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1.
Br J Radiol ; 94(1117): 20190878, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33090887

RESUMO

OBJECTIVE: Mini C-arm fluoroscopes are widely used by orthopaedic surgeons for intraoperative image guidance without the need for radiographers. This puts the responsibility for radiation exposure firmly with the operating surgeon. In order to maintain safe and best practice under U.K. Ionising Radiation (Medical Exposure) Regulations, one must limit radiation exposure and audit performance using national diagnostic reference levels (DRLs). In the case of the mini C-arm, there are no national DRLs. IR(ME)R, therefore, require the establishment of local DRLs by each hospital to act as an alternative guideline for safe radiation use. The aim of our audit was to establish local DRLs based on our experience operating with the use of the mini C-arm over the last 7 years. METHODS: This retrospective audit evaluates the end dose-area product (DAP) recorded for common trauma and orthopaedic procedures using the mini C-arm in a busy district general hospital.We present the quartile data and have set the cut-off point as the third quartile for formulating the local DRLs, consistent with the methodology for the conventional fluoroscope. RESULTS: For our data set (n = 1664), the third quartile DAP values were lowest for surgeries to the forearm (5.38 cGycm2), hand (7.62 cGycm2), and foot/ankle (8.56 cGycm2), and highest for wrist (10.64 cGycm2) and elbow (14.61 cGycm2) procedures. ADVANCES IN KNOWLEDGE: To our knowledge, this is the largest data set used to establish local DRLs. Other centres may find our guidelines useful whilst they establish their own local DRLs.


Assuntos
Procedimentos Ortopédicos , Doses de Radiação , Exposição à Radiação/estatística & dados numéricos , Radiografia Intervencionista/instrumentação , Radiografia Intervencionista/métodos , Fluoroscopia/instrumentação , Fluoroscopia/métodos , Humanos , Cuidados Intraoperatórios/métodos , Valores de Referência , Estudos Retrospectivos , Reino Unido
2.
Medicine (Baltimore) ; 99(43): e22895, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33120838

RESUMO

BACKGROUND: Traditionally, S1 transforaminal epidural steroid injection (TFESI) has been performed using an anteroposterior (AP) fluoroscopic view. In 2007, the oblique "Scotty dog" (OS) approach was introduced as an alternative technique. We compared passage time of the needle into S1 foramen (Tf) between the anteroposterior (AP) and oblique "Scotty dog" (OS) approach during S1 TFESI. METHODS: In this prospective randomized controlled trial, seventy patients scheduled S1 TFESI were randomly allocated into AP or OS groups. In the AP group, a slight cephalad-caudad tilt was used. In the OS group, the C-arm was rotated ipsilateral oblique degrees to view the S1 Scotty dog. Both groups received injection of steroid mixed with local anesthetics. We measured the passage time of the needle into S1 foramen (Tf), primary outcome, and total procedure time (Tt) between the groups. We also recorded presence of intravascular injection, patients-assessed pain relief for one month and complications. RESULTS: The Tf and Tt were shorter in the OS than in the AP group (24.4 ±â€Š24.0 s vs 47. 8 ±â€Š53.2seconds; 93.3 ±â€Š35.0 seconds vs 160.0 ±â€Š98.7 seconds, P < .001, both). Incidence of intravascular injection (AP, 8 [22.8%]; OS, 4 [11.4%], P = .205), pain score, and complication rates were not statistically different between the two groups. In logistic regression analysis, the body mass index (BMI) was a risk factor for longer Tt (odds ratio [OR] = 1.27, 95% CI: 1.02-1.58, P = .030). CONCLUSION: The passage time of the needle into S1 foramen was shorter in OS approach and the OS approach reduced the procedure time compared with the AP approach during S1 TFESI. The practitioners should note that procedure time can be prolonged in obese patients.


Assuntos
Fluoroscopia/instrumentação , Injeções Epidurais/métodos , Erros Médicos/efeitos adversos , Radiculopatia/terapia , Esteroides/administração & dosagem , Administração Intravenosa/estatística & dados numéricos , Idoso , Anestésicos Locais/administração & dosagem , Índice de Massa Corporal , Feminino , Humanos , Incidência , Injeções Epidurais/efeitos adversos , Região Lombossacral/diagnóstico por imagem , Região Lombossacral/fisiopatologia , Masculino , Pessoa de Meia-Idade , Agulhas/efeitos adversos , Medição da Dor/métodos , Estudos Prospectivos , República da Coreia/epidemiologia , Distúrbios Somatossensoriais/psicologia , Fatores de Tempo
3.
PLoS One ; 15(9): e0239114, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956379

