The Reference in Single Source CT SOMATOM Definition Edge
Answers for life.
SOMATOM Definition Edge
Siemens CT Vision
Today’s reality Better healthcare for all patients is a key priority for the entire medical industry. But the realities of clinical practice often make this simple-to-understand goal quite difficult to realize: staying within budgets, reducing hospital stays, speeding up time to diagnosis, and dealing with personnel issues, while maintaining high clinical standards and throughput. At the same time, patients demand better and faster results.
Our approach In order to meet our share of responsibility in addressing these challenges, Siemens, from the earliest stages of research, product development, and design, relies upon the advice and recommendations of external medical experts to determine our focus – and this focus has been on the needs and demands of our end users. Over the years, this focus has been fine-tuned in four key areas: • to lead technological and medical advancement
• to maximize workflow efficiency • to make state-of-the-art CT affordable • to set the standard in customer care Our vision As a partner to our customers, we create CT innovations that lift clinical practice to the next level of excellence and enable wide access to better patient care. We believe that even the farthest technical horizons are temporary and can be surpassed with consistent dedication to improved healthcare. This visionary approach, backed
up by the, by far, largest R&D budgets in the healthcare industry, has made Siemens the undisputed innovation leader in CT over the last 35 years. And our ambitious global team continues to set the trend in an always changing environment, providing Answers for Life. Our solution In 2008, Siemens introduced the gold standard in CT technology, still unrivaled today: the SOMATOM® Definition Flash. And now, again, Siemens sets the
standard for Single Source CT: the SOMATOM Definition Edge with the revolutionary Stellar Detector with TrueSignal Technology. Developed with the clear goal of providing the latest in CT technology, the SOMATOM Definition Edge integrates the unique innovations of the SOMATOM Definition Flash into a groundbreaking Single Source CT system. Finally, Single Source CT imaging can unleash its full potential: offering uncompromised diagnostic outcome with highest image quality, acquired at impressively low
patient radiation. With the SOMATOM Definition Edge, Siemens again pushes the boundaries of patient care.
SOMATOM Definition Edge The Reference in Single Source CT
See the Unseen
Unprecedented spatial resolution Uncompromised temporal resolution Clinical field: Cardiovascular Unparalleled acquisition speed Clinical field: Acute care
12 14 16 18 20
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Dose reduction in low-signal imaging Dose reduction with SAFIRE Dose reduction with CARE kV Combined Applications to Reduce Exposure (CARE)
26 28 30 32
Specify the Unspecific
Calculi characterization in clinical routine Gout identification in clinical routine Reducing metal artifacts in clinical routine Improved dynamic imaging in clinical routine
38 40 42 44
Benefits and Technical Specifications
International Version. Not for distribution in the US.
Scan to see the unseen of Edge Technology features. www.siemens.com/somatom-definition-edge
SOMATOM Definition Edge The Reference in Single Source CT
See the unseen Get more from less Specify the unspecific
For decades, Siemens has been the undisputed innovation leader in high-end CT imaging. But the clinical need for higher image quality persists. Therefore, we proudly introduce the SOMATOM Definition Edge with the revolutionary Stellar Detector, the first fully-integrated detector. Designed to minimize electronic noise, it takes CT imaging where it has never gone before.
The uniqueness of the Stellar Detector allows the SOMATOM Definition Edge to generate ultra-thin slices, thus delivering the highest spatial resolution in CT. You can visualize even the finest image details, for example, for the most accurate stenosis and stent analysis. It lets you see what was previously unseen. The minimized noise level of the Stellar Detector together with SAFIRE – our raw-data-based iterative reconstruction – is perfect for ultra low-dose imaging, eliminating the contradiction of outstanding image quality with minimal dose. You get more diagnostic quality with less patient radiation. Additionally, Dual Energy (DE) is a reality for Single Source CT imaging. With the novel capabilities of the Stellar Detector and the only dose-optimized Single Source DE scan mode, the SOMATOM Definition Edge enables you to add tissue characteristics to the morphology. You can now specify formerly unspecific information for higher diagnostic outcome. With these unrivaled features, the SOMATOM Definition Edge enters new frontiers in medical imaging, becoming: The Reference in Single Source CT.
See the Unseen
See the Unseen Introducing the latest generation of CT detector technology: Siemens’ unique Stellar Detector, together with innovative Edge Technology, delivers slices thinner than the detector spacing.
focal spot Edge Technology Minimized cross-talk from the Stellar Detector creates an almost perfect model of the focal spot. The result is a slice thickness of 0.5 mm. Conventional Technology Cross-talk resulting from slice blurring in conventional detector.
