The much anticipated revised guidelines for chamber quantification have been released and feature in the January publication of JASE. This is a massive undertaking and I want to start my review by acknowledging the efforts of the writing group – I can appreciate how difficult the task is! In today’s post I will aim to draw attention to some notable changes from the 2005 paper and share some of my opinions on these changes – it is not aimed to be a complete analysis of the document.
The 2005 paper is arguably the most significant echo paper published and the revised edition overall has improved significantly on this document. There has been a large growth in the amount of normal data available for the authors to base guidelines and the revised paper reflects the technological advances which have become routine clinical practice in many centres (i.e. real-time 3D and Strain). As an educator, the goal of a guideline paper is to reduce variability in how to measure and interpret findings. It represents the “go-to” document that summarises the various different techniques and papers available. This guideline revision has improved significantly on the previous guidelines, however I feel that several new challenges have arisen.
Do you blindly trust that your transducer is working? Do you know if there is any damage to the internal workings of the transducer? Would you bet your patient’s health on it?? Most of us take for granted that our equipment is functioning normally and that what we are imaging is the “truth”. A regular comment from sonographers is that the ultrasound system they are using is too old and takes poor images. If the machine is regularly serviced I would almost certainly bet the fault is with the transducer, not the machine.
It can be difficult to identify significant probe damage in a phased array transducer. We often don’t appreciate that a probe is deteriorating as there is a lot of variation in image quality between patients – we tend to attribute poor images to the patient rather than considering our equipment as a contributing factor. Today’s post highlights the need to regularly check the integrity of our transducers and proposes a basic protocol for routine transducer testing.
Happy New Year!! Let’s kick 2015 off with a reader question.
Many measurements in Echo can be made from multiple locations (PLAX vs PSAX; A5C vs ALAX). Experienced sonographers will have a “favorite” way of imaging which is passed down to the next generation of trainee sonographers as the “correct” way, although we often do a poor job of verbalizing “Why” we measure one way over the other. Theories are thrown around, some hilarious, some reasonably valid…but at the end of the day all the techniques are probably just as good as each other; we just need to be aware of the pitfalls. The published guidelines suggest that for some measurements we can use either axis, however as an Echo.Guru reader pointed out recently, the measurements may be different between the two views… so which axis is best to measure from??
The apical long axis (ALAX) can be a difficult view to master for many sonographers. A quality, on-axis image is obtained when the image transects the true apex and also needs to pass through the center of the mitral valve (commonly the middle scallops: P2 and A2). The aortic valve leaflets should also be seen to be opening well and the ascending aorta is opened out. It can sometimes be challenging to achieve all these aspects in the one image. Here are some tips for imaging this view on-axis every time!
In an earlier post we looked at how to obtain the perfect on-axis image. I focused on the golden rule of “tilt for the centre and rotate for the sides”. But what happens if we aren’t in the right intercostal space to start with?!?!? Today’s post looks at how you can identify the correct intercostal space for imaging the parasternal long axis view (PLAX).
Angle for the center, rotate for the sides (and always in that order).
Aliasing phenomenon is a concept that causes a lot of uncertainty for many of us. We all have a rough idea of what it is, until we have to explain it to a trainee sonographer doing their best impression of a 3 year old [insert annoying voice here] “… But why???”.
This week’s post was requested by Bec from South Australia. Thanks for jumping straight in with the tricky stuff!
I am often asked, “How long should an echo take??”.
Trainee sonographers want to know if they are on track, overworked sonographers often ask before approaching management to address workplace issues, practice managers are interested in the answer to aid with rostering and timetabling. I am interested in the answer as I campaign for improved quality of our scans. Patients are interested in the answer to know how long they are going to be stuck in our room…. There seems to be an endless number of reasons for asking the question, and unfortunately the answer upsets more people than it pleases.