SOMATOM Drive System Owner Manual Dosimetry and imaging performance report

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1 SOMATOM Drive System Owner Manual Dosimetry and imaging performance report

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3 Table of contents 1 Dosimetry and imaging performance report Dose information General information about dose indication Phantoms and methods Typical CT conditions of operation CTDI 100 for typical CT conditions of operation Dose factors related to the CTDI 100 for typical CT conditions of operation (128-slice) Overview of CTDI 100 (mgy/100 mas) CTDI free air Stray radiation Dose levels causing deterministic radiation effects Tolerances for CTDI Conversion factor for CTDI vol from Ø 32 cm phantom to Ø 16 cm phantom Conversion factor for CTDI vol CTDI vol for topograms Geometric efficiency in the z-direction Dose profiles Nominal values and tolerances for acceptance testing Beam quality, leakage technique factors and minimum filtration Performance specification of automatic exposure controls Use of radiation shields for the purpose of reducing patient dose in CT scanning with Siemens Healthcare CT systems Image quality Low-contrast detectability CT number Uniformity Image noise High-Contrast-Resolution, Modulation Transfer Function (MTF) Sensitivity profiles HD FOV: Advanced extended FOV reconstruction Nominal tomographic section thicknesses Information about quality assurance Test methods for the constancy tests 44 Index 47 SOMATOM Drive 3

4 Table of contents 4 Dosimetry and imaging performance report System Owner Manual

5 Dosimetry and imaging performance report 1 1 Dosimetry and imaging performance report This chapter provides dose and imaging performance data. The data are in accordance with the US code of federal regulations 21 CFR (c) and the International Electrotechnical Commission IEC standard. This chapter provides the following information: CTDI 100 for typical CT conditions of operation with regard to typical modes Dose factors showing the relative changes in CTDI 100 compared to the CTDI 100 of the typical mode, in varying a scan parameter Dosimetry data, such as beam quality, dose profiles, and stray radiation tables Image noise and High-Contrast-Resolution (HCR) of the typical modes Homogeneity of CT values and low-contrast resolution Reconstructable slice thicknesses Dose information General information about dose indication The CT system provides information about the CTDI vol and Dose Length Product (DLP) as defined by the IEC standard. Both values are displayed on the user interface of the scanner before and after each scan range. In addition, these values are stored in the Patient Protocol and the DICOM Structured Dose Report. The CTDI vol represents the average energy dose (expressed as Air KERMA) within a cylindrical PMMA phantom, aligned with the scanner axis and centered in the scan plane. The phantom diameter to which the displayed CTDI vol refers depends on the default application of the used protocol; see ( Page 9 CTDI 100 for typical CT conditions of operation). The reported and displayed CTDI vol and DLP refers to the 16 cm CTDI-phantom for head scans and to the 32 cm CTDI phantom for body scans, whereby the classification to 'head' or 'body' depends on the class of the original protocol delivered with the system. Neck protocols are classified as 'body'. CTDI vol and DLP of protocols originally intended for pediatric body examination and for neck examination refer to the 32 cm phantom. Factors for conversion of the displayed CTDIvol and DLP for the 32 cm phantom to equivalent CTDIvol and DLP for the 16 cm phantom are stated in ( Page 23 Conversion factor for CTDI vol from Ø 32 cm phantom to Ø 16 cm phantom) (child protocols are recommended for pediatric patients under the age of 12 years and with a normal body size). The CTDI values given in this manual are valid for deactivated CARE Dose 4D and CARE kv, as both features are not adapted to phantom measurements. Dynamic collimation (Adaptive Dose Shield) which reduces the dose of spiral overscan is taken into account for the reported DLP but not for the reported CTDI vol. SOMATOM Drive 5

6 1 Dosimetry and imaging performance report Further information regarding dose reduction functions is provided in the SOMATOM Instructions for Use. The reported DLP for spiral scans is calculated from the CTDI vol multiplied with a length L. The length L represents the table travel during the exposure and is corrected for effects of the dynamic collimation (Adaptive Dose Shield) which reduces the dose of spiral overscan. The reduction of DLP by the dynamic collimation is calculated as the time weighted average of collimator during the scan, divided by the nominal collimator opening for the scan. The effect of the dynamic collimation therefore is taken into account for the reported DLP but not for the reported CTDI vol. If the tube current varies during a scan, e.g. when using CARE Dose 4D, the CTDI vol and DLP displayed is the time-weighted average over the scan range Phantoms and methods According to: 21 CFR This chapter describes both, phantoms and methods used to establish the dose values reported below, and an instruction how to measure and determine CTDI vol, in order to verify against the value displayed at the scanner. The phantoms used to measure the CTDI values are circular cylinders of PMMA of diameter 16 cm (for head applications) or 32 cm (for all body applications), and with a length of at least 14 cm. They contain holes parallel to the axis of the phantom (A E) to hold 100 mm dose chambers. Phantoms are aligned with the scanner axis and centered in the scan field. A dose chamber with an active length of 100 mm is used for the dose measurements. All dose values are given in Air KERMA. CTDI 100 is measured in the center (A) and peripheral drillings at the 3 o clock, 6 o clock, 9 o clock and 12 o clock positions (B E). CTDI 100 locations in dosimetry phantoms with the line of sight towards the front side of the gantry To ensure correct dose measurements, it is recommended that a dosimeter conforming to IEC be used. The dosimeter has to be calibrated with beam qualities suitable for the CT energy spectrum examined, e.g. CT beam qualities "RQT" according IEC For dose measurements at 70 kv tube voltage or with tin filtration, an additional calibration with suitable beam qualities (for example RQR 5 acc. IEC and N150 acc. ISO 4037) is recommended to ensure that the energy dependance of the dosimeter does not distort the results of the dose measurements. 6 Dosimetry and imaging performance report System Owner Manual

7 Dosimetry and imaging performance report 1 The dose is measured in single axial scans, so that the dose chamber measures the integrated dose profile along the z-direction over 10 cm, in the center of the scan plane. The measured values should be large compared to the accuracy of the dosemeter. As a result, it might be necessary to select either a large tube current and exposure time or to average the dosimeter readings over several scans. For measurements with the dose chamber in one of the peripheral positions it is recommended to average the results over several scans. Otherwise the scan start angle of the individual scans may influence the result. IEC 61674: 2012 'Medical electrical equipment Dosimeters with ionization chambers and/or semiconductor detectors as used in X-ray diagnostic imaging' IEC 61267: 2005 'Radiation conditions for use in the determination of characteristics' ISO : 2004 'X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy' To calculate the CTDI 100 from the dosimeter readings (usually displayed as dose integrated over z-direction, i.e. as Dose Length Product (DLP), e.g. in mgy cm) the value has to be divided by the nominal beam collimation. For scan modes without a z-flying focal spot, the nominal beam collimation is equal to the acquisition displayed at the scanner's console (e.g. 'Acquisition mm' = 1.92 cm). For scan modes with a z-flying focal spot, the nominal beam collimation is equal to half of the acquisition displayed on the scanner's console (e.g. 'Acquisition mm' 0.5 = mm = 3.84 cm). ( Page 40 Nominal tomographic section thicknesses) LDP measured Length-Dose-Product [mgy cm] Note that the reading may also be displayed as dose averaged over the chamber length, e.g. in mgy. NxT Nominal Beam Collimation [cm] This is valid for all nominal beam collimations 4 cm. The CTDI w is the sum of a third of the CTDI 100 measured in the phantom's central chamber position (CTDI 100c ) and two third of the average of CTDI 100 measured in the phantom's four peripheral chamber position (CTDI 100p ). According to it's definition, CTDI w has to be derived from CTDI 100 measured in single axial scans. In this situation the CTDI vol is equal to the CTDI w. In general the CTDI vol displayed is derived from the CTDI w by multiplication with a factor that takes into account the table feed during scanning: SOMATOM Drive 7

