Is CT Still the Gold Standard in Semicircular Canal Dehiscence? Diagnostic Value of MRI in Poschl and Stenver Planes.

BACKGROUND/

OBJECTIVES

The primary aim of this study was to investigate whether magnetic resonance imaging (MRI) of the superior and posterior semicircular canals (SCs) in cases with and without dehiscence gives results similar to those of CT. As a novel contribution, the secondary aim was to assess the diagnostic correlation between CT and MRI sequences obtained primarily in Poschl and Stenver planes, instead of reformatted images, for detecting superior and posterior semicircular canal dehiscence.

METHODS

A total of 103 patients were retrospectively evaluated based on CT scans, and 27 of them, with the appearance or suspicion of at least one SCD and/or thinner-than-normal canal roof bone, were prospectively examined with MRI.

RESULTS

With CT as a reference, MRI had a 78% detection rate and 92% specificity for the detection of dehiscence in the superior SCs. For posterior SCs, the dehiscence detection rate and specificity of MRI were 70% and 97%, respectively. CT and MRI examinations showed a significant agreement in the diagnosis of SCD (κ = 0.71, p < 0.001 for superior SCD; κ = 0.73, p < 0.001 for posterior SCD). The agreement values of MRIs obtained in Poschl and Stenver planes with CT in the detection of dehiscence were calculated as κ = 0.43 in Poschl and κ = 0.51 in Stenver for superior SCD; κ = 0.45 in Poschl and κ = 0.46 in Stenver for posterior SCD.

CONCLUSIONS

The MRI results demonstrated similar diagnostic precision to CT when identifying SCD. In patients presenting with vertigo, nystagmus, and hearing loss, normal MRI findings may be sufficient to exclude semicircular canal dehiscence (SCD), thereby potentially obviating the need for additional CT imaging. The newly introduced Poschl and Stenver plane MRI sequences demonstrate a moderate relationship with CT for SCD diagnosis.