Welcome back to PoCUS Previews, your illustrated guide to the world of Point of Care Ultrasound (PoCUS)!
This month’s infographic will focus on image and probe orientation, different probe movements that can be used to generate these images, and some common artifacts (or abnormal alterations in ultrasound images).
Ultrasound images can be challenging to interpret when we consider their dynamic nature and varying conventions that surround them. This infographic breaks down the orientation of an image in relation to the probe as used in the radiological convention. The differences between the radiological convention and the cardiology convention will be touched upon in future infographics.
Before we get started on breaking down various PoCUS scans, it is important to nail down the common terminology used when describing probe position and movements. For instance, if the probe is aligned parallel to the short axis of the body, the probe is said to be in transverse. Similarly, if the probe is aligned parallel to the long axis of the body, the probe is said to be in longitudinal. Each of these positions requires the probe marker (often indicated by a notch/ a green light on a transducer) to point in a certain direction as indicated in the infographic.
There are a variety of movements that can be used to generate the perfect PoCUS image. Four most common movements are described in the infographic include: Sliding, Sweeping, Rotating and Rocking. It is recommended that you try to use only one of these movements at a time to help optimize your image generation.
Finally, ultrasound images can be riddled with illusions that needs to be recognized and acknowledged for accurate image interpretation. These illusions/ alterations called “Artifacts” arise from variations in how the soundwaves travel. This infographic describes 4 common artifacts that can help you stay wary of false interpretation.
We hope that you find these series helpful the next time your preceptor calls you in to do an US scan. As always, we would love to hear any feedback from you to help improve our future infographics in the series.
Stay tuned for the next graphic in the series that gives you an overview of one of the most exciting uses of PoCUS in the ER: the FAST scan!
- Soni NJ, Arntfield R, Kory P. Point of Care Ultrasound. Elsevier Inc. 2015
Point of Care Ultrasound (POCUS) has been proven to be both clinically valuable and readily learnable. Efficient and safe use of any POCUS applicaiton involves mastery of 4 domains: knowledge of indications, image generation, image interpretation, and clinical integration. Image generation and interpretation require an understanding of how ultrasound images are generated and displayed, sonographic planes and their associated imaging conventions, and transducer technique. This summary highlights the fundamentals of POCUS physics, knobology and technique.