IQ•SPECT for the Technologist - Part 1

IQ•SPECT for the Technologist Part 1 This concludes Part 1 of the course IQ•SPECT for the Technologist.  You should now be able to: State the purpose of IQ•SPECT and describe how it can be used for SPECT and SPECT/CT image quality improvement  Describe the quality control procedures that should be performed prior to acquiring your first patient  List the acquisition and processing workflows used in IQ•SPECT  Demonstrate how to position a patient for a study  Demonstrate how to acquire the scan  By the end of these two courses you should be able to: State the purpose of IQ•SPECT and describe how it can be used for SPECT and SPECT/CT image quality improvement  Describe the quality control procedures that should be performed prior to acquiring your first patient  List the acquisition and processing workflows used in IQ•SPECT  Demonstrate how to position a patient for a study  Demonstrate how to acquire the scan  Demonstrate how to reconstruct a study ​Recognize the differences in IQ•SPECT images when compared to other types of SPECT cardiac studies Then…. Without IQ•SPECT Increasing demand for faster MPI Limitation on the number of detected photons Routine cardiac studies could take up to 20 min. High doses – high radiation exposure Now…. With IQ•SPECT Ultra-fast cardiac imaging with general purpose camera Unique collimator design Cardio-centric image acquisition Advanced reconstruction technology 4x more counts   Click each tab to view additional information about collimation and the SMARTZOOM design. Symbia Intevo Series Minimum Dose & Maximum Speed   IQ•SPECT Acquisition LEHR SPECT Acquisition 4 X counts allows choice of protocol: 4 minute acquisition, full dose 8 minute acquisition, half dose 16 minute acquisition, quarter dose Reconstruction allows choice of protocol: FBP = 16 minute acquisition, full dose cardio•Flash = 8 minute acquisition, full dose cardio•Flash = 16 minute acquisition, half dose Center of FOV magnifies the heart   Edges sample entire body to avoid truncation artifacts   Acquisition is 4 times faster than LEHR   Produces similar clinical results         LEHR Parallel Hole Collimator Imaging Properties      SMARTZOOM Collimator Imaging Properties      SMARTZOOM Magnification of heart with no torso magnification    - 9 secs/view    - 113,000 counts in ROI    - 933 pixels     LEHR   Torso magnification   - 25 secs/view   - 71,000 counts in ROI   - 177 pixels   Images courtesy of Siemens Healthcare The last component of IQ•SPECT is reconstruction.  Click the tabs below to view additional information. Same reconstruction resolution as LEHR collimators in a non-circular orbit   Realizes 4x the sensitivity gain of SMARTZoom collimators   Reconstruction models the geometry of the SMARTZoom collimators and cardio-centric orbit Symbia Detector Orbits are Measured   Collimator Hole Directions are Measured   Enhanced 3D Resolution Recovery   Conjugate Gradient Reconstruction Algorithm is Used (OSCGM)   Low Count Data Handling Perform extrinsic calibration using SMARTZOOM collimators, just like any collimator   Cross pattern is normal   Perform extrinsic sweep verification, just like any other collimator      Specific Acquisition Settings  - IQ•SPECT detector configuration  - Cardio-centric orbit IQ•SPECT Detector Configuration and Cardio-centric orbit can only be selected if:  - SMARTZOOM collimators are installed  - Workflow launched with patient selected  - Acquisition activity to be modified has the token The orbit, detector configuration, zoom and degrees of rotation will default if SMARTZOOM collimators are installed.     Data from SMARTZOOM collimators can only be reconstructed within the AutoRecon processing activity. Flash 3D must be selected as the reconstruction algorithm Flash 3D has been modified for IQ•SPECT reconstruction with SMARTZoom collimator data IQSPECT Processing.wfl: Processes SPECT•CT and SPECT-only data. This workflow can be used for acquisitions acquired with or without scatter and/or attenuation correction. IQSPECT Proc_SPECT only.wfl: Processes SPECT-only data. This workflow is not setup to process data that should have attenuation correction applied.   1.  Install the SMARTZOOM collimators. 2.  Reconfigure the detectors to the IQ•SPECT position. Configurations permitted are 180º, CT, and IQ•SPECT. IQ•SPECT is a new detector configuration. New icon will be available on the PPM. Select the patient in the Patient Browser.   Select the IQ•SPECT workflow template in the Workflow Template Browser.      All IQ•SPECT acquisition workflow templates will have the SPECT Tomo acquisition preceding the CT.   Only differences on Tomo/Gated Tomo activities are the detector configuration and the orbit.   