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Percutaneous radiofrequency lumbar facet rhizotomy guided by computed tomography fluoroscopy.

X-ray fluoroscopy-guided percutaneous radiofrequency facet rhizotomy is used to treat chronic low back pain. The traditional fluoroscopic approach to the medial branch of the posterior rami, however, is associated with a small incidence of complications. We describe a new method for radiofrequency lumbar facet rhizotomy in which computed tomography (CT) fluoroscopy is used to guide needle placement. Three patients with chronic intractable low back pain underwent CT fluoroscopy-guided percutaneous facet rhizotomy. After the safest and shortest route to the target site was determined on the CT image, the needle was advanced along the predetermined route under real-time CT fluoroscopy. When the needle tip was located at the target site, electrical stimulation was applied to verify proper electrode placement. After confirming the clinical effect and lack of complications under test block with a local anesthetic, denervation was performed using radiofrequency current. Pain scores of all patients were reduced after the procedure without any complications such as paralysis or neuritic pain. None of the patients complained of severe discomfort during the procedure. CT fluoroscopy-guided percutaneous lumbar facet rhizotomy appears to be safe, fast, and effective for patients with lumbar facet pain.

Aged↗

Thermogangliolysis of the Gasserian ganglion under computed tomography fluoroscopy.

Gasserian ganglion block is an established treatment for trigeminal neuralgia. A landmark approach assisted by X-ray fluoroscopy is the most common method; however, visualization of the foramen ovale is difficult in some cases. Here we report two cases in which a novel technique using modern computed tomography (CT) fluoroscopy was employed. A 63-year-old woman suffering pain in the maxillary nerve area was treated by thermogangliolysis under CT fluoroscopy. The patient was positioned on a CT stage with the head in an overhanging position. The CT gantry was set at an oblique angle to obtain a coronal view of the foramen ovale. The safest and shortest route to the foramen was designed using the CT image and a 22-gauge insulated needle was advanced following the designed route under CT fluoroscopy. The effect of the nerve block was estimated by injection of a test dose of mepivacaine, after which the ganglion was thermally coagulated at 90 degrees C. Satisfactory analgesia was obtained in this case without any complications. Another patient (65 years old) was also treated by the same technique, and satisfactory pain relief was obtained. In conclusion, CT fluoroscopy-guided Gasserian ganglion thermolysis is considered a safe, quick, and effective treatment for trigeminal neuralgia.

Aged↗

Comparison of stress digital ventriculography, stress thallium scintigraphy, and digital fluoroscopy in the diagnosis of coronary artery disease in subjects without prior myocardial infarction.

Exercise thallium scintigraphy is often used for the diagnosis of coronary artery disease (CAD). Exercise digital subtraction ventriculography and digital subtraction fluoroscopy are new diagnostic procedures with roles that have not been determined. To compare the relative accuracies of the digital techniques with thallium scintigraphy, 97 consecutive patients without myocardial infarction underwent all 3 tests on the day before their scheduled coronary angiograms. Forty-two patients had CAD (more than 50% diameter narrowing of 1 major artery). A fixed or reversible perfusion defect defined an abnormal thallium test response and a segmental wall motion abnormality at rest or with exercise defined an abnormal digital ventriculographic response. Any visualized coronary calcific deposit defined an abnormal digital fluorographic response. The sensitivities of digital fluoroscopy (86%) and digital ventriculography (79%) were significantly higher than the sensitivity of thallium (62%) (p less than 0.05). The specificity of thallium (82%) was not significantly higher than that of either digital ventriculography (72%) or fluoroscopy (67%). The diagnostic accuracies of digital fluoroscopy, digital ventriculography, and thallium were 75%, 75% and 73%, respectively. A logistic regression model showed that thallium and digital fluoroscopy were more accurate in younger patients, whereas digital ventriculography was more sensitive in hypertensive persons and in those not taking beta-blocking drugs. The choice of test depends on disease prevalence, clinical variables (such as age and hypertension) and the importance of functional information obtained from stress testing.

Age Factors↗

Sensitivity of chest fluoroscopy compared with chest CT and chest radiography for diagnosing hydropneumothorax in association with percutaneous nephrostolithotomy.

