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At least 235 records · Page 13Linked to original sources
PubMed1997

Percutaneous nephrostomy: placement under CT and fluoroscopy guidance.

OBJECTIVE: The purpose of this paper is to present our experience with CT- and fluoroscopy-guided percutaneous nephrostomy tube (PNT) placement and to describe the technique of placement with patients in the supine-oblique position. MATERIALS AND METHODS: A CT scanner was coupled with a ceiling-mounted C-arm for fluoroscopy at the CT table, PNT was done with CT localization and fluoroscopic control. We attempted 148 placements in 129 patients, with most patients in the supine or the supine-oblique position. RESULTS: Successful PNT placement was achieved in 144 (97%) of 148 kidneys. In the native kidney group, 101 (81%) of 124 PNTs were placed with the patients in the supine-oblique position. We experienced no major complications, three (2%) minor complications, and two (1%) catheter dislodgments. CONCLUSION: CT-fluoroscopy control allows routine PNT placement with patients in the supine or the supine-oblique position and is associated with the lowest complication rate to our knowledge.

Adolescent↗
PubMedDate not supplied

Accuracy and potential pitfalls of fluoroscopy-guided acetabular cup placement.

Using a total of 30 cadaveric hips, the accuracy of a fluoroscopy-based computer navigation system for cup placement in total hip arthroplasty (THA) was investigated and an error analysis was carried out. The accuracy of placing the acetabular component within a predefined safe zone using computer guidance was compared to the precision that could be achieved with a freehand approach. Accurate control measurements of the implanted cup were obtained using fiducial-based matching to a pre-operative CT scan with respect to the anterior pelvic plane. A significantly higher number of cups were placed in the safe zone with the help of the navigation system. The variability of cup placement could be reduced for cup abduction but not substantially for cup version. An error analysis of inaccurate landmark reconstruction revealed that the registration of the mid-pubic point with fluoroscopy was a potential source of error. Keeping this pitfall in mind, fluoroscopy-based navigation in THA is a useful tool for registration of the pelvic coordinate system, particularly those points that cannot be reached by direct pointer digitization with the patient in the lateral decubitus position.

Acetabulum↗
PubMed2005

Real-time CT fluoroscopy (CTF)-guided vertebroplasty in osteoporotic spine fractures.

The purpose of this study was to evaluate the clinical feasibility, benefits, and limitations of CT fluoroscopy (CTF)-guided percutaneous vertebroplasty (PVP). PVP under the guidance of CTF without additional guidance by conventional C-arm fluoroscopy was performed in a total of 29 vertebral bodies in 21 patients with vertebral compression fractures. While monitoring sectional CTF images, the needle was advanced from the skin to the target vertebra. Contrast media and polymethylmethacrylate (PMMA) were injected into the target vertebra with careful monitoring of their distribution. After the procedure, an evaluation was conducted to determine whether extraosseous leakage of PMMA occurred and whether sufficient filling of PMMA had been achieved. Needle placement into the target vertebra was easily achieved with both the transpedicular and posterolateral approaches. Injection of PMMA and venous leakage of contrast media were carefully monitored in all patients, and early detection of PMMA leaking was achieved in 5 patients. Extraosseous leakage that had not been detected during the procedure was not found upon postoperative evaluation. Pain scales were significantly decreased after the procedure, and no obvious complications occurred following the procedure. CTF-guided PVP without the combined use of C- arm fluoroscopy was feasible and showed definite benefits. We believe that, in spite of some limitations, CTF-guided PVP provides an alternative technique appropriate in certain situations.

Aged↗
PubMed1999

Radiation exposure of Certified Registered Nurse Anesthetists during ureteroscopic procedures using fluoroscopy.

Due to the use of fluoroscopy in the operating room, Certified Registered Nurse Anesthetists (CRNAs) frequently are exposed to the dangers of radiation emitted during surgical procedures using fluoroscopy. The purposes of this research were to determine the level of radiation exposure of the CRNA during fluoroscopic procedures in the operating room and to determine whether these levels are within the limits of maximum permissible dose equivalents published in the Code of Federal Regulations (CFR). This research was conducted in an operating room specifically designated for urological procedures using fluoroscopy. A stationary dosimeter was used to measure radiation exposure. The dosimeter was exchanged monthly for 6 months. Data from this study confirmed that the total radiation exposure was above the limit set by the CFR for whole body radiation exposure, thus exposing the thyroid, which is typically unprotected. The data from this study also supported earlier works that suggested that the radiation to the lens of the eye is of little concern since the exposure rarely exceeds the dose limits set by the CFR.

