Optimize Dose Angiography Training

SIEMENS Healthineers Training Optimize Dose Angiography Effective Date: 01/15/2019 | HOOD05162002979037 Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Table of Contents Reduce X-ray dose Recommendations for your daily Introduction routine during interventions Reduce X-ray dose 3 Recommendations for your daily Protect the operator 6 routine during interventions How to A Protect the patient 12 1. Select the adequate protocol 6. Remove grid . Choose a proper organ program "Air Gop Technique" . Replace acquisition by low dose Air Gap Technique Fluoro for small children < 2 . Remove anti-scatter 22 acquisition and/or fluoro as often as possible (= additional absort How to protect the operator Use Fluoro Loop and/or Store Fluoro · Lift up receptor as a reduction measure 1. Collimate if applicable Tips and advice 26 2. Minimize footswitch-on time ................................. · Scattered radiation is approx. proportional to dose area product Patient 7. Dose monitori Example: 50% area means 50% less scattered radiation . The shorter the footswitch-on time, Acquisition Low-dose . CAREwatch: at constant dose acquisition 100% 50% the lower the air kerma Displays the dose vo · Effect: Improved image quality with better contrast Example: Half the time on the patient examination and less scattered radiation pedal results in 50% Less skin dose monitors in the exar and 50% less dose area product for as well as in the con . CAREguard: average patient size Three dose threshold high) can be individ ....................... patient entrance dos 2. Keep an increased distance to the tube audible and visual s Detector · Scattered radiation is mainly generated at beam entrance - 3. Use a low frame rate 8. Use CAREprof stay away from it Operator · Use adequate X-ray shielding products Patient Operator 2 . The lower the frame rate, the lower . Using the Last image · Use alternative angulations to keep the beam entrance further Scattered radiation the air kerma Patient dose as a reference, CARE Example: Half the frame rate results in radiation-free collin from the operator 50% less air kerma and 50% less dose CAREvisio semitransparent filt . Effect on image quality: none area product to precisely target th Tube · CAREvision enables individually adjustable frame rates from 30 fps down to 0.5 fps 3. Follow the rules of the distance square law Detector .................................. 30 15 · Scattered radiation drops with distance squared Operator 1 4. Zoom out as much as practicable Example: Twice the distance means four times less scattered radition 9. Use CAREposi Effect on image quality: none Patient . Increasing the zoom factor increases . CAREposition provid Operator 2 the skin dose area product but decreases skin dose (only for open Zoom level object positioning Input field collimation) Graphic display of th FD 20 x 20 subsequent image a · Effect on image quality. For Large (diagonal] Nominal format/ 25 cm patients at the dose rate limit, 48 Cm table without fluoro Zoom 0 Zoom 1 20 cm 42 cm exposure increasing the zoom factor increases 4. Shield as much as possible .................. image quality. For small patients, Zoom 2 16 cm 32 cm Zoom 3 10 cm 22 cm decreasing the zoom factor increases Zoom 4 10 cm image quality Zoom 5 11 cm Scattered radiation is attenuated by matter ........................................ 5. Use shallow angles as much as possible · Typical shields - Apron (lead) . For every 3 cm patient thickness, entrance dose is doubled - Glass shields (lead) Shallow angles reduce air kerma - Glasses (lead) - Lower/upper body protection Constant patient exit dose Constant patient exit dose - Body (tissue, bone) Effect on image quality: none .............................................................................................................................. 5. Bring the monitor as close as possible Detector · Optimal eye-to-monitor distance is 1 meter or less (for non-zoomed display) · Effect on image quality: improved Operator Patient entrance dose Patient entrance dose A91GER-H-000018-C1-20-7600 .......... Tube .............. A97GER-H-000018-01-30-7600 2 Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Why Optimize Dose Angiography? SIEMENS Healthineers Customers needs Clinicians* want to achieve these knowledge by learning from Siemens Healthineers: achieve low patient and operator* dose while keeping • the best possible diagnostic outcome. make most effective use of existing dose reduction tools • available on the X-ray system. how to combine and make best possible use of dose • reduction features. raise dose awareness in order to reduce the accumulated • staff and patient dose. *: cardiologist, radiologist, technician, nurse, radiographer