OBJECTIVES: Hydropneumothorax (HPTX) is recognized as a potential complication of percutaneous nephrostolithotomy (PCNL), particularly with supracostal access. Postoperative chest radiography (CXR) is routinely used to evaluate the chest after PCNL. We prospectively compared the sensitivity of intraoperative chest fluoroscopy with immediate postoperative portable CXR and postoperative day 1 chest computed tomography (CT) for the detection of pleural fluid. METHODS: A total of 89 consecutive patients (mean age 47.9 +/- 13.3 years; 100 renal units) undergoing PCNL were prospectively evaluated with intraoperative fluoroscopy at the conclusion of the procedure and then with anteroposterior CXR in the postanesthesia care unit and postoperative day 1 noncontrast, thin-cut CT of the kidneys and lung bases. CT imaging of the lung bases comprised the reference standard for detecting pleural fluid. RESULTS: A total of 104 percutaneous renal accesses in 100 renal units, 60 above and 44 below the 12th rib, were used. In 16 cases (16%), a second-stage procedure was performed to clear residual stone fragments detected on post-PCNL CT. HPTX was detected in 1, 8, and 38 cases by initial fluoroscopy, immediate postoperative CXR, and CT scan, respectively. Intervention was necessary in 7 patients. In 2 patients with fluoroscopic evidence of pleural fluid (1 at the initial PCNL and 1 during second-look flexible nephroscopy), intraoperative pleural drainage was performed percutaneously. In the other 5 patients, intervention was determined by the size of the HPTX on chest CT scan (n = 1) or the presence of symptoms (n = 4). In no case was intervention performed on the basis of the immediate postoperative CXR findings when intraoperative chest fluoroscopy was negative. CONCLUSIONS: Intraoperative chest fluoroscopy during PCNL is sufficient to detect clinically significant HPTXs, and, therefore, routine postoperative CXRs are not necessary. However, a high index of suspicion based on clinical symptoms postoperatively should prompt chest imaging.

Adult↗

Predictors of fluoroscopy time and estimated radiation exposure during radiofrequency catheter ablation procedures.

The objective of this study was to identify factors that predict fluoroscopy duration and radiation exposure during catheter ablation procedures. The patient population included 859 patients who participated in the Atakr Ablation System clinical trial at 1 of 9 centers (398 male and 461 female patients, aged 36 +/- 21 years). Each patient underwent catheter ablation of an accessory pathway, the atrioventricular junction, or atrioventricular nodal reentrant tachycardia using standard techniques. The duration of fluoroscopy was 53 +/- 50 minutes. Factors identified as independent predictors of fluoroscopy duration included patient age and sex, the success or failure of the ablation procedure, and the institution at which the ablation was performed. Catheter ablation in adults required longer fluoroscopy exposure than it did in children. Men required longer durations of fluoroscopy exposure than did women. The mean estimated "entrance" radiation dose was 1.3 +/- 1.3 Sv. The dose needed to cause radiation skin injury was exceeded during 22% of procedures. The overall mean effective absorbed dose from catheter ablation procedures was 0.025 Sv for female patients and 0.017 Sv for male patients. This degree of radiation exposure would result in an estimated 1,400 excess fatal malignancies in female patients and 2,600 excess fatal malignancies in male patients per 1 million patients.

Adolescent↗

CT fluoroscopy-guided percutaneous needle biopsies in thoracic mass lesions.

OBJECTIVE: We aimed to evaluate the usefulness of computed tomographic (CT) fluoroscopy guidance for transthoracic needle biopsies. METHODS AND MATERIAL: CT fluoroscopy-guided biopsies were performed in 81 patients with thoracic mass lesions. Interrupted CT fluoroscopy technique was used with 50-130 mA at 120 kV exposure parameters and slice thickness of 10 mm. We used aspirating needle in 41 patients, cutting needle in 28 patients, and both in 12 patients. We obtained adequate biopsy material in 69 patients at first attempt. Mean fluoroscopy time was 15.17 s and maximum procedure time was 18 min. RESULTS: Adequate samples for pathological diagnosis were obtained in all lesions. Pathological diagnoses were malignant in 41 patients, benign in 27 patients, and suspiciously malignant in 13 patients. There was no significant difference between diagnostic accuracy of the needles in malignant and benign lesions. Complications were observed in 11 patients (13.5%). DISCUSSION AND CONCLUSION: CT fluoroscopy-guided technique provides effective real-time needle biopsy in patients with small tumor size and with tumor located near blood vessels, and in non-compliant patients for diagnosing thoracic lesions.

