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Paula Eboli, Bob Shafa and Marc Mayberg

iCT/EM navigation TSA group, a CereTom (Neurologica, Inc.) portable noncontrast head CT scanner was used in a preoperative room adjacent to the operating room (scan parameters: 140 kVp; 7 MA; 28000 MA; 1.25 × 1.25 [thickness by spacing]; 1900–2000 mGy-cm [dose length product]). The CT scans were then loaded into the AXIEM Stealth Station navigation system (SNT/Medtronic) while the patient was transferred to the operating room and prepared for general anesthesia. In the majority of cases, the iCT data were fused to preexisting patient MR images obtained at other

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Philipp Gölitz, Tobias Struffert, Oliver Ganslandt, Marc Saake, Hannes Lücking, Julie Rösch, Frauke Knossalla and Arnd Doerfler

dose index of a 3D DSA amounts to approximately 9 mGy, and the dose length product to 180 mGy × cm. 8 Preliminary internal data showed an effective dose for 3D DSA at a level of 1.2 mSV and that for a biplane DSA series at a level of 1 mSV. Reliable dose measurements for ivACT are not available, but referring to preliminary internal investigations, the effective dose should be at a level of about 1.5 mSv. Thus, especially in the follow-up of multiple clipped cerebral aneurysms, the use of ivACT could lessen the amount of radiation exposure to the patient compared

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Takahito Fujimori, Motoki Iwasaki, Yukitaka Nagamoto, Masafumi Kashii, Takahiro Ishii, Hironobu Sakaura, Kazuomi Sugamoto and Hideki Yoshikawa

their necks until they could rest their chin on their chest with the use of a supportive device in anterior flexion without pain or discomfort, and to have participants rotate their head perpendicular to the axis of their body trunk. To reduce radiation exposure, scans done in positions other than neutral were performed with a lower tube current: 15 mA for rotation and posterior flexion and 30 mA only for anterior flexion to reduce artifact of the jawbone. Total exposure was 90 dose-length products, which is less than that specified for routine CT scanning by our

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Jonathan Pindrik, Thierry A. G. M. Huisman, Mahadevappa Mahesh, Aylin Tekes and Edward S. Ahn

voltage (in kVp), tube current and scan time product (in mA/sec), volume CT dose index ([CTDIvol]; in mGy), and dose-length product ([DLP]; in mGy × cm). 11 The CTDIvol represents a fundamental dose indicator reflecting the radiation dose exposure for a given CT scanner and set of parameters (tube current and voltage). 11 Documentation of CTDIvol for most CT studies allows calculation of the DLP: [Eq. 1] The DLP represents the total amount of radiation dose delivered during a specific CT scan, accounting for scan length. 11 , 18 Similarly, the ED quantifies

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Tsuyoshi Sugiura, Yukitaka Nagamoto, Motoki Iwasaki, Masafumi Kashii, Takashi Kaito, Tsuyoshi Murase, Tetsuya Tomita, Hideki Yoshikawa and Kazuomi Sugamoto

used to keep the head at the correct rotation point ( Fig. 1 ). To reduce radiation exposure, scans done in positions other than neutral were performed with a lower tube current (15 mA). Total exposure was 60 dose-length products, which is less than that specified for routine CT by our hospital. CT data were transferred via a digital imaging and communications in medicine network into a computer workstation, where image processing was performed using Virtual Place software (M series, Medical Imaging Laboratory). F ig . 1. Computed tomography scans were

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Alexander G. Weil, John Ragheb, Toba N. Niazi and Sanjiv Bhatia

dose is clearly decreased in this study by the reduction in tube current (mA), the actual amount of ionizing radiation received with both standard and “reduced dose” CT is not known, because this depends on multiple other variables. Providing the weighted average CT dose index (CTDI W ) for a slice (mGy) and the dose-length product (DLP) for a complete CT scan (mGy-cm) at the given tube currents (mA) may give a better idea of how low a “low-dose” CT is at this institution in comparison to the standard pediatric dose ( http

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Xiaofeng Deng, Kai Wang, Liang Wu, Chenlong Yang, Tao Yang, Lei Zhao, Jun Yang, Guihuai Wang, Jingyi Fang and Yulun Xu

by the spinal DSA (dose surface product [DSP] expressed in micrograys per square meter [μGy.m 2 ]) with the dose delivered by the 3D CTA (dose length product [DLP] expressed in milligrays per centimeter [mGy.cm]), we converted DSP and DLP into effective dose (E) (expressed in millisieverts [mSv]) by using the following formulae 3 : Effective dose (mSv) = DLP (mGy.cm) × k (mSv/mGy.cm) (k = generalized E/DLP coefficient, ≈0.015 for thoracoabdominal acquisition) Effective dose (mSv) = DSP (μGy.m 2 ) × 10 −2 × k (mSv/μGy. m 2 ) (k = generalized E

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Yukitaka Nagamoto, Motoki Iwasaki, Tsuyoshi Sugiura, Takahito Fujimori, Yohei Matsuo, Masafumi Kashii, Hironobu Sakaura, Takahiro Ishii, Tsuyoshi Murase, Hideki Yoshikawa and Kazuomi Sugamoto

lower tube current: 15 mA for rotation and extension and 30 mA only for flexion. Total exposure was 90 dose–length products, which is less than that specified for routine CT by our hospital, and CT data were transferred via a DICOM network into a computer workstation, where image processing was performed using Virtual Place software (M series, Medical Imaging Laboratory). F ig . 2. Photographs and representative scans showing the 5 positions used for CT. Two types of supportive devices were used: one designed to facilitate production of the same 45° head

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Francesco Costa, Alessandro Ortolina, Luca Attuati, Andrea Cardia, Massimo Tomei, Marco Riva, Luca Balzarini and Maurizio Fornari

acquired before surgery to verify the correct alignment of the fracture reduction, and in 1 case CT scans were obtained to verify the accuracy of a repositioned screw. The intraoperative radiation exposure, in following our cervical protocol, was as follows: 120 kVp, 25 mA, 97.75 mAs, and 12.41 CT dose index, while the dose-length product ranged from 85.4 to 198.55, according to the collimation used, which corresponded to a mean of 0.78 mSv (range 0.5–1.1 mSv) for each patient for each CT acquisition. The mean surgical radiation dose received by the patient was 1

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Vijay M. Ravindra, Jay Riva-Cambrin, Walavan Sivakumar, Ryan R. Metzger and Robert J. Bollo

of injury to the internal carotid artery (ICA) or vertebral artery (VA), type of brain injury (that is, epidural, subdural, or subarachnoid hemorrhage), presence of hypodensity on images consistent with ischemia, Rotterdam score (a 6-point score, based on findings on initial noncontrast CT, that predicts the mortality rate at 6 months postinjury in moderate and severe TBI and has been validated in the pediatric population), 18 , 19 and radiation dose delivered to the patient measured in dose-length product. The primary outcome was ICA or VA injury identified by