Use Of Digital Radiography Research Articles

The feasibility of low-dose CT for pulmonary metastasis in patients with primary gynecologic malignancy

Purpose To assess the feasibility of low-dose CT (LDCT) in the detection of pulmonary metastases in patients with primary gynecologic malignancies and also to compare the performance of chest digital radiography (DR) and LDCT for their delectability of pulmonary metastases, with use of standard-dose CT (SDCT) as the reference standard. Materials and methods Thirty female patients with primary gynecologic malignancies (age range, 20–76 years; mean age, 50 years) underwent DR, noncontrast LDCT and contrast-enhanced SDCT, which were performed within an interval of 2 weeks. We used lung nodule, mediastinal lymphadenopathy (>10 mm in the short axis) and pleural changes (including effusion, irregular thickening, or nodularity) as the cardinal imaging findings of lung metastases. A five-point scoring system was designed to indicate the probability of lung metastasis from primary gynecologic malignancies. The five-point scores of DR, LDCT, and SDCT were analyzed by receiver operating characteristic (ROC) curve. Results SDCT probability scores of +2 and −2 were set to indicate true positive and true negative for pulmonary nodule, mediastinal lymphadenopathy, and pleural effusion, respectively. All the areas under the ROC curve of LDCT appeared to be larger than those of DR{pulmonary nodule: 0.96 [95% confidence interval (CI): 0.92–1.01] vs. 0.74 [95% CI: 0.57–0.91], 0.82 [95% CI: 0.70–0.95] vs. 0.61 [95% CI: 0.50–0.77]; mediastinal lymphadenopathy: 0.98 [95% CI: 0.93–1.03] vs. 0.90 [95% CI: 0.79–1.01], 0.94 [95% CI: 0.82–1.06] vs. 0.66 [95% CI: 0.44–0.88]; and pleural effusion: 0.98 [95% CI: 0.93–1.03] vs. 0.56 [95% CI: 0.29–0.82], 0.90 [95% CI: 0.74–1.05] vs. 0.46 [95% CI: 0.23–0.68]}. Conclusion The performance of LDCT were comparable to those of SDCT and superior to those of DR for detection of pulmonary nodule, mediastinal lymphadenopathy, and pleural effusion. By using LDCT, there was no need of intravenous contrast injection and less radiation exposure. We propose a protocol including standard-dose abdominal CT and low-dose chest CT for the initial and follow-up stagings of primary gynecologic malignancy. The use of chest DR is unnecessary.

Differential diagnosis of rheumatic diseases using conventional radiography

The approach to the differential diagnosis of rheumatic diseases using conventional radiography is systematic and module-oriented, which, with respect to future developments, forms the basis for computer-assisted diagnosis (CAD). The indications follow consensus-based referral criteria and attempts should be made to raise the evidence level of the recommendations. Investigation techniques have been improved in the last few years with the use of digital radiography. New imaging technologies may be available in the future that will achieve at least the same quality of images, while exposing patients to a significantly lower radiation dose. The interpretation of radiographical signs could be enhanced through a correlation with other imaging modalities. Computer-assisted techniques with image processing tools for automated measurements, lesion detection and in the form of expert systems are under development. With conventional radiography embedded in CAD systems, promising options will be available to enhance the differential diagnosis of rheumatic diseases.

Storage phosphor plates: how durable are they as a digital dental radiographic system?

Background. The exclusive use of digital radiography based on a storage phosphor system at the Univeristy of Missouri–Kansas City School of Dentistry raised some questions about the durability of the storage phosphor plates (SPPs). The digital images acquired from SPPs that have been repeatedly used seem to demonstrate a lower quality owing to the appearance of scratches. These scratches sometimes render the image completely undiagnostic and may lead to a “remake” of the radiograph. Our observations indicated that the durability of this imaging system may be limited, despite the manufacturer's claim that the SPPs can be used indefinitely.

Experience of Norwegian general dental practitioners with solid state and storage phosphor detectors.

To evaluate the opinions of Norwegian dental practitioners regarding the use of solid state sensor and storage phosphor (SP) detectors for intra-oral radiography. A questionnaire received from 2199 dentists 309 (219 male, 86 female, four unknown) confirmed the use of digital radiography in their practices. Sixty-one per cent of dentists used a SP and 35% a sensor system; four (1.3%) used both. Approximately 50% of dentists had experienced technical problems and 33% had needed repairs. Almost all dentists stored their images on the hard disk (>97%) and 81% made a daily back-up. More sensor than SP users found difficulty with the positioning holder. Two-thirds of dentists reported digital image quality was the same or better than film. More Digora (Soredex, Helsinki, Finland) users reported better image quality than Denoptix (Gendex, Milan, Italy) or Digident (Digident, Nesher, Israel) users. Mean reduction in exposure time was 55% (range 2-90%), although 17 dentists stated that no reduction was achieved. Approximately half of the sensor users also used film and 38% of the SP users. Film was used more often for bitewing examination by the sensor users (27%) than by the SP users (4%). Mean time saved by the sensor users was 36 min/day (range 10-120) and by the SP users 25 min/day (range 5-120). The majority of dentists felt that digital image quality was the same or better than film and exposure and examination times were reduced. However, technical problems and repairs were common.

