Job Aid Quality Assurance & Quality Control pada CT Scan

SIEMENS Healthineers General Discussion : Performing QA – QC for CT Scan Nur Dwi Prasetyo Workshop Nasional AFMI DPW AFMI Jawa Tengah Semarang, 4 – 5 Mei 2017 Restricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 1 Author / Department HC XX General Question?? SIEMENS Healthineers Procedures and Method? PURPOSED? Personel in charge? Complicated? How Frequent? WHAT ? EQUIPMENTS?? Textmasterformat, Disclaimer Page 2 Author / Department HC XX What is QA Procedures? SIEMENS Healthineers Quality Assurance High Quality Image Least Possible Adequate Exposure Diagnostics - Lowest Cost [WORLD HEALTH ORGANIZATION; Quality Assurance in Diagnostic Radiology, WHO, Geneva .1982] Textmasterformat, Disclaimer Page 3 Author / Department HC XX What is QA Procedures? SIEMENS Healthineers Quality assurance is a comprehensive concept that comprises all of the oversight and management practices developed by the CT imaging team led by the supervising physician to ensure that : 1. Every imaging procedure is necessary and appropriate to the clinical problem at hand 2. The combination of acquisition parameters used for each exam is appropriate to address the clinical question 3. The images generated contain information critical to the solution of clinical problem 4. The recorded information is correctly interpreted and made available in a timely fashion to the patient’s physician 5. The examination results in the lowest possible risk to the patient and is consistent with acquisition parameters [ American College of Radiology ; 2012] Textmasterformat, Disclaimer Page 4 Author / Department HC XX Performance Requirements [IAEA] SIEMENS Healthineers Scan and patient Accuracy SIEMENS SOMATOM Force Image Quality Radiation Dose Textmasterformat, Disclaimer Page 5 Author / Department HC XX What is QC Procedures? SIEMENS Healthineers Bagian dari program QA yang meliputi teknik monitoring dan pemeliharaan alat serta sistem radiologi [Jeffrey Papp; Quality Management in the Imaging Sciences Fourth Edition.2013] Textmasterformat, Disclaimer Page 6 Author / Department HC XX QC Procedures [Acceptance, Corrective, Clinical] SIEMENS Healthineers Clinical Protocols Corrected/ Improved QC QC Image Quality Diagnostics Image Acceptance Test/ Baseline Poor Image Quality Clinical Procedures QC Acceptance Test/ Maintenance Textmasterformat, Disclaimer Page 7 Author / Department HC XX Purposed QC Procedures [Base Line] SIEMENS Healthineers Corrective ... Tolerance Base Line Results Tolerance Measurement Corrective Time/ Period Textmasterformat, Disclaimer Page 8 Author / Department HC XX Personel In Charge QA- QC? SIEMENS Healthineers QA – QC PROGRAMS Registrant/ Licensee Radiologist Medical Physicist Technologist/ Radiographer Textmasterformat, Disclaimer Page 9 Author / Department HC XX Personel In Charge QA- QC? SIEMENS Healthineers REGISTRANT / LICENSEE 1. Ensure that all regulatory and/or licensing requirements are met 2. Ensure that all radiologists, radiographers, medical physicists and other personnel who work at the facility are appropriately qualified and trained and meet all continuing education and experience requirements 3. Ensure that a QA programs is in place that encompasses all aspects of the imaging process, it may be delegated into appropriate staff which has qualification and experiences. [Quality Assurance Programme for Computed Tomography: Diagnostic and Therapy Applications IAEA] Textmasterformat, Disclaimer Page 10 Author / Department HC XX Personel In Charge QA- QC? SIEMENS Healthineers RADIOLOGIST 1. Ensuring that medical physicists and radiographers have adequate training and continuous education courses in CT & Ensuring that all equipment is appropriately maintained 2. Motivating, supervising and managing all aspects related to the QA programme in the area of CT 3. Providing an orientation programme for radiographers based on a carefully established procedures manual 4. Designating a single radiographer to be the primary QC radiographer to perform the prescribed QC tests and oversee those that have been delegated to other individuals [Quality Assurance Programme for Computed Tomography: Diagnostic and Therapy Applications IAEA] Textmasterformat, Disclaimer Page 11 Author / Department HC XX Personel In Charge QA- QC? SIEMENS