The effectiveness of the Safety in Interventional Radiology (SIR) Shield in reducing droplet transmission and its effect on image quality and radiation dose.

OBJECTIVE: To evaluate the efficacy of a barrier shield in reducing droplet transmission and its effect on image quality and radiation dose in an interventional suite. METHODS: A human cough droplet visualisation model in a supine position was developed to assess efficacy of barrier shield in reducing environmental contamination. Its effect on image quality (resolution and contrast) was evaluated via image quality test phantom. Changes in the radiation dose to patient post-shield utilisation was measured. RESULTS: Use of the shield prevented escape of visible fluorescent cough droplets from the containment area. No subjective change in line-pair resolution was observed. No significant difference in contrast-to-noise ratio was measured. Radiation dosage to patient was increased; this is predominantly attributed to the increased air gap and not the physical properties of the shield. CONCLUSION: Use of the barrier shield provided an effective added layer of personal protection in the interventional radiology theatre for aerosol generating procedures. ADVANCES IN KNOWLEDGE: This is the first time a human supine cough droplet visualisation has been developed. While multiple types of barrier shields have been described, this is the first systematic practical evaluation of a barrier shield designed for use in the interventional radiology theatre.

New infusion device for use in acquisition of images during endovascular procedures: an experimental model / Novo dispositivo de infusão para a aquisição de imagens durante procedimentos endovasculares: modelo experimental

Abstract Background The contrast power injector (CPI) is the gold standard method for injecting contrast with the pressure and flow needed to generate a satisfactory images during endovascular procedures, but it is an expensive tool, narrowing its wide-scale applications. One alternative is the manual injection (MI) method, but this does not generate the pressure required for adequate visualization of anatomy. It is therefore imperative to create an alternative low-cost method that is capable of producing high quality images. Objectives To compare the injection parameters of a new mechanical device (Hand-Crank) created in a university hospital with the MI method and with the contrast power injector's ideal values. Methods A circulation phantom was constructed to simulate the pressure in the aorto-iliac territory and the injection parameters of the two methods were compared in a laboratory setting. Student's t test and the Mann-Whitney test were used for statistical analysis. Three vascular surgery residents (the authors) performed the injections (each performed 9 tests using conventional manual injection and 9 tests using the Hand-Crank, totaling 54 injections). Results There were statistical differences between the two methods (p<0.05) in total volume injected until maximum pressure was attained, pressure variation, maximum pressure, total injection time, and time to reach the maximum pressure. Conclusions The Hand-Crank can achieve higher maximum pressure, higher average flow, and lower injection time than the manual method. It is a simple, low-cost, and effective tool for enhancing injection parameters in an experimental setup. It could help to produce higher quality images in a clinical scenario.

Resumo Contexto A bomba injetora é o método padrão-ouro para a injeção de contraste em aortografias. Entretanto, é uma ferramenta de alto custo, o que limita o seu uso. A injeção manual surge como alternativa, mas a pressão gerada com esse método é baixa, e, por isso, a qualidade das imagens não é usualmente satisfatória. Assim, a criação de um método de baixo custo capaz de gerar imagens de qualidade é imperativo. Objetivos Comparar os parâmetros de injeção de um novo dispositivo mecânico (manivela articulada) criado em um hospital universitário com os parâmetros da injeção manual e com os valores ideais da bomba injetora. Métodos Um simulador do território aórtico foi construído, e parâmetros de injeção entre os diferentes métodos em um cenário laboratorial controlado foram analisados. O teste t de Student e o teste de Mann-Whitney foram usados para análise estatística. Três residentes de Cirurgia Vascular realizaram os testes (nove usando o novo dispositivo, e nove usando a injeção manual, totalizando 54 injeções). Resultados Houve diferença estatisticamente significativa (p < 0,05) entre os dois métodos, considerando os parâmetros: variação de pressão, pressão máxima, tempo de injeção, tempo até a pressão máxima e volume até a pressão máxima. Conclusões A manivela articulada atingiu níveis superiores de pressão e de velocidade de injeção, com menor tempo de injeção do que a injeção manual. É um dispositivo simples, de baixo custo e com resultados comparáveis à bomba injetora, o que sugere seu uso potencial na geração de imagens satisfatórias em aortografias.

