Technology overview

This briefing describes the regulated use of the technology for the indication specified, in the setting described, and with any other specific equipment referred to. It is the responsibility of healthcare professionals to check the regulatory status of any intended use of the technology in other indications and settings.

About the technology

CE marking

The Aquilion PRIME (Toshiba Medical Systems) was originally launched in the UK in 2011. It has a CE marking as a class IIb device under the Medical Devices Directive 1993/42/EEC. This was renewed on 26 February 2015 after a hardware modification.


The Aquilion PRIME (Toshiba Medical Systems) is a helical (rotating with a constant radius) CT scanner with the following main features and specifications:

  • Single‑source: a single X‑ray source within the scanner gantry.

  • Multi‑slice: capable of imaging multiple parallel, cross‑sectional slices in a single rotation.

  • Dual‑energy: images are acquired at 2 different energies to allow differentiation between tissues.

  • 78 cm bore (aperture diameter) with a couch that can be driven low to the ground, a table weight limit of 300 kg and lateral movement capability, which allows the patient to be positioned accurately.

Table 1 Technical specifications

Technical specification

Aquilion PRIME

1. X‑ray output

a. X‑ray generator power

72 kW

b. Tube potential of 100 kV

i. Maximum tube current

600 mA

ii. CTDIw/100 mA

13.9 mGy

c. Tube potential of 120 kV

i. Maximum tube current

600 mA

ii. CTDIw/100 mA

22.5 mGy

2. Volume coverage

a. Detector rows

80 proprietary PUREViSION scintillator array)

b. Detector row size

0.5 mm

c. z‑axis length

40 mm

d. Number of slices per rotation

80 (160 slices can be generated with a reconstruction algorithm)

3. Temporal resolution

a. Minimum gantry rotation time

350 ms

b. Intrinsic temporal resolution

175 ms

c. Effective temporal resolution

35–175 ms

4. Spatial resolution

a. Detectors per row


b. x‑y plane spatial resolution (standard mode)

0.45 mm

c. x‑y plane spatial resolution (high resolution mode)

0.39 mm

d. z‑width of detector row

0.5 mm

e. z‑spatial resolution

0.45 mm

Abbreviations: CDTIW, CT dose index weighted (the average absorbed dose across the field of view in a standard phantom); kV, kilovolt; kW; kilowatt; mA, milliamp; mGy, milligray; mm, millimetre; ms, millisecond.

According to the manufacturer, the Aquilion PRIME includes the following software and capabilities, which are claimed to improve cardiac CT scanning in people in whom imaging is difficult:

  • Dose reduction and image quality

    • Adaptive Iterative Dose Reduction (AIDR 3D): noise reduction technology, enabling a lower radiation dose and less contrast medium to be used, while improving image detail. AIDR 3D is also designed to minimise artefacts to improve image quality in computed tomography coronary angiography (CTCA) for people with grafts or obesity.

    • SUREExposure 3D: adjusts exposure in the x, y and z directions in response to a person's shape and size, thus reducing radiation exposure. The algorithm calculates the amount of tube current needed to achieve the target image quality specified by the user. This may be particularly beneficial for people with obesity.

    • SUREkV: automatically sets the tube potential (the energy and intensity of the X‑ray beam) based on the person's size, SUREExposure settings and generator capacity. Lowering the kV optimises the contrast within the image, thereby reducing the amount of additional contrast medium needed. This feature intends to standardise image quality for people of varying size and may be particularly beneficial in people with obesity. It could also reduce the risk of contrast‑related adverse events.

  • Gating functionality (selective imaging at specific points in the cardiac cycle)

    • SURECardio: prospective software which rapidly pulses the X‑rays on and off, so the person is only exposed to radiation during the cardiac phase or the phases needed for the diagnostic procedure. If an irregular heart rhythm is detected, the software will automatically set optimal scanning conditions to ensure good image acquisition. This may be beneficial for people with high heart rates or arrhythmia.

    • Cardiac retrospective scanning: helical scanning of the heart over a number of cardiac cycles to allow retrospective reconstruction of the different phases, using a larger dose of radiation when compared to prospective gating. This is beneficial for people with high heart rates or arrhythmia.

Setting and intended use

The Aquilion PRIME is intended for use in secondary care settings, specifically by staff with expertise in conducting and interpreting cardiac CT imaging. Additionally, the hospital must comply with radiological protection standards, including basic standards for protection against the dangers inherent in exposure to ionising radiation. The test would be requested by a clinician involved in managing coronary artery disease, normally a cardiologist. A radiographer would carry out the scan and a radiologist or cardiologist would interpret the results.