8 1 Dosimetry and imaging performance report For spiral scanning For axial scanning For axial scanning without table feed For scanning with periodic back and forth table movement p Pitch factor NxT Nominal collimation n Number of scans v f Table feed per scan R Table range Typical CT conditions of operation According to: 21 CFR The following table provides scan parameter settings for typical modes of operation based on default setting of the Siemens scan protocols (with deactivated CARE Dose 4D and CARE kv). Protocol descriptions are provided by the Workflow Assistant. The system provides two shaped Xray beam filter settings (narrow, standard). These are set depending on the protocol type selected. The scan parameter settings provided here, although typical, may slightly deviate from the default protocols provided with the scanner software. Application type Typical head Typical head perfusion Typical body Typical cardiac Typical body Patient type Adult Adult Adult Adult Child Scan type Sequence Multiscan Spiral Sequence Spiral Protocol name HeadNeuroSeq NeuroPCT Abdomen Routine_IR DS_Coronary CTA_Adapt_Seq_IR* Abdomen Routine_IR Tube voltage 120 kv 80 kv 120 kv A, B: 100 kv, 100 kv 100 kv Tube mode Single Tube (A) Single Tube (A) Single Tube (A) Dual Tube (AB) Single Tube (A) Shaped filter A: Standard A: Standard A: Standard A, B: Narrow A: Narrow Tube current time product 390 mas 200 mas 147 eff. mas 250 mas/rot 98 eff. mas Tube current (per tube) 195 ma 200 ma 176 ma 439 ma 274 ma Rotation time 1.00 s 1.00 s 0.50 s s 0.50 s Number of scans Scan time 2.0 s 40 s 5.2 s 0.16 s 2.5 s Table range 112 mm 0 mm 237 mm 104 mm 268 mm Pitch factor or table feed 14.0 mm feed 0 mm feed 0.6 pitch 34.5 mm feed 1.4 pitch Collimation mm mm mm mm mm Data acquisition mm mm mm mm mm Total collimation 14.4 mm 38.4 mm 38.4 mm 38.4 mm 38.4 mm z-sharp off off on on off Reconstructed slice width 4.8 mm 5.0 mm 5.0 mm 3.0 mm 5.0 mm *) Flex 0.28 s, trigger: scan 70 to 70, pulsing off, 60 bpm, best phase manual, phase start 70 % 8 Dosimetry and imaging performance report System Owner Manual

9 Dosimetry and imaging performance report 1 Application type Typical head Typical head perfusion Typical body Typical cardiac Typical body Patient type Adult Adult Adult Adult Child Scan type Sequence Multiscan Spiral Sequence Spiral Kernel H31s H30s B30f B30f B30f *) Flex 0.28 s, trigger: scan 70 to 70, pulsing off, 60 bpm, best phase manual, phase start 70 % Typical CT conditions of operation CTDI 100 for typical CT conditions of operation According to: 21 CFR The following table indicates the CTDI for the protocols specified. There is no significant difference in the exposure of the peripheral chamber positions. The stated dose chamber positions are B - E according to their positions in the phantom (up, down, left, and right). ( Page 8 Typical CT conditions of operation) Application type Typical Head Typical Head Typical Body Typical Cardiac Typical Body Perfusion Patient size Adult Adult Adult Adult Child CTDI phantom Ø 16 cm Ø 16 cm Ø 32 cm Ø 32 cm Ø 32 cm CTDI 100 (mgy) per scan per scan per rotation per scan* per rotation Chamber position A (central) 62.8 mgy 331 mgy 3.66 mgy 3.76 mgy 2.90 mgy Chamber position B (Up) 64.0 mgy 347 mgy 6.76 mgy 6.3 mgy** 4.92 mgy Chamber position C (down) 65.4 mgy 354 mgy 6.41 mgy 6.1 mgy** 4.73 mgy Chamber position D (left) 63.5 mgy 342 mgy 6.64 mgy 6.2 mgy** 4.85 mgy Chamber position E (right) 63.3 mgy 341 mgy 6.67 mgy 6.3 mgy** 4.87 mgy Average peripheral 64.0 mgy 346 mgy 6.6 mgy 6.2 mgy 4.85 mgy CTDI W 63.6 mgy 341 mgy 5.63 mgy 5.4 mgy 4.20 mgy CTDI vol 65.5 mgy 341 mgy 9.4 mgy 6.01 mgy 3.00 mgy *) 0.33s full scan without pulsing **) Average over several partial scans CTDI 100 for typical CT conditions of operation CTDI vol and CTDI w are calculated values based on the measured CTDI 100, where the CTDI 100 has to be measured in axial scans (according to their definition in IEC ). As typical modes may be spiral scans, the values of CTDI 100 stated above are measured in axial scans with the same scan parameters (kv, ma, collimation, rotation time and filter) as used in the spiral mode General information Dose factors related to the CTDI 100 for typical CT conditions of operation (128-slice) According to: 21 CFR SOMATOM Drive 9

10 1 Dosimetry and imaging performance report The CTDI 100 is influenced by the following selectable scan parameters: kv Acquisition Shaped filter mas values (mas, eff. mas, mas/rot, ref. mas, ref. mas/rot) The CTDI 100 is not influenced by the rotation time or recon parameters, such as Kernel or FoV. In the following tables, the CTDI 100 for the typical mode is represented by the value 1.00, shown in bold. CTDI 100 for varying scan parameters are given as a proportion of the CTDI 100 for the typical mode. Dose factors are presented for a wide range of scan parameter combinations that influence dose. However, depending on system configuration, licences and available scan protocols, not all of the combinations shown may be selectable. CTDI 100 dose factors for varying tube voltage and shaped filter Values are given for central and peripheral CTDI 100 and are expressed as a proportion of the CTDI 100 for the typical mode, shown in bold. Sn 100 kv 140 kv 130 kv 120 kv 110 kv 100 kv 90 kv 80 kv 70 kv* Tube voltage Typical Head Typical Head Perfusion Typical Body CTDI Phantom Ø 16 cm Shaped filter CTDI Phantom Ø 16 cm Shaped filter CTDI Phantom Ø 32cm Shaped filter Narrow Standard Narrow Standard Narrow Standard Central 0,17 0,18 n.a. 0,63 0,12 0,14 Peripheral 0,16 0,19 n.a. 0,64 0,13 0,17 Weighted 0,16 0,19 n.a. 0,63 0,13 0,16 Central 0,27 0,29 n.a. 1,00 0,22 0,25 Peripheral 0,25 0,30 n.a. 1,00 0,21 0,28 Weighted 0,26 0,30 n.a. 1,00 0,21 0,27 Central 0,40 0,43 n.a. 1,47 0,35 0,39 Peripheral 0,38 0,44 n.a. 1,46 0,33 0,42 Weighted 0,38 0,44 n.a. 1,46 0,33 0,42 Central 0,55 0,60 n.a. 2,03 0,50 0,56 Peripheral 0,52 0,60 n.a. 1,99 0,45 0,59 Weighted 0,53 0,60 n.a. 2,00 0,46 0,58 Central 0,74 0,80 n.a. 2,72 0,69 0,78 Peripheral 0,70 0,80 n.a. 2,66 0,61 0,79 Weighted 0,71 0,80 n.a. 2,68 0,63 0,79 Central 0,92 1,00 n.a. 3,40 0,89 1,00 Peripheral 0,87 1,00 n.a. 3,32 0,78 1,00 Weighted 0,89 1,00 n.a. 3,34 0,80 1,00 Central 1,12 1,21 n.a. 4,12 1,12 1,26 Peripheral 1,06 1,21 n.a. 4,02 0,97 1,24 Weighted 1,08 1,21 n.a. 4,05 1,00 1,24 Central 1,35 1,45 n.a. 4,93 1,38 1,54 Peripheral 1,28 1,45 n.a. 4,80 1,18 1,50 Weighted 1,30 1,45 n.a. 4,85 1,22 1,51 Central 0,10 0,11 n.a. 0,37 0,11 0,13 Peripheral 0,10 0,11 n.a. 0,36 0,09 0,12 Weighted 0,10 0,11 n.a. 0,36 0,10 0,12 10 Dosimetry and imaging performance report System Owner Manual

