Clinical performance of Siemens digital breast tomosynthesis versus standard supplementary mammography for the assessment of screen-detected soft-tissue abnormalities: a multi-reader study.

AIM: To compare the diagnostic accuracy of standard screening images plus single-view digital breast tomosynthesis (DBT), using Siemens DBT equipment, with standard screening images plus supplementary mammographic views in non-calcific, screen-detected mammographic abnormalities. MATERIALS AND METHODS: Participants were unselected women aged 50-69 years recalled within a population-based European breast screening programme for assessment of soft-tissue mammographic abnormalities. Supplementary mammographic views (SMVs) and DBT were performed in all cases. A range of equipment was used for screening and supplementary mammography, but all DBT examinations were performed using the Siemens Mammomat Inspiration. A retrospective multi-reader study including 238 cases for whom either histology or at least 2 years' follow-up was available was performed with eight suitably accredited UK breast screening personnel reading all cases under both conditions, with temporal separation. Readers were blinded to case outcomes and findings from other examinations. Diagnostic accuracy using receiver operating characteristic (ROC) analysis was compared between screening plus SMV images and screening plus DBT images. The study was powered to detect a 3% inferiority margin in diagnostic accuracy between methods. RESULTS: The final sample with complete data available for analysis included 195 benign cases (1,560 reads) and 35 malignant cases (280 reads). The DBT method yielded a slightly higher area under the curve (AUC) value than the SMV method (0.870 versus 0.857), but the difference was not statistically significant (p=0.4890), indicating that the methods have equivalent accuracy. CONCLUSION: Siemens DBT demonstrates equivalent diagnostic accuracy according to ROC curve analysis when used in place of SMVs in screen-detected soft-tissue mammographic abnormalities.

Radiographic methods used before removal of mandibular third molars among randomly selected general dental clinics.

OBJECTIVES: To assess radiographic methods and diagnostically sufficient images used before removal of mandibular third molars among randomly selected general dental clinics. Furthermore, to assess factors predisposing for an additional radiographic examination. METHODS: 2 observers visited 18 randomly selected clinics in Denmark and studied patient files, including radiographs of patients who had their mandibular third molar(s) removed. The radiographic unit and type of receptor were registered. A diagnostically sufficient image was defined as the whole tooth and mandibular canal were displayed in the radiograph (yes/no). Overprojection between the tooth and mandibular canal (yes/no) and patient-reported inferior alveolar nerve sensory disturbances (yes/no) were recorded. Regression analyses tested if overprojection between the third molar and the mandibular canal and an insufficient intraoral image predisposed for additional radiographic examination(s). RESULTS: 1500 mandibular third molars had been removed; 1090 had intraoral, 468 had panoramic and 67 had CBCT examination. 1000 teeth were removed after an intraoral examination alone, 433 after panoramic examination and 67 after CBCT examination. 90 teeth had an additional examination after intraoral. Overprojection between the tooth and mandibular canal was a significant factor (p < 0.001, odds ratio = 3.56) for an additional examination. 63.7% of the intraoral images were sufficient and 36.3% were insufficient, with no significant difference between images performed with phosphor plates and solid-state sensors (p = 0.6). An insufficient image predisposed for an additional examination (p = 0.008, odds ratio = 1.8) but was only performed in 11% of the cases. CONCLUSIONS: Most mandibular third molars were removed based on an intraoral examination although 36.3% were insufficient.

A clinical comparison of extraoral panoramic and intraoral radiographic modalities for detecting proximal caries and visualizing open posterior interproximal contacts.

OBJECTIVES: The purpose of this study was to compare extraoral panoramic bitewings (BWs) to intraoral photostimulable phosphor (PSP) plate BWs for the detection of proximal surface caries and to establish if there was any difference between extraoral BWs, intraoral BWs and panoramic radiographs in visualizing open posterior interproximal contacts. METHODS: Extraoral panoramic and intraoral BW images were acquired on each of 20 patients, resulting in 489 total non-restored, readable surfaces that were evaluated by 4 observers. The ANOVA analysis to determine diagnostic variability between and within each subject was utilized. The surfaces included in the study extended from the distal of each canine to the last posterior contact in each arch with non-readable proximal surfaces excluded (i.e.surfaces where over half the enamel layer was overlapped or where those surfaces were not visible in one or both modalities). RESULTS: The statistical analysis indicated that the overall mean area under the receiver operating characteristic curves across all observers for the intraoral BWs and extraoral panoramic BWs were 0.832 and 0.827, respectively, and the difference of 0.005 was not significant at p = 0.7781. The percentage of non-readable proximal surfaces across the three modalities was 4.1% for intraoral BWs, 18.3% for extraoral panoramic BWs and 51.5% for the standard panoramic images. CONCLUSIONS: The investigators concluded there was no significant difference in posterior proximal surface caries detection between the modalities. Extraoral panoramic BWs were much better than panoramic radiographs in visualizing open posterior interproximal contacts, 81.7% vs 48.5%, but below the 95.9% value for intraoral BWs.