A general principle in CT is that thinner slices deliver more image detail, but also less light quants per voxel, i.e., higher image noise. This lowers the signal-to-noise ratio (SNR) and leads to slice blurring. Conventional CT compensates by increasing dose. Clinical experience following the ALARA (As Low As Reasonably Achievable) principle has shown that a 0.6 mm collimator width is the optimum combination of slice thickness and dose. So further reduction of slice thickness was limited. Until now.
The Stellar Detector The Stellar Detector introduces the next generation in detector technology, succeeding gas and solid-state technology. Using nanotechnology, it is possible to miniaturize the electronic components on the detector elements, enabling their integration directly at the photodiode. So, for the first time, the electronics of the detector elements are fully integrated in the photodiode. This full electronic integration is Siemens' revolutionary TrueSignal Technology.
Edge Technology Electronic noise and cross-talk are minimized thanks to full electronic integration. Without cross-talk, intrinsic slice blurring between neighboring detector rows can be avoided and individual slice profiles are much more precise. Siemens’ Edge Technology creates an almost perfect model of the focal spot and detector, generating a slice thickness of 0.5 mm. Thanks to minimized electronic noise, the 0.5 mm slice has a sufficient signal contribution to be used in clinical routine.
Scan to learn more about the new Stellar Detector.
Unprecedented spatial resolution Innovation delivers outstanding results High spatial resolution in combination with a high signal-to-noise ratio (SNR) is a reliable indicator for excellent image quality. Together they describe the image detail level and sharpness that can be made visible while acquiring diagnostic CT images. In addition, a homogenic slice profile with the same spatial resolution and SNR everywhere in the entire Field of View (FOV) is essential for consistent high image quality. Other approaches in the market had to make compromises, for example by reducing the FOV size.
Increased image detail In addition to the Stellar Detector, the SOMATOM Definition Edge is equipped with Siemens’ renowned STRATON® tube with z-Sharp™ Technology. This combination is the essence of increasing spatial resolution. Using a flying focal spot with two distinct X-ray beams, z-Sharp acquires two individual, overlapping slices. With Edge Technology, the Stellar Detector now delivers slices with a thickness of 0.5 mm, resulting in a spatial resolution of up to 0.30 mm, which is equivalent to approximately 19 lp/cm.
Higher signal-to-noise ratio But how can the reduced light quants of a 0.5 mm slice be compensated for? The secret is the TrueSignal Technology of the Stellar Detector. Instead of increasing dose, it makes more efficient use of the initially available quants per voxel: As the electronic noise of the detector is virtually eliminated, the overall noise is reduced so that the quants contribute to a higher SNR. Consequently, thin slices of 0.5 mm can be used in clinical practice.
More consistent image quality By acquiring two distinct slices, z-Sharp collects twice the amount of projections. This avoids miscalculation of data points, as they are measured and not interpolated, providing a higher data quality. And as the slices are acquired in parallel, the data points are equidistant, resulting in a more consistent slice thickness compared to conjugate approaches. Adding the reduced slice blurring of the Stellar Detector, the slice profile overall becomes more homogeneous with consistent spatial resolution over the entire FoV.
Uncompromised temporal resolution Uncompromised rotation speed The core technology to achieve high rotation speed is the renowned STRATON tube. Based on direct anode cooling, it eliminates the need for heat storage and has an unmatched compact design. Together with new gantry architecture, this enables an additional increase in the rotation speed of the SOMATOM Definition Edge. Increased rotation speed means shorter rotation times. That means that the available signal per rotation is also reduced, which results in lower SNR or higher image
noise. Until now, this typically had to be compensated for by increasing the applied current which consequently required a higher generator power. But the Stellar Detector with TrueSignal Technology reduces electronic noise in the detector. This optimizes the initial SNR and thus avoids the need to further increase generator power.
Uncompromised performance The unique combination of Stellar Detector, STRATON tube and new gantry is the key benefit of the SOMATOM Definition Edge. With a rotation speed of 0.28 sec, it delivers a temporal resolution of 142.5 msec. At the same time, it utilizes the unique spatial resolution of up to 0.30 mm provided by the Stellar Detector. And its gantry concept now makes it possible to use it within the entire FoV of up to 500 mm. Only with this uncompromised performance can you achieve outstanding clinical results.
Uncompromised image detail High temporal resolution is essential for motion-artifact-free imaging, e.g., in cardiac examinations to perform accurate stenosis measurements. But this benefit is contradicted when compromises like reduced image detail or limited FoV have to be made in order to utilize high rotation speeds. Therefore, the SOMATOM Definition Edge was specifically designed to go beyond these limitations. Its revolutionary Stellar Detector provides unprecedented image detail independent of rotation speed.
