Siemens 2005C User Manual
SOMATOM
Spirit
Application Guide
Protocols
Principles
Helpful Hints
syngo 3D
syngo Fly Through
syngo Dental CT
syngo Osteo CT
syngo Volume Evaluation
syngo Dynamic Evaluation
Software Version syngo CT 2005C
The information presented in this Application Guide is
for illustration only and is not intended to be relied
upon by the reader for instruction as to the practice of
medicine. Any health care practitioner reading this
information is reminded that they must use their own
learning, training and expertise in dealing with their
individual patients.
This material does not substitute for that duty and is
not intended by Siemens Medical Solutions Inc., to be
used for any purpose in that regard. The drugs and
doses mentioned are consistent with the approval
labeling for uses and/or indications of the drug. The
treating physician bears the sole responsibility for the
diagnosis and treatment of patients, including drugs
and doses prescribed in connection with such use.
The Operating Instructions must always be strictly
followed when operating the CT System. The source
for the technical data is the corresponding data sheets.
The pertaining operating instructions must always be
strictly followed when operating the SOMATOM Spirit.
The statutory source for the technical data are the
corresponding data sheets.
We express our sincere gratitude to the many
customers who contributed valuable input.
Special thanks to Heike Theessen, Christiane
Bredenhöller, Kristin Pacheco, Karin Ladenburger, and
Chen Mahao for their valuable assistance.
To improve future versions of this Application Guide,
we would greatly appreciate your questions,
suggestions and comments.
Please contact us:
USC-Hotline:
Tel. no.+49-1803-112244
email ct-application.hotline@med.siemens.de
Editor: Ute Feuerlein
2
Overview
User Documentation 14
Scan and Reconstruction 16
Dose Information 28
Workflow Information 36
Application Information 54
Head 70
Neck 88
Shoulder 94
Thorax 98
Abdomen 110
Pelvis 124
Spine 132
Upper Extremities 146
3
Lower Extremities 154
Vascular 162
Specials 176
Children 184
syngo 3D 240
syngo Fly Through 258
syngo Dental CT 268
syngo Osteo CT 274
syngo Volume Evaluation 288
syngo Dynamic Evaluation 306
4
5
Contents
User Documentation 14
Scan and Reconstruction 16
• Concept of Scan Protocols 16
• Scan Set Up 17
• Scan Modes 18
- Sequential Scanning 18
- Spiral Scanning 18
- Dynamic Serioscan 18
• Slice Collimation and Slice Width 19
- Slice Collimation and Slice Width for
Spiral Mode and HR Spiral Mode 20
- Slice Collimation and Slice Width for
Sequence Mode and HR Sequence Mode 20
• Increment 21
• Pitch 22
• Window values 23
• Kernels 24
• Image Filters 25
• Improved Head Imaging 27
Dose Information 28
• CTDI
and CTDI
W
• Effective mAs 30
• CARE Dose 32
Vol
- How does CARE Dose work? 32
Workflow Information 36
• Recon Jobs 36
• Examination Job Status 37
• Auto Load in 3D and Post-processing
Presets 38
• How to Create your own
Scan Protocols 39
- Edit/Save Scan Protocol 39
- Scan Protocol Manager 40
6
28
Contents
• Contrast Medium 45
- The Basics 45
-IV Injection 47
-Bolus Tracking 48
- Test Bolus using CARE Bolus 50
- Test Bolus 51
Application Information 54
• SOMATOM life 54
-General Information 54
-Key Features 55
- Description 56
- Access to Computer Based Training or
Manuals on CD ROM 57
- SRS Based Services 58
- Download of Files 59
- Contact incl. DICOM Images 60
- Trial Order and Installation 62
• Image Converter 64
• File Browser 66
• Patient Protocol 68
Head 70
• Overview 70
• Hints in General 71
- Head Kernels 71
• HeadRoutine 72
• HeadSeq 74
• InnerEarHR 76
• InnerEarHRSeq 78
• Sinus 80
