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At least 289 records · Page 16Linked to original sources
PubMed2001

Fluoroscopy-assisted thoracoscopic surgery after computed tomography-guided bronchoscopic barium marking.

BACKGROUND: Small lesions of the peripheral lung have been detected more frequently with the recent prevalence of computed tomography (CT). Identification of these lesions is indispensable for wedge resection performed by video-assisted thoracic surgery. Previous reports of marking techniques showed some failure and complications. We have developed a new marking technique and herein describe the efficacy of this technique: fluoroscopy-assisted thoracoscopic surgery after computed tomography-guided bronchoscopic barium marking. METHODS: Twenty patients underwent this procedure for 21 small peripheral pulmonary lesions approximately 10 mm in size. RESULTS: All the lesions were successfully marked and identified during fluoroscopy-assisted thoracoscopy. They were resected with sufficient margins. There were no complications related to this procedure. The pathologic examination of these 21 lesions revealed primary lung cancer in 14, atypical adenomatous hyperplasia in four, a metastatic tumor in one, and a benign tumor in two. CONCLUSIONS: This procedure is both a reliable and minimally invasive technique in thoracoscopic wedge resection for small peripheral pulmonary lesions.

Adult↗
PubMed1981

Implantation of permanent transvenous atrial J lead using lateral view fluoroscopy.

Fifty consecutive, tined, atrial J leads were implanted for atrial and atrioventricular sequential pacing using lateral view fluoroscopy for atrial lead manipulation and positioning. The technique is described in detail. It is concluded that lateral view fluoroscopy allows a more expeditious and reliable positioning in the right atrial appendage.

Fluoroscopy↗
PubMed2001

Esophageal stent placement without fluoroscopy.

BACKGROUND: Access to fluoroscopic equipment is limited in some regions where esophageal cancer is common. This report describes a simple method for placement of expandable esophageal stents without fluoroscopy. METHODS: Patients with dysphagia due to unresectable esophageal cancer underwent esophageal stent placement under endoscopic control alone. A colored mark on the stent delivery catheter was used to properly position the undeployed stent with respect to the proximal end of the tumor. RESULTS: Stent placement was attempted in 70 patients and was successful in every case. There were no immediate complications of stent placement. Mean dysphagia score decreased from 3.3 before stent placement to 0.5 at follow-up. There was a trend toward lower dysphagia scores in patients who received coated stents. CONCLUSION: Expandable esophageal stents can be accurately and safely placed under direct endoscopic control, without fluoroscopy.

Adult↗
PubMed2003

Fluoroscopy-guided laparoscopy in the management of intraabdominal foreign body.

Appendicitis or perforation as a result of intraluminal foreign body is uncommon. The method of diagnosis and proper approach for an elective appendectomy in an otherwise silent intraluminal foreign body is under dispute. A laparoscopic exploration under intraoperative fluoroscopy guidance was performed in a mentally retarded 9-year-old boy with asymptomatic foreign bodies in the right lower abdominal quadrant. The authors recommend laparoscopic appendectomy, assisted by intraoperative fluoroscopy for patients with pointed foreign bodies in the appendix.

Appendectomy↗
PubMed1997

Operative fluoroscopy in hand and upper limb surgery. One hundred cases.

We reviewed the use of a low radiation portable fluoroscopy unit in 100 patients. The most common indication was closed reduction of distal radial fractures. Fracture and joint stability were assessed on the real-time monitor and stored on videotape. Static images were stored on thermographic paper. Fluoroscopically guided joint injections and localization of implants, foreign bodies and bone tumours were performed. Fluoroscopy is a useful adjunct to arthroscopic assisted fracture reduction and other arthroscopic procedures such as distal ulnar resection. These new generation units produce superior resolution images, are easy to manoeuvre and do not require a radiographer.

Bone Neoplasms↗
PubMed1998

The use of fluoroscopy to guide needle placement in interstitial gynecological brachytherapy.

