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PubMed2004

Secondary caries detection by DIAGNOdent and radiography: a comparative in vitro study.

DIAGNOdent is now well documented for detection of primary occlusal caries, but not as yet for secondary caries. The aim of this study was to investigate the application of DIAGNOdent for in vitro detection of secondary caries. The material comprised 66 extracted teeth: 48 with amalgam restorations and 18 with tooth-colored restorations. Digital images of occlusal surfaces were captured for each specimen. The teeth were mounted in groups of 3 or 4 in plaster blocks simulating their anatomical positions. Bitewing radiographs of each block were assessed for secondary caries by 5 observers. The margins of each restoration were carefully scanned with DIAGNOdent; the site of the highest reading was localized in digital images; and the corresponding values were registered. Marginal integrity and staining were also documented. The restorations were then removed and the teeth were hemi-sectioned. For verification, two observers working together examined all the cavities under a stereomicroscope at 16 x magnification followed by probing. Sensitivity and specificity for DIAGNOdent and conventional radiography were 0.77/0.81 and 0.65/0.81, respectively. Regarding ROC analyses, the Az values were 0.89 and 0.72 for DIAGNOdent and radiography. For DIAGNOdent, the false-positive fraction included only stained teeth. Cohen's kappa statistics disclosed moderate agreement between the 2 methods, with an agreement of 56%. DIAGNOdent tended to give more positive diagnoses than bitewing radiography. The results indicate that DIAGNOdent may be a helpful tool for detecting secondary caries.

Color↗

PubMed1993

Cervical spine radiography after blunt trauma. Is it always needed?

In trauma cases, the mere presence of a cervical immobilization device is not an indication for radiography of the cervical spine. High-yield radiographic criteria have been prospectively determined for cases of blunt trauma, and these identify individuals at low risk for cervical spine injuries. Cervical spine radiography is not required for patients who are alert, cooperative, and nonintoxicated and do not have neurologic deficits, cervical signs or symptoms, antecedent spinal mobility disorders, or distracting injuries. Cervical spine radiography alone does not ensure detection of all injuries. Adequate history taking and careful examination are always essential and may dictate additional studies.

Cervical Vertebrae↗

PubMed2003

Comparison of indirect CsI/a:Si and direct a:Se digital radiography. An assessment of contrast and detail visualization.

PURPOSE: To assess and quantify the image quality at two dose levels for an amorphous Silicon (a:Si) Cesium Iodide (CsI) flat panel system compared with a direct amorphous Selenium (a:Se) digital radiography system. MATERIAL AND METHODS: A contrast detectability test was performed employing the CDRAD-phantom at mAs-values leading to approximately equal phantom entrance doses of 41.4, 57.9, 75.1 and 120.8 micro Gy for the a:Se and 39.9, 58.4, 75.6 and 117.9 micro Gy for the CsI system. Images were presented to 4 independent observers. For quantitative comparison, the image quality figure (IQF) was calculated. Statistical analysis was performed using Pearson's correlation and the Wilcoxon test. A ROC-analysis was performed employing the TRG-phantom in a high- and a low-dose setting leading to entrance doses of 126.2 and 35 micro Gy for the direct, and 125.9 and 34.4 micro Gy for the indirect system. Statistical significance was evaluated using the Wilcoxon test. RESULTS: The flat panel a:Si digital system provided superior results compared with the a:Se drum digital system with respect to low-dose settings for CDRAD-phantom and ROC-analysis, ensuring a better image quality with respect to contrast and detail detectability. Higher-dose settings provided similar results for both systems. CONCLUSION: Image quality of a:Si flat panel digital radiography proved to be superior to a:Se drum digital radiography using low-dose settings. If the primary target is dose reduction indirect flat panel technology should be used.

Cesium↗

PubMed1999

Plain radiography of the lumbosacral spine. An audit of referrals from general practitioners.

PURPOSE: To evaluate how referrals from Norwegian general practitioners for plain radiography of the lumbosacral spine conform to clinical recommendations, and whether non-conforming referrals yield important findings. MATERIAL AND METHODS: The clinical information reported in referral letters of 323 patients was compared with recommendations given in a Norwegian and in a British "guide". Additional clinical data were obtained by interviewing 100 of the patients. Using all available information, a new comparison was performed. Radiological findings were obtained from the routine reports. RESULTS: Of the 323 referrals, 24% (37%) conformed to the Norwegian (British) "guide", 34% (46%) did not conform, and 42% (18%) were considered uncertain, mainly because of lack of pertinent information in the referral letters. A total of 182 examinations were in disagreement with one or both "guides". Only 4 of these examinations revealed potentially important findings (osteoporotic fractures in 2 patients, uncertain sacroiliac joint arthritis in 1 patient, and "probably benign" sclerotic densities in 1 patient). In the interview group, the proportion of non-conforming referrals was 40% (48%) based on the referral letters, and 31% (30%) when the interview data were taken into account. CONCLUSION: A great proportion of referrals for plain radiography of the lumbosacral spine do not conform to recent clinical recommendations. Referrals outside the advised criteria yield few relevant findings and could probably be cancelled. They require at least supplementary information to justify radiography.