11 Dosimetry and imaging performance report 1 Sn140 kv Tube voltage Typical Head Typical Head Perfusion Typical Body CTDI Phantom Ø 16 cm Shaped filter CTDI Phantom Ø 16 cm Shaped filter CTDI Phantom Ø 32cm Shaped filter Narrow Standard Narrow Standard Narrow Standard Central 0,44 0,46 n.a. 1,58 0,53 0,58 Peripheral 0,42 0,46 n.a. 1,53 0,42 0,52 Weighted 0,43 0,46 n.a. 1,54 0,44 0,53 Dose Factors of CTDI 100 for variation of tube voltage and shaped filter for central / peripheral /weighted CTDI 100; each related to typical mode (bold) Sn140 kv* Sn 100 kv 140 kv 130 kv 120 kv 110 kv 100 kv 90 kv 80 kv 70 kv* Tube voltage Typical Cardiac Typical Pediatric Body CTDI Phantom Ø 32 cm Shaped filter CTDI Phantom Ø 32cm Shaped filter Narrow Standard Narrow Standard Central 0,24 n.a. 0,24 n.a. Peripheral 0,28 n.a. 0,28 n.a. Weighted 0,27 n.a. 0,27 n.a. Central 0,44 n.a. 0,43 n.a. Peripheral 0,47 n.a. 0,47 n.a. Weighted 0,46 n.a. 0,46 n.a. Central 0,69 n.a. 0,70 n.a. Peripheral 0,72 n.a. 0,72 n.a. Weighted 0,71 n.a. 0,71 n.a. Central 1,00 n.a. 1,00 n.a. Peripheral 1,00 n.a. 1,00 n.a. Weighted 1,00 n.a. 1,00 n.a. Central 1,39 n.a. 1,39 n.a. Peripheral 1,35 n.a. 1,35 n.a. Weighted 1,36 n.a. 1,36 n.a. Central 1,79 n.a. 1,79 n.a. Peripheral 1,71 n.a. 1,71 n.a. Weighted 1,73 n.a. 1,73 n.a. Central 2,25 n.a. 2,25 n.a. Peripheral 2,13 n.a. 2,13 n.a. Weighted 2,16 n.a. 2,15 n.a. Central 2,77 n.a. 2,77 n.a. Peripheral 2,59 n.a. 2,59 n.a. Weighted 2,63 n.a. 2,63 n.a. Central 0,23 n.a. 0,23 n.a. Peripheral 0,20 n.a. 0,20 n.a. Weighted 0,21 n.a. 0,21 n.a. Central 1,07 n.a. 1,06 n.a. Peripheral 0,93 n.a. 0,92 n.a. Weighted 0,96 n.a. 0,95 n.a. Dose Factors of CTDI 100 for variation of tube voltage and shaped filter for central / peripheral /weighted CTDI 100; each related to typical mode (bold) Dose factors for varying acquisition type Values are given for central and peripheral CTDI 100 and are expressed as a proportion of the typical mode CTDI 100, shown in bold. SOMATOM Drive 11

12 1 Dosimetry and imaging performance report Acquisition Collimation Typical Head Typical Head Perfusion Typical Body Typical Cardiac Typical Pediatric Body 2 x 1 mm 2 x 1 mm n.a. n.a n.a x 5 mm 1 x 5 mm 0.78 n.a n.a x 0.6 mm 10 x 0.6 mm 1.03 n.a n.a x 0.6 mm 8 x 0.6 mm 1.49 n.a n.a x 0.3 mm 8 x 0.6 mm 1.49 n.a n.a x 10 mm 1 x 10 mm 0.78 n.a n.a x 0.6 mm 20 x 0.6 mm 1.05 n.a n.a x 1.2 mm 12 x 1.2 mm 1.00 n.a n.a x 0.6 mm 32 x 0.6 mm 0.96 n.a x 0.6 mm 32 x 0.6 mm 0.98 n.a x 1.2 mm 32 x 1.2 mm x 0.6 mm 64 x 0.6 mm 0.86 n.a Dose factors for varying acquisition type Dose factors for varying mas Values are given for central and peripheral CTDI 100 and are expressed as a proportion of the typical mode CTDI 100, shown in bold. Dose factors are valid for deactivated CARE Dose 4D. Current* Typical Head Typical Head Perfusion Typical Body Typical Cardiac Typical Pediatric Body mas factor mas factor eff. mas factor mas/rot factor eff. mas factor 20 ma ma ma ma ma ma ma , , , , , ma ,77 n.a. n.a , , , ma n.a. n.a. n.a. n.a , , , ma n.a. n.a. n.a. n.a. n.a. n.a ,82 n.a. n.a. *) per tube Dose Factors for variation of mas central and peripheral CTDI 100, related to typical mode (bold) Overview of CTDI 100 (mgy/100 mas) Not all combinations of mode parameters shown are selectable. For dual-source modes, separate calculations have to be done for Tube A and B. 12 Dosimetry and imaging performance report System Owner Manual

