Flex 4D Spiral Online Training

Welcome to the Flex 4D Spiral Online Training. This training introduces you to the Flex 4D Spiral feature and provides an overview of available scan modes and dose reduction technologies. In addition, you will learn about the correlation between different scan parameters, for example pitch, scan time, scan length, etc. and how to adjust scan parameters and recon patterns.  Congratulations. You have completed the Flex 4D Spiral Online Training course. Listed below are the key points that have been presented. Take time to review the material before you proceed to the final quiz. Select the link below to view/print your review material before proceeding to the final quiz.  Download a copy of the Course Review.  Introduction to Flex 4D Spiral Flex 4D Spiral is a feature available for CT Imaging that allows for the acquisition of dynamic data beyond the physical size of the detector width. This is achieved by the table that continuously moves forward and backward during the spiral scan. Use cases: Neuro perfusion (stroke) Body perfusion (for example liver perfusion) Dynamic angio (for example cerebral vasculature) Know the available scan modes Depending on your SOMATOM scanner, the following Flex 4D Spiral scan modes may be available:     Scan modes Scan protocols (factory) Flex 4D Spiral (Neuro) Dynamic Spiral Adult Head Brain Perfusion Brain Perfusion prolonged* Dynamic Spiral Adult Head Angio Dynamic CTA Brain  Flex 4D Spiral (Body) Dynamic Spiral Adult Body Liver Perfusion Dynamic Spiral Adult Body Angio Thorax Dynamic CTA Extremity Dynamic CTA   *Neuro Perfusion prolonged is a CT Neuro Perfusion protocol with an extended image acquisition time (max. 120s) for use in certain third party postprocessing solutions. For further details, please contact your local application specialist. Adjust scan parameters and cycle patterns For a Flex 4D Spiral workflow, the following scan parameters can be adjusted: Scan time The scan time is the summation of the cycle time and can be adapted. Adjusting the scan time only and leaving all other parameters the same, will lead to a changed number of cycles. Scan length The scan length is defined by the planned length of the topogram. For a Flex 4D Spiral examination, the maximum scan length is not determined by the physical detector width, but rather by the pitch and the required temporal resolution, for example cycle time. Pitch (depending on selected scan mode) The pitch is a dimensionless acquisition parameter in spiral computed tomography and describes the relation of patient table feed and beam collimation. Exposure pattern In the Exposure Pattern, it is defined which cycles of the entire scan are to be acquired (exposed) during the examination. In the Exposure Pattern list, you can see all available cycles for the entire scan. For each cycle, the absolute cycle start time and the relative cycle start time are displayed. The relative cycle start time is given in brackets. By selecting/deselecting the respective checkboxes, you can include or exclude a cycle from scanning. Please note: ​Excluded cycles/scans cannot be reconstructed. The first and the last cycle cannot be excluded from the exposure pattern  The selected changes may influence other parameters that cannot be directly adjusted by the user, for example the number of cycles or the cycle time. Number of cycles The number of cycles depends on the cycle time and the scan time. The number of cycles can only be changed by adjusting the scan time. Cycle time The cycle time defines the total time needed for one cycle including table feed. The cycle time is adjusted depending on the pitch and the set scan length. Use Dose Reduction Technologies   For Flex 4D Spiral, the following dose reduction technologies help you to apply the optimal dose for each patient: CARE kV is a fully automated feature that adjusts the tube voltage tailored to the individual patient, the system capabilities, and the clinical task. If CARE kV is turned on, the system automatically adjusts the appropriate kV and effective mAs settings to optimize the applied dose while the image quality, technically defined as the contrast-to-noise ratio, is maintained. CARE kV is switched on by default for a Flex 4D Spiral examination. CARE Dose4D automatically adapts the tube current to the patient's body size and shape. Using the patient's topogram, CARE Dose4D evaluates an average dose for the complete scan. Reconstruction Images that have been acquired with Flex 4D Spiral can only be reconstructed fix axial. The number of recons depends on the acquired cycles (exposure pattern).   From the Reconstruction Pattern tab, you can deselect single cycles from the reconstruction by unticking the respective checkbox.   Please note: Cycles that have been excluded from the acquisition cannot be reconstructed. For Flex 4D Spiral, the following reconstruction aids are available: FAST Planning Iterative beam hardening correction (iBHC) Iterative metal artifact reduction (iMAR)   After successful completion of this course, you will be able to:  Understand the concept of Flex 4D Spiral and know the most common use cases Know the available scan modes  Understand the relationship between pitch, scan time and scan length Adjust scan parameters and cycle patterns Use the available Dose Reduction Technologies Change the recon pattern   Flex 4D Spiral is a feature available for CT Imaging that allows for the acquisition of dynamic data beyond the physical size of the detector width. This is achieved by the table that continuously moves forward and backward during the spiral scan with high accuracy.   4D imaging adds functional information to morphology and is used for the assessment of  Neuro perfusion (stroke)  Body perfusion (for example liver perfusion)  Dynamic angio (for example cerebral vasculature)  ​Image information:  Stroke assessment with Brain Perfusion acquired with Flex 4D Spiral at 70 kV  Courtesy of University Hospital Erlangen, Erlangen, Germany Depending on your SOMATOM scanner, the following Flex 4D Spiral scan modes may be available:    Scan modes Scan protocols (factory) Flex 4D Spiral (Neuro)  Dynamic Spiral Adult Head Brain Perfusion Brain Perfusion prolonged Dynamic Spiral Adult Head Angio Dynamic CTA Brain  Flex 4D Spiral (Body)  Dynamic Spiral Adult Body Liver Perfusion  Dynamic Spiral Adult Body Angio Thorax Dynamic CTA Extremity Dynamic CTA Brain Perfusion prolonged Learn more about the Brain Perfusion prolonged scan protocol. Neuro Perfusion prolonged is a CT Neuro Perfusion protocol with an extended image acquisition time (max. 120 s) for use in certain third party postprocessing solutions.  