Certification↗
PubMed2003

Fluoroscopy fade for embolization of vein of Galen malformation.

A fluoroscopy fade technique in the embolization of a vein of Galen malformation in a 10-week-old infant is discussed herein. The availability of the fluoroscopy fade function eliminated the necessity of road mapping during the procedure and permitted minimal usage of contrast material and minimal radiation exposure for the patient. Techniques used during the embolization and the benefits of the fluoroscopy fade feature are also described.

Cerebral Veins↗
PubMed2003

Transesophageal low-energy cardioversion of atrial fibrillation without fluoroscopy outside the electrophysiology laboratory.

BACKGROUND: Low-energy internal cardioversion (LEIC) is a safe and effective procedure for the restoration of sinus rhythm in patients with atrial fibrillation refractory to external cardioversion. However, the procedure needs fluoroscopy and the use of the electrophysiology laboratory, even when the esophageal approach is utilized. The aim of this study was to assess the efficacy, safety and tolerability of a new simplified procedure of esophageal LEIC performed without fluoroscopy, outside the electrophysiology laboratory. METHODS: Thirty consecutive patients (23 males, 7 females) with persistent atrial fibrillation were submitted to LEIC using a step-up protocol (by steps of 50 V, starting from 200 V). Twenty (66%) were resistant to external cardioversion. A large surface area lead (cathode) was positioned within the esophagus, 45 cm from the nasal orifice. A second large surface area lead (anode) was positioned in the right atrium via the right internal jugular vein without fluoroscopic control. Synchronization of delivery of the shock with the QRS was achieved by means of two cutaneous electrodes positioned on the thoracic wall. RESULTS: Sinus rhythm was restored in 28 patients (93%) with a mean delivered energy of 15.2 +/- 7.5 J (range 5-27 J) and a mean impedance of 48.3 +/- 5.6 Ohm. No complication occurred during and after the procedure that was well tolerated under sedation. CONCLUSIONS: This new technique of performing esophageal LEIC is effective and seems to be safe and well tolerated. In this way internal cardioversion can be performed without fluoroscopy, outside the electrophysiology laboratory.

Aged↗
PubMed1992

Radiation exposure during gastroenterologic fluoroscopy: risk assessment for pregnant workers.

With more females in childbearing years participating in fluoroscopic examinations, safety guidelines need to be evaluated. Present recommendations suggest limiting fetal irradiation to less than 500 mrem (0.5 rad) during gestation, and to avoid doses above 100 mrem (0.1 rad) from 8 to 15 wk postconception. The average radiation dose delivered per case was monitored during 10 therapeutic biliary procedures with lithium fluoride dosimeters worn at the endoscopist's collar, over the suprapubic region outside a knee-length 0.5-mm leaded equivalent apron, and inside the apron over the mid-pelvis. A short survey of 15 female technicians and physicians was conducted to gather their opinions about working in fluoroscopy during pregnancy. We found that radiation doses beneath the leaded apron were comparable to environmental exposure. The dose measured at the endoscopist's collar was 0.083 mrem/min. The dose over the pelvis was 0.044 mrem/min. The survey revealed that 13 of those interviewed would not feel safe working near fluoroscopy, and 12 wished to be excluded from fluoroscopy if they became pregnant. We conclude that a high level of anxiety regarding fetal safety exists among females participating in fluoroscopic procedures. In this study, with proper use of standard safety equipment, radiation exposure does not exceed those levels currently recommended to avoid during pregnancy.

Adult↗
PubMed2005

Initial experience of percutaneous vertebroplasty using single-plane C-arm fluoroscopy for guidance.

