Fast spin Echo Magnetic Resonance Imaging: Clinical Application in Screening for Acoustic Neuroma

Cost-effective diagnosis of acoustic neuromas: a philosophical, macroeconomic, and technological decision

OBJECTIVE

Our goals were to define the most sensitive techniques of acoustic neuroma diagnosis, to examine their relative costs, and to propose diagnostic modality selection given the rarity of acoustic neuroma incidence and given the other costs that society faces in more commonly encountered diseases.

METHODS

We conducted a MEDLINE search of the English language from 1966 to 2001 using the following keywords: acoustic neuroma, acoustic tumor, vestibular schwannoma, diagnosis, cost effectiveness, MRI, auditory brainstem response, brainstem audiometric evoked response, incidence, and prevalence.

RESULTS

Although magnetic resonance imaging with gadolinium remains the most sensitive diagnostic modality in the discovery of acoustic neuromas, its cost may be prohibitive for some societies.

CONCLUSION

Which modality to use in acoustic neuroma diagnosis is just as much a philosophical and macroeconomic question as a technological one.

CLINICAL SIGNIFICANCE

The cost of a timely diagnosis of acoustic neuromas must be weighed against using resources for other, more pressing, health concerns.

Magnetic resonance imaging in the search for retrocochlear pathology

OBJECTIVES

The purpose of this study is to evaluate the incidence of retrocochlear pathologic conditions that may be seen with full, contrast-enhanced magnetic resonance imaging of the brain, relative to more limited studies of the internal auditory canals (IACs) in patients with unilateral hearing loss or tinnitus with or without dizziness.

METHODS

A retrospective study was performed on all patients who had a magnetic resonance imaging of the brain and otologic symptoms over a 7-year period.

RESULTS

Abnormalities were found in 11 of 128 patients with only auditory symptoms and in 63 of 282 patients with auditory symptoms and/or dizziness (P = 0.005). Treatable lesions may not have been identified with a limited IAC study in 3 of 128 patients with only unilateral auditory symptoms, and 21 of 282 patients with dizziness (P = 0.045).

CONCLUSIONS

Limited MRI of the IACs may serve as an adequate screening test for retrocochlear pathologic conditions in patients with unilateral auditory symptoms and no dizziness.

Ultra high resolution nonenhanced fast spin echo magnetic resonance imaging: cost-effective screening for acoustic neuroma in patients with sudden sensorineural hearing loss

The financial burden for the evaluation of patients for acoustic neuroma in an otolaryngology practice is substantial. Patients with sudden sensorineural hearing loss represent a portion of that population seen with unilateral, asymmetric auditory symptoms who require investigation for acoustic neuroma. For these patients, gadolinium-enhanced magnetic resonance imaging is the diagnostic gold standard. Auditory brain stem response testing has been used in the past as a screening test for acoustic neuroma, but its apparent sensitivity has fallen as the ability to image smaller acoustic neuromas has improved. Fast spin echo magnetic resonance imaging techniques without gadolinium have been shown to be as effective in the detection of acoustic neuroma as contrast-enhanced magnetic resonance imaging. Limited nonenhanced fast spin echo magnetic resonance imaging now provides an inexpensive alternative for high-resolution imaging of the internal auditory canal and cerebellopontine angle. Fast spin echo magnetic resonance imaging can now be done at a cost approximating auditory brain stem response testing while providing the anatomic information of contrast-enhanced magnetic resonance imaging. Cost analysis was done in the cases of 58 patients with sudden sensorineural hearing loss by comparing the costs for routine workup and screening of acoustic neuroma with the cost of fast spin echo magnetic resonance imaging with the use of screening protocols based on literature review. The potential cost savings of evaluating patients with sudden sensorineural hearing loss with fast spin echo magnetic resonance imaging for acoustic neuroma was substantial, with a 54% reduction in screening costs. In an era of medical economic scrutiny, fast spin echo magnetic resonance imaging has become the most cost-effective method to screen suspected cases of acoustic tumors at our institution by improving existing technology while reducing the cost of providing that technology and eliminating charges for impedance audiometry, auditory brain stem response testing, and contrast-enhanced magnetic resonance imaging.