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PubMed1989

Breast cancer after multiple chest fluoroscopies: second follow-up of Massachusetts women with tuberculosis.

A second follow-up was conducted of 1742 women with tuberculosis who were treated in one of two sanatoria in Massachusetts between 1930 and 1956. One hospital treated only children under the age of 17. Patient follow-up was extended from 1975 through 1980, and an additional 18 breast cancers were identified from hospital records, death certificates, and responses to a mailed questionnaire. Vital status was established for 97% of the subjects. Among 1044 women who were examined an average of 101 times with X-ray fluoroscopies during lung collapse therapy, 55 breast cancers were observed in contrast to 35.8 expected, based on incidence rates from the general population. No excess was found for 698 women treated by other means (19 observed versus 22.8 expected). Excess breast cancer risk did not appear until 15 years after initial exposure and was present at the end of 50 years of observation. Risk appeared to decrease with increasing age at exposure. Estimates of radiation dose to the breast for individuals (mean = 96 rad) were based on the most current information for the numbers of fluoroscopies, reconstruction of exposure conditions, and absorbed dose calculations. The relation between dose and breast cancer risk was consistent with linearity up to 400 rads (4 Gy). For 10-year survivors, the absolute excess risk was 5.5/1 million woman-year-rad, the excess relative risk per rad was 0.73%, and the relative risk at 100 rad was 1.7. These data indicate that a woman's lifetime risk of breast cancer is influenced by events occurring in early reproductive life, that low-dose fractionated exposures are as effective as single exposures of the same total dose in inducing breast cancer, and that risk of radiogenic breast cancer persists for many years, and perhaps for life.

Adolescent↗

PubMed1984

[Radiography or fluoroscopy. Considerations beyond radiation protection].

A comparison is made between taking radiographs versus fluoroscopy in veterinary medicine. In this evaluation three main features are of importance: financial restrictions, diagnostic quality of x-ray image, radiation protection or radiation hazards. All three aspects show unequivocally that radiography has to be preferred. Fluoroscopy should be the exception and should be used only for special examinations.

Animals↗

PubMed1983

Cardiac fluoroscopy.

The two basic radiologic approaches to heart disease are roentgenography and fluoroscopy. The purpose of this article is to examine the usefulness and limitations of cardiac fluoroscopy in order to put it into proper perspective.

Adipose Tissue↗

PubMed1983

Gastroesophageal reflux--reassessment of the value of fluoroscopy based on manometric evaluation of the lower esophageal segment.

The value of fluoroscopic gastroesophageal reflux examination by barium swallow was assessed in 51 symptomatic patients. Using electronic esophageal manometry, these patients were divided in groups with frank reflux, intermittent reflux, and symptoms of other etiology. Although a high incidence between presence of an hiatal hernia and manometric reflux (0.86) was apparent, fluoroscopy was only able to identify 33% of patients suffering from reflux disease diagnosed on clinical grounds and by electronic manometry. It is concluded that the fluoroscopic test is insufficient to separate patients with reflux disease from those with similar symptoms of other etiology which may be done reliably by esophageal manometry. The role of fluoroscopy is limited to the morphological evaluation of the gastroesophageal junction.

Adult↗

PubMed1981

[Coronary artery calcification fluoroscopy. A report on procedure of detection and clinical significance (author's transl)].

The methodology of cardiac fluoroscopy and the clinical significance of the coronary artery calcification are judged on the basis of a study on the group of 396 normal persons, 22.72% of whom resulted to suffer from it, while the report says that 46.80% of a group of 94 patients with coronary artery disease suffer from the same. In normal people the coronary artery calcification has practically the same frequency in both sexes and increases with the age, while in patients with coronary artery diseases there is a higher frequency in the fifth decade and in male sex. The discovery of calcification in all cases always shows an advanced coronary atherosclerosis. In the patients with clinical coronary artery diseases, there are also evidence of significative obstructive lesion. The fluoroscopy of the heart is the most powerful tool for the diagnosis of coronary artery calcification in vivo, it is easy to be used and gives diagnostic information of great value in the study of a coronary artery disease.

Adult↗

PubMed1995

A fluoroscopy credentialling programme for orthopaedic surgeons.

We have developed a teaching programme for non-radiologists who use fluoroscopy, which includes techniques for reducing the radiation received by the patient and the surgeon during orthopaedic procedures. The techniques resolve around the radiation protection concepts of time, distance and shielding. The programme has been very successful in reducing the total fluoroscopy times of orthopaedic surgeons; in our institute, durations have been reduced to about 10% of those before the training started. We review the aims and content of our programme.