Contemporary pediatric thoracic imaging.

children, and its high efficacy and clinical use in the pediatric intensive care setting have been recently confirmed [3]. Unfortunately, chest radiography is also one of the most challenging examinations to perform because of the wide range of tissue densities present in the thorax (especially considering the wide variety of thoracic sizes in pediatric patients), the inherently low-contrast structures of children, and the need to minimize exposure to ionizing radiation. These difficulties imaging children are further complicated by the requirement that images be acquired at peak inspiration and with minimum patient motion, a daunting task when imaging young or uncooperative children. The use of digital radiography is increasing, but the technical basis of the systems may be unfamiliar. In this section, we discuss and illustrate the most common commercial digital systems in addition to conventional radiography suitable for pediatric chest radiography. Conventional Radiography

Monte Carlo simulations of x-ray induced recombination in amorphous selenium

The photoconductor amorphous selenium (a-Se) has been used inmedical imaging since the 1950s, and is currently under studyfor use in digital radiography. The quantity of interest forradiographic applications is the energy required to create a detectable electron-hole pair, W±, which is governed by therecombination of electron-hole pairs. Both geminate and columnarrecombination theories have been invoked to describerecombination in a-Se, without success. In this work, we develop aMonte Carlo code which follows individual collisions along thex-ray/electron track structure in order to determine the initialpositions of the electron-hole pairs within a-Se. Wesubsequently simulate the transport of the pairs within anelectric field to calculate the amount of recombination. We usethese simulations to calculate W± as a function ofapplied electric field and incident x-ray energy. We findexcellent agreement between our simulations and experimentalresults. This indicates that the recombination occurs not onlybetween geminate pairs but also between other pairs created alongthe track. This inter-track recombination leads to an energydependent recombination probability which could not be explainedwith previous recombination theories.

1.心臓カテーテル検査領域におけるディジタル画像の有用性(ディジタル画像の有用性)

1.心臓カテーテル検査領域におけるディジタル画像の有用性(ディジタル画像の有用性)

3.消化管撮影領域におけるディジタル画像の有用性(ディジタル画像の有用性)

3.消化管撮影領域におけるディジタル画像の有用性(ディジタル画像の有用性)

2.血管撮影検査におけるディジタル画像の有用性(ディジタル画像の有用性)

2.血管撮影検査におけるディジタル画像の有用性(ディジタル画像の有用性)

座長集約(ディジタル画像の有用性)

座長集約(ディジタル画像の有用性)

4.臨床におけるDRの有用性とその将来(ディジタル画像の有用性)

4.臨床におけるDRの有用性とその将来(ディジタル画像の有用性)

Are Digital Chest X-rays Good Enough?

I am writing about the growing use of digital radiography (teleradiology) for chest x-rays. I solicit responses from other more knowledgeable chest physicians regarding their experience and recommendations for this new technology.

Digital radiographyにおける付加フィルタの有用性

digital radiographyにおける付加フィルタの有用性

Scatter rejection by air gaps in diagnostic radiology. Calculations using a Monte Carlo collision density method and consideration of molecular interference in coherent scattering

The air gap technique is an old method for scatter rejection. It is still used in lung examinations and may be reconsidered for use in digital radiography. Using magnification techniques, for example in mammography, the air gap thereby introduced simultaneously yields scatter rejection. A Monte Carlo collision density method is exploited to investigate the physical parameters relevant to this technique. Radiation quantities of scattered photons at points behind a water slab both on and laterally displaced from the central axis are calculated and their dependence on field area, slab thickness, air gap length and detector type is derived. Values of `scatter-to-primary' ratios of the plane energy fluence (the energy imparted to a totally absorbing detector) are given for perpendicularly incident 30, 70 and 130 kV energy spectra, slab thicknesses of 0.05 and 0.2 m (30 kV: 0.05 m), air gaps of length 0.002 - 1.0 m and field areas from to . Contrast degradation factors are derived for both totally absorbing and thin detectors. The influence on the scatter-to-primary ratios of using divergent instead of parallel beams and of neglecting molecular interference in coherent scattering is analysed.

