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Capitate-lunate instability: recognition by manipulation under fluoroscopy.

Videotape fluoroscopy was used to diagnose a previously undescribed carpal dissociation, the capitate lunate instability pattern. In eight patients with midcarpal pain and clicking, the examiner simultaneously applied pressure to the scaphoid tuberosity while applying longitudinal traction and flexion to the wrist under fluoroscopic control. This maneuver revealed dorsal subluxation of the proximal carpal row and capitate lunate subluxation in each of the eight patients. Plain radiography and arthrography were not helpful in the diagnosis. All eight cases were managed conservatively. Videotape fluoroscopy is the best radiologic method of diagnosing capitate-lunate instability.

Adolescent↗

Feasibility of instructing radiology technologists in the performance of gastrointestinal fluoroscopy.

OBJECTIVE: We sought to determine if dedicated gastrointestinal technologists could be trained to properly perform esophagography and double-contrast barium enema examinations. SUBJECTS AND METHODS: Ninety-four patients undergoing double-contrast barium enema examinations and 123 patients undergoing esophagographic examinations were included in the study. The study was conducted over a 4-month period, with examinations performed by eight gastrointestinal technologists, 10 radiology residents, and four staff radiologists. Four random lists were generated for each set of examinations. Each staff gastrointestinal radiologist, who was unaware of who had performed the examination, independently scored the representative radiographs. RESULTS: For the double-contrast barium enema examinations, no statistically significant differences were found between the technologists and residents for amount of barium used, degree of distention, cecal opacification, and quality of spot radiographs. The technologist-performed examinations had a statistically significant lower mean fluoroscopy time (3.2 min, compared with 4.0 min for staff radiologists and 5.7 min for residents). For the esophagrams, no statistically significant differences between technologists and residents were found for single-contrast esophagrams; radiographs of the gastric cardia; assessment of motility, reflux, and transit of a solid bolus; and fluoroscopy time. Double-contrast esophagrams obtained by technologists received a better mean score than did those of the residents. CONCLUSION: Radiology technologists can be trained to perform high-quality esophagography and double-contrast barium enema examinations without an unacceptably high radiation dose.

Adult↗

Percutaneous acetic acid injection for hepatocellular carcinoma: using CT fluoroscopy to evaluate distribution of acetic acid mixed with an iodinated contrast agent.

OBJECTIVE: The purpose of our study is to evaluate the distribution of acetic acid mixed with iodinated contrast agent during percutaneous acetic acid injection on CT fluoroscopy for hepatocellular carcinoma. CONCLUSION: Monitoring acetic acid distribution on CT fluoroscopy can detect extratumoral diffusion and may optimize the distribution of acetic acid in hepatocellular carcinoma.

Acetic Acid↗

Combining fine-needle aspiration and core biopsy under CT fluoroscopy guidance: a better way to treat patients with lung nodules?

OBJECTIVE: The goal of our study was to evaluate the efficacy of the combined use of fine-needle aspiration and tissue core biopsy under real-time CT fluoroscopy guidance. SUBJECTS AND METHODS: One hundred thirty-eight percutaneous needle lung biopsy samples were obtained by two methods. The samples obtained by tissue fine-needle aspiration underwent cytologic evaluation, and those obtained by core biopsy using an automated cutting needle underwent histologic evaluation. The final diagnosis was confirmed by independent surgical pathologic findings, independent culture results, or clinical follow-up. RESULTS: Rates of adequate specimens obtained and of precise diagnosis by combined use of fine-needle aspiration and core biopsy were 97.1% (134/138) and 94.2% (130/138) evaluated lung lesions, respectively, whereas those rates were 84.8% (117/138) and 79.7% (110/138) by fine-needle aspiration alone and 91.3% (126/138) and 89.1% (123/138) by core biopsy alone, respectively. Precise diagnosis was achieved by the combined use of the techniques in 30 (93.8%) of 32 lesions ranging from 3 to 10 mm in diameter, 42 (93.3%) of 45 lesions ranging from 11 to 20 mm, 43 (93.5%) of 46 lesions ranging from 21 to 30 mm, and 100% of 15 lesions ranging from 31 to 100 mm. In 89 of 90 lesions shown to be malignant by CT-guided lung biopsy and 30 of 44 shown to be benign, specific cell types could be proven from specimens obtained by the combined use of the two different types of needle biopsy. CONCLUSION: The combined use of fine-needle aspiration and core biopsy improves the diagnostic ability of CT fluoroscopy-guided lung biopsy, even in small lesions.