RESUMO

BACKGROUND: In recent years, transbronchial cryobiopsy (TBCB) has come to be increasingly used in interventional pulmonology units as it obtains larger and better-quality samples than conventional transbronchial lung biopsy (TBLB) with forceps. No multicenter studies have been performed, however, that analyse and compare TBCB and TBLB safety and yield according to the interstitial lung disease (ILD) classification. OBJECTIVES: We compared the diagnostic yield and safety of TBCB with cryoprobe sampling versus conventional TBLB forceps sampling in the same patient. METHOD: Prospective multicenter clinical study of patients with ILD indicated for lung biopsy. Airway management with orotracheal tube, laryngeal mask and rigid bronchoscope was according to the protocol of each centre. All procedures were performed using fluoroscopy and an occlusion balloon. TBLB was followed by TBCB. Complications were recorded after both TBLB and TBCB. RESULTS: Included were 124 patients from 10 hospitals. Airway management was orotracheal intubation in 74% of cases. Diagnostic yield according to multidisciplinary committee results for TBCB was 47.6% and for TBLB was 19.4% (p<0.0001). Diagnostic yield was higher for TBCB compared to TBLB for two groups: idiopathic interstitial pneumonias (IIPs) and ILD of known cause or association (OR 2.5; 95% CI: 1.4-4.2 and OR 5.8; 95% CI: 2.3-14.3, respectively). Grade 3 (moderate) bleeding after TBCB occurred in 6.5% of patients compared to 0.8% after conventional TBLB. CONCLUSIONS: Diagnostic yield for TBCB was higher than for TBLB, especially for two disease groups: IIPs and ILD of known cause or association. The increased risk of bleeding associated with TBCB confirms the need for safe airway management and prophylactic occlusion-balloon use. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT02464592.


Assuntos
Broncoscopia/instrumentação , Criocirurgia/instrumentação , Fluoroscopia/instrumentação , Doenças Pulmonares Intersticiais/diagnóstico , Hemorragia Pós-Operatória/epidemiologia , Idoso , Biópsia/efeitos adversos , Biópsia/instrumentação , Biópsia/métodos , Broncoscopia/efeitos adversos , Broncoscopia/métodos , Broncoscopia/estatística & dados numéricos , Criocirurgia/efeitos adversos , Criocirurgia/métodos , Feminino , Fluoroscopia/efeitos adversos , Fluoroscopia/métodos , Humanos , Pulmão/patologia , Doenças Pulmonares Intersticiais/patologia , Masculino , Pessoa de Meia-Idade , Hemorragia Pós-Operatória/etiologia , Estudos Prospectivos
4.
Orthopade ; 49(8): 724-731, 2020 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-32112224

RESUMO

BACKGROUND: A proven and frequently used surgical procedure in patients with idiopathic scoliosis (IS) is posterior transpedicular corrective spondylodesis using the freehand technique. Novel procedures with fluoroscopically and computed tomography (CT)-assisted navigation are presumed to be less risky and more accurate. OBJECTIVE: Is the freehand technique for IS safe with respect to screw-associated complications and intraoperative radiation exposure? MATERIAL AND METHODS: Prospectively collected data (2017-2018) from 39 consecutive patients (average age 18.7 years) with thoracic single curvature IS (61.7°â€¯± 13.9°) from a specialized scoliosis center were evaluated for the following parameters (mean ± standard deviation): total radiation product, fluoroscopy time, fused segments, operative time, blood loss and screw-associated complications. A comparison with data from the literature on intraoperative radiation exposure using navigation procedures was carried out. RESULTS: The total radiation product per patient was 71.7 ± 44.0 cGy*cm2, fluoroscopy time 17.4 ± 8.6 s. (7.8 segments), operative time 183.5 ± 54.2 min and blood loss 379.5 ± 183 ml. There were no screw-associated complications in the entire collective. Correction of the main curvature was 75.7%. Comparison of the data with index data from the literature showed a 1.25-12.5-fold higher radiation exposure for patients with fluoroscopically assisted navigation and 9.25-12.3-fold higher radiation exposure with CT-assisted procedures compared to the present results. CONCLUSION: The results of this study showed that with appropriate experience freehand positioning of pedicle screws is associated with comparable accuracy and less radiation exposure for patients than navigation procedures. With respect to the young age of patients, a radiation-induced long-term risk for malignant diseases should be taken into consideration.


Assuntos
Fluoroscopia/instrumentação , Parafusos Pediculares , Escoliose/cirurgia , Fusão Vertebral , Cirurgia Assistida por Computador/instrumentação , Tomografia Computadorizada por Raios X/instrumentação , Adolescente , Fluoroscopia/métodos , Humanos , Exposição à Radiação , Cirurgia Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem
5.
Sci Rep ; 10(1): 5643, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32221327

RESUMO

Minimally invasive treatment of vascular disease demands dynamic navigation through complex blood vessel pathways and accurate placement of an interventional device, which has resulted in increased reliance on fluoroscopic guidance and commensurate radiation exposure to the patient and staff. Here we introduce a guidance system inspired by electric fish that incorporates measurements from a newly designed electrogenic sensory catheter with preoperative imaging to provide continuous feedback to guide vascular procedures without additional contrast injection, radiation, image registration, or external tracking. Electrodes near the catheter tip simultaneously create a weak electric field and measure the impedance, which changes with the internal geometry of the vessel as the catheter advances through the vasculature. The impedance time series is then mapped to a preoperative vessel model to determine the relative position of the catheter within the vessel tree. We present navigation in a synthetic vessel tree based on our mapping technique. Experiments in a porcine model demonstrated the sensor's ability to detect cross-sectional area variation in vivo. These initial results demonstrate the capability and potential of this novel bioimpedance-based navigation technology as a non-fluoroscopic technique to augment existing imaging methods.