Ex vivo evaluation of new 2D and 3D dental radiographic technology for detecting caries.

OBJECTIVES: Proximal dental caries remains a prevalent disease with only modest detection rates by current diagnostic systems. Many new systems are available without controlled validation of diagnostic efficacy. The objective of this study was to evaluate the diagnostic efficacy of three potentially promising new imaging systems. METHODS: This study evaluated the caries detection efficacy of Schick 33 (Sirona Dental, Salzburg, Austria) intraoral digital detector images employing an advanced sharpening filter, Planmeca ProMax(®) (Planmeca Inc., Helsinki, Finland) extraoral "panoramic bitewing" images and Sirona Orthophos XG3D (Sirona Dental) CBCT images with advanced artefact reduction. Conventional photostimulable phosphor images served as the control modality. An ex vivo study design using extracted human teeth, ten expert observers and micro-CT ground truth was employed. RESULTS: Receiver operating characteristic analysis indicated similar diagnostic efficacy of all systems (ANOVA p > 0.05). The sensitivity of the Schick 33 images (0.48) was significantly lower than the other modalities (0.53-0.62). The specificity of the Planmeca images (0.86) was significantly lower than Schick 33 (0.96) and XG3D (0.97). The XG3D showed significantly better cavitation detection sensitivity (0.62) than the other modalities (0.48-0.57). CONCLUSIONS: The Schick 33 images demonstrated reduced caries sensitivity, whereas the Planmeca panoramic bitewing images demonstrated reduced specificity. XG3D with artefact reduction demonstrated elevated sensitivity and specificity for caries detection, improved depth accuracy and substantially improved cavitation detection. Care must be taken to recognize potential false-positive caries lesions with Planmeca panoramic bitewing images. Use of CBCT for caries detection must be carefully balanced with the presence of metal artefacts, time commitment, financial cost and radiation dose.

Diagnostic accuracy of conventional and digital radiography for detecting misfit between the tooth and restoration in metal-restored teeth.

STATEMENT OF PROBLEM: Although the postprocessing of digital images with enhancement filters could lead to the presence of artifacts and result in false-positive diagnoses, no study has analyzed whether the use of digital radiographs and/or postprocessing of digital images interferes with the diagnosis of marginal adaptation in metal-restored teeth. PURPOSE: The purpose of this study was to compare the diagnostic accuracy of conventional and digital radiographic images with and without filters for detecting a misfit between the tooth and restoration in metal-restored teeth. MATERIAL AND METHODS: Forty teeth with mesial-occlusal-distal inlays and 40 with complete crowns (each with a perfect fit, 20 with a 0.2-mm gap and 20 with a 0.4-mm gap) were imaged with conventional film and digital phosphor plate systems. Digital radiographs were exported as original images and with edge enhancement (high and low), inversion, and pseudo-3-dimensional filters. Four examiners assessed the presence of gaps by using a categorical scale (fit, misfit, cannot decide). Sensitivity, specificity, and overall accuracy were calculated for each variable. In addition, time spent scoring the images was recorded. A multivariate logistic regression was performed with accuracy as the dependent variable. RESULTS: Of the images, 6.2% received the score "cannot decide," most of them with a high edge enhancement filter and in the crown group. A tendency for higher sensitivity (range 0.67-0.83), specificity (range 0.81-0.92), and accuracy (range 0.73-0.86) values was found in conventional and digital original images. Results of a logistic regression found that restoration type, gap size, and high enhancement and inversion filters had a statistically significant impact on accuracy (P<.05). CONCLUSIONS: Original nonfiltered images should be used to assess teeth with metal restorations. High enhancement filters and image inversion should be avoided, especially when metal crowns are present.