Detector configuration is automatically set to IQ•SPECT and orbit is set to cardio-centric. Settings cannot be changed. Use the pallet up/down, in/out motions to center the patient’s heart in the PPM target box.   If IQ•SPECT positioning cannot be completed without Detector 1 light rail interference, then center the heart in the box as well as possible.   Begin detector focusing process.   If light rail interference is inevitable, stop before the scan completes.   The heart position may not be optimum, so increase the time per view by 5 seconds. Bed height for IQ•SPECT/SPECT•CT scan will be positioned automatically   May not center CT in FOV    Bed height will be chosen to optimize cardio-centric orbit    If CT scan required patient to be centered in CT FOV, operator should adjust height after patient is moved into the CT gantry Perform the CT acquisition. Prepare the SPECT acquisition. The system will move the patient bed out of the CT gantry. Stop the acquisition. Position the patient for an IQ•SPECT acquisition using the previously defined procedures for supine or prone imaging. Re-prepare and perform the SPECT acquisition.  Click each tab to view the parameters for patients who weigh less than 250 pounds and those who weigh more than 250 pounds. High Dose >10 mCi Tc99m High Dose >10 mCi Tc99m   High Dose <10 mCi Tc99m or Tl201    High Dose <10 mCi Tc99m or Tl201   Stop on Time Data is acquired for each view and stops at a time interval Frames will have data from whole heart beats that fall within a defined window during the time interval Study time will be predictable May be noisy if patient has irregular heartbeat   Stop on Beats Data is acquired for each view until a specified number of beats defined in the beat window have been acquired Quality will be guaranteed Study time will be longer if patient has an irregular heart beat Check the Autocentering and Autotracking options. Set width for Beat Window to 40%. Tl 201 analyzer for SPECT•CT:  SC-Tl201-70-NMG Tc99m analyzer for SPECT•CT: SC-Tc99m-NMG   Ensure there is a minimum of 200 mm of FOV in topogram. Place center of topogram at the same level as the center of LV. Ensures that axial CT will be centered on the heart.  ​Images courtesy of Siemens Healthcare Defining Heart Center   Center of Rotation is the Heart:   Detectors are at 104°  ~10 cm between the detectors   Orbit is circular   Rotation arc is 104° The heart is held in the optimal location Cardiac Centric-Orbit   Heart is centered on PPM.  Orbit automatically defined with heart centered in all views. Cardio-centered Orbit ​Images courtesy of Siemens Healthcare MHR Calibration MHR Workflow MHR Results Typical SMARTZOOM Results Typical LEHR Results Tolerances * Expected result values are slightly larger than parallel hole collimators. Use the hand control to raise the detectors to the maximum radial position. Position the patient on the bed in the supine position with their head on the IQ•SPECT Cardiac Armrest and their arms raised over their head.   Center the IQ•SPECT cardiac armrest on the pallet and then use the body wrap to ensure all sheets, blankets, and patient clothing are tucked in. Increase the persistence to 99% on the PPM Persistence tab.  Correct Positioning of Arms Incorrect Positioning of Arms Move the pallet toward the bore until the patient’s heart is centered vertically within the PPM target box. Identify the center of the heart on the Offset Zoom/CT FOV tab and complete the sequence of steps to focus the detectors on the heart. Using the buttons, move the cursor over heart center. Press and hold the Reposition Detectors button until PPM reports that the table is in position. Press the green Proceed button when detector repositioning is complete. Images courtesy of Siemens Healthcare 200 mm of axial CT coverage is required for IQ•SPECT AC. Tap the arrow buttons up and down (in red box) to center the heart. This can also be accomplished by using the CT topogram to plan a 200 mm spiral or sequence CT. Prepare the scan. ​Images courtesy of Siemens Healthcare Use the hand control to raise the detectors to the maximum radial position. Position patient on bed in prone position with arms extended close to the head.   Use the body wrap to ensure all sheets, blankets, and patient clothing are tucked in.   Raise the bed until the patient is centered in the bore.   Manually rotate the detectors clockwise until Detector 1 reaches -121 degrees.  Increase the persistence to 99% on the PPM Persistence tab. Move the pallet toward the bore until the patient’s heart is centered vertically within the PPM target box. Raise or lower the bed until the patient’s heart is centered horizontally within the box. Identify the center of the heart on the Offset Zoom/CT FOV tab. Complete the sequence of steps to focus the detectors on the heart. Prepare for the scan.   ​Images courtesy of Siemens Healthcare ​Images courtesy of Siemens Healthcare