. In this illustration, the slice where the red dot located is reconstructed.   In this example, the shifting and adding of the 3 images enables the localization of the two masses along the z-axis. Three Slices (green red and purple) perpendicular to the z-axis are reconstructed, each with accurate spatial information.     The Challenge: To achieve an image quality that will render maximum clinical benefits with a limited radiation dose. Image Quality Paramenters: Quality of each projection Number of projections Angular range of the projections Image reconstruction algorithm   X-ray generator: Power output : 5kW X-ray tube unit: Tungsten (W) anode with 0.3mm focus Rhodium (Rh) filter Flat detector: Solid-state detector amorphous selenium (aSe) Detector size: 24cm x 30cm Pixel size: 85 µm Image matrix: 2816 x 3584 (24cm x 30cm)     Larger angular range will better separate objects from different depth; but may reduce the accessible volume that can be imaged. Fewer projections render less information and may cause streak artifacts; more projections leads to more radiation.     Siemens uses an angle of 50 degree 25 projections Acquired at 20 intervals Covers 200mm wide 80mm thick If breast compresses to above 80mm there will be a few projections that do not include data from 100% of the breast.     Ramp type filter compensates blurring   Spectral filter reduces high frequency noise Slice thickness filter ensures constant depth resolution 3D tomosynthesis 2D mammography Ductal carcinoma in situ with irregular microcalcifications, negative lymph nodes. Morphology of microcalc is better seen in 2D mammography, the ductal pattern of the calcification is more obvious in 3D tomosynthesis. Image courtesy of KU Leuven, Belgium, Prof. van Ongeval and Dr. van Steen   3D tomosynthesis 2D mammography 2.8 cm, grade 3, invasive ductal carcinoma in the right breast imaged with digital mammography and breast tomosynthesis. The MLO digital mammography view shows dense breast tissue with subtle distortion in the lower breast. The MLO tomosynthesis slice shows a spiculated mass in the lower breast to be much more evident than in the corresponding mammogram.   0.9mm intraductal carcinoma, invasive growing BIRADS 5, density ACR b. The tumor is better evaluated in tomosynthesis. Image courtesy of KU Leuven, Belgium, Prof. van Ongeval and Dr. van Steen 3D tomosynthesis 2D mammography 1.5 cm invasively growing carcinoma, mixed with 2 cm DCIS. The lesion and its delineation are better visible in the tomosynthesis image. The fact that microcalcifications are positioned in the neighbourhood of the tumour suggests a DCIS component. Image courtesy of KU Leuven, Belgium, Prof. van Ongeval and Dr. van Steen 3D tomosynthesis 2D mammography 0.9 mm intraductal invasively growing carcinoma, BIRADS 5, with a density of ACR B. Tumor evaluation is better with tomosynthesis than with DM. Image courtesy of MVZ Prof. Dr. Uhlenbrock & Partner, Prof. Dr. Detlev Uhlenbrock         Tomosynthesis Applications and Workflow    With tomosynthesis, three-dimensional information can be obtained by taking exposures from different angles. This significantly reduces the tissue overlap problem which limits diagnosis in conventional mammography. Tomosynthesis is displayed and controlled at the workstation. In tomosynthesis, the X-ray tube rotates in a defined angular range. During the acquisition, several X-rays are taken from different directions. Each of these single exposures is taken with a very low dose. Due to the different acquisition directions, the set of 2-dimensional X-ray images contains the 3D information of the object, allowing the volume of the breast to be reconstructed by appropriate software algorithms and visualized in the form of slice images. During tomosynthesis acquisition, the swivel arm of the MAMMOMAT Revelation and MAMMOMAT Inspiration covers an angular range from +25° to -25° while 25 views are acquired.  25 views are acquired in an angular range from -25° to +25°. The exposure release button on the control box or on the foot or hand switch must be pressed and held during all exposures.  The procedure happens as follows: The swivel arm is in the 0° position. The first view is acquired for automatic exposure control. The swivel arm moves to -25°, the second exposure is taken. The swivel arm covers the entire angular range from -25° to +25° while an exposure is taken at every 2°. The swivel arm returns to the start position. The exposure release button is released. The first view is displayed. The slices are automatically reconstructed and then displayed. The projections are processed and displayed The following compression plates can be used for a tomo examination:   26 cm x 35 cm compression plate (2) 24 cm x 30 cm Low compression plate (2)  A special face shield must be used during tomo examinations (1)     The processing starts immediately after the acquisition with the default Reconstruction Parameter Group (RPG). The status is displayed on the bottom of the screen, and shows the progress of the reconstruction of slices and the projection processing. When calculating the projections, the initial acquisition is included so that 26 projections are processed. When all 26 slices/projection views have been generated, the view changes to the Tomo subtask card.   