Home
Perspectives
- A history rich in innovation
A history rich in innovation
From head to toe (1971鈥1980)
The history of computed tomography at Siemens began when the heads of development went on a trip to London in 1972. Later the same year, a CT development department was established in the fundamental research unit at Siemens in Erlangen 鈥 and Siemens went on to launch its first CT scanner in 1975. The SIRETOM head scanner acquired two tomographic images of the brain per scan in close to five minutes. Just two years later, a head scan using a Siemens whole-body scanner took just five seconds 鈥 and it was also possible to examine the chest, abdomen, and joints.
Sir Godfrey Hounsfield, the inventor of computed tomography.
Scan of the cranium using the prototype Siemens unit, 1974.
Measurement system of SIRETOM, 1974.
Control panel of SIRETOM at Goethe University Medical Center in Frankfurt, Germany.
Contrast agent-free scan of the abdomen with SOMATOM, 1977.
Preparing for an examination with SOMATOM 2, 1979.
Sir Godfrey Hounsfield, the inventor of computed tomography.
Changing times (1981鈥1990)
The significantly higher speed resulted in significantly more data, which Siemens transmitted using an optoelectronic system. Other components of SOMATOM Plus were also adapted to the higher speeds 鈥 for example, the X-ray tube had twice the output of previous tubes and cooled down much faster.
Image showing a carcinoma of the lung, 1980.
Slip ring technology in SOMATOM Plus, 1987.
Scan of the abdomen, 1988.
A paradigm shift (1991鈥2000)
From the mid-1990s onward, it was possible to visualize the vast quantities of data generated by spiral CT in 3D for the first time. Also unique were the Ultra Fast Ceramic (UFC) detectors, which replaced the xenon gas of earlier systems and absorbed the X-rays almost entirely, converting them into electrical signals in a relatively loss-free manner. In conjunction with increasingly advanced software, this technology also brought significant reductions in radiation dose.
In 1998, Siemens took another key step forward with the introduction of multislice CT. This technology split the detector into multiple rows, which processed signals from the X-ray tube independently of one another and could therefore record multiple slices per rotation. The system was able to visualize whole organs in high definition 鈥 including, for the first time, the coronary vessels.
The world鈥檚 first spiral CT scanner, SOMATOM Plus-S, 1991.
Lung scan with SOMATOM Plus 4, 1997.
Presentation of SOMATOM Volume Zoom at RSNA 1998.
Image of the coronary vessels at University Hospital Munich (LMU), Germany, 1999.
Major advances (2000鈥2010)
At the same time, heat generation during long scans placed a burden on the X-ray tube, and the pivot bearings were subject to considerable mechanical strain. The answer was to develop a rotating envelope tube known as the Straton X-ray tube. In this design, the entire vacuum tube rotated and was therefore much more robust and compact. It also discharged about ten times more heat.
In order to usher in a technological revolution, it was then necessary to completely redesign the basic framework of the CT scanner: the first Dual Source CT with two tube-detector systems. Instead of rotating through 180 degrees per slice in order to collect the necessary data, SOMATOM Definition needed to rotate through just 90 degrees. This, in conjunction with a rotation time of just 0.33 seconds, lead to a temporal resolution of just 0.083 seconds, for example to produce pin-sharp images of the beating heart.
Comparison of a conventional CT tube (right) with Straton (left), 2004.
Heart scan with SOMATOM Sensation Cardiac 64, 2004.
The first Dual Source CT scanner: gantry production for SOMATOM Definition, 2006.
Dual Source CT: the skull, cervical spine, and carotids of a 59-year-old man, 2006.
Dual energy technology produces two datasets containing different information in a single scan. Scan of the foot, University Hospital Munich (LMU), Germany, 2007.
Pushing technology to its limits (2011鈥2020)
SOMATOM Force has ultimately pushed all the high-end components from Siemens Healthineers to their limits. Weighing in at 1.6 tons, its gantry rotates around the patient four times per second and achieves a resolution of 0.24 millimeters and the radiation exposure for a lung scan, for example, is 0.1 millisievert.
The engineers are developing new tools in order to make constructive use of this huge quantity of three-dimensional data. One need only look at Cinematic Rendering images to get an idea of the capabilities of sophisticated image processing software. At the same time, artificial intelligence is gaining a foothold in CT imaging 鈥 helping users not only to prepare for scans but also to evaluate the results: myExam Companion helps them achieve optimum scan preparation, and AI-Rad Companion Chest CT1 can relieve the burden on radiologists when it comes to interpreting medical images.