Current NHS options

The NICE guideline on chest pain of recent onset (currently being updated) recommends CTCA for people with a low estimated likelihood (10–29%) of CAD and a calcium score of 1–400.

NICE diagnostics guidance on new generation cardiac CT scanners recommends 4 specific scanners (Aquilion ONE, Brilliance iCT, Discovery CT750 HD and Somatom Definition Flash), all of which have technical enhancements that can improve CTCA image acquisition, to be used to perform CTCA in the following groups:

  • people with chest pain who have an estimated likelihood of CAD of 10–29% and are difficult to image

  • people with known CAD in whom imaging is difficult with earlier generation CT scanners and for whom revascularisation is being considered.

NICE is aware of the following CE‑marked single‑source CT scanners that appear to fulfil a similar function to the Aquilion PRIME.

  • Aquilion ONE (Toshiba)

  • Aquilion ONE Vision (Toshiba)

  • Optima 660 (GE Healthcare)

  • Revolution GSI/HD (Discovery CT750 HD; GE Healthcare)

  • Revolution CT (GE Healthcare)

  • Brilliance iCT (first launch; Philips Healthcare)

  • iCT Elite (new generation; Philips Healthcare)

  • Ingenuity (Philips Healthcare)

  • IQon Spectral CT (Philips Healthcare)

  • Somatom Definition AS+ (Siemens)

  • Somatom Definition Edge (Siemens)

  • Somatom Definition Flash (Siemens)

  • Somatom Force (Siemens).

NICE has produced a medtech innovation briefing on the Somatom Definition Edge CT scanner. NICE has produced a technical supplement to the diagnostics guidance on new generation cardiac CT scanners to describe the newer versions of the scanners included in the guidance.

Costs and use of the technology

According to the manufacturer, the Aquilion PRIME typically costs between £350,000 and £500,000, excluding VAT, depending on the options added to the core system at the time of purchase or added any time thereafter. The lifespan of a CT scanner is 7–10 years (Clinical Imaging Board 2015). Irrespective of the capital cost, the nationally representative unit cost for a cardiac CT scan including labour time, overheads and consumables is £259 (Department of Health 2014, code RA68Z).

Training to use the Aquilion PRIME system is provided free of charge by the manufacturer.

Other diagnostic procedures used in the chest pain pathway include invasive coronary angiography (ICA), magnetic resonance imaging (MRI), single photon computed emission tomography (SPECT) and stress echocardiography (ECHO). The ICA procedure has a unit cost of £1,241 (NHS 2014/15 National tariff payment system, code EA36A). An outpatient cardiac MRI scan inclusive of contrast medium costs £527 (Department of Health 2014, code RA66Z). The unit cost for SPECT is £220 (NHS 2014/15 National tariff payment system, code RA37Z). The unit cost for stress ECHO is £74 (NHS 2014/15 National tariff payment system, code RA60Z).

CT scanner technologies need specific infrastructure and equipment, as well as suitably trained radiographic and radiological staff. There are no particular practical difficulties in using or adopting the Aquilion PRIME.

Likely place in therapy

The Aquilion PRIME would be used to perform cardiac CT imaging in adults (aged 18 years and over) with suspected CAD in whom imaging with earlier generation CT is difficult and who have an estimated likelihood of CAD of 10–29%, or known CAD in whom imaging with earlier generation CT is difficult and for whom revascularisation is being considered. The scanner may also be used to perform CTCA in people with stable angina whose symptoms are not satisfactorily controlled with medical treatment.

The Aquilion PRIME can also be used for other clinical imaging applications in adults and children.

Specialist commentator comments

One commentator stated that although CTCA is predominantly used to rule out CAD in people with an estimated likelihood of 10–29% of having the disease, it can also be used as a rule‑in test to confirm CAD in people at moderate risk (30–60%). The commentator said that, in practice, people at low, moderate and intermediate risk (10–90%) of CAD have CTCA. People at moderate risk with no sign of disease on CTCA do not have further investigations, whereas people with signs of disease are assessed further using functional imaging, the choice of which will depend on their individual circumstances. The NICE clinical guideline on the assessment and diagnosis of chest pain of recent onset recommended other forms of imaging such as SPECT, ECHO or MRI, or ICA for higher‑risk groups.

Two specialist commentators emphasised the capability of the Aquilion PRIME to scan people with obesity. One stated that the scanner has a larger bore than previous models and has the option of a bariatric table that can support a larger person. Both commentators noted that larger people need higher volumes of contrast medium or higher injection rates. One specialist commentator added that this must be balanced with the advantage of better contrast that can be obtained at lower kV levels, because lowering the kV for people with obesity can result in added image noise and affects the quality of the images. The commentator believed that the SUREkV software had the potential to automatically standardise 1 of the imaging parameters based on patient size. Another commentator noted that the automated software tends to use higher kV in people with larger body masses. One commentator did not consider that AIDR 3D iterative reconstruction could reduce the amount of contrast medium or minimise artefacts for people with obesity or grafts.