Adult↗

Effect of the learning process on procedure times and radiation exposure for CT fluoroscopy-guided percutaneous biopsy procedures.

PURPOSE: To assess if the learning process associated with computed tomography fluoroscopy (CTF) technology influences procedure and fluoroscopy times for percutaneous biopsy procedures. MATERIALS AND METHODS: Prospective analysis of the initial 250 consecutive patients who underwent percutaneous biopsy with use of a CT scanner equipped with rapid image reconstruction and fluoroscopic capabilities in a 24-month period. All procedures were performed with both continuous and spot fluoroscopic technique, with typical radiation parameters of 50 mA, 120 kV, and a 10-mm-slice thickness. The procedures were all performed by a single experienced interventional radiologist to limit the variables of physician expertise, interventional materials used, and biopsy approach. The subject group was divided into five equal consecutive groups of 50 patients. In each subgroup, the authors recorded mean lesion size, success, and complication rates, as well as mean procedure and fluoroscopy times. RESULTS: The five subgroups were similar patient populations as documented by the absence of statistically significant differences when comparing mean lesion size, procedure success, and complication rates (P > .05; ANOVA test). A statistically significant decrease in mean fluoroscopy (groups 1-5: 50.26 vs 45.24 vs 33.86 vs 32.68 vs 25.8 sec/patient) and mean procedure times (groups 1-5: 30.08 vs 27.9 vs 26.34 vs 25.6 vs 21.6 min/patient) was recorded between the patient subgroups (P < .0001; ANOVA test). CONCLUSION: The learning process associated with CTF technology impacts procedure parameters by decreasing both mean procedure and fluoroscopy times, thereby increasing patient turnover and decreasing radiation exposure to the patient and the operator.

Adult↗

Exclusion of fluoroscopy during ablation treatment of right accessory pathway in children.

INTRODUCTION: The field of pediatric electrophysiology poses many challenges to electrophysiologists. In particular there are two major concerns: (1) to reduce the amount of fluoroscopy exposure to patients and medical staff in the catheterization laboratory and (2) to minimize the number of vascular accesses. Prolonged fluoroscopy times are associated with radiofrequency (RF) ablation of right accessory pathways (APs), particularly the right free-wall AP. The aim of this study was to eliminate the use of fluoroscopy during treatment of right-sided APs in children while using a single-catheter approach. METHODS AND RESULTS: We studied 21 consecutive pediatric patients (mean age 11.3 +/- 3.2 years) with Wolff-Parkinson-White syndrome due to a right AP. To limit fluoroscopy use, we used a three-dimensional navigation system that facilitated reconstruction of a three-dimensional electroanatomic activation map along the tricuspid annulus either on the atrial side during orthodromic AV reciprocating tachycardia or along the ventricular side during anterograde preexcitation. RF application was successful and without complications in 20 patients (success rate 95%); moreover, 19 of the 21 patients underwent a single-catheter procedure. The remaining two patients required an additional quadripolar catheter for atrial stimulation. A mean of 2 +/- 1 RF applications were used during the whole study. CONCLUSION: Our study demonstrates that ablation of right APs in children can be performed without fluoroscopy using a single catheter with minimal amounts of RF applications. Our new technique is associated with high success rates.

Accessory Nerve↗

Electrical isolation of pulmonary veins in patients with atrial fibrillation: reduction of fluoroscopy exposure and procedure duration by the use of a non-fluoroscopic navigation system (NavX).

