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PubMed1995

Intracardiac echocardiography without fluoroscopy: potential of a balloon-tipped, flow-directed ultrasound catheter.

Intracardiac echocardiography is a technique that uses catheter-based ultrasound transducers placed within the heart to image cardiac structures. One disadvantage to this technique is that it requires fluoroscopy for catheter placement. This study was performed to evaluate a prototype balloon-tipped, flow-directed catheter for use during intracardiac echocardiography in seven dogs. With the balloon deflated, the catheter could not be successfully advanced without fluoroscopy. Even with fluoroscopic imaging, catheter advancement was often difficult. With the balloon inflated, it could easily be passed into the pulmonary artery without fluoroscopy in 12 of 14 attempts. Images of the cardiac chambers, valves, and pulmonary artery could be obtained. In conclusion, use of a balloon-tipped, flow-directed catheter for intracardiac echocardiography and pulmonary artery imaging can be performed without the use of fluoroscopy. With continued refinements, such as enhancement of the visual field, intracardiac echocardiography could possibly be performed at the bedside to assess cardiac function or assist with interventional procedures.

Animal Population Groups↗
PubMed1995

Comparison of the diagnostic value of cinefluoroscopy and simple fluoroscopy in the detection of calcification in coronary arteries.

AIM: Comparison of the diagnostic value of cinefluoroscopy and simple fluoroscopy in the detection of calcification in coronary arteries. PATIENTS AND METHODS: Data were prospectively obtained from 143 patients in whom simple fluoroscopy as well as cinecoronary arteriography were performed. Excluded were patients with a previous myocardial infarction, a previous abnormal cinecoronary arteriogram and patients with unstable angina. With the coronary arteriogram as the gold standard, the likelihood ratios (LR) of simple fluoroscopy were determined, mismatches with cinefluoroscopy were analysed and Kappa, as a measure for inter-test agreement, was calculated. RESULTS: The LRs with 95% confidence intervals for a positive and negative result were 5.3 (2.6-11.0) and 0.43 (0.28-0.69), respectively. There was a mismatch in 12 (8.3%) patients. Kappa with a 95% confidence interval was 0.90 (0.73-1.0). CONCLUSIONS: Both test modalities are almost identical and conclusions with respect of the diagnostic value of cinefluoroscopy also holds for simple fluoroscopy.

Calcinosis↗
PubMed1995

Bedside fluoroscopy to screen for simple extremity trauma in the ED.

Portable fluoroscopy units are commonly used by orthopedic surgeons to assist in fracture reduction and immobilization. The purpose of this study was to determine the diagnostic accuracy of bedside fluoroscopy performed by emergency department (ED) physicians to screen for simple extremity trauma. Eligible adult patients presenting to the ED with isolated injuries to distal extremities were evaluated prospectively over a 6-month study period. ED physicians independently performed fluoroscopy at the bedside, obtained real-time images (frontal, lateral, and oblique), and documented their initial interpretations. Patients then underwent routine diagnostic radiographs of the same areas. Fluoroscopic findings (real-time and photographs) were compared with the radiologists' final report. Ninety-two patients with 108 extremity injuries were enrolled in the study. Fractures were diagnosed fluoroscopically in 26 cases, for a sensitivity of 0.70. Of the 71 standard radiographs without a fracture, the fluoroscopic diagnosis was accurate in 66, for a specificity of 0.93. The overall diagnostic accuracy was 0.85, with a 95% confidence interval of .67 to 1.00. There were 11 false-negative fluoroscopic reports, involving the radius (3), distal tibia (3), metacarpals (2), fifth metatarsal (1), phalanx (1), and cuboid (1). These results suggest that bedside fluoroscopy lacks sufficient sensitivity to screen for simple extremity fractures in the ED.

Adult↗
PubMed1979

Bladder function in children with meningomyelocele: comparison of cine-fluoroscopy and urodynamics.