Tomo examination images can be processed in the Tomo subtask card in the Examination  task card.    First View: exposure taken at an angle of 0° Projection View: 25 views are processed from different angles from which the slices are reconstructed. Note that the acquisitions were taken with a low dose and restricted image quality.  Slice View:  Shows images of reconstructed slices (3D volumes) from which projections of different reconstruction algorithms (RPG) are possible. Bounding Box defines the volume for the calculation of the slices and should always cover the whole breast. It can be adjusted to include or exclude tissue, i.e., the abdomen. Acquisition parameters and dose information are displayed on the lower left corner of the image area. 26 projections taken at the different angles from which the slices are reconstructed. Taken with low dose and restricted image quality. Not to be used to perform clinical measurements.  The stack of images parallel to the detector that are reconstructed from raw projections.   Automatically reconstructed and displayed based on default RPG.   Number of slices depends on the compression thickness, compression plate and compression force.   Not to be used for clinical measurements. For better visualization of details, tomo images can be reconstructed with different reconstruction parameters. You can: Click the Reconstruct... button (1). Or Right-click on the Reconstruct Tomo Scan icon in the Images Subtask Card and select Recontruct Tomo Scan (2). Or Right-click in the image.  Select Recontruct Tomo Scan (3) from the dialog box displayed. Using any of these methods launches the Reconstruction of Scan dialog box. Select a reconstruction parameter from the Reconstruction parameter group name list - Standard, Calcification or Phantom. Note that you have to disable the following projection before you can start the reprocessing.   Abnormalities in the images are generally easier to detect if you view the images in quick succession like a movie. The Tomo subtask card provides a function for fast, automatic scrolling through the images of a either a projection view or slice series. To view this, click the Movie Properties button (1) on the Tomo subtask card. Movie Properties subtask card: Exclude irrelevant first/last images (2) Pause and restart the movie (3) Change the playback speed and direction (4) Deselect the Yoyo option to play the movie in a loop (5). You can delete reconstructed images using the pop-up menu or the Delete Reconstruction button. Click the Slices button in the Tomo subtask card(1). The slice views are displayed.  Select the image you want to delete. Click the Delete Reconstruction button (2). Or Right- click on the image. Select Delete Reconstruction (3) in the popup menu that appears.   Using any of these methods launches the Reconstruction of Scan dialog box. Click Yes to make the changes. The stored series with the selected reconstruction parameter in the Patient Browser are deleted. Click No if you don't want to make the changes.   To end the examination, click the End Examination button in the Close Patient  subtask card.  As soon as you have generated more than 3 series with the reconstruction parameters, the message window shown will appear before you can close the Examination. Click Yes to save all series Click No to switch to the Tomo subtask card 2D View Tomo 3D View 2D + Tomo 3D View The 2D + Tomo-Scan function produces a conventional 2D exposure and a complete tomo scan during an exposure. Before the start of the examination: from the main menu select Options > 2D + Tomo-Scan.   Double-click the 2D + 3D Exposures button The detector parameters are loaded and the following exposures are created: Pre-shot 2D exposure (single image) 25 Projections   First View is a normal 2D image and can be used for the diagnostic purpose. Dose displayed in First View is the dose of 2D exposure.   Slice view for 2D+3D scan. Dose displayed in Slice View is the dose of 3D exposure.   You can create additional examination procedures and revise or delete existing procedures with the Procedures tab card. Procedures provided as factory defaults are listed here. You can use these procedures immediately for your examinations or use them as a template for additional new procedures you create. Factory default Procedures   Recon Parameters You can select the reconstruction parameters configured by the service engineer. (standard, calcification or phantom). Additional reconstruction parameters can be configured by service engineer upon request. In the WH AWS Transfer Configuration dialog you define which image material from the examination should be transmitted automatically to the individual destination addresses. You differentiate in this case according to image type and examination purpose of the images.   Selection overview: Single Images for processing - individual raw data suitable for image processing or CAD server.  