|ECR 2018 / C-0555|
|CT and MRI of orbital masses: How can radiologist help the surgeon|
Findings and procedure details
We illustrate orbital pathology from patients who presented in our radiology department with orbit related symptoms since 2001.
Ocular ultrasound is used to discover ocular pathology.
CT technique consisted on lateral scanogram and contiguous 2 mm thickness sections at 1 mm interval for both axial and coronal planes prior to and after administration of non-ionic intra venous contrast media (2 cc/kg). Patients images were assessed in soft tissue and bone window.
MRI protocol included axial and coronal T1 & T2WI sequences, axial STIR & axial DW sequences prior to contrast administration; and axial & coronal T1LAVA images after the administration of Gadolinium.
Most of the diagnoses were confirmed by pathologist.
Ocular globe is recovered by 3 layers. The inner one is the retina. The medium one is the uvea, which divides into choroid (posterior), iris and ciliary body (anterior). The external layer is the sclera. The globe can be divided into two segments: anterior and posterior (Figure 1).
The anterior segment includes the anterior and posterior chambers; both filled by aqueous humour and separated by the lens.
The posterior segment includes the vitreous body (which contains vitreous humour), the optic disc (blind spot) and the macula lutea.
Ocular globe can be the target of a wide range of pathologies.
Behind the ocular globe, we’ll find the retroocular or retrobulbar space (Figure 2).
This region is anatomically divided into 3 spaces:
Intraconal space (Figure 3). It’s bordered by the conal space (lateral) and the optic nerve (medial). It contains the optic nerve, the ophthalmic artery & vein and intraconal fat.
Conal space (Figures 4, 5 & 6). It’s surrounded by the intraconal (medial) and extraconal (lateral) spaces. It contains the extraocular muscles. Those are superior and inferior oblique, superior, medial, lateral and inferior rectus and levator palpebrae superioris.
Extraconal space (Figures 7 & 8). It’s delimited by the conal space (medial) and the periostium and paranasal sinuses (lateral). This location contains extraconal fat and the lachrymal system, including the lachrymal gland and the lachrymal duct.
From now on, we will review the most common entities in each space (Figure 9).
Figure 10 shows the ocular pathology classified by the localisation inside the ocular globe.
Figure 11 shows the retroocular pathology, classified into optic nerve, intraconal, conal and extraconal entities. Intraconal processes are separated into vascular derived and fat derived entitites (Figure 12).
Extraocular pathology includes sphenoid wing displasia, fibrous dysplasia and meningocele/encephalocele.
BENIGN VS MALIGNANT PATHOLOGY
Once we have reviewed the processes location, we will analyze several radiological features which might be useful to differentiate benign from malignant lesions. Figure 13 gives a great summary to the reader of all these differences.
Generally speaking, a benign lesion is defined by well-defined borders, small size and no enhancement or mild enhancement with contrast, non-extra-ocular extension and mild mass effect. Nonetheless, these features are not always clear and it can lead us to commit several mistakes.
Density and intensity can be variable in benign and malignant processes. As a general rule, fat and calcium content indicates benignity. Necrosis foci is defined by an hypointensity area in CT and an hyperintensity area in T2WI with lack of enhancement. Any lesion with big size can develop necrosis foci. However, this feature is more related to malignity.
Restricted diffusion is due to the lack of movement of water molecules in presence of a huge amount of cells. These situation is more commonly associated with neoplasms than inflammatory processes.
Enhancement pattern is one of the most reliable parameters. Malignant lesions normally have an avid and heterogeneous enhancement pattern whereas benign processes show a quite homogeneous one.
Perfusion curves, finally, can help radiologist in some cases but they must be correlated with other imaging parameters. As a general rule, progressive enhancement (Type I curve) is related with benign lesions whereas Type II (avid enhacenement without washout) and Type III (avid enhancement and quick wash-out) curves are ofter related to malignant neoplasms.
To sum up, imaging features can help radiologist to do a practical approach of the diagnosis of the lesions. Nonetheless, some of them are non-specific and can let the consultant radiologist to missdiagnosis.
Case 1: Choroid melanoma. Figure 14
74 yo male with heterogeneous ocular mass in ultrasound (A). Lesion showed hyperintensity in T1WI (B), hypointensity in T2WI and FLAIR (C & D), restricted diffusion (E) and avid enhancement with Gad (F). Choroid melanoma was confirmed by pathologist.
