Neuroimaging in patients referred to a neuro-ophthalmology service: the rates of appropriateness and concordance in interpretation

Abstract

Objective: Neuroimaging studies frequently are ordered to investigate neuro-ophthalmic symptoms. When misused, these studies are expensive and time consuming. This study describes the type and frequency of neuroimaging errors in patients referred to an academic neuro-ophthalmology service and measures how frequently these neuroimaging studies were reinterpreted.

Design: Prospective cohort study.

Participants: Eighty-four consecutive patients referred to an academic neuro-ophthalmology practice.

Methods: From November 2009 through July 2010, 84 consecutive new patients who had undergone a neuroimaging study in the last 12 months specifically to evaluate their presenting neuro-ophthalmic symptoms were enrolled prospectively. Participants then underwent a complete neuro-ophthalmic evaluation, followed by a review of prior neuroimaging. Questions regarding appropriateness of the most recent imaging, concordance of radiologic interpretation, and re-evaluation of referring diagnoses were answered by the attending physician.

Main outcome measures: The frequency and types of errors committed in the use of neuroimaging and the frequency of reinterpretation of prereferral neuroimaging studies after neuro-ophthalmic history and examination.

Results: Most study participants (84.5%; 71/84) underwent magnetic resonance imaging before referral; 15.5% (13/84) underwent only computed tomography. The rate of suboptimal neuroimaging studies was 38.1% (32/84). The 3 most common reasons for suboptimal studies were incomplete area of imaging (34.4%; 11/32), wrong study type (28.1%; 9/32), and poor image quality (21.9%; 7/32). Twenty-four of 84 subjects (28.6%) required additional neuroimaging. The authors agreed with the radiology interpretation of the prior neuroimaging studies in most patients (77.4%; 65/84). The most common anatomic locations for discordance in interpretation were the intraorbital optic nerve (35%; 7/20) and the brainstem (20%; 4/20).

Conclusions: There was a high rate of suboptimal neuroimaging studies performed in patients referred for neuro-ophthalmology examination. These findings have significant implications given the increasing attention to resource use currently and in the near future.