Healthineers RADIOLOGIST 5. Ensuring availability of the equipment and the necessary materials for the implementation of the QC tests 6. Arranging staffing and scheduling so that adequate time is available to carry out the QC tests and to record and interpret the results 7. Ensuring that a medical physicist is available to oversee the equipment related QC programme and to perform the medical physicist’s tests [Quality Assurance Programme for Computed Tomography: Diagnostic and Therapy Applications IAEA] Textmasterformat, Disclaimer Page 12 Author / Department HC XX Personel In Charge QA- QC? SIEMENS Healthineers RADIOLOGIST 8. Reviewing the radiographer’s test results at least every 3 months, or more frequently if consistency has not yet been achieved, and reviewing the medical physicist’s test results annually, or more frequently as needed 9. Designating an individual to oversee the radiation protection programme for employees, patients and other individuals in the surrounding area 10. Ensuring that records of employee qualifications, mammography technique and procedures, infection control procedures, QC, safety and protection are properly maintained and updated in the CT QC procedures manual 11. Providing feedback continually, both positive and negative, to radiographers on image quality and QC procedures [Quality Assurance Programme for Computed Tomography: Diagnostic and Therapy Applications IAEA] Textmasterformat, Disclaimer Page 13 Author / Department HC XX Personel In Charge QA- QC? SIEMENS Healthineers RADIOGRAPHER 1. Ensuring that the appropriate protocol and technique factors are used for the requested examination 2. Ensuring that the QC tests are performed, interpreted and recorded appropriately. This is best achieved when one radiographer assumes overall responsibility for QC matters and is able to train others to assist in QC activities. 3. Recording imaging problems 4. Undertaking additional continuous education courses. [Quality Assurance Programme for Computed Tomography: Diagnostic and Therapy Applications IAEA] Textmasterformat, Disclaimer Page 14 Author / Department HC XX Personel In Charge QA- QC? SIEMENS Healthineers MEDICAL PHYSICIST 1. Advising the facility on CT image quality and on radiation protection of the patient, staff and members of the public 2. Advising the facility on acquisition, installation and shielding for CT 3. Conducting tests to ensure the safety and proper performance of equipment used in CT. These include acceptance, commissioning and routine QC tests 4. Advising the radiologist and radiographer on optimization 5. Providing oversight and advice to the radiographer who carries out the radiographer’s component of the QC programme. [Quality Assurance Programme for Computed Tomography: Diagnostic and Therapy Applications IAEA] Textmasterformat, Disclaimer Page 15 Author / Department HC XX SIEMENS Healthineers Equipments Quality Control Ct Scan Textmasterformat, Disclaimer Page 16 Author / Department HC XX QC Equipments SIEMENS Healthineers Alat Ukur Radiasi dan Phantom Dosimetry Phantom Image Quality / Performance Phantom Analysis Software Phantom AAPM CT Performance Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 17 Author / Department HC XX Manufactures Phantom SIEMENS Healthineers FDA Recommendations • Contrast Scale • Noise • Tomographic Thickness • Spatial Resolution (High – Low Contrast) • CT Number (reverence material) Unrestricted © Siemens Healthcare GmbH, 2016 Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 18 Author / Department HC XX “Siemens” Standard QC Phantom SIEMENS Healthineers QC Protocols : • CT Slice position • Slice thickness • CT number homogeneity • Noise • Water CT number • MTF • Table positioning Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 19 Author / Department HC XX “General Electric” Standard QC Phantom SIEMENS Healthineers QC Protocols : • Slice position • Slice thickness • Spatial resolution • Low contrast • Noise • Water CT number Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 20 Author / Department HC XX “Philips” Standard QC Phantom SIEMENS Healthineers QC Protocols : • Slice Thickness • Noise & Uniformity • “Impulse Response” (MTF) • Contrast Scale • Low Contrast Detectability • Spatial Measurement Accuracy Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 21 