Transcatheter Aortic Valve Implantation (TAVI) Planning with Dual-Layer Spectral CT Using Virtual Monoenergetic Image (VMI) Reconstructions and 20 mL of Contrast Media.

Transcatheter aortic valve implantation (TAVI) is a less invasive alternative to surgical implantation and its implementation is progressively increasing worldwide. We routinely perform pre-procedural aortic angiography CT to assess aortic dimensions and vascular anatomy. This study aims to evaluate the image quality of CTA for TAVI planning using dual-layer spectral CT, with virtual monoenergetic image reconstructions at 40 keV. Thirty-one patients underwent a CTA protocol with the injection of 20 mL of contrast media. Image quality was assessed by measuring the mean density in Hounsfield Units (HU), the signal-to-noise ratio, and the contrast-to-noise ratio in VMI reconstructions. Additionally, a blinded subjective analysis was conducted by two observers. The results showed significant enhancement at all sampled vascular levels with a gradual decrease in HU from proximal to distal regions. Favourable subjective ratings were given for all parameters, with greater variability in the evaluation of iliac axes. A significant negative correlation (p < 0.05) was observed between BMI and CA at all vascular levels, indicating reduced contrast enhancement with increasing BMI. Spectral CT, along with reducing iodine load, allows for obtaining high-quality images without a significant increase in noise. The reduction in iodine load can have positive implications in clinical practice, improving patient safety and resource efficiency.

Simulator training reduces radiation exposure and improves trainees' performance in placing electrophysiologic catheters during patient-based procedures.

BACKGROUND: Currently, training in interventional electrophysiology is based on conventional methodologies, and a paucity of data on the usefulness of simulation in this field is available. OBJECTIVE: The purpose of this study was to evaluate the impact of simulator training on trainees' performance in electrophysiologic catheter placement during the early phase of their learning curve. METHODS: Inexperienced electrophysiology fellows were considered. A hybrid high-fidelity simulator (Procedicus VIST, version 7.0, Mentice AB Gothenburg, Sweden for Biosense Webster) was used. The following parameters were evaluated in 3 consecutive patient-based procedures before and after two training sessions of at least 1.5 hours on the simulator: (1) ability to place catheters in conventional recording/pacing sites (coronary sinus, His-bundle area, high right atrium, and right ventricular apex); (2) amount of help provided by the supervisor (scale from 1-3; 3 for maximal help); (3) fluoroscopy time; and (4) positioning time. RESULTS: Seven fellows performed 168 catheter placements during 42 patient-based procedures with no complications. Comparing parameters before and after simulator training, there was a significant reduction in the mean amount of help and in fluoroscopy and positioning times per placement: from 1.71 ± 1.24 to 0.42 ± 0.68 (P <.001), from 121 ± 88 seconds to 76 ± 54 seconds (P <.001), and from 175 ± 138 seconds to 102 ± 74 seconds (P <.001), respectively. Overall fluoroscopy time per patient decreased from 567 ± 220 seconds to 305 ± 111 seconds (P <.0001). Improvement appeared to be related to simulator training alone and not to the previously performed patient-based procedures. CONCLUSION: During the early phase of the trainees' learning curve, simulator training significantly improves the independent trainees' performance with reduction in radiation exposure.