Assuntos
Cateteres , Procedimentos Endovasculares/instrumentação , Animais , Procedimentos Endovasculares/métodos , Desenho de Equipamento/instrumentação , Desenho de Equipamento/métodos , Feminino , Fluoroscopia/instrumentação , Fluoroscopia/métodos , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/métodos , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos , Suínos
6.
Jt Dis Relat Surg ; 31(1): 2-7, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32160486

RESUMO

OBJECTIVES: This study aims to introduce a new low-cost universal laser aiming device (LAD) that can be used in existing C-arm fluoroscopy devices, independent of brand and model, and to determine whether this new universal LAD improves technician accuracy in locating the desired region at the midpoint of the fluoroscopic image. MATERIALS AND METHODS: A low-priced universal LAD that is compatible with existing 12-inch C-arm fluoroscopy devices was designed. Eight radiology technicians with varied levels of experience in C-arm fluoroscopy participated in the study. A 12 mm cortical screw with a diameter of 3.5 mm was placed on proximal, diaphyseal, and distal points of femur, tibia, and humerus bones in the anteroposterior plane on L3 vertebrae and the left pubis arm in the pelvis bone model. Technicians were asked to align each screw in the image center 10 times from a distance of 30 cm in the anterolateral plane, first without the LAD and then with the LAD. The distance of the screw head to the center point was measured from the 3,520 images with the help of medical viewer software based on the X- and Y-axis. RESULTS: Each fluoroscopic image was divided into 48 equal parts and the length of a part was taken as one unit for distance measurements. The compliance between technicians without the LAD was 0.347 (95% confidence interval [CI]: 0.208-0.47, p=0.001) and with the LAD was 0.687 (95% CI: 0.621-0.741, p=0.001). The distance between the screw head and the center of the image without the LAD was 19.0±9.8 for technicians with more than 10 years of experience and 28.0±12.9 for those with less than 10 years of experience. This difference was statistically significant (p=0.001). When the LAD was used, the difference between the less experienced (3.1±1.5) and more experienced (3.3±2.0) technicians was statistically reduced, along with the distance (p=0.033). CONCLUSION: The use of the LAD with C-arm fluoroscopy appears to be successful in helping technicians capture the desired point in the center of the fluoroscopic image. The use of the LAD reduces the experience gap between technicians.


Assuntos
Fluoroscopia , Lasers , Vértebras Lombares/diagnóstico por imagem , Intensificação de Imagem Radiográfica , Parafusos Ósseos , Desenho de Equipamento , Fluoroscopia/instrumentação , Fluoroscopia/métodos , Humanos , Cuidados Intraoperatórios/instrumentação , Cuidados Intraoperatórios/métodos , Procedimentos Ortopédicos/instrumentação , Procedimentos Ortopédicos/métodos , Procedimentos Ortopédicos/normas , Ossos Pélvicos/diagnóstico por imagem , Intensificação de Imagem Radiográfica/instrumentação , Intensificação de Imagem Radiográfica/métodos
7.
Surg Innov ; 27(1): 88-100, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31514682

RESUMO

Purpose. We analyzed the literature to determine (1) the surgically relevant applications for which head-mounted display (HMD) use is reported; (2) the types of HMD most commonly reported; and (3) the surgical specialties in which HMD use is reported. Methods. The PubMed, Embase, Cochrane Library, and Web of Science databases were searched through August 27, 2017, for publications describing HMD use during surgically relevant applications. We identified 120 relevant English-language, non-opinion publications for inclusion. HMD types were categorized as "heads-up" (nontransparent HMD display and direct visualization of the real environment), "see-through" (visualization of the HMD display overlaid on the real environment), or "non-see-through" (visualization of only the nontransparent HMD display). Results. HMDs were used for image guidance and augmented reality (70 publications), data display (63 publications), communication (34 publications), and education/training (18 publications). See-through HMDs were described in 55 publications, heads-up HMDs in 41 publications, and non-see-through HMDs in 27 publications. Google Glass, a see-through HMD, was the most frequently used model, reported in 32 publications. The specialties with the highest frequency of published HMD use were urology (20 publications), neurosurgery (17 publications), and unspecified surgical specialty (20 publications). Conclusion. Image guidance and augmented reality were the most commonly reported applications for which HMDs were used. See-through HMDs were the most commonly reported type used in surgically relevant applications. Urology and neurosurgery were the specialties with greatest published HMD use.


Assuntos
Realidade Aumentada , Cirurgia Assistida por Computador , Realidade Virtual , Desenho de Equipamento , Fluoroscopia/instrumentação , Humanos , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos
8.
AJNR Am J Neuroradiol ; 41(1): 183-188, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31831464

RESUMO

Patients with spinal muscular atrophy often have complete interlaminar osseous fusion, precluding lumbar puncture via the standard interlaminar approach. Recently, we have developed a new coaxial curved-needle variation of fluoroscopy-guided transforaminal lumbar puncture for intrathecal injections in this patient population. Between October 2017 and November 2018, fifty-nine consecutive transforaminal lumbar punctures using this technique were performed in 12 patients with spinal muscular atrophy for intrathecal nusinersen injection, with a 100% technical success rate and no C1-2 punctures required. One major complication occurred, consisting of a post-dural puncture headache, which required a therapeutic transforaminal epidural blood patch. Two minor complications occurred, both of which involved inadvertent puncture of a dorsal muscular arterial branch, without clinical sequelae. A fluoroscopy-guided curved-needle transforaminal approach is an effective technique for lumbar puncture in difficult cases, such as in this cohort of patients with spinal muscular atrophy and complete interlaminar osseous fusion undergoing intrathecal nusinersen injections.