Clinical field: Cardiovascular
Cardiac imaging combines two crucial requirements in CT imaging: high spatial resolution at high temporal resolution. One example that demonstrates the benefits of the new SOMATOM Definition Edge regarding artifact-free high resolution is stent imaging in cardiology.
High spatial resolution In cardiology, high spatial resolution only makes sense when it can be provided in concert with high temporal resolution. With only limited spatial resolution, the visualization of small occlusions might be impaired, resulting in blurring artifacts. These may affect the diagnosis, as it can conceal the actual stenosis. With higher spatial resolution, blurring artifacts are reduced, allowing better assessment of the lumen.
High temporal resolution Spatial resolution is of no benefit without high temporal resolution. Limited spatial resolution can lead to motion artifacts from the respective vessel. This increases the danger of false positive findings, meaning a stenosis is diagnosed, although the finding is a result of the misinterpreted fuzzy visualization of the vessel. Therefore, high spatial resolution must be delivered together with high temporal resolution; not one or the other.
In-stent restenosis A common clinical question typically posed in stent follow-up examinations is whether the vessel has re-occluded after the stent has been set. As stents are very small objects within constantly moving vessels, this procedure requires precise image details without motion artifacts. With the unique combination of highest spatial resolution at uncompromised temporal resolution, the SOMATOM Definition Edge offers the most advanced solution for this clinical challenge.
collimation: 128 x 0.5 mm spatial resolution: 0.30 mm temp resolution: 142 msec scan time: 5 sec scan length: 119 mm rotation time: 0.28 sec CTDIvol: 38 mGy DLP: 656 mGy cm eff. dose: 9.2 mSv
High resolution imaging of stents at uncompromised temporal resolutions allows for sound exclusion of in-stent stenosis.
230 mm / sec
Unparalleled acquisition speed
In conventional CT systems, high resolution means scanning at reduced pitch. With z-Sharp, high resolution is independent of pitch, making high resolution available for high-pitch acute care examinations.
Uncompromised spatial resolution One of the most challenging demands in CT is providing high acquisition speed without compromising spatial resolution; for example, in acute-care scenarios when unconscious or uncooperative patients have to be scanned quickly. Here the ‘golden hour’ to diagnosis mandates precise localization and identification of critical injuries. The goal is to prevent motion artifacts when patients have only a limited ability to hold their breath.
In such cases the SOMATOM Definition Edge is in a class of its own. The new level of image detail with a spatial resolution of up to 0.30 mm provided by the Stellar Detector allows visualizations of even the finest fractures or lesions. Additionally, the newly designed gantry, together with Siemens’ most advanced patient table, now allows an acquisition speed of up to 230 mm/sec. This takes motion out of the equation, increasing the diagnostic reliability in such crucial cases.
Conventional technology R2
z-Sharp technology R1
pitch = 1.4
pitch = 1.0
High-pitch high-resolution CT Increasing spatial resolution beyond the detector width requires overlapping slices. For conventional CT systems, this means reducing pitch to facilitate the slice overlap. For scans requiring high pitch, the reduced or missing overlap then reduces spatial resolution. But with z-Sharp, the overlap results from an acquisition with two distinct projections coming from the STRATON tube. Consequently, the two slices overlap independently of the pitch used and can always provide highest resolution.
pitch = 0.55
pitch = 1.4
pitch = 1.0
pitch = 0.55
The uniqueness of the SOMATOM Definition Edge is the combination of the Stellar Detector, the STRATON tube with z-Sharp, the new gantry with 0.28 sec rotation speed, and the patient table that supports a pitch of 1.7. This allows a scan speed of up to 230 mm/sec. Clinically, this means scanning the whole heart in half a second, a 50 cm thorax in roughly two seconds or performing a two-meter scan of the entire body in nearly eight-and-a-half seconds, all at a spatial resolution of up to 0.30 mm.
Clinical field: acute care
Acute care is one of the most challenging applications in CT. This clinical field shows how the new SOMATOM Definition Edge is the answer when examining an acute-care patient with severe injuries of the upper spine.
The golden hour Acute care demands the highest spatial resolution at the fastest possible acquisition speed, which is very challenging. The reason is that the ‘golden hour’ is crucial: Appropriate therapy which is instituted within this time frame is likely to have a much more significant impact on improving patient outcome by decreasing morbidity and mortality. Consequently, the guiding imaging for these decisions must deliver the required answers quickly. Therefore, CT is the modality of choice.
