Brain MRI

This is a subject that I get asked about a lot by students. MRIs are tougher that CTs to read and yet can offer a lot of diagnostic assistance. I’ll be honest, 99% of the time, I rely on the neurologists or neuroradiologists to read these studies. That works for me because, honestly, we never really get these studies stat at our place. So, almost never is an MRI so important that I have to know right away what it shows. But, I’ve become convinced that that is a sort of lazy attitude. And so, I’m making an effort to learn how to better read Brain MRIs. So, you’re in luck, because as I learn, I’m going to pass that on to you. For now, what I’m passing on are a bunch of good resources.

Radiopaedia is ALWAYS a good place to start when looking for all things radiology. They have a really nice Brain MRI course that was a live event a few years back. You can register for the course still and watch the recordings, but there is a cost. For most of us who just want the basics, there is a pre-course video on YouTube that serves as a nice intro.

Rutgers neurology has another really nice video as well. This Brain Imaging Crash Course covers more than just MRI, they address MRI as well as head CT in a nice case-based format (you know I love case-based learning). It doesn’t go terribly in depth, but I suppose that’s why it’s called a crash course instead of “Everything You Need to Know About Brain Imaging.” Another good starter.

If the written word is more your speed, here are two great resources. The first is an excellent Tweetorial introduction to Brain MRI from Lee Alhilali, MD.

And finally, a great blog post from Tom Lawson called simply, “How to read a Brain MRI.” Simple and straightforward, written by a neurointensivist nurse practitioner, it covers what you need to know in neurocritical care. Incidentally, his blog “neurosciencecriticalcare” is a good site and worth bookmarking if you spend time in the neuro ICU.

There you have a few basic intro resources for reading brain MRIs. Some of you will no doubt want to go deeper, but this is a great starting place. For me, this is what I need to know right now. I’ll let you know if I decide to delve more into all the depths of MRI.

NG Tube Placement

The nasogastric tube, or NG tube, is one of the most commonly used devices in the ICU. It can be used for removing things from the stomach or adding them (in the form of medication and tube feeding). Although the small bore feeding tube (AKA Dobhoff tube) is becoming the go-to for feeding and oral med administration, even in the short term, the NG tube isn’t going anywhere. This tube is, as its name suggests, inserted into the nare and threaded down the posterior oropharynx and into the stomach. Once it is placed, you need to be sure that it’s placed correctly (you’d be amazed at the places one of these can go!)

This can often be accomplished without the use of radiography, but there are times when an X-ray is needed. The Radiologist covers when and how to use X-ray in the placement of NG tubes.

Brain Bleeds on CT

Head CTs are often mysterious to people who don’t practice neurocritical care (or related specialty). But there are some things that are not so subtle and a large hemorrhage is among them. But, there are a few different types that you should be able to differentiate between. It’s critical to be able to differentiate between a subdural hematoma and an epidural hematoma, as one is almost always a medical emergency. Through in subarachnoid hemorrhage and you’ve got three types of hemorrhage to sort out.

Medical Guidelines has a nice Instagram post to help you out.

US Guided PIV

Thanks to Lakshman Swamy for the tip for this one! US guided peripheral IV placement is a game changer. If you’re not doing this, you should. In fact, a lot of the RNs in our hospital are trained to do this now as well! It certainly saves time and pain (for us and our patients) when it comes to placing PIVs. In many cases, this can seriously reduce the need for central access and/or PICC/midline catheters.

A lot of patients can get by with PIVs, but are “hard sticks,” keep blowing IVs, or need more reliable catheters for blood draws. Using US to place these allows for selection of better, deeper veins that aren’t readily visible to the eye or amenable to palpation. And, this is 100% within the scope of practice for RNs, so train the RNs in your ICU to do this as well (note, you may have to address some hospital policies first). I’ve found when I train new ICU NPs, those with experience placing PIVs with US often pick up arterial line, PICC/midline, and central line placement much faster.

Brown EM Blog has a great post offering tips for success in US PIV placement. Additionally, 5 Minute Sono has some great videos. And finally, a nice CME article on the process is available here.

POCUS Diagnosis of Aortic Dissection

Acute Aortic Dissection is a medical emergency and often a difficult diagnosis to make. The classic presentation is tearing, mid-scapular pain, but because the aorta runs the length of the thorax and abdomen, dissection can present in various ways. I learned POCUS diagnosis of dissection as part of the RUSH exam, but that specifically looks at the abdominal aorta.

Arthur Broadstock, an EM PGY-3 at University of Cincinnati presents a great case over at Taming the SRU and looks at identifying Type A dissections with bedside POCUS. His case focuses on using the PLAX view of the heart to evaluate the aortic root. The suprasternal view of the aortic arch can also be quite useful and it’s probably the most under-taught view of the heart in terms of bedside echo.