Assuntos
Injeções Espinhais/instrumentação , Atrofia Muscular Espinal/tratamento farmacológico , Agulhas , Oligonucleotídeos/administração & dosagem , Radiografia Intervencionista/instrumentação , Adolescente , Adulto , Criança , Feminino , Fluoroscopia/instrumentação , Fluoroscopia/métodos , Humanos , Injeções Espinhais/métodos , Masculino , Atrofia Muscular Espinal/patologia , Radiografia Intervencionista/métodos , Adulto Jovem
9.
Radiol Phys Technol ; 12(4): 393-400, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31691889

RESUMO

Recently, there has been a significant amount of interest in studying the importance of radiation doses to the eye lens during endoscopic retrograde cholangiopancreatography (ERCP). A study that focused on measuring the scattered radiation using an ionization chamber survey meter reported that a lead curtain was useful in reducing the scattered radiation. The over-couch X-ray tube system tends to deliver higher doses to the head and neck of the staff involved in the procedure than the under-couch X-ray tube position. In this study, a small optically stimulated luminescence (OSL) dosimeter called the nanoDot was used to evaluate and measure the amount of radiation; this dosimeter was developed by Landauer Ltd. and was specifically designed for point measurements. There are numerous studies that have reported the usefulness of personal OSL dosimeters other than the nanoDot to measure scattered radiation. Here, we evaluated the amount of scattered radiation, along with the degree of reduction achieved with the use of a protective curtain, while employing a personal OSL dosimeter and nanoDot. When the scattered radiation dose was measured using the nanoDot, the maximum recorded value without a protective curtain was 0.363 mGy and that with a protective curtain was 0.026 mGy, both at the height of 100 cm. The maximum reduction rate of scattered radiation while using a protective curtain was approximately 93% and 97% at 100 cm and 150 cm, respectively. The measured values recorded using both personal OSL dosimeters and nanoDot machine were strongly correlated.


Assuntos
Fluoroscopia/instrumentação , Dosimetria por Luminescência Estimulada Opticamente , Espalhamento de Radiação , Humanos , Exposição Ocupacional/prevenção & controle , Doses de Radiação , Proteção Radiológica/instrumentação
10.
Radiography (Lond) ; 25(4): 301-307, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31582236

RESUMO

INTRODUCTION: Smart glasses can be adapted to display radiographic images to allow clinician's gaze not to be directionally fixed or predetermined by computer monitor location. This study presents an analysis of eye lens dose during interventional fluoroscopy guided procedures, comparing fixed monitor positions against the use of smart glasses. METHODS: Using a head phantom (simulating the clinician), thermoluminescent dosimeters and lead shielded glasses, the dose to the eye was measured for different head 'rotations and tilts' for: gaze directed towards the main scattering source (patient/primary beam) to represent potential gaze direction if smart glasses are used; gaze directed to a range of potential computer monitor positions. An anthropomorphic pelvis phantom was utilised to simulate the patient. Accumulated dose rates (µGy s-1) from five 10-second exposures at 75 kV 25.2 mAs were recorded. RESULTS: An average DAP reading of 758.84 cGy cm2 was measured during each 10 second exposure. Whilst wearing lead shielded glasses a 6.10 - fold reduction in dose rate to the lens is possible (p < 0.05). Influence of the direction of gaze by the clinician demonstrated a wide range of dose rate reduction from 3.13% (p = 0.16) to 143.69% (p < 0.05) when the clinician's gaze was towards the main scattering source. Increased dose rate to the clinician's eyes was received despite wearing lead shielded glasses, as the angle of gaze moved 45° and 90° from 0°. CONCLUSION: If the clinician's gaze is directed towards the main scattering source a potential exists for reducing eye lens dose compared with fixed location computer monitors. Introduction of lead lined smart glasses into interventional radiology may lead to improvements in patient care, reducing the need for the clinician to look away from the patient to observe a radiographic image.


Assuntos
Realidade Aumentada , Fluoroscopia/instrumentação , Proteção Radiológica/instrumentação , Radiografia Intervencionista/instrumentação , Óculos Inteligentes , Olho/efeitos da radiação , Feminino , Fluoroscopia/efeitos adversos , Fluoroscopia/métodos , Humanos , Masculino , Imagens de Fantasmas , Exposição à Radiação/prevenção & controle , Exposição à Radiação/estatística & dados numéricos , Radiografia Intervencionista/efeitos adversos , Radiografia Intervencionista/métodos , Dosimetria Termoluminescente
11.
Med Phys ; 46(11): 4918-4922, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31437308

RESUMO

PURPOSE: The goal of this study was to investigate x-ray beam profiles at various water depths to characterize the two-dimensional x-ray dose distribution, allowing for off-axis and out-of-field radiation dose estimation for a wide range of x-ray beam spectra commonly encountered in fluoroscopically guided interventional procedures. METHODS: A Siemens Artis interventional fluoroscope was operated in a service mode to generate a continuous x-ray beam at fixed x-ray beam spectra, defined by their kVp and the thickness of additional copper filtration. A PTW scanning water tank with a diode detector was used to measure the x-ray beam profiles at several depths in water at various fields of view and x-ray beam spectra, both parallel and perpendicular to the anode-cathode axis direction. RESULTS: X-ray beam profiles, including out-of-field tails, were characterized for a wide range of beam qualities. The anode heel effect was pronounced even at depth, resulting in large dose variations across the x-ray field; this effect was even more definite at large fields of view, at higher kVps, and in the absence of additional copper filtration. CONCLUSIONS: This study investigated and characterized 2D radiation dose deposition in water from x-ray beam spectra commonly used by modern fluoroscopes in interventional procedures. This knowledge can be applied to manual dosimetry calculations or can be used to refine the accuracy of automated dose mapping tools or Monte Carlo simulations of the radiation dose to soft tissue within the x-ray field and to tissue adjacent to the primary beam. Additionally, this study illustrates a substantial reduction of the anode heel effect by using moderate amounts of additional copper filtration to harden the x-ray beam spectrum.


