Comparative ergonomic workflow and user experience analysis of MRI versus fluoroscopy-guided vascular interventions:an iliac angioplasty exemplar case study

Purpose A methodological framework is introduced to assess and compare a conventional fluoroscopy protocol for peripheral angioplasty with a new magnetic resonant imaging (MRI)-guided protocol. Different scenarios were considered during interventions on a perfused arterial phantom with regard to time-based and cognitive task analysis, user experience and ergonomics. Methods Three clinicians with different expertise performed a total of 43 simulated common iliac angioplasties (9 fluoroscopic, 34 MRI-guided) in two blocks of sessions. Six different configurations for MRI guidance were tested in the first block. Four of them were evaluated in the second block and compared to the fluoroscopy protocol. Relevant stages’ durations were collected, and interventions were audio-visually recorded from different perspectives. A cued retrospective protocol analysis (CRPA) was undertaken, including personal interviews. In addition, ergonomic constraints in the MRI suite were evaluated. Results Significant differences were found when comparing the performance between MRI configurations versus fluoroscopy. Two configurations [with times of 8.56 (0.64) and 9.48 (1.13) min] led to reduce procedure time for MRI guidance, comparable to fluoroscopy [8.49 (0.75) min]. The CRPA pointed out the main influential factors for clinical procedure performance. The ergonomic analysis quantified musculoskeletal risks for interventional radiologists when utilising MRI. Several alternatives were suggested to prevent potential low-back injuries. Conclusions This work presents a step towards the implementation of efficient operational protocols for MRI-guided procedures based on an integral and multidisciplinary framework, applicable to the assessment of current vascular protocols. The use of first-user perspective raises the possibility of establishing new forms of clinical training and education

Effect of the hybrid composition on the physicochemical properties and morphology of iron oxide-gold nanoparticles

Hybrid nanoparticles (HNPs) formed from iron oxide cores and gold nano-shells are becoming increasingly applicable in biomedicine. However, little investigation has been carried out on the effects of the constituent components on their physical characteristics. Here we determine the effect of polymer intermediate, gold nano-shell thickness and magnetic iron oxide core diameter on the morphological and physical properties of these nano-hybrids. Our findings suggest that the use of polymer intermediate directly impacts the morphology of the nanostructure formed. Here, we observed the formation of nano-sphere and nano-star structures by varying the cationic polymer intermediate. The nano-stars formed have a larger magnetic coercivity, T 2 relaxivity and exhibited a unique characteristic nano-heating pattern upon laser irradiation. Increasing the iron oxide core diameter resulted in a greater T 2 relaxivity enhanced and nano-heating capabilities due to increased surface area. Increasing the gold nano-shell thickness resulted in a decreased efficiency as a nano-heater along with a decrease in T 2 relaxivity. These results highlight the importance of identifying the key traits required when fabricating HNPs in order to tailor them to specific applications

Hybrid gold-iron oxide nanoparticles as a multifunctional platform for biomedical application

<p>Abstract</p> <p>Background</p> <p>Iron oxide nanoparticles (IONPs) have increasing applications in biomedicine, however fears over long term stability of polymer coated particles have arisen. Gold coating IONPs results in particles of increased stability and robustness. The unique properties of both the iron oxide (magnetic) and gold (surface plasmon resonance) result in a multimodal platform for use as MRI contrast agents and as a nano-heater.</p> <p>Results</p> <p>Here we synthesize IONPs of core diameter 30 nm and gold coat using the seeding method with a poly(ethylenimine) intermediate layer. The final particles were coated in poly(ethylene glycol) to ensure biocompatibility and increase retention times <it>in vivo</it>. The particle coating was monitored using FTIR, PCS, UV–vis absorption, TEM, and EDX. The particles appeared to have little cytotoxic effect when incubated with A375M cells. The resultant hybrid nanoparticles (HNPs) possessed a maximal absorbance at 600 nm. After laser irradiation in agar phantom a ΔT of 32°C was achieved after only 90 s exposure (50 μgmL^-1). The HNPs appeared to decrease T₂ values in line with previously clinically used MRI contrast agent Feridex®.</p> <p>Conclusions</p> <p>The data highlights the potential of these HNPs as dual function MRI contrast agents and nano-heaters for therapies such as cellular hyperthermia or thermo-responsive drug delivery.</p