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PubMed2003

Which one is at risk in intraoperative fluoroscopy? Assistant surgeon or orthopaedic surgeon?

BACKGROUND: Orthopaedic surgeons use intraoperative portable fluoroscopy and roentgenography. The present study was an attempt to find out if there is a difference between the occupational radiation exposure to the orthopaedic surgeon and assistant surgeon in the operating room while using intraoperative fluoroscopy or radiographic control and to measure it. METHODS: During a 3-month period, 107 consecutive operations were monitored for radiation exposure. At monthly intervals, the radiation doses were measured in millirem and recorded. The distance of the orthopaedic surgeon and the assistant surgeon from the X-ray source were noted in every fluoroscopic check. The orthopaedic surgeon was always at a safe distance (more than 90 cm), but the assistant surgeon always stood nearby (10 cm) the X-ray source for positioning of the patient. RESULTS: The radiation exposure according to the badge on the shoulder was consecutively 3, 4, 3 mrem for the orthopaedic surgeon and 20, 19, 22 mrem for the assistant surgeon. The radiation exposure according to the badges on the anaesthetic machine, in the room and under the apron of the orthopaedic surgeon were all zero, whereas the readings of the badge under the apron of the assistant surgeon were 7, 6, 5 mrem consecutively. CONCLUSION: Our findings show that although the radiation exposure during orthopaedic operations is below the recommendations of the European Committee on Radiation Protection, there is a higher risk of exposure for the assistant surgeon. It has to be kept in mind that there could be morphological and functional damage in cells exposed to radiation. Therefore, we should continue to use appropriate shielding precautions in view of the unknown long-term risks.

Film Dosimetry↗
PubMed2004

Radiation risk management during fluoroscopy for interventional pain medicine physicians.

Because of serious radiographic-induced skin injuries that may have been caused by the inappropriate use of fluoroscopy during the performance of radiograph-guided invasive procedures, the US Food and Drug Administration (FDA) issued an advisory in 1994 suggesting that the key to preventing such unfortunate mishaps may be physician education, training, and credentialing in the safe operation of fluoroscopic equipment. The purpose of this article is to familiarize the interventional pain medicine physician with the physics of ionizing radiation and how to limit patient exposure through the optimum setting of tube current and voltage, the use of limited beam-on time, tight collimation, and the elimination of the nonessential use of the magnification mode on a fluoroscopy unit. In addition, the use of personal protection equipment and the knowledge needed to interpret the personal exposure record of each practitioner is discussed. All of this information will assist the interventional pain medicine physician in meeting the recommended FDA training and credentialing requirements.

Fluoroscopy↗
PubMed1991

Fluoroscopy and nasoendoscopy in designing palatal lift prostheses.

Prosthodontists frequently provide prostheses for the management of speech disorders related to palatopharyngeal dysfunction. Optimal prosthetic management of the palatopharyngeal port requires close interaction between the prosthodontist and speech pathologist in the use of videofluoroscopy and videonasoendoscopy for design, placement, and modification of the prosthesis. Function of the palatopharyngeal port during production of controlled samples of connected speech can be observed from multiview fluoroscopy, including lateral and frontal projections. Like fluoroscopy, nasoendoscopy can be used to observe and record function of the palatopharyngeal port during speech. This article provides an overview of the procedures suggested for diagnosing palatopharyngeal disorders. A method for designing and placing a prosthesis to aid in obturating the nasopharynx is also suggested.

Endoscopy↗
PubMed1988

Temporomandibular joint arthrography without fluoroscopy.

An arthrographic technique for the temporomandibular joint that can be performed in a dental surgical room is described. This technique utilizes a dental radiographic unit and extraoral cassettes for visualization of the needle tip in the inferior synovial space for arthrography. The radiographic visualization is combined with tactile discernment of the needle tip on the mandibular condyle. The successful application of these two methods makes fluoroscopy unnecessary. After an initial success rate of 81% (34 of 42 attempts), we have used the technique successfully in more than 100 cases. Most of the problems encountered with this technique can be attributed to initial operator inexperience. This technique is not suggested as a replacement for fluoroscopy. However, it is a convenient, economical technique that can be used in the dental surgical room by trained clinicians when arthrography is indicated to determine meniscal-condylar relationships and meniscal perforations.