PURPOSE: The purpose of this study was to evaluate the feasibility and safety of percutaneous vertebroplasty (PVP) using single-plane C-arm fluoroscopy. MATERIALS AND METHODS: Lesions in the present study all comprised compression fractures with intact pedicles. A polymethylmethacrylate (PMMA) mixture was injected by the transpedicular approach under C-arm fluoroscopy using a lateral projection. Before and after PVP, the pain score was determined using visual analog scale methods. RESULTS: Between June 2002 and May 2004, we performed 31 PVPs in 17 patients during 22 treatment sessions. Underlying pathology comprised neoplasm-related compression fracture (n=9) and fractures attributed to osteoporosis (n=8). Mean pain score was 8.0 (range, 4.5-10) immediately before PVP, and 1.9 (range, 0-7) at 24 h after PVP. Mean time needed to perform PVP was 59 min. Mean time to approach a pedicle was 36 min (range, 20 min for 1 pedicle to 110 min for 3 pedicles). No complications requiring surgical intervention or exacerbating conditions beyond pre-treatment levels were noted. CONCLUSION: PVP using single-plane C-arm fluoroscopy for guidance is feasible, safe, and quick.

Adult↗
PubMed2005

[Accuracy of CT-based navigation of pedicle screws implantation in the cervical spine compared with X-ray fluoroscopy technique].

OBJECTIVE: To evaluate the feasibility and accuracy of cervical spine pedicle screw fixation assisted by X-ray fluoroscopy and CT-based navigation system. METHODS: 145 cervical pedicle screws were placed assisted by X-ray fluoroscopy and 159 cervical pedicle screws were placed assisted by CT-based navigation system. Screw positions were evaluated by postoperative CT scans or C-arm X-ray 3 dimensional reconstruction. RESULTS: In the computer- assisted group, 155 (97.5%) screws were found completely within their pedicles compared with 133 (91.7%) correctly placed screws in the X-ray assisted group (P < 0.05). The process of navigation investigated in twenty patients showed that the mean time for registration and surface matching was 3.5 (range from 2 to 8 minutes) minutes and the mean time for screw-marker insertion was 2 (range from 1 to 3.5 minutes) minutes with the mean position deviation 0.31 mm (0.12-0.56 mm) per screw. Only twice C-arm fluoroscopy were performed to verify the accuracy of one screw position intraoperatively. No severe complications like neurovascular lesion occurred in both groups. CONCLUSION: CT-based navigation system can increase the accuracy of cervical pedicle screw implantation significantly.

Adult↗
PubMed2006

[Clinical contrast of cervical pedicle screw fixation assisted by C-arm fluoroscopy or 3D navigation system].

OBJECTIVE: To evaluate the feasibility and accuracy of cervical (C(2)-C(7)) pedicle screw fixation assisted by C-arm fluoroscopy or 3D navigation system (CT-based navigation system or Iso-C 3D navigation system). METHODS: One hundred and forty-five cervical pedicle screws inserted with C-arm fluoroscopy and 187 pedicle screws inserted with 3D navigation system were observed by postoperative CT or Iso-C 3D scan. The process of navigation was investigated. RESULTS: In the 145 screws inserted with C-arm fluoroscopy, 133 screws are accurate (91.7%), and in the 187 screws inserted by 3D navigation system, 183 screws are accurate (97.9%) (chi2 = 6.705, P = 0.010), and the 4 misplaced screws occurred in the early stage of navigation system application. The process of navigation was investigated in twenty-five patients. With CT-based navigation, the mean time for registration and surface matching was 3.5 minutes; with Iso-C 3D navigation, the mean time for images collection and transfer was 6.2 minutes. The mean time for screw-marker insertion was 2 minutes. CONCLUSIONS: 3D navigation system can increase accuracy of cervical pedicle screw fixation obviously.

Adult↗
PubMed1982

A critical assessment of fluoroscopy in peroperative cholangiography.

In a prospective study of 248 patients undergoing peroperative cholangiography fluoroscopy improved the quality of radiographs by ensuring the use of a volume of contrast medium appropriate to each patient's duct capacity and the correct positioning of the ducts away from obscuring objects. Failure of contrast medium to enter the duodenum is usually considered to be an indication for choledochotomy. Although this occurred in 35 patients, the use of fluoroscopy and the injection of an anticholinergic drug without further contrast medium showed the choledochoduodenal junction to be normal, making choledochotomy unnecessary, in 28. The low negative duct exploration rate (3 of 56 patients) and the virtual elimination of false positive peroperative postexploratory cholangiograms (1 of 50 patients) provide further evidence of the value of fluoroscopy.

