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Training Collections
Library Memberships
On-demand course library with video lectures, expert case reviews, and more
Fellowship Certificate™ Programs
Practice-focused training programs designed to help you gain experience in a specific subspecialty area.
Ultimate Learning Pass
Unlock access to our full Course Library and all self-paced Fellowships.
Continuing Medical Education (State CME)
Complete all of your state CME requirements in one convenient place.
Noon Conference (Free)
Get access to free live lectures, every week, from top radiologists.
Case of the Week (Free)
Get a free weekly case delivered right to your inbox.
Case Crunch: Rapid Case Review (Free)
Register for free live board reviews.
Dr. Resnick's MSK Conference
Learn directly from the MSK Master himself.
Lower Extremities MRI Conference
Musculoskeletal Imaging
Emergency Imaging
PET Imaging
Pediatric Imaging
For Training Programs
Supplement your training program with case-based learning for residents, registrars, fellows, and more.
For Private Practices
Upskill in high growth, advanced imaging areas.
Compliance
NewTrack, fulfill, and report on all your radiologists' credentialing and licensing requirements.
Emergency Call Prep
Prepare trainees to be on call for the emergency department with this specialized training series.
4 topics, 10 min.
10 topics, 19 min.
17 topics, 1 hr. 11 min.
Anterior Globe Rupture with Laterally Dislocated Cataract
4 m.Foreign Body in Globe
4 m.Wood Foreign Body and Ocular Hypotony
2 m.Hemmorhage in Both Chambers, Open Globe
3 m.Staphyloma
4 m.Persistent Hyperplastic Primary Vitreous (PHPV)
5 m.Retinal Detachment
3 m.Retinoblastoma on CT
4 m.Retinoblastoma on MRI
9 m.Bilateral Retinoblastoma
7 m.Ocular Pathology - Review
11 m.Endophthalmitis
3 m.PHPV Review, Coloboma, and Staphyloma
5 m.Phthisis Bulbi, Macrophthalmia, and Microphthalmia
4 m.Ocular Calcification
4 m.Retinoblastoma - Review
5 m.Choroidal Melanoma
3 m.15 topics, 1 hr. 8 min.
Intraconal, Conal and Extraconal Anatomy
1 m.Intraconal Hemangioma
5 m.Venous Vascular Malformation
3 m.Optic Nerve Glioma, NF1
4 m.Optic pathway glioma (pilocytic astrocytoma)
4 m.Optic Neuritis, Multiple Sclerosis
6 m.Optic Neuritis, Multiple Sclerosis (2)
7 m.Neuromyelitis Optica Spectrum Disorder
5 m.Neuromyelitis Optica With Spinal Cord Involvement
3 m.Optic Nerve Sheath Meningioma
5 m.Bilateral Optic Neuritis, Leukemia
6 m.Intraconal Pathology - Review
11 m.Optic Neuritis - Review
5 m.Optic Nerve Glioma - Review
4 m.Optic Nerve Sheath Meningioma - Review
6 m.5 topics, 16 min.
18 topics, 55 min.
Extraconal Pathology - Introduction
1 m.Periorbital Cellulitis & Abscess
4 m.Type 3 Orbital Infection
3 m.Solitary Fibrous Tumor
4 m.Langerhans Cell Histiocytosis
2 m.Juvenile Ossifying Fibroma
2 m.Perineural Spread of Squamous Cell Carcinoma
5 m.Proptosis from Extraosseous Extension of Prostate Metastasis
3 m.Orbital Floor Fracture
5 m.Orbital Floor Fracture with Muscle/Fat Herniation
4 m.Orbital Floor Fracture: Status Post Repair
2 m.Bilateral Orbital Fracture Repair
2 m.Periorbital Cellulitis - Review
5 m.Orbital Pseudotumor - Review
3 m.Orbital Wall Abnormalities - Review
3 m.Orbital Fracture - Review
7 m.Giant Cell Reparative Granuloma
3 m.Granulomatous Sinusitis with IgG4-related Ophthalmic Disease
4 m.6 topics, 19 min.
0:00
This was a young woman who developed painful,
0:05
irritated left eye after an insect bite on the face.
0:11
As we scroll through these scans,
0:13
you note that they are performed with contrast
0:16
administration. For infectious inflammatory conditions,
0:20
we give intravenous contrast on the CT scans.
0:24
In this situation,
0:27
what we see with regard to the left eye is swelling of
0:31
the eyelid as well as swelling of the
0:35
sclera and cornea of the left eye.
0:40
And that cornea is somewhat irregular in its contour.
0:45
You also note that the patient has a fluid
0:48
collection superficial to the cornea.
0:54
This collection is seen as showing a border of contrast
1:00
enhancement as well as a small area
1:04
of edema within the collection.