High-resolution high-speed imaging In addition to the fact that every second counts in the golden hour, there is another reason to use the fastest possible acquisition speed. Acute-care patients are often uncooperative, so it is essential that the CT scan is performed as fast as possible to reduce movement artifacts. But you want to be sure you are not reducing spatial resolution. When looking at fractures, for example, it is essential to assess whether larger fractures or broken bones have ruptured small vessels and caused internal bleeding, or
whether very small fractures of the spine have impacted the spinal cord. So it is imperative to acquire the highest possible spatial resolution at the fastest possible acquisition speed. The SOMATOM Definition Edge with the unique STRATON tube makes spatial resolution independent of the selected pitch. And having the patient table from the SOMATOM Definition Flash at a pitch of 1.7 is possible. This allows an acquisition speed of up to 230 mm/sec at a spatial resolution of 0.30 mm.
collimation: 128 x 0.5 mm spatial resolution: 0.30 mm scan time: 7.6 sec scan length: 230 mm rotation time: 1.0 sec CTDIvol: 22.4 mGy DLP: 590 mGy cm eff. dose: 8.9 mSv
Spine image of a 70-year-old patient with vertebrae degeneration visualizing even the finest bone structures.
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Get More from Less The unique Stellar Detector with TrueSignal Technology reflects the continuation of Siemens’ commitment to deliver best image quality at lowest signal or lowest dose.
The low signal capability of a detector can be described best by a high SNR. The Stellar Detector with TrueSignal Technology minimizes electronic noise – optimal for low signal and dose imaging.
There are various reasons to scan with low signals. For example, bariatric patients can cause strong attenuation. But low signals can be fully intentional, mainly driven by the desire to reduce dose. Many recent innovations, especially iterative reconstruction solutions, reflect this. They were explicitly developed to lower the applied dose. So it follows to introduce a detector that is specially optimized for low-signal imaging: the Stellar Detector with TrueSignal Technology.
TrueSignal Technology TrueSignal Technology with the full integration of the Stellar Detector virtually eliminates electronic noise in the detector elements. The resulting SNR is increased so that even very low signals are sufficiently strong enough for the detector to cope with. Low-signal images benefit from increased sharpness and clarity, as the detector can now differentiate the signal of an individual voxel much better than the surrounding image data.
SOMATOM Definition Edge
40 cm fit
40 cm fit
at 200 mA
at 300 mA
at 400 mA
Comparable noise level at lower signal The outcome can be best visualized when looking at noise measurements of large patients. When comparing conventional CT technology with the SOMATOM Definition Edge and the Stellar Detector with TrueSignal Technology, the resulting noise is more or less the same for high signals. But when the signal is lowered – either by high attenuations from obese or broadshouldered patients, or by reducing the applied mA – the impact of TrueSignal Technology increases.
Dose savings at the same noise level with SOMATOM Definition Edge
Due to minimized electronic noise, the available signal is less impaired, so that the same noise level can be achieved with significantly lower signal levels. This means that when there is high attenuation from very large patients, the detector can make better use of the resulting low signal. Or, the dose can be further reduced to achieve a comparable image quality.
25% Dose reduction in low-signal imaging
More and more patients suffer from obesity. Therefore, the capability to deliver sound bariatric imaging is essential for state-of-the-art CT imaging.
Obesity – the new global disease One example of how reducing electronic noise with TrueSignal Technology benefits low-signal efficiency is bariatric imaging. Obesity is on the rise: In the US and some European countries, more than 1/3 of the population is considered obese. Therefore, there is a growing need to scan large patients. However, obese patients attenuate a significant portion of the signal, so regardless of scanner ergonomics, many conventional CT systems are unsuitable, as the signal is too low.
Optimized bariatric imaging By minimizing electronic noise, the detector’s SNR increases, providing much more flexibility in handling low signals. This is essential for bariatric imaging, as often maximum power is applied, but the signal reaching the detector is very low. Conventional detectors have a comparatively high intrinsic noise level and impaired image quality. Due to the electronic integration of the Stellar Detector, this noise level is significantly lower, so the available signal can be processed more efficiently.