Interventional radiology under the era of coronavirus disease 2019: Recommendations from the Chinese College of Interventionalists.

The pandemic of coronavirus disease 2019 (COVID-19) has become a major public health threat to the whole world. Although the control of COVID-19 has been in the forefront of interventional practice, most interventional radiologists (IRs) are not equipped adequately to cope with such a crisis. In this review, we share our experience from Chinese IRs' perspective, report on the acute measures instituted within interventional radiology (IR) units, and give recommendations to the prevention and control of COVID-19.

An initial investigation of a wireless patient radiation dosimeter for use in interventional radiology.

Radiation exposure during interventional radiology (IR) procedures is a critical issue. We have developed a wireless real-time dosimeter for IR patients that use nontoxic phosphor (four sensors). We evaluated the basic performance parameters (such as dose linearity, batch uniformity, reproducibility, and wireless-communication conditions) of the developed system using an IR X-ray system. Further, we investigated the influence of noise from other medical equipment on our wireless real-time dosimeter in the IR X-ray room. Overall, our wireless system exhibited excellent performance in terms of uniformity, reproducibility, and linearity; moreover, the wireless communication performance was better. The developed system enabled real-time visualization of patient radiation dose, without noise contamination from other medical equipment. In addition, the wireless system can be easily installed in a location where the PC screen (display) can be readily viewed by the IR physician. Hence, we developed a wireless system that can display the patient radiation dose data in real time; the system performed satisfactorily upon application in radiation dosimetry. Therefore, our wireless system will facilitate the real-time monitoring/management of patient radiation dose during IR.

Transradial intracranial aneurysm treatment via an aberrant right subclavian artery.

We report two cases of successfully treated intracranial saccular aneurysms via transradial access with aberrant right subclavian artery anatomy. Two patients aged 74 and 82 years with anterior communicating artery aneurysms deemed suitable for endovascular treatment and anomalous aortic arch anatomy (aberrant right subclavian artery) underwent successful treatment with transradial access. Transradial access was obtained in both patients, in the first patient, without prior knowledge of the aortic arch anatomy. Aberrant right subclavian artery anatomy was negotiated, and the aneurysms were successfully treated in both cases with intrasaccular flow disrupting devices (WEB-SL).

Titration of extra-PEEP against intrinsic-PEEP in severe asthma by electrical impedance tomography: A case report and literature review.

RATIONALE: The use of extra-positive end-expiratory pressure (PEEP) at a level of 80% intrinsic-PEEP (iPEEP) to improve ventilation in severe asthma patients with control ventilation remains controversial. Electrical impedance tomography (EIT) may provide regional information for determining the optimal extra-PEEP to overcome gas trapping and distribution. Moreover, the experience of using EIT to determine extra-PEEP in severe asthma patients with controlled ventilation is limited. PATIENTS CONCERNS: A severe asthma patient had 12-cmH2O iPEEP using the end-expiratory airway occlusion method at Zero positive end-expiratory pressures (ZEEP). How to titrate the extra-PEEP to against iPEEP at bedside? DIAGNOSES AND INTERVENTIONS: An incremental PEEP titration was performed in the severe asthma patient with mechanical ventilation. An occult pendelluft phenomenon of the ventral and dorsal regions was found during the early and late expiration periods when the extra-PEEP was set to <6 cmH2O. If the extra-PEEP was elevated from 4 to 6 cmH2O, a decrease in the end-expiratory lung impedance (EELI) and a disappearance of the pendelluft phenomenon were observed during the PEEP titration. Moreover, there was broad disagreement as to the "best" extra-PEEP settings according to the various EIT parameters. The regional ventilation delay had the lowest extra-PEEP value (10 cmH2O), whereas the value was 12 cmH2O for the lung collapse/overdistension index and 14 cmH2O for global inhomogeneity. OUTCOMES: The extra-PEEP was set at 6 cmH2O, and the severe whistling sound was improved. The patient's condition further became better under the integrated therapy. LESSONS: A broad literature review shows that this was the 3rd case of using EIT to titrate an extra-PEEP to against PEEPi. Importantly, the visualization of occult pendelluft and possible air release during incremental PEEP titration was documented for the first time during incremental PEEP titration in patients with severe asthma. Examining the presence of the occult pendelluft phenomenon and changes in the EELI by EIT might be an alternative means for determining an individual's extra-PEEP.