Arthrography↗
PubMedDate not supplied

CT-fluoroscopy link-up (CTF): potential for special procedures.

Some interventional radiological procedures call for unrestricted axial vision and monoplanar fluoroscopy at different angles. We have mounted a fluoroscopic image intensifier in front of the gantry of a CT scanner to assess whether the combination would be useful. This link-up has been tested in a variety of situations and, even with the shortcomings of makeshift equipment, the combination filled some gaps in our vision of what is going on inside the patient, especially before an invasive procedure. It also proved useful in the planning of multiple procedures in a single session, especially when they had to be performed under general anesthesia in children or in the management of critical cases. We feel that the possibilities afforded by CTF (computed tomography plus fluoroscopy) need further exploration prior to the construction of purpose-built equipment. The interim information supplied suggests that it will be worth developing.

Biopsy↗
PubMed1996

Perception of detail and greyscale range in X-ray fluoroscopy images captured with a personal computer and frame-grabber.

OBJECTIVE: To assess the dynamic range of radiological images captured with a personal computer frame-grabbing system coupled to an X-ray fluoroscopy machine. METHODS: A 386DX-40 MHz, IBM compatible, computer with an SVGA monochrome graphics subsystem and a 387 co-processor, installed with a Screen Machine frame-grabber and controlled by a program specially written was used. Various systems were examined and the observer's perceptions of the results assessed. RESULTS: The dynamic range available to an ordinary X-ray fluoroscopy system was found to be restricted to about 750 mV. Similar measurements showed that the dynamic range was always restricted to 3/4-1/2 of the full available signal because of a high value of the dark voltage of the TV camera's target on all seven systems measured. The dynamic range of the computer-frame grabber system was found to be significantly wider than the Image Intensifier-TV camera chain but, surprisingly, it was affected by the type of file format used for image storing on disk. Clinical images from a barium meal examination as well as CT images captured after optimisation of the frame-grabber were found to contain large quantities of noise in the first two least significant bit planes making them redundant and limiting the grey levels needed for image display to less than 64. This number was also less than the 80 grey levels that could be discriminated by the human eye on the computer monitor. CONCLUSIONS: It was concluded that 6 bit digitisation would have been sufficient for image capture. The advantages of the wider dynamic range of the frame-grabber and the processing capabilities of the computer were tested for the possibility of improving the perception of detail. However, the results were negative. The limiting spatial resolution measured with a variable density bar pattern at all magnifications was about 0.4 lp/mm lower from that measured directly on the fluoroscopic screen. A detail perception test had the same result. The perception success was significantly lower with the digital images at all but the highest of the exposure rates and despite the use of image processing filters.

Artifacts↗
PubMed1990

Effect of pulsed progressive fluoroscopy on reduction of radiation dose in the cardiac catheterization laboratory.

The increased application of therapeutic interventional cardiology procedures is associated with increased radiation exposure to physicians, patients and technical personnel. New advances in imaging techniques have the potential for reducing radiation exposure. A progressive scanning video system with a standard vascular phantom has been shown to decrease entrance radiation exposure. The effect of this system on reducing actual radiation exposure to physicians and technicians was assessed from 1984 through 1987. During this time, progressive fluoroscopy was added sequentially to all four adult catheterization laboratories; no changes in shielding procedures were made. During this time, the case load per physician increased by 63% and the number of percutaneous transluminal coronary angioplasty procedures (a high radiation procedure) increased by 244%. Despite these increases in both case load and higher radiation procedures, the average radiation exposure per physician declined by 37%. During the same time, the radiation exposure for technicians decreased by 35%. Pulsed progressive fluoroscopy is effective for reducing radiation exposure to catheterization laboratory physicians and technical staff.