• SinusSeq 82
• Orbita 84
• Dental 86
7
Contents
Neck 88
• Overview 88
• Hints in General 89
-Body Kernels 90
• Neck 92
Shoulder 94
• Overview 94
• Hints in General 95
-Body Kernels 95
• Shoulder 96
Thorax 98
• Overview 98
• Hints in General 99
- Body Kernels 101
• ThoraxRoutine/ThoraxRoutine08s 102
• ThoraxFast 104
• ThoraxHRSeq 106
• LungLowDose 108
Abdomen 110
• Overview 110
• Hints in General 111
- Body Kernels 113
• AbdomenRoutine/AbdomenRoutine08s 114
• AbdomenFast 116
• AbdMultiPhase/AbdMultiPhase08s 118
• AbdomenSeq 122
8
Contents
Pelvis 124
• Overview 124
• Hints in General 125
- Body Kernels 125
• Pelvis 126
• Hip 128
• SI_Joints 130
Spine 132
• Overview 132
• Hints in General 133
- Body Kernels 135
• C-Spine 136
• C-SpineSeq 138
• Spine 140
• SpineSeq 142
• Osteo 144
Upper Extremities 146
• Overview 146
• Hints in General 147
- Body Kernels 148
• WristHR 150
• ExtrRoutineHR 152
Lower Extremities 154
• Overview 154
• Hints in General 155
- Body Kernels 156
• KneeHR 158
• FootHR 160
• ExtrRoutineHR 161
9
Contents
Vascular 162
• Overview 162
• Hints in General 163
- Head Kernels 163
- Body Kernels 163
• HeadAngio/HeadAngio08s 164
• CarotidAngio/CarotidAngio08s 166
• ThorAngio/ThorAngio08s 168
• Embolism 170
• BodyAngioRoutine/BodyAngioRoutine08s 172
• BodyAngioFast 174
Specials 176
• Overview 176
- Trauma 176
- Interventional CT 176
- Test Bolus 176
• Trauma 177
- The Basics 177
• PolyTrauma 178
• HeadTrauma 180
• Interventional CT 181
• Biopsy 182
• TestBolus 183
Children 184
• Overview 184
• Hints in General 187
- Head Kernels 190
- Body Kernels 191
• HeadRoutine_Baby 192
• HeadRoutine_Child 194
• HeadSeq_Baby 196
• HeadSeq_Child 198
• InnerEar 200
• SinusOrbi 202
• Neck 204
10
Contents
• ThoraxRoutine_Baby 206
• ThoraxRoutine_Child 208
• ThoraxHRSeq_Baby 210
• ThoraxHRSeq_Child 212
• Abdomen_Baby 214
• Abdomen_Child 216
• Spine_Baby 218
• Spine_Child 220
• ExtrHR_Baby 222
• ExtrHR_Child 224
• HeadAngio 226
• HeadAngio08s 228
• CarotidAngio 230
• CarotidAngio08s 232
• BodyAngio 234
• BodyAngio08s 236
• NeonateBody 238
syngo 3D 240
- Multi Planar Reconstruction (MPR) 240
- Maximum Intensity Projection (MIP) 240
- Shaded Surface Display (SSD) 241
- Volume Rendering Technique (VRT) 241
- Prerequisites 242
• Workflow 242
- Loading the Images 242
- Creating Series 244
- Editing 246
- Documentation of Results 249
• Workflow for a CT Extremity Examination 250
- Using MPR/MPR Thick 250
- Using SSD 251
- Using VRT 251
• Workflow for a CT Angiography 252
- Using MIP/MIP Thin 252
- Using VRT/VRT Thin/Clip 253
• Hints in General 254
- Setting Views in the Volume Data Set 254
- Changing /Creating VRT Presets 255
11
Contents
- Auto Load in 3D and Post-processing
Presets 257
- Blow-up Mode 257
syngo Fly Through 258
• Key Features 258
• Prerequisites 259
• The Basics for CT Virtual Endoscopy 259
- SSD and VRT Presets for Endoscopic
Renderings 259
- Endoscopic Viewing Parameters/
Fly Cone Settings 260
- Patient Preparation 262
• Workflow 263
- Navigation of the Endoscopic Volume 265
- Fly Path Planning 266
syngo Dental CT 268
• The Basics 268
• Scan Protocols 269
• Additional Important Information 271
syngo Osteo CT 274
• The Basics 274
• Scanning Procedure 275
• Configuration 278
• Evaluation Workflow 282
• Additional Important Information 287
syngo Volume Evaluation 288
• Prerequisites 290
• Workflow 291
• General Hints 300
• Configuration 303
12
Contents
syngo Dynamic Evaluation 306
• Prerequisites 308
• Workflow 309
- 1. Loading the Images 309
- 2. Inspecting the Input Images 310
- 3. Generation of Parameter Images 310
- 4. Creating a Baseline Image 313
- 5. Evaluation of Region of Interests 314
