Introduction to Vascular Imaging of the Head and Neck

This lecture is the first part of a capstone course we have for our 4th year medical students about how to approach vascular imaging of the head and neck, including angiography, CT angiography, MR angiography, and ultrasound. To see more about this course, check out the full vascular capstone page. It contains interactive cases that you can scroll on your own as well as some additional videos explaining them.

In this lecture, we have a special guest, Dr. Cynthia Wu, who is going to explain to us some of the general concepts behind vascular imaging of the head and neck, different techniques you can do to perform vascular imaging, and when you might order each type of study.

Basic concepts

In general, to see vessels better on imaging, we need to use some sort of contrast to differentiate the vessels from the surrounding tissues. For techniques like CT, we can use an injected contrast agent to see the vessels. For other techniques such as MR angiography and ultrasound, we can use intrinsic properties of flowing blood to emphasize the vessels.

This section covers the key concepts behind how we see the vessels for these major techniques.

When do I order these tests?

Once you know about the different possible techniques, then you have to figure out when you would possibly order them. Each technique (CTA, MRA, and US) have different advantages and disadvantages that make them more or less suited to different scenarios.

What’s next?

Once you’ve finished this video, I recommend moving on to the next section of the vascular capstone, where you can learn a general strategy for interpreting a CT angiogram of the head and neck.

The capstone overview is here, if you’d like to see all the browseable cases and videos.

Or, see all of the vascular capstone videos in the vascular imaging capstone playlist.

How to read a CT angiogram (CTA) of the Head and Neck

With increasing ability to image vascular phenomena, such as stroke and vascular malformations, through the use of very efficient and high speed computed tomography scanner (CT), we now have the ability to perform angiographic imaging of large segments of the body at one time. This has led to an explosion of vascular imaging of the head and neck to look for a variety of pathologies, including stroke, vascular malformations, and other vascular abnormalities. Every starting radiology resident needs a firm foundation in how to interpret these images.

Overview

Because there are a ton of images and a ton of structures that you need to look at, you really need a regimented approach, or search pattern, to use as you look through the images. In this video, I teach you how to look at a CT angiogram of the head and neck from start to finish so you can learn how to do it yourself. There are interactive examples that you can follow along on the vascular capstone page.

In this video, we go through a normal example.

I divide the study into the CTA of the neck, which I review first, and the CTA of the head, which I review second. My pattern goes as follows:

Nonvascular structures

I first like to look at all the nonvascular structures to make sure I’m not missing anything. I look at the lungs, the thyroid, the soft tissues of the neck (particularly to look for lymph nodes or mucosal masses), and the brain. I use a soft tissue window to look at these. Then I go back through with a bone window to look at the bones.

Neck Vessels

For the vessels of the neck, I use an approach that first does anterior vessels and then posterior vessels, moving from right to left. I follow the right common carotid artery through the bifurcation, and then follow the internal carotid to the skull base. I then repeat this pattern for the left carotid system. Then, I start from the right vertebral origin and follow it up to the skull base. Then the left vertebral artery. Once I’m finished, I restart at the skull base.

Head Vessels

For the vessels of the head, I follow a similar approach. I first follow the right ICA through the carotid terminus and then follow the right middle cerebral artery (MCA) and anterior cerebral artery(ACA). Once finished, I return to the skull base and repeat this pattern on the left. I then move to the posterior circulation, where I first follow the right vertebral artery, the basilar artery, and the right posterior cerebral artery (PCA). Then I repeat it on the left. My final search is to quickly look at the deep venous sinuses.

Summary

While others may have a different strategy, the most important part is to have a strategy and stick to it. This pattern of dividing the study into discrete sections will help you see all the findings and describe them accurately when reading cases on your own.

See all of the search pattern videos on the Search Pattern Playlist.

Brain MRI – Seizure search pattern

Many times when patients have a history of seizures, they undergo a workup including a physical exam, detailed EEG analysis, and finally brain MRI to try to identify any potential structural causes of seizures. In this video, Dr. Michael Hoch walks us through his approach to a brain MRI to maximize your sensitivity for finding abnormalities.

 

Dr. Hoch suggests a 4-step approach using the mnemonic “3-2-1 go to the hippocampus”. In this way, he divides his search into more digestible parts.

“3” indicates the 3 planes that you have in a non-contrast T1 weighted MP-RAGE MRI. On this you should focus on the cortex, particularly at the 3 poles, the frontal, temporal, and occipital poles.