We have assessed 60 children on an outpatient basis with cine-fluoroscopy combined with urodynamics. Bladder and rectal pressure together with sphincter electromyography were measured during bladder filling under fluoroscopy, which was followed by measurement of rectal pressure and sphincter electromyography during voiding under fluoroscopy. Comparison of the x-ray studies and urodynamics showed that the cystogram alone was not a reliable indicator of ray studies and urodynamics showed that the cystogram along was not a reliable indicator of detrusor function. The sphincter electromyogram during voiding must be interpreted in the face of intra-abdominal pressure changes owing to straining or Credé's maneuver. Residual urine estimations and the appearance of the bladder outflow on fluoroscopy were better parameters of outflow obstruction than sphincter electromyography.

Adolescent↗
PubMed2001

Non-vascular intervention with real-time CT fluoroscopy.

The emerging technology of CT fluoroscopy (CTF) represents the first opportunity for real-time CT guidance in non-vascular intervention. As with any new technology, its efficacy requires validation before widespread application can be advocated. A review of our initial experience is presented with particular attention to room, procedure and fluoroscopy time savings, complication rates and dosimetry. Computed tomography fluoroscopy is useful for pulmonary, pelvic, retroperitoneal and other deep organ lesions that are not easily accessible by other modalities. Computed tomography fluoroscopy decreases procedure time by at least a factor of 2 compared with conventional CT (C-CT) guidance, resulting in improved throughput in a busy interventional CT department. Accurate targeting of small lesions, previously considered inaccessible, can also be achieved with CTF. Exposure to the physician's hands can be reduced to a level that is acceptable to the International Commission on Radiological Protection guidelines.

Biopsy↗
PubMed2002

Pediatric radiofrequency catheter ablation registry success, fluoroscopy time, and complication rate for supraventricular tachycardia: comparison of early and recent eras.

INTRODUCTION: To assess changes of success rate, fluoroscopy time, and complication rate for six supraventricular tachycardia pathways/ mechanisms, data from the Pediatric Radiofrequency Catheter Ablation Registry were grouped into two eras (1991-1995; 1996-1999). METHODS AND RESULTS: Data from the early era and the late era were compared using the Chi-square test for the outcomes of success rate and complication rate and using the Student's t-test for the outcome of mean fluoroscopy time. In the Registry as a whole, ablation failure rates fell from 9.6% in the early era to 4.8% in the recent era, a reduction of 50% overall. Improved success rates were found for posterior septal, right free-wall, and left free-wall pathways and for AV nodal reentry, whereas anterior septal pathways and atrial ectopic-focus tachycardia did not show improvement. Mean fluoroscopy time overall decreased 21% from 50.9 +/- 39.9 minutes to 40.1 +/- 35.1 minutes. Individually, the improvement in fluoroscopy time was found for all but the atrial ectopic-focus tachycardia mechanism. The complication rate decreased from 4.2% to 3.0%, with significant decreases for left free-wall and posterior septal pathways. CONCLUSION: Patient selection strategies to optimize radiofrequency ablation outcomes in children, which have been based on the previously published Registry data, should be reconsidered in light of these new, updated data. The lack of uniform improvement provides the impetus for further research and development of new approaches and technologic advances so that further improvement can be achieved.

Adolescent↗
PubMed2005

[Fluoroscopy time -- an overestimated factor for patient radiation exposure in invasive cardiology].

PURPOSE: To analyze the effects of an optimized fluoroscopy time on patient radiation exposure in the course of coronary angiography (CA) and percutaneous coronary interventions (PTCA), in comparison to those with consistent collimation to the region of interest (ROI). Furthermore, to analyze efforts concerning reduction of radiographic frames as well as concerning adequate instead of best possible image quality. MATERIAL AND METHODS: For 3,115 elective CAs and 1,713 PTCA performed by one interventionist since 1997, we documented the radiographic dose-area products (DAP (R)) and fluoroscopic dose-area products (DAP (F)), the number of radiographic frames and the fluoroscopy times during selected 2-month intervals. Under conditions of constant image intensifier entrance dose, levels of DAP (R)/frame and DAP (F)/s represent valid parameters for consistent collimation. RESULTS: In 1997, the mean baseline values of DAP for elective CA and PTCA amounted to 37.1 and 31.6 Gy x cm (2), respectively. A reduction of mean fluoroscopy times from 264 to 126 seconds for CA and from 630 to 449 seconds for PCI, both resulted in an overall DAP-reduction of merely 20 %. Optimization of mean radiographic frames from 543 to 98 for CA and from 245 to 142 for PTCA enabled reductions of 53 and 13 %, respectively. By restriction to adequate instead of best-possible image quality for coronary angiography in clinical routine, we achieved an optimized radiographic DAP/frame of 30.3 to 13.3 mGy x cm (2), which enabled a 45 % reduction of overall DAP. Most efficient however was a consistent collimation to the ROI, which resulted in a remarkable radiation reduction by 46 % for CA and by 65 % for PTCA. CONCLUSIONS: Radiation-reducing educational efforts in the clinical routine of invasive cardiology should -- against widely held opinion -- focus less exclusively toward a reduction of fluoroscopy time but more efficiently toward consistent collimation to the region of interest, reduction of radiographic frames and restriction to an adequate instead of best-possible image quality.