Angioplasty, Balloon, Coronary↗
PubMed2005

Quantification of soft tissue artefact in motion analysis by combining 3D fluoroscopy and stereophotogrammetry: a study on two subjects.

BACKGROUND: Soft tissue artefact is the most invalidating source of error in human motion analysis using optoelectronic stereophotogrammetry. It is caused by the erroneous assumption that markers attached to the skin surface are rigidly connected to the underlying bones. The quantification of this artefact in three dimensions and the knowledge of how it propagates to relevant joint angles is necessary for the interpretation of gait analysis data. METHODS: Two subjects, treated by total knee replacement, underwent data acquisition simultaneously with fluoroscopy and stereophotogrammetry during stair climbing, step up/down, sit-to-stand/stand-to-sit, and extension against gravity. The reference 3D kinematics of the femur and tibia was reconstructed from fluoroscopy-based tracking of the relevant prosthesis components. Soft tissue artefact was quantified as the motion of a grid of retro-reflecting makers attached to the thigh and shank with respect to the underlying bones, tracked by optoelectronic stereophotogrammetry. The propagation of soft tissue artefact to knee rotations was also calculated. FINDINGS: The standard deviation of skin marker trajectory in the corresponding prosthesis-embedded anatomical frame was found up to 31 mm for the thigh and up to 21 mm for the shank. The ab/adduction and internal/external rotation angles were the most affected by soft tissue artefact propagation, with root mean square errors up to 192% and 117% of the corresponding range, respectively. INTERPRETATIONS: In both the analysed subjects the proximal thigh showed the largest soft tissue artefact. This is subject- and task-specific. However, larger artefact does not necessarily produce larger propagated error on knee rotations. Propagated errors were extremely critical on ab/adduction and internal/external rotation. These large errors can nullify the usefulness of these variables in the clinical interpretation of gait analysis.

Aged↗
PubMed2005

Advanced multimodal visualisation of clinical gait and fluoroscopy analyses in the assessment of total knee replacement.

Traditional gait and fluoroscopy analysis of human movement are largely utilised but are still limited in registration, integration, synchronisation and visualisation capabilities. The present work exploits the features of a recently developed software tool based on multimodal display (Data Manager developed within the EU-funded project 'Multimod') in an exemplary clinical case. Standard lower limb gait analysis, comprising segment position, ground reaction force and EMG data collection, and three-dimensional fluoroscopy analysis at the replaced joint were performed in a total knee replacement patient while ascending stairs. Clinical information such as X-rays and standard scores were also available. Data Manager was able to import all this variety of data and to structure these in an original hierarchical tree. Bone and prosthesis component models were registered to corresponding marker position data for effective three-dimensional animations. These were also synchronised with corresponding standard video sequences. Animations, video, time-histories of collected and also processed data were shown in various combinations, according to specific interests of the bioengineering and medical professionals expected to observe and to interpret this large amount of data. This software tool demonstrated to be a valuable means to enhance representation and interpretation of measurements coming from human motion analysis. In a single software, a thorough and effective clinical and biomechanical analysis of human motion was performed.

Arthroplasty, Replacement, Knee↗
PubMed2006

A comparison of patient skin doses before and after replacement of a neurointerventional fluoroscopy unit.