Assuntos
Cobre , Fluoroscopia/métodos , Doses de Radiação , Filtração , Fluoroscopia/instrumentação , Método de Monte Carlo , Radiometria , Raios X
12.
J Orthop Trauma ; 33(12): e471-e474, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31343598

RESUMO

OBJECTIVE: Fluoroscopy is used in many orthopaedic procedures. The C-Arm drape is known to be easily contaminated during orthogonal imaging. However, it is unknown if one area of the operative field is more prone to contamination than another. The purpose of this study was to determine if secondary transfer of contaminate from the undraped portion of the C-Arm occurs. METHODS: A C-Arm was utilized with standardized draping in a simulated operating room. We used a simulated contaminant: a fluorescent powder that phosphoresces under ultraviolet light. The powder was placed over nonsterile portions. A darkened room with a black light, and a camera was used. C-Arm movements were simulated by cycling through lateral to Anteroposterior imaging. Images were taken before (control) and after cycles of orthogonal imaging. The change in light intensity was quantified at each time point over each area as a percentage of change. RESULTS: Contamination of the surgical field was observed in all areas after 15 cycles, with the area adjacent to the C-Arm being most pronounced. A linear increase in intensity with increased cycles was observed (R = 0.297; P = 0.036), with the mean increase in intensity of 5% after 15 cycles (95% confidence interval, 1.97-7.86). The remaining areas (closest to surgeon and middle) showed an increase as well but were not significant (P > 0.05). CONCLUSIONS: Secondary contamination of the surgical field from the C-Arm occurs. The area most prone to contamination is the area immediately adjacent to the fluoroscopy unit, usually opposite the surgeon.


Assuntos
Contaminação de Equipamentos/prevenção & controle , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Fluoroscopia/instrumentação , Procedimentos Ortopédicos/instrumentação , Humanos , Modelos Anatômicos , Modelos Biológicos
13.
PLoS One ; 14(7): e0219174, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31260497

RESUMO

The primary mode of visualization during transcatheter procedures for structrural heart disease is fluoroscopy, which suffers from low contrast and lacks any depth perception, thus limiting the ability of an interventionalist to position a catheter accurately. This paper describes a new image guidance system by utilizing augmented reality to provide a 3D visual environment and quantitative feedback of the catheter's position within the heart of the patient. The real-time 3D position of the catheter is acquired via two fluoroscopic images taken at different angles, and a patient-specific 3D heart rendering is produced pre-operatively from a CT scan. The spine acts as a fiduciary land marker, allowing the position and orientation of the catheter within the heart to be fully registered. The automated registration method is based on Fourier transformation, and has a high success rate (100%), low registration error (0.42 mm), and clinically acceptable computational cost (1.22 second). The 3D renderings are displayed and updated on the augmented reality device (i.e., Microsoft HoloLens), which can provide pre-set views of various angles of the heart using voice-command. This new image-guidance system with augmented reality provides a better visualization to interventionalists and potentially assists them in understanding of complicated cases. Furthermore, this system coupled with the developed 3D printed models can serve as a training tool for the next generation of cardiac interventionalists.


Assuntos
Realidade Aumentada , Cateterismo Cardíaco/métodos , Procedimentos Cirúrgicos Cardíacos/métodos , Imageamento Tridimensional/métodos , Cirurgia Assistida por Computador/métodos , Cateterismo Cardíaco/instrumentação , Procedimentos Cirúrgicos Cardíacos/instrumentação , Cateteres , Marcadores Fiduciais , Fluoroscopia/instrumentação , Fluoroscopia/métodos , Análise de Fourier , Coração/anatomia & histologia , Coração/diagnóstico por imagem , Humanos , Imageamento Tridimensional/instrumentação , Modelos Anatômicos , Planejamento de Assistência ao Paciente , Imagens de Fantasmas , Cuidados Pré-Operatórios/métodos , Impressão Tridimensional , Coluna Vertebral/diagnóstico por imagem , Cirurgia Assistida por Computador/instrumentação , Tomografia Computadorizada por Raios X
14.
Arch Orthop Trauma Surg ; 139(11): 1579-1586, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31278509