A comparative study of different radiographic methods for detecting occlusal caries lesions.

OBJECTIVES: The aim of this in vitro study was to compare the diagnostic accuracy of different radiographic imaging modalities in detecting occlusal caries lesions. MATERIALS AND METHODS: Under standardized conditions, 125 extracted human permanent molar teeth with sound or occlusal caries lesions were radiographed using a conventional film system (F-speed), a direct digital imaging system (complementary metal oxide semiconductor sensor), an indirect digital imaging system (photostimulable phosphor plate) and a cone beam computed tomography system (CBCT). Two observers scored the resultant images for the presence or absence of caries. Then, the teeth were histologically prepared and a definite diagnosis was determined by stereomicroscopic assessment. The area under the receiver operating characteristic curve (Az), sensitivity, specificity and accuracy of each imaging modality were calculated, as well as the intra- and interexaminer reproducibility. RESULTS: For both thresholds, interexaminer agreement were higher for CBCT. For intraexaminer agreement, observers had different scores for both thresholds, but the scores were generally higher for CBCT. Similar Az values were achieved with all imaging methods at a diagnostic D1 threshold. The Az values of the CBCT system were found to be statistically higher than those of the other imaging modalities at a diagnostic D3 threshold (p > 0.05); no significant differences were found among the other imaging modalities. All radiographic methods showed similar sensitivities, specificities and accuracy in detecting D1 threshold. The CBCT system showed higher sensitivity and accuracy in detecting dentine lesions. CONCLUSIONS: Within the limitations of this study, CBCT exhibited better performance in detecting deep occlusal caries lesions than the other radiographic systems.

In vitro comparison of contemporary radiographic imaging techniques for measurement of tooth length: reliability and radiation dose.

OBJECTIVES: To measure the reliability of tooth length measurements taken using dental pantomograms (DPT), long cone periapical radiographs (PR), and cone beam computed tomography (CBCT) and to compare their effective radiation dose. SUBJECTS AND METHODS: A model containing sixteen anterior teeth was used to simulate a patient undergoing fixed appliance treatment. PRs were taken at standardized vertical angulations to the occlusal plane (0, 5, 10, 15, and 20°) using conventional and digital techniques. DPT and CBCT images were also taken. Measurements of radiation dosages were used to estimate a risk benefit analysis for each of the techniques. RESULTS: DPT consistently overestimated tooth lengths by 2 mm or more [mean: 2·34 mm; 95% confidence interval (CI): 1·4-3·3 mm]. CBCT consistently underestimated tooth length (mean: -0·89 mm; 95% CI: -0·44 to -1·33 mm). PRs taken at 90° angulation closely resembled the actual tooth length (mean: -0·14 mm; 95% CI: -0·64 to 0·37 mm), but overestimation occurred with increasing PR film angulation. The radiation dosages ranged widely: DPT plus eight PRs that would be necessary to assess all teeth and root length of the upper and lower labial segments amounted to 23 µSv. Radiation dose from CBCT ranged from 17·8 to 60 µSv, depending on equipment and settings.

[Flat detector computed tomography in diagnostic and interventional pediatric cardiology]. / Flachdetektor-Computertomografie in der diagnostischen und interventionellen Kinderkardiologie.

PURPOSE: In this study the use of flat detector computed tomography (FD-CT) in the catheterization of patients with congenital heart disease was evaluated. Application reports were created for various issues based on the achieved image quality in diverse anatomical regions. MATERIALS AND METHODS: FD-CT was applied in 176 cases during catheterization between January 2010 and April 2012. A five-point Likert scale ("essential" to "misleading") was used to evaluate image quality. All cases were analyzed retrospectively and application reports for the visualization of the aorta, pulmonary arteries, pulmonary veins, semilunar valves, cavopulmonary connections and atrial baffles were generated. Contrast dye consumption and radiation dose were evaluated. RESULTS: During the observation period FD-CT was applied in all 176 cases. The mean patient age was 7.0 years (0.01 - 42.53 years). The clinical value of FD-CT was rated superior to conventional angiography in 96.6 % of the cases and was never rated as "misleading". FD-CT was rated "essential" in 3.4 % of all cases, "very useful" in 77.3 % of all cases, "useful" in 15.9 % of all cases and "not useful" in 3.4 % of all cases. The mean dose-area product was 99 µGym2 (19.3 - 1276.6 µGym2), and the used contrast dye was 1.76 ml/kg (0.9 - 5 ml/kg). Application reports for the visualization of different anatomical regions are demonstrated. CONCLUSION: FD-CT is a new and auxiliary procedure in diagnostic and interventional catheterization of patients with congenital heart disease. Particularly extracardiac structures can be displayed in three-dimensional high resolution and be used for diagnosis, surgical planning and 3 D navigation.

