In vivo Assessment of an Endolymphatic Hydrops Gradient Along the Cochlea in Patients With Menière's Disease by Magnetic Resonance Imaging-A Pilot Study.

OBJECTIVE: To assess three strategies for evaluation and description of potential endolymphatic hydrops (EH) gradients along the cochlea in patients with Menière's disease. STUDY DESIGN: Prospective observational study. METHODS: Ten patients with definite Menière's disease revealed by magnetic resonance imaging were included in this prospectively conducted pilot study. The presence of cochlear endolymphatic hydrops as well as a potential hydrops gradient along the cochlea were subjectively evaluated by two readers. Furthermore, both readers performed planimetric measurements of the relative extent of endolymphatic hydrops in the cochlear turns for calculation of an apico-basal-index (ABI) and an average gradient slope of the endolymphatic hydrops. These models were correlated with the available pure tone audiometry (PTA). RESULTS: Qualitatively, 13 of 16 inner ears presented an apical EH distribution. The median ABI was 1.69 for patients with low-tone hearing loss and 1.17 for patients with a flat PTA curve (p = 0.03). The median EH slope was 7.44 and correlated with the steepness of the PTA (ρ = 0.583; p = 0.018). The subjective analysis and the slope model were best fit for prediction of a low-tone hearing loss type with sensitivities of 100% (specificity, 42.86%) and 88.9% (specificity, 71.4%), respectively. The inter-reader agreement in all three approaches was considered substantial to perfect. CONCLUSION: The presented qualitative approach and the slope model represent reliable methods for the description of a potential EH gradient along the cochlea. Furthermore, the average EH steepness along the cochlea correlates with the type of hearing loss.

Dual-energy CT: virtual calcium subtraction for assessment of bone marrow involvement of the spine in multiple myeloma.

OBJECTIVE. Dual-energy CT (DECT) enables subtraction of calcium, facilitating the visualization of bone marrow (BM) in the axial skeleton. The purpose of this study was to assess whether DECT BM images have the potential to improve the detection of multifocal and diffuse BM infiltration in multiple myeloma (MM) in comparison with regular CT with MRI as the reference standard. SUBJECTS AND METHODS. This study included 32 consecutive patients who had known MM or presented with monoclonal gammopathy of unknown significance and underwent DECT and MRI of the axial skeleton. The degrees (none, n = 14; moderate, n = 10; and high, n = 8) and patterns (diffuse, n = 10 or multifocal, n = 8) of infiltration were assessed on MR images. Attenuation in BM and CT images in known uninvolved and involved areas was measured. Cutoff values of attenuation in BM images for infiltration in lytic and nonlytic lesions were established by ROC analysis. At least 120 days later, sensitivity and specificity for reading CT images alone and when using additional BM images were evaluated. RESULTS. ROC analysis revealed larger AUC in BM images than in CT images; cutoff values for marrow invasion in BM images were 4 and -3 HU in lytic and nonlytic lesions, respectively. In the blinded reading session, BM images improved the sensitivity for the detection of diffuse infiltration from 0 to as much as 75% for cases with high-grade infiltration. In multifocal patterns, BM images did not significantly change the detection rate. CONCLUSION. BM images have the potential to improve the sensitivity for detection of diffuse BM involvement in comparison with regular CT.