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At least 397 records · Page 22Linked to original sources
PubMed1989

Transbronchial biopsy without fluoroscopy: a five year experience in outpatients.

Transbronchial biopsy is the technique of choice for obtaining tissue for histological diagnosis in many pulmonary disorders. The procedure has usually been carried out as an inpatient procedure with the use of fluoroscopy, though this policy has recently been questioned. This report concerns a five year experience of 174 transbronchial biopsies performed without fluoroscopy as an outpatient procedure in patients with interstitial lung disease or a suspicion of sarcoidosis. Chest radiography was carried out only if the patient developed symptoms. No major complications were encountered and the overall complication rate was low. Pneumothorax occurred in six patients (3.4%), only one of whom required intercostal intubation, and bleeding of more than 30 ml occurred in two patients. Histological diagnosis was obtained in 154 patients (88%). In the experience of this group transbronchial biopsy has been safe when carried out as an outpatient procedure without fluoroscopic guidance.

Ambulatory Care↗
PubMed2003

Is fluoroscopy necessary for sacroiliac joint injections?

The use of sacroiliac joint injection has been a steadily increasing for therapeutic and diagnostic purposes in the United States. Because of the conceivably easy accessibility of sacroiliac joint and reported low incidence of morbidity, the sacroiliac joint injection is felt to be a procedure that maybe performed easily in the office based setting. While this procedure may be common, the sacroiliac joint injection is not performed accurately without the aide of imaging. Further complicating the issue of sacroiliac joint injections is the lack of specific and reliable diagnostic testing. Clinical evaluation and imaging studies are often unreliable and practitioners often mistakenly assume that pain over the posterior superior iliac spine is pathognomonic for sacral joint pain. In addition, referral patterns are unreliable and bedside testing is often non-diagnostic. Sixty patients undergoing sacroiliac joint injections were studied. Sacroiliac joint injections were placed blindly then examined under fluoroscopy for accurate needle placement. The needle was placed by a single this experienced spinal injectionist. Results of blind needle placement revealed that only 5 of 60 patients were felt to have needle placement approximating a therapeutic point of contact with the sacroiliac joint. Furthermore, the posterior superior iliac spine, was found to be a poor indicator of sacroiliac joint anatomic access. The results of this study show that accurate placement of sacroiliac joint injections is successful without fluoroscopy in only 12% of the patients, even in experienced hands.

Journal Article↗
PubMed1999

Fluoroscopy as an imaging means for computer-assisted surgical navigation.

OBJECTIVE: Intraoperative fluoroscopy is a valuable tool for visualizing underlying bone and surgical tool positions in orthopedic procedures. Disadvantages of this technology include the need for continued radiation exposure for visual control, and cumbersome means of alignment. The purpose of this article was to highlight a new concept for a computer-assisted freehand navigation system that uses single intraoperatively acquired fluoroscopic images as a basis for real-time navigation of surgical tools. MATERIALS AND METHODS: Optoelectronic markers are placed on surgical tools, a patient reference, and the fluoroscope to track their position in space. Projection properties of the fluoroscope are acquired through an initial precalibration procedure using a tracked radiopaque phantom grid. Corrections are applied to compensate for both the fluoroscope's image intensifier distortions and the mechanical bending of the C-arm frame. This enables real-time simulation of surgical tool positions simultaneously in several single-shot fluoroscopic images. In addition, through optoelectronically tracked digitization of a target viewpoint, the fluoroscope can be numerically aligned at precise angles relative to the patient without any X-ray exposure. RESULTS: This article shows the feasibility of this technology through its use in cadaver trials to perform the difficult task of distal locking of femoral nails.

Bone Nails↗
PubMed1998

Fluoroscopy and selective angiography of left ventricular assist system inflow cannula as a method of detecting cannula entrapment.

Left ventricular assist systems have become an important tool as a bridge to cardiac transplantation. Malfunction of these devices often leads to clinical and hemodynamic deterioration. One potential complication is the obstruction of the inflow cannula secondary to remodeling of the left ventricular cavity. We report two cases where fluoroscopy and selective angiography were used to visualize the orientation and obstruction of the inflow cannula when echocardiographic findings were indeterminant.

Adult↗
PubMed1999

Interactive three-point localization of double-oblique sections using MR fluoroscopy.

