R Labadie

Publications of R Labadie

• Automatic segmentation of intracochlear anatomy in conventional CT.

  Authors: Jack H Noble, Robert F Labadie, Omid Majdani, Benoit M Dawant

  IEEE transactions on bio-medical engineering. 06/2011; 58(9):2625-32.

  Cochlear implant surgery is a procedure performed to treat profound hearing loss. Clinical results suggest that implanting the electrode in the scala tympani, one of the two principal cavities insideCochlear implant surgery is a procedure performed to treat profound hearing loss. Clinical results suggest that implanting the electrode in the scala tympani, one of the two principal cavities inside the cochlea, may result in better hearing restoration. Segmentation of intracochlear cavities could thus aid the surgeon to choose the point of entry and angle of approach that maximize the likelihood of successful implant insertion, which may lead to more substantial hearing restoration. However, because the membrane that separates the intracochlear cavities is too thin to be seen in conventional in vivo imaging, traditional segmentation techniques are inadequate. In this paper, we circumvent this problem by creating an active shape model with micro CT (μCT) scans of the cochlea acquired ex vivo. We then use this model to segment conventional CT scans. The model is fitted to the partial information available in the conventional scans and used to estimate the position of structures not visible in these images. Quantitative evaluation of our method, made possible by the set of μCTs, results in Dice similarity coefficients averaging 0.75. Mean and maximum surface errors average 0.21 and 0.80  mm.

• Temporal Bone Imaging: Comparison of Flat Panel Volume CT and Multisection CT.

  Authors: O Majdani, K Thews, S Bartling, M Leinung, C Dalchow, R Labadie, T Lenarz, G Heidrich

  AJNR. American journal of neuroradiology. 05/2009;

  BACKGROUND AND PURPOSE: A recent development in radiology is the use of flat panel detectors in CT to obtain higher-resolution images. This technique is known as flat panel volume CT (fpVCT). WeBACKGROUND AND PURPOSE: A recent development in radiology is the use of flat panel detectors in CT to obtain higher-resolution images. This technique is known as flat panel volume CT (fpVCT). We sought to compare the image quality and diagnostic value of 2 different flat panel detector-equipped scanners: one is a prototype fpVCT scanner, and the other is a so-called flat panel digital volume tomography (fpDVT) scanner, which is routinely used in clinical setup with current state-of-the-art multisection CT (MSCT) scanners. MATERIALS AND METHODS: Five explanted temporal bones and 2 whole-head cadaveric specimens were scanned with fpVCT, fpDVT, and MSCT scanners. The image series were blindly evaluated by 3 trained observers who rated 38 anatomic structures with regard to their delineation/appearance. RESULTS: Although the image quality obtained with fpVCT and fpDVT was rated significantly better compared with MSCT on isolated temporal bones, the differences were not significant when whole cadaveric heads were scanned. CONCLUSIONS: Theoretic and practical advantages exist for flat panel detector-equipped scanners, including improved image quality. However, when imaging whole cadaveric heads, no significant difference could be demonstrated between them and standard-of-care MSCT.