AIM: After several embolization patients presented with radiation-induced skin injury in our neuroradiology centre, replacement of the centre's interventional fluoroscopy unit was prioritized. The aims of the present study were to compare the maximum skin dose delivered to each patient by the old and new units, to devise a method of estimating skin dose from the displayed dose-area product and to set local reference doses. MATERIALS AND METHODS: On the old unit, skin dose was measured using thermoluminescent dosimeters on 12 patients undergoing Gugliemi detachable coil embolization. Similar skin dose measurements were undertaken and the dose-area product was recorded for a further 12 patients on the new unit. RESULTS: The maximum skin dose measured on each patient on the old and new units had a mean of 2.2 Gy and 0.47 Gy, respectively, and a maximum of 4.1 Gy and 1.0 Gy, respectively. Maximum dose delivered to patients' skin by the new equipment was less than a quarter of the dose from the old equipment (p < 0.0001). CONCLUSION: The large reductions in skin dose reduced the risk of patients suffering radiation injury and confirmed the validity of replacing ageing interventional fluoroscopy equipment with modern equipment that incorporates dose management systems. As patient skin dose was correlated with dose-area product, local reference dose levels were set in terms of dose-area product; this enabled the operator to monitor the likely maximum patient skin dose during embolization procedures. Other centres could use a similar method to set their own reference doses.

Angiography, Digital Subtraction↗
PubMed2005

Errors in measuring sagittal arch kinematics of the human foot with digital fluoroscopy.

Although fluoroscopy has been used to evaluate motion of the foot during gait, the accuracy and precision of fluoroscopic measures of osseous structures of the foot has not been reported in the literature. This study reports on a series of experiments that quantify the magnitude and sources of error involved in digital fluoroscopic measurements of the medial longitudinal arch. The findings indicate that with a global distortion correction procedure, errors arising from image distortion can be reduced threefold to 0.2 degrees for angular measurements and to 0.1 mm for linear measures. The limits of agreement for repeated angular measures of the calcaneus and first metatarsal were +/-0.5 degrees and +/-0.6 degrees , indicating that measurement error was primarily associated with the manual process of digitisation. While the magnitude of the residual error constitutes about +/-2.5% of the expected 20 degrees of movement of the calcaneus and first metatarsal, out-of-plane rotation may potentially contribute the greatest source of error in fluoroscopic measures of the foot. However, even at the extremes of angular displacement (15 degrees ) reported for the calcaneum during running gait, the root mean square (RMS) error was only about 1 degrees . Thus, errors associated with fluoroscopic imaging of the foot appear to be negligible when compared to those arising from skin movement artefact, which typically range between 1.5 and 4 mm (equating to errors of 2 degrees to 17 degrees for angular measures). Fluoroscopy, therefore, may be a useful technique for analysing the sagittal movement of the medial longitudinal arch during the contact phase of walking.

Biomechanical Phenomena↗
PubMed2005

Rigiflex pneumatic dilation of achalasia without fluoroscopy: a novel office procedure.

BACKGROUND: Pneumatic balloon dilation is the most effective nonsurgical treatment to relieve functional obstruction of the gastroesophageal junction in achalasia. Since its inception, the conventional technique has been performed under direct fluoroscopic control with or without a guidewire. To overcome the impediments of the conventional technique and radiation exposure, we have devised a novel technique of achalasia dilation without fluoroscopy. The aim of the study was to evaluate the efficacy, the safety, and the outcome of the new method. METHODS: Fifty-six patients (34 men, 22 women) (mean age 32 years) with achalasia cardia were subjected, over a span of 2 years, to dilation with a Gruntzig-type (Rigiflex balloon) pneumatic dilator with the new technique. Clinical response and complications were assessed. OBSERVATIONS: Excellent improvement in dysphagia, pain, and regurgitation was observed in 92.9%, 89.3%, and 89.3% patients at 24 hours, 6 weeks, and 6 months after dilation, respectively. The mean time to maneuver the Rigiflex balloon to the antrum was 30 seconds. The procedure was successfully done in all patients, and there were no procedural failures. The mean time of the procedure was 8 minutes. There were no complications or mortality during the study. CONCLUSIONS: Achalasia dilation with this new technique has excellent results and is devoid of the side effects of radiation. It can be done as an office procedure, without the need of a fluoroscopy setup.

Adult↗
PubMed2006

Validation of a low-dose hybrid RSA and fluoroscopy technique: Determination of accuracy, bias and precision.