PURPOSE: Interstitial brachytherapy is generally performed for gynecological malignancies with extensive parametrial involvement, by inserting the needles through a transperineal template. Often, the implanted needles are not parallel, and the multiple sources can be difficult to identify on localization radiographs, especially if obtained with a portable X-ray unit. We have used fluoroscopy to guide the needles for interstitial brachytherapy to treat various gynecological malignancies. Because the resultant needles are parallel, dosimetry can be performed based on the template hole positions used, rather than identifying individual sources. This report focuses on the technique; the outcome of patients implanted with this technique will be reported separately. METHODS: Seventy-one patients were implanted transperineally with 192iridium using a Syed template under fluoroscopic guidance, from September 1989 to May 1995, for bulky parametrial disease, narrow vagina, extensive vaginal involvement, recurrent disease after previous course of pelvic radiation therapy, or in cases in which the patient had previously undergone hysterectomy. 137Cesium was added in a central tandem in cases with a cervical os. Thirty patients were treated for primary cervical or vaginal carcinoma; 41 patients were treated for recurrent disease from endometrial or cervical cancers. The brachytherapy dose (prescribed to the periphery of the implant) was 40 to 55 Gy when used alone (15 patients) and 22-40 Gy when used as a boost to 34.2 to 59.4 Gy of pelvic external-beam radiotherapy (56 patients). The patients were followed for 6 to 63 months. RESULTS: In all cases, some of the needles had to be repositioned to improve the alignment. Hence, the use of fluoroscopy aided in achieving parallel placement of the needles in all implants as seen on anterior-posterior radiographs. Because the 192iridium sources were ordered beforehand based on the preplan, and the dosimetry was based on idealized geometry of the template hole positions, all patients were loaded on the same day of implant. CONCLUSION: Fluoroscopically guided perineal interstitial brachytherapy is a feasible technique for use in various gynecological malignancies. The use of fluoroscopic guidance helped to achieve parallel needle placement in all of our implants, but it required repositioning of some of the needles in all cases. The parallel positioning allowed the use of preplanned dosimetry, minimizing the delay in loading of the patients. The outcome of the patients treated using this technique is currently undergoing analysis and will be reported separately.

Brachytherapy↗
PubMed2005

Atrioventricular node ablation and permanent ventricular pacemaker implantation without fluoroscopy: use of an electroanatomic navigation system.

Non-fluoroscopy AV ablation and pacemaker implantation. Fluoroscopic guidance is the standard tool used for transvenous pacemaker implantations and for electrophysiological and ablation procedures. It implies X-ray exposure, occasionally with high dose of radiation for the patient and operator. We describe the case of a 47-year-old man with uncontrollable permanent atrial fibrillation to whom ablation of the AV conduction and a permanent ventricular pacemaker implantation were successfully performed under the guidance of an electroanatomic navigation EnSite NavX system and with no use of fluoroscopy. This case illustrates the stand-alone use of one of the new non-fluoroscopic navigation systems for a complete procedure such as AV ablation and pacemaker implantation.

Atrial Fibrillation↗
PubMed2003

Digital fluoroscopy as a valuable adjunct to open vascular operations.

The increasing availability of and vascular surgeons' familiarity with digital cine-fluoroscopy in the operating room has been facilitated by the advent and growing popularity of endovascular aortoiliac aneurysm repair and other endovascular techniques that are being incorporated into vascular surgical practice. Digital cine-fluoroscopy can also be used as a valuable adjunct to standard open vascular procedures in several ways including: performance of completion angiography, fluoroscopically-assisted thromboembolectomy, intraoperative planning angiography, fluoroscopically-guided pressure gradient measurements, achieving vascular control of proximal arteries, intraoperative thrombolysis of compromised outflow tracts, and angioplasty and stenting of lesions detected intraoperatively. These techniques can improve the outcome of standard vascular procedures by permitting the identification of inflow, outflow, conduit, and anastomotic defects intraoperatively and guiding their repair. Additionally, in many cases they can reduce the amount of exposure required, reduce intraoperative blood loss, and minimize trauma to vessels during thrombectomy. Fluoroscopic guidance can facilitate and improve these and other aspects of standard open vascular procedures. Conversely, the ability to perform open interventions can facilitate the performance of many endovascular interventions. It is becoming increasingly important to be facile with both open and E fluoroscopically guided techniques in order to fully treat the spectrum of vascular disease in an optimum fashion.

Angiography↗
PubMed2002

Frameless stereotaxy as an alternative to fluoroscopy for transsphenoidal surgery: use of the InstaTrak-3000 and a novel headset.

Our aim was to evaluate the applicability of an electromagnetic-based frameless stereotactic system for use in transsphenoidal surgery. The system utilizes a novel headset that acts as a replaceable fiducial frame as well as a fixation point for the system's transmitter. It can replace the fluoroscope as a guide to navigation in the sphenoid sinus and sella. The system was used in a consecutive series of 11 patients undergoing transsphenoidal surgery. It was used in conjunction with intraoperative fluoroscopy. We found the Instatrak-3000 to correlate well with lateral fluoroscopic images, and provide additional information in the axial and coronal planes. The InstaTrak-3000 frameless stereotactic system is accurate and obviates the need for intraoperative fluoroscopy during transsphenoidal surgery. Compared to other frameless systems, it avoids the use of fiducial skin markers and head fixation. In common with other frameless stereotactic systems, it provides additional information important for safely approaching the sella and avoids intraoperative radiation exposure for the patient and operating room staff.