Author / Department HC XX “Toshiba” Standard QC Phantom SIEMENS Healthineers QC Protocols : • Slice Thickness • Noise & Uniformity • “Impulse Response” (MTF) • Contrast Scale • Low Contrast Detectability • Spatial Measurement Accuracy Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 22 Author / Department HC XX SIEMENS Healthineers Procedures and Methods Quality Control CT Scan ACR Quality Control Manual ; 2012 Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 23 Author / Department HC XX QA & QC Procedures for Medical Physicist SIEMENS Healthineers Daily/ Weekly Monthly/ Anually • Visual Inspection & Clinical Protocols Review • Scout Prescription and Alignment Light Accuracy • CT Number Accuracy • Image Thickness – Axial Mode & Sequence Artifact Evaluation QC • Mode • CT Number Uniformity • Table Travel Accuracy • Radiation Beam Width • Image Noise • Dosimetery • Visual Inspection • Hard Copy • Hard Copy • Low-Contrast Performance Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 24 Author / Department HC XX Visual Inspection SIEMENS Healthineers and Review Clinical Protocol Objectives : • Ensure that the CT scanner and adjacent areas are safe. • Ensure that a selection of clinical protocols appropriately utilizes the scanner features • Ensure that these protocols obtain the diagnostic image quality required Frequency : • Acceptance test, Annually or after relevant services Equipments : • Visual programs and review check list • QC Charts and Log • Written Safety procedures Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 25 Author / Department HC XX Visual Inspection SIEMENS Healthineers and Review Clinical Protocol (Objectives) Emergency Equipments (Emergency Button, Fire Extinguisher) Visual Inspection ------- Radiation Protection (Apron, Barrier) Patient Identification Doctor’s Room (Name, ID, Institution, Operator) (Viewing Case, Workstation) Operator Console (Viewing Window, Ergonomic) Check List Example Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 26 Author / Department HC XX Visual Inspection SIEMENS Healthineers and Review Clinical Protocol (Objectives) Review of Clinical Protocols (Adult/ Pediatric, Head/ Abdomen, HR Thorax) Clinical Protocols Acquisition and Reconstruction Parameters (kV, mA, Collimation, Pitch, Reconstruction Slice ) Dose Reduction Methods (Iterative Reconstruction, Dose Modulation) Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 27 Author / Department HC XX Recommendation Regarding Clinical Protocols [AAPM] SIEMENS Healthineers Detector Configuration and Collimation : • The largest value of detector configuration or beam collimation available for the scan should be used whenever practical, as this improves dose efficiency. Acquisition and Reconstruction Factors : • Lower kV settings should be considered for pediatric scans as well as those scans that use intravenous or oral contrast. • High-Resolution Chest (HRC) protocol should incorporate a sharp reconstruction kernel or filter. Clinical Dose : • Doses should be as low as necessary to accomplish the diagnostic task. • Develop radiation dose thresholds during any new CT protocol design. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 28 Author / Department HC XX Scout and Alignment Light Accuracy SIEMENS Healthineers Objectives : • To verify that the incorporated alignment lights correctly indicate the scan position and that the scout image prescription correctly identifies the scan position Frequency : • Acceptance test, Annually or after relevant services Equipments : • Phantom that incorporates externally visible radiopaque fiducial markers or an image-center indication Criteria (IAEA) : • Acceptable ± 5mm, Achievable ± 1 mm (Beam Alignment) • Acceptable ± 2mm, Achievable ± 1 mm (Scout Accuracy) Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 29 Author / Department HC XX Scout and Alignment Light Accuracy SIEMENS Healthineers Test Procedure : (Beam Alignment Accuracy) • Using the alignment lights, carefully position the phantom to the radiopaque markers/ Image center Indication in all 3 orthogonal planes. SIEMENS • Zero the table location indication. • Scan the phantom in axial mode using a reconstructed scan width less than 2 mm or as thin as the scanner can produce Che in axial mode at the zero position. • Use a technique appropriate to the phantom to allow accurate visualization of the fiducial markers; for most phantoms, the adult abdomen technique works well. