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At least 19 recordsLinked to original sources
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↗
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↗
PubMed1996

Reduction of radiation dose in pediatric patients using pulsed fluoroscopy.

OBJECTIVE: The purpose of this study was to determine if pulsed fluoroscopy reduces radiation exposure to pediatric patients undergoing conventional fluoroscopy. SUBJECTS AND METHODS: Four hundred one consecutive patients were nonrandomly divided into pulsed fluoroscopy and conventional fluoroscopy study groups. Two control groups were also assembled: 474 patients evaluated with conventional fluoroscopy before the study and 138 patients evaluated with pulsed fluoroscopy after the study. RESULTS: We found no difference in fluoroscopy times across the groups. Although the number of digital spot films was slightly higher for the pulsed fluoroscopy study group than for the conventional fluoroscopy study group, we found no difference in the number of digital spot films for the pulsed fluoroscopy study group and for the conventional fluoroscopy control group. Furthermore, the difference in the number of digital spot films was also insignificant for the pulsed fluoroscopy control group and the conventional fluoroscopy study group. The radiation exposure in the pulsed fluoroscopy study group was 50% lower (mean, 0.6 R) than in the conventional fluoroscopy study group. When using pulsed fluoroscopy in the 7.5 pulses-per-second mode, we were able to reduce radiation exposure by 75% of that from conventional fluoroscopy. CONCLUSION: Pulsed fluoroscopy reduces fluoroscopic radiation exposure to pediatric patients undergoing conventional fluoroscopy. Despite minor image degradation, pulsed fluoroscopy is the technique of choice at our institution.

Arthrography↗
PubMed1996

[Initial experiences with pulsed fluoroscopy on a multifunctional fluoroscopic unit].

PURPOSE: Comparison of radiation doses in pulsed and continuous fluoroscopy to quantify the dose reduction by pulsed fluoroscopy. Further, the applicability of pulsed fluoroscopy in clinical routine has been evaluated. MATERIALS AND METHODS: In a human pelvic phantom, the radiation dose (skin entry dose in cGycm2) was measured at two pulses per second (pps), 3 pps, 6 pps, 12 pps and continuous fluoroscopy mode, respectively, using image-intensifier entries of 38 cm, 25 cm, and 17 cm. 300 examinations were carried out, and the results of the different fluoroscopy modes were registered. RESULTS: Dose reduction depends on the image-intensifier entry. Compared to the radiation dose in continuous fluoroscopy, with 12 pps fluoroscopy the radiation dose can be reduced at a minimum of 51%, with 6 pps fluoroscopy to 40%, with 3 pps fluoroscopy to 20%, and with 2 pps fluoroscopy to a minimum of 14.5%. Clinical routine has shown that 78% of all examinations can be performed with 2 or 3 pps fluoroscopy mode. In 12.7% of the cases pulsed fluoroscopy of diverse frequencies was used, in an additional 2% combined with continuous fluoroscopy. Exclusively, continuous fluoroscopy has been employed in 2% of the cases. CONCLUSIONS: Using pulsed fluoroscopy, an 80% reduction of the radiation dose compared to continuous fluoroscopy is possible. About 96% of all examinations can be performed with pulsed fluoroscopy of different pulse rate and without using continuous fluoroscopy.

Diagnostic Tests, Routine↗
PubMed1989

Fluoroscopy in colonoscopy. Who is using it and why?

Use of fluoroscopy during colonoscopy has never been broadly assessed. A survey of 1,864 members of the Society of American Gastrointestinal Endoscopic Surgeons and the American Society of Colon and Rectal Surgeons was carried out to quantify the use of fluoroscopy and to elicit impressions regarding its capabilities, indications, and usefulness. After the establishment of the responding colonoscopist's training, experience, and other background data, impressions of fluoroscopy's role in many issues were obtained using a graded response system. Concluding the two-page survey were open-ended questions addressing the respondent's indications, contraindications, and rationale for using or not using fluoroscopy. Six hundred thirty-one colonoscopists responded. Seventy-five per cent never use fluoroscopy; the most frequently cited reasons were lack of need and inaccessibility of fluoroscopy. For many colonoscopists, fluoroscopy is unavailable (22%) or available outside of the usual endoscopy setting (44%). Fluoroscopy is used by 25 per cent of colonoscopists. Almost three quarters of this group have the capability of performing fluoroscopy in their colonoscopy unit. The indications for fluoroscopy varied with the frequency of its use; frequent users employ fluoroscopy to treat loops, to confirm cecal intubation, and to locate the instrument tip precisely. Infrequent users employ fluoroscopy to apply the sigmoid straightening overtube or because of prior failed colonoscopy. Impressions regarding the impact of fluoroscopy on learning, completing, and safeguarding colonoscopy were obtained. Most colonoscopists are satisfied without using fluoroscopy, although 65 per cent of nonusers believe it would improve colonoscopy performance if it were used. Ninety-two per cent of frequent users of fluoroscopy reported that they would feel significantly impaired without having the capability to perform fluoroscopy.(ABSTRACT TRUNCATED AT 250 WORDS)

Colonoscopy↗
PubMed1998

Reduction of radiation exposure time during catheter ablation with the use of pulsed fluoroscopy.