Case 2: Choroid melanoma. Figure 15
Another case of choroid melanoma in a 74 yo male. Pay attention to the hyperintensity of signal of the lesion in T1 in figure D (arrow). Restricted diffusion of the lesion is showed in B.
Case 3: Breast metastasis. Figure 16
A case of ocular breast metastasis in a 58 yo female. Intraocular lesions showed ill-defined borders (arrow), hypointensity in T2WI (A & B) and avid enhancement with Gad (C & D).
Case 4: Scleritis. Figure 17
52 yo male with right ocular pain. Eye US (A & B) showed thickening and hypervascularity of the right sclera compared with the other side (arrow) CT confirmed the findings (C & D). Scleritis was the final diagnosis.
Case 5: Intraocular strange bodies. Figure 18
Find out how different strange objects inside the ocular globe can be. A & B pictures show wood objects and C & D show metal object inside the globe.
Case 6: Lens luxation. Figure 19
81 yo female with headache. Incidentally, NE-CT highlighted an abnormal position of the right lens inside the eye (A). B & C. T2 & T1WI confirmed these findings (arrow).
Case 7: Phthisis bulbi. Figure 20
73 yo male with Phthisis Bulbi. This entity, also known as end-stage eye, is an atrophic scarred and disorganised globe that may result from a variety of severe ocular insults.
Case 8: Uveitis & vitreous haemorrhage. Figure 21
29 yo female with left eye inflammation and pain. US showed hyperechogenic foci in the left eye. MRI revealed the presence of hyperintense foci in T1 with marked hypointensity in T2 and mild enhancement with Gad. Uveitis & vitreous haemorrhage in left eye was confirmed.
Case 9: Choroid vs retinal detachment. Figures 22 & 23
Ocular ultrasound. A, B & C showed retinal detachment with the typical triangular shape (arrow) due to retina insertion into the optic disc (posterior) and ora serrata (anterior). D, E. Choroid detachment. Remember that it’s not limited and extends beyond the ora serrata (anterior) and diverges at the optic disc (posterior). Thus, vitreous haemorrhage is appreciated in D.
Case 10: Choroid detachment. Figure 24
83 yo female who suffered a traffic accident. US showed an heterogeneous hyperechogenic intraocular mass, without Doppler flow inside and not fixed into the optic nerve. CT revealed hyperdensity of the lesion. MRI confirmed the findings. Choroid detachment was the final diagnosis.
Case 11: Retinal detachment. Figure 25
54 yo female with retinal detachment into the right eye. Pay attention to hyperintensity in T1, hypointensity in T2 (due to haemorrhage) and triangular shape of the detachment (arrowhead).
Case 12: Intraosseous meningioma. Figure 26
69 yo male with small lesion located above the left eye. A. Eye-US was normal. B & C. CT revealed the presence of an intraosseous hyperdense mass with lack of cortical destruction associated (arrow). D & E. MRI highlighted the avid enhancement of the lesion with Gad. Intraosseous meningioma was the final diagnosis.
Cases 13 & 14: Optic nerve glioma. Figures 27 & 28
Case 15: Optic nerve shealth meningioma. Figure 29
64 yo female with intraconal mass with avid enhancement in CT (A). Lesion showed hypointensity in T1WI (B), hyperintensity in T2WI & T2 STIR (C & D) and homogeneous hyperenhancement in T1 + Gad (E & F). Meningioma of the optic nerve sheath was confirmed.
Case 16: Meningioma. Figure 30
75 yo female with left conal & extraconal lesion with isointensity in T1WI (A), hyperintensity in T2WI and FLAIR (B & C), restricted diffusion (D) and avid enhancement with Gad (E & F) in connection with cavernous sinus. Meningioma was confirmed by pathologist.
Case 17: Bilateral opthalmic vein dilatation. Figure 31
74 yo female with bilateral exophthalmos. CT with and without IVC (A & B) highlighted bilateral intraconal lesions with avid enhancement. MRI with Gad confirmed these findings (E). DSA showed bilateral ophthalmic vein dilatation (F).
Cases 18 & 19: Cavernosus heamangioma. Figures 32 & 33
Case 20: Venous varix. Figure 34
84 yo male with right exophthalmos. MRI showed a nodular well-defined intraconal right lesion, hypointense in T1WI (A & B), mild hyperintense in T2WI (C, D & E) which showed avid enhancement with Gad. Venous Varix was the final diagnosis.