Magnetic resonance imaging allows significant freedom in selecting the orientation and position of a tomographic section. However, it can nonetheless be challenging to determine quickly and efficiently the correct parameters required to image a targeted anatomic structure that may lie at an oblique angle in the imaging volume. We describe a three-point tool in which a) the user interactively selects three points from an anatomic structure of interest during live MR fluoroscopy; b) adjustments to pulse sequence are calculated to image the tomographic section defined by the three points; and c) the section is then immediately imaged fluoroscopically. The tool allows quick localization of, for example, longitudinal images of specific arterial structures.

Algorithms↗
PubMed2002

Evaluating the etiology of mechanical valve obstruction: use of clinical parameters, fluoroscopy, and echocardiography.

Prosthetic valve obstruction is a life-threatening complication most commonly caused by thrombus, pannus, or both. We report a St. Jude tricuspid valve obstruction, initially treated with thrombolytic therapy, found to be caused by pannus on pathologic examination. Clinical evaluation and diagnostic evaluation with fluoroscopy and echocardiography in distinguishing pannus from thrombus are reviewed.

Coronary Thrombosis↗
PubMed2001

Clinical results of percutaneous pelvic surgery. Computer assisted surgery using ultrasound compared to standard fluoroscopy.

This study presents early results of clinical experience with the application of Computer Assisted Surgery (CAS) to percutaneous iliosacral screwing, with comparison to a historical series of patients treated using percutaneous fluoroscopy. Four patients were instrumented using a CAS system, with 10 screws being inserted. Thirty patients were treated by percutaneous fluoroscopic screwing, with 51 screws being inserted. The follow-up assessment included the following criteria; operative time, parameters of radiation exposure, neurological examination, screw placement evaluation on CT-scan, antalgic drug consumption, pain, Majeed grading, and loosening of implants. In the CAS group, the average radiation time was 0.35 min per patient and 0.14 min per screw. No trajectories outside the bone and no postoperative neurological deficits were found. In the fluoroscopic group, the average radiation time was 1.03 min per patient and 0.6 min per screw. Twelve screws had outside-bone trajectories, and iatrogenic neurological deficits were found in seven patients. The average operative time was 50 min in the CAS group and 35 min in the fluoroscopic group. The present CAS technique shows better placement of iliosacral screws, with no outside-bone trajectories and lower radiation exposure.

Adult↗
PubMed2007

A simple method to accurately position Port-A-Cath without the aid of intraoperative fluoroscopy or other localizing devices.

BACKGROUND: To evaluate the efficacy and acceptability of the Port-A-Cath (PAC) insertion method with (conventional group as II) and without (modified group as I) the aid of intraoperative fluoroscopy or other localizing devices. METHODS: A total of 158 women with various kinds of gynecological cancers warranting PAC insertion (n = 86 in group I and n = 72 in group II, respectively) were evaluated. Data for analyses included patient age, main disease, dislocation site, surgical time, complications, and catheter outcome. RESULTS: There was no statistical difference between the two groups in terms of age, main disease, complications, and the experiencing of patent catheters. However, appropriate positioning (100% in group I, and 82% in group II) in the superior vena cava (SVC) showed statistical differences between the two groups (P = 0.001). In addition, the surgical time in group I was statistically shorter than that in group II (P < 0.001). CONCLUSIONS: The modified method for inserting the PAC offered the following benefits: including avoiding X-ray exposure for both the operator and the patient, defining the appropriate position in the SVC, and less surgical time.

Anesthesia, Local↗
PubMed2001

Embedded MR fluoroscopy: high temporal resolution real-time imaging during high spatial resolution 3D MRA acquisition.

A method termed "embedded fluoroscopy" for simultaneously acquiring a real-time sequence of 2D images during acquisition of a 3D image is presented. The 2D images are formed by periodically sampling the central phase encodes of the slab-select direction during the 3D acquisition. The tradeoffs in spatial and temporal resolution are quantified by two parameters: the "redundancy" (R), the fraction of the 3D acquisition sampled more than once; and the "effective temporal resolution" (T), the time between temporal updates of the central views. The method is applied to contrast-enhanced MR angiography (CE-MRA). The contrast bolus dynamics are portrayed in real time in the 2D image sequence while a high-resolution 3D image is being acquired. The capability of the 2D acquisition to measure contrast enhancement with only a 5% degradation of the spatial resolution of the 3D CE-MR angiogram is shown theoretically. The method is tested clinically in 15 CE-MRA patient studies of the carotid and renal arteries.