RESUMO

INTRODUCTION: When locking intramedullary nails, inserting the distal interlocking screw accurately and quickly with less radiation exposure is very important. The purpose of this randomized control study was to compare radiation exposure and accuracy of distal locking screws between free-hand fluoroscopic guidance and the use of a distal targeting system (DTS). MATERIALS AND METHODS: Inclusion criteria of this study were patients older than 60 years who need an intramedullary nailing due to unstable intertrochanteric and subtrochanteric fracture. The primary outcome was the attempt numbers of image intensifier during the insertion of distal locking screws. Secondary outcomes were operative time and angles between distal locking screws and nail. RESULTS: A total of 36 patients participated in the study. Eighteen patients using free-hand fluoroscopic guidance were assigned to Group I while 18 patients using DTS were assigned to Group II. The number of attempts of image intensifier during distal screw insertion (57.3 ± 31.42 vs. 11.5 ± 7.41, p < 0.001), ratio of attempt number for distal screws to the total attempts (0.33 ± 0.21 vs. 0.12 ± 0.08, p = 0.001), the number of hand exposure to image intensifier directly (75.0 ± 29.55 vs. 13.5 ± 19.07, p < 0.001), and the time of radiation exposure during distal screws insertion (42.57 ± 2.42 s vs. 12.72 ± 8.10 s, p < 0.001) were significantly lower in Group II compared to those in Group I. And, operation time (96.3 min ± 18.94 vs. 76.1 min ± 14.10, p < 0.001) was also statistically significantly lower in Group II. Both distal locking screws were significantly closer to perpendicular direction to the nail in Group II. CONCLUSION: The attempt number of image intensifier during the insertion of two distal locking screws was significantly reduced with DTS compared with that with free hand fluoroscopic guidance. Angle between distal locking screws and nail was also more accurate using DTS.


Assuntos
Fluoroscopia , Fixação Intramedular de Fraturas , Exposição à Radiação/estatística & dados numéricos , Cirurgia Assistida por Computador , Fluoroscopia/instrumentação , Fluoroscopia/métodos , Fluoroscopia/estatística & dados numéricos , Fixação Intramedular de Fraturas/instrumentação , Fixação Intramedular de Fraturas/métodos , Fixação Intramedular de Fraturas/estatística & dados numéricos , Humanos , Período Intraoperatório , Pessoa de Meia-Idade , Duração da Cirurgia , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos , Cirurgia Assistida por Computador/estatística & dados numéricos
15.
Medicine (Baltimore) ; 98(26): e16197, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31261562

RESUMO

The aim of this study was to evaluate the clinical feasibility and effectiveness of bedside peripherally inserted central catheter (PICC) using portable digital radiography (DR) in intensive care unit (ICU) patients.Sixty-five ICU patients who underwent PICC were enrolled in this study between May 2016 and May 2017. Of these 65 patients, 45 (69.2%) underwent the procedures bedside in ICU using portable DR, and 20 (30.8%) underwent the procedures at the intervention clinic, both performed by a single interventional radiologist. We retrospectively reviewed electronic medical records for clinical presentation, total procedural time, total radiation dose, total patient transfer time, and clinical outcomes. We performed an independent t test to compare the clinical effectiveness between the 2 groups.The technical and clinical success rates were 100% in both groups, and there were no procedure-related complications. The total radiation dose of bedside PICC at ICU was significantly lower than that of conventional PICC at the intervention clinic (557.9 mGy*cm ± 209.2 vs 985.2 mGy*cm ± 547.6, P < .001). The total procedure time was significantly different between the bedside and conventional PICC groups (26.8 minutes ± 3.9 vs 24.1 minutes ± 5.55, P = .028). The average patient transfer time to the intervention clinic was 26.6 minutes ± 9.8.Bedside PICC using portable DR is a safe and effective procedure option to manage ICU patients in daily clinical practice.


Assuntos
Cateterismo Periférico/instrumentação , Cuidados Críticos , Sistemas Automatizados de Assistência Junto ao Leito , Radiografia Intervencionista/instrumentação , Idoso , Cateterismo Periférico/métodos , Cuidados Críticos/métodos , Estudos de Viabilidade , Feminino , Fluoroscopia/instrumentação , Fluoroscopia/métodos , Humanos , Masculino , Transferência de Pacientes , Doses de Radiação , Radiografia Intervencionista/métodos , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
16.
Phys Med Biol ; 64(13): 135012, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31158823

RESUMO

Simultaneous acquisition of nuclear and fluoroscopic projections could be of benefit for image-guided radionuclide administration. A gamma camera positioned behind an x-ray flat panel detector can accomplish such simultaneous acquisition, but the gamma camera performance suffers from the intense x-ray dose. A regular NaI(Tl)-based camera has nominal performance up to 0.02 nGy dose per pulse, whereas 10 nGy dose is expected for our foreseen applications. We evaluated the performance of CeBr3- and CZT-based detectors and investigated a cost-effective improvement of a regular NaI(Tl)-based camera by the introduction of a high-pass filter and shorting circuit. A CeBr3-based detector was exposed to 5 mGy x-ray dose and the resulting light emission was measured over time to quantify the crystal afterglow, allowing comparison with a previously measured NaI(Tl)-based detector. The NaI(Tl)-, CeBr3- and CZT-based detectors were exposed to x-ray pulse sequences with dose from 0.06 to 60 nGy, while being irradiated with a gamma source. The mean gamma energy and energy resolution in between the x-ray pulses were measured as a reference of the detector performance. The afterglow signal after 3 ms was 14.1% for the NaI(Tl)-based detector, whereas for the CeBr3-based detector it was only 0.1%. The limits for a proper functioning detectors are 0.32 nGy for the NaI(Tl)-based detector with high-pass filter and shorting circuit and 18.94 nGy for the one with CeBr3. No energy degradation was observed for the CZT module in the studied dose range. The performance of regular NaI(Tl)-based gamma cameras deteriorates when exposed to high x-ray doses. CeBr3 and CZT are much better suited for introduction into a dual-layer detector but have high associated costs. Addition of a high-pass filter and shorting circuit into the PMT of a NaI(Tl)-based detector is a cost-effective solution that works well for low dose levels.