Adolescent↗

Cervical pedicle screw fixation in 100 cases of unstable cervical injuries: pedicle axis views obtained using fluoroscopy.

OBJECT: The authors conducted a study to introduce the imaging technique in which pedicle axis views are obtained using fluoroscopy to match the screw entry point with pedicle orientation and to report the clinical results and safety of cervical pedicle screw fixation (PSF) in patients treated for unstable cervical injuries. METHODS: One hundred consecutive patients with unstable cervical injuries underwent PSF in which the authors used fluoroscopic imaging to acquire pedicle axis views. There were 87 men and 13 women whose mean age was 42.5 years. The accuracy of PS placement was examined postoperatively using axial computed tomography (CT) and oblique radiography. Screw malpositioning was classified either as screw exposure (< 50% of the screw outside the pedicle) or pedicle perforation (> 50% of the screw outside the pedicle boundaries). The mean operative time was 97.6 minutes, and the mean estimated blood loss was 221 ml. Local vertebral alignment around the injured segment measured 6.0 degrees of kyphosis preoperatively and 6.7 degrees of lordosis postoperatively. Solid posterior bone fusion was achieved in all but three patients who died shortly after surgery. There was no secondary dislodgment of instrumentation in 95% of these 97 cases. Of the 419 cervical PSs, 43 (10.3%) were of the screw-exposure type and 17 (4.0%) of the pedicle-perforation type. There were two surgery-related complications: one penetration of a probe into the vertebral artery and one radiculopathy. There were six postoperative complications: two cases of instrumentation failure associated with loss of correction, three cases of correction loss (> 10 degrees), and one case of deep wound infection. CONCLUSIONS: Solid posterior fusion without secondary dislodgment of hardware was demonstrated in 95% of the cases. The incidence of complications associated with cervical PSF was not high. Postoperative CT scanning showed that 17 (4.0%) of 419 screws perforated the pedicle. It appears that fluoroscopy performed using pedicle axis views improves the accuracy and safety of cervical PS insertion.

Adolescent↗

Emergency ventricular pacing using a J-electrode catheter without fluoroscopy.

The initiation of emergency ventricular pacing may be delayed by a lack of facilities for immediate fluoroscopy or staff members who are skilled in positioning a transvenous electrode catheter. Techniques have been developed to overcome these problems but have been unreliable, expensive and/or uncomfortable for patients. In each of 20 consecutive haemodynamically unstable patients (13 patients with asystole or high-grade atrioventricular block and seven patients with ventricular tachycardia), an attempt was made to pace the ventricle with a Cordis 5-FG (1.67-mm) "atrial J"-electrode catheter, which was inserted transvenously without fluoroscopic guidance. Pacing was initiated successfully in 19 cases within 40 seconds to 30 minutes (median, two minutes) of skin puncture, and in 16 cases within three minutes. Fifteen procedures were performed by operators with experience of less than 10 previous pacing catheter insertions. This study demonstrates that emergency transvenous ventricular pacing can be initiated rapidly and reliably by means of a catheter with a "J" configuration, which is inserted without the use of fluoroscopy. The method can be employed successfully by operators with little experience in pacing techniques. Standard inexpensive equipment is used; the technique is safe and well-tolerated by patients.

Adult↗

Fluoroscopy of prosthetic heart valves: does it have a place in the echocardiography era?

Fluoroscopy is the best method for delineation of the radio-opaque elements of prosthetic heart valves. It is the modality of choice for the validation and quantification of leaflet motion abnormalities, and for the identification of structural valve dysfunction. Normal values are shown. Echocardiography and fluoroscopy may be seen as complementary diagnostic techniques and, when used appropriately, may help to evaluate prosthetic valve function, integrity and associated complications.

Echocardiography↗

High-dose fluoroscopy: the administrator's responsibilities.