Education, Medical, Continuing↗

PubMed1995

Lung cancer mortality between 1950 and 1987 after exposure to fractionated moderate-dose-rate ionizing radiation in the Canadian fluoroscopy cohort study and a comparison with lung cancer mortality in the Atomic Bomb survivors study.

Current lung cancer risk estimates after exposure to low-linear energy transfer radiation such as X rays are based on studies of people exposed to such radiation at high dose rates, for example the atomic bomb survivors. Radiobiology and animal experiments suggest that risks from exposure at low to moderate dose rates, for example medical diagnostic procedures, may be over-estimated by such risk models, but data for humans to examine this issue are limited. In this paper we report on lung cancer mortality between 1950 and 1987 in a cohort of 64,172 Canadian tuberculosis patients, of whom 39% were exposed to highly fractionated multiple chest fluoroscopies leading to a mean lung radiation dose of 1.02 Sv received at moderate dose rates. These data have been used to estimate the excess relative risk per sievert of lung cancer mortality, and this is compared directly to estimates derived from 75,991 atomic bomb survivors. Based on 1,178 lung cancer deaths in the fluoroscopy study, there was no evidence of any positive association between risk and dose, with the relative risk at 1 Sv being 1.00 (95% confidence interval 0.94, 1.07), which contrasts with that based on the atomic bomb survivors, 1.60 (1.27, 1.99). The difference in effect between the two studies almost certainly did not arise by chance (P = 0.0001). This study provides strong support from data for humans for a substantial fractionation/dose-rate effect for low-linear energy transfer radiation and lung cancer risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Percutaneous biliary stone removal under fluoroscopy.

BACKGROUND: Bile duct stone is a common biliary tract disease in Taiwan. Surgery and choledochoscopy are the current methods of treatment. This is a retrospective review of 65 cases who were admitted with postoperative biliary residual stones, or cholangitis secondary to the biliary stones. Percutaneous biliary stone removals under fluoroscopy were attempted. METHODS: Either a T-tube tract or percutaneous transhepatic cholangial drainage tract or both were used for stone removal. Angiographic superselective catheterization technique was applied for superselective cholangiography to identify the location of stones and to deliver basket and electrohydraulic lithotripsy probe to the site of the stones. Balloon dilation was applied for biliary stricture. RESULTS: Most of the cases needed multiple sessions (four, on an average) to remove all stones. There were 52% of the cases who needed balloon dilation for associated biliary strictures, and 7.7% of the cases had residual stones at the end of the procedure, because of technical difficulties. Chills and fever, pancreatitis, hepatic arterial injury and perforation of the common bile duct were procedure-related complications. In follow-up studies, 15% of the cases had recurrent biliary stones and 4.6% of the patients expired from malignant biliary tumors. CONCLUSIONS: Percutaneous biliary stone removal under fluoroscopy is beneficial for direct visualization of the location and number of the stones, and the architectural changes of the bile ducts. Superselective catheterization and balloon dilation were responsible for the high success rate (92.5%) here.

Adolescent↗

PubMed1994

[Initial cost-benefit analysis of chest fluoroscopy in synthetic clue investigation on tuberculosis].

Body surface exposure to X-ray radiation was measured in those with synthetic clue investigation on tuberculosis. The results showed body surface exposure in them appeared a logarithmic normal distribution with a geometric mean of 0.19 mC/kg and was higher than that with fluoroscopy in routine check-ups. The late effect of X-ray radiation showed 0.52 hours of an average life-span cut. But, based on prevalence, mortality and cure rate of chemotherapy for tuberculosis in Jiangsu Province, chest fluoroscopy in synthetic clue investigations brought an average prolongation of 45.8 hours per person in life-span of those X-rayed. Comparison of life-span showed synthetic clue investigation was an adequate method in active tuberculosis case-finding from the viewpoint of radiation protection.

Adolescent↗

PubMed1993

Esophageal dilation with polyvinyl bougies, using a marked guidewire without the aid of fluoroscopy: an update.

