1:56

But I hope to provide a more broad-based illustrative

2:01

review of the various types of pathology that

2:04

we encounter in daily practice.

2:06

So, in a top-down fashion from the face to

2:10

the skull base, to the thoracic inlet.

2:13

I'm going to start with

2:16

discussion of acute traumatic injuries and then shift to

2:19

infections. And at the end, I'm going to conclude on some

2:22

emergency cases that can be seen among the specific

2:26

population of treated head and neck cancer patients.

2:32

So, in the head and neck region,

2:34

there's a very limited role of the plain

2:37

radiograph in the emergency setting.

2:39

Though, they can be helpful in the setting of the pediatric

2:43

airway evaluation, or occasionally, for ingested

2:46

foreign bodies.

2:47

Similarly, in the ED setting,

2:50

ultrasound has a very limited role.

2:53

Because time is of the essence,

2:55

our workhorse is essentially CT with MRI reserved

2:59

for problem solving.

3:01

CT is fast, especially in the era of multi detector CT

3:05

and exams can be completed from start to finish

3:08

in the order of minutes.

3:10

They are far less prone to motion artifacts.

3:13

CT provides excellent and atomic detail with high

3:16

spatial resolution.

3:18

It allows for multiplanar, 3D, rotational

3:22

reconstructions that can really enhance our understanding

3:25

of the pathology and question.

3:28

There are always issues of radiation exposure,

3:31

but when the clinical concern is high enough,

3:34

the risk-benefit ratio often favors imaging over

3:37

withholding imaging in the urgent setting.

3:42

Contrast exposure is also less of a concern in the

3:45

ED setting and usually if contrast is needed,

3:49

we give it to make the diagnosis.

3:53

If there is an issue of a severe contrast allergies,

3:56

many institutions have

4:00

steroid, diphenhydramine prep

4:04

established, which can be completed 4 to 24 hours,

4:07

prior to imaging.

4:10

On the other hand, MRI has high soft tissue resolution.

4:14

It is better at detecting disease with respect

4:17

to tiny structures such as the meninges

4:20

and the cranial nerves.

4:21

And very often, it can provide a lot of powerful insight on

4:26

bone, soft tissue, and vascular injuries.

4:30

On the upside, there is no radiation risk

4:32

but there is the issue of time.

4:35

Not only is it time-consuming to obtain the MR images,

4:38

but there also is a time sink and assessing the

4:43

potential contraindications to scanning.

4:46

Oftentimes, in the ED setting, patients may be obtunded.

4:50

They may not be consentable,

4:52

and it will be,

4:53

it can be difficult to find relatives to clear

4:56

the patient for prostheses and devices

5:01

in order to expedite the process.

5:11

There's also the issue of metallic ballistic injury,

5:14

which may be contraindicated in the trauma setting.

5:18

A contrast in the setting of renal disease with

5:22

the concern for inciting nephrogenic

5:24

systemic fibrosis has been debated

5:27

much in the last several years.

5:28

The very recently, in the last week or so,

5:31

a recent consensus statement has been put out

5:34

by the ACR and the National Kidney Foundation,

5:37

which indicates that it is better to give a group 2

5:40

and group 3 gadolinium-based contrast agents

5:42

than withhold in most clinical situations,

5:45

even with the GFR less than 30.

5:48

So, with that said,

5:49

I consider CT to be our workhorse and MRI to be a good

5:54

problem solving technique in specific clinical scenarios,

5:57

and we'll see some examples of that moving forward.

6:01

So our role in

6:04

diagnosis is, of course,

6:05

to make the relevant findings and report

6:07

expeditiously and accurately.

6:09

But it shouldn't just be limited to that.

6:12

In the ED setting, disease processes can proceed from

6:15

bad to worse very quickly.

6:17

And it's really incumbent on us,

6:18

not just to make the findings,

6:20

but to anticipate the complications.

6:22

For example, an orbital abscess should prompt us

6:24

to look for venous thrombosis, ballistic injury in the neck

6:28

should prompt a query for vascular integrity and

6:31

appropriate imaging recommendations for that.

6:35

Once we consider those potential complications,

6:37

we need to discuss those recommendations with

6:39

the clinical service caring for the patient.

6:42

For example,

6:42

we would recommend a CT venogram exam to evaluate

6:46

for venous thrombosis in the orbital abscess setting,

6:49

or CTA neck to evaluate for vascular injury in the neck

6:52

following ballistic injury or recommend

6:55

ENT consultation for an otic capsule violating

6:58

temporal bone fracture.