State-of-the-art CT systems have to react to the new challenges presented by the increasing number of bariatric patients. This means having the appropriate ergonomics to handle these patients, as well as having the technology to achieve the image quality necessary for reaching sound diagnoses. The SOMATOM Definition Edge delivers the ideal solution with a 78 cm gantry bore, and a table load capacity of more than 300 kg, all enhanced by the new Stellar Detector with TrueSignal Technology.
collimation: 64 x 0.6 mm spatial resolution: 0.33 mm scan time: 1.5 sec scan length: 155 mm rotation time: 0.5 sec CTDIvol: 21 mGy DLP: 325 mGy cm eff. dose: 4.55 mSv
Conventional detector technologies have difficulties handling low signals, resulting, for example, in streak artifacts (left). With its higher SNR, the Stellar Detector is perfectly designed to cope with low signals (right).
60% Dose reduction with SAFIRE
* The following test method was used to determine a 60% dose reduction when using the SAFIRE reconstruction software: Noise, CT numbers, homogeneity, low-contrast resolution and highcontrast resolution were assessed in a Gammex 438 phantom. Low-dose data reconstructed with SAFIRE showed the same image quality compared to full-dose data based on this test. Data on file.
Low dose is low-signal imaging The significant reduction of mA when scanning with iterative reconstruction solutions like SAFIRE (Sinogram Affirmed Iterative Reconstruction) also results in lower signals at the detector, so these examinations also benefit from the advantages of TrueSignal Technology. The computational power of systems like FAST IRS fascilitate iterative reconstruction in a wider range of clinical applications. The number of iterative reconstruction scans is thereby increased, resulting in more benefits for patients.
Iterative reconstruction After the initial reconstruction using weighted filtered back projection (WFBP), the CT images are retransferred to raw data. By comparing this new synthetic raw data with the acquired data, differences can be identified by applying a dynamic raw-data based noise model. An updated image is then reconstructed, with reduced image noise but without noticeable loss of sharpness. This is repeated several times – image noise can be incrementally reduced and geometrical imperfections corrected.
SAFIRE and the Stellar Detector Superior image quality in regard to contrast and noise can be obtained with this methodology. And it can be used to initially acquire the data at lower mA and then compensate the image quality during the reconstruction. By using this approach, SAFIRE enables a dose reduction of up to 60%.* This reduction in dose means a lower signal at the detector. So now unique lowsignal capabilities of the Stellar Detector further optimize the image quality, resulting in even higher sharpness and clarity.
collimation: 128 x 0.6 mm spatial resolution: 0.33 mm scan time: 11 sec scan length: 245 mm rotation time: 0.5 sec CTDIvol: 8.5 mGy DLP: 460 mGy cm eff. dose: 6.9 mSv
Significantly improved image quality at lower dose using SAFIRE with the Stellar Detector (right) compared to a regular WFPB on a conventional detector (left).
60% Dose reduction with CARE kV
The main dose-relevant parameters for a CT scan are the applied current and voltage, depending on the examination type and the patient's habitus. Only when taking all parameters into consideration, does dose protection become comprehensive and patient-centric.
Real time dose modulation In 1994, Siemens introduced CARE Dose4DTM to actively modulate the applied power for scans, according to patients’ anatomy. CARE Dose4D aims to regulate mA in real time so that image quality is uniform across the whole scan range. But CT scanning is not only adapting mA values: The right kV settings play an equal if not more important role in achieving optimum clinical outcome. Changing kV values also means adapting all other values according to the respective patient and examination type.
CNR optimized kV settings After the patient’s stature and the mAs, the selected voltage (kV) is the third doserelevant value for a CT scan. Selecting the right kV settings is essential for achieving optimal clinical outcome. CARE kV can automatically suggest kV and effective mA to optimize the contrast-to-noise ratio (CNR) of the image, while limiting the applied dose. CARE kV takes the patient’s habitus from the topogram and the chosen examination type (non-contrast, bone, soft tissue, vascular) into consideration, proposes the appropriate
kV, and sets all other parameters accordingly to get the defined CNR. Reducing the tube voltage helps optimizing dose and improves image quality, e.g., for contrast-media enhanced examinations. With the new, improved STRATON tube, the voltage range is lowered to 70 kV. This, together with the unique CARE Child scan modes, helps further reduce the dose for pediatric or neonate patients. With these features, an additional dose reduction of up to 60% is possible. Additionally, the system identifies bariatric
kV usage [%]
Without CARE kV
80 70 60
With CARE kV
50 40 30 20 10 0
patients and sets the parameters accordingly to make full use of the system’s reserves to optimize CNR, and achieve the best image quality possible for these patients.