Assuntos
Cádmio , Cério/química , Fluoroscopia/instrumentação , Telúrio , Tálio , Zinco , Desenho de Equipamento , Fatores de Tempo
17.
J Endourol ; 33(9): 691-695, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31161786

RESUMO

Introduction: The widespread use of diagnostic and therapeutic ionizing radiation raises concerns regarding excessive occupational and patient exposure. In this study, we test a novel fluoroscopic technique that has the potential to minimize radiation dose during urologic procedures. Materials and Methods: A prospective evaluation of all patients undergoing endoscopic urologic procedures in our institution was conducted. A "two-point technique (TPT)" is described in which the fluoroscope image intensifier (c-arm) is shifted between caudal and cephalad set points of the operative field. We wished to determine whether patient radiation exposure was lower with TPT than with a non-structured conventional technique, referred to as the cognitive fluoroscopic technique (CFT), in which the manipulation of the c-arm was at the discretion of the user. We obtained all clinical, radiographic, and fluoroscopic data of patients in the study period and used unpaired nonparametric statistical analysis of univariates entered stepwise into a logistic regression model. Results: A total of 106 endoscopic urologic procedures from January 2016 to November 2018 were reviewed. Forty-four (41.5%) cases were performed using TPT and 62 (58.5%) using CFT. The mean fluoroscopy time of TPT vs CFT was 71.1 (±60.8) seconds vs 104.5 (±91.6) seconds, respectively (p = 0.04), and the mean radiation dose on TPT vs CFT was 11.6 (±10.6) mGy vs 20.3 (±24.3) mGy, respectively (p = 0.03). TPT was an independent predictor of reduced operative room (OR) time and fluoro time (p < 0.05), while body mass index, age, and operator were not. Conclusion: The "TPT" helps reducing radiation dose and fluoroscopic time during endoscopic urologic procedures. The TPT is useful to lower radiation exposure to patients and OR staff.


Assuntos
Endoscopia/métodos , Fluoroscopia/instrumentação , Fluoroscopia/métodos , Urologia/instrumentação , Urologia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Doses de Radiação , Exposição à Radiação , Análise de Regressão , Adulto Jovem
18.
Med Phys ; 46(7): 3235-3244, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31059124

RESUMO

PURPOSE: To evaluate markerless tumor tracking (MTT) using fast-kV switching dual-energy (DE) fluoroscopy on a bench top system. METHODS: Fast-kV switching DE fluoroscopy was implemented on a bench top which includes a turntable stand, flat panel detector, and x-ray tube. The customized generator firmware enables consecutive x-ray pulses that alternate between programmed high and low energies (e.g., 60 and 120 kVp) with a maximum frame rate of 15 Hz. In-house software was implemented to perform weighted DE subtraction of consecutive images to create an image sequence that removes bone and enhances soft tissues. The weighting factor was optimized based on gantry angle. To characterize this system, a phantom was used that simulates the chest anatomy and tumor motion in the lung. Five clinically relevant tumor sizes (5-25 mm diameter) were considered. The targets were programmed to move in the inferior-superior direction of the phantom, perpendicular to the x-ray beam, using a cos4 waveform to mimic respiratory motion. Target inserts were then tracked with MTT software using a template matching method. The optimal computed tomography (CT) slice thickness for template generation was also evaluated. Tracking success rate and accuracy were calculated in regions of the phantom where the target overlapped ribs vs spine, to compare the performance of single energy (SE) and DE imaging methods. RESULTS: For the 5 mm target, a CT slice thickness of 0.75 mm resulted in the lowest tracking error. For the larger targets (≥10 mm) a CT slice thickness ≤2 mm resulted in comparable tracking errors for SE and DE images. Overall DE imaging improved MTT accuracy, relative to SE imaging, for all tumor targets in a rotational acquisition. Compared to SE, DE imaging increased tracking success rate of small target inserts (5 and 10 mm). For fast motion tracking, success rates improved from 23% to 64% and 74% to 90% for 5 and 10 mm targets inserts overlapping ribs, respectively. For slow moving targets success rates improved from 19% to 59% and 59% to 91% in 5 and 10 mm targets overlapping the ribs, respectively. Similar results were observed when the targets overlapped the spine. For larger targets (≥15 mm) tracking success rates were comparable using SE and DE imaging. CONCLUSION: This work presents the first results of MTT using fast-kV switching DE fluoroscopy. Using DE imaging has improved the tracking accuracy of MTT, especially for small targets. The results of this study will guide the future implementation of fast-kV switching DE imaging using the on-board imager of a linear accelerator.