One hundred thirty-eight patients with esophageal stricture underwent polyvinyl bougie dilations whereby American Endoscopy dilators were passed over a marked guidewire that had been placed endoscopically. Fluoroscopy was not utilized during the dilations. The dilations were performed only after the guidewire was properly placed, with 60-cm markings at the incisors, which ensured that the tip of the guidewire was in the antrum. One hundred fourteen patients had benign strictures and 24 had malignant strictures. There were 197 sessions of dilations for a total of 748 individual dilations. In 97 of 138 patients, the guidewire was placed in the antrum under direct vision. The remaining 41 patients had significant esophageal stenosis which prevented passage of the endoscope into the stomach; therefore, the guidewire was placed by advancing it blindly through the stenosis. There were no procedure-related complications. During this period, eight patients were dilated without complications, using fluoroscopic placement of guidewire because endoscopic placement of the guidewire was not considered safe. We conclude that esophageal strictures can be safely dilated in most patients by means of the American Endoscopy dilator system and the marked guidewire without the aid of fluoroscopy.

Adult↗

PubMed1996

Breast cancer mortality between 1950 and 1987 after exposure to fractionated moderate-dose-rate ionizing radiation in the Canadian fluoroscopy cohort study and a comparison with breast cancer mortality in the atomic bomb survivors study.

The relationship between exposure to low-linear energy transfer ionizing radiation and subsequent breast cancer mortality risk is reported based on a further 7 years of follow-up in the Canadian fluoroscopy study. Amongst 31,917 women first treated for tuberculosis in a Canadian institution between 1930 and 1952, a total of 688 breast cancer deaths were observed between 1950 and 1987. There is a strong linear trend of increasing risk with increasing dose (P < 0.0001), with the excess relative risk per sievert decreasing with age at exposure (P = 0.0003). The excess relative risk is approximately constant between 5 and 39 years after exposure, with a suggestion of a decrease between 40 and 57 years after exposure, though this could be a chance effect (P = 0.22). Combined analyses of the Canadian fluoroscopy data and the data for the atomic bomb survivors with respect to breast cancer mortality are also reported. In general the two studies are reasonably consistent, the only distinct difference being the much greater excess relative risk per sievert amongst women exposed to very high doses in the province of Nova Scotia (P, heterogeneity <0.0001). Based on the combined data sets a simple relative risk (RR) model for the effect of a dose of D sieverts at age A years is developed: RR(D) = 1.0 + 0.52D exp[-0.10(A-15)]. This model fits the combined data well, and is used to predict excess lifetime risks of breast cancer mortality after radiation exposure from routine annual mammography.

Adolescent↗

PubMed1993

Digitally reconstructed fluoroscopy and other interactive volume visualizations in 3-D treatment planning.

PURPOSE: Add radiographic context to the beam's-eye-view used in 3-dimensional treatment planning. Improve methods for interactive visualization of anatomy and dose distributions. METHODS AND MATERIALS: Most 3-dimensional treatment planning systems feature a beam's-eye view that includes only graphical representations of patient anatomy. With input devices such as a mouse or trackball, the user interactively shapes the treatment field using the graphical models to provide geometric information. Radiographic context provides additional geometric information important for determining field shape. We have implemented digitally reconstructed fluoroscopy in the beam's-eye view by increasing the efficiency for computing digitally reconstructed radiographs. In addition we have improved algorithms for real-time surface and volume rendering for anatomy and doses using an experimental graphics supercomputer. RESULTS: Without radiographic context in the beam's-eye-view, field shapes were sometimes changed after simulation or portal images were obtained. Digitally reconstructed fluoroscopy has essentially eliminated these changes. Higher quality interactive three-dimensional displays improve the comprehension, confidence and efficiency of the user. Our improvements have already been implemented on one model of a new generation of commercial graphics workstations. CONCLUSION: Addition of radiographic context to the beam's-eye-view is recommended. Incorporation of higher quality interactive graphics is rapidly becoming practical and is encouraged.

Computer Simulation↗

PubMed2006

Magnetic resonance-fluoroscopy as long-term follow-up examination in patients with narrow gastric tube reconstruction after radical esophagectomy.

