The role of MRI in suspected inner ear malformations

Purpose: This is a prospective analysis of the value of MRI in suspected inner ear malformations. Materials and Methods: In 50 patients (43 children and young adults, 7 adults) with suspected inner ear malformation MRI (1.5 T) was performed. In addition, 42 of these patients underwent CT. For the analysis of the inner ear structures, the constructive interference in steady state (CISS) sequence with 0.7 mm slice thickness was used. Functional tests revealed a sensorineural hearing loss or deafness in 82 temporal bones (TB) and a combined hearing loss in 4 TB. The hearing loss was unilateral in 14 patients. MRI and CT findings were compared. Results: Imaging findings were normal in 58 TB. The pathological findings included inner ear malformations (35 TB), inflammatory changes (4 TB), partial obliteration of labyrinth (2 TB) and congenital aural atresia (1 TB). An isolated absence of the cochlear nerve (1 TB) could only be found by MRI. In the remaining cases, an inner ear malformation was diagnosed by MRI and CT with the same confidence but MRI was superior in displaying the fine details. Conclusions: MRI will become the method of choice in the diagnosis of inner ear malformations. (orig.)