COVID-19 Outbreak: Infection Control and Management Protocol for Vascular and Interventional Radiology Departments-Consensus Document.

COVID-19 (SARS-CoV-2 virus) pandemic was recently declared by the WHO as a global health emergency. A group of interventional radiology senior experts developed a consensus document for infection control and management of patients with COVID-19 in interventional radiology (IR) departments. This consensus statement has been brought together at short notice with the help of different protocols developed by governmental entities and scientific societies to be adapted to the current reality and needs of IR Departments. Recommendations are the specific strategies to follow in IR departments, preventive measures and regulations, step by step for donning and doffing personal protective equipment, specific IR procedures which can not be delayed, and aerosol-generating procedures in IR with COVID-19 patients. It is advisable with this document to be adapted to local workplace policies.

Evaluation of scattered radiation dose received by medical staff during uterine artery embolization in the operating room.

BACKGROUND: The air kerma radiation doses have gained much attention since the operating room interventional radiology is a place where medical staff are exposed to a fluoroscopy environment and gain a cumulative dose during the uterine artery embolization procedure. OBJECTIVE: We aimed to evaluate the radiation dose received by medical staff by applying a flat X-ray machine in the surgical room during uterine artery embolization. METHODS: An ATOM humanoid model was laid on the operating table and simulated a patient. The scattered radiation dose received by the radiologist, anesthetist and radiologic technologist was evaluated. The scintillation detector was adopted. The measurement points were 50 cm, 100 cm and 150 cm above the floor, representing the limbs, abdomen and thyroid level, respectively. We compared the X-rays under different tube voltages of 70, 80, and 90, respectively and frames per second (FPS) of 30, 15, and 7.5, respectively. We configured the dose level per pulse of 40 nGy with a fixed detector. RESULTS: In Section 1, when the tube voltage was 70 kVp and 7.5 FPS, the average radiation doses of limbs, abdomen and thyroid level was 0.48, 1.3 and 1.9 µSv/min respectively. When the tube voltage was 80 kVp and the fluoroscopy decreases from 30 FPS to 7.5 FPS, 58% of the radiation dose was reduced. When the tube voltage was 90 kVp, the radiation dose in the lead garment increased 31-177% in comparison to when the tube voltage was 80 kVp. Sections 2 and 3 were far away from the central ray, so the highest radiation dose 100 cm above the floor were 0.05 and 0.02 µSv/min. CONCLUSIONS: Lead garment can effectively reduce medical staff from occupational doses with an average attenuation rate of 90%. 80 kVp was most commonly used. Fluoroscopy 7.5 FPS was used 100 cm above the floor in A section and the lowest radiation dose was 1.33 µSv/min. The operator should decrease the duration of X-rays or adopt suspended lead shielding to decrease the radiation dose received by the operator. When kVp increases, the penetration increases. Decreasing FPS cannot decrease occupational doses of medical staff.

Assessing the Burden of Packaging and Recyclability of Single-Use Products in Interventional Radiology.