Corresponds to 2D images. Single Images for presentation - individual processed images, suitable for reporting station. Corresponds to 2D images. First View for processing  - raw data of the first exposure or 2D exposure, suitable for the special 2D + Tomo-Scan mode. First View for presentation - processed images of the first exposure or 2D exposure, suitable for the special 2D + Tomo-Scan  mode. Tomo projections for processing - raw data set of the 25 projections. Tomo projections for presentation - processed data set of the 25 projections. Slices for presentation - reconstructed slices, suitable for the reporting station. Tomosynthesis Quality Control     Mammography Equipment Evaluation (MEE) – Medical Physicist (MP) New Install After disassembled and reassembled After major components change or repair Annual Tests – Medical Physicist (MP) Comparison to values measured during MEE tests. Monthly Tests – Technologist (T) Tests performed on monthly basis by technologist. "When Needed" Tests – Technologist (T) Whenever there is suspicion of artifact or incorrect settings A detailed report of a mammography equipment evaluation must be completed within 6 months prior to the request for a facility certificate extension. To review some key quality control measures for the MAMMOMAT Revelation or MAMMOMAT Inspiration system, rollover the highlighted areas in the chart below.   The required quality control tests are described in both the MAMMOMAT Revelation and MAMMOMAT Inspiration Tomosynthesis Operator’s manual and the Quality control Manual. The tests shown here in the table are recommended for tomosynthesis in addition to MAMMOMAT Revelation and MAMMOMAT Inspiration Quality control tests   Testing is required to ensure adequate phantom image quality of the system.  The test should be performed in the 0 degree position only. ACR RMI 156 phantom and a 26 x 35cm TOMO Compression plate are required Create a new patient record in the local database (i.e., Tomo Phantom) Procedure-QC RAW AEC/28 kv Advanced Settings: OpComp ON Auto decompression OFF AEC Segmentation OFF Dose Level "NORMAL"   Mount the compression plate and perform compression and perform a Tomo scan. After reconstruction, scroll through the slices and select the slice where the objects (Fibers, Specs, Masses) are best visible. Evaluate the image by using the magnification tool, zoom or grayscale inversion and adapt the window values, if helpful.  Number of objects that need to be visible: Fibers ≥ 4    Specks ≥ 3    Masses ≥ 3 Record the result on the Test 4 Test Report Form   Test 2 Objective: To check the localization accuracy. Equipment required: 15cm x15cm PMMA plates with a thickness of 20mm ACR Phantom 25cm x 36cm tomo compression plate Procedure: Create new patient Select the procedure QC-raw Tomo Select AEC exposure technique Place a 20mm thick PMMA on the object table Position the ACR phantom according to the figures shown Next perform a ≥ 90N compression to secure the phantom and PMMA in position. Perform a regular Tomo scan using 30kV After the reconstruction, scroll through the slices and select the slice, where the objects (Fibers, Specks, Masses) are best visible.  Measure X and Y using the distance line (Tools > Distance) and record the values in Test 2a) Test Report (reconstructed). Repeat for phantom position No. 2 and No. 3 X and Y measurements and the Test 2a) Test Report The measured X and Y must be within +/-2% of the physical dimension of the ACR phantom.     Click the tabs below to follow the procedure for determining the Z resolution accuracy. Scroll to the slice where the specs of the ACR phantom are best visible. In this slice, zoom into the area with the largest specks and measure the following mean pixel values (see the figure shown for details): S(z0) = the average of the maximum pixel values of each of the 6 specks S(bg0) = mean value of the background (between the specks) Note the two values of S(z0) and S(bg0) in the Test 2b) Test Report.   Here is an example showing the slice with all specks in focus. Slice height is 26mm x 61mm. Figure showing 6 circled ROIs with each of the specks inside.  Max pixel values highlighted in red. S(z0): Average of the maximum pixel values of these 6 specks Figure showing 5 ROIs.  Mean pixel values highlighted in blue S(bg0): Average of the the mean pixel values of these 6 background ROIs. Measurements on slice heights: 24mm, 25mm, 27mm and 28mm Calculate ASF(i) defined as the ratio of (s(zi)-s(bgi)) to (s(z0)-s(bg0)). ASF(a) is then calculated as the average of ASF(-1) and ASF(+1); ASF(b) is then calculated as the average of ASF(-2) and ASF(+2). ASF(a) must be less than 0.9 and ASF(b) must less than 0.6. Evaluate the ASF(a) and ASF(b) for phantom position No. 2 and No. 3 and document the results in the Test 2b) Test report.  