Clinical usefulness of digital radiography in the gastrointestinal tract: efficacy of magnification method.

We assessed the performance capabilities of image intensifier digital radiography (II DR) in the detection of minute lesions in patients with early stomach cancer. The DR system was a prototype II DR system developed by Toshiba Corp (Tokyo, Japan). This system was able to acquire images with a 1,024- x 1,024-pixel matrix and 12 bits. Radiography was performed using a 0.3-mm tube focus. For the detectability of early stomach cancer, DR was judged to be superior to conventional screen-film system (CFSS) (DR superior, 55.7%; CFSS superior, 22.6%). In depicting the characteristics of the surface of the lesion, DR was also judged to be superior to CFSS (DR superior, 56.6%; CFSS superior, 17.0%). The II DR system used in this study was able to achieve almost the same spatial resolution as conventional radiography using the magnification method. It was also able to visualize subtle findings of early gastric cancer more clearly by the use of postprocessing. In addition, II DR has the advantages of reducing the patient exposure dose and permitting the acquisition of real-time images.

Application of digital radiography and PACS in a senology department

The use of digital radiography involves significant advantages by virtue of its superior image quality, sensitivity, image-processing capacity and exposure dose reduction.

NEW AND FUTURE DEVELOPMENTS IN SCREEN-FILM MAMMOGRAPHY EQUIPMENT AND TECHNIQUES

Two improvements in mammography equipment during the last 4 years will greatly affect the practice of mammography during the next decade: dose reduction and improved testing equipment for monitoring the quality of mammography. The increased use of digital radiography has stimulated studies comparing digital mammography with screen-film mammography. Some digital algorithms for detecting clusters of calcifications may have application in screening mammography within the next decade.

Use of digital radiography to demonstrate the potential of naproxen as an adjunct in the treatment of rapidly progressive periodontitis

The effect of the non-steroidal anti-inflammatory drug, naproxen, in reducing periodontal disease activity was assessed in 15 patients with rapidly progressive periodontitis. All patients in this double-blind study were treated with scaling and root planing. Thereafter, 7 patients receiving 500 mg naproxen b.i.d. for 3 months, and 8 patients received placebo. Disease activity was assessed in three ways. First, alveolar bone height was determined using standardized radiography. Second, alterations in alveolar bone metabolism were assessed using 99m-Tc-methylene diphosphonate uptake prior to dosing and 3 months later. Finally, bone loss or gain was detected using digital subtraction radiography. In this study, conventional subtraction images were processed to isolate the area of change and superimpose the change on the original radiograph. This allowed determination of both the direction and location of osseous changes. There was significantly less bone loss as determined by analysis of bone height during the 3-month study in the naproxen-treated patients when compared to the placebo-treated patients (p less than 0.001). Radiopharmaceutical uptake was significantly reduced in the alveolar bone in patients receiving naproxen (p less than 0.03), whereas no significant change was observed in the placebo-treated patients. Furthermore, the subtraction radiographs showed a significant increase in the proportion of teeth demonstrating bone gain in the naproxen-treated group. These findings indicate that naproxen may be a useful adjunct to scaling and root planing in patients with rapidly progressive periodontitis.

Computed radiography in neonatal intensive care

The Authors report their experience in the employment of a computerized digital radiographic system in Neonatal Intensive Care. The analog screen-film system is replaced by photosensitive imaging plates, scanned after X-ray exposure by a laser that releases the digital image, which can then be manipulated on computer work-stations. In a period of twelve months about 200 chest-abdomen X-ray examinations in Neonatal Intensive Care have been performed using this method with good technical and diagnostic results. The use of digital radiography in the neonatal area is of high interest: this system produces good quality images, there is a reduction in radiation dose and 'retakes', the system allows selective enhancement of different structures and their magnification.

Digitale Bildverstärker-Radiographie - Einjährige Erfahrung mit einem Polytron-System

Since January 1988, digital image intensifier radiography has been used in the Clinic in Mannheim for DSA examinations and also in place of conventional screen/film examinations. Measurements have shown that compared with 100 mm and film/screen formats, digital radiography has poorer spatial resolution, but improved contrast resolution. The most common use of digital radiography was for examinations of the gastrointestinal tract. Using the demonstration of the mucosal fine relief pattern as a criterion of image quality, digital image intensifier radiography was able to achieve this satisfactorily. Comparison with film/screen examinations showed no loss of diagnostic information. Advantages of image intensifier radiography are reduced radiation dose, the possibility of postprocessing and economy. On the basis of 399 examinations, digital image intensifier radiography is now firmly established as part of the daily routine of the Mannheim Clinic.