PURPOSE: With a shift to single-use products in interventional radiology (IR) centres for sterility and cost reasons, it is prudent to consider the burden of packaging and employ efforts to assess and reduce waste, as well as promote recycling wherever possible. This study aimed to quantify the amount of waste in IR packaging and what proportion is recyclable. MATERIALS AND METHODS: A range of IR products were weighed using mass scales. Products were assessed for total weight, overall waste, and potentially recyclable waste. Waste was defined as any packaging which was not considered vital to the product to perform its duty and thus was for packaging or shipping purposes. Products were pooled into one of the following categories: catheters and sheaths, wires, needles, devices, coils, and packs/ancillary. RESULTS: Seventy-two different products were collected from 26 manufacturers to represent a range of items. The weight of all products was 12,466 g (median 51, range 2-1600), and weight of waste was 6830.7 g (median 34, range 1.1-732). The weight of recyclable waste was 5202.2 g (median 11.5, range 0-701). There were median 2 waste packages per item (range 1-5). The proportion of waste of the overall weight was 54.8% and of this, 76% of all waste was potentially recyclable. CONCLUSION: There is a significant burden of waste in manufactured IR products, and while a high proportion is recyclable, we encourage manufacturers of IR products and devices to consider alternative means of transport and packaging of products which will reduce the overall waste burden. LEVEL OF EVIDENCE: Level 3.

[Interventional radiology as emergency therapy]. / Interventionelle Radiologie als Notfalltherapie.

CLINICAL ISSUE: Both the progress of surgical techniques and the demographic development with increasing numbers of multimorbid patients demand and also encourage radiology in the setting of trauma and acute emergencies. In addition to a fast and precise diagnostics, this also includes image-guided, minimally invasive therapy to control and treat several acute pathologies. STANDARD RADIOLOGICAL PROCEDURES: Computed tomography (CT) is not only important for the diagnosis of abscesses, active bleeding or other acute pathologies, but also allows minimally invasive therapy. While digital subtraction angiography (DSA) guides catheter-based procedures, e.g., to control bleedings or to place percutaneous transhepatic cholangiodrain (PTCD), fluoroscopy allows the 3D-visualization to drain abdominal and thoracic abscesses. METHODOLOGICAL INNOVATION AND EVALUATION: Radiology has established itself in the treatment of acute emergencies or acute complications through gentle and usually fast minimally invasive procedures. Presumably, MRI interventions will become increasingly important in the near future and, thus, complement the portfolio. PRACTICAL RECOMMENDATIONS: Every clinical radiologist who works on night shifts should be able to safely carry out some basic interventional techniques in order to stabilize the patient and at least ensure medically safe bridging to the next routine workday. Due to the diversity of materials and the rarity and difficulty of some procedures, the full portfolio requires years of expertise and will therefore remain restricted to specialized interventional radiologists.

Reduction of Occupational Exposure Using a Novel Tungsten-Containing Rubber Shield in Interventional Radiology.

This study investigates whether a novel tungsten-containing rubber shield could be used as substitute shielding material in interventional radiology to reduce the occupational exposure of operators to scattered radiation from a patient. The tungsten-containing rubber is a lead-free radiation-shielding material that contains as much as 90% tungsten powder by weight. Air kerma rates of scattered radiation from solid-plate phantoms, simulating a patient, were measured with a semiconductor dosimeter at the height of the operator's eye (1,600 mm from the floor), chest (1,300 mm), waist (1,000 mm), and knee (600 mm) with and without tungsten-containing rubber shielding (1-5 mm thickness). The tungsten-containing rubber and a commercial shielding material (RADPAD) were affixed onto the phantom on the operator's side, and reductions in air kerma rates were compared. Reduction rates for tungsten-containing rubber shielding with thicknesses of 1, 2, 3, 4, and 5 mm at each height level were as follows: 70.37 ± 0.40%, 72.17 ± 0.29%, 72.95 ± 0.31%, 72.58 ± 0.35%, and 73.63 ± 0.63% at eye level; 76.36 ± 0.19%, 77.13 ± 0.10%, 77.36 ± 0.14%, 77.62 ± 0.25%, and 77.66 ± 0.14% at chest level; 67.78 ± 0.31%, 68.12 ± 0.19%, 68.88 ± 0.28%, 68.97 ± 0.14%, and 68.85 ± 0.45% at waist level; and 0.14 ± 0.94%, 0.72 ± 0.56%, 1.08 ± 0.74%, 1.77 ± 0.80%, and 1.79 ± 1.82% at knee level, respectively. Reduction rates with RADPAD were 61.80 ± 0.67%, 60.33 ± 0.61%, 64.70 ± 0.25%, and 0.14 ± 0.66% at eye, chest, waist, and knee levels, respectively. The shielding ability of the 1 mm tungsten-containing rubber was superior to that of RADPAD. The tungsten-containing rubber could be employed to minimize an operator's radiation exposure instead of the commercial shielding material in interventional radiology.

