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PubMedDate not supplied

A comparative study of CT fluoroscopy combined with fluoroscopy versus fluoroscopy alone for percutaneous transhepatic biliary drainage.

PURPOSE: We compared CT fluoroscopy (CTF) for the initial puncture of bile ducts with conventional fluoroscopic guidance in patients with malignant jaundice in whom percutaneous transhepatic biliary drainage (PTBD) was planned. METHODS: Forty consecutive patients were randomized to two study groups: group A underwent PTBD under CTF and fluoroscopic guidance, group B underwent PTBD under fluoroscopic guidance alone. CTF-guided PTBD was performed using a combination of a helical CT scanner of the latest generation and a mobile C-arm; conventional PTBD was performed under fluoroscopic guidance in the angiographic unit. End points of the study were the success (a puncture that enabled safe placement of a guidewire in a suitable bile duct) and the complication rate (hemobilia, bile fistula, biliary peritonitis), the number of punctures required, the time needed for successful puncture of a suitable bile duct, and the patient's radiation exposure. RESULTS: CTF-guided puncture of peripheral bile ducts suitable for PTBD was successful at the first attempt in 16 cases, under conventional fluoroscopic guidance, in only two cases. We found a significantly different number of punctures (1.2 in group A vs 2.9 in group B), a significantly shorter time for puncture in group A (mean 39 sec), but also a significantly higher skin exposure dosage in group A (mean 49.5 mSv surface dosage). There was no significant difference regarding the total procedure time. Only one complication occurred in group B (portobiliary fistula). CONCLUSION: CTF-guided initial puncture of bile ducts allowed a significantly reduced number of punctures and puncture times compared with puncture under conventional fluoroscopic guidance for placement of percutaneous transhepatic biliary drainage catheters.

Adult↗

PubMed2007

Patient skin dose in cardiac interventional procedures: conventional fluoroscopy versus pulsed fluoroscopy.

OBJECTIVES: To investigate whether pulsed fluoroscopy reduces a patient's exposure compared with the exposure owing to conventional (continuous) fluoroscopy, we simulated the skin radiation doses of patients at cardiac catheterization facilities with various X-ray systems used in fluoroscopically guided intervention procedures. BACKGROUND: Although many reports have noted that "pulsed fluoroscopy" provides important further reductions in radiation exposure, it has been determined that when comparing dose rates between different vendor systems, "pulsed fluoroscopy" does not reduce patients' exposure as compared with "conventional fluoroscopy". METHODS: We examined 13 X-ray systems; 10 used pulsed fluoroscopy and three used conventional fluoroscopy. The entrance surface doses with fluoroscopy were compared for the 13 X-ray systems by using acrylic plates (20-cm thick) and a skin dose monitor. The X-ray conditions used in the measurements were those normally used in the facilities performing percutaneous coronary intervention. RESULTS: The average surface dose for systems from three different vendors producing conventional fluoroscopy systems was 23.93+/-2.77 mGy/min vs. an average surface dose of 22.52+/-4.50 mGy/min from five vendors of pulsed fluoroscopy systems (25, 30, and 50 pulses/sec) (P=0.646). The average entrance surface dose was significantly (P<0.0001) higher with conventional fluoroscopy and pulsed fluoroscopy at 25, 30, and 50 pulses/sec (23.05+/-3.78 mGy/min) than with pulsed fluoroscopy at 15 pulses/sec (13.86+/-3.22 mGy/min). CONCLUSIONS: Pulsed fluoroscopy did not in itself reduce radiation exposure. In general, the use of pulsed fluoroscopy at a pulse rate lower than 25 pulses/sec should reduce the skin dose in fluoroscopically guided intervention procedures. Nevertheless, some X-ray systems are not designed to reduce the dose rate as the number of pulses per second is decreased. Physicians should be aware of the entrance surface dose of the X-ray system that they use for cardiac IVR.

Cardiac Catheterization↗

PubMed2003

CT arthrography of the glenohumeral joint: CT fluoroscopy versus conventional CT and fluoroscopy--comparison of image-guidance techniques.