Biliary Tract Diseases↗
PubMedDate not supplied

[Standardization of the data reported in nasopharyngeal and fluoroscopy study of the velopharyngeal sphincter].

There is a certain global awareness to unify the reports of the findings with the Fiber Optic Endoscopy and The Fluoroscopy in the Velopharyngeal Sphincter. The evaluation must be made by specialists. Nasopharyngoscopy: The required equipment is the nasopharyngoscope with a source of light. A videotape is desirable although not necessary. The report must be descriptive and should arrive at precise conclusions. The following are described: 1) nasal phosae, 2) meatus, 3) the exit orifice of the Eustachian Tube, 4) oropharyx, 5) velopharyngeal sphincter (posterior and lateral pharyngeal walls, and the palatal velum), 6) the closing pattern (form, separate structure, at rest, and in phonation), and 7) larynx. Fluoroscopy: It is useful to evaluate the lateral pharyngeal walls as well as the level at which the velopharyngela sphincter closes. The fluoroscopy is not required in every combination instance. Nevertheless, when it is used, it must be in complement with the nasopharyngoscopy. The videotape is not indispensable. Frontal, lateral, and basal incidences must always be performed.

Endoscopy↗
PubMed2005

Therapeutic endoscopic retrograde cholangiopancreatography without fluoroscopy in four critically ill patients using wire-guided intraductal ultrasound.

Emergent endoscopic retrograde cholangiopancreatography cannot be performed at the bedside in critically ill patients in an intensive care unit because of the requirement for fluoroscopy. Moving such patients to a safe location where fluoroscopy is available can pose practical problems, and can lead to delayed intervention, which may adversely affect the outcome. We report the use of intraductal ultrasound to facilitate therapeutic biliary interventions in four critically ill patients in an intensive care unit. Cannulation was performed endoscopically at the bedside using a sphincterotome and a guide wire. Intraductal ultrasound, rather than fluoroscopy, was then used to confirm the location of the wire within the common bile duct prior to performing endoscopic sphincterotomy or stent placement. This technique was successful in all four patients.

Aged↗
PubMed1990

Validation of left ventricular function parameters acquired with the non-imaging nuclear probe: comparison with tantalum marker cine-fluoroscopy.

We evaluated the accuracy of the non-imaging nuclear probe for measuring various parameters of left ventricular function by comparing these with simultaneous measurements acquired via tantalum marker cine-fluoroscopy. Eight patients with surgically implanted mid-myocardial tantalum markers were studied during cardiac catheterization. High temporal resolution tantalum marker-derived volume/time curves were generated and calibrated to absolute endocardial volumes by comparison with contrast left ventricular angiography. Left ventricular function parameters were acquired at baseline and during atrial pacing, nitroprusside infusion and volume loading. Simultaneous measurements obtained with the nuclear probe and via tantalum marker cine-fluoroscopy were compared. The following correlation coefficients were obtained: ejection fraction, r = 0.49, P less than 0.001; peak ejection rate, r = 0.41, P less than 0.01; mean ejection rate, r = 0.62, P less than 0.001; time to peak ejection, r = 0.73, P less than 0.001; peak filling rate, r = 0.73, P less than 0.001; time to peak filling, r = 0.58, P less than 0.001. Relative changes in end-diastolic volume were accurately tracked by the nuclear probe in six of seven patients (r values 0.77-0.93). These results suggest that measurements of certain left ventricular volume parameters with the nuclear probe may not accurately reflect true volume changes as measured by tantalum marker cine-fluoroscopy. Although, the probe may be useful in tracking relative changes in end-diastolic volume, we would advise caution in using this instrument for studies requiring accurate measurements of ejection and filling parameters.

Cardiac Catheterization↗
PubMed1979

Ultrasound fluoroscopy--what is it, and our approach to your requirements.