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 30 Author / Department HC XX Scout and Alignment Light Accuracy SIEMENS Healthineers Analysis : (Beam Alignment Accuracy) • View the image collected • Verify that the visible radiopaque markers are visible in the reconstructed image. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 31 Author / Department HC XX Scout and Alignment Light Accuracy SIEMENS Healthineers 4 4 Distance: 15 Criteria (IAEA) : 3 Acceptable ± 5mm, Achievable ± 1 mm (Beam • 3 Distance: 15.82 cm Alignment) 1 Distance: 35.77 cm1 2 Distance: 35.65 cm Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 32 Author / Department HC XX Scout and Alignment Light Accuracy SIEMENS Healthineers Test Procedure : (Scout Accuracy) • Scan the entire phantom in scout mode. • Magnify the image, if possible, and position a single slice at SIEMENS the location of the radiopaque fiducial markers. • Perform an axial scan using a reconstructed scan width less Che than 2 mm or as thin as the scanner can produce in axial mode. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 33 Author / Department HC XX Scout and Alignment Light Accuracy SIEMENS Healthineers Analysis : (Scout Accuracy) • View the image collected • Verify that the visible radiopaque markers are visible in the reconstructed image. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 34 Author / Department HC XX Scout and Alignment Light Accuracy SIEMENS Healthineers Boulder Community Hosp PHYSICIST BROADWAY CT 1 BCT1 Boulder Community Hosp PHYSICIST BROADWAY CT 1 BCT1 ( GE MEDICAL SYSTEMS Light Speed Plus 6.1 ABDOMEN/PELVIS GE MEDICAL SYSTEMS Light Speed Plus 6.1 ABDOMEN/PELVIS Image size: 512 x 512 StudyID: 3259 Image size: 888 x 292 StudyID: 3259 WL: 100 WW: 400 SeriesID: 20 WL: 100 WW: 400 SeriesID: 120 kVp X: 326 px Y: 236 px Value: -74.00 120 kVp 400 mA X: 0.00 mm Y: 70.24 mm Z: 11.00 mm 40 mA 800 msec 105 msec 300 300 100 100 2 mm Scan Area 100 -100 Criteria (IAEA) : Acceptable ± 2mm, Achievable ± 1 mm (Scout • SFOV: 500 DFOV: 210 SFOV: 500 DFOV: Accuracy) STANDARD STANDARD Im: 1/1 ORIGINAL / PRIMARY / AXIAL AXIAL MODE 1.25 mm, position Q Im: 1/2 ORIGINAL / PRIMARY / LOCALIZER SCOUT MODE p 8/19/09 7:00:59 AM 160.182 mm, position 140 8/19/09 6:32:16 AM Ganrty_Tilt: O Made In Osirix Ganrty_Tilt: 0 Made In Osinix Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 35 Author / Department HC XX Image Thickness SIEMENS Healthineers Objectives : • To ensure that the reconstructed imaged slice width is similar to that selected on the CT scanner console Frequency : • Acceptance test, Annually or after relevant services Equipments : • A phantom with internal targets that allow the determination of reconstructed image thickness Criteria (IAEA) : Nominal Slice (mm) Acceptable ≤ 1 mm < nominal + 0.5 mm >1 mm and ≤ 2 mm ± 50% >2 mm ± 1 mm Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 36 Author / Department HC XX Image Thickness SIEMENS Healthineers Test Procedures : (Sequence Mode) • Align the axial z sensitivity test device so that its axis coincides with the axis of rotation of the CT scanner with the image centred in the FOV. SIEMENS • Perform an SPR to confirm acceptable alignment and to define the tomographic plane. Che • Select a scan protocol. • Scan the test object as required. • Repeat for all other selected scan protocols. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 37 Author / Department HC XX Image Thickness SIEMENS Healthineers Test Procedures : (Helical Mode) • Place the helical z sensitivity test object on the CT couch or secure it on a stand so that it is centred in the FOV and aligned such that the metal foil insert is parallel to the SIEMENS tomographic plane. • Perform an SPR and define the scanned volume for helical scanning to ensure the metal foil is fully imaged. Che • Select a scan protocol. • Scan the test object. • Reconstruct images at intervals of approximately one tenth of the nominal imaged slice width. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 38 Author / Department HC XX Image Thickness SIEMENS Healthineers ( - Data Analysis : CT CT CT ) Max b half = + CT 2 b • Place an ROI over the central portion of each reconstructed image corresponding to the position of the metal disc insert and measure the average CT number in it. 30 • Plot the measured values of the CT number versus image position (distance in the z axis direction) in chart. 