Introduction 3 Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Biological Effects of Radiation Deterministic • Cataracts, reddenning of the skin, epliation, blood changes, eye injury, temporary or permanent sterility, nausea, diarrhoea, central nervous system damage, death Stochastic • Cancer, genetic effects Damage to DNA Introduction 4 Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Biological Effects of Radiation Deterministic injuries • Result from high radiation doses • When large numbers of cells are damaged and die immediately or shortly after irradiation. (Units of Gray) • There is a threshold dose for visible post procedure injury ranging from erythema to skin necrosis. The injury increases in severity as dose increases. Stochastic injuries • No threshold • Post radiation damage, cell descendants are clinically important. Higher dose, the more likely the process. • There is a linear non-threshold dose identifiable for radiation-induced neoplasm and heritable genetic defects (Units of Sievert). Introduction 5 Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Collimate if applicable • Scattered radiation is approx. proportional to dose area product Example: 50% area means 50% less scattered radiation at constant dose Patient • Effect: Improved image quality with better contrast and less scattered radiation To reduce the amount of absorbed and scattered radiation, the X-ray field at the entrance point to the patient should be kept as small as possible by using the collimators. The radiation dose is directly related to the area of the X-ray field. The field should always be limited to the region of interest. Collimation decreases risk of radiation, minimizes scattered radiation and decreases the fog, resulting in a sharper image and better contrast. Protect the 6 operator Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Keep an increased distance to the tube • Scattered radiation is mainly generated at beam entrance – stay away from it S Detector Patient Operator 2 • Use adequate X-ray shielding products Operator 1 • Use alternative angulations to keep the beam entrance further Scattered radiation from the operator • Effect on image quality: none Tube Stay away from the tube side Scattered radiation is mainly generated at the beam entrance location of the patient. Intensity of the scattered radiation is dependent on the distance from its source. Standing farther from the radiation sources will lower the scattered dose absorption. Scattered radiation can be reduced by positioning the C-arm with the tube on the different side of the table when the medical staff works on. The radiation dose is reduced when the X-ray tube is as far as possible from the patient and the detector as close as possible to the patient. Protect the 7 operator Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Follow the rules of the distance square law • Scattered radiation drops with distance squared Example: Twice the distance means four times less Operator 1 Detector scattered radiation Patient • Effect on image quality: none Operator 2 Tube Stay away from the patient Scattered radiation is roughly proportional to the dose area product (DAP) and decreases with distance squared to the location the scatter is generated. The Inverse Square Law states that doubling the distance from a point source of radiation cuts the exposure rate by a factor of four. Distance is the radiation safety factor over which staff members have the largest degree of personal control. Staff members should stay as far from the table as they can during most of the procedure. When near the table, the major source of scatted radiation is the point where the X-ray beam enters the patient. Protect the 8 operator Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Shield as much as possible • Scattered radiation is attenuated by matter • Typical shields • Apron (lead) • Glass shields (lead) • Glasses (lead) • Lower/upper body protection • Body (tissue, bone) Appropriate shielding is mandatory for the safe use of ionizing radiation for medical imaging. • Lead aprons. These aprons protect an individual only from scattered radiation, not the primary beam. • Eye glasses with side shields and thyroid shields. Lead lined glass and thyroid shield likewise reduce most of the exposure to the eyes and thyroid respectively. • Radiation shields can provide substantial protection from radiation during interventional procedures. Shields must be thoughtfully and actively managed to provide optimum protection. The thickness of lead in the protective apparel determines the protection it provides. Protective apparel must contain a minimum thickness of lead. Protect the 9 