13 Dosimetry and imaging performance report 1 CTDI100 (mgy/100 mas) Collimation [mm] 2 x 1 6 x x x 5 10 x x x x x x x 0.6 Acquisition [mm] 16 x x x x 0.6 mm, 64 x 0.6 mm Filter (z-sharp) (z-sharp) (z-sharp) (z-sharp) (z-sharp) 128 x kv Tube Voltage CTDI100, central 2,57 4,17 4,39 2,31 3,04 2,31 2,96 3,10 2,86 2,59 2,52 CTDI100, peripheral 2,74 4,44 4,64 2,46 3,22 2,46 3,16 3,28 3,04 2,75 2,67 CTDIw 2,69 4,35 4,56 2,41 3,16 2,41 3,09 3,22 2,98 2,70 2,62 CTDI100, central 4,12 6,66 7,03 3,69 4,87 3,69 4,74 4,97 4,58 4,13 4,04 CTDI100, peripheral 4,30 6,97 7,30 3,86 5,06 3,86 4,95 5,16 4,77 4,32 4,20 CTDIw 4,24 6,87 7,21 3,80 5,00 3,80 4,88 5,10 4,71 4,26 4,15 90 kv 80 kv CTDI100, central 6,06 9,81 10,4 5,44 7,19 5,44 6,97 7,33 6,75 6,09 5,97 CTDI100, peripheral 6,26 10,1 10,6 5,62 7,38 5,62 7,21 7,52 6,95 6,29 6,12 CTDIw 6,20 10,0 10,6 5,56 7,32 5,56 7,13 7,46 6,89 6,22 6,07 CTDI100, central 8,35 13,5 14,3 7,49 9,91 7,49 9,60 10,1 9,30 8,38 8,22 CTDI100, peripheral 8,57 13,9 14,6 7,69 10,1 7,69 9,86 10,3 9,51 8,61 8,37 CTDIw 8,49 13,8 14,5 7,62 10,0 7,62 9,77 10,2 9,44 8,53 8, kv 100 kv CTDI100, central 11,2 18,1 19,2 10,1 13,3 10,1 12,9 13,5 12,5 11,3 11,0 CTDI100, peripheral 11,4 18,5 19,5 10,3 13,5 10,3 13,2 13,7 12,7 11,5 11,2 CTDIw 11,4 18,4 19,4 10,2 13,4 10,2 13,1 13,7 12,6 11,4 11,1 CTDI100, central 14,0 22,7 23,9 12,6 16,6 12,6 16,1 16,9 15,6 14,1 13,8 CTDI100, peripheral 14,3 23,1 24,3 12,8 16,8 12,8 16,4 17,1 15,8 14,3 13,9 CTDIw 14,2 23,0 24,1 12,7 16,7 12,7 16,3 17,1 15,8 14,2 13,9 130 kv 120 kv CTDI100, central 16,9 27,4 29,0 15,2 20,1 15,2 19,5 20,5 18,9 17,0 16,7 CTDI100, peripheral 17,3 28,0 29,4 15,5 20,4 15,5 19,9 20,8 19,2 17,4 16,9 CTDIw 17,2 27,8 29,3 15,4 20,3 15,4 19,8 20,7 19,1 17,3 16,8 CTDI100, central 20,3 32,9 34,8 18,2 24,1 18,2 23,4 24,6 22,6 20,4 20,0 CTDI100, peripheral 20,7 33,5 35,2 18,5 24,4 18,5 23,8 24,9 23,0 20,8 20,3 CTDIw 20,5 33,3 35,1 18,4 24,3 18,4 23,6 24,8 22,9 20,6 20,2 Sn 100 kv 140 kv CTDI100, central 1,54 2,50 2,65 1,38 1,84 1,38 1,77 1,87 1,72 1,55 1,52 CTDI100, peripheral 1,53 2,48 2,62 1,38 1,82 1,38 1,76 1,85 1,71 1,54 1,51 CTDIw 1,54 2,49 2,63 1,38 1,82 1,38 1,77 1,86 1,71 1,54 1,51 CTDI100, central 6,49 10,5 11,2 5,82 7,74 5,82 7,47 7,88 7,25 6,52 6,42 CTDI100, peripheral 6,58 10,6 11,3 5,90 7,81 5,90 7,57 7,97 7,33 6,61 6,48 CTDIw 6,55 10,6 11,2 5,87 7,79 5,87 7,54 7,94 7,30 6,58 6,46 Sn 140 kv Phantom: Ø 16 cm; Shaped Filter: Standard; Typical Application: Head SOMATOM Drive 13

14 1 Dosimetry and imaging performance report Collimation [mm] 2 x 1 6 x x x 5 10 x x x x x x x 0.6 Acquisition [mm] 16 x x x x 0.6 mm, 64 x 0.6 mm Filter (z-sharp) (z-sharp) (z-sharp) (z-sharp) (z-sharp) 128 x kv Tube Voltage CTDI100, central 2,32 3,75 3,95 2,08 2,74 2,08 2,67 2,79 2,58 2,33 2,27 CTDI100, peripheral 2,28 3,69 3,85 2,05 2,67 2,05 2,62 2,72 2,52 2,29 2,21 CTDIw 2,29 3,71 3,88 2,06 2,69 2,06 2,64 2,74 2,54 2,30 2,23 CTDI100, central 3,74 6,05 6,38 3,35 4,43 3,35 4,30 4,51 4,16 3,76 3,67 CTDI100, peripheral 3,63 5,88 6,15 3,26 4,26 3,26 4,18 4,34 4,02 3,65 3,54 CTDIw 3,67 5,94 6,23 3,29 4,32 3,29 4,22 4,40 4,07 3,68 3,58 90 kv 80 kv CTDI100, central 5,54 8,97 9,47 4,97 6,57 4,97 6,38 6,69 6,17 5,56 5,45 CTDI100, peripheral 5,36 8,68 9,06 4,81 6,28 4,81 6,17 6,41 5,93 5,38 5,21 CTDIw 5,42 8,77 9,20 4,86 6,38 4,86 6,24 6,50 6,01 5,44 5,29 CTDI100, central 7,66 12,4 13,1 6,87 9,08 6,87 8,81 9,25 8,53 7,69 7,53 CTDI100, peripheral 7,39 12,0 12,5 6,63 8,67 6,63 8,50 8,84 8,18 7,42 7,19 CTDIw 7,48 12,1 12,7 6,71 8,81 6,71 8,60 8,98 8,30 7,51 7, kv 100 kv CTDI100, central 10,3 16,7 17,6 9,26 12,2 9,26 11,9 12,5 11,5 10,4 10,1 CTDI100, peripheral 9,94 16,1 16,8 8,92 11,7 8,92 11,4 11,9 11,0 9,99 9,68 CTDIw 10,1 16,3 17,1 9,03 11,9 9,03 11,6 12,1 11,2 10,1 9,83 CTDI100, central 12,9 20,9 22,1 11,6 15,3 11,6 14,9 15,6 14,4 13,0 12,7 CTDI100, peripheral 12,5 20,2 21,1 11,2 14,6 11,2 14,3 14,9 13,8 12,5 12,1 CTDIw 12,6 20,4 21,4 11,3 14,9 11,3 14,5 15,1 14,0 12,7 12,3 130 kv 120 kv CTDI100, central 15,7 25,4 26,8 14,1 18,6 14,1 18,1 19,0 17,5 15,8 15,4 CTDI100, peripheral 15,2 24,6 25,8 13,6 17,9 13,6 17,5 18,2 16,8 15,3 14,8 CTDIw 15,4 24,9 26,1 13,8 18,1 13,8 17,7 18,5 17,1 15,4 15,0 CTDI100, central 18,8 30,5 32,3 16,9 22,4 16,9 21,7 22,8 21,0 18,9 18,5 CTDI100, peripheral 18,2 29,5 31,0 16,3 21,5 16,3 21,0 21,9 20,2 18,3 17,8 CTDIw 18,4 29,8 31,4 16,5 21,8 16,5 21,2 22,2 20,5 18,5 18,0 Sn 100 kv 140 kv CTDI100, central 1,45 2,35 2,49 1,30 1,73 1,30 1,67 1,76 1,62 1,46 1,43 CTDI100, peripheral 1,38 2,23 2,35 1,24 1,63 1,24 1,59 1,66 1,53 1,38 1,35 CTDIw 1,40 2,27 2,40 1,26 1,66 1,26 1,61 1,69 1,56 1,41 1,38 CTDI100, central 6,16 9,97 10,6 5,52 7,35 5,52 7,09 7,49 6,88 6,19 6,09 CTDI100, peripheral 6,00 9,72 10,3 5,39 7,12 5,39 6,91 7,26 6,69 6,03 5,91 CTDIw 6,06 9,80 10,4 5,43 7,20 5,43 6,97 7,34 6,75 6,08 5,97 Sn 140 kv Phantom: Ø 16 cm; Shaped Filter: Narrow; Typical Application: Inner Ear 14 Dosimetry and imaging performance report System Owner Manual

