Variant 2: Acquired conductive hearing loss secondary to cholesteatoma or neoplasm with suspected intracranial or inner ear extension. Surgical planning. CT Temporal Bone High-spatial resolution CT of the temporal bone is helpful in defining small inflammatory or neoplastic masses within the middle ear cavity [1,2,13]. In addition, CT can help in surgical planning by demonstrating erosions of ossicles or other inner ear structures (such as perilymphatic fistulae) caused by such masses [14]. Given the surrounding dense bone, IV contrast is usually not beneficial in studying enhancement characteristics of middle ear masses. However, contrast enhancement may help delineate extraosseous soft tissue associated with invasive neoplasms. CT Head There is no evidence to support use of CT head for assessment of patients with conductive hearing loss and middle ear mass identified on otoscopy. CTA Head There is no definite evidence to support use of CTA as a first-line modality for assessment of patients with conductive hearing loss and middle ear mass identified on otoscopy. However, in patients with high clinical suspicion of middle ear paraganglioma, CTA is sometimes used initially for diagnostic confirmation and for planning further management. MRI Head and Internal Auditory Canal Extent of a middle ear cavity mass identified on otoscopy in a patient with conductive hearing loss is much better defined using MRI obtained without and with IV contrast [2,5,13,15]. This assessment is better done using thin sections across the temporal bone as part of a dedicated internal auditory canal (IAC) protocol rather than a routine brain MRI. Excellent soft-tissue contrast afforded by even a noncontrast MRI often complements the bony details seen on temporal bone CT for complete evaluation of such patients prior to surgical intervention. MRA Head MRA is usually not used as a first-line imaging modality in patients presenting with conductive hearing loss.
Hearing Loss and or Vertigo. Variant 2: Acquired conductive hearing loss secondary to cholesteatoma or neoplasm with suspected intracranial or inner ear extension. Surgical planning. CT Temporal Bone High-spatial resolution CT of the temporal bone is helpful in defining small inflammatory or neoplastic masses within the middle ear cavity [1,2,13]. In addition, CT can help in surgical planning by demonstrating erosions of ossicles or other inner ear structures (such as perilymphatic fistulae) caused by such masses [14]. Given the surrounding dense bone, IV contrast is usually not beneficial in studying enhancement characteristics of middle ear masses. However, contrast enhancement may help delineate extraosseous soft tissue associated with invasive neoplasms. CT Head There is no evidence to support use of CT head for assessment of patients with conductive hearing loss and middle ear mass identified on otoscopy. CTA Head There is no definite evidence to support use of CTA as a first-line modality for assessment of patients with conductive hearing loss and middle ear mass identified on otoscopy. However, in patients with high clinical suspicion of middle ear paraganglioma, CTA is sometimes used initially for diagnostic confirmation and for planning further management. MRI Head and Internal Auditory Canal Extent of a middle ear cavity mass identified on otoscopy in a patient with conductive hearing loss is much better defined using MRI obtained without and with IV contrast [2,5,13,15]. This assessment is better done using thin sections across the temporal bone as part of a dedicated internal auditory canal (IAC) protocol rather than a routine brain MRI. Excellent soft-tissue contrast afforded by even a noncontrast MRI often complements the bony details seen on temporal bone CT for complete evaluation of such patients prior to surgical intervention. MRA Head MRA is usually not used as a first-line imaging modality in patients presenting with conductive hearing loss.