Analyzing skeletal kinematics with radiostereometric analysis (RSA) following corrective orthopedic surgery allows the quantitative comparison of different implant designs. The purpose of this study was to validate a technique for dynamically estimating the relative position and orientation of skeletal segments using RSA and single plane X-ray fluoroscopy. Two micrometer-based in vitro phantom models of the skeletal segments in the hip and knee joints were used. The spatial positions of tantalum markers that were implanted into each skeletal segment were reconstructed using RSA. The position and orientation of each segment were determined in fluoroscopy images by minimizing the difference between the markers measured and projected in the image plane. Accuracy was determined in terms of bias and precision by analyzing the deviation between the applied displacement protocol and measured pose estimates. Measured translational accuracy was less than 100 microm parallel to the image plane and less than 700 microm in the direction orthogonal to the image plane. The measured rotational error was less than 1 degrees . Measured translational and rotational bias was not statistically significant at the 95% level of confidence. The technique allows real-time kinematic skeletal measurements to be performed on human subjects implanted with tantalum markers for quantitatively measuring the motion of normal joints and different implant designs.

Biomechanical Phenomena↗
PubMed2005

Radiation exposure to the hands from mini C-arm fluoroscopy.

PURPOSE: To quantify the level of radiation exposure to the hands of hand surgeons using intraoperative mini C-arm fluoroscopy and to compare the actual level of exposure with predicted levels and acceptable limits. METHODS: Five hand surgeons were given ring dosimeters to measure radiation exposure to their hands during surgery of the finger, hand, and wrist. A total of 81 rings were analyzed. After the clinical study a phantom was used to measure scatter at close range from the mini C-arm. RESULTS: Surgeons' hands were exposed to an average +/- SD of 20 +/- 12.3 mrem/case. For comparison a chest x-ray results in approximately 20 mrem exposure to the patient. Radiation exposure for the group of hand surgeons ranged from 5 to 80 mrem. Surgeons used an average of 51 +/- 36.9 seconds of fluoroscopy time per case. Exposure time for the group ranged from 6 to 170 seconds. The radiation scatter rate decreases precipitously outside the beam or beyond the radius of the intensifier. An average exposure to the hands of 20 mrem/case suggests that surgeons' hands must be entering the beam and getting direct exposure. CONCLUSIONS: Hand surgeons work close to the beam and as a result their hands potentially are exposed to a nontrivial amount of radiation. We recommend that surgeons who use the mini C-arm use precautions to minimize radiation exposure, particularly to their hands.

Fluoroscopy↗
PubMed2006

Usefulness and complications of computed tomography-guided lipiodol marking for fluoroscopy-assisted thoracoscopic resection of small pulmonary nodules: experience with 174 nodules.

OBJECTIVE: Several techniques have been reported for the localization of small pulmonary nodules in thoracoscopic resection. In the present study we examined the usefulness and complications of computed tomography-guided lipiodol marking for thoracoscopic resection in our experience of 174 nodules. METHODS: Computed tomography-guided lipiodol marking was performed on 174 nodules less than 30 mm in size. Of these nodules, 45 showed ground-glass opacity images and 129 showed solid images on computed tomography. The mean size of the nodules was 10 +/- 6 mm (range, 2-30 mm), and their mean depth from the pleural surface was 10 +/- 7 mm (range, 0-30 mm). One to 7 days before thoracoscopy, all of the nodules were marked with 0.4 to 0.5 mL of lipiodol by using computed tomography. The marked nodules were grasped with a ring-shaped forceps during fluoroscopy and resected by means of thoracoscopy. RESULTS: All the nodules could be marked and localized by means of fluoroscopy as a clear spot during thoracoscopic surgery. Complications of the marking were chest pain requiring analgesia in 16 (11%) patients, hemosputum in 11 (6%) patients, pneumothorax in 30 (17%) patients, and hemopneumothorax in 1 (0.6%) patient. Eleven (6%) patients with pneumothorax required drainage, and the patient with hemopneumothorax required an emergency operation. No other complications were observed. CONCLUSION: Lipiodol marking is a useful, safe, and inexpensive procedure for localizing ground-glass opacity lesions, small pulmonary nodules, or both for thoracoscopic resection.

