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Manabu Kinoshita, Hideyuki Arita, Yoshiko Okita, Naoki Kagawa, Haruhiko Kishima, Naoya Hashimoto, Hisashi Tanaka, Yoshiyuki Watanabe, Eku Shimosegawa, Jun Hatazawa, Yasunori Fujimoto and Toshiki Yoshimine

were stereotactically obtained during image guidance with presurgical ADC and fractional anisotropy (FA) maps calculated following diffusion tensor imaging (DTI). The investigation was further extended to compare DTI and metabolic imaging with 11 C-methionine (MET) PET regarding the magnitude of the correlation between imaging and cell density to identify the most reliable imaging modality to evaluate glioma tissue characteristics. Methods Patient Selection This study was approved by the local ethics committee and was found to conform to generally accepted

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Przemysław A. Pękala, Brandon M. Henry, Jakub R. Pękala, Wan Chin Hsieh, Jens Vikse, Beatrice Sanna, Jerzy A. Walocha, R. Shane Tubbs and Krzysztof A. Tomaszewski

F oramen arcuale (FA) is an osseous prominence formed in place of a sulcus for the vertebral artery on the posterior arch of the atlas ( Fig. 1 ). It is an anatomical variant, and when present, the FA partially or completely encircles the suboccipital nerve, vertebral venous plexus, and V 3 segment of vertebral artery as it exits the transverse foramen. 118 Fig. 1. Representative examples of the complete FA as demonstrated by cadaveric dissection ( A ), a lateral radiograph ( B ), and a 3D CT reconstruction ( C ). Figure is available in color online only. The

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Ellen L. Air, Weihong Yuan, Scott K. Holland, Blaise V. Jones, Karin Bierbrauer, Mekibib Altaye and Francesco T. Mangano

. Fractional anisotropy is a commonly used DT imaging parameter that measures the uniformity of the direction of water diffusion and is expressed from 0 to 1. The FA value rapidly increases from birth through 24 months of life, during the period of postnatal myelination, then slowly plateaus and remains steady after 5 years of age. 4 , 8 , 12 , 25 Few studies have used DT imaging to evaluate white matter changes in young children with hydrocephalus and the potential impact of shunt insertion. We previously reported that FA values in infants with newly diagnosed

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Hiroshi Kashimura, Takashi Inoue, Kuniaki Ogasawara, Hiroshi Arai, Yasunari Otawara, Yoshiyuki Kanbara and Akira Ogawa

DT imaging, including FA, relative anisotropy, and volume ratio. The FA can precisely measure the degree of deviation from isotropic diffusion 1–3 , 5 , 9 , 11 , 15 , 16 , 20 , 21 and provides the best performance in terms of contrast-to-noise ratio as a function of signal-to-noise ratio in simulations. 14 , 18 The FA is expressed as a numerical value between 0 and 1 without a unit; 0 corresponds to unrestricted isotropic diffusion of water and 1 corresponds to linear anisotropic diffusion. It is influenced by histological findings such as the content of fibrous

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Hussam Metwali, Mario Giordano, Katja Kniese and Rudolf Fahlbusch

(DTI) can improve the visualization of the optic pathways. Besides the possibility of reconstruction of the visual pathways via fiber tracking, DTI can provide further useful measurements like fractional anisotropy (FA), which can be considered as an index of the integrity of the optic pathway. It has been found that the FA of the optic pathways could be affected in diverse ophthalmological conditions. 8 , 9 , 25 Furthermore, changes in the FA have also been found to be related to different diseases of the CNS, their progression, and their response to treatment. 4

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Saman Shabani, Mayank Kaushal, Matthew Budde and Shekar N. Kurpad

structural alterations remote from the site of injury in the form of changes to DTI indices. 6 , 11 , 15 , 27 , 34 , 35 One such DTI parameter, fractional anisotropy (FA), measuring the degree of diffusion anisotropy or restricted diffusion, is often correlated with injury severity and/or neurological outcomes. Previously, our group reported an association between FA value estimated at the high cervical cord (C1–2) during the acute phase of SCI and American Spinal Injury Association (ASIA) grades at admission, which showed the utility of DTI in early detection of

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Satoru Osuka, Akira Matsushita, Tetsuya Yamamoto, Kousaku Saotome, Tomonori Isobe, Yasushi Nagatomo, Tomohiko Masumoto, Yoji Komatsu, Eiichi Ishikawa and Akira Matsumura

hydrocephalus is still controversial. 8 , 20 There has been considerable interest in developing more sensitive and less invasive physiological diagnostic techniques. Diffusion tensor imaging is a relatively new MR imaging technique that makes use of diffusion-sensitizing gradients applied in 6 or more noncollinear directions to determine the full DT. 2 This imaging modality can extract the principle diffusivities, the MD, and the FA. These diffusion data provide microstructure information about white matter that cannot be evaluated using conventional MR imaging

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Vibhor Krishna, Francesco Sammartino, Philip Yee, David Mikulis, Matthew Walker, Gavin Elias and Mojgan Hodaie

of the neuronal microstructural integrity. 13 Fractional anisotropy (FA) is a composite measure of magnitude and directionality of diffusion restriction. FA can vary between 0 and 1; the white matter is typically more than 0.2, whereas the gray matter is less than 0.2. 19 An external compression on the brain would initially increase anisotropy due to diffusion restriction in the direction perpendicular to the compression. However, prolonged or severe compression may cause irreversible injury (e.g., edema, hemorrhage, demyelination, or axonal loss) and an

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Makoto Ideguchi, Koji Kajiwara, Koichi Yoshikawa, Hisaharu Goto, Kazutaka Sugimoto, Takao Inoue, Sadahiro Nomura and Michiyasu Suzuki

principles underlying the classification of an artery in the resection area. Lesion borders were defined using a neuronavigation system (StealthStation S7; Medtronic Inc.). Three types of artery were defined: a feeding artery (FA) that fed the resection area only; a “passing through” artery (PA) that did not feed the resection area but perfused the surrounding normal area; and a combined FA+PA artery that possessed the features of an FA and PA ( Fig. 1A ). A lesion-related FA+PA artery passes through the resection planning area, but when the branching small arteries from

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Satoru Osuka, Akira Matsushita, Eiichi Ishikawa, Kousaku Saotome, Tetsuya Yamamoto, Aiki Marushima, Naoaki Satou, Alexander Zaboronok, Tomohiko Masumoto and Akira Matsumura

of brain compression efficiently, but can evaluate only the total pressure inside the skull. Diffusion tensor imaging is a novel MRI technique that can provide information on the microstructural properties of white matter. Diffusion tensor imaging makes use of diffusion-sensitizing gradients applied in 6 or more noncollinear directions to determine the full diffusion tensor. 3 Diffusion tensor imaging can extract the principal diffusivities, the mean diffusivity, and the FA. These diffusion data provide information about the white matter microstructure that