Prof. Johan de Mey, M.Sc. Pieter T. Boonen, Prof. Nico Buls, Prof. Dimitri Aerden

The Alphenix 4D CT has been revolutionizing research in Interventional Radiology at the Department of Radiology, UZ Brussels University Hospital (Brussels, Belgium). Prof. Johan de Mey, the Head of Department, has selected Canon's Alphenix 4D CT to bridge the powerful image quality of CT with the versatility and flexibility of angiography. Together with his team, M.Sc. Pieter T. Boonen, Prof. Nico Buls, Prof. Dimitri Aerden, and Prof. Jef Vandemeulebroucke, he showed the benefit of using the Alphenix 4D CT to improve the evaluation of critical limb ischemia, providing valuable information on the anatomy of the blood vessels, the hemodynamic of the blood flow, and the tissue perfusion. In the future, Prof. de Mey and his department are eager to look forward and take advantage of all the clinical capabilities that this clinical system offers.

This study integrates into the peripheral arterial disease (PAD) field. PAD manifests as a circulatory problem that results in the narrowing or blockage of the peripheral arteries, reducing the blood flow to the extremities. Typically, it results in patients developing critical limb ischemia, which leads to severe consequences for patients with diabetes (e.g., diabetic food disease). This disease is usually assessed with IADSA, which provides morphological and hemodynamic information about the lesion, but it does not provide information on tissue perfusion. In addition to this, IADSA only delivers 2D information on the structures. Therefore, an image modality that allows for volume projections, like dynamic four-dimensional computed tomography (dynamic 4D CT) may be an alternative to get more details about the structures in the image. However, recent studies reported the use of high levels of the contrast agent when acquiring dynamic 4D CT images.

In this work, the researchers included data from three patients with diabetic foot disease and a high suspicion of critical limb ischemia. Between January 2021 and August 2021, these patients underwent a dynamic 4D CT examination in combination with a diagnostic IADSA in the Alphenix 4D CT room at the UZ Brussel diabetic foot clinic.

With the approach of acquiring the dynamic 4D CT images using the Alphenix 4D CT, the amount of contrast agent used was very low (2 mL) as a result of the selective intra-arterial injection for the CT acquisition. Other studies reported the intravenous injections of 40 to 80 mL of contrast agent when the patient undergoes a dynamic 4D CT examination. The use of only 2 mL of contrast agent in these procedures has a clinical benefit, especially for patients with diabetes and chronic kidney disease, since the use of a high amount of contrast increases the risk of contrast-induced nephropathy in these patients.

This technology could enhance diagnostic precision in identifying coronary artery diseases, aneurysms, and other cardiovascular conditions, leading to more informed treatment decisions. In interventional oncology, the implementation of dynamic 4D CT imaging allows for real-time imaging during minimally invasive procedures. By capturing dynamic changes in tumor vascularity and surrounding structures, clinicians could navigate interventions with increased accuracy, potentially improving the efficacy of treatments such as embolization and ablation.
Finally, in interventional radiology, Canon’s Alphenix 4D CT can be a perfect solution for Endovascular Aneurysm Repair (EVAR) procedures and its most common related complication called endoleaks. EVAR is a minimally invasive technique that is commonly conducted to repair abdominal aortic aneurysms (AAAs) using a stent-graft. This treatment has emerged as an alternative to open aneurysm repair procedures. However, EVAR can be affected by endoleaks, which are blood leaks outside the stent-graft and back into the aneurysm sac. There are different types of endoleaks, depending on the vessels that cause the inflow into the aneurysm sac. With Alphenix 4D CT, it will be possible to assess and treat this clinical complication within one room and by avoiding extra logistic actions. Moreover, using dynamic 4D CT imaging would be highly beneficial to determine the information about the hemodynamics of the blood flow to improve the endoleaks diagnosis and treatment. Next to these clear advantages, image fusion between CT image data and angiography is fast and straightforward since the patient is positioned on the same table, which means that no registration between the two imaging modalities is necessary. This three-dimensional image fusion guidance can improve the procedure time and reduce the amount of used contrast. Another strong advantage of this image fusion is the additional confidence given to the vascular surgeon and/or interventional radiologist during the procedure to improve patient outcome.

The Alphenix 4D CT is therefore shaping up to be a gamechanger in the Department of Radiology, at UZ Brussels. With their interest in integrating the Alphenix 4D CT into their clinical routine, we can foresee that the road ahead is bright, bringing improved diagnostics and better treatment for all.