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

Abstract

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.

Appendix

Facilities and equipment

Fluoroscopy-guided interventions were performed on a digital subtraction angiography (DSA) unit (OEC 9900 Elite, GE Medical Systems, Waukesha, WI, USA). MRI-guided interventions used a 1.5 T MRI scanner (Signa HDxt, GE Medical Systems, Waukesha, WI, USA).

The experimental set-ups were all conducted on an arterial vessel phantom consisting of linked femoral, abdominal and thoracic module (L-F-S-Left-003, A-S-N-001, T-R-N-020, Elastrat, Sarl, Switzerland). The phantom was connected to a heart-lung machine (HL-30, Maquet, Rastatt, Germany), customising one HL-30 D150 pump to mimic (pulsatile) physiologic flow. Plastic tubes were taken from the phantom to the heart-lung machine, which was in an annex room. Tubes passed the Faraday cage through the wave guides. Silicon tubing (PT 12.7 $\times$ 3.2, Silex, Bordon, UK) with an inner diameter of 16 mm and length of 5 m was used. An arterial blood pressure monitoring kit with a trace was also used to examine systolic/diastolic pressures during the interventions. A permanent introducer sheath (12F) was inserted into the femoral artery to provide access and exchange of devices during the interventions. A neonatal blood pressure cuff (SoftCheck Neonatals, Statcorp Medical, Jacksonville, FL, USA) was secured to the right common iliac artery (with electrical tape and rubber sheet) to mimic stenosis (see “Appendix” in Fig. 6).

Fig. 6

Fully perfused thorax to above the knee vascular phantom (Elastrat, Sarl, Switzerland). Red arrow indicates the 12F sheath introducer used for permanent access. Blue arrow indicates a neonatal pressure cuff (SoftCheck Neonatals, Statcorp Medical, Jacksonville, FL, USA) that was attached to the right common iliac artery to mimic a stenosis

The two workstations used in the MRI, standard control console (software release 15.0M4A, GE Healthcare, Waukeska, WI, USA) and the real-time MRI software framework (RTHawk, Version 0.9.28, HeartVista, Inc., Los Altos, CA, USA) were in communication via Gigabit Ethernet and were connected via optical fibre cables (M1-1000, Opticis, Sungnam City, Korea) to a shielded 40” LCD monitor (Multeos 401, NEC Corporation, Tokyo, Japan) to display the MR images inside the MRI scanner room.

IP cameras models were: M1011w and M1031w, Axis Communications, Lund, Sweden.

Recoding spectacles were PivotHead, models Durango Chameleon and Recon Black Jet frames with no lenses fitted (Cape Evolution Ltd, Greenwood Village, CO, USA).

Second tablet device used for scanner/control room communication was an iPad 3 (Apple Inc., Cupertino, CA, USA), and the Bluetooth earphones were Calisto B70 (Plantronics, Santa Cruz, CA, USA).

Devices

We customised commercially available non-braided balloon catheters (5F PTA Balloon catheter, Workhorse II, AngioDynamics, Lathan, NY, USA) by attaching a resonant circuit 5 mm distally to the inflatable balloon. Each resonant circuit was tuned to 63.8 MHz (the proton Larmor frequency at 1.5 T) in 0.9 % saline solution.

Additional devices used during the interventions included:

• 5-F Straight catheter (BeaconTipRoyal Flush, CookInc., Bloomington, IN, USA), length 70 cm (lumen 0.035”)

• 6-F Multipurpose catheter (Soft-Vu, AngioDynamics, Latham, NY, USA), length 90 cm (lumen 0.035”)

• For fluoroscopy, commercially available 0.035” guidewires (Standard Glidewire, Terumo, Somerset, NJ, USA) were used.

• For MRI, a novel hydrophilic-coated and MRI-safe guidewire prototype that was developed with EPflex GmbH (Dettingen/Erms, Germany) was used, with a diameter of 0.035” and a length of 120 cm.

A detailed description of the fabrication of this devices can be read in Rube et al. [14].