Adenoma↗
PubMed2000

Access for percutaneous transhepatic cholangioscopy in patients with nondilated bile ducts using nasobiliary catheter cholangiography and oblique fluoroscopy.

BACKGROUND: Percutaneous transhepatic biliary drainage is required for percutaneous transhepatic cholangioscopy. However, puncture of nondilated bile ducts under ultrasonographic guidance is difficult. METHODS: In 10 patients with no ultrasonographic evidence of intrahepatic bile duct dilatation, percutaneous transhepatic biliary drainage was performed under fluoroscopic guidance using cholangiography obtained via a nasobiliary drainage catheter. Direct puncture was performed by means of a left ventral approach using oblique C-arm fluoroscopy. RESULTS: Bile duct puncture was successful in all patients. There were no procedure-related complications. Subsequent cholangioscopy was successful in all patients. CONCLUSIONS: Direct puncture using nasobiliary drainage cholangiography and oblique fluoroscopy is a useful method when cholangioscopy is necessary in patients with nondilated bile ducts.

Adult↗
PubMed2003

Fluoroscopy-assisted dual-catheter thromboembolectomy: a new technique useful in patients with embolization to arteries of disproportionate diameters.

Distal embolization is a complication of aortoiliac aneurysm repair. Fluoroscopy-assisted catheter thromboembolectomy is useful in removing popliteal and tibial emboli from the femoral approach. Concomitant presence of aortoiliac and popliteal aneurysms, a known association, may present a difficult challenge to embolus extraction. Currently available embolectomy catheters large enough for thrombus extraction from a popliteal aneurysm are too large for safe tibial artery cannulation, and tibial balloon catheters cannot be enlarged sufficiently to transfer the thrombus through the aneurysmal popliteal segment. We treated a patient who embolized to his popliteal aneurysm and distal tibial circulation following aortoiliac aneurysm repair. A fluoroscopy-assisted dual-catheter technique was used to extract the thrombus through the femoral approach, eliminating the need for direct popliteal or tibial exploration. This technique uses two balloon catheters of graduated size, maneuvered concurrently under fluoroscopic guidance into the tibial and popliteal circulation. The smaller tibial catheter is inflated, and thrombus is withdrawn into the popliteal segment. The larger popliteal balloon catheter is then inflated distal to the smaller catheter, and both catheters are withdrawn simultaneously to deliver the clot through the femoral arteriotomy. This technique can be useful for successful balloon catheter extraction of thrombus via remote access, in an arterial system with variable diameter, eliminating the need for direct popliteal or tibial exploration.

Aged↗
PubMed1997

Digital fluoroscopy before and after laser uvulopalatopharyngoplasty in obstructive sleep apnea. Importance of pharyngeal collapsibility and hyoid bone position.

PURPOSE: To study the changes in pharyngeal behavior after laser uvulopalatopharyhgoplasty (LUPPP). MATERIAL AND METHODS: The dynamic changes in the upper airway size were evaluated with digital fluoroscopy in 24 patients with obstructive sleep apnea (OSA) before and after LUPPP and in 16 normal controls, while they were awake and breathing normally. Cephalometric measurements were also made. The patients were classified into the categories of good and poor responders by means of a static-charge-sensitive bed. RESULTS: Following LUPPP, collapsibility at the velopharyngeal level was within the normal range m 15 of 17 good responders, but only in 2 of 7 poor responders (p = 0.0086). The minimum airway size at the same level showed a similar trend. In 3 of 7 poor responders the hyoid bone was positioned more caudally than in the good responders (p = 0.017). CONCLUSION: Digital fluoroscopy provides information on the change in upper airway behavior after LUPPP.

Adult↗
PubMed1995

Evaluation of image quality in fluoroscopy by measurements and Monte Carlo calculations.

