The use of computed tomography and ultrasonography in the evaluation of orbital masses

Orbital ultrasonography in the diagnosis of neoplastic extraocular muscle enlargement

Neoplastic infiltration of the extraocular muscle (EOM) is a rare condition which can pose a diagnostic dilemma due to its rarity and overlapping ultrasonographic features with orbital myositis. The ultrasonographic features of neoplastic enlargement of EOM have not been systematically studied and previously have been described in only a few case reports. Orbital ultrasonography, in conjunction with the pattern of ocular misalignment, was assessed for its potential role in identifying patients with neoplastic EOM enlargement. Retrospective chart review of patients with neoplasm and myositis. The clinical features of 8 patients with neoplastic infiltration of the EOM were compared to 15 patients with myositis. In the neoplastic group the width of the EOM was (10.5 mm) almost twice the normal width of the muscle with myositis (p < 0.001). All the muscles in the neoplastic category were low to medium reflective. Paretic deviation was seen in 4/8(50%), purely restrictive in 2/8 (25%) and combined pattern in 2/8 (25%) were noted. In the myositis group the average EOM enlargement was 5.8 mm and all muscles showed low reflectivity. Although ultrasonographic features overlapped between the 2 groups paretic deviations were more common in the neoplastic group versus the myositis group (50% versus 7%). Neoplastic muscle enlargement tends to be larger with paretic deviations of ocular motility seen clinically. These findings in a patient with EOM enlargement should raise the suspicion of neoplasm as the etiology and further work up should be considered.

Correlation between magnetic resonance imaging and ultrasound measurements of eye muscle thickness in thyroid-associated orbitopathy

AIMS

To compare ultrasound (US) and magnetic resonance imaging (MRI) measurements of horizontal eye muscle thickness in patients with thyroid-associated orbitopathy (TAO) and to compare these measurements according to the phase of the disease, the severity of exophthalmos, and the experience of the investigator.

METHODS

A total of 180 orbits of adult patients with TAO were investigated from May 2007 to December 2012. In addition to their general ophthalmic examination, all patients underwent ultrasonographic measurement of horizontal eye muscle thickness with the B-scan technique and MRI examination of the orbit. Correlations between values obtained by US and MRI were determined for different subgroups according to disease activity (active, inactive), exophthalmos values (Hertel < 18 mm; Hertel 18-22 mm; Hertel > 22 mm), and the time period of examination (2007-2009; 2010-2012).

RESULTS

Positive moderate correlation between US and MRI values for the medial rectus muscle (MRM; r = 0.690) and for the lateral rectus muscle (LRM; r = 0.572) was found. Significantly higher correlation was found for the MRM (P < 0.0001) and the LRM (P = 0.0008) in the time period 2010-2012 than in that of 2007-2009. Increasing correlation was found for MRM with increasing values of exophthalmos but this increase was not statistically significant. In the active phase of the disease compared to the inactive phase, statistically significant increased correlation (P = 0.019) was found for the LRM.

CONCLUSIONS

Ultrasonographic measurement of horizontal eye muscles thickness in TAO moderately correlates with values obtained using MRI. The accuracy of ultrasonographic measurements in particular increases with the experience of the investigator.

Ultrasonography compared to magnetic resonance imaging in thyroid-associated Graves' ophthalmopathy

OBJECTIVE

To compare ultrasonography (US) to magnetic resonance imaging (MRI) and the clinical activity score (CAS) in Graves' ophthalmopathy.

SUBJECTS AND METHODS

Nineteen patients underwent extraocular muscle thickness measurements by US and MRI, reflectivity by US and signal-intensity ratio by MRI. There were also twelve US control subjects.

RESULTS

US median thicknesses were greater than in controls. Correlation was found between US and MRI in the median thickness of the left eye rectus medial muscle as well as between signal-intensity ratio (SIR) and thickness by US. An inverse correlation was found between reflectivity and SIR in the inferior and lateral rectus. On associating the tests for detecting activity the best results were obtained with CAS plus MRI (sensitivity 75%), and US and MRI (positive predictive value 77% and specificity 80%).