In case the ASF function of Z-resolution fails, please inform Siemens Customer Service for corrective action. In a Radiation field test, the image must not show any edges of the collimator or compression plate. Compression plate shown in both +25 and -25 degree projection views. If collimator or compression plate edges show in the test, inform Siemens Customer Service for corrective action. Test 4 Objective: to ensure adequate phantom image quality. Equipment required: ACR phantom (RMI 156) 25cm x36cm tomo compression plate Four tomo scans: 0 degree angulation 0 degree angulation with phantom upside down 90 degree angulation 90 degree angulation with phantom upside down Procedure: Create new patient Select the procedure QC-raw Tomo Select AEC exposure technique Auto decompression set to off Position the ACR phantom on the object table Mount the compression plate and perform compression Perform a Tomo scan. Evaluate the slice where the objects are best visible Repeat steps 3 through 7 with the phantom upside down Repeat steps 3 through 7 with 90° angulation – auto decompression off Repeat steps 3 through 7 with 90° angulation and phantom upside down – auto decompression off 0° angulation 90°angulation Number of objects that need to be visible: Fibers >  4, Specks >  3, Masses > 3 Reconstructed tomo slice with a slice height of 36mm showing 6 fibers, 3 speck groups, and 4 masses.   If the maximum visible objects are below the required limits, please inform Siemens Customer Service for corrective action.   Test 5 objective: To Check for small particles (like dust), slight damages or other artifacts in the X-ray beam path. Equipment required: Collimator mountable 40 mm PMMA phantom 25cm x 36cm tomo compression plate Procedure: Create new patient Select the procedure QC-raw Tomo Select AEC exposure technique Mount the 40 mm PMMA phantom on the collimator Attach the compression plate, and compress until the paddle touches the image receptor cover Perform a Tomo scan. Check the projections/slices for clinically-relevant artifacts such as defective pixels, collections of defective pixels, or defective lines/columns. Use the magnification tool, select the acquired image size and adapt the window values. There should be no clinically relevant artifacts visible in the image. If there are remaining clinically relevant artifacts, please inform Siemens Customer Service for corrective action. Test 1 Objective: to ensure the Tomo unit is compliant with maximum Average Glandular Dose values. Equipment required: 15cm x15cm PMMA plates with thickness of 20mm, 40mm, and 60mm 25cm x 36cm tomo compression plate Procedure: Create new patient Select the procedure QC-raw Tomo Select AEC exposure technique Place a 20mm thick PMMA on the object table Perform compression until OpComp is reached Perform a Tomo scan with specified kV values and thickness Record the mAs and AGD in the Test 1 Test Report   You should now be able to: Define Tomosynthesis and the risks vs. benefits. Identify the system specifications needed to perform tomosynthesis. Differentiate between image acquisition parameters. Utilize post-processing tools to optimize image impression. Differentiate between 2D and 3D image acquisitions. Identify the necessary reconstruction for breast type. List the quality control physicist requirements for tomosynthesis. Review quality control requirements for the technologist.   Welcome to this Interactive Exercise.  In this exercise, you will perform a checklist on the Performing Detector Calibration process. Procedure Checklist Procedure Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLInstall the 40 mm Plexiglass plate on the swivel arm so that the entire image area is covered.  Move the swivel arm to the 0° position.  Remove the compression plate.Step 2HTMLSelect Patient > Detector Calibration from the main menu of the Examination task card. Calibration is automatically registered and the Calibration subtask card is displayed. The next required step, type of calibration, and date of the last calibration is shown.   If a “ ! ”  appears, the calibration is overdue. When the calibration subtask is selected, the correct exposure parameters are automatically set and displayed in the generator control field for each anode/filter combination.Step 3HTMLWhen calibration is started, the Calibration subtask card for the type of calibration selected changes. The projection view to be acquired is shown in the Images subtask card.  At least 7 displayed exposures must be taken. Press the exposure button on the control box until all 26 exposure pulses have been completed. The gantry will remain in 0° position.  Radiation is released and the first calibration image is taken. After the exposure is complete, the finished image is displayed in the image area.Step 4HTMLClick Accept.  if the exposure is suitable for calibration. Windowing may be required to check image quality. The detector is re-calibrated on the basis of the calibration image.Step 5HTMLIf the exposure is not suitable, click Reject. The calibration image is rejected and a new exposure is added. The calibration process ends as soon as you have calibrated the detector using a sufficient number of suitable acquisitions.  At least seven images are recommended. Confirm to start calibration calculation. Welcome to this Interactive Exercise.  