Adult↗
PubMed2005

Comparison of simulator-CT versus simulator fluoroscopy versus surface marking based radiation treatment planning: a prospective study by three-dimensional evaluation.

BACKGROUND AND PURPOSE: Field placement for Radiation Treatment Planning can be done based on the surface markings or simulator fluoroscopy or simulator with CT facilities. A prospective study was carried out to compare these three techniques of radiation treatment planning to quantitatively find out the difference in normal tissue dosages and target volume coverage in the three groups after three-dimensional evaluation. PATIENTS AND METHODS: The CT scans of 30 patients in the treatment position, taken on a Shimadzu SCT-3000 TF scanner at 1cm intervals, were transferred to Theraplan-500 three-dimensional radiation treatment planning computer. The normal tissues and target volumes (GTV and CTV) were outlined on all the CT slices as per (ICRU) Report no. 50. Three types of radiation treatment planning was done sequentially: Plan I-based on the surface markings alone, Plan II-based on simulator-fluoroscopy, and Plan III-based on Simulator-CT. RESULTS: The mean dose to 95% of the clinical target volume (D95) was increased by 4.4 and 6.4% by Plans II and III as compared with Plan I. The mean dose to 3/3rd (D(3/3)) to all the critical organs was decreased by 6.6 and 8.4% by Plans II and III as compared to Plan I. The mean time, in simulator room, for field placement for Plans I-III was 6.2, 14.6 and 44 min, respectively. CONCLUSIONS: Thus for adequate coverage of target volumes and sparing normal tissues, Simulator-CT based radiation treatment planning is the best method of radiation treatment planning though it is more time consuming.

Adult↗
PubMed2005

Fluoroscopy-guided barium marking for localizing small pulmonary lesions before video-assisted thoracic surgery.

PURPOSE: To evaluate the effectiveness of fluoroscopy-guided barium marking for localization of small peripheral pulmonary lesions before video-assisted thoracic surgery (VATS) resection. MATERIAL & METHODS: Twenty-one patients with peripheral pulmonary lesions 15 mm or less in diameter who were scheduled to undergo VATS resection were studied. A catheter was inserted bronchoscopically into the target segment and guided to a presumed lesion. The tip of the catheter was confirmed fluoroscopically to be at the exact spot determined beforehand. A 50% (weight/volume) barium sulfate suspension was instilled into the bronchus through the catheter, and the site of barium marking was ascertained by CT scanning. RESULTS: The average instilled volume of barium was 0.42+/-0.07 ml. On CT scans, barium spots were superimposed on the target lesions in 19 of the 21 patients and were only 6-7 mm from the lesions in the other 2. Barium was well preserved in all patients at the time of VATS resection. A mild cough persisted for about 1 week in one patient, but the other patients had no specific complications. CONCLUSION: Fluoroscopy-guided barium marking is a safe, convenient, and reliable method for localization of small pulmonary lesions before VATS resection.

Adenocarcinoma↗
PubMed2000

Intrathoracic fibrin sealant application using computed tomography fluoroscopy.

Persistent intrathoracic airspace and bronchopleural fistula remain a problem following lung resection or in patients with severe bullous disease experiencing a spontaneous pneumothorax. Although fibrin sealant has been used successfully to manage such air-leaks, precise nonoperative intrathoracic application is difficult. This report describes a novel technique using computed tomography fluoroscopy for catheter-directed FS application through a previously placed thoracostomy tube. Continuous computed tomography-fluoroscopy images allowed real-time catheter manipulation for precise placement of fibrin sealant.

Air↗