PURPOSE: To compare examination time with radiologist time and to measure radiation dose of computed tomographic (CT) fluoroscopy, conventional CT, and conventional fluoroscopy as guiding modalities for shoulder CT arthrography. MATERIALS AND METHODS: Glenohumeral injection of contrast material for CT arthrography was performed in 64 consecutive patients (mean age, 32 years; age range, 16-74 years) and was guided with CT fluoroscopy (n = 28), conventional CT (n = 14), or conventional fluoroscopy (n = 22). Room times (arthrography, room change, CT, and total examination times) and radiologist times (time the radiologist spent in the fluoroscopy or CT room) were measured. One-way analysis of variance and Bonferroni-Dunn posthoc tests were performed for comparison of mean times. Mean effective radiation dose was calculated for each method with examination data, phantom measurements, and standard software. RESULTS: Mean total examination time was 28.0 minutes for CT fluoroscopy, 28.6 minutes for conventional CT, and 29.4 minutes for conventional fluoroscopy; mean radiologist time was 9.9 minutes, 10.5 minutes, and 9.0 minutes, respectively. These differences were not statistically significant. Mean effective radiation dose was 0.0015 mSv for conventional fluoroscopy (mean, nine sections), 0.22 mSv for CT fluoroscopy (120 kV; 50 mA; mean, 15 sections), and 0.96 mSv for conventional CT (140 kV; 240 mA; mean, six sections). Effective radiation dose can be reduced to 0.18 mSv for conventional CT by changing imaging parameters to 120 kV and 100 mA. Mean effective radiation dose of the diagnostic CT arthrographic examination (140 kV; 240 mA; mean, 25 sections) was 2.4 mSv. CONCLUSION: CT fluoroscopy and conventional CT are valuable alternative modalities for glenohumeral CT arthrography, as examination and radiologist times are not significantly different. CT guidance requires a greater radiation dose than does conventional fluoroscopy, but with adequate parameters CT guidance constitutes approximately 8% of the radiation dose.

Adolescent↗

PubMed2000

Comparison of C-arm CT fluoroscopy and conventional fluoroscopy for percutaneous biliary drainage procedures.

PURPOSE: To conduct a prospective randomized evaluation of C-arm computed tomography (CT) fluoroscopy for external biliary drainage procedures in comparison with conventional fluoroscopic guidance to reduce the number of transhepatic punctures as a primary endpoint. MATERIALS AND METHODS: In 18 patients with biliary obstructions, 20 external percutaneous biliary drainage procedures were prospectively performed with use of either C-arm CT fluoroscopy or conventional fluoroscopy alone. The number of hepatic punctures, procedure time, and fluoroscopy time, were analyzed separately for both methods. RESULTS: C-arm CT fluoroscopy resulted in a reduced number of transhepatic punctures, with decreased procedure and fluoroscopy times (P < .05; t test). When compared with conventional external biliary drainage procedures, a mean of 1.8+/-1 versus 4.8+/-2.8 hepatic punctures at a fluoroscopy time of 3.4+/-1.5 versus 11.4+/-7.4 minutes was required for C-arm CT fluoroscopy, while procedure times were 11+/-3.6 versus 16.2+/-9.3 minutes. CONCLUSIONS: C-arm CT fluoroscopy is associated with decreased procedure and fluoroscopy times, while fewer transhepatic punctures are required to establish external biliary drainage.

Adolescent↗

PubMed2003

Prospective comparison of virtual fluoroscopy to fluoroscopy and plain radiographs for placement of lumbar pedicle screws.

Fluoroscopy-based frameless stereotactic systems provide feedback to the surgeon using virtual fluoroscopic images. The real-life accuracy of these virtual images has not been compared with traditional fluoroscopy in a clinical setting. We prospectively studied 23 consecutive cases. In two cases, registration errors precluded the use of virtual fluoroscopy. Pedicle probes placed with virtual fluoroscopic imaging were imaged with traditional fluoroscopy in the remaining 21 cases. Position of the probes was judged to be ideal, acceptable but not ideal, or not acceptable based on the traditional fluoroscopic images. Virtual fluoroscopy was used to place probes in for 97 pedicles from L1 to the sacrum. Eighty-eight probes were judged to be in ideal position, eight were judged to be acceptable but not ideal, and one probe was judged to be in an unacceptable position. This probe was angled toward an adjacent disc space. Therefore, 96 of 97 probes placed using virtual fluoroscopy were found to be in an acceptable position. The positive predictive value for acceptable screw placement with virtual fluoroscopy compared with traditional fluoroscopy was 99%. A probe placed with virtual fluoroscopic guidance will be judged to be in an acceptable position when imaged with traditional fluoroscopy 99% of the time.

Adult↗

PubMed1998

Patient and staff radiation dose in fluoroscopy-guided TIPS procedures and dose reduction, using dedicated fluoroscopy exposure settings.

