Pulsation and Collimation During Fluoroscopy to Decrease Radiation: A Cadaver Study

Optimizing neurointerventional procedures: an algorithm for embolization coil detection and automated collimation to enable dose reduction

Purpose

Monitoring radiation dose and time parameters during radiological interventions is crucial, especially in neurointerventional procedures, such as aneurysm treatment with embolization coils. The algorithm presented detects the presence of these embolization coils in medical images. It establishes a bounding box as a reference for automated collimation, with the primary objective being to enhance the efficiency and safety of neurointerventional procedures by actively optimizing image quality while minimizing patient dose.

Methods

Two distinct methodologies are evaluated in our study. The first involves deep learning, employing the Faster R-CNN model with a ResNet-50 FPN as a backbone and a RetinaNet model. The second method utilizes a classical blob detection approach, serving as a benchmark for comparison.

Results

We performed a fivefold cross-validation, and our top-performing model achieved mean mAP@75 of 0.84 across all folds on validation data and mean mAP@75 of 0.94 on independent test data. Since we use an upscaled bounding box, achieving 100% overlap between ground truth and prediction is not necessary. To highlight the real-world applications of our algorithm, we conducted a simulation featuring a coil constructed from an alloy wire, effectively showcasing the implementation of automatic collimation. This resulted in a notable reduction in the dose area product, signifying the reduction of stochastic risks for both patients and medical staff by minimizing scatter radiation. Additionally, our algorithm assists in avoiding extreme brightness or darkness in X-ray angiography images during narrow collimation, ultimately streamlining the collimation process for physicians.

Conclusion

To our knowledge, this marks the initial attempt at an approach successfully detecting embolization coils, showcasing the extended applications of integrating detection results into the X-ray angiography system. The method we present has the potential for broader application, allowing its extension to detect other medical objects utilized in interventional procedures.

Evolution of Cervical Endoscopic Spine Surgery: Current Progress and Future Directions-A Narrative Review

Cervical endoscopic spine surgery is rapidly evolving and gaining popularity for the treatment of cervical radiculopathy and myelopathy. This approach significantly reduces muscular damage and blood loss by minimizing soft tissue stripping, leading to less postoperative pain and a faster postoperative recovery. As scientific evidence accumulates, the efficacy and safety of cervical endoscopic spine surgery are continually affirmed. Both anterior and posterior endoscopic approaches have surfaced as viable alternative treatments for various cervical spine pathologies. Newer techniques, such as endoscopic-assisted fusion, the anterior transcorporeal approach, and unilateral laminotomy for bilateral decompression, have been developed to enhance clinical outcomes and broaden surgical indications. Despite its advantages, this approach faces challenges, including a steep learning curve, increased radiation exposure for both surgeons and patients, and a relative limitation in addressing multi-level pathologies. However, the future of cervical endoscopic spine surgery is promising, with potential enhancements in clinical outcomes and safety on the horizon. This progress is fueled by integrating advanced imaging and navigation technologies, applying regional anesthesia for improved and facilitated postoperative recovery, and incorporating cutting-edge technologies, such as augmented reality. With these advancements, cervical endoscopic spine surgery is poised to broaden its scope in treating cervical spine pathologies while maintaining the benefits of minimized tissue damage and rapid recovery.

Image Quality and Radiation Exposure in Abdominal Angiography: A Head-to-Head Comparison of Conventional Detector-Dose-Driven Versus Contrast-to-Noise Ratio-Driven Exposure Control at Various Source-to-Image Receptor Distances and Collimations in a Pilot Phantom and Animal Study

OBJECTIVES

This phantom and animal pilot study aimed to compare image quality and radiation exposure between detector-dose-driven exposure control (DEC) and contrast-to-noise ratio (CNR)-driven exposure control (CEC) as functions of source-to-image receptor distance (SID) and collimation.

MATERIALS AND METHODS

First, an iron foil simulated a guide wire in a stack of polymethyl methacrylate and aluminum plates representing patient thicknesses of 15, 25, and 35 cm. Fluoroscopic images were acquired using 5 SIDs ranging from 100 to 130 cm and 2 collimations (full field of view, collimated field of view: 6 × 6 cm). The iron foil CNRs were calculated, and radiation doses in terms of air kerma rate were obtained and assessed using a multivariate regression. Second, 5 angiographic scenarios were created in 2 anesthetized pigs. Fluoroscopic images were acquired at 2 SIDs (110 and 130 cm) and both collimations. Two blinded experienced readers compared image quality to the reference image using full field of view at an SID of 110 cm. Air kerma rate was obtained and compared using t tests.

