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Principles of Radiation Detection and Image Formation
Published in Ken Holmes, Marcus Elkington, Phil Harris, Clark's Essential Physics in Imaging for Radiographers, 2021
For these reasons, CCD using an image intensifier became the dominant system and this type of technology is still widespread in clinical use. Even so, there are some issues: it requires a large housing and its image is distorted to some degree by the signal amplification that takes place inside the image intensifier. As a result of these inherent limitations, this technology is now being replaced by the flat panel technologies.
Radiation Safety for You and Your Patient
Published in Vikram S. Kashyap, Matthew Janko, Justin A. Smith, Endovascular Tools & Techniques Made Easy, 2020
George K. Zhou, Justin A. Smith, Benjamin Colvard
Larger image intensifiers can help generate the same image quality using less radiation. A collimator should also be used to focus the beam, which would both decrease leakage radiation and enhance image resolution. Collimators are composed of lead (or some other radiopaque material) shutters that can be adjusted to frame the region of interest to image and direct photons only to the area of interest; this focused beam then reduces radiation exposure to surrounding tissues.
Personnel Radiation Protection
Published in Robert J. Parelli, Principles of Fluoroscopic Image Intensification and Television Systems, 2020
The operator of the image intensifier should observe the following precautions when he/she is required to remain in the room during the exposure:Stand as far as practicable from the source of scattered radiation (patient).Wear protective aprons of at least 0.25 mm lead equivalent (preferably 0.50 mm) while in the room, if the exposure is likely to be to 5 mR/hr. or more.Monitor the x-ray tube current and potential in the AEC mode at least once each week with a designated phantom during use to ascertain that they are in normal range and keep weekly logs.Wear personnel monitoring devices at the shoulder or collar outside the apron.Make sure that a bucky slot cover and protective curtain are provided (Figure 10.1).
A simple technique for easier anterior odontoid screw fixation
Published in British Journal of Neurosurgery, 2019
Mohamed F. Khattab, Ahmed Nageeb Mahmoud, Ahmed Saeed Younis, Youssry El-Hawary
All patients with displaced odontoid fractures underwent reduction of the malalignment using Gardner-Wells tong skull traction (Figure 3), and serial cervical lateral radiographs were taken to confirm it. After endotracheal intubation, the patient was positioned supine with a roll behind the shoulders to allow neck extension. A high resolution image intensifiers was used. A radiolucent bite block was placed in the patient’s mouth to facilitate the open-mouth view. The lateral masses of C1, the vertebral body of C2, and the odontoid process could be visualized under anterior/posterior and lateral fluoroscopy. Before attempting anterior odontoid screw fixation, the patient’s head was secured using Gardner-Wells tongs with 2 kg of traction applied. Reduction status of the fracture was assessed under fluoroscopic visualization. Where necessary, gentle flexion and extension maneuvers were applied to achieve adequate reduction. The head was then kept in position with halter keeping the neck extended and fixed with plastering tape which prevented head movement. The presence of a direct trajectory was verified under fluoroscopy before surgery started. If satisfactory positioning is not achieved, we recommend abandoning anterior screw fixation but this did not happen in the present series.
Percutaneous retrogasserian glycerol rhizotomy for trigeminal neuralgia: an alternative technique
Published in British Journal of Neurosurgery, 2018
Menaka Pasangy Paranathala, Leon Ferguson, Richard Bowers, Nitin Mukerji
Traditionally this operation is performed following the Härtel anterior percutaneous technique, requiring intraoperative biplanar 2-dimensional projectional radiographs, or intraoperative computer tomography (CT)2–4 for the surgeon to plan the trajectory for the needle. Both these methods require the presence of a radiographer with prior experience of these procedures for manipulation of the Image Intensifier (II) for optimal radiographs. Though guided by the neurosurgeon, the technical part of taking the images requires trained staff for optimal images. This ensures the surgeon’s attention isn’t removed from the procedure, reduces the amount of time taken and the number of radiographs needed. With current NHS staffing levels and continuous rotation of radiographers this is increasingly difficult, therefore we modified our technique using Stealth frameless neuronavigation.
Retrospective analysis of coronary interventions in a single centre and comparison of specific differences between radial and femoral access
Published in Acta Cardiologica, 2019
Jakub Rychlik, Ivan Hornacek, Miloslav Tejc, Erik Petrikovits, Zdenek Klimsa
All three operators work in continuous service. The operators perform at least 700 coronary angiographies per year, and they performed at least 4000 coronary angiographies before 2012. All procedures were performed using a Philips Integris Allura 10F image intensifier system. The system was set to pulsed fluoroscopy at 10 pulses per second and cine acquisition at 15 frames per second. Diameter of image intensifier of 20 cm was used for all patients with appropriate collimation. We included only those patients who were intervened via superficial or common femoral artery and left or right radial artery. Preferential access in most cases was right radial. Patients with CABG from left internal mammary artery to left anterior descending artery underwent procedure via left radial access or as a second option via femoral artery access. Compression for radial access was performed with TR band® immediately after sheath removal. Compression in patients after intervention via femoral access was based on the type of procedure. Those who underwent diagnostic coronarography were manually compressed for required time in minutes immediately after the procedure (size of the sheath in French multiplied by 3), and after that, the access site was compressed with SJM Femostop™ for 4 hours. Patients who received at least one stent during the procedure were left with a sheath in the access vessel for 3 hours. After that, the access site was manually compressed for the required time in minutes (size of the sheath in French multiplied by 3) and patients received Cathofix compression system with two sandbags for 12 hours or SJM Femostop™ for 4 hours as a second option.