A discussion on Ultrasound Fluoroscopy and how it relates to the traditional Real Time Instrumentation. This paper covers the various types of Ultrasound Fluoroscopy Instrumentation, a few of the advantages and disadvantages of each and Unirad Corporation's approach to Ultrasound Fluoroscopy. Also detailed discussions on the technical differences between their approach and the traditional Real Time Instrumentation itemizing electronic beam resolution control in some detail as to its advantages, complexity and comparison to Real Time (Non-focused) and the traditional single element Ultrasound Instruments.

Echocardiography↗
PubMed2001

Dose evaluation and effective dose estimation from CT fluoroscopy-guided lung biopsy.

The development of computerized tomography (CT) has made CT fluoroscopy possible with real-time CT images. However examination are expected to have high medical and occupational exposures. Then, exposures to patients and operating and assisting physicians during the CT fluoroscopy-guided lung biopsy were estimated. And changes in the examination conditions to lower the dose were made. Patient exposure was measured using an anthropomorphic phantom by simulation of clinical examination conditions. The surface dose to the physician was measured during actual clinical examinations. The average effective dose for the patient was 34+/-22mSv. The highest surface dose amounted to 1.9 Gy, although this was in a very narrow field. Patient doses could be reduced by a factor of 2.5-3 by changing examination methods while still retaining diagnostic quality. The highest dose to the operating physician was 10mGy which was recorded on the back of the hand and the average effective dose was estimated as 5.99&mgr;Sv per 1-minute examination. Doses were reduced by about a factor of 50 by lowering the tube voltage from 120kV to 80 kV and using a supplementary tool. The doses for assisting physicians were not significant. The exposure for physicians and patients was much affected by lowering the tube voltage used for fluoroscopy. Using a supplementary tool was effective for reducing the dose for physicians.

Journal Article↗
PubMed1981

Arterial imaging with computerized fluoroscopy.

Computerized fluoroscopy (CF) allows visualization of any segment of the arterial vascular system with intravenous injection of small volumes of standard iodinated contrast media. Because it avoids the risk of arterial puncture and the need for hospitalization, this technique is safer and more economical than standard arteriography. Because of these advantages, CF is likely to expand the role of arteriography in the clinical management of vascular disease. Computerized arteriographic imaging requires an intravenous power injection of 40 to 60 cc of iodinated contrast media. Immediately after injection, six to ten fluoroscopic images (1/15 sec duration) are obtained at 1.5-sec intervals. The first image serves as a mask from which subsequent images are serially subtracted by means of a digital video image processor. The sequence of different images is contrast enhanced and stored on a video disk. Video images are converted to hard copy arteriography with a standard multiformat camera. Technical failures (<5%) may result from patient motion, inadequate peripheral venous access, or extravasation of contrast media. Nearly 600 computerized intravenous arteriograms have been performed in 240 patients with peripheral vascular disease. Qualitative com-parisons with standard arteriograms suggest a close correlation between these two imaging techniques. Computerized fluoroscopy allows the identification of atheromatous plaque ulceration, stenoses, occlusions, and aneurysms. This method has been used to visualize the aortic arch and its branches, the cervical and intracranial vessels, the abdominal aorta, and arteries of the extremities. Computerized fluoroscopy has great potential as a method for safe, simple diagnostic screening and assessment of the postoperative patient.

Journal Article↗
PubMed1999

MR fluoroscopy using projection reconstruction multi-gradient-echo (prMGE) MRI.

A projection reconstruction multi-gradient-echo (prMGE) technique is presented. The introduced technique is an extension of a standard projection reconstruction steady-state gradient-echo technique allowing for the acquisition of several gradient echoes after each excitation of the spin system. Each echo train is used for acquiring data of a certain angular segment of k-space. By use of echo trains consisting of up to four echoes, the overall acquisition time for a 128(2) image can be reduced to 150 ms without sacrificing image quality. Results are presented for cardiac fluoroscopy, for the visualization of swallowing, and for the visualization of joint motion. For all investigated applications promising results have been obtained. Especially in parts of the body where motion on an even shorter time scale than the acquisition process or significant in-plane or through-plane flow are within the field of view, the introduced technique appears to be a promising technique for MR fluoroscopy. Magn Reson Med 42:324-334, 1999.

Deglutition↗