A conventional detector element (top) and a Stellar detector element (bottom), 2012.
A dual energy scan with SOMATOM Definition Edge, University Hospital Erlangen, Germany, 2014.
SOMATOM Force in Mannheim, Germany, 2013.
In combination with an increased table speed of 73.7 centimeters per second, SOMATOM Force can scan an adult鈥檚 entire upper body in less than a second. Mannheim University Medical Centre, Germany, 2013.
Thyroid gland and bones of the head and neck region visualized with Cinematic Rendering in 2015. Radiology department at the Jewish Hospital in Hamburg, Germany.
A conventional detector element (top) and a Stellar detector element (bottom), 2012.
Every X-ray photon counts (Since 2021)
By the late 2010s, computed tomography (CT) had become so advanced that there was almost no room for improvement in the performance of conventional systems. For reasons relating to physics, the technical potential had been practically exhausted. Image quality could no longer be significantly increased using conventional technology, and there was no scope for further reducing the radiation dose. In the past, Siemens Healthineers had circumvented these kinds of physical limits with inventions such as spiral CT and Dual Source CT 鈥 and the next big advance would also call for a completely new approach.
As early as 2001, a team from the basic research department of Siemens Healthineers began working on a future CT technology. There was one novel detector material in particular that could potentially raise the standard of computed tomography in one fell swoop: crystals of cadmium telluride, which convert X-ray photons directly into electrical signals with no loss of information. These 鈥減hoton-counting detectors鈥 essentially 鈥渃ount鈥 each individual X-ray photon that passes through a patient鈥檚 body 鈥 and simultaneously measure the photon鈥檚 energy. Over the next 20 years, the steadily growing team behind the project developed many new technologies and applied for over 500 patents relating to photon-counting CT. In fall 2021, the world鈥檚 first photon-counting CT scanner was finally ready for clinical use, and Siemens Healthineers presented NAEOTOM Alpha to the public on November 16, 2021. Many experts spoke of a reinvention of computed tomography. Reports from the first users included phrases such as 鈥渢ruly incredible鈥 and a 鈥渜uantum leap,鈥 and claimed that photon-counting technology would 鈥渃atapult computed tomography into a new era of medicine.鈥
Recorded with NAEOTOM Alpha, 20221, Courtesy of Erasmus Medical Center, Rotterdam, Netherlands.
Two years after NAEOTOM Alpha was presented, photon-counting CT had already been used to scan over 500,000 people 鈥 a figure that, according to Siemens Healthineers, was set to rise to a billion over the next 10 years. 鈥淭he future is photon-counting,鈥 said Philipp Fischer, head of computed tomography at Siemens Healthineers. 鈥淲e鈥檙e ready to move into a broader market and to take the next step in our ambition to positively impact millions of patients鈥 lives.鈥 At the Annual Meeting of the Radiological Society of North America (RSNA) in 2024, Siemens Healthineers presented the NAEOTOM Alpha class, with which it hopes to make photon-counting technology accessible to more clinicians and patients. 鈥淲e鈥檙e taking a major step into the future with the introduction of the NAEOTOM Alpha class, extending photon-counting technology further across our portfolio,鈥 says Fischer. 鈥淲e believe that every CT scanner will be a photon-counting CT scanner by 2040.鈥
Siemens Healthineers presented NAEOTOM Alpha.Prime, the first single source photon-counting CT scanner, at RSNA 2024.
The high speed of NAEOTOM Alpha.Pro enables complex examinations, such as those where patients have to hold their breath during the scan.1
Share this page
1 Cinematic VRT is recommended for communication, education, and publication purposes and not intended for diagnostic reading.
The product/feature and/or service offerings mentioned herein are not commercially available in all countries and/or for all modalities. Their future availability cannot be guaranteed.
The statements by customers of Siemens Healthineers described herein are based on results that were achieved in the customer's unique setting. Because there is no 鈥渢ypical鈥 hospital or laboratory and many variables exist (e.g., hospital size, samples mix, case mix, level of IT and/or automation adoption) there can be no guarantee that other customers will achieve the same results.