Fluoroscopy guided interventions, such as transjugular intrahepatic portosystemic shunt (TIPS) procedures, can results in relatively high radiation doses to patients and staff. The purpose of this study was to evaluate the possible benefit of dedicated fluoroscopy exposure factors in the reduction of doses. Doses to patients and staff were measured during fluoroscopy-guided TIPS procedures in two Dutch university hospitals. Patient doses were calculated from dose-area product (DAP) measurements, entrance beam dimensions and DAP conversion factors. Staff doses were measured outside lead aprons using electronic personal dosemeters. Average patient entrance skin dose (ESD) rate during fluoroscopy was 49 mGy min-1 (13 cases, average fluoroscopy duration 32 min) in one hospital, and 6 mGy min-1 (10 cases, average fluoroscopy duration 50 min) in the other. Estimated staff effective dose per procedure was 28 microSv average in the first hospital compared with 4 microSv average in the other. The use of dedicated fluoroscopy exposure factors, with a relatively high tube voltage and lower tube current resulted in a significant dose reduction for patient and staff in this type of radiological intervention.

Fluoroscopy↗

PubMed2000

Dose reduction in gastrointestinal and genitourinary fluoroscopy: use of grid-controlled pulsed fluoroscopy.

OBJECTIVE: We evaluated the diagnostic accuracy of a grid-controlled fluoroscopy unit compared with a conventional continuous fluoroscopy unit for a variety of abdominal and pelvic fluoroscopic examinations. SUBJECTS AND METHODS: Seventy patients (29 men and 41 women; age range, 24-78 years) were enrolled in one of seven abdominal and pelvic fluoroscopic examinations, including upper gastrointestinal series (n = 20), barium enema (n = 10), voiding cystourethrogram (n = 10), percutaneous abdominal catheter tube injection (n = 10), hysterosalpingogram (n = 10), and percutaneous needle insertion and catheter placement (nephrostomy, percutaneous biliary drainage) (n = 10). Each patient underwent at least 10 sec of continuous fluoroscopy that was randomly and blindly compared with 10-sec periods of pulsed fluoroscopy at 15, 7.5, and 3.75 frames per second. A radiologist outside the examination room, unaware of the frame rate per second, evaluated the procedure in real time on a television monitor. The radiologist assessed image quality and diagnostic acceptability using a scoring system. Statistical analysis was performed using the paired Student's t test. RESULTS: For all procedures at all frame rates, we found no statistically significant superiority of one frame rate over another. For most procedures, the slower frame rates were considered equivalent to continuous fluoroscopy when the images were assessed for image quality and diagnostic confidence. CONCLUSION: Our findings suggest that most abdominal and pelvic fluoroscopic procedures can be performed at substantially lower frame rates than those used for continuous fluoroscopy; adopting this procedure may lead to substantial dose savings for the patient and the fluoroscopy operator.

Adult↗

PubMed2005

An anatomical study comparing standard fluoroscopy and virtual fluoroscopy for the placement of C1-2 transarticular screws.

OBJECT: The authors sought to compare radiation exposure, surgical time, and accuracy of screw placement when using either standard fluoroscopy or virtual fluoroscopy for the placement of C1-2 transarticular screws. METHODS: Twenty-two C1-2 transarticular screws were placed in 11 cadavers in a randomized and alternating order by using either standard fluoroscopy or virtual fluoroscopy (fluoronavigation). The radiation time, procedure time, and accuracy of screw placement were recorded and statistically compared. A small but statistically significant reduction in fluoroscopy time was noted with the virtual fluoroscopy technique but the surgical times were similar between the two techniques. The incidence of noncritical and critical breaches (those at risk of causing a neurovascular injury) was not significantly different between the two groups. Careful analysis of the C1-2 anatomy in these specimens underscored the importance of placing the screw path in a maximally dorsal and medial portion of the C-2 isthmus to avoid injury to the vertebral artery and to maximize the bone purchase of the C-1 lateral mass. CONCLUSIONS: Although virtual fluoroscopy may represent a useful tool for transarticular screw placement, it does not supplant traditional surgical techniques and does not appear to lower the incidence of bone breaches that can occur when performing this demanding procedure.

Bone Screws↗

PubMed2005

A cadaveric study comparing standard fluoroscopy with fluoroscopy-based computer navigation for screw fixation of the odontoid.

Although direct osteosynthesis of certain types of odontoid fractures may increase union and decrease the need for prolonged immobilization, screw fixation remains a technically demanding procedure. This study compares radiation exposure, surgical time, and accuracy of hardware placement using standard fluoroscopy versus computer-assisted fluoroscopy-based navigation ("virtual fluoroscopy") to assist with the placement of odontoid screws. Twenty-two cadavers were divided into two groups and underwent placement of a single odontoid screw using either standard fluoroscopic or virtual fluoroscopic guidance. Following screw placement, dissection of the C1-C2 segments was performed to assess accuracy. A significant reduction in fluoroscopy time was noted with the computer-based fluoroscopy technique, whereas the surgical time was not found to differ significantly between the techniques. No critical breaches (those risking neurovascular injury) were noted in either group, and the rate of noncritical breaches did not differ. The authors conclude that fluoroscopy-based virtual navigation appears to have a safety profile similar to standard fluoroscopy while allowing a reduction in radiation exposure.