- 6. Enhancement Curve 315
- 7. Documentation of Results 316
• General Hints 317
13
User Documentation
For further information about the basic operation,
please refer to the corresponding syngo CT Operator
Manual:
syngo CT Operator Manual
Volume 1:
Security Package
Basics
Preparations
Examination
CARE Bolus CT
syngo CT Operator Manual
Volume 2:
syngo Patient Browser
syngo Viewing
syngo Filming
syngo 3D
syngo CT Operator Manual
Volume 3:
syngo Data Set Conversion
syngo Dental CT
syngo Dynamic Evaluation
syngo Osteo CT
syngo Volume
14
User Documentation
15
Scan and Reconstruction
Concept of Scan Protocols
The scan protocols for adult and children are defined
according to body regions – Head, Neck, Shoulder,
Thorax, Abdomen, Pelvis, Spine, Upper Extremities,
Lower Extremities, Specials, and Vascular.
The general concept is as follows: All protocols without
suffix are standard spiral modes. E.g., “Shoulder”
means the spiral mode for the shoulder.
The suffixes of the protocol name are follows:
“Routine“: for routine studies
“Seq”: for sequence studies
“Fast“: use a higher pitch for fast acquisition
“HR“: use a thinner slice width (1.0 mm) for High Resolution studies and a thicker slice width for soft tissue
studies
The availability of scan protocols depends on the system configuration.
16
Scan and Reconstruction
Scan Set Up
Scans can be simply set up by selecting a predefined
examination protocol. To repeat any mode, just click
the chronicle with the right mouse button for “repeat”.
To delete it, select “cut“. Each range name in the chron
icle can be easily changed before “load“.
Multiple ranges can be run either automatically with
“auto range“, which is denoted by a bracket connecting
the two ranges, or separately with a “pause” in
between.
-
17
Scan and Reconstruction
Scan Modes
Sequential Scanning
This is an incremental, slice-by-slice imaging mode in
which there is no table movement during data acquisi
tion. A minimum interscan delay in between each
acquisition is required to move the table to the next
slice position.
Spiral Scanning
Spiral scanning is a continuous volume imaging mode.
The data acquisition and table movements are performed simultaneously for the entire scan duration.
There is no interscan delay and a typical range can be
acquired in a single breath hold.
Each acquisition provides a complete volume data set,
from which images with overlapping can be reconstructed at any arbitrary slice position. Unlike the
sequence mode, spiral scanning does not require additional radiation to obtain overlapping slices.
-
Dynamic Serioscan
Dynamic serial scanning mode without table feed.
Dynamic serio can still be used for dynamic evaluation,
such as Test Bolus.
18
Scan and Reconstruction
Slice Collimation and Slice Width
Slice collimation is the slice thickness resulting from
the effect of the tube-side collimator and the adaptive
detector array design. In Multislice CT, the Z-coverage
per rotation is given by the product of the number of
active detector slices and the collimation (e.g., 2 x
mm).
1.0
Slice width is the FWHM (full width at half maximum)
of the reconstructed image.
With the SOMATOM Spirit, you select the slice collimation together with the slice width desired. The slice
width is independent of pitch, i.e. what you select is
always what you get. Actually, you do not need to be
concerned about the algorithm any more; the software
does it for you.
The Recon icon on the chronicle will be labeled with
“RT”. After the scan, the Real Time displayed image
series has to be reconstructed.
The following tables show the possibilities of image
reconstruction in spiral and sequential scanning.