We have studied image quality in fluoroscopy, as related to the detectability of low-contrast iodine or acrylic (PMMA) details added to a homogeneous 20 cm thick PMMA phantom, by experimental measurements of the signal-to-noise ratio (SNR) and by Monte Carlo calculation. The agreement between the measured and calculated SNR at equal absorbed dose in the phantom showed that the imaging performance of x-ray image intensifier (XRII) based fluoroscopic systems is well understood and can be mainly accounted for by x-ray attenuation in the phantom and the detail, and by the interaction statistics of primary and secondary (scattered) x-ray quanta in the input phosphor of the XRII. The electronic noise sources in the video chain had only a small effect on the detectability of the details studied here. The optimal x-ray tube potential was 50-60 kV for detecting the low-contrast iodine detail in the phantom, and 70-100 kV for detecting the thin PMMA detail. For the task of detecting the iodine detail the use of a fibre-interspaced antiscatter grid improved the dose-to-information conversion efficiency of the imaging system by a factor of 2.2 as compared to imaging without the grid, and additional filtering of the x-ray beam by 0.25 mm Cu increased the efficiency by a factor of 1.6. Monte Carlo results were further used to estimate the potential of increasing the dose-to-information conversion efficiency by imaging system design changes. For the detection task of a static, low-contrast, low-spatial-frequency iodine contrast material detail embedded in a 20 cm thick soft-tissue phantom, the greatest contributions for further improvement could be achieved by improved antiscatter devices, x-ray spectrum modification, and by decreasing the absorption in the material layers in front of the CsI phosphor of the XRII. Contrary to this, no significant efficiency increase could be obtained by increasing the CsI phosphor coating thickness from the present value of 180 mg cm-2, or by changes in the video chain characteristics. The maximum potential of efficiency improvement is a factor of 6.3 when compared to the reference fluoroscopy system operated at 60 kV with 2.7 mm Al primary beam filtration, and a factor of 3.9 when compared to the reference system at 50 kV with the primary beam filtration added by 0.25 mm Cu.

Fluoroscopy↗
PubMed1998

Computer-aided radiation therapy simulation: image intensifier spatial distortion correction for large field of view digital fluoroscopy.

An accurate method of correcting spatial distortion in digital fluoroscopy images has been developed for generating fluoroscopy-based large field of view images for computer-aided radiation therapy simulation. This method is applicable to arbitrary gantry rotations and arbitrary shifts of the image intensifier relative to the central axis of the x-ray beam. It is therefore suitable for conventional radiation therapy simulation techniques that involve the arbitrary positioning of the image intensifier by the operator. Spatial distortion is modelled as two image intensifier orientation-dependent components, the first resulting from the projection of the x-ray image onto the curved surface of the image intensifier front end, and the second produced by the image intensifier electron optics, interactions with external magnetic fields and the video system. A geometrical model approximates the first component. The second component is modelled by a third-order polynomial transformation. A weighted mean approach is employed to achieve accurate distortion correction when the image intensifier is oriented differently from the calibration orientations. Mean and maximum residual errors (measured in the plane of the isocentre) of 0.4 mm and 1.0 mm respectively have been achieved with just 48 calibration orientations in four dimensions (gantry rotation and lateral, longitudinal and vertical shifts of the image intensifier).

Calibration↗
PubMed1999

A search for improved technique factors in paediatric fluoroscopy.

A Monte Carlo computational model of a fluoroscopic imaging chain was used for deriving optimal technique factors for paediatric fluoroscopy. The optimal technique was defined as the one that minimizes the absorbed dose (or dose rate) in the patient with a constraint of constant image quality. Image quality was assessed for the task of detecting a detail in the image of a patient-simulating phantom, and was expressed in terms of the ideal observer's signal-to-noise ratio (SNR) for static images and in terms of the accumulating rate of the square of SNR for dynamic imaging. The entrance air kerma (or air kerma rate) and the mean absorbed dose (or dose rate) in the phantom quantified radiation detriment. The calculations were made for homogeneous phantoms simulating newborn, 3-, 10- and 15-year-old patients, barium and iodine contrast material details, several x-ray spectra, and for imaging with or without an antiscatter grid. The image receptor was modelled as a CsI x-ray image intensifier (XRII). For the task of detecting low- or moderate-contrast iodine details, the optimal spectrum can be obtained by using an x-ray tube potential near 50 kV and filtering the x-ray beam heavily. The optimal tube potential is near 60 kV for low- or moderate-contrast barium details, and 80-100 kV for high-contrast details. The low-potential spectra above require a high tube load, but this should be acceptable in paediatric fluoroscopy. A reasonable choice of filtration is the use of an additional 0.25 mm Cu, or a suitable K-edge filter. No increase in the optimal tube potential was found as phantom thickness increased. With the constraint of constant low-contrast detail detectability, the mean absorbed doses obtained with the above spectra are approximately 50% lower than those obtained with the reference conditions of 70 kV and 2.7 mm Al filter. For the smallest patient and x-ray field size, not using a grid was slightly more dose-efficient than using a grid, but when the patient size and field size were increased a fibre interspaced grid resulted in lower doses than imaging without a grid. For a 15-year-old patient the mean absorbed doses were up to 40% lower with this grid than without the grid.