In this exercise, you will perform a checklist for the Tomosysthesis Examiniation - Preparation process. Procedure Checklist Procedure Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLIn the Open patient subtask card, select the required tomo procedure and the required projection sequence preset (PAO).Step 2HTMLIn the Aquisition subtask card, select the desired exposure technique in the Exposure selection list.Step 3HTMLIf an implant is present, select the type of implant in the Implant list.Step 4HTMLIn the Reconstruction Parameter Group (RPG) list, select a reconstruction parameter (Standard, Calcification or Phantom).Step 5HTMLPosition the patient.  Use tomo paddles (24cm x 30cm low edge or 25cm x 36cm).  Use face shield.Step 6HTMLLower the compression plate with the control knob or foot switch and compress the breast with a force of at least 30 N to prevent the breast from moving. Welcome to this Interactive Exercise.  In this exercise, you will perform a checklist for the Examination - Reprocessing process. Procedure Checklist Procedure Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLFrom the Tomo Subtask card:   Click the Reconstruct... button OR Right-click on the Reconstruct Tomo Scan icon in the ImagesSubtask Card and select Recontruct Tomo Scan OR Right-click in the image.  Select Recontruct Tomo Scan from the dialog box displayed. Step 2HTMLFrom the Reconstruction of scan dialog box, select a reconstruction parameter from the Reconstruction parameter group name list - Standard, Calcification or Phantom.Step 3HTML Disable the following projection before starting the reprocessing. Welcome to this Interactive Exercise.  In this exercise, you will perform a checklist for the Examination - Acquiring Exposure process. Procedure Checklist Procedure Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLFrom the Tomo Subtask card, click the Slices button. The slice views are displayed.  Select the image you want to delete.Step 2HTMLClick the Delete Reconstruction button on the card Or Right- click on the image. Select Delete Reconstruction in the popup menu that appears.Step 3HTMLFrom the dialog box, click Yes to make the changes. The stored series with the selected reconstruction parameter in the Patient Browser are deleted. Click No if you don't want to make the changes. Welcome to this Interactive Exercise.  In this exercise, you will perform a checklist for the Test 1 Average Glandular Dose process.   Procedure Checklist Procedure Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLCreate new patientStep 2HTMLSelect the procedure QC-raw TomoStep 3HTMLSelect AEC exposure technique.Step 4HTMLPlace a 20mm thick PMMA on the object table.Step 5HTMLPerform compression until OpComp is reached,Step 6HTMLPerform a Tomo scan with specified kV values and thicknessStep 7HTMLRecord the mAs and AGD in the Test 1 Test Report. Welcome to this Interactive Exercise.  In this exercise, you will perform a checklist for the Test 2 Geometric Accuracy process. Procedure Checklist Procedure Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLCreate new patientStep 2HTMLSelect the procedure QC-raw TomoStep 3HTMLSelect AEC exposure techniqueStep 4HTMLPlace a 20mm thick PMMA on the object table.Step 5HTMLPosition the ACR phantom according to the figures shown. Step 6HTMLPerform a ≥ 90N compression to secure the phantom and PMMA in positionStep 7HTMLPerform a regular Tomo scan using 30kVStep 8HTMLAfter the reconstruction, scroll through the slices and select the slice, where the objects (Fibers, Specks, Masses) are best visible. Step 9HTMLMeasure X and Y using the distance line (Tools > Distance) and record the values in Test 2a) Test Report (reconstructed).Step 10HTMLRepeat for phantom position No. 2 and No. 3 Welcome to this Interactive Exercise.  In this exercise, you will perform a checklist for the Test 2 - Geometric accuracy - Z process. Procedure Checklist Procedure Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLScroll to the slice where the specs of the ACR phantom are best visible.Step 2HTMLIn this slice, zoom into the area with the largest specks and measure the following mean pixel values: S(z0) = the average of the maximum pixel values of each of the 6 specks S(bg0) = mean value of the background (between the specks) Note the two values of S(z0) and S(bg0) in the Test 2b) Test Report.Step 3HTMLPerform measurements on slice heights of 24mm, 25mm, 27mm, and 28mm.Step 4HTMLCalculate the ASF(i) defined as the ratio of (s(zi)-s(bgi)) to (s(z0)-s(bg0)). ASF(a) is then calculated as the average of ASF(-1) and ASF(+1); ASF(b) is then calculated as the average of ASF(-2) and ASF(+2). ASF(a) must be less than 0.9 and ASF(b) must less than 0.6.  Step 5HTMLEvaluate the ASF(a) and ASF(b) for phantom position No. 2 and No. 3 and document the results in the Test 2b) Test report. Welcome to this Interactive Exercise.  In this exercise, you will perform a checklist for the Test 4 Phantom Image Quality process. Procedure Checklist Procedure Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLCreate new patientStep 2HTMLSelect the procedure QC-raw TomoStep 3HTMLSelect AEC exposure techniqueStep 4HTMLPosition the ACR phantom on the object tableStep 5HTMLMount the compression plate and perform compressionStep 6HTMLPerform a Tomo scan.Step 7HTMLEvaluate the slice where the objects are best visibleStep 8HTMLRepeat steps 3 through 7 with the phantom upside downStep 9HTMLRepeat steps 3 through 7 with 90° angulationStep 10HTMLRepeat steps 3 through 7 with 90° angulation and phantom upside down Welcome to this Interactive Exercise.  