UNLABELLED: Prolonged exposure to radiation during radiofrequency catheter ablation implies a potential risk of radiodermatitis, neoplasm and genetic defects to the patient and to the operator-physician. The use of pulsed fluoroscopy is thought to reduce such a risk because the radiation dose decreases for the same period of time. The aim of the present study was to compare the radiation exposure time during pulse and continuous radiofrequency catheter ablation. METHODS: Procedures were divided according to the sort of fluoroscopy utilized and the last four cases of atrioventricular (AV) junction ablation, four of atrial flutter, five of atrial tachycardia, 16 of AV node reentrant tachycardia, 16 of AV tachycardia and 10 of ventricular tachycardia in which pulsed and continuous fluoroscopy were utilized were respectively separated into Group I (pulse fluoroscopy) and Group II (continuous fluoroscopy) with 55 patients in each group. Fluoroscopy was generated by the same device in the two groups. Continuous fluoroscopy used 2 mA and automatic kV adjustment (automatic brightness stabilizer) ranging from 70 to 110 kV. Pulsed fluoroscopy was set at 7 squares/s with 25 mA and automatic kV adjustment. Fluoroscopy time was registered by the fluoroscopy device counter. RESULTS: Procedure duration, success rate and complications did not differ between Groups I and II. Fluoroscopy time, however, was 4.4+/-4 min during pulsed fluoroscopy and 27+/-23 min during continuous fluoroscopy (p=0.001). CONCLUSION: During radiofrequency catheter ablation procedures, the use of pulsed fluoroscopy set at 7 squares/s, decreases the radiation exposure time by 80% as compared to continuous fluoroscopy without changing procedure duration and success rate.

Cardiac Catheterization↗
PubMedDate not supplied

Feasibility of C-arm-supported CT fluoroscopy in percutaneous abscess drainage procedures.

PURPOSE: Evaluation of C-arm-supported CT fluoroscopy to facilitate percutaneous abscess drainage procedures. METHODS: Prospectively, 40 percutaneous drainage procedures were performed either with C-arm-supported CT fluoroscopy or with CT fluoroscopy alone. Hybrid imaging was performed on the CT couch after complementing a CT fluoroscopy scanner with a C-arm fluoroscopy unit. Procedure times, drainage revisions during follow-up, and postinterventional drainage periods were analyzed. RESULTS: When compared with exclusive CT fluoroscopic guidance, a median procedure time of 9 +/- 3.7 min versus 14.8 +/- 7.3 min was required for C-arm-supported CT fluoroscopy (p < 0.005, t-test). During follow-up, eight drainage catheters had to be revised within the exclusive CT fluoroscopy group, while only two revisions were necessary within the C-arm-supported CT fluoroscopy group. With C-arm-supported CT fluoroscopy, postinterventional drainage periods were reduced (median 13 vs 19 days; p < 0.001, t-test). CONCLUSION: Compared with exclusive cross-sectional image guidance, C-arm-supported CT fluoroscopy seems to improve placement of abscess drainage catheters to possibly reduce procedure times, drainage catheter revisions, and postinterventional drainage periods.

Abscess↗
PubMed1985

Digital subtraction fluoroscopy: a new method of detecting coronary calcifications with improved sensitivity for the prediction of coronary disease.

The association between calcification of the coronary arteries and coronary artery narrowing is well established. However, fluoroscopic visualization of coronary calcifications has been insufficiently sensitive to be useful as a screening test. Since digitization of radiographic images permits the subtraction of noncardiac structures from moving cardiac structures, such subtraction might increase the sensitivity of coronary fluoroscopy. To determine whether coronary calcifications were better visualized with digital subtraction fluoroscopy than with conventional fluoroscopy, we taped diseased human coronary arteries to a pulsating water balloon inside the thorax of a dog cadaver and studied this model with both fluoroscopic techniques. Calcific atherosclerotic plaques were more easily identified with digital subtraction fluoroscopy than with conventional fluoroscopy. We tested the method clinically by submitting 191 subjects without history or electrocardiographic evidence of previous myocardial infarction who were referred for coronary arteriography to both fluoroscopic studies. For at least one, at least two, and three calcified coronary arteries, digital fluoroscopy was more sensitive (92%, 66%, and 40%) than conventional fluoroscopy (63%, 21%, and 2%) (all p less than .001) for the prediction of significant coronary obstructions (greater than 50%). Although digital fluoroscopy was less specific than conventional fluoroscopy (digital: 65%, 89%, and 97%; conventional: 81%, 98%, and 100%) (all but last, p less than .01), receiver operating curve analysis revealed a significantly larger area under the curve, indicating higher accuracy for the digital technique (p = .03). Digital subtraction fluoroscopy was more accurate in younger than in older patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1996

Fluoroscopy. A valuable ally during difficult colonoscopy.

BACKGROUND: This study determines the pattern of fluoroscopy use during colonoscopy among a group of gastroenterologists and colon and rectal surgeons who have it readily available for each patient. METHODS: One thousand three hundred fifty-seven consecutive patients undergoing colonoscopic examination were studied over a 16-month period. RESULTS: Fluoroscopy was used during 34% of colonoscopic examinations. The frequency of fluoroscopy use was significantly higher for women (41% vs 28%, p < 0.001). Fluoroscopy was most commonly used to precisely locate the colonoscope tip (45%) or during manipulation of troublesome loops of colon (42%), thus accounting for 87% of 677 fluoroscopic checks. The most common location of the colonoscope tip during these fluoroscopic checks was the hepatic flexure (23%) followed by the cecum (20%); 51% involved the right colon. The selective use of fluoroscopy during the more difficult cases was substantiated by the longer procedure time (36 vs 26 min) and significantly lower cecal intubation rate (74% vs 96%, p < 0.002) when fluoroscopy was required. Fluoroscopy also proved to be valuable when precisely locating pathology and teaching colonoscope intubation techniques. CONCLUSIONS: Endoscopists who have fluoroscopy readily available often use it during difficult colonoscopic examinations. Fluoroscopy is most commonly used to maneuver troublesome loops of colon or to precisely locate colonoscope tip position, especially when negotiating the right colon. Although this technology is more frequently required for women, fluoroscopic capability for all colonoscopic examinations is advantageous.

Adolescent↗