A multimodality vascular imaging phantom of an abdominal aortic aneurysm with a visible thrombus. Issue 6 (14th May 2013)

• Record Type: Journal Article
• Authors: Allard, Louise; Soulez, Gilles; Chayer, Boris; Qin, Zhao; Roy, David; Cloutier, Guy
• Is Part Of: Medical physics. Volume 40:Issue 6(2013)Part 1
• Page Start: n/a
• Page End: n/a
• Publication Date: 2013-05-14
• Subjects: Computed tomography -- Radiography -- Biomechanics -- Magnetic resonance imaging -- Mechanical and electrical properties of tissues and organs; biomechanics -- biomedical MRI -- biomedical ultrasonics -- blood vessels -- computerised tomography -- diagnostic radiography -- diseases -- image sequences -- lung -- medical image processing -- phantoms -- stents -- surgery -- viscoelasticity -- X‐ray absorption; vascular flow phantom -- abdominal aortic aneurysm -- thrombus -- medical imaging -- medical physics; Involving electronic [emr] or nuclear [nmr] magnetic resonance, e.g. magnetic resonance imaging -- Computerised tomographs -- Diagnosis using ultrasonic, sonic or infrasonic waves -- Surgical instruments, devices or methods, e.g. tourniquets -- Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents -- Digital computing or data processing equipment or methods, specially adapted for specific applications -- Image data processing or generation, in general; Medical imaging -- Gels -- Ultrasonography -- Tissues -- Medical image noise -- Digital subtraction angiography -- Computed tomography -- Vascular system -- Anatomy -- Mechanical properties; Medical physics -- Periodicals; Medical physics; Geneeskunde; Natuurkunde; Toepassingen; Biophysics; Periodicals; Periodicals; Electronic journals; 610.153
• DOI: 10.1118/1.4803497
• Languages: English
• ISSNs: 0094-2405

Abstract

Abstract : Purpose: With the continuous development of new stent grafts and implantation techniques, it has now become technically feasible to treat abdominal aortic aneurysms (AAA) with challenging anatomy using endovascular repair with standard, fenestrated, or branched stent‐grafts. In vitro experimentations are very useful to improve stent‐graft design and conformability or imaging guidance for stent‐graft delivery or follow‐up. Vascular replicas also help to better understand the limitation of endovascular approaches in challenging anatomy and possibly improve surgical planning or training by practicing high risk clinical procedures in the laboratory to improve outcomes in the operating room. Most AAA phantoms available have a very basic anatomy, which is not representative of the clinical reality. This paper presents a method of fabrication of a realistic AAA phantom with a visible thrombus, as well as some mechanical properties characterizing such phantom. Methods: A realistic AAA geometry replica of a real patient anatomy taken from a multidetector computed tomography (CT) scan was manufactured. To demonstrate the multimodality imaging capability of this new phantom with a thrombus visible in magnetic resonance (MR) angiography, CT angiography (CTA), digital subtraction angiography (DSA), and ultrasound, image acquisitions with all these modalities were performed by using standard clinical protocols. Potential use of this phantom for stent deployment was also tested. A rheometer allowed defining hyperelastic and viscoelastic properties of phantom materials. Results: MR imaging measurements of SNR and CNR values on T1 and T2‐weighted sequences and MR angiography indicated reasonable agreement with published values of AAA thrombus and abdominal components in vivo . X‐ray absorption also lay within normal ranges of AAA patients and was representative of findings observed on CTA, fluoroscopy, and DSA. Ultrasound propagation speeds for developed materials were also in concordance with the literature for vascular and abdominal tissues. Conclusions: The mimicked abdominal tissues, AAA wall, and surrounding thrombus were developed to match imaging features of in vivo MR, CT, and ultrasound examinations. This phantom should be of value for image calibration, segmentation, and testing of endovascular devices for AAA endovascular repair.