glenn yiu, hms-iii gillian lieberman, mderadiology.bidmc.harvard.edu/learninglab/central/yiu.pdf ·...

Glenn Yiu, HMS-IIIGillian Lieberman, MD

Glenn YiuGillian Lieberman, MD

Imaging of the Orbit

March 2007

History: •

53 y/o

male with type II DM and history of

proptosis, who presents with visual complaints in the right eye

Exam: •

Bilateral proptosis

L>R

•

Visual acuity normal•

No relative afferent pupillary

defect bilaterally

•

Optic cup enlargement in R eye

Our Patient GB


Inflammation/Infection•

Orbital pseudotumor

•

Thyroid ophthalmopathy•

Sarcoid

•

Orbital cellulitis•

Abscess


Differential DiagnosisNeoplastic

•

Lymphoma•

Dermoid

•

Metastases

Vascular•

Hemangioma

•

Vascular malformations

RULE OUT:

• lid lag• relative enophthalmos• external swelling


Orbit Anatomy

(Wichmann & Muller-Forell, Eur

J Radiol. 2004)

Eyeball

Zygomaticbone

Lateral rectus

Intraconal

fat

Optic nerve

Extraconal

fat

Medial rectus

Annulus of Zinn

Ethmoid

sinus

Globe


Orbit AnatomyEyeball

Zygomaticbone

Lateral rectus

Intraconal

fat

Optic nerve

Extraconal

fat

Medial rectus

Annulus of Zinn

Intraconal

space

Muscle cone

Extraconal

space


J Radiol. 2004)

Globe


Orbit AnatomyEyeball

Zygomaticbone

Lateral rectus

Intraconal

fat

Optic nerve

Extraconal

fat

Medial rectus

Annulus of Zinn

Intraconal

space

Muscle cone

Extraconal

space

Optic nerve gliomaMeningiomaVarix

Orbital pseudotumorThyroid ophthalmopathy

Orbital cellulitis(Wichmann & Muller-Forell, Eur

J Radiol. 2004)


Orbital Imaging TechniquesCTMRI

CT•

+ most versatile•

+ bony detail or calcifications•

+ temporal / spatial resolution•

-

radiation-induced cataracts•

-

beam hardening artifacts from dental fillings

MRI:•

+ better for optic nerve and tumors•

+ no radiation•

-

poor temporal resolution•

-

must screen for metallic foreign bodies in orbit before MRI

(Wichmann & Muller-Forell, 2004)(Wichmann & Muller-Forell, 2004)


Orbital Imaging TechniquesCTMRIUltrasoundPlain filmAngiography

Angiography:•

good for vascular malformations and vascularized

tumors•

invasive and time-consuming

Plain film:•

mainly for screening for metallic foreign bodies before MRI

•

useless for soft tissue details

Ultrasound:•

good for lesions within globe or foreign bodies in orbit

•

poor penetration


Orbit Anatomy on CT


J Radiol., 2004)

1.

Zygomatic

bone2.

Nasal septum3.

Lacrimal

gland4.

Sclera5.

Vitreous body6.

Optic nerve7.

Medial rectus8.

Lateral rectus9.

Superior orbital fissure10.

Optic canal11.

Pituitary gland12.

Ethmoid

sinus13.

Sphenoid sinus

123 4 5

67

8

910

11

12

13


Orbit Anatomy on CT


J Radiol., 2004)

1.

Optic nerve2.

Ophthalmic artery3.

Superior rectus4.

Inferior rectus5.

Medial rectus6.

Lateral rectus7.

Superior oblique8.

Ethmoid

sinus9.

Maxillary sinus10.

Inferior turbinates11.

Zygomatic

bone12.

Frontal bone

12

73

456

9 9

10

8 8

12

11


Normal MRI of the Orbits


J Radiol., 2004)

Fat-saturation improves ability to visualizeoptic nerve due to retro-orbital fat

Axial and coronalnon-contrast CT of orbits

Radiological findings: Our Patient GB


(Wichmann & Muller-Forell, 2004)

Normal


Bilateral proptosis

(PACS, BIDMC, 2007)

Patient GB’s Findings on Axial CT


Extra-occular muscle enlargement

(PACS, BIDMC, 2007)

* **

*

* *

Bilateral enlargement of all extra-occularmuscles, including superior obliques

Patient GB’s Findings on Coronal CT



(PACS, BIDMC, 2007)

* *

Bilateral enlargement of all extra-occularmuscles, including superior obliques

Center enlargement with no involvement of tendons



Normal fat

(PACS, BIDMC, 2007)

* *

* *

No fat stranding

Patient GB’s Findings on Axial/Coronal CT


Grave’s Ophthalmopathy

(PACS, BIDMC, 2007)

Proptosis


Central enlargement with sparing of tendons

I’M SLow (inferior, medial, superior, & lateral rectus)



Grave’s Ophthalmopathy

(www.uptodate.com)


Grave’s Ophthalmopathy: Pathogenesis

An autoimmune disease of retroorbital tissues that occurs in 20-25% of patients with Graves’ disease, more often in women than in men.