Reliability and validity of soft copy images based on flat-panel detector in pneumoconiosis classification: comparison with the analog radiographs.

RATIONALE AND OBJECTIVES: The aim of this study was to evaluate the reliability and validity of soft copy images based on flat-panel detector of digital radiography (DR-FPD soft copy images) compared to analog radiographs (ARs) in pneumoconiosis classification and diagnosis. MATERIALS AND METHODS: DR-FPD soft copy images and ARs from 349 subjects were independently read by four-experienced readers according to the International Labor Organization 2000 guidelines. DR-FPD soft copy images were used to obtain consensus reading (CR) by all readers as the gold standard. Reliability and validity were evaluated by a κ and receiver operating characteristic analysis, respectively. RESULTS: In small opacity, overall interreader agreement of DR-FPD soft copy images was significantly higher than that of ARs, but it was not significantly different in large opacity and costophrenic angle obliteration. In small opacity, agreement of DR-FPD soft copy images with CR was significantly higher than that of ARs with CR. It was also higher than that of ARs with CR in pleural plaque and thickening. Receiver operating characteristic areas were not different significantly between DR-FPD soft copy images and ARs. CONCLUSIONS: DR-FPD soft copy images showed accurate and reliable results in pneumoconiosis classification and diagnosis compared to ARs.

Advantages of fitting contrast curves using logistic function: a technical note.

OBJECTIVE: The aim of this article is to demonstrate how the contrast properties of an imaging system can be ideally fitted with the use of stripe patterns and the logistic function. STUDY DESIGN: Stripe patterns with defined amounts of line pairs (lp/mm) per mm (10-20 lp/mm) were recorded with the use of digital photostimulable storage phosphor. Scan data and normalized image data were analyzed with the use of ImageJ and MatLab to calculate different contrast curves. RESULTS: For original scan data, the goodness of fit was 0.0000019 (sum of squared error [SSE]). The R-square was 0.9998. For normalized data the goodness of fit was 0.0007 (SSE) and the R-square 0.998. An amount of 50% contrast could be calculated to be found on 11.67 lp/mm in normalized images. CONCLUSIONS: This article addresses a potentially new approach to compare digital x-ray modalities using a direct assessment of a known technical target.

Difference in dose area product between analog image intensifier and digital flat panel detector in peripheral angiography and the effect of BMI.

PURPOSE: Comparison of dose area products (DAP) in diagnostic angiography procedures between an image intensifier (II) and a flat panel detector (FPD) angiography system and the evaluation of DAP/body mass index (BMI) dependency. MATERIALS AND METHODS: An image intensifier system or a flat panel detector system was used to perform 571 diagnostic angiographies (n = 328 and n = 243, respectively) of 5 different types: peripheral arterial, venous, single leg, abdominal and upper extremity. The results were retrospectively analyzed. The DAP, fluoroscopy time (t) and the number of series of the respective interventions as calculated by the respective machines was compared for all interventions and for the respective subtypes and machines. The BMI dependency was calculated separately for both machines for all interventions by subdividing the patients into 6 BMI classes defined by the WHO. RESULTS: The average DAP for all diagnostic interventions was 1958.9 cGy×cm2 (t = 384.6 s, n = 7.85 series) for the II and 2927.4 cGy×cm2 (t = 267.4 s, n = 7.02 series) for the FPD. Group-dependent differences ranged between + 21 and + 252 % when using the FPD system. After time standardization, the respective increases were found to be 120 % for the FPD system. The DAPs increased considerably in patients with higher BMIs (766.7 cGy × cm2 - 6892.6 cGy × cm2, II machine, 950.5 cGy × cm2 - 12 487.7 cGy × cm2, FPD machine) with a greater DAP gain seen for the FPD. The average duration of the interventions was higher using the II machine. CONCLUSION: The use of an FPD system led to higher DAP values compared to the II system in diagnostic angiographic procedures. In addition, increased BMI values led to higher DAPs, especially for the FPD machine. However, the average fluoroscopy times were shorter.