During the past 15 years, developments in x-ray technologies have substantially improved the ability of practitioners to treat patients using fluoroscopically guided interventional techniques. Many of these procedures require a greater use of fluoroscopy and serial imaging (cine). This has increased the potential for radiation-induced dermatitis, epilation and severe radiation-induced burns to patients. Radiology administrators must realize that these high-dose procedures increase the risk for radiation injury and radiation-induced cancer in personnel as well as in patients. This article discusses particular clinical cases and describes positive, pro-active steps that practitioners and administrators can take to help prevent such injuries in their facilities. Unfortunately, with the exception of radiologists, a large proportion of physicians who use fluoroscopy have effectively no training or credentials in management of radiation or the biological effects associated with its use. In 1994, an FDA advisory warned that training of physicians for modern-day use of the fluoroscope was for the most part insufficient and needed to be expanded. Many prominent medical organizations such as the American College of Cardiology (14) and the American Heart Association (15) have published strongly worded position papers agreeing that there is an urgent need for such training. The consensus is that "rubber-stamp" privileges (16,17) to perform fluoroscopic procedures should no longer be granted. At present, the JCAHO is considering the implementation of a statement regarding JCAHO standards and privileges for practitioners to use fluoroscopic x-ray equipment. Whether or not the JCAHO becomes involved, it is becoming increasingly clear that all practitioners who use fluoroscopic radiation should be required to complete focused training in radiation physics, radiation biology and radiation safety. Training should include the pertinent aspects of radiation management in the clinical setting so that these physicians will be able to acceptably control risks to patients and personnel. The task of securing these materials and lecturers and documenting everything may fall on the shoulders of the radiology administrator or radiation safety staff. Completion of an approved educational program (with appropriate testing) provides the evidence needed by the facility to approve the practitioner's qualifications. In summary, it will take a concerted effort on the part of professional medical organizations and regulatory agencies to insure that the wealth of preventative information now available is disseminated to and put to use by these physicians who may fail to fully appreciate the potential for imparting serious injury to their patients. Even one radiation injury caused by lack of education is unacceptable.

Burns↗

Radiation safety in fluoroscopy.

Fluoroscopy is an important diagnostic and interventional imaging tool that enables clinicians to view dynamic, real-time images of anatomy and function unmatched by other imaging techniques. However, operators must take into account many factors that impact the amount of radiation delivered, particularly over the course of a lengthy interventional procedure. After completing this review, readers will: Understand basic concepts of radiobiology and fluoroscopy systems. Know the typical doses and dose calculations for patients and fluoroscopic personnel. Recognize the pathology of biological effects and common radiation-induced skin injuries. Understand fluoroscopic technique factors to reduce patient exposure. Know the basic methods for controlling occupational exposure for fluoroscopic personnel.

Dose-Response Relationship, Radiation↗

Measurement of HVL on fluoroscopy units.

The total filtration of a fluoroscopy x-ray tube assembly may be deduced from the half value layer (HVL) of the x-ray beam at a specified tube voltage using published data tables. The HVL is usually measured by placing increasing thicknesses of Al plates between the focus and a dosimeter, and measuring the output while keeping the kV constant. However, on many of the newer fluoroscopy units, it is not possible to set the tube potential manually. This can create difficulties when measuring the HVL since the increasing thicknesses of aluminum trigger the automatic brightness control to adjust the kV and mA automatically, thus altering the tube output and HVL. This communication describes a simple but effective method to measure the amount of filtration on such units, which has the advantage of not requiring any extra equipment.

Calibration↗

Increased radiation dose by automatic exposure control system during fluoroscopy and angiography of pelvis due to contrast material in the bladder: experimental study.

PURPOSE: To evaluate the increase of radiation dose caused by contrast material excreted in the bladder during vascular interventional procedures of the pelvis. MATERIALS AND METHODS: A latex balloon filled with diluted contrast material, simulating the bladder, was placed in a water phantom. Entrance dose rates were measured under various conditions with and without the balloon. In animal experiments, skin doses during fluoroscopy and angiographic image acquisitions were measured at the pelvis of a swine before and after the contrast was excreted in the bladder. RESULTS: In phantom experiments, fluoroscopic dose rates increased 1.3- to 3.9-fold when the contrast-filled balloon was placed at the periphery of the phantom. The dose rates increased 3.0- to 4.0-fold when the balloon was placed at the center. In the animal experiment, dose rates increased 1.4- to 2.0-fold when the bladder was filled with contrast material. Skin doses during 10-second angiographic image acquisition also increased 1.1- to 2.3-fold when the bladder was filled with contrast. CONCLUSION: When the bladder is filled with excreted contrast material, skin doses delivered by fluoroscopy and angiography will increase. Removal of urine is recommended during vascular interventional procedures of the pelvis.

Angiography↗

[Bronchoscopic lung biopsy with fluoroscopy to study 164 localized pulmonary lesions].