Antibodies activate TSH receptors not only in thyroid tissue, but also in orbital fibroblasts and adipocytes.

T-cell activation stimulates secretion of glycosamino-glycans (GAG), mostly hyaluronic acid, resulting in increased volume of both extraocular muscles and retroorbital connection/adipose tissues.

Risk factors include genetics, female sex, smoking, and radioiodine therapy.


Grave’s Ophthalmopathy: ClassificationWerner classification (mnemonic: NO SPECS)

•

Grade 0: No signs or symptoms•

Grade 1: Only signs (lid retraction)•

Grade 2: Soft tissue involvement (chemosis, etc)•

Grade 3: Proptosis

(minimum <23, moderate, marked >28)•

Grade 4: Extraocular

muscle involvement•

Grade 5: Corneal involvement•

Grade 6: Sight lossAdditional signs of Thyroid eye disease

•

Dalrymple’s

sign: Lid retraction•

von Graefe’s

sign: Upper lid lag on downward gaze•

Griffith’s sign: Lower lid lag on downward gaze•

Boston’s sign: Jerky irregular movement of the upper lid on downward gaze•

Jellinek’s

sign: Increased pigmentation of the lids•

Stellwag’s

sign: Infrequent blinking•

Kocher’s sign: Increased lid retraction with visual fixation•

Enroth’s

sign: Puffy swelling of the lids•

Rosenbach’s

sign: Tremor of closed lids•

Mobius’

sign: Weakness of convergence•

Ballet’s sign: Palsy of one or more extraocular

muscles•

Suker’s

sign: Weakness of fixation on lateral gaze•

Cowen’s sign: Jerky papillary contraction to consensual light•

Knies’

sign: Unequal dilatation of the pupils•

Jeffrey’s sign: Absence of forehead wrinkling on upward gaze

(PACS, BIDMC, 2007)


Grave’s Ophthalmopathy: TreatmentGlucocorticoid therapyExternal orbital radiationOrbital decompression surgery

Patient GB was s/porbital decompression



Differential DiagnosisInflammation/Infection

•Orbital pseudotumor•Thyroid ophthalmopathy•Sarcoid•Orbital cellulitis•Abscess

Neoplastic•Lymphoma•Dermoid•Metastases

Vascular•Hemangioma•Vascular malformations


Orbital Pseudotumor

(Courtesy of Fabio Komlos, BIDMC)

Inflammation/Infection•Orbital pseudotumor•Thyroid ophthalmopathy•Sarcoid•Orbital cellulitis•Abscess



*

Fat strandingTendon not spared

Companion Patient Findings on Axial/Coronal CT





Preseptal & Postseptal Cellulitis

(Caruso et al., Radiology, 2006)

Unilateral Sinus involvement

Companion Patient Findings on Axial CT


Orbital Lymphoma

(http://www.uhrad.com/mriarc/mri049.htm)




Radiologically difficult to distinguish from orbital pseudotumor

Companion Patient Findings on Axial CT


Cavernous Hemangioma

(http://mni.mcgill.ca/neuroimage/nov2001/nov2001_p6.htm)




Well-defined massProgressive peripheral to

center enhancement post-gado

Companion Patient Findings on MRI

Agarwal A. Handbook of Ophthalmology. 2006.Aviv RI, Casselman J. Orbital imaging: Part 1. Normal anatomy. Clin Radiol. 2005 Mar;60(3):279-87. Aviv RI, Miszkiel K. Orbital imaging: Part 2. Intraorbital pathology. Clin Radiol. 2005 Mar;60(3):288-307. Belden CJ, Zinreich SJ. Orbital imaging techniques. Semin Ultrasound CT MR. 1997 Dec;18(6):413-22. Braffman BH, Naidich TP, Chaneles M. Imaging anatomy of the normal orbit. SeminUltrasound CT MR. 1997 Dec;18(6):403-12. Caruso PA, Watkins LM, Suwansaard P, Yamamoto M, Durand ML, Romo LV, Rincon SP, Curtin HD. Odontogenic orbital inflammation: clinical and CT findings--initial observations. Radiology. 2006 Apr;239(1):187-94. Davies TF. Pathogenesis and clinical features of Graves’ ophthalmopathy(orbitopathy). www.uptodate.com.Davies TF. Treatment of Graves’ ophthalmopathy (orbitopathy). www.uptodate.com.Wichmann W, Muller-Forell W. Anatomy of the visual system. Eur J Radiol. 2004 Jan;49(1):8-30.

References


Fabio Komlos, MDMichael Geary, MDGillian Lieberman, MD

Pamela LepkowskiLarry Barbaras

Acknowledgements


glenn yiu, hms-iii gillian lieberman, mderadiology.bidmc.harvard.edu/learninglab/central/yiu.pdf ·...

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