Detection of artificial demineralization bordering different types of laminate veneers using visual inspection and storage phosphor radiography.

OBJECTIVE: The objective of this study is to compare the diagnostic accuracy of visual inspection (VI) and storage phosphor plate (SPP) radiography for the detection of artificial demineralization bordering different laminate veneers. MATERIALS AND METHODS: Twenty human maxillary canine teeth were prepared. All-ceramic (A) and hybrid ceramic (H) laminate veneers were fabricated and luted. Veneered teeth were covered except for a circular window on the proximal surface bordering restorations. Teeth were kept in acetic acid buffer to create demineralization and imaged with a SPP system. Ten observers evaluated all teeth first visually then with SPP images for the presence/absence of demineralization. Teeth were examined using scanning electron microscopy (SEM) as well. The accuracy was expressed as the area under the ROC curves (A(z)). Pair-wise comparisons were performed using two-way ANOVA and post hoc t test (p = 0.05). Fleiss kappa (κ) was used for agreement. RESULTS: SPP radiography was better than the VI for both veneers (p = 0.004). The A(z)s of two veneers were different for both VI (p < 0.005) and SPP (p < 0.005). SEM evaluation revealed lesions confined to enamel. κ was fair for H, and fair to moderate for A. Agreement was higher for the radiographic evaluation for both veneers. CONCLUSION: Enamel demineralizations bordering hybrid and ceramic laminate veneers can be detected better with SPP radiography than VI and detectability was better for all-ceramic veneers than the hybrid ceramic ones. CLINICAL RELEVANCE: Early detection of enamel demineralizations bordering laminate veneers would result in time-saving and less-invasive treatment methods; therefore, SPP radiography may be recommended in clinically suspicious cases since it provides better diagnostic accuracy.

Accuracy of landmark identification on postero-anterior cephalograms.

OBJECTIVES: The aim of this study was to examine accuracy in landmark identification on digital postero-anterior cephalograms, (PAC) assessing the intra-observer and the inter-observer repeatability in determining these landmarks. MATERIALS AND METHODS: Twenty postero-anterior digital cephalometric radiographs were randomly selected from data files of patients aged between 11 to 15 years and were used in this study. Thirty-four commonly used PAC landmarks were included in this investigation and each observer performed the determination of all landmarks on every PAC cephalograms twice (T1 and T2). Mean positions located by the three observers in the first recording session both on the x and y axes, were calculated and defined as the "best estimate" for every landmarks. Systematic differences between the two records at T1 and T2 of the same observer were evaluated using the paired t-test with P<0.05. In order to test the hypothesis of equal mean of the vectors of differences to the "best estimate" for the three raters, a one-way ANOVA test was performed. RESULTS: Most landmarks showed a good reproducibility between the two recording sessions, except for some landmarks located in the zygomatic arch, mandible and dentition. As regards inter-observer reliability, there were statistically significant differences (P<0.05) in both x and y axis. CONCLUSIONS: Each landmark has its own margin of error and there is a clear difference in the localization accuracy between the x and y coordinates. Since condylar points (CDr-CDl), coronoid points (CORr-CORl) and mental foramen points (MFr-MFl) showed to have a questionable localization accuracy, PAC cannot be strictly recommended for accurate evaluation of any asymmetry. Some dental landmarks seem to be poorly reproducible; therefore the usefulness of postero-anterior cephalometric analysis to evaluate dental discrepancies or maxillo-mandibular molar relationship is questioned.

Radiation exposure to operating staff during rotational flat-panel angiography and C-arm cone beam computed tomography (CT) applications.

