Faculty Bibliography

PURPOSE/OBJECTIVE:Immunoglobin G4 (IgG4)-related disease is a systemic condition characterized by lymphoplasmacytic infiltrates that can involve the orbit. The purpose of this study was to identify the various patterns of orbital IgG4-related disease on imaging. METHODS:Retrospective review of radiologic examinations including CT, MRI, and positron emission tomography was performed in patients with proven cases of IgG4-related disease. RESULTS:A total of 9 patients with orbital IgG4-related disease were identified, including 9 with CT, 4 with MRI, and 4 with 18-fluorodeoxyglucose positron emission tomography. Patterns of involvement included lacrimal gland enlargement, lacrimal sac involvement, extraocular muscle thickening, preseptal involvement, orbital fat involvement, and cranial nerve involvement, many of which occurred simultaneously. Associated demineralization of the orbital wall was evident on CT in 2 cases. On T2-weighted MRI, the lesions appeared as hypointense in 2 cases, heterogeneously hypointense to isointense in 1 case, and hyperintense in 1 case. Diffuse enhancement was present in all 3 cases in which postcontrast T1-weighted sequences were available. The lesions were hypermetabolic on positron emission tomography in 3 of 4 cases. There was definite extraorbital involvement by IgG4-related disease in 3 of the 9 patients and suspected involvement in another 3 of the 9 patients. CONCLUSIONS:IgG4-related disease displays a wide variety of imaging manifestations in the orbit. Extraorbital disease is often present and can help suggest the diagnosis.

OBJECTIVE:Until now, the use of computed tomography (CT) in the diagnosis and evaluation of otosclerosis has been based on correlation of radiologic findings to patient histories, intraoperative examinations, and audiologic data. The purpose of this study was to compare CT findings in otosclerosis to histopathology. STUDY DESIGN/METHODS:Prospective blinded. SETTING/METHODS:Radiology department in a tertiary referral hospital and otopathology laboratory. PATIENTS/METHODS:Temporal bones from patients with otosclerosis and other otologic diseases (used as controls). INTERVENTION(S)/METHODS:Blinded review of specimen CT scans by radiologists and comparison of CT findings to histopathology of the same bones. MAIN OUTCOME MEASURE(S)/METHODS:Ability of CT to diagnose otosclerosis, identify otosclerotic foci in defined zones of the otic capsule, determine endosteal layer involvement, oval window (OW) obliteration, and round window (RW) obliteration. RESULTS:In a randomized blinded evaluation, radiologists identified 8 of 10 bones with otosclerosis and made 3 false-positive diagnoses from the 36 control bones. Radiologic examination correctly identified otosclerosis anterior to the oval window, in the pericochlear area, and in the round window niche in 17 of 17, 9 of 11, and 3 of 6 bones, respectively. CT correctly determined involvement of the endosteal layer, OW obliteration, and RW obliteration in 5 of 8, 2 of 2, and 2 of 2 temporal bones. CONCLUSION/CONCLUSIONS:High-resolution CT is highly sensitive and specific for the diagnosis of otosclerosis when compared with histopathology. Very small and subtle otosclerotic foci seen on pathology may be missed on CT. Although CT was able to positively identify cochlear endosteal margin involvement, the false-negative rate on CT was significant.

Neurogenic compromise of vocal fold function exists along a continuum encompassing vocal cord hypomobility (paresis) to vocal fold immobility (paralysis) with varying degrees and patterns of reinnervation. Vocal fold paralysis (VFP) may result from injury to the vagus or the recurrent laryngeal nerves anywhere along their course from the brainstem to the larynx. In this article, we review the anatomy of the vagus and recurrent laryngeal nerves and examine the various etiologies of VFP. Selected cases are presented with discussion of key imaging features of VFP including radiologic findings specific to central vagal neuropathy and peripheral recurrent nerve paralysis.

Acute ischemic stroke imaging is one of the leading causes of death and disability worldwide. Neuroimaging plays a crucial role in early diagnosis and yields essential information regarding tissue integrity, a factor that remains a key therapeutic determinant. Given the widespread public health implications of stroke and central role of neuroimaging in overall management, acute stroke imaging remains a heavily debated, extensively researched, and rapidly evolving subject. There has been recent debate in the scientific community due to divided opinions on the use of CT perfusion and access-related limitations of MRI. In this paper we review and summarize recent updates relevant to acute stroke imaging and propose an imaging paradigm based on the recently available evidence.

BACKGROUND:Hydrogel scleral buckles were used for treating retinal detachment in the 1980s and early 1990 s. However, these devices have a propensity to degrade over time and cause several long-term complications, including hydration and overexpansion, fragmentation, extrusion, intrusion, and intraocular erosion, and the potential to mimic mass lesions. METHODS:The imaging features of hydrogel scleral buckles and their complications are reviewed in this article. RESULTS:Radiographic imaging plays an important role in managing patients with complications of hydrogel buckles. Hydrated buckles display attenuation intermediate between fluid and soft tissue on computed tomography, demonstrate approximately fluid signal on magnetic resonance imaging, and are anechoic on ultrasonography. Linear margins and peripheral dystrophic calcification are characteristic. CONCLUSION/CONCLUSIONS:The constellation of imaging features helps distinguish expanded hydrogel buckles from other orbital diseases. Imaging also serves to precisely localize hydrogel scleral buckle components requiring removal.

Perineural tumor spread (PNS) is a mode of neoplastic spread whereby tumor cells use neural conduits to escape the borders of a primary tumor. MRI is generally favored over CT for evaluating PNS, and findings include obliteration of fat within skull base foramina, enlargement and enhancement of the involved nerves, and enlargement and destruction of the bony foramina. Careful examination of the entire course of the nerve allows detection of skip lesions. Recognition of the complete extent of PNS is crucial for correct treatment because it facilitates both surgical and radiotherapy targeting of entire extent of disease.