Assuntos
Fluoroscopia/instrumentação , Neoplasias Pulmonares/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Neoplasias Pulmonares/fisiopatologia , Movimento , Imagens de Fantasmas , Rotação , Software , Fatores de Tempo
19.
AJR Am J Roentgenol ; 213(3): 651-658, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31063421

RESUMO

OBJECTIVE. Compared with open procedures, minimally invasive surgical procedures are associated with increased radiation exposure and long-term health risks. Ultralow radiation imaging coupled with image enhancement and instrument tracking (ULRI-IE/IT) is a new image modifier that allows a computer to show real-time movement of an instrument as it is adjusted, mimicking live fluoroscopy but without continuous radiation production. The purpose of this study was to determine the accuracy and radiation output of ULRI-IE/IT compared with unassisted conventional fluoroscopy in a variety of surgical procedures. MATERIALS AND METHODS. Physicians of various specialties were asked to identify the ideal location for instrumentation in various spinal, orthopedic, pain, and physiatric procedures and then place an instrument in this location in a cadaver both with and without ULRI-IE/IT assistance. Whether ULRI-IE/IT was used was randomly assigned to reduce the impact of learning. Radiation exposure, time to place the instrument, and the number of images required to achieve accurate positioning were recorded for each procedure. These were compared for unassisted and ULRI-IE/IT-assisted fluoroscopy to determine the utility of ULRI-IE/IT in minimally invasive instrumentation. RESULTS. Twenty-three trials of nine procedures by five physicians were completed both with and without assistance of ULRI-IE/IT. The procedures ranged from percutaneous pedicle screw insertion to foramen ovale ablation. Total time to localize the instrument for all 23 cases was 31.2% longer without assistance. Use of ULRI-IE/IT reduced the total number of images per case by 74.8% and radiation exposure by 91.8%. With ULRI-IE/IT, physicians were able to successfully place the instrument in the correct location on the first attempt in 82.6% of trials and in the second attempt in all trials versus a mean of 4.65 images needed for unassisted fluoroscopy. CONCLUSION. Use of ULRI-IE/IT can dramatically reduce radiation output and the number of images acquired and time required to perform fluoroscopic procedures.


Assuntos
Fluoroscopia/instrumentação , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Duração da Cirurgia , Exposição à Radiação , Radiografia Intervencionista/instrumentação , Cirurgia Assistida por Computador/métodos , Cadáver , Humanos , Posicionamento do Paciente
20.
Actas urol. esp ; 43(4): 205-211, mayo 2019. tab
Artigo em Espanhol | IBECS | ID: ibc-181086

RESUMO

Objetivo: Conocer el grado de formación en protección radiológica (PR) de los urólogos españoles que realizan técnicas endourológicas, así como analizar el empleo de medidas de control y protección frente a radiaciones ionizantes. Material y métodos: Encuesta realizada mediante la Plataforma de Investigación de Estudios Multicéntricos (PIEM) a los 1.894 asociados de la Asociación Española de Urología, entre abril y octubre de 2015. El cuestionario comprende 21 preguntas que interrogan sobre la actividad endourológica realizada, la formación en PR y el empleo de medidas protectoras y de dosimetría personal. Se obtuvo un 17% de respondedores, siendo finalmente válidas para análisis 238 encuestas. Resultados: El 63% de los encuestados no tenían ningún tipo de formación en PR, el 25% poseían acreditación de primer nivel y únicamente un 12% de segundo nivel. El empleo de dosimetría de solapa, muñeca y cristalino era realizada por un 57, 27 y 2% de los urólogos, respectivamente. El uso de medidas de protección frente a radiaciones resultó ser insuficiente. El 53% de los urólogos con mayor riesgo de exposición no tenían ninguna formación en PR, un 30% no usaban dosímetro de solapa y un 40% no empleaban ni delantal ni collar tiroideo durante los procedimientos endourológicos. Conclusiones: La formación en PR, el control de dosis y el empleo de medidas de protección frente a radiaciones ionizantes es insuficiente, incluso en aquellos profesionales más expuestos a radiaciones. Es fundamental corregir estas graves deficiencias en PR tanto a nivel individual como de servicios de urología, sociedades científicas y autoridades sanitarias


Objective: To discover the extent of training in radiological protection (RP) of Spanish urologists who perform endourological procedures, and to analyse the use of on ionising radiation control and protection measures. Material and methods: A survey conducted through the Plataforma de Investigación de Estudios Multicéntricos (PIEM) (Multicentre Study Research Platform) on the 1,894 associates of the Spanish Association of Urology, between April and October 2015. The questionnaire comprised 21 questions on endourological activity undertaken, RP training, and the use of protective measures, and personal dosimetry. Seventeen percent responded, and 238 surveys were eventually validated for study. Results: Sixty-three percent of the respondents had received no type of RP training, 25% had first level accreditation, and only 12% second level. Fifty-seven percent, 27%, and 2% of the urologists used flap, wrist and crystalline dosimetry respectively. Use of radiation protection measures was insufficient. Fifty-three percent of the urologists at greatest risk of exposure had had no training in RP, 30% did not use flap dosimetry, and 40% used neither an apron or thyroid collar during the endourological procedures. Conclusions: RP training, dosis monitoring, and the use of ionising radiation protective measures are insufficient, even by practitioners most exposed to radiation. It is essential that these serious shortcomings in RP are corrected, at the level of the individual, in urology departments, scientific societies, and the health authorities


Assuntos
Humanos , Proteção Radiológica/métodos , Urologistas/educação , Radiação Ionizante , Espanha , Fluoroscopia/instrumentação , Proteção Radiológica/estatística & dados numéricos , Proteção Radiológica/normas , Epidemiologia Descritiva , Dosimetria/métodos
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