RESULTS

Using DEC, both CNR and air kerma rate increased significantly at longer SID and collimation below the air kerma rate limit. When using CEC, CNR was significantly less dependent of SID, collimation, and patient thickness. Air kerma rate decreased at longer SID and tighter collimation. After reaching the air kerma rate limit, CEC behaved similarly to DEC. In the animal study using DEC, image quality and air kerma rate increased with longer SID and collimation (P < 0.005). Using CEC, image quality was not significantly different than using longer SID or tighter collimation. Air kerma rate was not significantly different at longer SID but lower using collimation (P = 0.012).

CONCLUSIONS

CEC maintains the image quality with varying SID and collimation stricter than DEC, does not increase the air kerma rate at longer SID and reduces it with tighter collimation. After reaching the air kerma rate limit, CEC and DEC perform similarly.

Radiation exposure doses to the surgical team during hip surgery is significantly higher during lateral imaging than posteroanterior imaging: a cadaveric simulation study

BACKGROUND

Fluoroscopy is indispensable when determining appropriate and effective interventions in orthopedic surgery. On the other hand, there is growing concern about the health hazards of occupational radiation exposure. The aim of this cadaveric simulation study was to measure radiation exposure doses to the surgical team during hip surgery.

METHODS

We reproduced the intraoperative setting of hip surgery using 7 fresh frozen cadavers (5 male, 2 female) to simulate patients and mannequins to simulate the surgeon, scrub nurse, and anesthesiologist. Six real-time dosimeters were mounted at sites corresponding to the optic lens, thyroid gland, chest, gonads, foot, and hand on each mannequin. The radiation exposure dose to each team member was measured during posteroanterior and lateral fluoroscopic imaging.

RESULTS

Radiation exposure doses to the surgeon were significantly higher during 3 min of lateral imaging than during 3 min of posteroanterior imaging at the optic lens (8.1 times higher), thyroid gland (10.3 times), chest (10.8 times), and hand (19.8 times) (p = 0.018, p = 0.018, p = 0.018, and p = 0.018, respectively). During lateral imaging, the radiation doses to the nurse were 0.16, 0.12, 0.09, 0.72, and 0.38 times those to the surgeon at the optic lens, thyroid, chest, gonads, and foot, respectively. The radiation dose to the anesthesiologist was zero at all anatomic sites during posteroanterior imaging and very small during lateral imaging.

CONCLUSIONS

Radiation exposure dose was significantly higher during lateral imaging up to 19.8 times comparing to the posteroanterior imaging. It is effective to reduce the lateral imaging time for reducing the intraoperative radiation exposure. In addition, appropriate distance from fluoroscopy resulted in very low exposure for nurses and anesthesiologists. Surgeon should pay attention that surgical staff do not get closer than necessary to the irradiation field.

A Cadaveric Simulation Study of Radiation Exposure to the Surgical Team during Fluoroscopic Spinal Surgery: How Much Are We Exposed?

Introduction

The harmful effects of long-term low-dose radiation have been well known. There are few comprehensive reports evaluating concrete real exposure doses for each part of a surgeon, assistant surgeon, scrub nurse, and anesthesiologist associated with fluoroscopic spinal procedures. This research aimed to quantify the radiation exposure dose to surgical team members during C-arm fluoroscopy-guided spinal surgery.

Methods

Seven fresh cadavers were irradiated for 1 and 3 min with C-arm fluoroscopy. The position of the X-ray source was under the table, over the table, and laterally. The radiation exposure doses were measured at the optic lens, thyroid gland, and hand in mannequins used to simulate surgical team members.

Results

A significant difference was observed in the radiation exposure dose according to the position of the X-ray source and the irradiated body area. The risk of scatter radiation exposure was the biggest for the lateral position (nearly 30-fold that for the position under the table). All radiation exposure doses were positively correlated with irradiation time.

Conclusions

The occupational radiation exposure dose to surgical team members during C-arm fluoroscopy-guided lumbar spinal procedures varies according to the X-ray source position. Our findings would help surgical team members to know the risk of radiation exposure during various fluoroscopic procedures. Surgeons in particular need to reduce their radiation exposure by using appropriate shielding and technique.

Current and potential applications of artificial intelligence in medical imaging practice: A narrative review

BACKGROUND AND PURPOSE

Artificial intelligence (AI) is present in many areas of our lives. Much of the digital data generated in health care can be used for building automated systems to bring improvements to existing workflows and create a more personalised healthcare experience for patients. This review outlines select current and potential AI applications in medical imaging practice and provides a view of how diagnostic imaging suites will operate in the future. Challenges associated with potential applications will be discussed and healthcare staff considerations necessary to benefit from AI-enabled solutions will be outlined.