Adolescent↗
PubMed2006

Fluoroscopy-assisted retroperitoneal laparoscopic renal surgery in children.

PURPOSE: To investigate the use of C-arm fluoroscopy for locating small dysplastic renal lesions during retroperitoneal laparoscopic nephrectomy in children. PATIENTS AND METHODS: From March 2003 to March 2005, two boys and four girls with a mean age of 5 years underwent retroperitoneal laparoscopic nephrectomy under C-arm fluoroscopic guidance. The indications for laparoscopic renal surgery were ectopic ureter with dysplastic kidney (N = 3), hypertensive nephropathy (N = 1), and dysplastic kidney secondary to reflux nephropathy (N = 2). RESULTS: All operations were completed with no necessity for conversion to open surgery. Small dysplastic kidneys were easily located using C-arm fluoroscopy, and retroperitoneal laparoscopic nephrectomy was then performed. One patient required open contralateral reimplantation after laparoscopic nephrectomy because of high-grade vesicoureteral reflux. The mean operative time was 139 minutes (range 71-210 minutes). Blood loss was minimal, and no transfusion was required. There were no intraoperative or postoperative complications other than a peritoneal injury in one patient, which caused no subsequent major problem. The mean postoperative hospital stay was 3.8 days, and all children returned to normal activity within 3 to 6 days. CONCLUSIONS: This is the first report to our knowledge of retroperitoneal laparoscopic renal surgery under C-arm fluoroscopic guidance. This approach allowed quick and easy location of small ectopic kidneys prior to retroperitoneal laparoscopic nephrectomy and was found to be very useful for the treatment of small dysplastic renal lesions in children.

Child↗
PubMed1998

The role of lateral cephalometric radiography and fluoroscopy in assessing mandibular advancement in sleep-related disorders.

Mandibular advancement splints are successful in managing obstructive sleep apnoea (OSA) in selected subjects. For these to be effective, some improvement in the dimensions of the oropharyngeal airway must occur. Twenty subjects with proven obstructive sleep apnoea were examined using lateral cephalometric radiography and a fluoroscopic technique. Cephalograms were analysed, and assessed for both skeletal and soft tissue abnormalities known to be present in OSA subjects. On the basis of these, a prediction was made as to whether the subject's oropharyngeal airway would increase during mandibular protrusion. From the fluoroscopic sequences, the narrowest antero-posterior dimensions of the post-palatal and post-lingual airways were recorded as the mandible moved from the intercuspal position into maximal protrusion. The changes in airway size were noted and these were compared with the predictions made from the static films. In nine subjects, fluoroscopy indicated that the airway opened well during mandibular protrusion, seven did not improve and in four the changes were minimal. Post-palatally the mean airway increase was 2.6 mm, whilst behind the tongue a mean improvement of 3.1 mm was seen. In all but two instances, the cephalometric prediction agreed exactly with the outcome demonstrated by fluoroscopy. All subjects whose airways clearly increased were correctly identified by the cephalogram alone. Cephalometric features associated with a good airway response to protrusion were a reduced lower facial height, low maxillomandibular planes angle and a high hyoid position, accompanied by a normal anteroposterior relationship of the jaws, relatively normal mandibular body length and soft palate area. The more abnormal the skeletal and soft tissue dimensions, the poorer the prognosis. Thus, whilst a single radiograph could indicate whether a positive mandibular response to protrusion could be expected, where doubt existed, a fluoroscopic analysis could provide a useful adjunct to diagnosis.

Adult↗
PubMed2006

Quantification of motion unsharpness in digital fluoroscopy.

The objectives of this work were first to develop a convenient method to quantify persistence in digital fluoroscopy systems, then to quantify the effect of variable temporal averaging on the detection of moving low-contrast test details within digital fluoroscopic and pulsed fluoroscopic images. The results were analysed to clarify the relationship between the optimum persistence required to see the lowest contrast for circular test details for a range of diameters and their speed of movement. The optimum persistence values obtained are compared with the limited data available on speeds of movement of patient organs during fluoroscopy. It is tentatively concluded that for imaging the abdomen, the optimum imaging system persistence time constant is approximately 0.15 s. For the much greater speeds associated with cardiac motion, no additional frame averaging is necessary, i.e. just the persistence provided by the observer's visual system appears to be optimal for small objects.

Fluoroscopy↗