Table 1.
Semi-quantitative (SQ) grading conventions at a glance.
| Nakashima et al. (19) | Gürkov et al. (24) Yang et al. (25) | Baráth et al. (20) | Attyé et al. (81) | Kirsch et al. (22) Boegle et al. (present data) | Bernaerts et al. (21) Bernaerts and de Foer (23) | |
|---|---|---|---|---|---|---|
| COCHLEA | ||||||
| Slice of evaluation | Midmodiolar level | Not specified | Midmodiolar level | Same as Nakashima et al. (19) | Midmodiolar level | Midmodiolar level |
| Grade 0 | No displacement of RM, interscalar septum, scala tympani, cochlear duct, scala vestibuli visible | No enlargement of ELS, PLS is clearly visible | No displacement of RM, interscalar septum, scala tympani, cochlear duct, scala vestibuli visible | “X-mas tree” made of circles with “very thin, clear, hypointense line” (cp. Figure 1A). | “Very thin, clear, hypointense line” (=non-enhancing scala media or ELS) between clearly enhancing scala vestibuli and scala tympani (=PLS) | |
| Grade 1 | Displacement of RM, cochlear duct < scala vestibuli | ELS is enlarged and bulging into PLS | Irregular dilation and partial obstruction of the scala vestibuli, cochlear duct indirectly visible as nocular black cut-out of the scala vestibuli | “X-mas tree” with “X-mas lights”, where ELS is slightly enlarged and indirectly visible as a nodular black cut out (cp. Figure 1B). | “X-mas tree” (=enhancing scala vestibuli and scala tympani) with “X-mas balls” (=nodular enlargement non-enhancing scala media) | |
| Grade 2 | Displacement of RM, cochlear duct > scala vestibuli | Scala media is scalloping into the scala tympani, PLS has a semicircular appearance | “X-mas tree” with “X-mas balls”, where ELS is bulding into scala tympani whilst giving the PLS a semicircular appearance (cp. Figure 1C). | |||
| Grade 3 | A severely distended scala media causes a flattened appearance of the perilymph space | No scala vestibuli visible | “X-mas tree” with “X-mas garlands”, where ELS is distended and causes a flattened appearance of the PLS (cp. Figure 1D). | “X-mas tree” (=enhancing scala vestibuli and scala tympani) with “X-mas garlands” (=linear enlarged non-enhancing scala media) | ||
| VESTIBULUM | ||||||
| Slice of evaluation | Lowest slice of vestibulum L-SCC still visible | Same as Nakashima et al. (19) | Midmodiolar level | Axial slice through inferior part of vestibulum | Vestibulum inferior part; L-SCC still visible | Vestibulum inferior part |
| Grade 0 | AR <33.3% | AR <50%, sacculus and utriculus are distinguishable | SURI <1, no saccular abnormality | Sacculus < utriculus, otoliths still distinguishable (cp. Figure 1A). | AR <50%,sacculus < utriculus, otoliths are distinguishable | |
| Grade 1 | 33.3% < AR <50% | SURI ≥1 | Sacculus (sign should remain as is) utriculus, otoliths are still distinguishable (cp. Figure 1B). | Sacculus ≥ utriculus, otoliths are distinguishable | ||
| Grade 2 | AR >50% | AR >50%, PLS remains visible with circular rim enhancement | No sacculus visible | Sacculus & utriculus are confluent, PLS rim visible (cp. Figure 1C). | Sacculus and utriculus are confluent, PLS remains visible with circular rim enhancement | |
| Grade 3 | No PLS visible | No otolith organs distinguishable, no PLS visible (cp. Figure 1D). | No PLS visible | |||
AR, area ratio; ELS, endolymphatic space; L-SCC, lateral semicircular canal; PLS, perilymphatic space; SURI, ratio ≥ 1 between the area of the sacculus and the area of the utriculus, RM, Reissner's membrane. The bold text highlights the main or most important characteristics.