AIMS: The aim of the study was to investigate the feasibility of performing segmental pulmonary vein (PV) isolation guided by the NavX (Endocardial Solutions, St Jude Medical, Inc., St Paul, MN, USA) system without the three-dimensional (3D) geometric reconstruction option and whether the use of NavX system will reduce the radiation exposure and procedure duration. METHODS AND RESULTS: The study included 64 patients with symptomatic paroxysmal or permanent atrial fibrillation, in whom PV isolation was performed using fluoroscopic guidance (n=32) or the NavX system (n=32). Pulmonary vein mapping with a circular mapping catheter allowed the identification and localization of myocardial connections between the PV and the left atrium. PV isolation was performed by radiofrequency ablation of these connections at the atrial aspect of the PV ostium. Primary success rate for isolated PVs did not differ significantly in patients ablated under fluoroscopic guidance vs. those ablated under guidance of NavX system [100/107 PVs (93.5%) vs. 120/124 PV (96.8%; P=n.s.)]. Compared with fluoroscopy guided procedures, NavX-guided procedures showed a significant reduction in the fluoroscopy time (75.8+/-24.5 vs. 38.9+/-19.3 min, P<0.05), total X-ray exposure (93.2+/-51.6 vs. 56.6+/-37.9 Gy cm(2), P=0.03), and total procedural time (237.7+/-65.4 vs. 188.6+/-62.7 min, P=0.01). The mean follow-up was 9.5+/-3.0 months. One patient in each group was lost to follow-up. Seven-day Holter monitoring showed that 23 of 31 patients (74.2%) in the NavX-guided group and 21 of 31 patients (67.7%) in the fluoroscopy-guided group were in sinus rhythm (P=0.57). CONCLUSION: The 3D visualization of the catheters by NavX system allows a rapid and precise visualization of the mapping and ablation catheters at the PV ostia and markedly reduces fluoroscopy time, total X-ray exposure, and procedural duration during PV isolation compared with ablation performed under fluoroscopy guidance.

Aged↗

Intraoperative fluoroscopy to evaluate fracture reduction and hardware placement during acetabular surgery.

OBJECTIVES: To evaluate use of intraoperative fluoroscopy during acetabular surgery to determine fracture reduction and accurate placement of screws. DESIGN: Retrospective. SETTING: Level I trauma center. PARTICIPANTS: Thirty patients with thirty-two acetabular fractures. INTERVENTION: Patients were evaluated with fluoroscopy during surgery to assess fracture reduction and screw placement. Anterior-posterior (AP), oblique, and lateral pelvic fluoroscopic images were obtained intraoperatively. Postoperative radiographs were used to verify fluoroscopic findings; computed tomography (CT) scans were used as the control to assess intraarticular screw placement. MAIN OUTCOME MEASUREMENTS: Radiographic and clinical assessment of fracture reduction and screw placement. RESULTS: Intraoperative fluoroscopy confirmed the extra-articular position of all screws evaluated. Postoperative CT scans confirmed the extra-articular placement of all screws assessed by fluoroscopy. Quality of reduction using intraoperative fluoroscopic images had a 100 percent correlation with reduction on final radiographs. One patient, with two screws placed without fluoroscopic evaluation, had intra-articular placement requiring revision surgery. CONCLUSIONS: Intraoperative fluoroscopy is effective in evaluating both acetabular fracture reduction and hardware placement.

Acetabulum↗

Port-A-Cath placement without the aid of fluoroscopy or localizing devices: a community hospital series.

BACKGROUND: Traditionally, Port-A-Caths are placed with the aid of intraoperative fluoroscopy or other localizing devices. Confirmation of catheter placement and location are made intraoperatively, and this practice adds considerable cost to the overall procedure with questionable benefit. We examined the experience of a community surgeon who does not use fluoroscopy or localizing devices to see whether this complication rate or need for manipulation of the catheter was high as well as cost savings per case. METHODS: A retrospective review of 107 Port-A-Caths cases were evaluated for patient age, indication for port placement, sex, pneumothorax, need for repositioning of catheter, access site, catheter tip location, need for operative intervention related to port placement, and death. Location of the catheter was confirmed by dictated chest x-ray results and need for repositioning by the surgeon's operative note. Cost of fluoroscopy as well as C-arm use and chest x-ray studies were also used to calculate savings. RESULTS: Of the 107 Port-a-Cath cases, two (1.9%) pneumothoraces occurred and two (1.9%) catheters were repositioned; no deaths and no operative interventions related to Port-a-Cath placements occurred. Seventy-six (71%) of the ports were accessed via a left subclavian approach, and the remainder were accessed via right subclavian, right internal jugular, left internal jugular, and external jugular approaches. One catheter was repositioned due to a kink noted on postoperative chest x-ray study, and the other was noted to be ascending the left internal jugular vein. Cost of the C-arm was USD 174 for less than 1 hour and for fluoroscopy was USD 396 for less than 1 hour. CONCLUSION: In our study, only two catheters (1.9%) needed to be repositioned. This comes at an estimated savings of USD 40,000 for this series. Based on our experience, Port-A-Caths can be placed safely without fluoroscopy or localization devices with no added morbidity and significant cost savings to the patient.