25 • Determine CTmax and CTb. 20 • Determine the FWHM by calculating the distance between the two points corresponding to the CThalf values. 15 • Simple linear interpolation may be used to obtain this 10 distance more accurately. This distance represents the imaged slice width . 5 FWHM 0 Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 39 Author / Department HC XX Image Thickness SIEMENS Healthineers MA 3 3 1 Min/Max: 82 /143 1 Mean/SD: 129.3 /12.3 2 Min/Max: 97 /190 2 Mean/SD: 152.8 /20.5 3 Min/Max: 117 /275 3 Mean/SD: 213.9 /36.5 4 Min/Max: 172 /294 4 Mean/SD: 270.2 /24.5 5 Min/Max: 167 /294 5 Mean/SD: 271.6 /24.4 6 Min/Max: 144 /285 6 Mean/SD: 244.1 /31.5 7 Min/Max: 98 /184 7 Mean/SD: 150.7 /19.9 8 Min/Max: 92 /147 8 Mean/SD: 129.6 /11.1 10cm Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 40 Author / Department HC XX Image Thickness SIEMENS Healthineers ( ) - CT CT CT Max b half CT = + 2 b 4 3 Min/Max: 82 /143 Mean/SD: 129.3 /12 2 WOS NN 2 Min/Max: 97 /190 2 Mean/SD: 152.8 /20.5 3 Min/Max: 117 /275 3 Mean/SD: 213.9 /36.5 4 Min/Max: 172 /294 4 Mean/Cn. 170 ) /24.5 5 Min/Max: 167 /294 5 Mean/SD: 271.6 /24.4 6 Min/Max: 144 /285 6 Mean/SD: 244.1 /31.5 ( 7 Min/Max: 98 /184 CT 271.6 129.3 ) 7 Mean/SD: 150.7 /19.9 - 8 Min/Max: 92 /147 8 Mean/SD: 129.6 /11.1 half 129.3 = + 2 CT half 200.3 = 10cm Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 41 Author / Department HC XX Image Thickness SIEMENS Healthineers ( 271.6 129.3 ) - CT half + 129.3 = 2 CT half 200.3 = 280.00 Slice FWHM a = ´ tan 270.00 260.00 250.00 Slice FWHM = ´ tan 45 240.00 230.00 220.00 210.00 Slice FWHM 1 200.00 FWHM = ´ Series1 190.00 180.00 170.00 160.00 150.00 140.00 130.00 120.00 V 1 2 3 4 5 6 7 8 Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 42 Author / Department HC XX Table Travel Accuracy SIEMENS Healthineers Objectives : • To verify that the patient table translates as indicated Frequency : • Acceptance test, Annually or after relevant services Equipments : • A phantom with 2 sets of external fiducial markers of known separation Criteria (IAEA) : • The table translation accuracy and return to a fixed position should be accurate to within 2 mm Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 43 Author / Department HC XX Table Travel Accuracy SIEMENS Healthineers Test Procedures : • If possible, add weight to the tabletop to simulate the weight of an average patient. • Using the alignment light, carefully position the phantom such that the first set of fiducial markers is in the axial plane. • Zero the table position indication. • Move the table to the second set of external fiducial markers. • Record the table position. • Translate the table to full extension and return to the first set of fiducial markers. • Record the new table position. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 44 Author / Department HC XX Table Travel Accuracy SIEMENS Healthineers Data Analysis : Boulder Community Hosp • Compare the distance between the fiducial markers as GE MEDICAL SYSTEMS LICHT Speed Plus 1 ABDOMEN/PE Image size: 888 x 293 StudyID: 3259 WL: 50 WW. 500 determined by the table travel to the known distance. X: 393 px Y: 292 px Value: 303.00 120 kVp X-30.48 mm Y: 0.00 mm Z: -19.45 mm 10 mA 494 msec • Compare the first fiducial marker table position to the new position recorded after the table extension and return. 300 50 Criteria (IAEA) : 200 • The table translation accuracy and return to a fixed position should be accurate to within 2 mm SFOV: 500 DFOV: Imc 2/2 STANDARD 160.182 mm, position 140 ORIGINAL / PRIMARY / LOCALIZER SCOUT MODE 8/19/09 6:32:26 AM Made In Osinix Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 45 Author / Department HC XX Radiation Beam Width SIEMENS Healthineers Objectives : • To measure the radiation beam width and to assess its relationship to the nominal collimated beam width • To determine the extent of over-beaming Frequency : • Acceptance test, Commisioning, Annualy or after relevant services Equipments : • External radiation detector (CR Plate, Gafchromic Film, TLD array) • Atenuator Plate Criteria (IAEA) : • Within 3mm or 30% of Applied Colimator Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 46 Author / Department HC XX Radiation Beam Width SIEMENS Healthineers Test Procedures : • Place film on a flat foam block to minimize scatter on the film. • Raise the couch so that the film surface is on the isocentre of the scanner. • Mark the isocentre of the film. • Scan the film in axial mode for one collimation setting using a set kV and mAs as required to give the film a density that is clearly below the film maximum density. • Repeat for all other selected scan protocols. