{"id":56,"date":"2025-11-28T01:24:24","date_gmt":"2025-11-27T16:24:24","guid":{"rendered":"http:\/\/rad.med.keio.ac.jp\/eng\/?page_id=56"},"modified":"2026-01-20T14:57:59","modified_gmt":"2026-01-20T05:57:59","slug":"upright-ct","status":"publish","type":"page","link":"http:\/\/rad.med.keio.ac.jp\/eng\/diagnostic-radiology\/upright-ct\/","title":{"rendered":"Upright CT and Multi-Position CT"},"content":{"rendered":"\n

Development and Clinical Application of Upright CT and Multi-Position CT<\/span>
\u2013 Aiming to Extend Both Lifespan and Healthy longevity\u2013<\/span><\/h2>\n\n\n\n

Background<\/strong><\/h3>\n\n\n\n

Shortening of scanning time through CT scan speed improvement<\/strong><\/h4>\n\n\n\n

Since its invention in the 1970s, CT has traditionally been performed only in the supine position. Around the year 2000, the advent of multi-detector CT enabled faster, wider-range, and higher-resolution imaging. Earlier single-detector CT scanners required several minutes to scan the whole body, making it difficult for patients to remain still in an upright posture. With the faster acquisition speed of multi-detector CT, the trunk can now be routinely imaged in less than 20 seconds. Observing this in daily clinical practice, we realized that CT had reached a speed that could allow imaging even in the standing position.<\/p>\n\n\n\n

Growing importance of functional assessment<\/strong><\/h4>\n\n\n\n

Conventional supine CT has contributed to prolonging life expectancy by enabling diagnosis of organic diseases such as infections, cancers, and arteriosclerosis. Around 2007, Japan entered a super-aged society, and in addition to extending lifespan, the importance of detecting functional disorders at an early stage to extend healthy longevity <\/em>became widely recognized. Many functional disorders\u2014such as those related to swallowing, urination, and gait\u2014cannot be assessed in the supine position. Therefore, we thought imaging in the standing or sitting position was essential.<\/p>\n\n\n\n

Development Process of Upright and Sitting CT<\/strong><\/h4>\n\n\n\n

In 2012, Professor Masahiro Jinzaki<\/strong> of Keio University proposed to Toshiba Medical Systems (now Canon Medical Systems<\/strong>) the development of a CT scanner capable of both supine and upright\/sitting imaging (Figs. 1-3), taking advantage of the advances in CT speed. Emphasizing the clinical significance of upright CT as an imaging modality for an era focused not only on lifespan but also on healthy longevity, repeated discussions and negotiations led to the project being finally approved in 2014.<\/p>\n\n\n\n

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Fig.1 Schematic of the CT system we initially proposed, capable of imaging in the supine, standing, and sitting positions<\/figcaption><\/figure>\n\n\n\n
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Fig.2 Conceptual drawing of the upright CT at the start of project launch.<\/figcaption><\/figure>\n\n\n\n
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Fig.3 Launch of the upright CT project. Gantry size determined using cardboard at Keio University Hospital.<\/figcaption><\/figure>\n<\/div>\n\n\n\n

From 2015, Professor Jinzaki, together with Dr. Takeo Nagura<\/strong> (Department of Orthopedic Surgery) and Professor Naomichi Ogihara<\/strong> (Faculty of Science and Technology, Keio University), held bimonthly meetings to refine the design concept. As a result, the team decided first to develop a CT scanner capable solely of upright and sitting imaging. The world\u2019s first such prototype was completed at the end of 2016 (Figs. 4 and 5).<\/p>\n\n\n\n

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Fig.4 Prototype unveiling at the Canon Medical Systems Nasu Plant.
Center: Masahiro Jinzaki, left: Takeo Nagura, right: Naomichi Ogihara, and Canon Medical staff on both sides.<\/figcaption><\/figure>\n\n\n\n
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Fig. 5 The first CT machine developed that enabled imaging in both the standing and sitting positions<\/figcaption><\/figure>\n<\/div>\n\n\n\n

