SHINJI NAGANAWA, MD, PHD Department of Radiology Nagoya University Graduate School of Medicine Nagoya, Japan TSUTOMU NAKASHIMA, MD, PHD Department of Otorhinolaryngology Nagoya University Graduate School of Medicine Nagoya, Japan BIBLIOGRAPHY 1. Carfrae MJ, Holtzman A, Eames F, Parnes SM, Lupinetti A. 3 Tesla delayed contrast magnetic resonance imaging evalua- tion of Meniere’s disease. Laryngoscope 2008;118:501–505. 2. Naganawa S, Komada T, Fukatsu H, Ishigaki T, Takizawa O. Observation of contrast enhancement in the cochlear fluid space of healthy subjects using a 3D-FLAIR sequence at 3 Tesla. Eur Radiol 2006;16:733–737. 3. Nakashima T, Naganawa S, Sugiura M, et al. Visualization of endolymphatic hydrops in patients with Meniere’s disease. Laryngoscope 2007;117:415–20. In Reply: We thank Drs. Naganawa and Nakashima for their interest in our article. We agree that use of a phantom would have been useful in standardizing our data regard- ing perilymphatic gadolinium contrast enhancement in normal subjects. Although, our pre- and postcontrast ac- quisition parameters were identical, thus our regions of interest measurements remain valid. We apologize for omitting reference to Dr. Naganawa’s publication on the diffusion of contrast in the cochleas of normal human subjects. 1 However, it is encouraging that our finding of maximal cochlear contrast enhancement at 4 hours corre- sponds with their results. Additionally, our results were in line with previous mammalian animal studies as detailed in our article. We used T1-weighted fast gradient echo images as stated in the article. However, the low flip angle, short repetition time and echo time, and lack of refocusing pulse do alter some of the expected imaging characteristics. As stated, the contrast enhancement in the cochlea was mod- est but significant. This was expected given the limita- tions on intravenous contrast load in humans, and was consistent with previous animal studies. Our discussion pointed to the need to increase contrast concentration in the inner ear, or magnetic field strength to further delin- eate the intracochlear fluid spaces. Drs. Naganawa’s and Nakashima’s recent publication 2 uses a novel approach of intratympanic gadolinium-based contrast administration, successfully increasing the concentration of contrast in the inner ear, and resulting in successful delineation of the intracochlear fluid spaces. MATTHEW CARFRAE, MD University of Virginia Charlottesville, Virginia BIBLIOGRAPHY 1. Naganawa S, Komada T, Fukatsu H, Ishigaki T, Takizawa O. Observation of contrast enhancement in the cochlear fluid space of healthy subjects using a 3D-FLAIR sequence at 3 Tesla. Eur Radiol 2006;16:733–737. 2. Nakashima T, Naganawa S, Sugiura M, et al. Visualization of endolymphatic hydrops in patients with Meniere’s disease. Laryngoscope 2007;117:415– 420. In reference to Cochleovestibular Anomalies in Children With Cholesteatoma Dear Editor: New findings of differences in anatomy of inner ear in patients with cholesteatoma are fittingly described in the article by Propst et al. 1 titled “Cochleovestibular Anoma- lies in Children With Cholesteatoma.” There is a problem in this article that must be mentioned. The authors showed some differences in anatomy of inner ear of pa- tients with cholesteatoma comparing with normal ones by use of temporal bone CT scans. They incited that a gradi- ent in prevalence of these findings being most common in the congenital cholesteatoma group, intermediate in the acquired cholesteatoma group, and least common in con- trols. They concluded that “The gradient in prevalence of these findings may suggest a relationship between con- genital and acquired cholesteatoma. These may include a generalized temporal bone anomaly that predisposes to cholesteatoma formation, or a third variable such as ge- netic mutation may predispose to both anomalous cochleo- vestibular formation and cholesteatoma.” On the other hand, in the Results section they also noted that there were no differences in measurements between ears with cholesteatoma and contralateral disease-free temporal bones. Here, we could ask a question. If the anomaly is present in both ears of each patient, why one ear harbors the cholesteatoma and the other one is disease-free? These anomalies were more prevalent in patients with congeni- tal cholesteatomas, but if we review the literature we can find that bilateral congenital cholesteatomas is an ex- tremely rare entity. 2–4 So, why the other ear remains disease-free? In the acquired type of the cholesteatoma the literature shows a range of 4.4% to 17% for the incidence of bilateral cholesteatoma. 5–8 Again, why the contralat- eral ear with the same inner ear anomalies remains free of the cholesteatoma in the majority of the patients? The control group of the authors was chosen from the patients who had trauma and petrous CT studies. In gen- eral, we do not need precise view of the inner ear anatomy in these patients, and the status of the fallopian canal is our main aim of the CT in these patients. So, in these two study groups, it may be the differences in techniques of obtaining the CT images that have resulted in the Propst et al. findings. ALI EFTEKHARIAN, MD Department of Otolaryngology Head and Neck Surgery Loghman Hospital Tehran, Iran Editor’s Note: Dr. Evan Jon Propst has indicated he agrees this is an interesting question for which he has no answer. Laryngoscope 118: October 2008 Letters to the Editor 1905