In the diagnosis of cholesteatoma, non-echo-planar diffusion-weighted MRI using the PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) technique has been reported to be useful. However, interpretation of positive findings is subjective and the decision criteria remain unclear. It is necessary to establish an objective standard for evaluation of the signal intensity.
　The aim of this study was to establish whether diffusion MRI using the PROPELLER technique is effective for the diagnosis of cholesteatoma. Furthermore, we investigated whether objective evaluation is possible by comparing the signal intensities and determining which region of brain is the most suitable for such comparison.
　We evaluated 35 ears with a postoperative diagnosis of cholesteatoma for which preoperative evaluation had been performed by MRI using the PROPRLLER technique. We determined a lesion as positive if it showed a higher intensity than the cerebellar white matter. Furthermore, for objective evaluation, we set regions of interest and compared the highest signal intensity of the target lesion with that of the following parts of the brain; cerebellum, cerebellar white matter, temporal lobe, temporal lobe white matter.
　The sensitivity/positive-predictive value were 85.7%, and the specificity/negative-predictive value was 42.9%. The smallest lesion observed was 3.8 mm in diameter. In addition, in 4 of the 35 ears, no lesion could be detected. Objective evaluation by comparison of the highest signal intensities of the regions of interest matched with the diagnosis after surgery in 26 of the 31 ears. The findings suggested that the cerebellar white matter was the most suitable among the 4 regions evaluated for such comparison.
　This method is thought to be useful, especially in cases where macroscopic evaluation of the lesions is difficult.

　Orbital infection often disturbs the functioning of the eyes because of the increase of the orbital pressure caused by the inflammatory reaction and abscess formation. Herein, we report the case of a 68-year-old woman who developed an intraorbital abscess as a complication of acute dacryocystitis while receiving methotrexate therapy. We performed endonasal endoscopic drainage of the intraorbital abscess and didn't find orbital complications. In such cases, it is necessary to establish quick and close cooperation with ophthalmologists and perform urgent surgical drainage to preserve the functioning of the eyes.

　In general, patients with recent versions of cochlear implants (CIs) can safely undergo Magnetic Resonance Imaging (MRI) within 1.5 T scanners, without the need of inner magnet removal surgery. However, even if they wear tight head bandages on their inner coil, complications can occur in CI users during MRI, such as pain, skin reaction, demagnetization of the internal magnet, and dislocation of the magnet out of its silicon flange.
　We encountered two cases of reversal of the inner magnet of a CI during MRI examination. In both cases, the inner magnets were reversed by 180 degrees, although they remained in the silicon flange. We ordered a polar-changed extra magnet for replacing the reversed inner magnet in one case, and performed a re-implant surgery of the inner magnet in the other.
　In recent years, the number of hearing-impaired patients with CIs has been increasing along with expansion of the medical indications for CI in the rapidly aging population of the developed countries. On the other hand, MRI is an indispensable clinical diagnostic tool in modern medical practice. Physicians and paramedics must be aware of possible complications that can occur during MRI in patients with CIs. Prompt assessment and appropriate treatment are important in patients with CIs developing complications during MRI examination.

　Medical education of doctors who are not specialists in vestibular disorders on the diagnosis and treatment of benign paroxysmal positional vertigo (BPPV) by supervisory doctors is essential for their proper diagnosis and treatment of BPPV in daily clinical practice. In this study, we gave lectures about BPPV to three doctors who were not specialists in vestibular disorders, and checked their medical examinations of patients with BPPV. We advised them to conduct the positional nystagmus (PN) test more than twice when there was a possibility of BPPV and they could not appreciate benign paroxysmal PN. Following this practice, they could appreciate the PN after repeating the test a second time and successfully diagnose BPPV. When they could see PN during the reverse Dix-Hallpike maneuver, but not during the Dix-Hallpike maneuver, they suspected BPPV, but could not diagnose the subtype of BPPV. When they saw downward PN during the Dix-Hallpike maneuver, they misdiagnosed affected side. Supervisory doctors have to instruct doctors who are not specialists in vestibular disorders on the characteristics of the typical PN seen in patients with BPPV, and have to check not only the clinical reports of these doctors, but also the movies of PN recorded by them.