PURPOSE: To evaluate the radiation exposure for operating personnel associated with rotational flat-panel angiography and C-arm cone beam CT. MATERIALS AND METHODS: Using a dedicated angiography-suite, 2D and 3D examinations of the liver were performed on a phantom to generate scattered radiation. Exposure was measured with a dosimeter at predefined heights (eye, thyroid, breast, gonads and knee) at the physician's location. Analysis included 3D procedures with a field of view (FOV) of 24 cm × 18 cm (8s/rotation, 20s/rotation and 5s/2 rotations), and 47 cm×18 cm (16s/2 rotations) and standard 2D angiography (10s, FOV 24 cm×18 cm). RESULTS: Measurements showed the highest radiation dose at the eye and thyroid level. In comparison to 2D-DSA (3.9 µSv eye-exposure), the 3D procedures caused an increased radiation exposure both in standard FOV (8s/rotation: 28.0 µSv, 20s/rotation: 79.3 µSv, 5s/2 rotations: 32.5 µSv) and large FOV (37.6 µSv). Proportional distributions were measured for the residual heights. With the use of lead glass, irradiation of the eye lens was reduced to 0.2 µSv (2D DSA) and 10.6 µSv (3D technique with 20s/rotation). CONCLUSION: Rotational flat-panel angiography and C-arm cone beam applications significantly increase radiation exposure to the attending operator in comparison to 2D angiography. Our study indicates that the physician should wear protective devices and leave the examination room when performing 3D examinations.

Comparison between differently priced devices for digital capture of X-ray films using computed tomography as a gold standard: a multireader-multicase receiver operating characteristic curve study.

OBJECTIVE: Film digitizers are a specialized technology that is available for scanning X-ray radiographs; however, their cost makes them unaffordable for developing countries. Thus, less expensive alternatives are used. The purpose of this study was to compare three devices for digital capture of X-ray films: a film digitizer (US $15,000), a flatbed scanner (US $1800), and a 10-megapixel digital camera (US $450), in terms of diagnostic accuracy, defined as the area under the receiver operating characteristic curves and computed tomography as the gold standard. MATERIALS AND METHODS: The sample included 136 chest X-ray cases with computed tomography confirmation of the presence or absence of pneumothorax, interstitial opacities, or nodules. The readers were six radiologists who made observations of eight variables for each digital capture of the X-ray films: three main variables to determine the accuracy in the detection of the above-mentioned pathologies, four secondary variables to categorize other pathological classifications, and one variable regarding digital image quality. RESULTS: The receiver operating characteristic curves for each device and pathology were very similar. For the main variables, there was no significant statistical difference in diagnostic accuracy between the devices. For the secondary variables, >84% of cases were correctly classified, even those that were classified with the lowest image quality. High accuracy was determined for the three main variables (0.75 to 0.96), indicating good performance for all tested devices, despite their very different prices. CONCLUSIONS: Choosing a device for a teleradiology service should involve additional factors, such as capture time, maintenance concerns, and training requirements.

Does a flat panel detector reduce the patient radiation dose in interventional cardiology?

An internal audit has been performed to evaluate the patient radiation dose in the clinical use of X-ray cardiac flat panel detector (FPD) systems. Fluoroscopy and image acquisition (cine mode) programs are optimised for low-dose settings. The diagnostic and therapeutic interventional cardiac procedures are performed at 6 pulse s(-1) for fluoroscopy and 15 frames s(-1) for image acquisition. The FPD entrance dose is configured for 29 nGy pulse(-1) in the fluoroscopy mode and 0.10 microGy frame(-1) in the cine mode. From the data collected, the following local reference levels for coronary angiography and angioplasty have been obtained: kerma-area products 23 and 44 Gy cm(2), cumulative doses 376 and 776 mGy, fluoroscopy times 5 and 15.5 min and cine images 617 and 1163 images.

Neuroradiologic applications with routine C-arm flat panel detector CT: evaluation of patient dose measurements.

BACKGROUND AND PURPOSE: Since the introduction of flat panel detector-equipped C-arms, the use of flat panel detector CT (FPCT) in the neuroradiologic angiography suite has become more frequent. This examination implicates its own specific radiation exposure. We used the CT dose index (CTDI) concept and adapted it to the special FPCT geometry to provide a consistent comparison with multisection head CT (cCT). MATERIALS AND METHODS: Exposure data obtained for routine scanning during a period of 1 year were used to assess a specific dose of a total of 217 rotational scans performed in 105 patients. One hundred seventy-two scans were 3D digital subtraction angiography (DSA) scans. There were 45 scans that were performed to achieve high-quality, soft-tissue resolution. Dose measurements in cylindrical polymethylmethacrylate (PMMA) phantoms were used to determine the CTDI value and to compare it with the reference values for cCT. In addition, the dose-area product (DAP) was registered and correlated with the CTDI and corresponding dose-length product (DLP) values. Exposure data and dose values were compared with cCT. RESULTS: Mean-weighted CTDI value of 3D-DSA was approximately 9 mGy per scan. High-quality, soft-tissue resolution FPCT scans, comparable with cCT, revealed a mean dose value of 75 mGy (reference value for cCT, CTDI(w) approximately 60 mGy). CONCLUSION: The high-speed scans used for 3D-DSA revealed a significantly lower CTDI(w) and DLP compared with clinical CT. The high-quality FPCT protocol resulted in a higher dose and should therefore be limited to acute cases, when patient transfer to a CT scanner is considered to be a disadvantage for patient management.

