Siemens Acuson P500 Vet Review

In my search for a new veterinary echocardiography machine, I tried both the Siemens Juniper and the P500, before settling on the P500. As tempted as I was by the Juniper’s unparalleled image quality, I had to be sensible and keep in mind practical considerations – namely, that I need something that I can easily move around.

The Acuson P500 seemed to be able to deliver portability without compromising image quality or functionality, as is often the case with portable ultrasound systems, but with the microconvex probe not yet launched, my purchase was an act of blind faith: I had only seen the phased array probes in use before.

My first echocardiography clinic with the P500

The first few days on any new ultrasound machine are always uncomfortable at best, terrifying at worst. I am very experienced at figuring out different makes and model of ultrasound machine and this doesn’t phase me at all, but there’s a big difference between figuring your way around a new machine on a superficial level (for example, to check out its image quality or to help somebody with their scanning), and incorporating an unfamiliar system into your daily routine and scanning protocol.

The first quirk I ran into on the P500 was that pressing ‘freeze’ and then ‘save cine’ results in the machine saving every single frame since your last freeze. I haven’t checked to see what the time limit on this is set to in my config, but it seems to be very long – in the order of minutes. When one saves this way not only does it play the whole loop back as it saves, but it does so at half speed, so saving a 60 second clip means staring at the screen for 2 minutes, trying to make jokes to preserve the goodwill of the assisting vet nurse, though the patient’s ever-fading tolerance is another story. I am so used to freezing my image before deciding to save the clip that I did not think not to do this, and it took a phone call to my supplier for help (which, I have to say, was immediate) to know that I could simply press ‘save cine’ without freezing and it would save just a 3 second clip, without interrupting my scanning at all.

After my first echo clinic on the P500 was over, I was definitely wondering if I’d made a mistake. All of my images seemed to have rib artefact over them, which I never had a problem with on my previous system, and my feline echocardiograms were so fuzzy that I worried about their diagnostic accuracy. However, given that most of this scanning session had been devoted to figuring out how to save video clips correctly, I knew that I needed to persevere.

On a positive note, one thing I really was loving already about my new machine was the ‘anonymise’ option when exporting my studies, which removed the patient name and ID from the top of my scans for me – ideal for data security and also meaning I had images on hand for sharing and teaching that I did not need to worry about anonymising.

Finding my comfort zone

In between my first and second echo clinics, I had a few basic abdominal scans booked in, which gave me a chance to test-drive the new microconvex probe in a less time-pressured environment. I had managed to use it once during my echo clinic on a dog with ascites, but this wasn’t much of a test. I was now confident in saving clips properly, at least, so I could devote more of my energies to optimising my images. At first, I felt the same disappointment at the images I was obtaining, but soon realised that tissue harmonic imaging (THI) on the P500 makes a huge difference to image quality. The default on my machine seems to be to have THI on when using the phased array probe (classic cardiology default), and off when using the microconvex probe, but so far I have been finding that turning THI on for small animal abdominal scanning massively improves my picture – but turning it off for cardiac scanning in very small patients (e.g. very slim cats), conversely, greatly improves image quality.

Now that I was getting better B-mode images on my machine, I turned my attention to optimising my colour Doppler images. There are a lot of different colour maps available on the Acuson P500, and I am still making my mind up on my favourite. 3 examples are shown below in a dog with mitral valve disease. The middle colour map shows variance (in green):

The thing I love about the colour Doppler on this machine is definitely it sensitivity. Ultrasound machines with inadequate colour Doppler for small animal echocardiography – but sold to vets, incorrectly advertised as suitable for this very purpose – are of huge irritation to me, so my default position when looking at any new echo machine is one of suspicion and scepticism. The P500 quickly proved itself more than capable, and in fact, very soon surpassed my expectations as I realised that the high sensitivity of its colour Doppler meant that I was noticing things I had not previously picked up on. Ok, I’m talking things of no real clinical importance – trace aortic regurgitation or trivial pulmonary regurgitation – but even so, having that level of precision in your colour Doppler is very reassuring.

Exceeding expectations

I am now in my third week with my new P500, and it has well and truly exceeded my expectations. It has abilities which improve my performance as an echocardiographer, such as the superior colour Doppler performance mentioned above, and it has time-saving features that simply improve my day (such as the anonymisation feature). Coming from a ‘big name’ brand like Siemens, it is also automatically compatible with mainstream DICOM readers and reporting software.

My previous reporting method involved exporting images to USB, flicking through them on my computer, and then running back to my ultrasound machine to repeat any measurements I felt unsure about before exporting them back onto USB again. Now, I simply walk in the door, connect my P500 to the router with a network cable, and upload my studies in DICOM format to a server where I can perform measurements from my own computer.

I still have a lot to learn about my new machine. I haven’t even begun to play with grey scale maps yet – the Siemens image definitely needs adapting to, versus the higher contrast echo images I am used to seeing, and I know the veterinarian I scan with definitely prefers a more ‘black and white’ image. I know that I can adjust the machine to give this more ‘traditional’ echo image appearance, and my next step is to create pre-sets for both me and her, so that we are always scanning with the type of image we are happiest with. The reason I have resisted doing this so far is I do believe it takes having a few (>20) scans under your belt with a new machine before you can really judge what you like and don’t like, because anything you see on a new machine is going to feel uncomfortable when you first begin using it.

Summary

The Siemens Acuson P500 is a highly professional portable ultrasound machine that, with the launch of the new microconvex probe, is ideal for small animal use. It definitely holds its own against high end systems from the other big brands, yet is more affordable, and better supported.