OBJECTIVE: To assess the usefulness of bronchoscopic lung biopsy (BLB) in the diagnosis of localized pulmonary lesions. METHODS: A prospective, descriptive study of consecutive patients with a suspected neoplastic nodule, mass, or infiltrate with nonspecific bronchoscopic findings after performing BLB with fluoroscopy. The lesions, clinical and patient characteristics, and outcomes were evaluated. RESULTS: One hundred sixty-four patients with a mean (SD) age of 65 +/- 12 years and a total of 156 masses or nodules and 8 infiltrates (144 neoplasms and 20 nonneoplastic lesions) participated in the study. On average, the lesion was 4.3 +/- 2 cm in diameter and 6 +/- 2 BLBs were performed on each patient, with a rate of serious complications of less than 1%. BLB was diagnostic in 113 cases (69% of the neoplasms and 70% of the nonneoplastic). In cases diagnosed by BLB, the lesions were larger (4.6 +/- 2 cm), more samples were obtained (6 +/- 2 biopsies), nondiagnostic endoscopic alterations were found (30%), and the bronchus sign was present (22%). Moreover, bronchoscopy was better tolerated by those patients. CONCLUSIONS: BLB with fluoroscopy increased the diagnostic yield of bronchoscopy for localized lesions with nonspecific findings, regardless of etiology. Larger neoplasms, the bronchus sign, good tolerance, and more tissue samples increased the number of diagnoses, with few complications.

Aged↗

Zero-dose fluoroscopy-based close reduction and osteosynthesis of diaphyseal fracture of femurs.

This paper presents a novel technique to create a computerized fluoroscopy with zero-dose image updates for computer-assisted fluoroscopy-based close reduction and osteosynthesis of diaphyseal fracture of femurs. With the novel technique, repositioning of bone fragments during close fracture reduction will lead to image updates in each acquired imaging plane, which is equivalent to using several fluoroscopes simultaneously from different directions but without any X-ray radiation. Its application facilitates the whole fracture reduction and osteosynthesis procedure when combining with the existing leg length and antetorsion restoration methods and may result in great reduction of the X-ray radiation to the patient and to the surgical team. In this paper, we present the approach for achieving such a technique and the experimental results with plastic bones.

Algorithms↗

Clinical background and its relation to results of percutaneous needle biopsy of suspected bone metastasis under guidance with CT fluoroscopy.

PURPOSE: To investigate the clinical background of needle biopsy of suspected bone metastasis under guidance with CT fluoroscopy. PATIENTS AND METHODS: During a 3-year period (from April 2000 to March 2003), 103 needle biopsies on 101 lesions of 90 patients were performed for pathological evaluation of suspected bone metastasis. The clinical course of these patients prior to biopsy and its relation to the biopsy results were retrospectively reviewed. RESULTS: Sixty-two patients (69% of total cases) were referred for biopsy from orthopedic surgeons, and 51 of these patients consulted orthopedic surgeons on the initial presentation. Malignancy was pathologically proved in 47 (76%) of the 62 orthopedic patients, and in 19 (68%) of the 28 patients referred from other clinicians. Thirteen (21%) of the orthopedic patients had a history of malignancy, while 22 (78%) of the non-orthopedic patients were cancer patients. Metastasis was pathologically proved in 23 (66%) of the 35 patients with a history of malignancy, while malignancy was pathologically proved in 43 (78%) of the 55 patients without known malignancy. Diagnostic accuracy of the needle bone biopsy was 96%, and its complication rate was 0.7%. CONCLUSION: In the era of CT fluoroscopy, needle biopsy for suspected bone metastasis was most frequently requested for the patients who consulted orthopedic surgeons for the occurrence of local bone pain as the initial symptom of unknown malignancy. Frequency of malignancy proved by the biopsy in those patients was as high as that in the cancer patients referred from other clinicians.

Adolescent↗

Use of fluoroscopy to evaluate iliac screw position.

Iliac screw fixation is often used for long fusions to the sacropelvis. Maximum iliac screw purchase is obtained both by placing the screws within 1.5 cm of the greater sciatic notch and by extending them anterior to the axis of rotation in flexion-extension. Screw insertion is "blinded" or dependent on tactile feedback, and hence extreme care is necessary to avoid incorrect placement and damage to vital neurovascular structures in the pelvis and sciatic notch. Long screws may violate the hip joint while medial placement may injure the lumbosacral plexus and the nearby vessels. To explore the best intraoperative fluoroscopic method of determining optimal iliac screw placement, we used a synthetic pelvis model to investigate screw placement conditions: (1) optimal anatomic placement, (2) violation of the sciatic notch, (3) hip joint violation, (4) medial wall violation, and (5) lateral wall violation. Each condition was examined utilizing fluoroscopy with posteroanterior, inlet, outlet, lateral, iliac oblique, and obturator oblique Judet views to simulate operative conditions. These views were obtained to evaluate critical malposition of iliac screws. We found that, for a sciatic notch violation, the obturator oblique view best demonstrated the cortical breech, while for a hip joint violation, the inlet and outlet views were best. For a medial wall violation, the iliac oblique view best showed the violation. For a lateral wall violation, we were unable to demonstrate the cortical breech using these fluoroscopic views. Fluoroscopy is an effective method to determine sciatic notch, hip joint, and medial wall violations after iliac screw placement; however, it is not effective in identifying a lateral wall violation.