19
Scan and Reconstruction
Slice Collimation and Slice Width for Spiral Mode and HR Spiral Mode
1 mm: 1, 1.25, 2, 3, 5 mm
1.5 mm: 2, 3, 5, 6 mm
2.5 mm: 3, 5, 6, 8, 10 mm
4 mm: 5, 6, 8, 10 mm
5 mm: 6, 8, 10 mm
Slice Collimation and Slice Width for Sequence Mode and HR Sequence Mode
1.0 mm: 1, 2 mm
1.5 mm: 1.5, 3 mm
2.5 mm: 2.5, 5 mm
4.0 mm: 4, 8 mm
5.0 mm 5, 10 mm
20
Scan and Reconstruction
Increment
The increment is the distance between the reconstructed images in the Z direction. When the increment
chosen is smaller than the slice thickness, the images
are created with an overlap. This technique is useful to
reduce partial volume effect, giving you better detail of
the anatomy and high quality 2D and 3D post-process
ing.
Slice Thickness = 10 mm
-
Increment = 10 mm
Reconstruction Increment
Increment = 5 mm
Increment = 3 mm
21
Scan and Reconstruction
Pitch
In single slice CT:
Pitch = table movement per rotation/slice collimation
E.g.,: slice collimation = 5 mm,
table moves 5 mm per rotation, then pitch = 1.
With the Siemens Multislice CT, we differentiate
between:
Feed/Rotation, the table movement per rotation
Volume Pitch, table movement per rotation/single
slice collimation.
Pitch Factor, table movement per rotation/complete
slice collimation.
E.g., slice collimation = 2 x 5 mm,
table moves 10 mm per rotation,
then Volume Pitch = 2, Pitch Factor = 1.
With the SOMATOM Spirit, the pitch, slice, collimation,
rotation time, and scan range can be adjusted. The
pitch factor can be selected from 0.5-2.
Pitch 1
Pitch Models
22
Pitch 1.5
Pitch 2
Scan and Reconstruction
Window values
The Scale of the CT Hounsfield Units is from -1024 to
+3071.
The displayed window values have to correspond to
the anatomical structure.
Windowing is used to optimize contrast and brightness
of images.
Hounsfield Units
Spleen
Fat
Window
center C
Kidneys
Pancreas
Lung
Adrenal
Glands
Blood
Heart
Window
width W
Bones
Water
Breast
Air
Organ specific window values
Gray scale
white
CT-window values
Liver
Tumo r
Bladder
Colon
black
23
Scan and Reconstruction
Kernels
There are 3 different types of kernels: “H“ stands for
Head, “B“ stands for Body, “C“ stands for ChildHead.
The image sharpness is defined by the numbers – the
higher the number, the sharper the image; the lower
the number, the smoother the image.
A set of 18 kernels is supplied, consisting of:
• 6 body kernels: smooth (B20s), medium smooth
(B31s), medium (B41s), medium sharp (B50s), sharp
(B60s), high res (B70s)
• 7 head kernels: smooth (H21s), medium smooth
(H31s), medium (H41s), medium sharp (H50s),
sharp (H60s), high res (H70s), ultra high res (H80s)
• 3 child head kernels: smooth (C20s), medium
(C30s), sharp (C60s)
• 2 special kernels: S80s, U90s
Note: Do not use different kernels for body parts other
than what they are designed for.
For further information regarding the kernels, please
refer to the “Hints in General” of the corresponding
body region.
24
Scan and Reconstruction
Image Filters
There are 3 different filters available:
LCE: The Low-contrast enhancement (LCE) filter
enhances low-contrast detectability. It reduces the
image noise.
• Similar to reconstruction with a smoother kernel
• Reduces noise
• Enhances low-contrast detectability
• Adjustable in four steps
• Automatic post-processing
25
Scan and Reconstruction
HCE: The High-contrast enhancement (HCE) filter
enhances high-contrast detectability. It increases the
image sharpness, similar to reconstruction with a
sharper kernel.
• Increases sharpness
• Faster than raw-data reconstruction
• Enhances high-contrast detectability
• Automatic post-processing
ASA: The Advanced Smoothing Algorithm (ASA) filter reduces noise in soft tissue, while edges with high
contrast are preserved.