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 47 Author / Department HC XX Radiation Beam Width SIEMENS Healthineers Data Analysis : • Plot the profile of the density of the exposed film using a film scanning device • Defines the FWHM value for the film, apply the density value for the FWHM to each of the beams plotted to determine the X ray beam width. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 48 Author / Department HC XX Radiation Beam Width SIEMENS Healthineers Criteria (IAEA) : Density • Within 3mm or 30% of Applied Colimator 30 25 20 15 Slice Width 10 5 FWHM 0 Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 49 Author / Department HC XX Low Contrast Performance SIEMENS Healthineers Objectives : • To verify that the low-contrast performance of clinical protocols is adequate for diagnosis Frequency : • Acceptance test, Annualy or after relevant services Equipments : • A phantom that incorporates low-contrast targets of known contrast Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 50 Author / Department HC XX Low Contrast Performance SIEMENS Healthineers Test Procedures : • Align the phantom. • Perform clinical scans covering the low-contrast section of the phantom (No Dose Modulation). • At a minimum, the scans performed should include the following: • Adult head (average) • Pediatric head (1 year old) • Adult abdomen (70 kg) • Pediatric abdomen (5 years old; 40-50 lb, approx. 20 kg) Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 51 Author / Department HC XX Low Contrast Performance SIEMENS Healthineers Data Analysis : (Visual Analysis) • View each series and determine the image that provides the best low-contrast performance. • Adjust the window width/level to optimize visibility of the low-contrast targets. • Record the size and/or contrast of the barely visualized target. Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 52 Author / Department HC XX Low Contrast Performance SIEMENS Healthineers Data Analysis : (Numeric Analysis) • View each series and determine the image that provides the best low-contrast performance . • Place ROI to measure HU number of the target material and structure adjacent the target • Calculate CNR from largest representative target and adjacent background Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 53 Author / Department HC XX Low Contrast Performance SIEMENS Healthineers 25 mm Area 1.048 cm2 6 mm 2 mm Mean: 95. 655 SDev. 5.613 Sum: 62941 Min: 01.000 Max 113.000 150 Area: 1.048 cm2 Mean: 89.599 SDev: 5,600 Sum: 59225 Min: 74.000 Max 106.000 3 mm 1.00 5 mm 4 mm Criteria : Scan protocol CNR Adult Head 1.0 Pediatric Head 1.0 ( T BG ) - Adult Abdomen 1.0 CNR mean mean = Pediatric Abdomen 0.5 BG stdev Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 54 Author / Department HC XX Spatial Resolution SIEMENS Healthineers Objectives : • To ensure that the spatial resolution of a reconstructed image complies with manufacture standards. Frequency : • Acceptance test, Annualy or after relevant services Equipments : • A phantom that incorporates with spatial resolution either for visual analysis or MTF analysis Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 55 Author / Department HC XX Spatial Resolution SIEMENS Healthineers Test Procedures : • Align the phantom. • Perform clinical scans covering the low-contrast section of the phantom (No Dose Modulation). • At a minimum, the scans performed should include the following: • Adult abdomen (average) • High Resolution Chest Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 56 Author / Department HC XX Spatial Resolution SIEMENS Healthineers Data Analysis : (Visual Analysis) • View each series and determine the image that provides the best high-contrast target. • Adjust the window width/level to