Feasibility Studies↗
PubMed1995

Magnetic resonance fluoroscopy using spirals with variable sampling densities.

The imaging of dynamic processes in the body is of considerable interest in interventional examinations as well as kinematic studies, and spiral imaging is a fast magnetic resonance imaging technique ideally suited for such fluoroscopic applications. In this manuscript, magnetic resonance fluoroscopy pulse sequences in which interleaved spirals are used to continuously acquire data and reconstruct one movie frame for each repetition time interval are implemented. For many applications, not all of k-space needs to be updated each frame, and nonuniform k-space sampling can be used to exploit this rapid imaging strategy by allowing variable update rates for different spatial frequencies. Using the appropriate reconstruction algorithm, the temporal updating rate for each spatial frequency is effectively proportional to the corresponding k-space sampling density. Results from a motion phantom as well as in in vivo gadolinium diethylenetriaminopentaacetic acid (Gd-DTPA) bolus tracking studies in a rat model demonstrate the high temporal resolution achievable using these techniques as well as the tradeoffs available with nonuniform sampling densities. This paper focuses on the acquisition of real-time dynamic information, and all images presented are reconstructed retrospectively. The issues of real-time data reconstruction and display are not addressed.

Animals↗
PubMed2005

Comparison of X-ray fluoroscopy and interventional magnetic resonance imaging for the assessment of coronary artery stenoses in swine.

The accuracy of a two-step interventional MRI protocol to quantify coronary artery disease was compared to the clinical gold standard, X-ray angiography. Studies were conducted in nine swine with a surgically induced stenosis in the proximal left circumflex coronary artery. The two-step protocol consisted of catheter-directed magnetic resonance angiography (MRA), which was first used to localize the stenosis, followed by MRI cross-sectional images to quantify the degree of stenosis without the use of contrast agent. Line signal intensity profiles were drawn across the vessel diameter at the stenosis site and proximal to the stenosis for each data set to measure percentage stenosis for each animal. Catheter-directed MRA successfully detected eight of nine stenoses. Cross-sectional MRI accurately quantified each stenosis, with strong agreement to the measurements made using X-ray fluoroscopy (intraclass correlation coefficient = 0.955; P < 0.05). This study demonstrates that in the future interventional MRI may be an alternative to X-ray angiography for the detection and quantification of coronary artery disease.

Angiography↗
PubMed2005

Model of a vascular C-arm for 3D augmented fluoroscopy in interventional radiology.

This paper deals with the modeling of a vascular C-arm to generate 3D augmented fluoroscopic images in an interventional radiology context. A methodology based on the use of a multi-image calibration is proposed to assess the physical behavior of the C-arm. From the knowledge of the main characteristics of the C-arm, realistic models of the acquisition geometry are proposed. Their accuracy was evaluated and experiments showed that the C-arm geometry can be predicted with a mean 2D reprojection error of 0.5 mm. The interest of 3D augmented fluoroscopy is also assessed on a clinical case.

Computer-Aided Design↗
PubMedDate not supplied

A new coaxial needle system, hepatic artery targeting wire, and biplane fluoroscopy to increase safety and efficacy of TIPS.

To improve safety and efficacy of the transjugular intrahepatic portosystemic shunt (TIPS) procedure, we introduced a new, thin-needle (21-gauge long PTC needle) puncture technique using biplane fluoroscopy and targeting of a guidewire tip in the right hepatic artery. After puncture of the right portal vein, a 0.016-inch guidewire was inserted into the portal vein, followed by a 4 Fr dilator. The 4 Fr dilator allowed introduction of a 0.035-inch working guidewire. We successfully performed TIPS in seven patients with postnecrotic cirrhosis using this technique and encountered no technical difficulties or complications.

Fluoroscopy↗
PubMed1978

[X-ray dose reduction in examination of infant's hip with image-intensifier-fluoroscopy-system (author's transl)].