Angioplasty, Balloon, Coronary↗
PubMed1997

[The intracavitary administration of contrast medium in the aftercare of complicated thoracic empyema with long-term drainage: x-ray fluoroscopy compared to computed tomography].

PURPOSE: To define the value of conventional radiography compared with CT in the follow-up of complicated, long-term tube drained pleural empyema after intracavitary application of contrast medium. METHODS: 28 patients with complicated pleural empyema (stage III) and long-term tube drainage were submitted to fluoroscopy of the pleural cavity and a CT of the thorax after contrast medium had been instilled into the pleural space. Both examinations were judged by the following criteria: number and morphology of pleural cavities, quality of drainage and accompanying thoracic disease. RESULTS: 49 pleural cavities were diagnosed. Judgement of drainage corresponded in 79% of cases and differed in 21% with proof of further not drained cavities only on CT. 4 bronchopleural fistulas were diagnosed by fluoroscopy, of which only 2 were evident on CT. Accompanying thoracic disease was reliably detected by CT only. CONCLUSIONS: Diagnosis of bronchopleural fistulas and judgement of the pleural drainage is best possible using fluoroscopy after application of contrast medium into the pleural space. CT is most accurate to detect further cavities that have not been drained, to look for concomitant thoracic disease, and to judge the morphology of the pleural cavity. Conventional radiography of the pleural space is effective and recommended to be used as a first line investigation for the follow-up of stage III empyemas. Patients in poor general condition (fever, elevated blood markers indicating inflammation) should be examined by both fluoroscopy and CT.

Adolescent↗
PubMed2001

Placement of esophageal self-expanding metallic stents without fluoroscopy.

BACKGROUND: Fluoroscopy is routinely used to guide the placement of self-expanding metallic stents for the palliative treatment of patients with esophageal malignancy. This is a description of a novel method of stent placement without fluoroscopy. METHODS: This technique relies on a clear endoscopic view of the proximal radiopaque marker on the stent. This was achieved by the application of an external white marker at this level. A gastroscope was passed, allowing guidewire deployment and measurement of stricture length. The endoscope was reinserted and placed alongside the guidewire giving direct visualization of the proximal margin of the stricture. The stent delivery device was positioned, keeping the white mark visible proximal to the stricture, and the stent was deployed. RESULTS: Thirty consecutive patients with inoperable esophageal malignancy underwent endoscopic placement of self-expanding metal stents. Deployment in satisfactory position without fluoroscopy was successful in 23 of 30 (77%); there were no complications. CONCLUSIONS: The majority of esophageal stents can be accurately positioned without fluoroscopy.

Adenocarcinoma↗
PubMed2005

The ACIST power injection system reduces the amount of contrast media delivered to the patient, as well as fluoroscopy time, during diagnostic and interventional cardiac procedures.

