Objective.Digitally reconstructed radiography (DRR) plays an important role in the registration of intraoperative x-ray and preoperative CT images. However, existing DRR algorithms often neglect the critical isocentric fixed angle irradiation (IFAI) principle in C-arm imaging, resulting in inaccurate simulation of x-ray images. This limitation degrades registration algorithms relying on DRR image libraries or employing DRR images (DRRs) to train neural network models. To address this issue, we propose a novel IFAI-based DRR method that accurately captures the true projection transformation during x-ray imaging of the human body.Approach.By strictly adhering to the IFAI principle and utilizing known parameters from intraoperative x-ray images paired with CT scans, our method successfully simulates the real projection transformation and generates DRRs that closely resemble actual x-ray images.Main result.Experimental results validate the effectiveness of our IFAI-based DRR method by successfully registering intraoperative x-ray images with preoperative CT images from multiple patients who underwent thoracic endovascular aortic procedures.Significance. The proposed IFAI-based DRR method enhances the quality of DRR images, significantly accelerates the construction of DRR image libraries, and thereby improves the performance of x-ray and CT image registration. Additionally, the method has the generality of registering CT and x-ray images generated by large C-arm devices.

UNASSIGNED: To demonstrate the utility of routine intraoperative plain film imaging in optimizing outcomes in cochlear implantation.
UNASSIGNED: Evolving surgical techniques, programming, and electrode arrays have all improved performance outcomes in cochlear implantation. Yet despite decreasing complication rates, electrode misplacement remains a common occurrence. Utilization of intraoperative confirmational tools (radiologic, electrophysiologic) remains unstandardized despite the acknowledged importance of proper electrode positioning. The purpose of this article is to illustrate the use and benefits of intraoperative X-ray (IOXR) in four cases, particularly in cases of normal electrophysiologic testing.
UNASSIGNED: Four cases performed by an experienced CI surgeon are discussed where electrode malposition was only detected through X-ray. Literature review was performed on the use of intraoperative imaging, focusing on plain film radiography.
UNASSIGNED: Case 1-3 describe examples of resistance-free electrode insertion in patients with normal pre-operative imaging. Intraoperative impedances and neural response telemetry (NRT) were normal. However, IOXR ultimately revealed tip fold-over prompting array repositioning. Case 4 describes an elective replacement of a soft-failing device. Resistance was encountered during array insertion, with IOXR demonstrating incomplete insertion compared with prior imaging. Positioning was revised to achieve pre-revision insertion depth, demonstrating the utility of prior IOXR in revision cases. Literature review of IOXR is discussed.
UNASSIGNED: Appropriate placement of the electrode is paramount to successful CI outcomes. These cases illustrate IOXR as a safe, effective method to ensure optimal placement even in cases of normal electrophysiologic testing, supporting its routine use even by the most seasoned surgeons.

Cranial gunshot wounds (CGSWs) are the most lethal types of the cranial traumas and they are usually mortal. Falling bullets or gravitational bullets are the ones that move under the effect of the gravity force after the muzzle force diminished. CGSWs constitute a major clinical challenge for neurosurgeons dealing with trauma in both the military and civil experience. We report the case of a 21-year-old man with a falling bullet wound to the head. The decision of surgical treatment of a bullet injury is difficult if it is in close proximity to vital structures; removal of the bullet may cause significant neurological damage; however, migration can lead to a worsening of the neurological status of the patient. Before surgical removal of any intracranial bullet, as valuable information, it is recommended that a plain skull X-ray be obtained after final positioning of the head.

To evaluate the feasibility, efficacy, and morbidity of Essure® device removal via laparoscopic en bloc salpingectomy-cornuectomy resection (LSC) and the utility of confirmation of complete removal with an intraoperative X-ray of the removed specimen (IX-S).
Retrospective observational cohort study.
Academic hospitals of La Conception, Marseille, and Arnaud-de-Villeneuve, Montpellier, France.
Women who were not seeking future fertility seeking Essure® device removal by salpingectomy, between February 2017 and August 2018.
All women underwent LSC. An IX-S was performed to confirm complete Essure® device removal. In the case of an unsatisfactory IX-S, an intraoperative pelvic X-ray control of the patient (IX-P) was performed. If IX-P diagnosed residual Essure® fragments, an additional resection was performed, and the removed tissue was checked by IX-S.
We included 72 women, and a total of 140 Essure® devices were removed. The IX-S confirmed complete Essure® device removal in 131 of 140 cases (93.6%) in 63 of 72 women (87.5%). Out of the 9 women with unsatisfactory IX-S, 6 had no residual Essure® fragments at IX-P, and Essure® device removal was considered complete. Three women had a persistent Essure® fragment at IX-P: an additional resection allowed complete removal in 2 cases and resulted in failure in 1 of 140 case (0.7%). There were 2 of 72 women (2.8%) intraoperative complications and 4 of 72 women (5.6%) postoperative grade 1 complications according to the Clavien-Dindo classification.
Essure® device removal by LSC appears to be an effective and safe procedure. IX-S is a useful method to evaluate whether the removal of Essure® device is complete during an LSC procedure.