An image intensifier--70mm camera--fluoroscopy system combined with a conventional X-ray tube is used for routine examination of the infant's hip. The high quality of 85% of these 70mm exposures makes immediate diagnostic interpretation possible. An even higher percentage can be achieved by most exact positioning of the patients. Apart from the radiation protection of the gonades, the X-ray skin dose of the primary beam is reduced by 90-95% compared with full size radiography using film screen combinations. This exposure technique can certainly be used not only for the examination of the infant's hip.

Fluoroscopy↗
PubMed1982

Declining volume of gastrointestinal fluoroscopies: a survey of 18 hospitals.

A survey of the volume of gastrointestinal fluoroscopies at 18 hospitals suggests a decline in the number of these examinations performed over the past 5 years. Data were acquired on 4 types of examinations: upper gastrointestinal series, small bowel studies, barium enemas (all types), and oral cholecystograms. Modest decreases of 8.4%, 10.3%, and 2.0% were noted in the numbers of upper gastrointestinal examinations, small bowel examinations, and barium enemas, respectively. A considerable decline of 45.9% was found in performance of oral cholecystograms. An overall decline of 14.4% was noted for all 4 examinations.

Barium Sulfate↗
PubMed1999

Real-time imaging and triggering of 3D contrast-enhanced MR angiograms using MR fluoroscopy.

Although a variety of timing techniques and data acquisition strategies have been used for three-dimensional contrast-enhanced MR angiography, many are still limited by inadequate overall reliability, limited spatial resolution, or complexity. A technique is presented in this work in which contrast arrival is detected in the targeted vasculature in real time using MR fluoroscopy. Upon detection the operator triggers a 3D MR angiographic acquisition which uses an elliptical centric view order. It is shown that the view order intrinsically provides a high degree of venous suppression which in turn allows acquisition times of 30 s or longer, permitting high spatial resolution. The reliability of fluoroscopic triggering in bolus detection is shown to be over 90%. The technique provides high quality contrast-enhanced MR angiograms for many vascular regions.

Carotid Arteries↗
PubMed1999

Computed tomography-fluoroscopy guided injection of cyanoacrylate to mark a pulmonary nodule for thoracoscopic resection.

BACKGROUND: There have been several reports regarding aids to localize small and/or deeply situated peripheral pulmonary lesions thoracoscopically. However, we have found that they were not always reliable and have attempted to use a cyanoacrylate adhesive as an alternative. METHOD: We injected 0.1-0.2 ml of Histoacryl (n-butyl-2-cyanoacrylate) blue through a 22 gauge long needle to the lung parenchyma immediately beneath the pleural surface that was nearest to the target nodule. Following local anesthesia of the thoracic wall, we inserted the needle tip to the desired position under CT-fluoroscopic guidance. After retracting the syringe piston to confirm that no blood was aspirated, we injected the adhesive and immediately removed the needle. RESULTS: The adhesive polymerized immediately after its injection into the lung parenchyma to form a hard nodule. There was no complication except mild pneumothorax and slight pain at the puncture site. The adhesive nodule measured 1.0-1.5 cm in diameter and was hard enough to be easily located thoracoscopically in all the 8 patients/9 nodules studied. The nodule was also recognizable by its blue color visible under the pleura. CONCLUSION: CT-fluoroscopy guided injection of Histoacryl blue provided a reliable marker for the localization of pulmonary nodules, especially in those patients with severe anthracosis in the pulmonary parenchyma.

Adult↗
PubMed2000

A new approach to computer-aided spine surgery: fluoroscopy-based surgical navigation.

A new computer-based navigation system for spinal surgery has been designed. This was achieved by combining intraoperative fluoroscopy-based imaging using conventional C-arm technology with free-hand surgical navigation principles. Modules were developed to automate digital X-ray image registration. This is in contrast to existing computed tomography- (CT) based spinal navigation systems, which require a vertebra-based registration procedure. Cross-referencing of the image intensifier with the surgical object allows the real-time image-interactive navigation of surgical tools based on one single registered X-ray image, with no further image updates. Furthermore, the system allows the acquisition and real-time use of multiple registered images, which provides an advanced multi-directional control (pseudo 3D) during surgical action. Stereotactic instruments and graphical user interfaces for image-interactive transpedicular screw insertion have been developed. A detailed validation of the system was performed in the laboratory setting and throughout an early clinical trial including eight patients in two spine centers. Based on the resulting data, the new technique promises improved accuracy and safety in open and percutaneous spinal surgery.

Bone Screws↗