In this exercise, you will perform a checklist for the  Test 5 - Artifact Detection process. Procedure Checklist Procedure Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLCreate new patient.Step 2HTMLSelect the procedure QC-raw Tomo.Step 3HTMLSelect AEC exposure technique.Step 4HTMLMount the 40 mm PMMA phantom on the collimator.Step 5HTMLAttach the compression plate.  Compress until the paddle touches the image receptor cover.Step 6HTMLPerform a Tomo scan.Step 7HTMLCheck the projections/slices for clinically-relevant artifacts such as defective pixels, collections of defective pixels, or defective lines/columns.Step 8HTMLUse the magnification tool, select the acquired image size and adapt the window values.  There should be no clinically relevant artifacts visible in the image.   A Clinical Approach to Tomosynthesis By the end of this module the learner will be able to: List the accessories necessary to perform a tomosynthesis mammography study Identify the steps necessary to perform a tomosynthesis mammography study Identify the steps necessary to perform calibration and phantom quality control tests   Tomosynthesis: a special kind of mammogram that produces a 3-dimensional image of the breast by using low dose x-rays obtained at different angles.    Breast is positioned and compressed in the same way it is for a mammogram X-ray tube moves in a circular arc around the breast.  Approximately 10 seconds for the imaging.  Information from the x-rays is sent to a computer, which produces a focused 3-D image of the breast. Dose is similar to that of a regular mammogram.   Siemens mammography tomosynthesis study: approximately 75 seconds from exposure to the end of reconstruction captures 25 projections with a tube angle of 25º in each direction Click the links below to view a video and a step by step instruction of the process to complete a study. Performing a TOMO Study Video Performing a TOMO Study video   Performing a TOMO Study Checklist Performing a TOMO Study Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLFrom the scheduler, select the patient, and register your patient. Step 2HTML Choose a Tomo procedure in one of the following ways: Option 1: If there is a RIS procedure, the correct procedure will automatically populate in the procedure dropdown on the Open Patient subtask card.   Option 2: Select “2D + Tomo” from the Options menu   Option 3: From the procedure dropdown on the Open Patient subtask card, select a pre-defined Tomo procedure. Step 3HTMLActivate the first icon in the icon gallery.  Step 4HTMLPosition patient, and compress.  Step 5HTMLPerform exposure. This will be a long exposure. Compression will release after the exposure is completed.    Step 6HTMLThe First view will appear with the Bounding Box displayed. The reconstructions will begin immediately and will take 41 seconds to complete.  Step 7HTMLThe next exposure will automatically be activated. Step 8HTMLPerform any additional exposures as needed. NOTE:  If a “2D + Tomo” had been selected, when the exposure is completed, the First view will be a normal 2D image that can be used for diagnostic purposes. After initial reconstruction, an evaluation of the images should be performed.  If the volume from the initial capture needs to be adjusted or if the physician requests a different Reconstruction Parameter Group (RPG), an additional reconstruction must be performed.  Click the links below to view a video and a step by step procedure of the image review process. Review of Images Video Review of Images Video   Review of Images Checklist Review of Images Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLClick on the First view icon in the Tomo subtask card. The First view with the bounding box is displayed.  Step 2HTMLClick the Projection Views Icon in the Tomo subtask card to review individual projections. Step 3HTMLClick the Slices icon in the Tomo subtask card to view the reconstructed slices. Step 4HTML Adjust the Bounding Box, if necessary by clicking on the bounding box, and dragging from the boxes. Step 5HTML   Click on the "Reconstruct…" button,  to reconstruct this image with your new settings There will now be an additional Reconstruction listed in the Reconstr available dropdown in the Tomo subtask card. Step 6HTML There are 3 options to adjust the Reconstruction Parameter Group (RPG) if requested by the Radiologist.  Option 1   Click the  Reconstruct… button   From the RPG name dropdown, select the correct RPG. Click Ok.   Option 2   Right click the image icon.   Select Reconstruct Tomo Scan.  The Reconstruction of Scan window opens.   From the RPG dropdown, select the correct RPG.  Click Ok.   Option 3   Right click the image itself.   Select Reconstruct Tomo Scan.  The Reconstruction of Scan window opens.   From the RPG dropdown, select the correct RPG.  Click Ok.   Step 7HTMLIf more than 2 Reconstructions are in the Reconstr…available dropdown in the Tomo subtask card, this message will appear when you try to close the patient.                 