The ACIST injection system is an automatic power injection device that allows for online control of injection rate and volume of contrast. Limited data is available whether this technology allows reducing use of contrast and fluoroscopy time. Accordingly, we compared the use of this system to manual injection among 450 consecutive patients who underwent diagnostic coronary angiography and/or angioplasty who were randomly assigned to either manual contrast injection (control; n=198) or to the ACIST system (study group; n=252). The amount of contrast, fluoroscopy and total procedural times were recorded for each patient. In the diagnostic group, the mean total amount of contrast (including wasted) was reduced by 63% when the ACIST was used compared to control (100+/-42 ml versus 163+/-56 ml; P<0.001, respectively). When only the net amount of contrast delivered to the patient was considered, the differences were smaller (20%, P=0.004). During angioplasty, the amount of contrast was also lower in the ACIST group (206+/-65 versus 230+/-69, P=0.008), whereas no difference were noted in net amount of contrast. Fluoroscopy time was significantly shorter in the ACIST group compared to control both during diagnostic catheterization (4.7+/-3.5 min versus 6.3+/-5.5 min, respectively; P=0.014), and angioplasty (16.7+/-9.1 min versus 19.6+/-12.4 min, respectively; P=0.05). Routine utilization of the ACIST system during diagnostic and interventional procedure significantly reduced the total amount of contrast media used and fluoroscopy time.

Aged↗
PubMed2002

Fluoroscopy-guided intraarticular corticosteroid injection into the sacroiliac joints in patients with ankylosing spondylitis.

PURPOSE: Our goal was to prospectively study the therapeutic efficacy of CT-marking and fluoroscopy-guided intraarticular corticosteroid instillation of inflamed sacroiliac joints in patients with ankylosing spondylitis. MATERIAL AND METHODS: A total of 22 fluoroscopy-guided intraarticular corticosteroid injections in the sacroiliac joints were performed in 17 patients with ankylosing spondylitis and severe low back pain. Needle puncture point, angle of intervention and distance of sacroiliac joint from the skin were determined by sacroiliac joint axial CT examination in prone position. 14 mg of betamethasone were instilled in each joint under fluoroscopy. RESULTS: Twenty of 22 joints (90.9%) reported good improvement during a month after corticosteroid injection of the sacroiliac joint. The remaining 2 joints reported fair improvement. CONCLUSION: CT-marking and fluoroscopy-guided intraarticular corticosteroid instillation in the sacroiliac joints may be regarded as an effective therapy. This technique was useful, rapid and safe.

Adult↗
PubMed2005

Reduction of fluoroscopy exposure and procedure duration during ablation of atrial fibrillation using a novel anatomical navigation system.

AIMS: Catheter ablation of atrial fibrillation (AF) is centred on pulmonary vein (PV) ablation with or without additional atrial substrate modification. These procedures may be prolonged with significant fluoroscopy exposure. This study evaluates a new non-fluoroscopic navigation system during ablation of AF. METHODS AND RESULTS: Seventy-two patients undergoing catheter ablation of symptomatic drug refractory AF were prospectively randomized to ablation with (n=35; study group) or without (n=37; control group) non-fluoroscopic navigation. PV isolation was performed in all patients. In patients with persistent or inducible sustained AF after PV isolation linear ablation was performed by joining the superior PVs. PV isolation was achieved in all patients; fluoroscopy (15.4+/-3.4 vs. 21.3+/-6.4 min; P<0.001) and procedural (52+/-12 vs. 61+/-17 min; P=0.02) durations were significantly reduced in the study group. Linear block was achieved in 37 of the 39 patients; with a significant reduction in fluoroscopy (5.6+/-2.2 vs. 9.9+/-4.8 min; P=0.003) and procedural (14.7+/-5.5 vs. 26.6+/-16.9 min; P=0.007) durations in the study group. After a follow-up of 6.9+/-2.9 months (range 3-10), 26 (74%) patients in the non-fluoroscopic navigation group and 29 (78%) patients in the control group were arrhythmia-free after the first procedure. CONCLUSION: This prospectively randomized study demonstrates significant reduction of fluoroscopy exposure and procedural duration using supplementary non-fluoroscopic imaging system for AF ablation.

Adult↗
PubMed2001

The quality assurance and constancy checking of fluoroscopy and fluorography systems.