CONCLUSION

CAS and US results showed poor correlation with MRI results suggesting that they cannot replace each other but when combined these methods can improve the evaluation of thyroid-associated ophthalmopathy.

Intra-lacrimal gland cavernous hemangioma

Orbital cavernous hemangioma usually has a typical clinical and imagery pattern. We present a patient with an enlarged lacrimal gland due to an intra-gland cavernous hemangioma.

Assessment of ultrasonography and computed tomography for the evaluation of unilateral orbital disease in dogs

OBJECTIVE

To describe clinical, ultrasonographic, and computed tomographic (CT) features of confirmed neoplastic and nonneoplastic disease in dogs with unilateral orbital diseases, determine criteria to differentiate between the 2 conditions, and assess the relative value of ultrasonography and CT for the differential diagnosis of these 2 conditions.

DESIGN

Prospective study.

ANIMALS

29 dogs with unilateral neoplastic orbital disease and 16 dogs with unilateral nonneoplastic orbital disease.

PROCEDURES

Clinical history and results of physical and ophthalmologic examinations were recorded. Ultrasonographic and CT images were evaluated, and discriminating factors were identified to differentiate neoplastic from nonneoplastic diseases. Diagnostic value of ultrasonography and CT was assessed.

RESULTS

Dogs with neoplastic disease were significantly older; had clinical signs for a longer time before initial examination; had more progressive onset of clinical signs; and more frequently had protrusion of the nictitating membrane, fever, and anorexia. The most discriminating factor for both imaging modalities was delineation of the margins (odds ratio was 41.7 for ultrasonography and 45 for CT), with neoplastic lesions clearly delineated more often. Ultrasonographically, neoplastic lesions were more frequently hypoechoic and homogeneous, with indentation of the globe and bone involvement evident more frequently than for nonneoplastic lesions. Mineralization was detected only with neoplasia. Fluctuant fluid was seen more frequently in dogs with nonneoplastic disease. Computed tomography more frequently revealed extraorbital involvement. Diagnostic value was similar for both imaging modalities.

CONCLUSIONS AND CLINICAL RELEVANCE

Ultrasonography and CT are valuable imaging modalities to assist in differentiating neoplastic from nonneoplastic unilateral orbital disease in dogs.

Evaluation and Management of Graves' Orbitopathy

Graves' orbitopathy, also known as Graves' ophthalmopathy or thyroid eye disease, is a potentially progressive but generally self-limited autoimmune process associated with hyperthyroidism. It is the most common cause of proptosis and the most common orbital inflammatory disorder in adults.

The role of Tc-99m polyclonal human immunoglobulin G scintigraphy in Graves' ophthalmopathy

OBJECTIVE

The aim of this study was to clarify whether Tc-99m HIG (Polyclonal Human Immunoglobulin G) can image and determine the severity of orbital involvement in patients with Graves' ophthalmopathy.

MATERIALS AND METHODS

Twenty-six patients between 19 and 56 years old with Graves' ophthalmopathy were examined. All patients received approximately 370 MBq Tc-99m HIG by i.v. injection. Planar and SPECT examination were performed 4 hours after the injection. Visual and semiquantitative evaluations were performed for both orbits by two independent observers,

RESULTS

Clinically active ophthalmopathy patients had noticeably increased orbital accumulation of Tc-99m HIG. In patients with inactive disease, and 14 of 19 had no uptake, whereas 5 patients had orbital radioactivity accumulation. The duration of Graves' ophthalmopathy did not correlate with the presence of active ophthalmopathy and Tc-99m HIG grade. There was no correlation between clinical classification and clinical activity (r = 278). There was a good correlation between clinical activity and the radioactivity grade with r = 0.666 (p = 0.01). The clinical classification closely correlated with Tc-99m HIG grade (r = 0.423, p = 0.05).

CONCLUSION

Tc-99m HIG scan can clearly identified clinically active patients, and subclinicial inflammation can be shown by this scintigraphic evaluation. The current preliminary results suggested that Tc-99m HIG SPECT might be useful for the assessment of disease activity in Graves' ophthalmopathy.