Step 8HTML Delete any unnecessary reconstructions. In the Tomo subtask card, select the reconstruction to be deleted from the Reconstr. Available dropdown box and click Delete Reconstuction.     Step 9HTMLOn the Close Exam sub task card, close the exam. Calibration Test  - must be completed every three months or if the room temperature deviates by more than 7º C  or 12.4º F from the temperature at the last calibration.    Phantom Test  - must be completed on any day that a tomosynthesis study will be performed. The Calibration test is performed quarterly to ensure the system is properly calibrated for tomosynthesis studies. Click the links below to view a video and step by step instructions for the Calibration test process. Calibration Video Calibration Video   Calibration Checklist Calibration Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTMLFrom the Patient drop down menu, select Detector Calibration. Step 2HTMLOn the Calibration subtask card, select Tomosynthesis for the calibration type. Click Start Calibration.  Step 3HTML   7 scans will populate into the image icon gallery. The system automatically populates the manual technique Step 4HTMLAttach the 40mm collimator mountable PMMA phantom. Step 5HTMLRemove the compression paddle. Step 6HTML The first icon will automatically enable. Step 7HTML Press the exposure button on the control box until all 26 exposure pulses have been completed.  The gantry will remain in 0 degree position         Step 8HTML For each exposure, Click ACCEPT if the exposure is suitable.  Click REJECT if the exposure is not suitable.  If an image is rejected, a new exposure icon is automatically added. NOTE:  As you acquire or accept an image, the number acquired or accepted will increase.  Windowing may be required to evaluate image quality   Step 9HTML Repeat steps 7 and 8 until you have produced 7 suitable exposures. Step 10HTML  The calibration process ends, and the following message appears:   Confirm by clicking YES Step 11HTML When calculation is successful, the following message window displays:  Confirm with OK.  Calibration closes automatically. Step 12HTMLRecord calibration complete on the appropriate QC form.Step 13HTML  When calibration is unsuccessful, the following message will appear. “Detector calibration process has successfully performed in Tomosynthesis mode.  The criteria for image quality are out of range.   Image quality may be insufficient.  Please call service.” This means that non-functioning pixels were found during calibration and a system check must be performed by a Siemens service technician. The Phantom Test must be completed on any day that a tomosynthesis study will be performed. Click the links below to view a video and step by step instructions for the Phantom test process. Phantom Video Phantom Video   Phantom Checklist Phantom Checklist Checklist TitleChecklist TypeChecklist ContentStep 1HTML  Register a patient named TOMO PHANTOM. Step 2HTML   From the Procedure dropdown in the Open Patient subtask card, select the procedure “QC RAW TOMO”, Step 3HTML From the exposure dropdown menu, select AEC 28kvp and W/rh filter. Step 4HTML  Click the Adv. Button, to open ADVANCED SETTINGS Step 5HTML  Select the following in the Advanced Settings dialog box: Auto Decomp : OFF  OpComp: ON AEC Segmentation: OFF  Dose Level: Normal Step 6HTML   Position Phantom on detector center with no gap. Step 7HTMLPerform compression to OpComp. Step 8HTMLPerform exposure.   Step 9HTML After reconstruction, scroll through the slices and select the slice where the objects are best visible. To evaluate the image, use the magnification tool, zoom, or grayscale inversion to adapt the window values, if necessary.   If the viewing conditions are considered to be poor when the image is reviewed on the AWS, send the image to the reporting station for further examination.  Ensure that the following number of objects are visible: Fibers: 4 or more, Specks: 3 or more, Masses: 3 or more   Step 10HTMLFlip the phantom over, with the wax insert facing the detector. Step 11HTMLRepeat steps 3 – 7.Step 12HTML  Record the result on the Test 4 Test Report form. Step 13HTML   On the Close Exam sub task card, close the exam. The learner should now be able to: List the accessories necessary to perform a tomosynthesis mammography study Identify the steps necessary to perform a tomosynthesis mammography study Identify the steps necessary to perform calibration and phantom quality control tests   The Tomo subtask card contains all the necessary tools to complete a tomographic study.  Hover your mouse over the image below to see details about each tool.  By the end of this module the learner will be able to: Define Tomosynthesis and the risks vs. benefits. Identify the system specifications needed to perform tomosynthesis.   The learner should now be able to: Define Tomosynthesis and the risks vs. benefits. Identify the system specifications needed to perform tomosynthesis.   By the end of this module the learner will be able to: Differentiate between image acquisition parameters. Utilize post-processing tools to optimize image impression. Differentiate between 2D and 3D image acquisitions. Identify the necessary reconstruction for breast type.   