Benefit for many patients An evaluation of CARE kV with more than 12,000 patients in the first months after its introduction showed that there was a clear shift towards 100 kV and 80 kV scans (see above). Dose could be saved in more than two thirds of these patients, compared to the initial protocols. And the dose reduction itself was significant. For example, regular abdomen scans could be reduced to below 10 mGy using 100 kV, down from 14.1 mGy with the former standard protocol set at 120 kV. This dose reduction of approximately
Tube voltage [kV]
Lower dose in 67% of patients with CARE kV
30% came with no compromise in image quality; CNR could be maintained with no impact on workflow, as all system parameters are automatically set.
Combined Applications to Reduce Exposure (CARE)
Dose reduction lies at the heart of the CARE philosophy. Each application is designed to contribute dose reduction during every step of the examination process resulting in an absolute minimum exposure.
Radiation exposure 9 [mSv] 8
Dose reduction in cardiac CT
7 6 5 4 3 2 1 0
Adaptive ECG Pulsing
Adaptive Dose Shield
Comprehensive dose protection Following the ALARA principle, Siemens introduced its CARE philosophy in the mid-1990s. The idea is to utilize every means available to reduce patient exposure. Siemens is the only vendor to offer a dose protection portfolio that comprehensively takes all relevant scan parameters into consideration and optimizes the scan accordingly, from patient size to examination type, from mA to kV, and from scan preparation to data evaluation.
collimation: 128 x 0.5 mm spatial resolution: 0.30 mm temp resolution: 142 msec scan time: 5 sec scan length: 119 mm rotation time: 0.28 sec CTDIvol: 7 mGy DLP: 95 mGy cm eff. dose: 1.33 mSv
Cardiac examinations are amongst the most sensitive when it comes to dose, so combining all available applications to reduce exposure is key.
Specify the Unspecific
Specify the Unspecific The TrueSignal Technology of the Stellar Detector brings yet another innovation: HiDynamics. Its unique, full dynamic range provides higher image sensitivity, especially for low-signal and low-energy scans.
A larger dynamic range expands the detector’s sensitivity. As in a backlit photo with a conventional camera, the front regions turn black. But with higher sensitivity, details remain visible.
HiDynamics Thanks to the full electronic integration of the TrueSignal Technology, the Stellar Detector can now utilize its full dynamic range instead of having to switch bandwidth like conventional detectors. This unique feature is called HiDynamics. It increases the detector’s sensitivity at the respective energy level and allows for differentiation of even the slightest signal changes, especially when scanning with very low kV levels.
Comparison of the 80 kV Dual Energy data set (left) with the 140 kV Dual Energy data set (right) shows: almost identical image detail level in 80 kV due to the improvement resulting from HiDynamics.
The benefits of the Stellar Detector The benefits of TrueSignal Technology and HiDynamics are also clear in functional imaging applications, such as Dual Energy, as well as in dynamic examinations. They acquire multiple scans of the same region to add functional information, such as tissue characteristics or perfusion data to the morphology. In both cases, the scan modes acquire data at low kV. HiDynamics significantly increases the detail level and sharpness of the images for these data sets.
Dose-optimized Single Source DE When multiple scans of the same region have to be performed, dose protection becomes even more important in order to adhere to the ALARA principle. Therefore, it is imperative to exploit every possibility to reduce dose. Following this philosophy, Siemens has introduced a Single Source Dual Energy scan mode that utilizes all dose-reduction functionalities without limitations: e.g., CARE Dose4D for real-time mA modulation, or SAFIRE to reduce the mA created by iterative reconstruction.
The scan mode consists of two successive spiral scans at different energy levels. In order to avoid doubling the dose, both spirals are performed at half the dose, so that there is no dose penalty for the resulting Dual Energy image. But, as it uses regular spirals, all dose reduction features can be utilized without limitations. The capabilities of the Stellar Detector regarding low dose / signal imaging represents the industry’s only Single Source Dual Energy scan mode optimized for low dose.
Calculi characterization in clinical routine
Kidney stones are a good example of how tissue characterization can lead to finding the appropriate therapy. Dual Energy information adds tissue information to the morphology.
