A Review of the Benefits and Pitfalls of Phantoms in Ultrasound-Guided Regional Anesthesia
ABSTRACT With the growth of ultrasound-guided regional anesthesia, so has the requirement for training tools to practice needle guidance skills and evaluate echogenic needles. Ethically, skills in ultrasound-guided needle placement should be gained in a phantom before performance of nerve blocks on patients in clinical practice. However, phantom technology is varied, and critical evaluation of the images is needed to understand their application to clinical use. Needle visibility depends on the echogenicity of the needle relative to the echogenicity of the tissue adjacent the needle. We demonstrate this point using images of echogenic and nonechogenic needles in 5 different phantoms at both shallow angles (20 degrees) and steep angles (45 degrees). The echogenicity of phantoms varies enormously, and this impacts on how needles are visualized. Water is anechoic, making all needles highly visible, but does not fix the needle to allow practice placement. Gelatin phantoms and Blue Phantoms provide tactile feedback but have very low background echogenicity, which greatly exaggerates needle visibility. This makes skill acquisition easier but can lead to false confidence in regard to clinical ability. Fresh-frozen cadavers retain much of the textural feel of live human tissue and are nearly as echogenic. Similar to clinical practice, this makes needles inserted at steep angles practically invisible, unless they are highly echogenic. This review describes the uses and pitfalls of phantoms that have been described or commercially produced.
Full-textDOI: · Available from: Graham Hocking, Jun 03, 2015
08/2014; 19(6):282-288. DOI:10.1080/22201173.2013.10872942
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ABSTRACT: Ultrasound-guided needle placement is a widely used technical skill that can be challenging to learn. The SonixGPS is a novel ultrasound needle-tracking system that has the potential to improve performance over traditional ultrasound systems. The objective of our study was to determine if the use of the SonixGPS ultrasound system improves performance of novice practitioners in ultrasound-guided needle placement compared with conventional ultrasound in the out-of-plane approach on a simulation model. Twenty-six medical students without previous ultrasound experience were randomized into 2 groups. Each group performed 30 simulated ultrasound nerve blocks on a porcine meat tissue simulation (phantom) model. Both groups used the SonixGPS ultrasound; however, the study group had the needle-tracking system activated, whereas the control group did not. The participants were assessed for success rate, technical aspects of block performance, and certain behaviors that could compromise the quality of the block. Learning curves were developed to assess competence. The needle guidance group reached competence more often. This group had fewer attempts and quality-compromising behaviors than did those using conventional ultrasound. Use of the SonixGPS ultrasound needle guidance system improves the performance of technical needling skills of novice trainees in an ex vivo model. The place of this technology in the wider education of ultrasound-guided regional anesthesia remains to be established.Regional Anesthesia and Pain Medicine 01/2015; DOI:10.1097/AAP.0000000000000209 · 2.12 Impact Factor
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ABSTRACT: It is commonly accepted that radiation therapy is a rapidly evolving profession with an astonishing rate of technological development. Accordingly there is much data in the literature concerning this from international studies. A Canadian study1 examined the availability of IMRT between 2006 and 2010, while regular longitudinal studies into infrastructure allow for trends in technology availability to be determined in Korea2 and Japan.3,4 There is a big difference, however, between availability of resources and actual usage with many factors affecting both referral rates5 and implementation6 of the available technology and equipment; the resource-hungry nature of commissioning frequently restricting usage.7 A 2010 UK study8 remains one of the few to investigate the link between availability and use of technology and determined that lack of personnel and funding was a common inhibitory factor. It is important to note that availability of technology was not the dominating factor in most cases. This study built on a 2012 state-wide audit9 of practice in Queensland to present data concerning national radiotherapy indications and routine technology usage. The primary rationale for the study was to inform curriculum development of academic programs in Australia and to ensure training is matched to workforce patterns of practice. The aim of the work was to gather a single representative day’s sample (“snapshot”) of radiation therapy practice across the country in order to provide an insight into patterns of practice and technology use.Journal of Medical Imaging and Radiation Oncology 08/2014; 58:204. DOI:10.1111/1754-9485.12223 · 0.95 Impact Factor