Fusion imaging and virtual navigation devices among the “most important and relevant” advancements

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Luigi_A_Solbiati_mainWe are organising the first World Meeting on Fusion Imaging and Augmented Reality for Interventional Procedures within the well-known Interventional Radiology Sans Frontiéres( IOSF) Congress (7–9 July, Milan), write Luigi A Solbiati and Giovanni Mauri.

 

Thermal ablation is increasingly being used for the local treatment of several different types of tumours in different body regions. An essential prerequisite for the success of percutaneous image-guided ablations is the availability of reliable imaging techniques for pre-procedural planning, intra-procedural targeting and monitoring, and post-procedure assessment of the results achieved. In order to improve image-guidance and to overcome the limitations of using a single imaging modality, systems that are able to fuse, in real-time, image datasets produced by different imaging modalities such as ultrasound (US) fused with CT or MRI or even PET have been developed over the last few years and successfully applied to interventional oncology procedures. This allows the precise targeting of even focal lesions undetectable or inconspicuously detectable with US.

Image fusion systems were introduced into clinical practice in 2002 at the Hospital of Busto Arsizio, Italy, and at the National Institutes of Health in Bethesda, USA, and are nowadays extensively used worldwide. They are highly automated and chea and are being installed and employed directly in the ultrasound interventional room.

In the more than 2,000 (mostly hepatic) malignant tumours targeted with fusion imaging and ablated with radiofrequency, microwaves or laser ablation in our centres (General Hospital of Busto Arsizio and, more recently, Humanitas University and Research Hospital in Milan, Italy), we see extremely interesting results in cases of “challenging” treatments, such as with tumours completely undetectable on US. These are targeted using the “virtual needle” provided by the fusion system. Precise targeting occurs in as many as 91.7%  for small hepatic malignant lesions, cervical malignant adenopathies and parathyroid tumours visualised only on PET-CT, and detected and targeted in the US room, fusing US with PET-CT.

Several studies for further technical improvement of fusion imaging systems are currently being performed, and many advancements will be available in the next three years. A new generation of wireless miniaturised electromagnetic sensors with bluetooth technology will enable the use of needles and ablation devices with trackable tips. These will be precisely controllable in all the phases of interventional procedures, even in case of needle bending. Coupled with radiofrequency identification (RFID) technology, these sensors will allow the use of several different devices simultaneously, without the physical limitation of multiple wires, and will even be implantable for future controls of targeted lesions. Further advancements will be the development of sensors for physiological monitoring of respiratory phases and ECG, enabling the improvement of correlation between patients and their image datasets during either respiratory or cardiac phases.  These will then be integratied into image fusion systems aimed at increasing the detectability of pathologic targets in various organs, such as breast, prostate, lung and more.

The increasing use of matrix US probes and the development of new processors and new graphics cards will allow us to generate US imaging with extremely high frame rate to employ Doppler techniques and/or dedicated image processing to significantly improve the coregistration of image datasets with patients. Such techniques, combined with the development of deformable or elastic registration, will enable the use of image fusion for all organs.

Last but not least, the application of augmented reality to interventional procedures, with specifically designed devices, such as glasses enabling the visualisation of pre-acquired volumetric images of patients together with the virtual image of ablation devices will completely change the appearance of the interventional suite of the future: there will be no more large monitors or big machines, but only wireless devices and radiologists with strange glasses routinely working in a virtual environment.

Since fusion imaging and virtual navigation devices are considered among the most important and relevant advancements in the world of interventional radiology, we are organising the first World Meeting on Fusion Imaging and Augmented Reality for Interventional Procedures within the well-known Interventional Radiology Sans Frontiéres( IOSF) Congress (7–9 July, Milan). Speakers from all over the world will present on the most recent technological advancements in these fields, demonstrate the most relevant clinical applications already available, and highlight future perspectives.


Luigi Solbiati is with the Department of Biomedical Sciences, Humanitas University and Department of Radiology, Humanitas Research Hospital-Rozzano, Milan, Italy.Giovanni Mauri is with the Department of Radiology, European Institute of Oncology, Milan, Italy.