X ray procedures which involve fluoroscopy often give significant radiation doses to patients. A valuable radiation protection procedure is the adoption of a quality assurance programme which will ensure the continual production of optimal quality images with the minimum necessary dose to the patient. Various publications exist which provide information on quality assurance (QA) and constancy checking of fluoroscopy and fluorography systems. These publications were reviewed and tests recommended for QA and constancy checking of fluoroscopy and fluorography systems are presented. It was found that not much information exists on QA and constancy checking for digital subtraction angiography and digital fluorography systems. More research is required in this field. Information on protocols used by various countries of the European Community for QA and constancy checking of fluoroscopy and fluorography systems was gathered. From this information it is apparent that there is a need for harmonisation within Europe.

European Union↗
PubMed1997

Interventional magnetic resonance. Initial clinical experience with a 1.5-tesla magnetic resonance system combined with c-arm fluoroscopy.

RATIONALE AND OBJECTIVES: The authors evaluate the feasibility of performing magnetic resonance (MR) procedures on a 1.5-tesla (T) system combined with conventional c-arm fluoroscopy. METHODS: A 1.5-T MR imaging system was combined with a conventional c-arm fluoroscopy unit in one room. The two systems were connected via a floating table top. Twenty-six interventional procedures (biopsies, MR-portography, percutaneous alcohol injection, laser ablation, fluid aspiration, and breast marking) were performed in 22 patients under MR, fluoroscopic control, or both. For MR guidance, fast gradient echo sequences were used, initiated from a panel at the front of the magnet. Images were displayed on an liquid crystal display screen positioned on the magnet. RESULTS: All MR-guided procedures were performed successfully without complications. The addition of c-arm fluoroscopy was useful for bone interventions and MR-portography. All diagnostic biopsies yielded sufficient amounts of tissue for histologic diagnosis. In breast lesions, the target identified on dynamic MR imaging was marked correctly in each case. In interstitial laser thermotherapy the laser effect could be visualized, and in percutaneous ethanol injection the distribution of the alcohol could be seen. Both imaging systems worked without image distortions and high-quality MR images were obtained. CONCLUSIONS: The combination of a 1.5-T MR imager with a c-arm fluoroscopy system seems to be a promising technical solution for performing interventional MR procedures.

Adult↗
PubMed2006

Cervical spine clearance in unconscious traumatic brain injury patients: dynamic flexion-extension fluoroscopy versus computed tomography with three-dimensional reconstruction.

BACKGROUND: An optimal protocol for clearing the cervical spine in unconscious patients with traumatic brain injury remains controversial. Protocols include plain radiographs and computed tomography (CT), and ligamentous injury may be identified with flexion-extension radiographs. We questioned whether cervical CT with three-dimensional (3D) reconstructions may obviate the need for flexion-extension radiology in the detection of occult ligamentous injury. METHODS: Between July 1999 and November 2001, 276 unconscious traumatic brain injured patients admitted to The Alfred Hospital received cervical spine plain radiographs, CT with 3D reconstructions, and dynamic flexion-extension X-ray studies with fluoroscopy as part of a routine protocol. These patients were identified from a prospective intensive care unit database and all radiology reports were reviewed. RESULTS: Dynamic flexion-extension X-ray studies with fluoroscopy identified no new fractures or instability; there were no instances of true-positive results. Dynamic flexion-extension was true-negative in 260 of 276 (94%) patients, falsely positive in six patients (2.2%) and falsely negative in one (0.4%) patient. In nine patients, dynamic flexion-extension was inadequate. CONCLUSION: Dynamic flexion-extension X-ray studies with fluoroscopy delayed cervical spine clearance and were almost always reported as normal. In a cervical spine clearance protocol for unconscious traumatic brain injury patients, dynamic flexion-extension X-ray studies with fluoroscopy did not identify any patients with cervical fracture or instability not already identified by plain radiographs and fine-cut CT (C0 to T2) with 3D reconstructions.

Algorithms↗
PubMed2003

Heart-surface reconstruction and ECG electrodes localization using fluoroscopy, epipolar geometry and stereovision: application to noninvasive imaging of cardiac electrical activity.