Pseudo-pseudotumor

The initial diagnostic impression in a patient with a "hot orbit" may evolve as more laboratory and radiographic information becomes available. We present a patient in whom nearly the entire differential diagnosis of painful orbitopathy was considered before the correct diagnosis was made, after the patient had improved and all paraclinical data, including magnetic resonance imaging, were available.

Thyroid eye disease

Thyroid eye disease is the most common cause of unilateral and bilateral proptosis in adults. It occurs most frequently in women aged 30 to 50 years. Clinical features include eyelid retraction, periorbital edema, conjunctival injection and chemosis, proptosis, extraocular muscle restriction, exposure keratopathy, and optic nerve compromise. Thyroid eye disease differs from idiopathic orbital myositis in that the latter is characterized by a more acute onset, more severe pain, and a rapid response to systemic corticosteroid therapy. Echography and computed tomography in thyroid eye disease reveal enlarged extraocular muscle bellies with relative sparing of the tendons. Despite evidence of an immune-mediated cause, the precise pathophysiologic mechanisms of thyroid eye disease remain unknown.

Management of orbital tumors

Orbital tumors are uncommon. In children, both malignant and benign causes of orbital proptosis necessitate urgent assessment; in many cases, emergent intervention is necessary to avoid blindness. In adults, proptosis is most commonly associated with thyroid orbitopathy. Orbital tumors in adults rarely are characterized by the explosive growth and damage that can occur with childhood lesions. In both age-groups, the evolution of better scanning modalities, such as magnetic resonance imaging with fat saturation and gadolinium enhancement, has improved diagnostic accuracy, especially in patients with loss of vision. In more than 95% of cases, noninvasive techniques yield a correct diagnosis. In patients who require nonsurgical intervention, especially if the diagnosis is uncertain, fine-needle aspiration biopsy has an accuracy that exceeds 95%. Combined-modality therapy has improved the control of and decreased the morbidity associated with several orbital tumors. Surgical advances, such as the ancillary use of the CO2 laser, have enhanced the management of some orbital tumors.

Benign mixed tumors arising in the palpebral lobe of the lacrimal gland

The accurate clinical diagnosis of benign mixed tumors of the lacrimal gland is imperative for proper therapeutic management. Although benign mixed tumors of the orbital portion of the lacrimal gland have an established identity, those tumors arising in the palpebral lobe are unusual. Four patients with benign mixed tumors of the palpebral lobe are presented, emphasizing the confusion that exists in making the diagnosis. Palpebral lobe benign mixed tumors should be strongly considered in the differential diagnosis of upper outer eyelid masses. En bloc resection avoids the risk of tumor spillage, recurrence, and/or malignant transformation caused by preliminary biopsy or incomplete resection.

Cytologic and biochemical examination of the subretinal fluid in diagnosis of Coats' disease

Two babies presenting with unilateral leukocoria were found to have total retinal detachment in one eye, associated with subretinal yellowish-white deposits. As no calcification was found and subretinal fluid aspiration yielded many fat-laden macrophages without any evidence of retinoblastoma cells in addition to a high level of cholesterol, the difinitive diagnosis of Coats' disease was made. Subsequently, retinal detachment surgery and cryotherapy were performed, in an attempt to preserve the affected eye.

Enlargement of levator palpebrae superioris muscle fibers in Graves' ophthalmopathy

Enlargement of the extraocular muscles in Graves' ophthalmopathy is attributed to inflammation and fibrosis. This is the first report of the histology and morphometry of the levator palpebrae superioris (LPS) muscle proximal to Whitnall's ligament in Graves' ophthalmopathy. Four thousand computer-assisted levator muscle fiber measurements in 16 control and abnormal levator palpebrae superioris muscle biopsies were done. These measurements showed statistically significant levator muscle fiber enlargement in the Graves' ophthalmopathy specimens. There was minimal evidence of inflammation. These findings suggest that muscle fiber enlargement is an important cause of the characteristic hypertrophy of the levator muscle in Graves' ophthalmopathy. Levator muscle fiber enlargement is a likely cause of upper eyelid retraction in Graves' ophthalmopathy.