Adolescent↗

PubMed2003

Magnetic resonance imaging of the fifth metatarsophalangeal joint compared with conventional radiography in patients with early rheumatoid arthritis.

OBJECTIVE: To evaluate if magnetic resonance imaging (MRI) is superior to conventional radiography for detection of erosions in the fifth metatarsophalangeal (MTP5) joint. METHODS: Within one year from the onset of rheumatoid arthritis (RA) (baseline), one and three years thereafter MRI and conventional radiographs of the MTP5 joint were performed in 23 patients. RESULTS: MRI revealed erosions in 10 patients at baseline, in 15 after one year and in 15 patients after 3 years. On conventional radiography, there were erosions in 10 patients at baseline, 16 after one year as well as after 3 years. The agreement between the two imaging methods was fair to good at baseline and after one and three years (kappa 0,65, 0,51 and 0,51 respectively). The number of patients with clinical evidence of synovitis decreased considerably over time although the number of patients with MRI-synovitis was unchanged and the number of patients with erosions increased. CONCLUSIONS: MRI was not superior to conventional radiography in detecting erosions in MTP5 joints in patients with early RA. Most erosions developed during the first year of observation. Synovitis on MRI may be a marker of future development of erosions in the MTP5 joint.

Adult↗

PubMed2003

Gastro-esophageal reflux demonstrated by radiography in infants less than 1 year of age. Comparison with pH monitoring.

PURPOSE: To correlate gastro-esophageal reflux (GER) demonstrated on radiography, with reflux determined on 24-h pH monitoring among infants of less than 1 year of age. MATERIAL AND METHODS: Twenty-one infants with suspected GER were examined. In the supine position the infants drank 20-60 ml of barium contrast, and the presence or absence of hiatal hernia, gastric outlet obstruction, or intestinal malrotation was evaluated. The infant was placed in the 25 degrees right oblique supine position and fed 2-3 swallows of milk by a feeding bottle. GER was scored as positive on radiography when the contrast column reached a level of at least 3 vertebral segments above the gastro-esophageal junction (GEJ). An antimony intraluminal esophageal pH probe was positioned 2 vertebral segments above the GEJ as identified by the barium swallow, confirmed on radiography after positioning and prior to probe removal. A total time of esophageal pH <4 exceeding 5% was assigned as pathological. RESULTS: The radiological method of GER evaluation showed a specificity of 50% and a sensitivity of 29%, as compared to 24-h pH monitoring. CONCLUSION: The radiological method was of no value among infants of less than 1 year when demonstrating GER.

Female↗

PubMed1994

The contrast-detail behaviour of a photostimulable phosphor based computed radiography system.

Contrast-detail measurements were performed on a computed radiography imaging system as a function of detector entrance air kerma over the dose range from 0.743 microGy (0.085 mR) to 277 microGy (31.8 mR). A theoretical model of contrast-detail behaviour for a photostimulable phosphor computed radiography system has been derived, which is based on a modified version of the Rose theory of threshold detection. Included in the model are both system and x-ray quantum noise terms, as well as the response of the eye. The zero-frequency noise power of the computed film images was measured with a double-beam scanning microdensitometer. For a given detector dose, good agreement was found between the predicted and measured data when this measurement of system noise was included in the model. The contrast-detail results obtained for the computed radiography system were also compared with contrast-detail results for an image intensifier-TV based digital imaging system and a conventional film-screen system.

Air↗

PubMed2002

Signal-to-noise ratio evaluation in dual-energy radiography with synchrotron radiation.