Imaging the neonate in the incubator: an investigation of the technical, radiological and nursing issues.

Modern neonatal incubators incorporate an X-ray tray device into the mattress support structure to facilitate patient examination with minimal disturbance and distress. However, the usual method of examination is to place the image plate directly underneath the baby. Users often cite radiological reasons for not using X-ray trays but modern quantitative evidence is lacking. This work looks at the technical and clinical aspects of imaging neonates in incubators and the impact that these may have in determining the imaging protocol. A number of hospitals were surveyed to determine their current method of examination and the reasons for their preference. Experimental measurements of the radiological impact of using (or not using) the X-ray tray were performed for a range of neonatal incubators. The average dose to the image plate was 5.9 microGy (range 5.4-6.4 microGy) for the "plate on mattress" method and 3.0 microGy (2.0-3.8 microGy) when using the tray--a 49% reduction owing to the mattress support materials. However, when using a computed radiography (CR) imaging system, the image quality differences were marginal. Survey results indicated that nurses preferred to use the tray but that radiographers were reluctant. We conclude that incubator manufacturers could do much to improve the radiological performance of their equipment and we offer recommendations. We also conclude that, with appropriate nurse and radiographer training and the advent of CR imaging systems, use of X-ray tray facilities may optimize imaging of the neonate in the incubator.

[Elastic stable intramedullary nailing (ESIN) in pediatric forearm shaft fractures: intraoperative image intensifier times]. / Elastisch stabile intramedulläre Nagelung (ESIN) von Unterarmschaftfrakturen im Wachstumsalter: Intraoperative Bildwandlerzeiten.

AIM: Elastic stable intramedullary nailing (ESIN)is the therapy of choice in pediatric forearm shaft fractures. It requires increased intraoperative image intensifier times and radiation load. METHOD: We performed a retrospective analysis of 78 operative procedures from a five-year period. In 16 cases the image intensifier times of the distinct steps of the operation were investigated prospectively. RESULTS: Average duration of the surgical procedure was 36.9 (18-144) minutes. Average radiation time was 59.5 (8-222) seconds. In educational operations, the duration of surgery was significantly longer than in procedures performed by experienced surgeons, but radiation times only were increased tendentially. In those procedures investigated prospectively, 53.1% of the image intensifier time was used for fracture passage. CONCLUSION: In ESIN of forearm shaft fractures,intraoperative image intensifier times of less than 2 minutes can be expected. Low intraoperative radiation times are a mark of quality. They serve for radiation protection of the patients, surgeons and OT staff.

Transition from screen-film to digital radiography: evolution of patient radiation doses at projection radiography.

PURPOSE: To retrospectively evaluate patient radiation doses in projection radiography after the transition to computed radiography (CR) in the authors' hospital. MATERIALS AND METHODS: The hospital's ethical committee approved the study and waived informed consent. In 2001, a dose reduction initiative was implemented, which involved collecting radiographic parameters, calculating patient entrance doses, and monitoring changes with an online computer, and a training program for radiographers was conducted. A database with 204 660 patient dose values was used to compute changes in patient doses over time. Sample sizes ranged from 1800 to 23 000 examinations. Doses were compared with European and American reference values. Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis. RESULTS: Median values for patient entrance doses increased 40%-103% after implementation of CR. Initial increases were corrected during the 1st year, and additional dose decreases were achieved after the dose reduction initiative was launched. At present, doses range between 15% and 38% of the European diagnostic reference levels established for screen-film radiography and between 28% and 41% of the reference values recommended by the American Association of Physicists in Medicine, representing an effective 20%-50% reduction in the initial values for CR. CONCLUSION: Though patient doses can increase considerably during the transition from conventional screen-film radiography to CR, dose management programs, including specific training of radiographers and patient dose audits, allow for reductions of the previous values.