15 Dosimetry and imaging performance report 1 Collimation [mm] 2 x 1 6 x x x 5 10 x x x x x x x 0.6 Acquisition [mm] 16 x x x x 0.6 mm, 64 x 0.6 mm Filter (z-sharp) (z-sharp) (z-sharp) (z-sharp) (z-sharp) 128 x kv Tube Voltage CTDI100, central 0,58 0,94 0,99 0,52 0,69 0,52 0,66 0,70 0,64 0,58 0,57 CTDI100, peripheral 1,29 2,08 2,20 1,15 1,52 1,15 1,48 1,55 1,43 1,29 1,26 CTDIw 1,05 1,70 1,79 0,94 1,24 0,94 1,21 1,27 1,17 1,05 1,03 CTDI100, central 1,04 1,69 1,79 0,94 1,24 0,94 1,20 1,26 1,16 1,05 1,03 CTDI100, peripheral 2,16 3,50 3,67 1,94 2,55 1,94 2,49 2,59 2,40 2,17 2,11 CTDIw 1,79 2,90 3,04 1,60 2,11 1,60 2,06 2,15 1,99 1,80 1,75 90 kv 80 kv CTDI100, central 1,66 2,68 2,84 1,49 1,97 1,49 1,91 2,00 1,85 1,66 1,63 CTDI100, peripheral 3,27 5,30 5,55 2,93 3,85 2,93 3,76 3,92 3,63 3,29 3,19 CTDIw 2,73 4,42 4,64 2,45 3,22 2,45 3,14 3,28 3,03 2,74 2,67 CTDI100, central 2,38 3,85 4,07 2,13 2,82 2,13 2,73 2,88 2,65 2,39 2,34 CTDI100, peripheral 4,53 7,34 7,69 4,06 5,33 4,06 5,21 5,43 5,03 4,55 4,42 CTDIw 3,81 6,17 6,48 3,42 4,50 3,42 4,39 4,58 4,23 3,83 3, kv 100 kv CTDI100, central 3,28 5,31 5,62 2,94 3,90 2,94 3,77 3,97 3,66 3,29 3,23 CTDI100, peripheral 6,10 9,88 10,35 5,47 7,17 5,47 7,02 7,31 6,77 6,13 5,95 CTDIw 5,16 8,36 8,77 4,63 6,08 4,63 5,94 6,20 5,73 5,18 5,04 CTDI100, central 4,22 6,84 7,23 3,79 5,01 3,79 4,86 5,11 4,70 4,24 4,16 CTDI100, peripheral 7,69 12,4 13,1 6,90 9,05 6,90 8,85 9,22 8,53 7,72 7,50 CTDIw 6,53 10,6 11,1 5,86 7,70 5,86 7,52 7,85 7,25 6,56 6, kv 120 kv CTDI100, central 5,29 8,57 9,07 4,75 6,29 4,75 6,09 6,41 5,90 5,31 5,22 CTDI100, peripheral 9,50 15,4 16,1 8,52 11,2 8,52 10,9 11,4 10,5 9,54 9,28 CTDIw 8,10 13,1 13,8 7,26 9,55 7,26 9,32 9,74 8,99 8,13 7,92 CTDI100, central 6,49 10,5 11,1 5,82 7,72 5,82 7,47 7,86 7,24 6,52 6,40 CTDI100, peripheral 11,5 18,6 19,6 10,3 13,6 10,3 13,3 13,8 12,8 11,6 11,2 CTDIw 9,84 15,9 16,7 8,83 11,6 8,83 11,3 11,8 10,9 9,89 9,63 Sn 100 kv 140 kv CTDI100, central 0,54 0,87 0,92 0,48 0,64 0,48 0,62 0,65 0,60 0,54 0,53 CTDI100, peripheral 0,89 1,44 1,52 0,80 1,05 0,80 1,02 1,07 0,99 0,89 0,87 CTDIw 0,77 1,25 1,32 0,69 0,91 0,69 0,89 0,93 0,86 0,78 0,76 CTDI100, central 2,45 3,97 4,21 2,20 2,92 2,20 2,82 2,97 2,73 2,46 2,42 CTDI100, peripheral 3,98 6,45 6,81 3,57 4,72 3,57 4,59 4,81 4,44 4,00 3,91 CTDIw 3,47 5,62 5,94 3,12 4,12 3,12 4,00 4,20 3,87 3,49 3,42 Sn 140 kv Phantom: Ø 32 cm; Shaped Filter: Standard; Typical Application: Adult Body SOMATOM Drive 15

16 1 Dosimetry and imaging performance report Collimation [mm] 2 x 1 6 x x x 5 10 x x x x x x x 0.6 Acquisition [mm] 16 x x x x 0.6 mm, 64 x 0.6 mm Filter (z-sharp) (z-sharp) (z-sharp) (z-sharp) (z-sharp) 128 x kv Tube Voltage CTDI100, central 0,50 0,81 0,86 0,45 0,60 0,45 0,58 0,61 0,56 0,50 0,49 CTDI100, peripheral 0,98 1,58 1,66 0,88 1,15 0,88 1,13 1,17 1,08 0,98 0,95 CTDIw 0,82 1,33 1,39 0,74 0,97 0,74 0,94 0,98 0,91 0,82 0,80 CTDI100, central 0,91 1,48 1,56 0,82 1,08 0,82 1,05 1,11 1,02 0,92 0,90 CTDI100, peripheral 1,65 2,68 2,79 1,48 1,94 1,48 1,90 1,97 1,83 1,66 1,61 CTDIw 1,41 2,28 2,38 1,26 1,65 1,26 1,62 1,68 1,56 1,41 1,37 90 kv 80 kv CTDI100, central 1,46 2,36 2,49 1,31 1,73 1,31 1,68 1,76 1,62 1,47 1,43 CTDI100, peripheral 2,52 4,09 4,26 2,26 2,95 2,26 2,90 3,01 2,79 2,53 2,45 CTDIw 2,17 3,51 3,67 1,95 2,54 1,95 2,50 2,59 2,40 2,18 2,11 CTDI100, central 2,10 3,40 3,59 1,89 2,49 1,89 2,42 2,54 2,34 2,11 2,07 CTDI100, peripheral 3,52 5,69 5,93 3,15 4,11 3,15 4,05 4,19 3,89 3,53 3,41 CTDIw 3,04 4,93 5,15 2,73 3,57 2,73 3,50 3,64 3,37 3,06 2, kv 100 kv CTDI100, central 2,91 4,72 4,98 2,61 3,45 2,61 3,35 3,52 3,24 2,93 2,86 CTDI100, peripheral 4,75 7,69 8,02 4,26 5,56 4,26 5,47 5,67 5,26 4,77 4,61 CTDIw 4,14 6,70 7,01 3,71 4,86 3,71 4,76 4,95 4,59 4,16 4,03 CTDI100, central 3,76 6,09 6,42 3,37 4,45 3,37 4,33 4,54 4,18 3,78 3,69 CTDI100, peripheral 6,03 9,76 10,2 5,41 7,05 5,41 6,93 7,18 6,66 6,05 5,84 CTDIw 5,27 8,53 8,92 4,73 6,18 4,73 6,06 6,30 5,84 5,29 5, kv 120 kv CTDI100, central 4,73 7,65 8,08 4,24 5,60 4,24 5,44 5,71 5,26 4,75 4,65 CTDI100, peripheral 7,48 12,1 12,6 6,71 8,76 6,71 8,60 8,93 8,28 7,51 7,27 CTDIw 6,56 10,6 11,1 5,88 7,71 5,88 7,55 7,86 7,27 6,59 6,39 CTDI100, central 5,81 9,41 9,96 5,21 6,90 5,21 6,69 7,04 6,48 5,84 5,72 CTDI100, peripheral 9,10 14,7 15,4 8,16 10,7 8,16 10,5 10,9 10,1 9,14 8,84 CTDIw 8,00 13,0 13,6 7,18 9,40 7,18 9,21 9,58 8,87 8,04 7,80 Sn 100 kv 140 kv CTDI100, central 0,48 0,78 0,82 0,43 0,57 0,43 0,55 0,58 0,54 0,48 0,47 CTDI100, peripheral 0,71 1,15 1,20 0,64 0,83 0,64 0,82 0,85 0,79 0,71 0,69 CTDIw 0,63 1,02 1,08 0,57 0,75 0,57 0,73 0,76 0,70 0,64 0,62 CTDI100, central 2,23 3,61 3,83 2,00 2,66 2,00 2,57 2,71 2,49 2,24 2,20 CTDI100, peripheral 3,24 5,24 5,50 2,90 3,81 2,90 3,73 3,88 3,59 3,25 3,16 CTDIw 2,90 4,70 4,94 2,60 3,43 2,60 3,34 3,49 3,22 2,92 2,84 Sn 140 kv Phantom: Ø 32 cm; Shaped Filter: Narrow; Typical Application: Cardio, Pediatric Body, Flash (except Flash Trauma) 16 Dosimetry and imaging performance report System Owner Manual