The learner should now be able to: Differentiate between image acquisition parameters. Utilize post-processing tools to optimize image impression. Differentiate between 2D and 3D image acquisitions. Identify the necessary reconstruction for breast type.   By the end of this module the learner will be able to: List the quality control physicist requirements for tomosynthesis. Review quality control requirements for the technologist.   The learner should now be able to: List the quality control physicist requirements for tomosynthesis. Review quality control requirements for the technologist.   The detector should be calibrated every 3 months.   The calibration should also be performed if the room temperature deviates by more than 7 °C from the temperature at the last calibration.   It is recommended that the tomosynthesis calibration be performed after contact calibration. Install the 40 mm Plexiglass plate on the swivel arm so that the entire image area is covered.   Move the swivel arm to the 0° position.   Remove the compression plate.   Select Patient > Detector Calibration from the main menu of the Examination task card. Calibration is automatically registered and the Calibration subtask card is displayed. The next required step (1), type of calibration (2), and date of the last calibration (3) is shown.   If a “ ! ” (4) appears, the calibration is overdue. When the calibration subtask is selected, the correct exposure parameters are automatically set and displayed in the generator control field for each anode/filter combination.     When calibration is started, the Calibration subtask card for the type of calibration selected changes (1). The projection view to be acquired is shown in the Images subtask card (2).  At least 7 displayed exposures must be taken. Press the exposure button on the control box until all 26 exposure pulses have been completed. The gantry will remain in 0° position.  Radiation is released and the first calibration image is taken. After the exposure is complete, the finished image is displayed in the image area. Click Accept (3)  if the exposure is suitable for calibration. Windowing may be required to check image quality. The detector is re-calibrated on the basis of the calibration image. If the exposure is not suitable, click Reject (4). The calibration image is rejected and a new exposure is added. The calibration process ends as soon as you have calibrated the detector using a sufficient number of suitable acquisitions.  At least seven images are recommended. Confirm to start calibration calculation. At the beginning of an examination the patient must be registered either manually or via the RIS/Scheduler.  After entering the required examination data in the patient registration window, click the exam button.  The examination task card is opened.    In the Open patient subtask card, select the required tomo procedure (1) and the required projection sequence preset (PAO) (2).   In the Aquisition subtask card, select the desired exposure technique in the Exposure selection list (1). If an implant is present, select the type of implant in the Implant list (2). In the Reconstruction Parameter Group (RPG) list (3), select a reconstruction parameter (Standard, Calcification or Phantom).   Positioning the patient: Position the patient Use tomo paddles (24cmx30cm low edge or 25cmx36cm) Use face shield Compressing the breast: Lower the compression plate with the control knob or foot switch and compress the breast with a force of at least 30 N to prevent the breast from moving. The exposure to be taken is shown in the images subtask card of the examination task card. Double Click the button shown (1). The acquisition parameters are loaded. Note that the following two settings cannot be changed. The Anode/Filter combination (2) is ALWAYS Tungsten/Rhodium The Grid position (3) is ALWAYS defined to be outside of the field of view. Press and hold the exposure button on the control box as long as the signal is audible. The button will light up yellow during the exposure. Radiation is released and projection images are acquired. The first projection image is the Exposure taken when the swivel arm is at an angle of 0°.  It is acquired for automatic exposure control (AEC).  This image is shown as First View in the image area.  Also shown in the image area is the bounding box, which is the area that will be reconstructed. Following the pre-shot, 25 projection exposures are released for the tomo acquisition. The exposures are acquired successively and the images are captured as a projection view. In the Image subtask card, the individual projection views up to the reconstructed tomo data set are shown here.    OpComp®     OpDose® automatically selects the best anode/filter combination   selects the lowest dose for the individual breast characteristics   adjusted for Tomosynthesis with W/Rh only (to lower dose)   One 2D image < 1 mGy*   One 3D scan ≤ 2 mGy*   * Average with W/Rh  for a 4.5 cm Plexiglas   phantom (PMMA; equivalent   to  5.3 cm breast);   configurable between 1mGy and 2mGy. Tomography software license 26x35cm tomo compression paddle 24x30cm standard low edge compression paddle. Tomography face shield