Fan-Beam Based Virtual Fluoroscopy for Navigated Catheterization in Interventional Radiology.

Personalized medicine implies reducing invasiveness of therapeutic procedures. Although interventional radiology proved a very interesting alternative to surgical procedures, it still raises concerns due to the irradiation dose received by the medical team (and by the patient). We propose a novel concept allowing to reduce very significantly the irradiation dose during the phases where tools inserted in the patient have to be tracked with respect to previously acquired images. This implies inserting a miniaturized X-ray detector in the tip of the tools, and reducing the dose by a "rotating collimator". We demonstrate that real-time processing of the signals allows accurate localization of the tip of the tools, with a dose reduction of at least ten times.

Experimental Assessment of a Novel Touchless Interface for Intraprocedural Imaging Review.

PURPOSE: To examine the feasibility of a novel technology platform that enables real-time touchless interaction with radiology images in both a simulated and an actual clinical setting. MATERIALS AND METHODS: This platform offers three different modes for image interaction. The gesture recognition mode uses a depth camera to detect the user's hand gestures which are translated to image manipulation commands. The light projection mode uses the same camera to detect finger point-and-tap movements above the icons which are projected on a surface to activate the commands. The capacitive sensing mode is enabled by a handheld, portable device, over which finger movements are detected by capacitive sensors to control the image review. Following initial feedback, light projection and capacitive sensing modes were selected for further testing by comparing with the conventional mode of image interaction in time trials for performing a series of standardized image manipulation tasks. Finally, the usability of the technology platform was examined in actual clinical procedures. RESULTS: The light projection and the capacitive sensing modes were evaluated in the time trials and exhibited 60% and 71% reduction in time, respectively, relative to the control mode (p < 0.001). Clinical feasibility for this platform was demonstrated in three actual interventional radiology cases. CONCLUSION: Accessing, navigating, and extracting relevant information from patient images intraprocedurally are cumbersome and time-consuming tasks that affect safety, efficiency, and decision-making during image-guided procedures. This study demonstrated that the novel technology addressed this issue by allowing touchless interaction with these images in the sterile field.

VirtualDose-IR: a cloud-based software for reporting organ doses in interventional radiology.

A cloud-based software, VirtualDose-IR (Virtual Phantoms Inc., Albany, New York, USA), designed to report organ doses and effective doses for a diverse patient population from interventional radiology (IR) procedures has been developed and tested. This software is based on a comprehensive database of Monte Carlo-generated organ dose built with a set of 21 anatomically realistic patient phantoms. The patient types included in this database are both male and female people with different ages reflecting reference adults, obese people with different BMIs and pregnant women at different gestational stages. Selectable parameters such as patient type, tube voltage, filtration thickness, beam direction, field size, and irradiation site are also considered in VirtualDose-IR. The software has been implemented using the 'Software as a Service (SaaS)' delivery concept permitting simultaneous multi-user, multi-platform access without requiring local installation. The patient doses resulting from different target sites and patient populations were reported using the VirtualDose-IR system. The patient doses under different source to surface distances (SSD) and beam angles calculated by VirtualDose-IR and Monte Carlo simulations were compared. For most organs, the dose differences between VirtualDose-IR results and Monte Carlo results were less than 0.3 mGy at 15 000 mGy * cm2 kerma-area product (KAP). The organ dose results were compared with measurement data previously reported in literatures. The doses to organs that were located within the irradiation field match closely with experimental measurement data. The differences in the effective dose values between calculated using VirtualDose-IR and those measured were less than 2.5%. The dose errors of most organs between VirtualDose-IR and literature results were less than 40%. These results validate the accuracy of organ doses reported by VirtualDose-IR. With the inclusion of pre-specified clinical IR examination parameters (such as beam direction, target location, field of view and beam quality) and the latest anatomically realistic patient phantoms in Monte Carlo simulations, VirtualDose-IR provides users with accurate dose information in order to systematically compare, evaluate, and optimize IR plans.