For more on how to use that view, and lot more detail on the diagnosis of aortic dissection (Types A and B), see this nice post on POCUS 101.

Chest CT

I always have lots of students interested to learn to read radiology studies. In class, we typically only cover CXR. I occasionally do some special lectures on head CT, but it takes a lot of practice to really be able to read your own imaging studies. We don’t spend a whole lot of time in NP school teaching it. It’s something that is really better spent on the job. The fact is, with the exception of CXR, actually reading your own radiology studies is going to be highly dependent on the area in which you work.

But, I think it’s always good to be able to understand the basics. So, Dr Naveen Sharma (known on Instagram as theRadiologist) has some great posts to help. This is a really good one detailing the basic anatomy of the chest CT. Chest CT is a study that is used not infrequently in critical care, whether to evaluate for PE, look for pneumonia, or more advanced lung disease. So, check out this post with some really great teaching on the basics of reading chest CTs.

Neuroradiology for Intensivists

I have a particular bias towards neurocritical care. Even though I practice surgical critical care as well, I have an interest in neuro and I think that my practice in neurocritical care has really helped make me a better surgical intensivist as well. Neuro is a weird niche that scares lots of people who don’t do neurocritical care. So, another one of my favorite things is teaching on neurocritical care aimed specifically at non-neurointensivists.

So, I really like this video posted by Dr Casey Albin. Dr Albin is a neurointensivist who is one half of the NeuroEMCrit team and has been a guest on an upcoming episode of our Critical Care Scenarios podcast. She recently did a nice talk covering the basics of neuroimaging aimed specifically at non-neuro intensivists. She covers the basics of reading a head CT (which we’ve covered in detail before, here), CT Perfusion scans, thrombectomy scoring (TICI), how to identify liking cause of intracerebral hemorrhage, and more. I highly recommend it for anyone who wants a good overview of neuroradiology stuff.

Reading Head CTs

OK, so before I started in neurocritical care, I really didn’t know anything about reading a head CT. I’m not an expert now by any means, but I know the basics and can read an acute head CT pretty well. And, bias aside, I think this is an important skill for a critical care or emergency provider to have. Not to know all there is to know, and not to take the place of our radiology and neurology colleagues, but as a more advanced version of the CXR interpretation skill that every critical care/emergency provider needs.

Head CTs come up not all that infrequently in acute care medicine. There are the obvious examples of acute stroke or head trauma, but a non-contrast head CT is often part of the initial workup for acute mental status changes or inpatient falls. Being able to spot hemorrhages and to have an idea how bad those hemorrhages are (it’s not necessarily related to the size of the bleed) or to be able to rule in or out serious problems can be life saving.

One of my favorite sites on the Internet for all things radiology is Radiology Masterclass. A British site run by consultant radiologists, they provide excellent teaching in the essentials of radiology and offer a number of courses and tutorials. Their tutorial series on CT Brain Anatomy and Acute Brain CT are my go-to sites when I’m teaching students or new providers the fundamentals of Head CTs. They also have a number of good galleries where you can see examples of pathology and normal findings alike.

What Radiology Test Should I Order?

We order a lot of radiology tests in the ICU. But for new providers (and sometimes even those of us with experience), it can be confusing what test I really want. When you order a test, almost every system will have you list the indications, why you’re doing the test. This isn’t actually some administrator micromanaging you and making you justify every test, it helps radiology determine if this is the most appropriate test and helps the radiologist give you a more valuable interpretation.

But, what if you need some help deciding which test to order beforehand? The American College of Radiology has you covered. The ACR has a wonderful tool call the ACR Appropriateness Criteria. This tool requires you to set up a free account, but then you can search for the exam you need. It will tell you the preferred modality (X-ray, CT, MRI, US) and whether or not you need contrast. For a quick reference, the radiologists at Radia have developed this quick reference guide to help their providers decide the best study to order, and they’re good enough to make it publically available.

Barium Swallow

This is a test we order a LOT in the NSICU. It’s used to ensure that patients who have had a brain injury and an equivocal bedside swallowing exam are actually safe to swallow. They’re used a lot with another group of patients I see in the SICU a lot too, esophagectomy patients. In that case, it’s less to make sure patients aren’t aspirating and more to make sure their esophageal anastomosis isn’t leaking before they’re allowed to resume eating.

But, we often don’t see the images, just the report. So, this Instagram post from theradiologistpage is really interesting. You can see the anatomy and functional assessment involved in this study. For our Speech Language Pathologist (SLP) colleagues, this is a test they use all the time to help us determine if it’s safe for our patients to eat and what consistency/thickness of liquids are safe.