optimize visibility of the low-contrast targets. • Determine and record the highest frequency visible in the image. Data Analysis : (Software Analysis) • Use proper software (some may provide by CT Manufacture) to create MTF for determine spatial resolution Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 57 Author / Department HC XX Spatial Resolution SIEMENS Healthineers Community Hoop 12 GE MEDICAL SYSTEMIS Leht sarad Plus. 6.1 ARDOHEN/PELVIS mode de : 512x512 StudyIC: 0259 WL: 1100 WW. 100 120 BYp 4 400 MA 1121 12 10 1150 15 1100 7 6 Criteria (IAEA) : • Within manufacture criteria SFOV: 500 DFOV: 210 STANDARD Im: 24/25 5 ORIGINAL / PATHWAY / JOOAL HELICAL MODE mm, position" 8/19/09 5:40:32 AM Garrty Tin: 0 Scan protocol Limiting Resolution Adult Abdomen 6 lp/cm High-Resolution Chest 8 lp/cm Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 58 Author / Department HC XX CT Number Accuracy, Artifacts, Noise and Uniformity SIEMENS Healthineers Objectives : • To verify that the CT numbers reported by the CT scanner are acceptably accurate and vary as expected. Frequency : • Acceptance test, Annualy or after relevant services Equipments : • A phantom that incorporates targets that provide different known CT number values. • Phantom provide by manufacture for co-responding test Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 59 Author / Department HC XX CT Number Accuracy, Artifacts, Noise and Uniformity SIEMENS Healthineers Test Procedures : • Align the phantom. • Perform clinical scans covering the low-contrast section of the phantom (No Dose Modulation). • If possible, the scans performed should include the following: • Adult Head • Pediatric Head • Adult abdomen (average) • Pediatric Abdomen Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 60 Author / Department HC XX CT Number Accuracy, Artifacts, Noise and Uniformity SIEMENS Healthineers Data Analysis : (CT Number Accuracy) • Select the image most central to the module containing the CT number accuracy targets. • Adjust the window width/level to optimize visibility of the targets. • Place a circular ROI, approximately 80% of the size of the target, in each target. • Record the measured CT number mean for each target Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 61 Author / Department HC XX CT Number Accuracy, Artifacts, Noise and Uniformity SIEMENS Healthineers CT ACR 464 Phantom modules Definition AS+ A CTLinearity80k' Area:0.3 sq.cm 2010 J C: OPTIRAY 32 Meal:-994.5 HU SU.Deu.: 6.3 HU Se: 8/22 Polyethylene -95 HU Im: 2/3 Bone 955 HU Acq Tm: 10:35:45.328000 Ax S0.0 + 512 x 512 Water Area: 20sq.cm Area: 20sq.cm H37s Meal:-122.4 HU O HU Meat: 1170.1 HU St.Deu.: 7.3 HU SU.Deu.: 11.3 HU Acrylic 120 HU Air -1000 HU Area: 20sq.cm Mear:-0.3 HU SU.Deu.: 90 HU -... + Criteria [IAEA] : 80.0 kV Area:20sq.cm Area:20sq.cm Meal: 110.5 HU Meal: -995.6 HU SU.Deu.: 8.5 HU • Acceptable ± 5 from baseline value, achievable ± 4 300.0 mA SU.Deu.: 5.3 HU 4.8 mm/0.0:1 (water) Tilt: 0.0 1.0 s Acceptable ± 10 from baseline value (material) _in:DCM / Lin:DCM / Id:ID • W:350 L:90 P DFOV: 22.0 x 22.0cm Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 62 Author / Department HC XX CT Number Accuracy, Artifacts, Noise and Uniformity SIEMENS Healthineers Data Analysis : (Noise and Uniformity) • Select image of water phantom (homogen, no air inside). • Adjust the window width/level to optimize visibility of the targets. • Place a circular ROI, at least in 5 position inside the phantom which represent central and peripheral area of the phantom. • Record the measured CT number mean for each target ROI Criteria : Test Type Acceptable Achievable Image noise ±25% of the baseline ±10% of the baseline Uniformity ±10 ±4 Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 63 Author / Department HC XX CT Number Accuracy, Artifacts, Noise and Uniformity SIEMENS Healthineers Data Analysis : (Artifacts) • Select image of water phantom (homogen, no air inside). • Adjust the window width/level to optimize visibility of the targets. • Visual interpretation of image to evaluate a possible artifacts shown Criteria : • No visual artefacts shown in the image Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 64 Author / Department HC XX CT Number Accuracy, Artifacts, Noise and Uniformity SIEMENS Healthineers 20-Apr-ZU17 15:54:14.44 