Canon Medical’s Alphenix 4D CT system enables to ease patient flow and perform liver and prostate procedures with millimetric isometric precision, a leading French interventional radiologist told VISIONS.

The interventional radiology section at Nîmes University Hospital in southern France is a leading center for the treatment of osteoarticular and soft tissue diseases. ‘Oncology represents about 70% of our activity,’ said Prof. Julien Frandon, Head of the interventional department.

The hospital installed the Alphenix 4D CT in November 2020 to anticipate to the growing need for hybrid procedures requiring a CT guided intervention combined with fluoroscopy imaging with a C-arm, for more precision and better visualization when injecting i.e embolic material and devices.

‘We really needed an all-inclusive room,’ said Prof. Frandon, who was ‘seduced’ by the equipment’s 'all in one' aspect, and, in particular, the possibility to perform image fusion.

We really liked the instant fusion possibility of vascular CT data during fluorosocopy,’ he said.

'We started performing prostate embolizations, our field of expertise, which was sub-optimal in the past due to the limitations of our conventional cone beam CT'.

With the Alphenix 4D CT, the team now works with ‘millimetric isometric precision’ in three planes. ‘We can do perfusion thanks to the wide area detector of the CT scanner, which allows us to cover 16cm in a single rotation.'

Benefits of working with a multimodal guidance system with a wide area CT detector
The Alphenix 4D CT has tremendously improved the patient flow at the hospital, Prof. Frandon explained. ‘For each patient, we used to ask ourselves: Do I need CT, X-ray or Ultrasound imaging for this procedure? Now, thanks to our multimodality interventional room, we no longer have to ask ourselves this question.’

The system enables to do virtually any type of intervention, he added. ‘We can manage our patients under CT and/or angio guidance, which is perfect. We no longer have to reschedule patients and face programming difficulties on the other radiology examination rooms. For all the complicated procedures where I’m not sure which imaging technique to use, I use the Alphenix 4D CT room.’

The team can also combine multiple imaging modalities, a possibility that is particularly relevant when carrying out liver and prostate procedures.

‘For example, when we do an arterial approach, we inject a contrast media agent directly into the superior mesenteric artery, and its venous return allows us to have a pure portal hepatic enhancement, which is called Porto-CT. This allows us to clear everything that is not hepatic parenchyma, and therefore to see even metastases that are not visible with classical contrast injections,’ he said.

The system features the Aquilion ONE wide area detector CT scanner, which was a decisive factor for his team, Frandon explained. ‘We wanted to perform liver interventions. The benefit is that, with the acquisition of 16 cm per rotation, the liver is directly visible after a single rotation, without having to make a helical CT acquisition. You have instantaneous volume acquisitions,’ he said.

This 'One shot volume scan' can be repeated over time with an exceptional temporal resolution, enabling to obtain perfusion maps, which are also useful for prostate imaging. ‘This allows us to have both perfusion imaging and 3D mapping of the vessels because, in a 16cm volume acquisition, we can visualize both the prostate and the prostatic arteries that arise from the hypogastric artery,’ he said.

Biography
Prof. Julien Frandon, an interventional radiologist, has been the head of the functional unit in the interventional section at Nîmes University Hospital, France, since November 2015.

Innovative features
Canon Medical's ^SURESubtraction application, an acquisition mode similar to a DSA sequence in angiography, brings significant advantages in daily routine, according to Prof. Frandon.

‘First, we make a mask acquisition with a very low dose, then an arterial acquisition that allows us to obtain a perfect vascular and bone CT subtraction volume automatically.’

This ability is particularly beneficial in the prostate, where traditional segmentation can be very time consuming. ‘It used to take us a lot of time, because some vessels near the sacrum were deleted on the consoles and we had to perform manual segmentation,’ he said.

‘Today, we use SURESubtraction all the time, and also in the liver. For example, we can now see if there’s new contrast enhancement of a previously treated nodule or if it’s Lipiodol from an old procedure.

’The Auto-registration module was recently installed, allowing for automatic fusion of CT volumes with fluoroscopy without the need to perform frontal and lateral fluoroscopy to align the CT volume with the actual fluoroscopy image. ‘It works very well and it’s allowed us to optimize our workflow,’ he said.

The newly designed hybrid CT touch-panel interface for CT guided interventions that enables one-handed operation was recently installed, at the team's request.

‘We're really satisfied with this upgrade. Canon Medical designed the Hybrid Touch Panel so that a single operator could perform most tasks at the bedside and fewer interactions are required from the radiographers. These are real advantages for workflow during our interventions and the optimization of our staff management.’ The Alphenix 4D CT is also equipped with Advanced intelligent Clear-IQ Engine (AiCE), a CT reconstruction algorithm based on artificial intelligence that enables to further reduce radiation dose.

‘When we do interventional procedures, we can accept a noisy image because the goal is simply to be able to guide ourselves, even at low dose,’ Prof. Frandon said. ‘Nevertheless, some operators asked for an increase in dose in order to reduce the noise. We no longer have this problem with AiCE. The image noise is removed while the texture is maintained and without distortion, allowing us to work in Ultra Low Dose.’

Patients, too, are very happy with the Alphenix 4D CT. ‘They know that the procedure will be much more precise. The fact that we have the multimodality interventional system with the wide-area CT scanner is clearly a benefit,’ he concluded.

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