operator Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Radiation shields Protect the 10 operator Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Bring the monitor as close as possible • Optimal eye-to-monitor distance is 1 meter or less Detector (for non-zoomed display) • Effect on image quality: improved Operator Patient Tube Proper ergonomic positioning is critical for interventionists. Proper orientation of the monitor offers good visual ergonomics and image quality in order to improve the working environment for the operator and to reduce eyestrain and musculoskeletal fatigue. Protect the 11 operator Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Select the adequate protocol • Choose a proper organ program Firste Ungars Physio InSpace ? • Replace acquisition by low dose acquisition and/or Store Einzelbild 4 B/9 30 BY fluoro as often as possible Fluoro 0,5 B DSA Overview • Use Fluoro Loop and/or Store Fluoro 7,5 Bis EKG 3 B/'s 2 0/8 10 L's 15 B/'s As the fluoroscopy/acquisition input dose decreases, the patient radiation dose decreases, but image noise increases. The optimal input dose mode is that which achieves the best balance between image noise and radiation dose. For especially dose-sensitive patients, it is possible to generate a special low-dose acquisition protocol. An acquisition pedal of the footswitch can be configured as a low-dose alternative acquisition. A dose saving of 67% can be achieved by using an acquisition dose of 80 nGy/f instead of 240 nGy/f for interventional cardiology and an acquisition dose of 0.8 μGy/f instead of 2.4 μGy/f for interventional radiology1 . Last-image-hold function and Fluoro Loop option provide means for reviewing parts of a procedure without producing extra radiation. Their routine use is encouraged. 1. 510(k), K123529, 4 CARE Protect the 12 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Minimize footswitch-on time • The shorter the footswitch-on time, the lower the air kerma Example: Example: Half the time on the pedal results in less Acquisition Low-dose acquisition dose area product for average patient size Footswitch-on time: footswitch-on time controls how long the beam is on the body and thus how long the body is irradiated; less time means less radiation. Irradiation time along with collimation is the two most important radiation protection factors directly under the operator’s control. Limit the amount of time spent while radiation is on will reducing exposure dramatically. Protect the 13 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Minimize footswitch-on time • The lower the frame rate, the lower the air kerma Patient dose Example: Half the frame rate results in less dose area product 100% • CAREvision enables individually adjustable frame rates from 80% CAREvision 30 fps down to 0.5 fps 60% 40% 20% fps 30 15 10 7.5 4 3 2 1. 0.5 The radiation dose is directly related to the frame rate. High frame rates are used to visualize fast motion without stroboscopic effects. However, the higher the frame rate, the more radiation. Therefore it is best to keep the frame rate as low as possible. A commonly used frame rate is 15 frames/s in the cardiac catheterization laboratory. The choice of optimal frame rate depends primarily on the complexity of coronary anatomy and the heart rate. At higher heart rates, a higher frame rate might be necessary for proper visualization of details of the objects. The reduction from 30 fps to 7.5 fps at 70 kV results in a dose saving up to 75%1 . 1. 510(k), K123529, 1 CARE Protect the 14 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Zoom out as much as practicable • Increasing the zoom factor increases the skin dose area product but decreases skin dose (only for open collimation) Zoom Level Input field FD 20 × 20 Zoom dose FD 30 x 40 Zoom dose FD 30 x 30 Zoom dose • Effect on image quality: For large patients at the dose rate (diagonal) factor (diagonal) factor (diagonal) factor limit, increasing the zoom factor increases image quality. For Nominal format/ 25 cm 83% 48 cm 50% 39 cm 57% Zoom 0 Zoom 1 20 cm 110% 42 cm 50% 32 cm 70% small patients, decreasing the zoom factor increases image Zoom 2 16 cm 143% 32 cm 71% 26 cm 84% Zoom 3 10 cm 220% 22 cm 100% 20 cm 110% quality Zoom 4 16 cm 142% 16 cm 140% Zoom 5 11 cm 200% 10 cm 220% The choice of magnification (zoom) has a major effect on the detector entrance dose requirements and on patient dose. Smaller fields of view (FOVs) usually require higher dose rates than larger FOVs. Flat-panel systems typically increase dose inversely proportional to the input field diagonal. Protect the 15 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Use shallow angles as much as possible • For every 3 cm patient thickness, entrance dose is doubled Constant