Catheterization, Central Venous↗

Standard multiplanar fluoroscopy versus a fluoroscopically based navigation system for the percutaneous insertion of iliosacral screws: a cadaver model.

OBJECTIVES: To compare the safety and efficiency of standard multiplanar fluoroscopy (StdFluoro) and virtual fluoroscopy (VirtualFluoro) for use in the percutaneous insertion of iliosacral screws. DESIGN: : Human cadaver study comparing 2 imaging modalities during iliosacral screw insertion; imaging randomized from side to side. SETTING: Bioskills laboratory in a medical school. PARTICIPANTS: Twenty-nine embalmed whole human cadavers without prior hip or pelvic surgery. INTERVENTION: Iliosacral screws were inserted into the S1 bodies using a percutaneous insertion technique. Screws were inserted on one side using StdFluoro, and on the other side, screws were placed using VirtualFluoro. MAIN OUTCOME MEASUREMENTS: Time necessary for imaging preparation, screw insertion, and actual fluoroscopy were recorded. Accuracy and safety of screw placement was assessed using computed tomography and an anatomic dissection of the pelvis. RESULTS: : Fifty-six of 58 iliosacral screws were placed within the desired bony corridor of the posterior pelvis. One screw placed using each method was inserted erroneously, but both were relatively minor deviations. There were no obvious injuries to major vessels or nerve roots. The total surgical time required for preparation of imaging and screw insertion averaged 7.3 minutes using StdFluoro and 6.7 minutes using VirtualFluoro (P = 0.4). Although the time necessary for screw insertion using VirtualFluoro averaged only 3.5 minutes, compared to 7.0 minutes for StdFluoro (P < 0.05), this time savings was offset by that required for application and calibration of tracking devices when using VirtualFluoro. The average fluoroscopy time using StdFluoro method was 26 seconds, whereas that for the VirtualFluoro was only 6 seconds (P < 0.01). CONCLUSIONS: Most of the percutaneous iliosacral screws were safely inserted using StdFluoro and VirtualFluoro, and total surgical times were similar using both methods. As VirtualFluoro continues to evolve, improved efficiency in operative times may be expected. Currently, the most beneficial aspect of using VirtualFluoro during the insertion of percutaneous iliosacral screws appears to be significantly decreased use of fluoroscopy when compared to StdFluoro.

Aged↗

Gadolinium-enhanced magnetic resonance fluoroscopy used as micturating cystourethrography: experiences in adult male patients.

RATIONALE AND OBJECTIVE: To approach the concept of magnetic resonance (MR) imaging-monitored micturating cystourethrography (MRMCU) by using gadolinium-enhanced real-time MR fluoroscopy. METHODS: MRMCU was performed in 21 male patients (27-76 years) subsequent to gadolinium excretory MR urography. Patients were examined in supine position at 1.5 T. For MR fluoroscopy of the urethra during micturition, we used a T1-weighted single-slice gradient-echo sequence with continuous radial k-space acquisition. Image reconstruction was obtained with the sliding-window technique reaching a frame rate of 25/s. The image plane was guided interactively through the urethra, the bladder and the ureters without stopping the scan. RESULTS: Two patients were unable to void in supine position. With MR fluoroscopy, the flow of gadolinium-enhanced urine through the urethra was visualized in 19 patients, in 14 of whom with complete demonstration of the urethral anatomy subdivided into 5 segments. Four urethral segments were identified in 1 patient, 3 segments in 2 patients, 2 segments in 3 patients, and 1 segment in 1 patient. MRMCU demonstrated changes in the urethral anatomy and the urine flow in 2 patients with a neobladder and in 1 patient with hypertrophy of the prostate. Subject to the limitation of antegrade gadolinium application, interactive MRMCU allowed to determine whether the ureters were enhanced by gadolinium or not. CONCLUSION: Gadolinium-enhanced MR fluoroscopy using radial k-space acquisition has achieved complete demonstration of the segmental anatomy of the urethra in 74% of the male adult patients who were able to accomplish micturition. Although MR fluoroscopy was able to visualize the gadolinium-enhanced ureters, the current data do not permit to conclude that MRMCU can demonstrate vesicoureteral reflux, especially in children.