Urinary stone disease Approximately 13% of men and 7% of women in the United States will be diagnosed with urinary stone disease in their lives. Most stones are symptomatic and cause pain, obstruction, and infection. They frequently require visits to the emergency room, hospitalization, mechanical extraction or even surgical removal. Some stones may be asymptomatic and are only detected incidentally. However, even when stones are initially asymptomatic, symptoms may develop very quickly and
require intervention later. Current evidence from the study “Urological Diseases in America” suggests an increasing prevalence of urinary stone disease in the United States. In addition, the likelihood of recurrence is estimated to be up to 50 % during a five-year period. Thus, the diagnosis of kidney stones has substantial impact with respect to patient morbidity and healthcare budgets. The imaging modality of choice for urinary stone disease is a low-dose, noncontrast CT scan. It is very easy to perform,
does not require intravenous contrast and covers the entire abdomen and pelvis. With this imaging modality, nearly all stone types can be visualized. The essential benefit in the diagnosis with Dual Energy CT is that the stone type can be identified. With this information at hand, the appropriate treatment can be applied. For patients, this means that many interventional treatments can be avoided, as it can be determined upfront if a stone can be treated with drugs or not.
collimation: 128 x 0.6 mm spatial resolution: 0.33 mm scan time: 1.3 sec scan length: 117 mm rotation time: 0.5 sec CTDIvol: 5.28 + 3.02 mGy (140 / 80 kV) DLP: 80 + 40 mGy cm (140 / 80 kV) eff. dose: 1.8 mSv
Characterization with syngo Single Source DE Kidney Stones supports treatment decisions.
Gout identification in clinical routine
Gout is the most widespread form of crystal arthropathy and a common inflammatory joint disease. However, gout is difficult to diagnose. Dual Energy can detect gout in regions that are often overlooked.
Gout Gout is the most widespread form of crystal arthropathy and the most common inflammatory joint disease in men. It is caused by the deposition of uric acid crystals in joints. Up to 1 in 200 people in the western world, 2.1 million people in the US, and some 1.5 million people in Germany are currently afflicted by this painful, destructive disease. Furthermore, due to our eating habits, these figures are constantly increasing. Gout can affect numerous joints throughout the body, especially during
recurrent episodes. The classic symptoms of gout are painful, visibly swollen peripheral joints. However, gout is difficult to diagnose, as there are various forms of arthritis that have similar symptoms. With Dual Energy CT and syngo® Dual Energy Gout, a non-invasive assessment of gout is feasible. The algorithm color codes different attenuation values at different energy levels so that the uric acid crystals are color coded in red, while calcium and bone formations are displayed in blue. Thus, uric acid pro-
duced by the disease is directly verified, confirming the definite diagnosis of gout. The benefit for patients is not only that the painful puncture in a conventional examination can be avoided, but also that the risk of false negative outcomes is reduced in cases where the puncture misses the respective tissue.
collimation: 128 x 0.6 mm spatial resolution: 0.33 mm scan time: 4 sec scan length: 181 mm rotation time: 0.5 sec CTDIvol: 3.32 + 4.46 mGy (140 / 80 kV) DLP: 71 + 95 mGy cm (140 / 80 kV) eff. dose: 0.13 mSv
Clear identification with syngo Single Source DE Gout avoids false negative diagnosis of conventional procedures.
Reducing metal artifacts in clinical routine
Metal artifacts pose severe difficulties in CT imaging due to the resulting artifacts. Single Source Dual Energy now delivers a solution.
Metal artifact reduction with Dual Energy A big challenge in CT imaging is the impact of metal objects on image quality. Due to the high attenuation of metal compared to the surrounding tissue, images can suffer from streaks or even shadows around the metal objects. The cause for this is so-called ‘beam starvation.’ Typical metal artifacts result from implants, e.g., in teeth, or when clamps and screws are used in invasive treatments. But when it comes to treatment decisions or treatment follow-up, it is essential that the image is as
artifact free as possible. For example, when assessing organs in the pelvic region, images are often impaired if the patient has a hip prosthesis. The high attenuation of this massive metal object causes adjoining regions to suffer from very low signals. Until now, these artifacts could not be compensated for. But now, two solutions come together: The unique Stellar Detector in the SOMATOM Definition Edge is specifically optimized to handle low signals with its TrueSignal Technology and HiDynamics.
And syngo Dual Energy Monoenergetic Imaging enables the minimization of metal artifacts by specifically selecting the respective kV level at which the metal objects have least impact on image quality. With this unique combination, implants, clamps or screws can be ideally dealt with in order to obtain the highest diagnostic outcome.
collimation: 128 x 0.6 mm spatial resolution: 0.33 mm scan time: 5 sec scan length: 228 mm rotation time: 0.5 sec CTDIvol: 12.31 + 4.46 mGy (140 / 80 kV) DLP: 380 + 129 mGy cm (140 / 80 kV) eff. dose: 7.64 mSv
Significant reduction of metal artifacts from hip implant with syngo Single Source DE Monoenergetic delivers much higher diagnostic image quality
Improved dynamic imaging in clinical routine
Perfusion information is crucial in many clinical fields such as stroke or tumor assessments. The Adaptive 4D Spiral is key to making these exams ready for clinical practice.