patient exit dose Constant patient exit dose • Shallow angles reduce air kerma 20 cm at 0ª 20 cm water 23 cm water 26 cm water 25.6 cm ot 45ª 28.5 cm at 55º 360%/ 100% 200% 400% 700% 100% Patient entrance dose Patient entrance dose An increase in patient’s thickness of about 3 cm results in twice the patient entrance dose for a constant detector entrance dose. A similar effect occurs when the direction of projection is changed to an oblique position. Because the shape of the body is more oval than circular, the length of the X-ray beam is now longer, resulting in a higher entrance dose. True values may differ significantly since the body is not really a homogeneous ellipsoid but consists of bones, organs, etc. Protect the 16 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Lower SID as much as applicable • Lower source image distance (SID) as much as applicable and Grid in use anti-scatter grid (except for Air-Gap-Technique) • Increase SID results in the equipment's feedback system to increase X-ray output. It is important to keep image receptor Patient as close as possible to the patient Patient dose increases with increasing image-receptor-to-patient distance. Therefore, the X-ray system should be positioned so that the distance from the patient to the image detector is minimized. Raising SID increases patient entrance dose. Protect the 17 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Use CAREposition • CAREposition provides radiation-free object positioning • Graphic display of the outline of the subsequent image allows panning the table without fluoroscopic radiation exposure CAREposition On the last image hold (LIH) screen, • CAREposition allows patient positioning without fluoroscopy while moving the table or C-arm. • CAREposition provides radiation-free patient positioning Protect the 18 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Use CAREprofile • Using the last image hold (LIH) as a reference, CAREprofile allows radiation-free collimation and semitransparent filter position setting to precisely target the region of interest On the last image hold (LIH) screen, • Radiation-free adjustment of collimators • Radiation-free semitransparent filter position setting Protect the 19 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Use CAREmonitor • Real-time visualization of accumulated peak air kerma according to current projection and collimation CAREmonitor • Automatic update of accumulated air kerma calculation upon every system change 2.0 Gy 10 18 • Warning message is displayed if the configured threshold has been reached in the current projection Protect the 20 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Dose monitoring • CAREwatch: Displays the dose area product (DAP), the air kerma rate or the air kerma at the interventional reference mGy A: 0 point on the live display in the examination room and control UGym2 A:0.95 room. • CAREguard: Three dose threshold values (low, medium, and high) can be individually defined. If the accumulated patient entrance dose exceeds the threshold, an audible warning and a warning pop-up is displayed on the tableside touch screen. • CAREreport provides detailed information on the dose applied ----------- in a case in a DICOM structured overview or as XA image. Protect the 21 patient Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Scatter suppression techniques Detector no grid Air gap Detector + anti-scatter grid • Scatter radiation is generated inside the Anti-scatter grid patient and delivers up to 10 times more signal to the detector than primary Air gap radiation. For babies, very thin patients or objects, scattered radiation can be Scatter radiation expected very low anyways. Primary radiation • A simple way to reduce the dose in ...... ..... Max. pediatric examinations is to remove the SID anti-scatter grid for small patient <20kg. To compensate for the remaining scatter, Air Gap Technique should be used! Focus Air Gap 22 Technique Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Scatter suppression techniques in large patients 100% 40% 11 Anti-scatter 75% 20% Air gap grid technique Scatter radiation Primary radiation Anti-scatter grid is 100% 100% 100% beneficial as there is 100% a huge compression of scatter radiation. Air Gap 23 Technique Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Scatter suppression techniques in small patients 100% 40% 11 Anti-scatter 75% 20% Air gap grid technique Scatter radiation Primary radiation Air gap technique is 100% 100% 100% beneficial as there is 100% no loss of primary signal. Air Gap 24 Technique Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Hints and Setup for Air Gap Technique Hints for Air Gap Technique • Using a distance between the