“2” indicates the 2 planes of FLAIR and 2 window settings you should use. You should review FLAIR images in both the coronal and axial planes. You should also use a window that is normal and a window that is narrow, or aggressive, to highlight lesions, particularly in the cortex, which are hard to see.

“1” indicates the single plane of blood sensitive imaging, either GRE or SWI, which can often see areas of prior hemorrhage or cavernou

“Go” to the hippocampus last to look for signs of mesial temporal sclerosis, which is manifested as a small hippocampus with loss of internal architecture and abnormal T2/FLAIR hyperintensity. This can be either from primary epilepsy or secondary to another lesion.

See this and other videos on our Youtube channel .

Board Review 3 – Full lecture

This lecture is a board review lecture geared towards preparation for the radiology resident ABR core exam, although similar material is used for the ABR certifying exam general and neuroradiology sections.

The format of this lecture is case-based. Each case consists of a series of images followed by 1 or 2 questions. The first question is usually to name the diagnosis, while the second is a multiple choice question to test deeper understanding of the specific condition. Try to get the diagnosis before you see the second questions.

The first 10 cases cover brain tumors and the remaining 9 cover general neuroradiology. The final case will be a high speed multiple choice review.

Noncontrast MRI cervical spine search pattern

Magnetic resonance imaging (MRI) of the cervical spine is a very commonly encountered test which can be performed for a variety of indications, including degenerative disease, trauma, demyelinating disease, and metastatic disease. Most of these cases will be done without contrast, as most of the information is there on a non-contrast exam.

This video will walk you through a step-by-step approach to evaluating an MRI of the cervical spine. The optimal approach is to use select sequences to evaluate each part of the study in the following order:

Alignment
Vertebral bodies
Marrow signal
Intervertebral discs
Spinal cord/canal
Soft tissues
Individual levels

Each sequence in the study has strengths at looking at one or more of these things. As we walk through, we’ll take a look at how to use each one.

The level of this lecture is appropriate for medical students, junior residents, and trainees in other specialties who have an interest in neuroradiology or may see patients with spine diseases.

See this and other videos on our Youtube channel.

CT (computed tomography) face radiology search pattern

When you start taking call as a radiology resident, a common test you are going to encounter is a maxillofacial CT, or face CT. This is especially true if you are taking call at a level 1 or level 2 trauma center. A lot of times, this is done in conjunction with a head and/or cervical spine CT. This is an extremely common test in the setting of trauma, including assault and car accidents (MVA or MVC). The key in these settings is to rule out a significant fracture or soft tissue injury to the face.

Because there are a lot of structures, it is important to have a useful search pattern. Reconstructions, especially the coronal reconstruction, are key when interpreting CT of the face. These allow you to see key structures that are parallel to the slice plane on axial images. Symmetry is extremely helpful, as the left should match the right. Additionally, making sure all the fat and fascia planes are clean is very useful.

This video will walk you through a step-by-step approach to evaluating a CT of the face. I recommend a pattern where you start with the coronals at the cranial (top) part of the image, and then work your way down. In this way, you can look at the brain, orbits, sinuses, palate, mandible, and so forth, minimizing the risk of missing a significant finding. Then you can repeat the pattern with the axial images. Finally, the sagittal images are a nice troubleshooting tool, especially for the mandible and cervical spine. As you practice, you will find you can move more quickly through your search without necessarily focusing on each individual element for too long.

The level of this lecture is appropriate for medical students, junior residents, and trainees in other specialties who have an interest in neuroradiology or may be involved with patients with facial injuries and other abnormalities.

 

See this and other videos on our Youtube channel.

Board Review 2 – Full lecture

This lecture is a board review lecture geared towards preparation for the radiology resident ABR core exam, although similar material is used for the ABR certifying exam general and neuroradiology sections.

The format of this lecture is case-based. Each case consists of a series of images followed by 1 or 2 questions. The first question is usually to name the diagnosis, while the second is a multiple choice question to test deeper understanding of the specific condition. Try to get the diagnosis before you see the second questions.

These are all general neuroradiology questions.

Board Review 2 – Introduction

Neuroradiology board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.

This video is a brief introduction before beginning the case style review.

Introduction to Neuroradiology Board Review: Part 2

Neuroradiology search patterns

As radiologists, we often forget that we didn’t know how to go through a study from the beginning. This playlist will be a collection of videos on how to approach studies from scratch. This may be particularly useful to beginning medical students and residents who haven’t sat down at the PACS and looked through a study many times.

Be sure to check back often as more videos are added that cover your favorite neuroradiology exams, or check out our full channel on Youtube.