Dual-energy radiography is an effective technique that allows removal of contrast between pairs of materials in order to display details of interest on a uniform background. In mammographic images the detection of small nodules is often impeded by obscuring background 'clutter' resulting from the contrast between normal tissues (glandular and adipose) in their neighbourhood. We consider whether it could be possible to apply dual-energy radiography to the breast, which is hypothetically principally composed of three tissues, glandular, adipose and cancerous, in order to remove the contrast due to the distribution of normal tissues and, as a consequence, to enhance the intrinsic contrast of the pathology. The purpose of this work is to test the limitations of dual-energy radiography on a three-component phantom under optimum conditions of the source and detector. We use a synchrotron monochromatic beam, produced at the ELETTRA synchrotron facility (Trieste, Italy), and an imaging plate detector, in order to acquire two images at low and high energies of a phantom composed of polyethylene, plexiglas and water. For evaluation of the potential of this procedure we studied the signal-to-noise ratio (SNR) of polyethylene and water on a set of images obtained by applying the dual-energy procedure. We found that the SNR of polyethylene and water is around the detectability threshold (according to Rose's criteria) at the contrast cancellation angles. Finally we evaluated the air entrance dose required for this double exposure, resulting in 0.81 mGy for the low-energy image and 0.01 mGy for the high-energy image. To obtain the same image quality for a standard breast of 5.5 cm, mean glandular doses of 3.50 mGy and 0.03 mGy at 17 keV and at 34 keV, respectively, are required.

Algorithms↗

PubMedDate not supplied

Methods: a comparative analysis of radiography, microcomputed tomography, and histology for bone tissue engineering.

This study focused on the assessment of radiography, microcomputed tomography, and histology for the evaluation of bone formation in a 15.0-mm defect in the rabbit radius after the implantation of a tissue-engineered construct. Radiography was found to be useful as a noninvasive method for obtaining images of calcified tissue throughout the time course of the experiment. With this method, however, image quality was low, making it difficult to obtain precise information about the location and quantity of the bone formed. Microcomputed tomography was used to create three-dimensional reconstructions of the bone (25-microm resolution). These reconstructions allowed for greater spatial resolution than the radiography, but did not allow for imaging of the implanted scaffold material or the surrounding, nonmineralized tissue. To visualize all materials within the defect area at the cellular level, histology was used. Histological analysis, however, is a destructive technique that did not allow for any further analysis of the samples. Each technique examined here has its own advantages and limitations, but each yields unique information regarding bone regeneration. It is only through the use of all three techniques that complete characterization of the bone growth and tissue/construct responses after implantation in vivo.

Acrylates↗

PubMed1975

Breast specimen radiography. Obligatory, adjuvant and investigative.

The development of mammography and that of breast specimen radiography, which have paralleled one another, are reviewed. The preparation of radiographs of breast specimens is obligatory when biopsy is performed for purely mammographic indications and when no palpable mass is present. Such cases are being encountered with increasing frequency because of the development of centers for breast cancer screening. Close collaboration among pathologists, radiologists and surgeons and precise attention to procedural detail are necessities wherever this situation arises. The application of specimen radiography as a routine to all breast specimens is regarded as an adjunct to gross examination. While useful, its yield of otherwise undetected occult carcinoma is low. Whether other advantages outweigh the cost appears to be a matter for individual decision. Investigative uses of breast specimen radiography have received little attention. Some possible applications are suggested.

Breast Neoplasms↗

PubMed2001

Clinical aspects of quality criteria in digital radiography.

In clinical radiological practice two main questions regarding image quality have to be looked at: Which degree of image quality is needed? and: How can this image quality be objective? Image quality requirements depend on size, density and contrast of the objects of interest and on the clinical question which has to be answered. In comparison to conventional radiography, the digital radiographic techniques offer additional features concerning optimisation of image quality and dose, like a wider dynamic range, digital fluoroscopic techniques and post-processing. Therefore it is necessary to define new quality criteria for these techniques. In the following, typical examples demonstrate the development of the 'Diagnostic Requirements for Digital Radiographic Procedures'. These examinations include projection radiographs with digital luminiscent radiography, fluoroscopic procedures with digital image intensifier radiography and angiographic procedures with digital subtraction angiography. The clinical question of a radiological examination also forms the background to optimisation strategies considering image quality and radiation dose.

European Union↗

PubMed2005

Occupational exposure in Greek industrial radiography laboratories (1996-2003).

More than 40 industrial radiography laboratories are operating in Greece using X-ray or gamma-ray sources and more than 250 workers occupationally exposed to ionising radiation in these facilities are monitored on a regular basis. This study presents the evolution of individual doses received by radiographers during the past years. The mean annual dose (MAD) of all workers as well as of exposed workers is estimated, and correlated to the types of laboratories and practices applied. The MAD of the exposed workers in industrial radiography is compared with the doses of workers in other specialties and with the doses of radiographers in other countries. Furthermore, the study attempts to propose dose constraints for the practices in industrial radiography, according to the BSS European directive and the relevant Greek radiation protection legislation. The proposed value was defined as the dose below which the annual doses of 75% of the exposed radiographers are expected to be included.

Gamma Rays↗

PubMed2006

Image quality and dose management in digital radiography: a new paradigm for optimisation.