METHODS

Several electronic databases, including PubMed, ScienceDirect, Google Scholar, and University College Dublin Library Database, were used to identify relevant articles with a Boolean search strategy. Textbooks, government sources and vendor websites were also considered.

RESULTS/DISCUSSION

Many AI-enabled solutions in radiographic practice are available with more automation on the horizon. Traditional workflow will become faster, more effective, and more user friendly. AI can handle administrative or technical types of work, meaning it is applicable across all aspects of medical imaging practice.

CONCLUSION

AI offers significant potential to automate most of the manual tasks, ensure service consistency, and improve patient care. Radiographers, radiation therapists, and clinicians should ensure they have adequate understanding of the technology to enable ethical oversight of its implementation.

[Intraoperative imaging of children and adolescents, for selected fractures and in follow-up after conservative and operative treatment : Part 2 of the results of a nationwide online survey of the Pediatric Traumatology Section of the German Trauma Society]

The indication for radiographic examinations in pediatric and adolescent trauma patients should follow ALARA (as low as reasonably achievable). Because of the effect of radiation on the growing sensitive tissues of these young patients, a strict indication should always be given for radiation use and during controls after fracture repair.

METHODS

An online survey by the Pediatric Traumatology Section (SKT) of the German Trauma Society (DGU) from Nov. 15, 2019, to Feb. 29, 2020, targeting trauma, pediatric, and general surgeons and orthopedic surgeons.

RESULTS

Participants: 788. Intraoperative applications: Collimation 50% always, postprocessing for magnification 40%, pulsed x-ray 47%, and 89% no continuous fluoroscopy; 63% osteosynthesis never directly on image intensifier. Radiographic controls after implant removal never used by 24%. After operated supracondylar humerus fracture, controls are performed up to 6 times. After distal radius greenstick fracture, 40% refrain from further X-ray controls, after conservatively treated clavicular shaft fracture, 55% refrain from further controls, others X-ray several times. After nondisplaced conservatively treated tibial shaft fracture, 63% recommend radiographic control after 1 week in two planes, 24% after 2 weeks, 37% after 4 weeks, and 32% after 6 weeks.

DISCUSSION

The analysis shows that there is no uniform radiological management of children and adolescents with fractures among the respondents. For some indications for the use of radiography, the benefit does not seem evident. The ALARA principle does not seem to be consistently followed.

CONCLUSION

Comparing the documented results of the survey with the consensus results of the SKT, differences are apparent.

Radiation Exposure Among Orthopaedic Trauma Surgeons: Deconstructing Commonly Held Myths and Misperceptions

OBJECTIVES

To review and evaluate the validity of common perceptions and practices regarding radiation safety in orthopaedic trauma.

DESIGN

Retrospective study.

SETTING

Level 1 trauma center.

SUBJECTS

N/A.

INTERVENTION

The intervention involved personal protective equipment.

MAIN OUTCOME MEASUREMENTS

The main outcome measurements included radiation dose estimates.

RESULTS

Surgeon radiation exposure estimates performed at the level of the thyroid, chest, and pelvis demonstrate an estimated total annual exposure of 1521 mR, 2452 mR, and 1129 mR, respectively. In all cases, wearing lead provides a significant reduction (90% or better) in the amount of radiation exposure (in both radiation risk and levels of radiation reaching the body) received by the surgeon. Surgeons are inadequately protected from radiation exposure with noncircumferential lead. The commonly accepted notion that there is negligible exposure when standing greater than 6 feet from the radiation source is misleading, particularly when cumulative exposure is considered. Finally, we demonstrated that trauma surgeons specializing in pelvis and acetabular fracture care are at an increased risk of exposure to potentially dangerous levels of radiation, given the amount of radiation required for their caseload.

CONCLUSION

Common myths and misperceptions regarding radiation in orthopaedic trauma are unfounded. Proper use of circumferential personal protective equipment is critical in preventing excess radiation exposure.

Efficiency of novel shielding curtains combined with pulsed irradiation for reducing radiation exposure in an operating room: Human renal collecting system phantom study

OBJECTIVE

To evaluate the impact of novel shielding curtains combined with pulsed irradiation mode to protect medical radiation workers from radiation exposure during ureteroscopy.