Bone Screws↗

PubMed2004

[Evaluation of percutaneous vertebroplasty in osteoporotic vertebral fractures using a combination of CT fluoroscopy and conventional lateral fluoroscopy].

PURPOSE: Evaluation of vertebroplasty using a combination of CT-fluoroscopy and conventional lateral fluoroscopy in patients with osteoporotic vertebral fractures. MATERIALS AND METHODS: Fifty-eight patients (23male, 35 women, age 69.7 +/- 10.2 years) with painful osteoporotic vertebral fractures were treated with vertebroplasty in conscious sedation and local anesthesia. Spiral-CT with sagittal reconstructions of the respective vertebral bodies was used for classification of the fracture. The cannula was placed under CT-guidance in the ventral third of the respective vertebral bodies and cement instilled under CT fluoroscopy and lateral fluoroscopy. When cement migrated towards the vertebral canal, the injection was immediately stopped for 30 - 60 seconds. After polymerization in this location, the injection was continued until sufficient filling of the vertebra. Results were documented by spiral CT with sagittal reconstructions. RESULTS: A total of 123 vertebral bodies were treated, comprising 39 thoracic and 84 lumbar vertebral bodies, with a mean of 2.1 +/- 1.3 (range 1 to 6) vertebral bodies in each patient and a maximum of 3 vertebral bodies per session. All interventions were successfully completed in conscious sedation and local anesthesia. A mean volume of 5.9 +/- 0.6 ml (range 2 to 14 ml) cement was applied for each vertebra, with 79.7 % of procedures performed using a unilateral access. To achieve a sufficient cement deposit, a bilateral access was used in 20.3 %. The dorsal wall of the vertebra was included in 23.6 % of the fractures. In one case, cement migration into the spinal canal was detected, reducing the diameter of the canal by 30 %. In two other cases, cement leakage was seen at the puncture site of the vertebra (one intercostotransversally in the 10 (th) thoracic vertebra and one dorsolaterally in the 1 (st) lumbar vertebra) with retrograde cement migration through the neuroforamen into the epidural space. In one of these cases, the cannulation of the vertebra had been changed before cement application resulting in a hole in the dorsolateral vertebral wall. However, all patients were discharged without evidence of neurologic complications. Multiplanar reconstructions of CT scans were used for the detection of extraosseous cement leaks: The incidence of extraosseous cement leaks was 4.1 % in epidural veins, 6.5 % in paravertebral vessels (6 veins, 2 arteries), and 17.9 and 11.4 %, respectively, for upper or lower end plates. At discharge, 25 patients (43.1 %) were free of pain and 28 (48.3 %) significantly improved with a considerable reduction of analgetic drugs. Significant complaints persisted in 5 patients (8.6 %) with concomitant degenerative disease in four and vasculitis in one case. CONCLUSION: Percutaneous vertebroplasty is effective for stabilization and pain management of osteoporotic vertebral fractures. The procedure can be safely performed in conscious sedation and local anesthesia. Compared to conventional fluoroscopy alone, CT fluoroscopy provides an excellent additional monitoring of the procedure and probably contributes to the safety of the procedure.

Adult↗

PubMed2006

Initial experience with magnetic resonance fluoroscopy in the evaluation of oesophageal motility disorders. Comparison with manometry and barium fluoroscopy.

The aim of this paper was to assess the diagnostic value of magnetic resonance (MR) fluoroscopy in the study of oesophageal motility disorders and to compare MR fluoroscopy results with those of manometry and barium contrast radiography. Twenty-five subjects referred for dysphagia and three patients in follow-up after pneumatic dilatation of the lower oesophageal sphincter to treat severe achalasia underwent esophageal manometry, barium contrast radiography and MR fluoroscopy. Examinations were performed on a 1.5 T scanner. Dynamic turbo- fast low angle shot (turbo-FLASH) sequences acquired during oral contrast agent administration were used to perform MR fluoroscopy. MR fluoroscopy correctly diagnosed achalasia in nine patients, uncoordination of esophageal body motility in ten and scleroderma oesophagus in one. Diagnostic performance was satisfactory, with a sensitivity of 87.5% and a specificity of 100% in the general depiction of motility alterations. Our work demonstrates that MR fluoroscopic examination in subject affected by oesophageal motility disorders is feasible and can properly depict motility and morphology alterations, achieving correct diagnosis in the majority of cases. Studies on larger populations are necessary to obtain statistically significant results.

Adult↗

PubMed1968