OBJECTIVE: To evaluate the functionality and morphology of neo-esophagus in subjects who underwent narrow gastric tube (NGT) reconstruction after total esophagectomy using magnetic resonance (MR)-fluoroscopy with Turbo-FLASH sequences acquired during positive oral contrast agent administration. METHODS AND MATERIALS: Ten patients, who underwent NGT reconstruction after total esophagectomy between 2002 and 2004, were studied using a 1.5 T magnet (Magnetom Avanto: Siemens, Erlangen, Germany, featuring total imaging matrix-TIM technology), equipped with surface phased-array and integrated spine coils. Imaging protocol included TRUFI and Turbo-FLASH sequences (TR=600 ms; TE=1.3 ms; Flip Angle 8 degrees ; Thickness 20 mm; FoV 350; Matrix 128 x 256; N. acquisition 120; TA=50 s) acquired on sagittal and axial planes to achieve motility evaluation during oral administration of positive contrast agent (yoghurt+Gd-DTPA 0.5M, 1:100 boluses). RESULTS: Good quality images were obtained in all patients, with adequate lumen contrast and a frame rate of 2.5 frames per second (fps). Three patients had completely re-established motility of NGT; six patients had mild to moderate alterations including raised transit time, reflux and contrast agent stasis; one patient had severe alterations with grossly dilated NGT, severe reflux and stasis. CONCLUSIONS: MR-fluoroscopy approach represents a promising radiation-free modality in the evaluation of functionality and morphology of NGT. Further investigation in the evaluation of post-surgery patients is necessary.

Adult↗

PubMed2005

The role of the MR-fluoroscopy in the diagnosis and staging of the pelvic organ prolapse.

INTRODUCTION: The aim of the study is to investigate the efficacy of the magnetic resonance fluoroscopy in the diagnosis and staging of the pelvic prolapse. MATERIALS AND METHODS: The study consisted of 46 patients who were known to have pelvic prolapses from their vaginal examination. Thirty women who underwent vaginal exam and shown not have pelvic prolapse were selected as a control group. Firstly, pelvic sagittal FSE T2 weighted images of all the women were acquired in 0.3 T open MR equipment than sagittal MR-fluoroscopic images using spoiled gradient echo sequences were obtained during pelvic strain. Physical examination and MR-fluoroscopic findings were compared. The relationship between the stages of prolapse established by both of the methods was evaluated statistically with Pearson's correlation analysis. RESULTS: Physical examination and MR findings were very concordant in the diagnosis of pelvic prolapse and statistical correlations in the stages of prolapse were established between both of the methods (P<0.01 for anterior and middle comportment, P<0.05 for posterior comportment). CONCLUSION: We conclude that MR-fluoroscopy is a non-invasive, easily applied, dynamic useful method without contrast agent in the diagnosis and staging of pelvic organ prolapse.

Adult↗

PubMed1998

Three-dimensional determination of femoral-tibial contact positions under in vivo conditions using fluoroscopy.

OBJECTIVE: A method has been developed to accurately measure three-dimensional (3-D) femoral-tibial contact positions of artificial knee implants in vivo from X-ray fluoroscopy images using interactive 3-D computer vision algorithms. DESIGN: A computerized graphical (CAD) model of an implant component is displayed as an overlay on the original X-ray image. An image matching algorithm matches the silhouette of the implant component against a library of images, in order to estimate the position and orientation (pose) of the component. The operator further adjusts the pose of the graphical model to improve the accuracy of the match. BACKGROUND: Previous methods for in vivo measurement of joint kinematics make only indirect measurements of joint kinematics, require invasive procedures such as markers or pins, or make simplifying assumptions about imaging geometry which can reduce the accuracy of the resulting measurements. METHODS: Fluoroscopic videos are taken of implanted knees in subjects performing weight-bearing motion. Images from the videos are digitized and stored on a computer workstation. Using computerized model matching, the relative pose of the two knee implant components can be determined in each image. The resulting information can be used to determine where the two components are contacting, the area of the contact region, liftoff angle, and other kinematic data. RESULTS: Accuracy tests done on simulated imagery and in vitro real imagery show that the pose estimation method is accurate to less than 0.5 mm of error (RMS) for translations parallel to the image plane. Orientation error is less than or equal to 0.35 degrees about any axis. Errors are larger for translations perpendicular to the image plane (up to 2.25 mm). In a clinical study, the method was used to measure in vivo contact points, and characterize the kinematic patterns of two different knee implant designs. CONCLUSIONS: The ability to accurately measure knee kinematics in vivo is critical for the understanding of the behavior of knee implant designs and the ultimate development of new, longer lasting implants. RELEVANCE: This work shows that it is possible to accurately measure the three-dimensional position and orientation (pose) of artificial knee implants in vivo from X-ray fluoroscopy images using interactive 3-D computer graphics. The method can be applied to any joint when accurate CAD models are available. The resulting data can be used to characterize the kinematics of current knee implant designs.