METHODS

0.25 mm Pb equivalent novel shielding curtains were mounted to the caudal and bilateral sides of the operating table in the ureteroscopy setting. C-arm was positioned as per normal in the operating room with the X-ray tube under the patient table. A water-filled anthropomorphic renal collecting system phantom was positioned in the standard position on the operating table that was set at a height of 100 cm. The ionization chambers were also positioned at a height of 100 cm and set in eight positions. We took measurements at distances of 50, 100, 150, and 200 cm from the phantom with the focus directed toward the X-ray tube. We measured the spatial distribution of the scattered radiation dose in four combinations: (1) continuous irradiation mode without novel shielding curtains; (2) pulsed irradiation mode (11 films per second) without novel shielding curtains; (3) continuous irradiation mode with novel shielding curtains; and (4) pulsed irradiation mode with novel shielding curtains. Continuous or pulsed irradiation was activated for 30 s each time.

RESULTS

Pulsed irradiation mode with novel shielding curtains was a significantly more efficient method than other combinations to reduce scattered radiation exposure in this study (P < 0.001). There was approximately a 95% reduction in scattered radiation exposure with the pulsed irradiation mode with novel shielding curtains set up as compared with continuous irradiation mode without novel shielding curtains.

CONCLUSION

Combining a novel shielding curtain and using a low pulse radiation setting can greatly reduce radiation exposure during ureteroscopic procedures.

Collimation Reduces Radiation Exposure to the Surgeon in Endoscopic Spine Surgery: A Prospective Study

BACKGROUND AND STUDY AIMS

 There are no previous studies in the literature comparing the radiation dose to which surgeons are exposed while using a standard fluoroscopy versus collimation during transforaminal percutaneous endoscopic lumbar diskectomy (PELD). The aim of this study is to compare this and to evaluate the effectiveness of collimation in reducing radiation exposure.

METHODS

 In this study, the operating surgeon (single surgeon) placed a gamma radiation dosimeter on his chest outside of the lead apron during transforaminal PELD surgeries and measured the radiation exposure immediately after each surgery. As foraminoplasty using free-hand reamers is a longer procedure and requires more fluoroscopy shots, we divided the patients into two groups. The first group consisted of 24 patients (nonforaminoplasty group). The second group consisted of 13 patients (foraminoplasty group). We compared the radiation exposure to the operating surgeon using a standard fluoroscopy versus collimation for each group individually and overall. We randomized the patients within each group based on the order in which they had their respective procedures.

RESULTS

 We analyzed 39 patients who underwent transforaminal PELD between May and December 2019. In both groups, as well as overall, the recorded radiation exposure to the surgeon was significantly lower in surgeries in which collimation was used. In the first group, the radiation dose was 0.083 versus 0.039 mSv per surgery (p = 0.019), whereas in the second group, it was 0.153 versus 0.041 mSv per surgery (p = 0.001), and overall it was 0.108 versus 0.039 mSv per surgery (p < 0.001).

CONCLUSION

 The use of collimation during transforaminal PELD significantly reduces spine the surgeon's exposure to radiation. Therefore, spine surgeons should consider using collimation during transforaminal PELD.

The use of ionising radiation in orthopaedic surgery: principles, regulations and managing risk to surgeons and patients

The use of ionising radiation for plain film radiography and computerised tomography is fundamental in both diagnostics and treatment for orthopaedics. However, radiation is not without risk as high exposure can increase the risk of cancer. Little time is spent educating doctors about the relative risks of radiation, both to patients and themselves. In addition, there are common misunderstandings about the best ways to mitigate such risk. We aim to provide an overview of the fundamental principles of the use of ionising radiation and its risks within the context of orthopaedic surgery. While providing a narrative review of the current literature, we discuss the basic physics, standards of good practice and relevant UK and European regulations. We discuss the risks to patients and surgeons and suggest ways that these can be mitigated in the operating theatre. A thorough understanding of the risks, and appropriate procedural rules, with respect to the use of ionising radiation is essential for those in orthopaedic practice.

Intraoperative risks of radiation exposure for the surgeon and patient

Intraoperative radiological imaging serves an essential role in many spine surgery procedures. It is critical that patients, staff and physicians have an adequate understanding of the risks and benefits associated with radiation exposure for all involved. In this review, we briefly introduce the current trends associated with intraoperative radiological imaging. With the increased utilization of minimally invasive spine surgery (MIS) techniques, the benefits of intraoperative imaging have become even more important. Less surgical exposure, however, often equates to an increased requirement for intraoperative imaging. Understanding the conventions for radiation measurement, radiological fundamental concepts, along with deterministic or stochastic effects gives a framework for conceptualizing how radiation exposure relates to the risk of various sequela. Additionally, we describe the various options surgeons have for intraoperative imaging modalities including those based on conventional fluoroscopy, computer tomography, and magnetic resonance imaging. We also describe different ways to prevent unnecessary radiation exposure including dose reduction, better education, and use of personal protective equipment (PPE). Finally, we conclude with a reflection on the progress that has been made to limit intraoperative radiation exposure and the promise of future technology and policy.