Adult↗

Validation of a two- to three-dimensional registration algorithm for aligning preoperative CT images and intraoperative fluoroscopy images.

We present a validation of an intensity based two- to three-dimensional image registration algorithm. The algorithm can register a CT volume to a single-plane fluoroscopy image. Four routinely acquired clinical data sets from patients who underwent endovascular treatment for an abdominal aortic aneurysm were used. Each data set was comprised of two intraoperative fluoroscopy images and a preoperative CT image. Regions of interest (ROI) were drawn around each vertebra in the CT and fluoroscopy images. Each CT image ROI was individually registered to the corresponding ROI in the fluoroscopy images. A cross validation approach was used to obtain a measure of registration consistency. Spinal movement between the preoperative and intraoperative scene was accounted for by using two fluoroscopy images. The consistency and robustness of the algorithm when using two similarity measures, pattern intensity and gradient difference, was investigated. Both similarity measures produced similar results. The consistency values were rotational errors below 0.74 degree and in-plane translational errors below 0.90 mm. These errors approximately relate to a two-dimensional projection error of 1.3 mm. The failure rate was less than 8.3% for three of the four data sets. However, for one of the data sets a much larger failure rate (28.5%) occurred.

Algorithms↗

Pulsed fluoroscopy detectability from interspersed adaptive forced-choice measurements.

Using a new reference/test, adaptive forced-choice method, we investigated detectability of low contrast disks in simulated x-ray fluoroscopy image sequences. The method minimized effects of undesirable variables, such as changes in subject attention level by alternating conventional fluoroscopy (reference) and low acquisition rate fluoroscopy (test) presentations. To compare absolute target detectability and x-ray dose requirements of reference and test presentations, the contrast of the test presentation was set equal to that of the reference presentation, and the dose of the test presentation was adapted to give equivalent detectability of disk targets. Comparing pulsed fluoroscopy at 15 acq/s (pulsed-15) and 7.5 acq/s (pulsed-7.5) with conventional fluoroscopy at 30 acq/s (pulsed-30), dose savings were found in 22 of 24 experiments. When averaged over 3 disk sizes and 4 subjects, savings were 22% and 26% for pulsed-15 and pulsed-7.5, respectively. In most experiments, the subject was given an unlimited time to view presentations. With unlimited display times, subjects took slightly longer to respond for pulsed-15 or pulsed-7.5 than for pulsed-30. In other experiments, display times were limited. As the restricted display time increased, absolute target detectability increased while the x-ray dose for equivalent detectability was unchanged. The number of frames, N, in a repeating loop was also varied. Absolute detectability increased as N increased from 1 to 30 but changed little as more frames were added up to 150. The new experimental paradigm gives efficient, robust comparisons of image data and is applicable to a wide variety of medical image perception problems.

Adult↗

CT fluoroscopy-guided biopsy of the lung or upper abdomen with a breath-hold monitoring and feedback system: a prospective randomized controlled clinical trial.