Bone Screws↗

Computer-assisted, fluoroscopy-based ventral spondylodesis of thoracolumbar fractures.

OBJECTIVE: To design and evaluate a novel computer-assisted, fluoroscopy-based planning and navigation system for minimally invasive ventral spondylodesis of thoracolumbar fractures. MATERIALS AND METHODS: Instruments and an image intensifier are tracked with the SurgiGATE navigation system (Praxim-Medivision). Two fluoroscopic images, one acquired from anterior-posterior (AP) direction and the other from lateral-medial (LM) direction, are used for the complete procedure of planning and navigation. Both of them are calibrated with a custom-made software to recover their projection geometry and to co-register them to a common patient reference coordinate system, which is established by attaching an opto-electronically trackable dynamic reference base (DRB) on the operated vertebra. A bi-planar landmark reconstruction method is used to acquire deep-seated anatomical landmarks such that an intraoperative planning of graft bed can be interactively done. Finally, surgical actions such as the placement of the stabilization devices and the formation of the graft bed using a custom-made chisel are visualized to the surgeon by superimposing virtual instrument representations onto the acquired images. The distance between the instrument tip and each wall of the planned graft bed are calculated on the fly and presented to the surgeon so that the surgeon could formalize the graft bed exactly according to his/her plan. RESULTS: Laboratory studies on phantom and on 27 plastic vertebras demonstrate the high precision of the proposed navigation system. Compared with CT-based measurement, a mean error of 1.0 mm with a standard deviation of 0.1 mm was found. CONCLUSIONS: The proposed computer assisted, fluoroscopy-based planning and navigation system promises to increase the accuracy and reliability of minimally invasive ventral spondylodesis of thoracolumbar fractures.

Algorithms↗

Percutaneous radio-frequency mandibular nerve rhizotomy guided by CT fluoroscopy.

We describe a new method for radio-frequency mandibular nerve rhizotomy under CT fluoroscopy. A patient with cancer had severe intractable and drug-resistant pain in his left mandibular region. Because he had an anatomic deformity due to cancer invasion and radiation therapy, we planned a mandibular nerve rhizotomy under CT fluoroscopic imaging. The needle was advanced to the mandibular nerve just caudal to the foramen ovale under real-time CT fluoroscopy, avoiding the cancer region. Pain scores of the patient were reduced after the nerve rhizotomy, without any complications.

Catheter Ablation↗

Frequent chest X-ray fluoroscopy and breast cancer incidence among tuberculosis patients in Massachusetts.

The incidence of breast cancer was determined in 4940 women treated for tuberculosis between 1925 and 1954 in Massachusetts. Among 2573 women examined by X-ray fluoroscopy an average of 88 times during lung collapse therapy and followed for an average of 30 years, 147 breast cancers occurred in contrast to 113.6 expected [observed/expected (O/E) = 1.29; 95% confidence interval (CI) = 1.1-1.5]. No excess of breast cancer was seen among 2367 women treated by other means: 87 observed versus 100.9 expected. Increased rates for breast cancer were not apparent until about 10 to 15 years after the initial fluoroscopy examination. Excess risk then remained high throughout all intervals of follow-up, up to 50 years after first exposure. Age at exposure strongly influenced the risk of radiation-induced breast cancer with young women being at highest risk and those over age 40 being at lowest risk [relative risk (RR) = 1.06]. Mean radiation dose to the breast was estimated to be 79 cGy, and there was strong evidence for a linear relationship between dose and breast cancer risk. Allowing for a 10-year minimum latent period, the relative risk at 1 Gy was estimated as 1.61 and the absolute excess as 10.7 per 10(4) woman-years per gray. When compared to other studies, our data suggest that the breast is one of the most sensitive tissues to the carcinogenic force of radiation, that fractionated exposures are similar to single exposures of the same total dose in their ability to induce breast cancer, that risk remains high for many years after exposure, and that young women are especially vulnerable to radiation injury.

Breast Neoplasms↗