17 Dosimetry and imaging performance report 1 Collimation [mm] 2 x 1 6 x x x 5 10 x x x x x x x 0.6 Acquisition [mm] 16 x x x x 0.6 mm, 64 x 0.6 mm Filter (z-sharp) (z-sharp) (z-sharp) (z-sharp) (z-sharp) 128 x kv Tube Voltage CTDI100, free air 4,48 7,25 7,65 4,02 5,30 4,02 5,16 5,40 4,98 4,50 4,40 CTDI100, free air 6,79 11,0 11,6 6,09 8,06 6,09 7,82 8,21 7,56 6,82 6,68 90 kv 80 kv CTDI100, free air 9,50 15,4 16,3 8,53 11,3 8,53 10,9 11,5 10,6 9,55 9,36 CTDI100, free air 12,5 20,3 21,5 11,3 14,9 11,3 14,4 15,2 14,0 12,6 12,4 110 kv 100 kv CTDI100, free air 16,3 26,3 27,8 14,6 19,3 14,6 18,7 19,7 18,1 16,3 16,0 CTDI100, free air 20,0 32,4 34,3 18,0 23,8 18,0 23,0 24,3 22,3 20,1 19,7 130 kv 120 kv CTDI100, free air 24,2 39,2 41,5 21,7 28,8 21,7 27,9 29,3 27,0 24,3 23,9 CTDI100, free air 28,9 46,7 49,5 25,9 34,3 25,9 33,2 35,0 32,2 29,0 28,5 Sn 100 kv 140 kv CTDI100, free air 2,00 3,23 3,44 1,79 2,39 1,79 2,30 2,43 2,23 2,01 1,98 CTDI100, free air 8,60 13,9 14,8 7,72 10,3 7,72 9,90 10,5 9,62 8,64 8,53 SN 140 kv Phantom: none; Shaped Filter: Standard; Application: n.a. Collimation [mm] 2 x 1 6 x x x 5 10 x x x x x x x 0.6 Acquisition [mm] 16 x x x x 0.6 mm, 64 x 0.6 mm Filter (z-sharp) (z-sharp) (z-sharp) (z-sharp) (z-sharp) 128 x kv Tube Voltage CTDI100, free air 4,12 6,68 7,05 3,70 4,89 3,70 4,75 4,98 4,59 4,14 4,06 CTDI100, free air 6,29 10,2 10,8 5,64 7,48 5,64 7,24 7,62 7,01 6,32 6,20 90 kv 80 kv CTDI100, free air 8,87 14,4 15,2 7,96 10,5 7,96 10,2 10,7 9,9 8,91 8,74 CTDI100, free air 11,8 19,0 20,1 10,6 14,0 10,6 13,5 14,2 13,1 11,8 11,6 110 kv 100 kv CTDI100, free air 15,3 24,7 26,2 13,7 18,2 13,7 17,6 18,5 17,0 15,3 15,1 Phantom: none; Shaped Filter: Narrow; Application: n.a. SOMATOM Drive 17

18 1 Dosimetry and imaging performance report Collimation [mm] 2 x 1 6 x x x 5 10 x x x x x x x 0.6 Acquisition [mm] 16 x x x x 0.6 mm, 64 x 0.6 mm Filter (z-sharp) (z-sharp) (z-sharp) (z-sharp) (z-sharp) 128 x kv Tube Voltage CTDI100, free air 18,9 30,6 32,4 16,9 22,5 16,9 21,7 22,9 21,1 19,0 18,6 CTDI100, free air 22,9 37,0 39,2 20,5 27,2 20,5 26,3 27,7 25,5 23,0 22,5 140 kv 130 kv CTDI100, free air 27,4 44,3 46,9 24,5 32,5 24,5 31,5 33,2 30,5 27,5 27,0 CTDI100, free air 1,92 3,11 3,31 1,72 2,30 1,72 2,21 2,34 2,15 1,93 1,91 SN 140 kv Sn 100 kv CTDI100, free air 8,34 13,5 14,4 7,48 10,0 7,48 9,60 10,2 9,32 8,38 8,27 Phantom: none; Shaped Filter: Narrow; Application: n.a. 18 Dosimetry and imaging performance report System Owner Manual

19 Dosimetry and imaging performance report CTDI free air The CTDI free air is stated in the following table based on the typical body mode (shown in bold type) for varying collimation, kv, and filter setting. Additionally, the CTDI free air for the typical head mode is stated. Acquisition [mm] Variation of the collimation 2 1 6x x x 5 20 x (typical) Total collimation [mm] 2.0 mm 3.6 mm 4.8 mm 5.0 mm 6.0 mm 10.0 mm 12.0 mm 14.4 mm 19.2 mm 19.2 mm 38.4 mm 38.4 mm 70 kv 6,6 10,7 11,2 5,9 7,8 5,9 7,9 7,6 7,3 7,4 6,6 6,5 80 kv 10,0 16,2 17,1 9,0 11,8 9,0 12,1 11,5 11,0 11,2 10,0 9,8 90 kv 14,0 22,6 23,9 12,5 16,6 12,5 16,9 16,1 15,4 15,8 14,0 13,8 100 kv 18,4 29,9 31,6 16,5 21,9 16,5 22,3 21,2 20,3 20,8 18,5 18,2 110 kv 23,9 38,7 40,9 21,4 28,4 21,4 28,9 27,5 26,3 26,9 24,0 23,5 120 kv (typical) 29,4 47,6 50,5 26,4 35,0 26,4 35,7 33,9 32,4 33,2 29,6 29,0 Shaped filter: Shaped filter: standard narrow 130 kv 35,6 57,6 61,0 31,9 42,3 31,9 43,1 41,0 39,2 40,2 35,7 35,1 140 kv 42,4 68,7 72,8 38,1 50,5 38,1 51,4 48,8 46,7 47,9 42,6 41,9 Sn 100 kv 2,9 4,8 5,1 2,6 3,5 2,6 3,6 3,4 3,2 3,3 2,9 2,9 Sn 140 kv 12,6 20,5 21,8 11,3 15,1 11,3 15,4 14,6 13,9 14,4 12,7 12,5 70 kv 6,1 9,8 10,4 5,4 7,2 5,4 7,3 7,0 6,7 6,8 6,1 6,0 80 kv 9,2 15,0 15,9 8,3 11,0 8,3 11,2 10,6 10,2 10,4 9,3 9,1 90 kv 13,0 21,1 22,3 11,7 15,5 11,7 15,8 15,0 14,4 14,7 13,1 12,8 100 kv 17,3 28,0 29,6 15,5 20,5 15,5 20,9 19,9 19,0 19,5 17,4 17,0 110 kv 22,5 36,4 38,5 20,2 26,7 20,2 27,2 25,8 24,7 25,3 22,6 22,1 120 kv 27,7 44,9 47,7 24,9 33,0 24,9 33,7 31,9 30,6 31,4 27,9 27,4 130 kv 33,6 54,4 57,6 30,1 40,0 30,1 40,7 38,7 37,0 38,0 33,8 33,1 140 kv 40,2 65,1 69,0 36,1 47,8 36,1 48,7 46,3 44,3 45,4 40,4 39,7 Sn 100 kv 2,8 4,6 4,9 2,5 3,4 2,5 3,4 3,3 3,1 3,2 2,8 2,8 Sn 140 kv 12,3 19,8 21,1 11,0 14,7 11,0 14,9 14,1 13,5 13,9 12,3 12,2 CTDI free air in mgy for typical body mode (bold type) with variation of collimation, kv, and filter setting Acquisition [mm] Total collimation [mm] 14.4 Shaped Filter Wide 120 kv (typical) 89,8 CTDI free air in mgy for setting of typical head mode Stray radiation Stray radiation is indicated for the horizontal and vertical planes based on the scanner coordinate system (intersection of scanner axis with scan plane) for maximum tube voltage (140 kv) and maximum collimation width ( mm). A cylindrical PMMA phantom with a diameter of 32 cm and a length of 15 cm is centered in the scan plane for the stray radiation measurement. A 500 cm 3 dose chamber is used for the measurements. SOMATOM Drive 19