• Reduces noise without blurring of edges
• Enhances low-contrast detectability
• Individually adaptable
• Automatic post-processing
26
Scan and Reconstruction
Improved Head Imaging
An automatic bone correction algorithm has been
included in the standard image reconstruction. Using a
new iterative technique, typical artifacts arising from
the beam-hardening effect, e.g., Hounsfield bar, are
minimized without any additional post-processing.
This advanced algorithm allows for excellent images of
the posterior fossa, but also improves head image
quality in general. Bone correction is activated auto
matically for body region “Head”.
In order to optimize image quality versus radiation
dose, scans in the body region “Head” are provided
within a maximum scan field of 300 mm with respect
to the iso-center. No recon job with a field of view
exceeding those limits will be possible. Therefore,
patient positioning has to be performed accurately to
ensure a centered location of the skull.
Head image without
correction.
-
Head image with corrections.
27
Dose Information
CTDIW and CTDI
Vol
The average dose in the scan plane is best described by
the CTDIW for the selected scan parameters. The CTDI
is measured in the dedicated plastic phantoms – 16 cm
diameter for head and 32 cm diameter for body (as
defined in IEC 60601 –2 – 44). This dose number gives
a good estimate for the average dose applied in the
scanned volume as long as the patient size is similar to
the size of the respective dose phantoms.
Since the body size can be smaller or larger than
32 cm, the CTDIW value displayed can deviate from the
dose in the scanned volume.
The CTDIW definition and measurement is based on single axial scan modes. For clinical scanning, i.e. scanning of entire volumes in patients, the average dose
will also depend on the table feed in between axial
scans or the feed per rotation in spiral scanning. The
dose, expressed as the CTDI
, must therefore be cor-
W
rected by the Pitch Factor of the spiral scan or an axial
scan series to describe the average dose in the scanned
volume.
For this purpose the IEC defined the term “CTDIVol“ in
September 2002:
W
CTDI
= CTDIW/Pitch Factor
Vol
This dose number is displayed on the user interface for
the selected scan parameters.
28
Dose Information
The CTDI
tion of the radiation risk associated with CT examination. For the purpose, the concept of the “Effective
Dose“ was introduced by ICRP (International Commis
sion on Radiation Protection). The effective dose is
expressed as a weighted sum of the dose applied not
only to the organs in the scanned range, but also to the
rest of the body. It could be measured in whole body
phantoms (Alderson phantom) or simulated with
Monte Carlo techniques.
The calculation of the effective dose is rather complicated and has to be done by sophisticated programs.
These have to take into account the scan parameters,
the system design of individual scanner, such as x-ray
filtration and gantry geometry, the scan range, the
organs involved in the scanned range and the organs
affected by scattered radiation. For each organ, the
respective dose delivered during the CT scanning has
to be calculated and then multiplied by its radiation
risk factor. Finally, the weighted organ dose numbers
are added up to get the effective dose.
The concept of effective dose allows the comparison of
radiation risk associated with different CT or x-ray
exams, i.e. different exams associated with the same
effective dose would have the same radiation risk for
the patient. It also allows comparing the applied x-ray
exposure to the natural background radiation,
e.g., 2 – 3 mSv per year in Germany.
value does not provide the entire informa-
vol
-
29
Dose Information
Effective mAs
In sequential scanning, the dose (Dseq) applied to the
patient is the product of the tube current-time (mAs)
and the CTDI
D
= D
seq
In spiral scanning, however, the applied dose (Dspiral)
is influenced by the “classical“ mAs (mA x Rot Time)
and in addition by the Pitch Factor. For example, if a
Multislice CT scanner is used, the actual dose applied
to the patient in spiral scanning will be decreased
when the Pitch Factor is larger than 1, and increased
when the Pitch Factor is smaller than 1. Therefore, the
dose in spiral scanning has to be corrected by the Pitch
Factor:
D
= (D
spiral
To make it easier for the users, the concept of the
“effective“ mAs was introduced with the SOMATOM
Multislice scanners.
The effective mAs takes into account the influence of
pitch on both the image quality and dose:
Effective mAs = mAs/Pitch Factor
per mAs:
w
x mAs
CTDIw
x mA x Rot Time)/Pitch Factor
CTDIw
To calculate the dose you simply have to multiply the
CTDIw per mAs with the effective mAs of the scan:
D
spiral
= D
x effective mAs
CTDIw
30
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