Stroke is one of the three most frequent causes of death worldwide. The diagnosis and treatment of stroke cases is a clinical field in which time is of the essence – or where ‘time is brain,’ meaning that the right decisions have to be made ideally within the first hours after the first symptoms have occurred. Consequently, it is essential that the diagnostic information is delivered quickly, reliably, and accurately, and gives a comprehensive overview about the status of the disease.
Adaptive 4D Spiral and HiDynamics With the Adaptive 4D Spiral, Siemens has introduced a scan mode that performs perfusion evaluations beyond the limitations of a static detector. By applying a continuously repeated bi-directional, smooth table movement over the desired scan range, a perfusion assessment covering a region of up to 15 cm can be performed. Recent publications have shown that a scan range of approximately 10 cm is ideal to assess brain perfusion. Consequently, the neuro perfusion scan modes with the Adaptive 4D
Spiral are specifically set to this length for stroke evaluations. In addition, the SOMATOM Definition Edge, with the Stellar Detector and HiDynamics, is the perfect choice for better differentiation of the perfusion level, as brain perfusion studies are typically performed at 80 kV. Regardless of cause – from infarctions due to stroke and extensive bleeding, to subarachnoid hemorrhage or a ruptured aneurysm – seeing clearly makes a crucial difference in determining treatment.
collimation: 128 x 0.6 mm scan time: 45 sec scan length: 100 mm rotation time: 0.285 sec CTDIvol: 260 mGy DLP: 3069 mGy cm eff. dose: 6.4 mSv
Comprehensive perfusion evaluation with syngo VPCT Neuro delivers crucial information regarding tissue at risk after a stroke.
SOMATOM Definition Edge The Reference in Single Source CT See the unseen Edge Technology – The reference in image quality • Unprecedented spatial resolution • Uncompromised temporal resolution • Unparalleled acquisition speed Get more from less TrueSignal Technology – The reference in dose efficiency • Optimized low-signal imaging • Optimized low-dose imaging • Optimized patient-centric imaging Specify the unspecific HiDynamics – The reference in functional imaging • Routine ready Single Source Dual Energy • Routine ready metal artifact reduction • Routine ready dynamic imaging
Technical Specifications • Stellar Detector with TrueSignal Technology • 256 x 0.5 mm slices and 0.30 mm spatial resolution with Edge Technology • Dose-optimized Single Source Dual Energy and HiDynamics • 128-slice acquisition with STRATON tube and z-Sharp Technology • Up to 384-slice reconstruction • 0.28 sec rotation time with 142.5 sec temporal resolution • 1.7 maximum pitch with 230 mm/sec acquisition speed • Patient table: 227 kg capacity (300 kg optional), 200 cm scan range • With up to 60 fps FBP and 20 fps SAFIRE reconstruction speed • 4D scan range: 15 cm for perfusion, 48 cm for CTA imaging with Adaptive 4D Spiral • Reduced energy consumption by up to 20% in system stand-by with the Stellar Detector
In the event that upgrades require FDA approval, Siemens cannot predict whether or when the FDA will issue its approval. Therefore, if regulatory clearance is obtained and is applicable to this package, it will be made available according to the terms of this offer. On account of certain regional limitations of sales rights and service availability, we cannot guarantee that all products included in this brochure are available through the Siemens sales organization worldwide. Availability and packaging may vary by country and is subject to change without prior notice. Some/all of the features and products described herein may not be available in the United States. The information in this document contains general technical descriptions of specifications and options as well as standard and optional features which do not always have to be present in individual cases. Siemens reserves the right to modify the design, packaging, specifications, and options described herein without prior notice. Please contact your local Siemens sales representative for the most current information. Note: Any technical data contained in this document may vary within defined tolerances. Original images always lose a certain amount of detail when reproduced.
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SOMATOM Definition Edge is under development, and is not commercially available in the US. The information about SAFIRE (Sinogram Affirmed Iterative Reconstruction) is being provided for planning purposes. The product is pending 510(k) review, and is not yet commercially available in the US. In clinical practice, the use of SAFIRE may reduce CT patient dose depending on the clinical task, patient size, anatomical location, and clinical practice. A consultation with a radiologist and a physicist should be made to determine the appropriate dose to obtain diagnostic image quality for the particular clinical task.
Courtesy list Department of Radiology, University of Erlangen, Germany Mayo Clinic, Rochester (Minnesota), USA Nan Xi Shan Hospit al / Guilin, P.R. China Beihua University 1st Hospital / Jilin, P.R. China
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