patient and the image receptor (air gap) to avoid scattered radiation entering the image receptor. • Using a larger FD input field because the bigger object-to-image distance (OID) will result in a larger display of details. • Using the micro focus to compensate the blur with increased OID. • This technique is recommended for small patients up to 15/20kg or for small organs such as hand or forearm (shunt angiograms). • Air Gap Technique is not recommended with the anti-scatter grid in place Set up (detector 30x40) • Patient in Isocenter • Micro (µ) focal spot • Remove anti-scatter grid • Increase SID Zoom size: 22cm (instead 16 cm for anti-scatter grid) <= main driver here! • Air Gap 25 Technique Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Where to stand when working with C-arm • When using lateral and oblique projections, the intensity of radiation is lower between patient and detector than between tube and patient. For example, in the lateral orientation scatter is about 3 to 10x greater on the X-ray tube side than on the detector side, depending on patient size and section of body irradiated • In many situations, it is required that the physician has to work on the X-ray tube side. For example, biplane cardiac systems are typically configured with the detector on the left side of the patient. In these situations it is even more important to properly use upper body protection shielding along with thyroid protection and lead glasses! Tips and 26 advice Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers System position effects the dose Optimal Table too low Table too low Detector too high 30 cm 1.0 Dose Units 30 cm 60 cm 80 cm 1.4 Dose Units 2.6 Dose Units 50 cm 50 cm Source: Hirshfeld JW Jr, Ferrari VA, Bengel FM, et al. J Am Coll Cardiol. 2018 Jun 19;71(24):2829-2855. 2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in Cardiovascular Imaging-Best Practices for Safety and Effectiveness, Part 2: Radiological Equipment Operation, Dose-Sparing Methodologies, Patient and Medical Personnel Protection: A Report of the American College of Cardiology Task Force on Expert Consensus Decision Pathways. Tips and 27 advice Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 Optimize Dose Angiography SIEMENS Healthineers Managing risks Saving radiation dose from exposure geometry! • Move the X-ray tube away from the patient as far as practicable • Move the image detector as close to the patient as possible • Keep the beam-on time as short as possible • If the image contrast is not affected, remove the grid • Routinely keep hands away from the imaged area and outside the housing of the detector • Use collimation to limit the radiated area, reduce the scatter and maintain image quality • Step back from the patient before engaging fluoroscopy • Use an upper body shield to avoid gap between shielding and patient Tips and 28 advice Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019 SIEMENS Healthineers Please note that the learning material is for training purposes only! For the proper use of the software or hardware, please always use the Operator Manual or Instructions for Use (hereinafter collectively “Operator Manual”) issued by Siemens Healthineers. This material is to be used as training material only and shall by no means substitute the Operator Manual. Any material used in this training will not be updated on a regular basis and does not necessarily reflect the latest version of the software and hardware available at the time of the training. The Operator's Manual shall be used as your main reference, in particular for relevant safety information like warnings and cautions. Note: Some functions shown in this material are optional and might not be part of your system. Certain products, product related claims or functionalities (hereinafter collectively “Functionality”) may not (yet) be commercially available in your country. Due to regulatory requirements, the future availability of said Functionalities in any specific country is not guaranteed. Please contact your local Siemens Healthineers sales representative for the most current information. The reproduction, transmission or distribution of this training or its contents is not permitted without express written authority. Offenders will be liable for damages. All names and data of patients, parameters and configuration dependent designations are fictional and examples only. All rights, including rights created by patent grant or registration of a utility model or design, are reserved. Copyright © Siemens Healthcare GmbH Siemens Healthcare GmbH Henkestr. 127 91052 Erlangen, Germany Phone: +49 9131 84 0 siemens.com/healthineers 29 Effective Date: 01/15/2019 | HOOD05162002979037 © Siemens Healthcare GmbH, 2019