Clinical Research Using Upright and Sitting CT<\/strong><\/h3>\n\n\n\n

In May 2017, the first upright\/sitting CT unit was installed at Keio University Hospital. Under Professor Jinzaki\u2019s leadership, a research group was organized, including Associate Professor Yoshitake Yamada<\/strong>, Dr. Minoru Yamada<\/strong>, Assistant Professor Yoichi Yokoyama<\/strong>, and Dr. Nagura<\/strong>. A specific clinical research program was launched using this system.<\/p>\n\n\n\n

Collaborations extended across multiple departments\u2014including neurosurgery, respiratory medicine, thoracic surgery, cardiology, cardiac surgery, gastroenterology, general surgery, urology, gynecology, orthopedics, and plastic surgery\u2014to elucidate human anatomical structures under gravity and to reveal organ positional shifts dependent on posture. Numerous reports have demonstrated the clinical utility of this system, including the visualization of disease conditions unrecognizable on conventional supine CT.<\/p>\n\n\n\n

Advantages of upright imaging include:<\/strong><\/h4>\n\n\n\n
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  • Improved examination workflow<\/li>\n\n\n\n
  • Fully contact-free and remotely operated scanning, reducing infection risk<\/li>\n\n\n\n
  • Diagnosis of posture-dependent symptoms or abnormalities that appear only when standing<\/li>\n\n\n\n
  • Early detection of load-bearing musculoskeletal disorders<\/li>\n\n\n\n
  • Assessment of pelvic floor relaxation<\/li>\n\n\n\n
  • Longitudinal evaluation of posture and muscle mass<\/li>\n\n\n\n
  • Functional assessment of swallowing, gait, and urination<\/li>\n\n\n\n
  • Application to sitting-position radiotherapy<\/li>\n<\/ul>\n\n\n\n

    Following its introduction at the Keio University Hospital main campus in 2017 (Fig. 6), the system was also installed at the Keio University Preventive Medicine Center<\/strong> in 2023, where it is now being utilized for preventive care aimed at extending healthy longevity.<\/p>\n\n\n\n

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    Fig. 6. Installation of the first clinical unit. Front row center: Canon Medical Systems President Toshio Takiguchi and Masahiro Jinzaki; left: Naomichi Ogihara; right: Takeo Nagura. Back row in white coats, from right: Yoshitake Yamada, Takehiro Nakahara, Minoru Yamada, Yoichi Yokoyama.<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

    Development of Multi-Position CT<\/strong><\/h3>\n\n\n\n

    Around 2020, in parallel with the clinical studies of the upright\/sitting CT, the team\u2014together with Canon Medical Systems\u2014continued regular meetings to pursue the original goal: a multi-position CT system<\/strong> capable of imaging in the supine, sitting, and standing positions (Fig. 7).<\/p>\n\n\n\n

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    Fig. 7. Conceptual design of the multi-position CT mechanism using cardboard mock-ups.<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

    To achieve this, the system adopted a cantilever-type gantry structure<\/strong>, supported from one side instead of both, ensuring stability and openness. For enhanced patient safety and usability, infrared area sensors<\/strong> were incorporated to detect abnormal movements, and a mechanism allowing the gantry to tilt 14 degrees forward<\/strong> was developed to facilitate patient entry in the standing position.<\/p>\n\n\n\n

    In 2025<\/strong>, the multi-position CT \u201cAquilion Rise\u201d<\/strong> was officially released, capable of scanning in all three positions\u2014standing, sitting, and supine (Figs. 8 and 9). The world\u2019s first clinical unit was installed at Keio University Hospital, where ongoing clinical studies are underway.<\/p>\n\n\n\n

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    Fig.8  The first clinical unit of the multi-position CT system <\/figcaption><\/figure>\n<\/div>\n<\/div><\/div>\n\n\n\n
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