Journal Article↗

PubMedDate not supplied

Palliative esophageal stent placement using endoscopic guidance without fluoroscopy.

AIMS: Fluoroscopy is not available in every endoscopic unit. This situation leads to delays in treatment or to transfer of patients to other centres for stent insertion. We assessed safety and effectiveness of expandable esophageal metal stent placement under endoscopic control without fluoroscopy using a thin gastroscope. PATIENTS AND METHODS: From October 2002 to June 2004, thirty-three consecutive patients have been included for esophageal stent placement under endoscopic control alone with a nasogastroscope (5.9 mm). A proximal release covered stent (Ultraflex; Boston Scientific Microvasive) was used. Indications were malignant esophageal stricture (N = 26), malignant extrinsic compression (N = 2 ) and esophago-respiratory neoplastic fistulae (N = 5). RESULTS: Stent placement using endoscopic control alone was successful in 30/33 (90%) patients. Complications occurred in 11 patients. Early complications (<7 days) included one death from pulmonary embolism, severe retrosternal pain needing transient morphinic treatment (N = 2) and GERD despite antisecretory therapy (N = 1). Late complications included: food impaction (N = 1), tumour overgrowth-related obstruction of the stent (N = 5) and one late esophago-respiratory fistula at 4 months at the proximal end of the stent. Relief of dysphagia was obtained for all patients at 48 hours and dysphagia score decreased from 3.1 before stent to 1.2 at 1 month (P < 0.05). CONCLUSION: Expandable esophageal stents can be accurately and safely placed using endoscopy with a thin gastrosocope. This method obviates the requirement of fluoroscopic access, lacking in many centres, and avoids exposure to X-ray.

Aged↗

PubMed2002

Fluoroscopy-guided sacroiliac joint injections with phenol ablation for persistent sacroiliitis: a case series.

In this article we are reporting on the use of fluoroscopy-guided 6% Phenol injections for the ablation of the sacroiliac joints (SIJs), utilizing retrospective review of case reports. We reviewed 10 patients (7 male and 3 female) who have known sacroiliitis proven by fluoroscopically guided sacroiliac joint (SIJ) injection (age ranged from 25 to 78). They all had 2 to 4 weeks of relief after the injections utilizing Bupivacaine 0.5% and 80 mg of depomedrol. They all had repeat fluoroscopy-guided injections of the SIJs with neurolysis of either a unilateral SIJ or bilateral SIJs using 6% Phenol. Phenol 6% with saline 2.5 cc per joint was injected; the needle was cleared with local anesthetic before removing it from the joint. Twenty percent of the patients had a greater than 70% improvement with an average duration of 24 weeks. Sixty percent of the patients had a 50% to 70% improvement with an average duration of 20 weeks. Ten percent had a 20% to 50% improvement with a total duration of 12 1/2 weeks. Ten percent had a less than 20% improvement. With intra-articular injections of phenol for the ablation of the SIJs, we have found a significant improvement in pain relief accompanied by prolonged duration of relief.

Journal Article↗

PubMed1999

Digital radiology using active matrix readout: amplified pixel detector array for fluoroscopy.

Active matrix array technology has made possible the concept of flat panel imaging systems for radiography. In the conventional approach a thin-film circuit built on glass contains the necessary switching components (thin-film transistors or TFTs) to readout an image formed in either a phosphor or photoconductor layer. Extension of this concept to real time imaging--fluoroscopy--has had problems due to the very low noise required. A new design strategy for fluoroscopic active matrix flat panel detectors has therefore been investigated theoretically. In this approach, the active matrix has integrated thin-film amplifiers and readout electronics at each pixel and is called the amplified pixel detector array (APDA). Each amplified pixel consists of three thin-film transistors: an amplifier, a readout, and a reset TFT. The performance of the APDA approach compared to the conventional active matrix was investigated for two semiconductors commonly used to construct active matrix arrays--hydrogenated amorphous silicon and polycrystalline silicon. The results showed that with amplification close to the pixel, the noise from the external charge preamplifiers becomes insignificant. The thermal and flicker noise of the readout and the amplifying TFTs at the pixel become the dominant sources of noise. The magnitude of these noise sources is strongly dependent on the TFT geometry and its fabrication process. Both of these could be optimized to make the APDA active matrix operate at lower noise levels than is possible with the conventional approach. However, the APDA cannot be made to operate ideally (i.e., have noise limited only by the amount of radiation used) at the lowest exposure rate required in medical fluoroscopy.

Models, Theoretical↗