One specialist commentator stated that the Aquilion PRIME does not have specific features that address the problems posed by people with high coronary calcium.

Because of the range of available CT scanners that are capable of assessing people with bypass grafts, 1 commentator did not believe people with previous bypass grafts were difficult to image. A second commentator noted that non‑invasive imaging of the grafts is often desirable before ICA, because ICA can be challenging in this group.

One specialist commentator said that the arrhythmia detection employed by the Aquilion PRIME, including SURECardio software, is useful for people with ectopic beats (extra heartbeats) but does not address the difficulties of scanning people with atrial fibrillation. More advanced CT scanners, such as the Toshiba Aquilion ONE (which only needs a single heartbeat for image acquisition), are preferable for obtaining clear images of people with atrial fibrillation. The commentator also noted that the Aquilion PRIME does not have as high an intrinsic temporal resolution as dual‑source CT scanners or other scanners with higher tube rotation times. They noted that the retrospectively gated mode with segmented reconstruction can be used for high (regular) heart rates, but that the use of beta blockers to lower and control heart rate remains essential for best‑quality images at the lowest radiation doses, as with most coronary CT. They also noted that the optimal temporal resolution is only possible with retrospective ECG‑gating and multi‑segment reconstructions with a higher dose, increasing the possibility of movement artefacts. Finally, the commentator stated that stent visualisation is better in scanners that are more advanced than Aquilion PRIME, particularly where multiple stents may cross acquisition boundaries in prospective scanning. Another specialist commentator noted that using medication to lower heart rate has implications for people who are unable to take or tolerate beta‑blockers.

According to 1 specialist commentator, a scanner lifespan of 7 years is a long time given the rapid rate of technology evolution. The commentator also said that the nationally representative unit cost (which does not account for capital cost) underestimates the cost of advanced cardiac CT scanning in complex cases, which need more advanced (and expensive) hardware.

One specialist commentator noted that the NICE clinical guideline on the assessment and diagnosis of chest pain of recent onset was under review at the time they provided their comments, and that the NICE diagnostics guidance on new generation cardiac CT scanners is out of date because several of the models from the guidance have been superseded and are no longer available.

Two specialist commentators noted that there are currently more advanced scanners on the market that can address clinical challenges for all subgroups of people who are difficult to image. These include the Toshiba Aquilion ONE Vision, Siemens Somatom Force, Philips IQon and the GE Revolution.One of the commentators explained that Aquilion PRIME is a mid‑range scanner, similar to Siemens Definition AS+ and GE Revolution GSI/HD. The same commentator noted that dual‑source scanners have different technological solutions but are not necessarily superior to single‑source scanners for all applications. They stated that their overall impression is that the Toshiba Aquilion PRIME is an excellent general CT scanner that can produce high‑quality cardiac/coronary images, especially in people with low steady heart rates and good breath‑hold capability. It has advantages over previous generation scanners in its ability to scan people with obesity, better image quality and a significant reduction in radiation doses with the advanced iterative reconstruction. However, they added that if the purpose of buying a CT scanner is to scan people who are difficult to image (including those with arrhythmia, poor breath‑hold ability and coronary stents), it would be advisable to buy a more advanced CT scanner that significantly simplifies the scanning procedure and is more robust and 'future‑proof'. The commentator suggested that this might include those with broad detector arrays (16 cm) such as the Toshiba Aquilion ONE series or GE Revolution. This point was reiterated by another specialist commentator, who stated that, in practice, the latest CT technology would offer more image improvement and dose‑saving capability, and thus be suitable for use in everyone, including those in whom imaging is difficult.

Equality considerations

NICE is committed to promoting equality, eliminating unlawful discrimination and fostering good relations between people with particular protected characteristics and others. In producing guidance, NICE aims to comply fully with all legal obligations to:

  • promote race and disability equality and equality of opportunity between men and women

  • eliminate unlawful discrimination on grounds of race, disability, age, sex, gender reassignment, marriage and civil partnership, pregnancy and maternity (including women post‑delivery), sexual orientation, and religion or belief (these are protected characteristics under the Equality Act 2010).

People with diabetes or obesity may be considered to be disabled under the Equality Act if these conditions have a substantial and long‑term adverse effect on their ability to carry out normal day‑to‑day activities. Disability is a protected characteristic defined in the Equality Act 2010.