Evaluation of three-dimensional iterative image reconstruction in C-arm-based interventional cone-beam CT: A phantom study in comparison with customary reconstruction technique.

We compared images obtained using a three-dimensional iterative image reconstruction (3D-IIR) algorithm for C-arm-based interventional cone-beam computed tomography (CBCT) with that using the customary reconstruction technique to quantify the effect of reconstruction techniques on image quality.We scanned 2 phantoms using an angiography unit with digital flat-panel system-an elliptical cylinder acrylic phantom to evaluate spatial resolution and a Catphan phantom to evaluate CT number linearity, image noise, and low-contrast resolution. Three-dimensional imaging was calculated using Feldkamp algorithms, and additional image sets were reconstructed using 3D-IIR at 5 settings (Sharp, Default, Soft+, Soft++, Soft+++). We evaluated quality of images obtained using the 6 reconstruction techniques and analyzed variance to test values of the 10% value of each MTF, mean CT number, and contrast-to-noise ratio (CNR), with P < .05 considered statistically significant.Modulation transfer function curves and CT number linearity among images obtained using the customary technique and the 5 3D-IIR techniques showed excellent agreement. Noise power spectrum curves demonstrated uniform noise reduction across the spatial frequency in the iterative reconstruction, and CNR obtained using all but the Sharp 3D-IIR technique was significantly better than that using the customary reconstruction technique (Sharp, P = .1957; Default, P = .0042; others, P < .0001). Use of 3D-IIR, especially the Soft++ and Soft+++ settings, improved visualization of low-contrast targets.Use of a 3D-IIR can significantly improve image noise and low-contrast resolution while maintaining spatial resolution in C-arm-based interventional CBCT, yielding higher quality images that may increase safety and efficacy in interventional radiology.

Tools for Simulation; Low Budget and No Budget.

Interventional Radiology (IR) incorporates a unique set of technical skills such as ultrasound-guided needle placement, inferior vena cava filter placement, and wire/catheter exchange, which are not easily attained in other aspects of medical training. Simple, low cost models can allow medical students and residents to attain these skills in a low risk setting. These simulated tasks will ultimately combine to improve preparedness of trainees during patient procedures allowing them to advance more quickly through the training paradigm without patient risk. Many commercially available devices may be cost prohibitive, so low cost solutions are presented.

Reduction of Operator Hand Exposure in Interventional Radiology With a Novel Finger Sack Using Tungsten-containing Rubber.

The purpose of this study was to evaluate the x-ray shielding ability of a novel tungsten-particle-containing rubber-based finger sack for use in interventional radiology. Shielding rates for the air kerma (mGy m) were measured using a semiconductor dosimeter with and without the finger sack and commercial lead gloves, at a 20 cm distance from the field of view. A C-arm digital angiography system was used with x-ray tube voltages of 60, 80, 100, and 120 kVp. In addition, the 70 µm dose equivalent to the operator's finger was measured using fluorescent glass dosimeters with and without the finger sack during interventional radiology examinations. The x-ray shielding rates for 60, 80, 100, and 120 kV x rays were 98.0 ± 0.03%, 94.8 ± 0.05%, 92.3 ± 0.12%, and 90.1 ± 0.03%, respectively, with the finger sack and 69.8 ± 0.39%, 61.0 ± 0.53%, 52.3 ± 0.52%, and 47.0 ± 0.69% with the lead gloves. The x-ray shielding rates for the fluoroscopy and cine mode with the finger sack were 91.3 ± 0.21% and 56.5 ± 0.58%, respectively, while with the lead gloves they were 96.5 ± 0.04% and 67.6 ± 0.33%. The 70 µm dose equivalent for the operator's finger exposure dose was reduced by approximately 39.4% using the finger sack. The finger shields were more user friendly, had excellent radiation shielding ability against x rays, and should reduce finger exposure in interventional radiology.