Bilateral orbital cavernous haemangiomas

Simultaneous bilateral orbital lesions are rare. The differential diagnosis includes orbital pseudotumour, metastasis, leukaemia, lymphoma, Wegener's granulomatosis, and neurofibromatosis. We report what we believe to be the first case of bilateral orbital cavernous haemangiomas.

High field resolution magnetic resonance imaging of malignant choroidal melanoma

High resolution surface receiver coil nuclear magnetic resonance imaging (MRI) of the eye and paraorbital areas was performed in a patient with a malignant choroidal melanoma before and after local radiotherapy using ruthenium application. The resulting improvement in signal-to-noise ratio allows for a reduction in the imaging voxel size to 0.31 X 0.31 X 3 mm3 which provided useful morphological information with respect to delineation of tumoral mass. In the same MRI session using a standard head coil imaging method, T1 and T2 relaxation time values were calculated in regions of interest of 3 X 3 mm by means of transversal scan images of orbital and cranial tissues performed in scan times of 7 to 9 minutes. The procedure presented here combines in one single session high resolution imaging performance, previously unobservable in MRI and in other noninvasive imaging techniques, with fast and reliable measurement of T1 and T2 relaxation times within small regions of interest. MRI, a non ionizing technique, offers within reasonable acquisition times not only a good multiplanar description of the site, size and volume of normal and pathologic orbital structures, but, in addition, the prospect of soft tissue differentiation and of accurately documenting the response to and side effects of the therapy of ocular tumors.

Benign mixed tumor of the palpebral lobe of the lacrimal gland. Clinical diagnosis and appropriate surgical management

The treatment of suspected benign mixed tumor (pleomorphic adenoma) of the lacrimal gland consists of wide local surgical excision of the tumor and its capsule in their entirety. The tumor should be approached routinely via a lateral orbitotomy to provide maximal exposure and allow complete removal of the lesion. However, if clinical and radiographic evidence indicates a far anterior location implying an origin in the more superficial palpebral lobe, an anterior transcutaneous approach is advantageous and preferred. The authors report an adult case of an anteriorly located benign mixed tumor of the palpebral lobe of the lacrimal gland. The authors reviewed the characteristic clinical, echographic, and computed tomographic (CT) features, offered a differential diagnosis, and described surgical removal using a cryoprobe via an anterior lid approach. An awareness of the distinctive clinical and diagnostic features of benign mixed tumor of the palpebral lobe should help to avoid the complications that ensue from an incisional biopsy or piecemeal resection through the lid, and also to avoid the need for more extensive surgery for removal of residual or recurrent tumor.

Special diagnostic and therapeutic modalities in pediatric ophthalmology

Ophthalmology is a specialty rich in instrumentation used for special diagnostic and therapeutic functions. Many of these special modalities are appropriate to pediatric ophthalmology, and this article discusses them in summary fashion for those who may wish to know about the procedures but who may not be involved directly in their use.

Orbital computed tomography. Does it help in diagnosing the infiltration of choroid, sclera and/or optic nerve in retinoblastoma?

High-resolution computerized tomography of the orbit was performed in patients with histologically proven retinoblastoma to assess the efficacy of CT in delineating the retro-orbital extent of the tumor and determining if the optical nerve was involved. High-resolution CT proved able to accurately delineate tumor size, tumor localization, tumor calcification, retro-orbital and intracranial tumor growth. Microscopical tumor spread past the lamina cribrosa of the optic nerve, however, could not be detected by CT.

Sonography and computed tomography in the diagnosis of orbitocranial malformations and tumors

Standardized sonography and CT scanning have distinct advantages and disadvantages in the evaluation of patients with orbital diseases. Echography provides an efficient screening examination in patients presenting with signs and symptoms of orbital pathology. It allows the detection, localization, measurement and in almost 80% differentiation of orbital lesions. High resolution CT scanning gives an excellent topographic display of masses in the orbit. In visualization of intracranial causes of orbital processes and demonstration of changes in the posterior third of the orbit, in the orbital bones and the periorbital sinuses it is superior to ultrasonography.