H-SP-CR 2 IMA 1 SPI 2 SP -99.6 3 Min/Max: -6/11 3 Mean/SD: 2.4 /2.8 5 Min/Max: -9/13 5 Mean/SD: 2.0 /3.9 R Tools 4 Min/Max: -7 8 2 Min/Max: -5 /9 2 Mean/SD: 1.3 /2.6 4 Mean/SD: 15 /2.9 1 Min/Max: -4 /11 10cm: 1 Mean/SD: 2.9 /2.7 Patien Criteria [IAEA] : kV 130 eff.mAs 215 ref.mAs 220 No Artifacts shown in the image TI 1.5 • Test Type Acceptable Achievable Image noise ±25% of the baseline ±10% of the baseline Uniformity ±10 ±4 Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 65 Author / Department HC XX Dosimetry SIEMENS Healthineers Objectives : • To measure doses for verification of scanner performance and to allow for calculation of dosimetric quantities relevant to patient exam estimates. Frequency : • Acceptance test, Annualy or after relevant services Equipments : • Calibrated electrometer and CTDI pencil ionization chamber (10- or 15-cm long) • 16-cm (head) CTDI dosimetry phantom • 32-cm (adult body) CTDI dosimetry phantom Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 66 Author / Department HC XX Dosimetry SIEMENS Healthineers X-rayy focus Detector Nominal slice thickness 5 Dose Dose prolile D(z) Nominal slice thicknes. on for Medical Education and Research. All rights reserved. DOLE Textmasterformat, Disclaimer Page 67 Author / Department HC XX CTDIw dan CTDIvol SIEMENS Healthineers y CTDIw 2 CTDI Peripheral 1 + CTDI central = × × z 3 100 3 100 x O Multi Slice/ VolumetricScan Detector CTDI CTDI w vol = feed perscan è ç æ ö total collimation ø ÷ CTDI CTDI w vol = pitch DLP= CTDI . L [mGy cm] L = Scan lenght Textmasterformat, Disclaimer Page 68 Author / Department HC XX Dosimetry SIEMENS Healthineers Fu CT Dose Profile Analyzer O X File Misc Measure Analyze Report Help System info / Instructions Institution Hospital *Phantom Head Scan length (mm) Viewing saved Department CT *Pitch (-) Scan time (s) measurement Room CT room *Collimation, NT (mm) 10 Tube voltage (kVp) 120 *CT-Unit Siemens Somatom Plus 4 *Tube rotation time (s) Tube current (mA) 200 Note Axiel scan cklockan 12 CT Dose Profiler DP2-0904005 25 1 Det/module: CT-SD16 DC1-0601009 , BC1-02100140 Tester Cavarl at 15.07 2007_10_12 John Smith Measurement type Head|L Max Rec Time (s) 5,12 Dose measurement 40 35- Settings 30- 25 - 20 - 15- 10 Doserate (mGy/s) 5- 0 05 1 1,5 2,5 3 13,5 5 5,5 Time (s) Dose (mGy) 17,03 Time (s) Dose rate (C2-C1) 0,323 el C2/C1 NaN Average (mGy/s max deviation % Jose rate 4,52 range (C1 to C2) 3,77 (range c1 to c2) 941,2 0,00 Time (s) (mGy/s) c1 c2-c1 Plot 2 URTI Dose (mGy) 17,11 Exposure time (s) 5,042 Charge (nc) 74,205 Dose rate (mGy/s) 0,000 CT Dose Profile Analyzer program No Path and file name: C:\ProgramData\RTI Electronics\CT Dose Profile Analyser\ CT-example\Siemens Dose\Siemens|12:29 2009-09-30 kl12_head_dose.xml Criteria : • Dose Calculation in Air : Output at every kVp ±5% from baseline • CTDIvol for clinical protocols : Less than Dose Reference Level • Verify scanner CTDIvol : ±10% Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 69 Author / Department HC XX Conclusion SIEMENS Healthineers QA – QC PROGRAMS Registrant/ Licensee Radiologist Medical Physicist Technologist/ Radiographer Textmasterformat, Disclaimer Page 70 Author / Department HC XX Conclusion SIEMENS Healthineers Daily/ Weekly Monthly/ Anually • Visual Inspection & Clinical Protocols Review • Scout Prescription and Alignment Light Accuracy • CT Number Accuracy • Image Thickness – Axial Mode & Sequence Artifact Evaluation QC • Mode • CT Number Uniformity • Table Travel Accuracy • Radiation Beam Width • Image Noise • Dosimetery • Visual Inspection • Hard Copy • Hard Copy • Low-Contrast Performance Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 71 Author / Department HC XX Rerefences SIEMENS Healthineers ACR® RADIOLOGY QUALITY 18 OUR IMAGE 2012 Computed Tomography Quality IAEA HUMAN HEALTH SERIES Management No. 19 IN THE IMAGING SCIENCES QUALITY CONTROL MANUAL Quality Assurance Programme for Computed Radiologist's Section Tomography: Diagnostic and Therapy Applications JEFFREY PAPP IAEA International Atomic Energy Agency Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 72 Author / Department HC XX SIEMENS Healthineers Thanks all For Your Kind Attention Semarang, 4 – 5 May 2017 Unrestricted © Siemens Healthcare GmbH, 2016 Textmasterformat, Disclaimer Page 73 Author / Department HC XX