20 1 Dosimetry and imaging performance report The accuracy of stated values is determined by the accuracy of chamber positioning (± 5 cm in each direction) and by the accuracy of the dosemeter (± 5% or µgy/mas, whichever is more). Backscatter from cabin walls or similar surfaces may cause additional variation in the radiation measurement. The data below represent the maximum scatter radiation for that system type. Depending on the system configuration, i.e. shaped filter or gantry cover, lower values may result. Data in the tables below are derived from measured values. Stray radiation in microgray (µgy) per mas Stray radiation (vertical) 20 Dosimetry and imaging performance report System Owner Manual

21 Dosimetry and imaging performance report 1 Stray radiation (horizontal) Dose levels causing deterministic radiation effects Certain modes of operation allow selections of scan parameters that may lead to an accumulated peripheral CTDI 100 of more than 1 Gy. This dose may exceed the threshold for deterministic radiation effects on the patient's skin or eye lenses (see IEC :2008, Annex A.2, ). SOMATOM Drive 21

22 1 Dosimetry and imaging performance report The accumulated peripheral CTDI 100 may serve as a very rough estimation of skin or eye lens dose. However, other factors may influence the dose to cause deterministic radiation effects, for example: A deviation of the patient's body diameter from the standard CTDI phantom size may lead to a patient's skin dose that is noticeably higher than indicated by the accumulated peripheral CTDI 100. Such a deviation may occur, for example, if a body perfusion examination is performed with a very thin patient. Repeating examinations within a short time period (compared to the biological recovery time for deterministic radiation effects) may lead to deterministic radiation damages, even if the accumulated peripheral CTDI 100 of the single examinations was below 1 Gy. By using the default Siemens scan protocols for patients with a standard patient size, without changing the default settings of the scan parameters, and without repeating the scans, the accumulated peripheral CTDI 100 will be kept reasonably below 1 Gy. The following list gives examples of situations that may lead to an accumulated peripheral CTDI 100 of 1.0 Gy and above (numbers are approximations). The list refers to default Siemens scan protocols and concentrates on scan modes with relatively high radiation exposure. This list is not exhaustive. Use of perfusion protocols with changes in kv, scan times, or mas, for example: Neuro PCT with tube voltage changed from 80 kv to 120 kv ( 1.2 Gy) Neuro PCT with mas increased from 200 mas to 580 mas Use of interventional protocols, for example: Head Intervention i-fluoro with an accumulated scan time of 21 s Head Intervention i-fluoro with 10 s scan time and mas increased from 100 mas to 220 mas Head Intervention i-fluoro with 15 s scan time and tube voltage increased from 120 kv to 140 kv Scanning of sequence protocols without table feed, for example: Approximately 16 scans of Head Neuro Seq without table feed Repeating standard sequences or spiral scans within an examination, for example: Repeated application of the default protocol Head Neuro Seq (approximately 16 times) Repeated application of the default protocol Abdomen Seq (approximately 93 times) Repeated application of the default protocol Abdomen Routine (approximately 89 times) 22 Dosimetry and imaging performance report System Owner Manual

23 Dosimetry and imaging performance report 1 To prevent unintended, excessive exposure, the CT system provides tools for Dose Notification and Dose Alert according NEMA XR-25 and IEC (Ed. 3.1). The default threshold value for Dose Alert is an accumulated CTDI vol of 1.0 Gy for adult patients and 1.0 Gy for pediatric patients. Ratio of peripheral CTDI 100 to displayed CTDI vol In general, the accumulated peripheral CTDI 100 for a scan can be derived from the displayed CTDI vol by multiplying the CTDI vol with a given factor that depends on the tube voltage and shaped filter used: Tube Voltage Shaped Filter: Narrow Standard CTDI phantom size: Ø 16 cm Ø 32 cm Ø 16 cm Ø 32 cm 70 kv kv KV kv kv kv kv kv Sn 100 kv Sn 140 kv Ratio of peripheral CTDI 100 to displayed CTDI vol Tolerances for CTDI According to: 21 CFR The actual exposure values, such as CTDI 100, CTDI w, CTDI vol and DLP, may deviate from the values displayed at the scanner and may deviate from the values stated in this manual within the following tolerances: Typical deviation* within ± 10% Max. tolerance* ± 20% *) Not including the dosemeter's tolerance; verified with dosemeter according IEC Tolerances for CTDI values Linearity of the radiation output (linearity of measured dose related to displayed mas): ± 10% Conversion factor for CTDI vol from Ø 32 cm phantom to Ø 16 cm phantom The displayed and reported CTDI vol and DLP refer to cylindrical PMMA phantoms with a diameter of 16 cm for head protocols and with a diameter of 32 cm for all body protocols (adult and pediatric protocols) according to IEC Neck protocols refer to the 32 cm phantom, too. The table below lists factors for the conversion of the CTDI vol and the DLP from the CTDI phantom size of Ø 32 cm to the CTDI phantom size of Ø 16 cm. SOMATOM Drive 23

24 1 Dosimetry and imaging performance report The table below provides conversion factors to calculate the CTDI vol and DLP for the 16 cm phantom from the values of a 32 cm phantom. The factors are stated separately for each setting of shaped filter. Please note that for adult neck protocols the standard shaped filter is used and for pediatric body and pediatric neck protocols the narrow shaped filter is used Conversion factor for CTDI vol Conversion factor from Ø 32 cm to Ø 16 cm Tube Voltage Shaped filter Standard Shaped filter Narrow 70 kv kv kv kv kv kv kv kv Sn 100 kv Sn 140 kv Conversion factor for CTDI volfrom Ø 32 cm to Ø 16 cm Example For a typical pediatric body protocol at 100 kv, the displayed CTDI vol (related to the Ø 32 cm CTDI-phantom) is 3.00 mgy cm; see ( Page 8 Typical CT conditions of operation). For the same protocol, the CTDI vol of a Ø 16 cm CTDIphantom is 2.5 times higher than the CTDI vol of a Ø 32 cm CTDI-phantom, resulting in 7.50 mgy CTDI vol for topograms The CTDI vol for topogram scans may be estimated according to IEC Since the collimation (6 0.6 mm) and table speed (100 mm/s) for the topogram is fixed, the CTDI vol for topograms is stated in the following table depending on the kv and ma values: Protocol type Head Adult body Child body Shaped filter Standard Standard Narrow Phantom size Ø 16 cm Ø 32 cm Ø 32 cm CTDI vol µgy/ma CTDI vol µgy/ma CTDI vol µgy/ma 70 kv kv kv kv Dosimetry and imaging performance report System Owner Manual