Acute orbital pseudotumor with iatrogenic intraorbital air: a diagnostic dilemma

A 13-year-old black female was referred with unilateral granulomatous uveitis and orbital inflammation of sudden onset. Hematologic, serologic, bacteriologic, and ultrasonographic studies along with high resolution CT scans of the orbits were employed to determine the diagnosis and appropriate treatment. Subconjunctival corticosteroid injection containing air prior to referral obfuscated the ultimate diagnosis of pseudotumor. The Pediatric Infectious Disease service delayed definitive treatment with systemic steroids. Differential diagnosis of granulomatous uveitis with orbital inflammation are discussed. CT scan has significantly advanced the diagnosis and management of orbital pseudotumor.

Magnetic resonance scanning in orbital tumor diagnosis

We have compared the accuracy of magnetic resonance scanning (MRI) versus computed tomography (CT) in the differentiation of lateral orbital masses. The MRI results did not improve our ability to accurately diagnose malignant epithelial and lymphoid tumors.

Fine needle aspiration biopsy in ophthalmology

When noninvasive techniques fail to confirm or rule out the suspicion of a malignant lesion, fine needle aspiration biopsy may provide an efficient, economical and relatively safe method of obtaining material for cytological study. The technique may also be valuable for intraoperative morphological evaluation. Traumatic complications produced by fine (21-25 gauge) needles are infrequent and almost never serious, and concerns about tumor seeding through the procedure have been largely dispelled by recent studies. Reliable results require a high level of skill in performing the aspiration procedure and in cytologically examining the small amount of material obtained. The authors review the history, applications, techniques and complications of fine needle aspiration biopsy, presenting guidelines for and illustrations of its use in specific ophthalmic situations.

Diagnostic methods in orbital diseases

Development of diagnostic methods for orbital diseases have practically revolutionized the approach to the patient with orbital disease. These newer methods have helped the clinician to improve the accuracy of the clinical diagnosis prior to biopsy, to localize the area to be biopsied, and to prevent inappropriate surgery. These techniques have also allowed the pathologist to render more definitive diagnosis. These methods include ultrasound, computerized axial tomography, nuclear magnetic resonance imaging, fine-needle aspiration biopsy, histochemistry, immunohistochemistry and electron microscopy. The techniques are complementary, and use of each depends on the clinical situation. Some techniques require collaboration between the surgeon and pathologist to assure proper fixation and preparation of tissues.

Surgical approaches to the orbit. Indications and techniques

The authors review their experience with over 300 patients with orbital tumors, and summarize their surgical techniques and indications for each surgical approach. A fronto-orbital approach is described which is used for tumors with intracranial extension and for those located in the orbital apex and deep medial orbital compartment. Lateral micro- orbitotomy is used for tumors located in the superior, temporal, or inferior compartment of the orbit and those in the lateral apex. A medial microsurgical approach is used for tumors located medial to the optic nerve but not deep in the apex. By thus approaching tumors directly, optimal exposure is obtained and functional deficits are minimized. The pertinent surgical anatomy is illustrated and the technique of fine-needle aspiration biopsy is discussed.

Computed tomography in the diagnosis of retinoblastoma

The role of orbital computed tomography (CT) in the management of retinoblastoma is reviewed. All 21 patients with retinoblastoma studied with high-resolution computed tomography had intraocular calcification demonstrable in at least one eye. 83% of tumours showed evidence of calcification on CT scan. The degree of calcification appeared to depend on tumour size; only small tumours were devoid of calcification. The amount and distribution of calcification was similar on both histological study and CT scan. In patients under 3 years old in whom a retinoblastoma is suspected the presence of calcification on CT is virtually diagnostic of it. Patients with leucocoria without calcification on CT probably have a simulating lesion.

Nuclear magnetic resonance imaging of the orbit

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