I use ultrasound many times every single day in the ICU, but there’s a lot of unreasonable hype about this “whole body imaging” ultrasound. I’m very skeptical of the claims being made and I’ll explain why: First some fundamental limitations of US: Ultrasound doesn’t penetrate bone and doesn’t pass through air very well. This makes imaging the brain and lung parenchyma essentially impossible with US. Bowel gas also frequently makes it difficult to visualize abdominal structures like stomach, small bowel, colon. It can’t see into bone either which can limit its utility for musculoskeletal imaging. For this reason ultrasound isn’t really amenable to a “whole body scan.” It’s hard to see how this could replace other modalities (MRI, CT) if it can’t visualize so much of the body. Ultrasound exams are often dynamic. If you’ve had one you may have been asked to roll or move to visualize certain structures. This requires a skilled operator. Immersing the patient in a tank for a 1 minute scan is a cute shortcut. It’s technically easier but it probably won’t be able get optimal images, further limiting interpretation. Also are they exchanging the water in the bath each time? Much of the time spend on imaging is actually cleaning the scanner between patients. Unclear how you can quickly disinfect a liquid scanner. The theoretical resolution of ultrasound is very high, but that isn’t quite the same thing as being able to identify structures. There are lots of artifacts and limitations to ultrasound. For some organs (thyroid, kidney, liver) it’s great. For others it may be less so (pancreas, colon, stomach, etc). Hard to see this replacing existing methods, especially if the concern is cancer screening. Ultrasound isn’t really one modality. There are a lot of different techniques (B mode, M mode, 3d modes, different types of Doppler, etc). Unclear how many of these this gizmo can do. Adding these capabilities may make the scan more capable but will also add to the scan time if it has to switch modes. There’s no free lunch. There’s always a tradeoff between scan quality and time. AI is great at *certain* narrow medical image interpretation tasks. But there isn’t a massive training set of data for this “new” modality. I wouldn’t expect AI to be very good at reading these scans until they’ve accumulated millions. That means they are still paying human radiologists to interpret for the foreseeable future. Everything in medicine is based on evidence. Proving that lung cancer screening saves lives took a decade. Where are the studies for this? So far just hype. More concretely, without evidence insurance won’t pay. Finally, Who is this technique for? Yes it avoids ionizing radiation but so does MRI. Yes it’s quick, but so is a CT scan. The scan may be quick but the interpretation may be slow (It’s still dependent on human radiologists) and the machine may require time to clean. It can’t image lots of body parts so it’s hard to see how it replaces “whole body MRI scanners.” I’m sure there are tech/wellness bros who are excited but pay out of pocket for low quality wuick partial body scans but wider adoption depends on more than hype.