To date there is no imaging modality for cardiac arrhythmias which remain the leading cause of sudden death in the United States (> 300000/yr.). Electrocardiographic imaging (ECGI), a noninvasive modality that images cardiac arrhythmias from body surface potentials, requires the geometrical relationship between the heart surface and the positions of body surface ECG electrodes. A photographic method was validated in a mannequin and used to determine the three-dimensional coordinates of body surface ECG electrodes to within 1 mm of their actual positions. Since fluoroscopy is available in the cardiac electrophysiology (EP) laboratory where diagnosis and treatment of cardiac arrhythmias is conducted, a fluoroscopic method to determine the heart surface geometry was developed based on projective geometry, epipolar geometry, point reconstruction, b-spline interpolation and visualization. Fluoroscopy-reconstructed hearts in a phantom and a human subject were validated using high-resolution computed tomography (CT) imaging. The mean absolute distance error for the fluoroscopy-reconstructed heart relative to the CT heart was 4 mm (phantom) and 10 mm (human). In the human, ECGI images of normal cardiac electrical activity on the fluoroscopy-reconstructed heart showed close correlation with those obtained on the CT heart. Results demonstrate the feasibility of this approach for clinical noninvasive imaging of cardiac arrhythmias in the interventional EP laboratory.

Algorithms↗
PubMed1995

Bedside fluoroscopy for the detection of foreign bodies.

OBJECTIVE: To determine the sensitivity and specificity of portable fluoroscopy for foreign-body detection using an ex-vivo experimental model. METHODS: A prospective, randomized masked investigation was performed to characterize foreign-body detection in cubes of beef. Three emergency physicians (EPs) independently used a portable fluoroscope to determine the presence or absence of various foreign bodies in ten cubes of beef (approximately 6 cm on each side). Six different groups of foreign bodies were examined: glass, wood, graphite (pencil lead), metal (needle), plastic, and gravel. An independent observer placed the six objects randomly into each set of ten beef cubes. One hundred observations were made by each physician using sets of ten beef cubes at a time. RESULTS: Fluoroscopy detected 117 of 180 foreign bodies (sensitivity 65%; 95% CI 58-72%), including all cubes of beef embedded with gravel, metal, and glass. Graphite was detected 27 of 30 times (sensitivity 90%; 95% CI 74-98%). None of the plastic or wooden foreign bodies was identified despite magnification techniques and real-time imaging (sensitivity 0%; 95% CI0-12%, each). Of the 120 cubes of meat with no foreign body, two false-positives were recorded (specificity 98%; 95% CI 94-100%). The overall positive predictive value and negative predictive value of fluoroscopy were 98% and 65%, with 95% CIs of 94-100% and 58-72%, respectively. Interobserver agreement between the three EPs was considered excellent (kappa = 0.75). CONCLUSION: Bedside fluoroscopy lacks sufficient sensitivity to rule out many foreign bodies in the ED. Its use should be limited to suspected gravel, glass, pencil lead, and metallic objects, which are known to be radiopaque.

Emergency Medicine↗
PubMed2002

A training program in portable fluoroscopy for the detection of glass in soft tissues.

OBJECTIVES: The role of emergency department (ED) bedside fluoroscopy is incompletely defined. One potential application is the evaluation of glass foreign bodies (GFBs). We studied the effect of a training intervention on the ability of emergency physicians to detect GFBs in an established chicken leg model. We also studied performance one week after training. METHODS: Assessment of this teaching intervention involved nine emergency medicine residents with minimal prior hands-on fluoroscopy experience. Zero, one, or two clear glass shards no larger than 1.0 mm in any dimension were inserted into fresh chicken legs. Each subject scanned 12 to 15 legs without being given any feedback to determine baseline accuracy. Next, 27 to 30 more legs were immediately scanned with feedback given after each response. Subjects scanned 15 more legs one week later without feedback as follow-up. Data were analyzed using mixed-model analysis of variance. RESULTS: At baseline, overall sensitivity and specificity were 0.40 and 0.61, respectively. At follow-up, sensitivity and specificity were 0.93 and 0.91, respectively. Subjects were significantly more accurate during training and follow-up than at baseline. This level of proficiency reached during training was maintained and continued to improve one week later. CONCLUSIONS: Emergency medicine residents previously inexperienced in fluoroscopy may, through a brief training intervention, acquire the skill to accurately detect small pieces of glass in a chicken leg model, and maintain proficiency one week later. Further studies of emergency department fluoroscopy in GFB management in humans are warranted.

Animals↗