PURPOSE: To prospectively determine the clinical effectiveness of a breath-hold monitoring and feedback system in computed tomographic (CT) fluoroscopy-guided biopsies in which respiratory motion is a problem. MATERIALS AND METHODS: Institutional review board approval and oral and written informed consent were obtained. This study was HIPAA compliant. A bellows-based system was used to monitor respiration and provide patient feedback. A randomized controlled clinical trial compared intermittent mode CT fluoroscopy-guided biopsies of the lung or upper abdomen performed with (n = 56) and without (n = 57) the bellows system. Inclusion criteria for 113 patients were lesions 6 cm or smaller in maximum dimension that were not affixed to the chest or abdominal wall. Primary outcome measurements were CT fluoroscopy exposure time and patient dose. Wilcoxon rank sum, chi(2), and Fisher exact tests were used for statistical analysis. RESULTS: Median CT fluoroscopy exposure time was 12.6 seconds (range, 2.4-44.4 seconds) for the bellows group and 18.0 seconds (range, 6.0-118.0 seconds) for the nonbellows group (P = .004). Patient dose was decreased in the bellows group (median dose, 29.5 mGy; range, 4.7-135.8 mGy) versus the nonbellows group (median, 41.3 mGy; range, 11.8-155.9 mGy) (P = .01). Lesions were accessed successfully with one needle puncture attempt in 43 of 56 patients (77%) in the bellows group and 30 of 57 patients (53%) in the nonbellows group (P = .007). Pneumothorax developed in 11 of 50 patients (22%) in the bellows group who underwent lung biopsy compared with 16 of 50 (32%) patients in the nonbellows group. CONCLUSION: A breath-hold monitoring and feedback system allows depiction of mobile target lesions throughout CT fluoroscopy-guided biopsy of the lung and upper abdomen.

Abdomen↗

Visibility of gallstone fragments at US and fluoroscopy: implications for monitoring gallstone lithotripsy.

To assess the value of ultrasound (US), fluoroscopy, and spot radiography in the detection, counting, and measurement of gallstone fragments during lithotripsy, in vitro visibility studies were conducted on fragments from 20 stones. Fluoroscopic visibility was evaluated during and after lithotripsy on 185 fragments placed in an anthropomorphic phantom. Three US experiments were performed on the fragments to study the visibility of fragments as a function of size, the accuracy of the count with large numbers of fragments, and the ability of observers to detect and count fragments larger than both 4 mm and 5 mm. With fluoroscopy, fragment detection rates ranged from 20% (fragments larger than 2.5 mm) to 80% (fragments larger than 4.5 mm). With US, all fragments larger than 1.5 mm were detected, and US was significantly better than fluoroscopy and spot radiography for detection of fragments 2.5 mm or smaller. US was also more accurate than fluoroscopy (11% vs 59% error) in the assessment of the number of fragments. When fragments larger than 4 mm or 5 mm were being counted with US, 92% of the fragments were visualized. The results suggest that US is more accurate for monitoring gallstone lithotripsy than fluoroscopy or spot radiography.

Cholelithiasis↗

Is fluoroscopy essential for retrieval of lower ureteric stones?

INTRODUCTION: The aim of this study was to assess the efficacy of ureteroscopy for lower ureteric stones without the use of fluoroscopy. PATIENTS AND METHODS: Between June 2001 and January 2005, a total of 110 patients with a mean age of 33.5 years (range 12-65) suffering from of lower ureteral calculi (below the upper margin of the sacroiliac joint) prospectively underwent ureteroscopic removal. Retrograde pyelography was avoided, and no safety guidewire was placed. Whenever required, the ureteric meatus was dilated with a ureteric balloon under direct vision. Double-J stent placement was done with the aid of ureteroscopy. A fluoroscope was kept standby. The patients had a postoperative X-ray of the kidney-ureter-bladder region to document the stone clearance. RESULTS: The mean stone size was 8.7 mm (range 6-15). Complete clearance without the use of fluoroscopy was achieved in 99 patients (94.2%). Fluoroscopy was required in 6 patients (4%) for calcified stricture (n = 1), duplex system (n = 1), narrow and tortuous meatus causing difficulty in passing the 5-Fr balloon dilator (n = 3), and confirmation of spontaneous passage of the stone (n = 1). Of the 13 patients who required balloon dilatation it was successfully achieved without fluoroscopy. Double-J stenting was done due to mucosal ulceration (n = 3), polypoid reaction (n = 2), and perforation (n = 1). All these patients had correct placement of the stent, as confirmed by X-ray of the kidney-ureter-bladder region postoperatively. CONCLUSIONS: To uphold the notion for radiation exposure to be as low as reasonably achievable, ureteroscopic stone retrieval can safely be done without the use of fluoroscopy in a significant number of patients.

Adolescent↗