Case 21: Carotid-cavernous fistula. Figure 35
68 yo male with an hyperdense left intraconal lesion on NE-CT (A). MRI showed an hypointense lesion in T2WI, T1WI, T2WI & T2FATSAT (B, C, D, E). T1 + Gad confirmed the vascular origin of the lesion (F). DSA showed dilatation of the left superior ophthalmic vein (G). Carotid-Cavernous fistula was the final diagnosis.
Case 22: Breast metastasis. Figure 36
78 yo female with left compressive optic neuropathy symptoms. US revealed an intraconal mass (A) confirmed in NE-CT (B) which showed restricted diffusion (C) and avid enhancement with Gad (E & F). Breast metastasis was confirmed.
Cases 23, 24 & 25: Orbital pseudotumour. Figures 37, 38 & 39
Case 26: Orbital lymphoma. Figure 40
90 yo male with an incidental left orbital mass which occupied intraconal and extraconal spaces (A & B). Lesion showed hypointensity in T2WI (C &D), restricted diffusion and enhancement with Gad (E & F). Orbital lymphoma was confirmed by pathologist.
Case 27: Ischemic optic neurophathy. Figure 41
91 yo female with right retroocular pain. A & B. T1WI & T2WI sequences showed no pathological findings. C & D. DW & ADC sequences revealed a restricted diffusion foci in the right optic nerve. Ischemic optic neuropathy was confirmed.
Case 28: Acute right dacryoadenitis. Figure 42
40 yo female with ocular inflammation and high levels of PCR in the biochemistry. A.. CE-CT showed increased size of right lachrymal gland compared with the left one. B, C & D. MRI confirmed the findings. Pay attention to the presence of a bit quantity of fluid around the right lachrymal gland (arrow) in C. Acute right dacryoadenitis was confirmed.
Case 29: Subperiostic abscess. Figure 43
53 yo female with sinusitis symptoms. CT showed an hypodense well-defined left extraconal nodule. Lesion showed hypointensity in T1, hyperintensity in T2, restricted diffusion and heterogeneous avid enhancement with Gad. Subperiostic abscess due to sinusitis was the final diagnosis.
Case 30: Dermoid cyst. Figure 44
58 yo female with diplopia. A & B. NE-CT showed a well-defined fat-density left extraconal mass. C, D & E. MRI revealed hyperintensity of the lesion in T2 & T2FLAIR sequences and no enhancement with Gad. Dermoid Cyst of the left lachrymal gland was the diagnosis.
Case 31: Astrocitoma of the optic chiasm. Figure 45
16 yo male with diplopia. A , B, C, D & E. MRI showed an hyperintense solid mass into the optic chiasm in T2WI, with no restricted diffusion and avid enhancement with Gad. Astrocitoma of the optic chiasm was confirmed.
Case 32: Dysthyroid ophthalmia. Figure 46
52 yo female with hyperthyroidism. CT revealed thickening of both eyes medial and inferior rectus muscles. Dysthyroid ophthalmia was the final diagnosis.
Case 33: Ecrin carcinoma of the upper eyelid. Figure 47
79 yo male with lack of occlusion of the right eyelid. MRI showed a round-shaped lesion depending on palpebrae levator superioris muscle, hypointense in T2WI (A), hyperintense in T1WI (B & C) and with mild enhancement with Gad (D). Ecrin carcinoma of the right upper eyelid was the diagnosis.
Case 34: Cribiform carcinoma of the infraorbitary nerve. Figure 48
71 yo male with sinusitis. In CT Scan (A), a soft tissue density lesion located on the infraorbital nerve channel was observed (arrow). MRI showed hyperintensity of the lesion in T2 (B) and avid hyperenhancement with Gad (D). Biopsy revealed cribiform carcinoma of the infraorbital nerve.
Case 35: Orbital pseudotumour. Figure 49
78 yo female with an intraconal mass in US (A) and CT (B). Lesion showed hypointensity in T1 (C y D), mild hyperintensity in T2 (E), restricted diffusion (F) and avid enhancement with Gad (G & H). Radiologist consultant diagnosis was intraconal lymphoma. Orbital pseudotumour was the final diagnosis. As a general rule, restricted diffusion is more associated with malignant processes.
Thematically related posters
ECR 2018 / C-0653
A Pictorial Review of Common and Unusual Presentations of Epidermoid Cysts in the Central Nervous System
ECR 2018 / C-3022
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