For further details, please contact your local application specialist.  SOMATOM Family - Scan Lengths Learn more about the scan lengths of the SOMATOM family. Depending on the selected scan mode, the following scan lengths* are available:      go.All go.Top X.cite go.Sim go.OpenPro Neuro perfusion 8.5 cm 8.5 cm 10 cm 8 cm 8 cm Body perfusion 11.5 cm 18.5 cm 19.5 cm n/a 9.5 cm Dynamic angio head/neck n/a 26.5 cm 28.5 cm n/a 25.5 cm Dynamic angio body n/a 40.5 cm 44 cm n/a n/a *The scan length numbers are given in steps of 0.5 cm to improve readability. The actual realized numbers at your SOMATOM CT system might therefore be slightly different.  For a Flex 4D Spiral workflow, the following scan parameters can be adjusted:  Scan time Scan length Pitch (depending on selected scan mode)  Exposure pattern  ​The selected changes may influence other parameters that cannot be directly adjusted by the user, for example, the number of cycles or the cycle time. Click the popup below to learn more about the correlation between the scan parameters and available scan lengths for different CT systems.  Adjusting scan parameters Learn more about adjusting the scan parameters. Tab TitleTextScan time The scan time is the summation of the cycle time and can be adapted. Adjusting the scan time only and leaving all other parameters the same, will lead to a changed number of cycles.  For example:  Brain Perfusion examination, cycle time 1.57, pitch 0.5   Scan time Number of cycles 25 s 15 46.9 s 29    Scan length The scan length is defined by the planned scan length in the topogram. For a Flex 4D Spiral examination, the maximum scan length is not determined by the physical detector width, but rather by the pitch and the required temporal resolution, for example, cycle time.  For example:  Dynamic CTA Extremity, cycle time 3.00    Pitch Scan length 1.0 x cm 1.5 y cm     Pitch The pitch is a dimensionless acquisition parameter in spiral computed tomography and describes the relation of patient table feed and beam collimation. Depending on the selected scan mode, the standard values for the pitch are:    Neuro Perfusion 0.5 Body Perfusion 0.5 or 1.0 Dynamic Angio head/neck 1 or 1.5 The pitch settings influence the cycle time and the maximum scan length.     Exposure Pattern In the Exposure Pattern, it is defined which cycles of the entire scan are to be acquired (exposed) during the examination.  In the Exposure Pattern list, you can see all available cycles for the entire scan. For each cycle, the absolute cycle start time and the relative cycle start time are displayed. The relative cycle start time is given in brackets.  By selecting/deselecting the respective checkboxes, you can include or exclude a cycle from scanning.  Please note: Excluded cycles cannot be reconstructed.  The first and the last cycle cannot be excluded from the exposure pattern. In the timeline, a box inside the scan length indicates a cycle/scan. To differentiate between an included and excluded cycle/scan, the color saturation of an excluded cycle/scan is lower than of an included cycle/scan.     Number of cycles The number of cycles depends on the cycle time and the scan time. The number of cycles can only be changed by adjusting the scan time. Example 1:  Scan time 24.96 s  Cycles 15 Example 2:  Scan time 46.94 s Cycles 29   Cycle time The cycle time defines the total time needed for one cycle including table feed.  The cycle time is adjusted depending on the pitch and the set scan length. Example 1: Pitch 1.00 Cycle time 3.00 Scan length 29.42 cm Cycles 13 Example 2: Pitch 1.00 Cycle time 2.00 Scan length 16.62 cm Cycles 20 Images that have been acquired with Flex 4D Spiral can only be reconstructed fix axial.  FAST Planning is available for Flex 4D Spiral.  Also, the following image impression parameters are available:  Iterative beam hardening correction (iBHC) Iterative metal artifact reduction (iMAR)  ​Click the popup below to learn about recon patterns.  Recon Pattern Learn about recon patterns. The number of recons depends on the acquired cycles (exposure pattern). Please note: Cycles that have been excluded from the acquisition cannot be reconstructed.  From the Reconstruction Pattern tab, you can deselect single cycles from the reconstruction by unticking the respective checkbox.  It is also possible to reconstruct thin slices from a single cycle depending on your clinical needs, for example, arterial phase for vascular analysis or portovenous phase for liver analysis. For Flex 4D Spiral, the following dose reduction technologies help you to apply the optimal dose for each patient:  CARE kV CARE Dose4D Click the popup below to learn more about CARE kV and CARE Dose4D.  Dose Reduction Technologies Learn more about CARE kV and CARE Dose4D. Tab TitleTextCARE kV CARE kV is a fully automated feature that adjusts the tube voltage tailored to the individual patient, the system capabilities, and the clinical task. If CARE kV is turned on, the system automatically adjusts the appropriate kV and effective mAs settings to optimize the applied dose while the image quality, technically defined as the contrast-to-noise ratio, is maintained. CARE kV is switched on by default for a Flex 4D Spiral examination. CARE Dose4D CARE Dose4D automatically adapts the tube current to the patient's body size and shape. Using the patient's topogram, CARE Dose4D evaluates an average current for the complete scan.    After reading the disclaimer, please proceed to the final quiz to complete the online training.  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 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 described in the material (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, 2020