The advent of digital imaging in radiology, combined with the explosive growth of technology, has dramatically improved imaging techniques. This has led to the expansion of diagnostic capabilities, both in terms of the number of procedures and their scope. Throughout the world, film/screen radiography systems are being rapidly replaced with digital systems. Many progressive medical institutions have acquired, or are considering the purchase of computed radiography systems with storage phosphor plates or direct digital radiography systems with flat panel detectors. However, unknown to some users, these devices offer a new paradigm of opportunity and challenges. Images can be obtained at a lower dose owing to the higher detective quantum efficiency (DQE). These fundamental differences in comparison to conventional film/screens necessitate the development of new strategies for dose and quality optimizations. A set of referral criteria based upon three dose levels is proposed.

Humans↗

PubMed1998

Detection of osteomyelitis in the neuropathic foot: nuclear medicine, MRI and conventional radiography.

The diagnostic efficacy of (1) combined three-phase bone scintigraphy and In-111 labeled WBC scintigraphy (Bone/WBC), (2) MRI, and (3) conventional radiography in detecting osteomyelitis of the neuropathic foot was compared. Conventional radiography was comparable to MRI for detection of osteomyelitis. MRI best depicted the presence of osteomyelitis in the forefoot. Particularly in the setting of Charcot joints, Bone/WBC was more specific than conventional radiography or MRI.

Adult↗

PubMedDate not supplied

Abdominal computed radiography: evaluation of low-constrast lesions.

Computed radiography has proved useful as a localization device for computed tomography. In an attempt to evaluate computed radiography as a primary diagnostic device, 16 patients were evaluated with various degrees of gallbladder opacification following standard oral cholecystograms, and 15 patients were evaluated with renal masses, identified on standard excretory urography. Subjective evaluation of computed radiographs as compared to the standard radiographs demonstrated no diagnostic advantage to computed radiography. The poor spatial resolution of the computed radiographs was not overcome by the improvement in contrast resolution.

Cholecystography↗

PubMed1992

Development of a 2,048 x 2,048-pixel image intensifier-TV digital radiography system. Basic imaging properties and clinical application.

RATIONALE AND OBJECTIVES: A 2,048 x 2,048-pixel matrix image intensifier (II)-TV digital radiography system has been developed. Potential clinical applications of this new II-TV system were investigated. METHODS: Basic imaging properties were assessed with clinical applications to gastrointestinal (GI) tract and chest examinations. RESULTS: Basic imaging properties showed improvement of modulation transfer functions (MTFs) from the 1,024 x 1,024- to the 2,048 x 2,048-pixel matrix and approximated the screen-film system at low spatial frequencies. Receiver operating characteristic (ROC) curves of simulated linear shadows improved similarly. Clinical applications showed that the image quality of the 2,048 x 2,048-pixel matrix was comparable with that of the screen-film system for upper GI and chest radiography, but the image quality of the screen-film system was better for the lower GI tract. CONCLUSIONS: The authors' II-TV digital radiography system is clinically applicable to gastrointestinal and chest examinations.

Digestive System↗

PubMed1980

A comparison of upper gastrointestinal endoscopy and radiography.

One hundred symptomatic patients were evaluated independently with upper gastrointestinal radiography and fiberoptic endoscopy, and the results were compared. Of the two endoscopists sequentially examining the same patient, one was informed of available clinical and radiographic details and the other was not. Knowledge of the x-ray examination by the informed endoscopist did not improve his accuracy. Each endoscopist made four errors of interpretation. The endoscopic and x-ray findings agreed in 46 of the 100 patients, most often (68%) in esophagus, least often (29%) in the stomach and half the time (45%) in the duodenum. Ulcer craters seen endoscopically were detected radiographically in 36% of patients. We conclude that: 1) knowledge of results of prior upper gastrointestinal radiography did not alter endoscopic results; 2) experienced endoscopists are accurate but make mistakes; and 3) endoscopic findings would have been unaltered had radiography not been performed.

Diagnostic Errors↗

PubMed1985

Chest equalization radiography.

The conventional chest radiograph has a number of limitations as a diagnostic method of evaluating chest disease. The wide variation in attenuation between the lung and mediastinum frequently results in images with low contrast over the thicker portions. This, coupled with the presence of intense body-scattered radiation that must be adequately removed, makes chest radiography one of the most challenging diagnostic procedures in conventional radiography. Scanning equalization radiography (SER) is an alternative method of chest imaging that overcomes these limitations without employing other highly complex or expensive solutions such as digital imaging. Recent clinical studies have shown that diagnostic efficacy is improved with SER, and that SER offers the potential of significantly reducing the frequency of diagnostic errors and repeated examinations while producing cost savings.

Bone Diseases↗