1:07
Whenever we have air in an orbital collection,
1:10
we worry about polymicrobial disease and this is treated
1:14
much more aggressively than if it's a single staphylococcus
1:19
or staphylococcal epidymitis infection. In this case,
1:22
the inflammation remains anterior to the posterior
1:28
segment of the globe and it also remains
1:32
anterior to the orbital septum.
1:36
This would be termed preseptal cellulitis and the other
1:41
term that is used is periorbital cellulitis.
1:47
Periorbital cellulitis is distinguished from orbital
1:51
cellulitis or postseptal cellulitis depending
1:55
upon whether the orbital septum is involved.
1:59
The orbital septum is a dense,
2:01
fibrous tissue which inserts on the tarsal plates of the
2:05
eyelids and it prevents anterior infections from
2:10
infiltrating the retrobulbar space of the orbit.
2:16
So let's scroll these images and make sure that the
2:19
orbital fat is not involved in the intraconal space.
2:23
So as we look here, we have a nice,
2:26
clean optic nerve and the fat in the retrobulbar
2:30
compartment looks fine compared to the contralateral
2:34
side and there is no involvement
2:36
of the postseptal space.
2:39
So this patient we would characterize as having
2:42
periorbital cellulitis with a periorbital or lid abscess
2:49
for which the patient is likely to have intravenous
2:52
antibiotic therapy. Without the abscess,
2:56
one would simply have periorbital cellulitis.
3:00
Periorbital cellulitis is a diagnosis that is made in
3:04
the emergency room and is treated with oral antibiotics
3:07
as an outpatient that's to be contrasted with
3:11
orbital cellulitis. For orbital cellulitis,
3:14
the patient is generally admitted for at least 24 hours
3:18
of intravenous antibiotics because of the risk of
3:22
involvement of the optic nerve sheath complex
3:26
and potential infectious optic neuropathy.
Interactive Transcript
0:00
This was a young woman who developed painful,
0:05
irritated left eye after an insect bite on the face.
0:11
As we scroll through these scans,
0:13
you note that they are performed with contrast
0:16
administration. For infectious inflammatory conditions,
0:20
we give intravenous contrast on the CT scans.
0:24
In this situation,
0:27
what we see with regard to the left eye is swelling of
0:31
the eyelid as well as swelling of the
0:35
sclera and cornea of the left eye.
0:40
And that cornea is somewhat irregular in its contour.
0:45
You also note that the patient has a fluid
0:48
collection superficial to the cornea.
0:54
This collection is seen as showing a border of contrast
1:00
enhancement as well as a small area
1:04
of edema within the collection.
1:07
Whenever we have air in an orbital collection,
1:10
we worry about polymicrobial disease and this is treated
1:14
much more aggressively than if it's a single staphylococcus
1:19
or staphylococcal epidymitis infection. In this case,
1:22
the inflammation remains anterior to the posterior
1:28
segment of the globe and it also remains
1:32
anterior to the orbital septum.
1:36
This would be termed preseptal cellulitis and the other
1:41
term that is used is periorbital cellulitis.
1:47
Periorbital cellulitis is distinguished from orbital
1:51
cellulitis or postseptal cellulitis depending
1:55
upon whether the orbital septum is involved.
1:59
The orbital septum is a dense,
2:01
fibrous tissue which inserts on the tarsal plates of the
2:05
eyelids and it prevents anterior infections from
2:10
infiltrating the retrobulbar space of the orbit.
2:16
So let's scroll these images and make sure that the
2:19
orbital fat is not involved in the intraconal space.
2:23
So as we look here, we have a nice,
2:26
clean optic nerve and the fat in the retrobulbar
2:30
compartment looks fine compared to the contralateral
2:34
side and there is no involvement
2:36
of the postseptal space.
2:39
So this patient we would characterize as having
2:42
periorbital cellulitis with a periorbital or lid abscess
2:49
for which the patient is likely to have intravenous
2:52
antibiotic therapy. Without the abscess,
2:56
one would simply have periorbital cellulitis.
3:00
Periorbital cellulitis is a diagnosis that is made in
3:04
the emergency room and is treated with oral antibiotics
3:07
as an outpatient that's to be contrasted with
3:11
orbital cellulitis. For orbital cellulitis,
3:14
the patient is generally admitted for at least 24 hours
3:18
of intravenous antibiotics because of the risk of
3:22
involvement of the optic nerve sheath complex
3:26
and potential infectious optic neuropathy.
Report
Description
Faculty
David M Yousem, MD, MBA
Professor of Radiology, Vice Chairman and Associate Dean
Johns Hopkins University
Tags
Orbit
Neuroradiology
Neuro
Infectious
Head and Neck
CT
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