25 Dosimetry and imaging performance report 1 Protocol type Head Adult body Child body Shaped filter Standard Standard Narrow Phantom size Ø 16 cm Ø 32 cm Ø 32 cm CTDI vol µgy/ma CTDI vol µgy/ma CTDI vol µgy/ma 110 kv kv kv kv CTDI vol for topograms Geometric efficiency in the z-direction The dose efficiency is defined by IEC as the integral of the free in air dose profile in the isocenter along the z-axis over the acquisition range in the z-direction. It is expressed as percentage of the total integral of the dose profile in the z-direction. The acquisition range is the distance spanned by the selected detector elements along the z-axis. The displayed CTDI vol and DLP reflect the dose efficiency of a collimation according to the definition of CTDI vol. Correlation of dose profile and collimation with regards to dose efficiency y z Dose z-axis (1) Total dose profile width (2) Dose profile (3) Detector (4) Acquisition range Dose efficiency values for the various collimation types Acquisition Total collimation Dose efficiency 2 1 mm 2.0 mm 79% 1 5 mm 5.0 mm 84% mm 6.0 mm 70% SOMATOM Drive 25

26 1 Dosimetry and imaging performance report Acquisition Total collimation Dose efficiency mm 4.8 mm 50% mm 4.8 mm 50% 1 10 mm 10.0 mm 92% mm 12.0 mm 71% mm 14.4 mm 78% mm 19.2 mm 82% mm 19.2 mm 76% mm 38.4 mm 90% mm 38.4 mm 87% Dose efficiency values of CT scans For CT scans with a dose efficiency lower than 70%, a message containing information about the dose efficiency is displayed after a scan range is loaded. The user has to confirm the message before starting the scan Dose profiles According to: 21 CFR Dose profiles for single axial scans have been measured for the narrowest and widest collimations, as well as for a mid-range collimation. For each of these collimations, the dose profiles have been measured without any phantom (free air), at the center of the Ø 16 cm CTDI phantom (head) and at the center of the Ø 32 cm CTDI phantom (body). The phantoms were centered in the isocenter and aligned with the scanner axes. For the measurements, a semiconductor diode sensor was moved through the phantom. Dose profile diagrams In the diagrams below, dose profiles (thick lines) are presented as a percentage of their maximum value. Sensitivity profiles for the detector slices used in these collimations are plotted as thin lines (sum of single-slice sensitivity profiles). The dotted lines indicate the nominal collimation. Nominal values and tolerances for acceptance testing The stated tolerances are determined by the accuracy of the measurement method. For acceptance testing, dose profile widths are measured using film (GAFCHROMIC XR-QA / XR-QA2) and without any phantom. The tube is fixed and positioned at 12 o'clock. The exposure parameters are chosen to overexpose the film (120 kv, 160 ma, 10 s). Using this method, no densitometry is needed to evaluate the film. The width of the blackened range is a measure of the base width of the profile. Nominal values and tolerances are defined accordingly. 26 Dosimetry and imaging performance report System Owner Manual

27 Dosimetry and imaging performance report 1 Dose profile diagrams no phantom phantom 16 cm phantom 32 cm 2 1 mm mm mm x-axis: z-position [mm] y-axis: rel. dose & ssp[%] Dose profiles Full Width at Half Maximum (FWHM) of dose profiles Collimation No phantom Ø 16 cm phantom Ø 32 cm phantom Tolerance 2 1 mm 2.5 mm 2.7 mm 2.9 mm ± 1.5 mm mm 18 mm 22 mm 55 mm ± 4.0 mm mm 43 mm 45 mm 88 mm ± 4.0 mm Full Width at Half Maximum (FWHM) of dose profiles Nominal values and tolerances for acceptance testing Collimation Nominal blackening width Tolerance 2 1 mm 3.5 mm ± 1.0 mm mm 19.4 mm ± 1.5 mm mm 45.5 mm ± 2.0 mm Nominal values and tolerances for acceptance testing SOMATOM Drive 27

28 1 Dosimetry and imaging performance report Beam quality, leakage technique factors and minimum filtration According to: 21 CFR Tube voltage Half Value Layer (HVL) 70 kv 4.0 mm Al (typical mm*) 80 kv 4.5 mm Al (typical mm*) 90 kv 5.0 mm Al (typical mm*) 100 kv 5.0 mm Al (typical mm*) 110 kv 5.0 mm Al (typical mm*) 120 kv 5.0 mm Al (typical mm*) 130 kv 5.0 mm Al (typical mm*) 140 kv 5.0 mm Al (typical mm*) Sn 100 kv 5.0 mm Al (typical mm*) Sn 140 kv 5.0 mm Al (typical mm*) *) Depending on shaped filter Beam quality 0.88 mgy/h Leakage radiation of X-ray tube housing assembly at 1 m distance to focal spot with 145 kv, 4600 W Minimum filtration, permanent in the useful beam (tube housing assembly) Minimum filtration, permanent in the useful beam (beam limiting device) Additional filtration, conditional in the useful beam (beam limiting device) Leakage technique factors Quality equivalent filtration 6.8 mm Al at 145 kv 0.3 mm Ti + 1 mm C, (2.9 mm Al 140 kv/hvl 8.4 mm Al) 0.5 mm Al (0.5 mm Al 140 kv/hvl 9.4 mm Al) 0.4 mm Sn (47 mm Al 140 kv/hvl 9.4 mm Al) Minimum filtration CARE filter Tube A and tube B CARE filter Tube A and tube B Setting of shaped filter: standard (e.g. head and standard body protocols) CARE filter Tube A and tube B Setting of shaped filter: narrow (e.g. cardiac and pediatric body protocols) (protocols with setting Sn 100 kv or Sn 140 kv) Performance specification of automatic exposure controls The CT scanner offers different types of automatic exposure controls for adaptation of the exposure to the indvidual patient. CARE Dose 4D: mas adaptation to patient size, longitudinal, and angular tube current modulation ECG-Pulsing: Adaptation of tube current to the patient's ECG signal 28 Dosimetry and imaging performance report System Owner Manual

29 Dosimetry and imaging performance report 1 X-CARE: Control of the angular tube current to reduce dose for an angular segment with radiation sensitive organs, such as eye lenses and breast tissue CARE kv: Optimization of kv to minimize patient dose but maintaining image quality The modulation type applied depends on the protocol selected and the individual setting: Protocol types, organ characteristics Abdomen AngioBody Pediatric Head Pediatric Angio Head Neck Pelvis Runoff Shoulder Spine Thorax Adult Head Adult Angio Head Respiratory Body-Perfusion Extremities Osteo Cardio (Z exposure control for chest pain protocols only) X-CARE protocols Modulation type XYZ exposure control (CARE Dose 4D) Z exposure control (CARE Dose 4D) XY exposure control (CARE Dose) Fixed exposure control (CARE Dose 4D) ECG-Pulsing (possibly combined with fixed exposure control or Z exposure control) Angular modulated exposure control (X-CARE) (possibly combined with fixed exposure control, Z exposure control or XY exposure control) The tube current is adapted to the patient size. It is varied along the z-axis according to the patient s attenuation profile and modulated angularily according to the patient's angular attenuation profile that has been measured online. The tube current is adapted to the patient size and varied along the z-axis according to the patient s attenuation profile. The tube current is modulated angularily according to the patient's angular attenuation profile that has been measured online and is based on the user-selected mas. The tube current is adapted to an average patient size and kept constant. The tube current is pulsed according to the patient's ECG signal. The tube current is modulated angularly relatively to the patient's orientation to reduce dose in certain body ranges (eye lenses, breast tissue). Modulation types of automatic exposure control, related to the selected protocols CARE Dose 4D CARE Dose 4D automatically adapts the tube current to the patient's body size and shape. Using the patient's topogram, Care Dose 4D evaluates two profiles of the patient's body size in the a.p. and lateral directions, related to the X-ray attenuation of the patient's body. Based on these profiles, the mas value is adapted to the patient during the subsequent CT scans. The adaptation follows a curve, which determines the correlation between patient size and tube current. The adaptation curve has been derived from clinical optimization for constant diagnostic image quality. SOMATOM Drive 29