Evaluation of Intra-articular Fracture Extension After Gunshot Wounds to the Lower Extremity: Plain Radiographs Versus Computer Tomography.

OBJECTIVE: This study was to compare the use of computer tomography with plain radiographs for the evaluation of intra-articular extension of long bone fractures in the lower extremity after low-energy gunshot wounds. DESIGN: Retrospective chart and radiographic review. SETTING: Level 1 Trauma Center. PATIENTS/PARTICIPANTS: Data were collected from a single institution from 2000 to 2014. Inclusion criteria consisted of patients greater than 17 years of age, low-velocity gunshot injuries causing fracture of the femur or tibia, plain radiographs with adequate films, and computed tomography (CT) imaging of the fracture. This consisted of 133 patients with 140 fractures. INTERVENTION: Intra-articular fracture extension was evaluated on initial plain radiographs and CTs. MAIN OUTCOME MEASURES: Comparison of "gold standard" CT with all reviewers' evaluation of plain radiographs. RESULTS: There were 140 total fractures; 108 were femoral fractures and 32 were tibial fractures. By comparing plain radiographs with the gold standard CT, the reviewers demonstrated correct diagnosis in 85% of intra-articular fractures and 96% of non-intra-articular fractures. In addition, the reviewers accurately diagnosed 70.8% of intra-articular extensions in the diaphysis and 70.5% in the metaphysis. The sensitivity and specificity for plain radiographs were 85.3% and 96.0%, respectively, for all locations. Metaphyseal and diaphyseal fractures demonstrated the poorest sensitivity at 80.7% and 82.1%, respectively. CONCLUSIONS: Low-energy gunshot wounds with fractures in the diaphyseal of the distal femur and all metaphyseal fractures warrant CT evaluation to better examine for intra-articular fracture extension. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

[Conventional X-Rays of Ankle Joint Fractures in Older Patients are Not Always Predictive]. / Einschränkungen der Aussagekraft des konventionellen Röntgenbilds bei Sprunggelenksfrakturen im Alter.

Background: Ankle fractures are extremely common in the elderly, with an incidence of up to 39 fractures per 100,000 persons per year. We found a discrepancy between intraoperative findings and preoperative X-ray findings. It was suggested that many relevant lesions of the ankle joint in the elderly cannot be detected with plain X-rays. Methods: Complete data sets and preoperative X-rays of 84 patients aged above 60 years with ankle fractures were analysed retrospectively. There were 59 women and 25 men, with a mean age of 69.9 years. Operation reports and preoperative X-rays were analysed with respect to four relevant lesions: multifragmentary fracture pattern of the lateral malleolus, involvement of the medial malleolus, posterior malleolar fractures and bony avulsion of anterior syndesmosis. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy and prevalence were calculated. Results: The prevalence of specific ankle lesions in the analyzed cohort was 24 % for the multifragmentary fracture pattern of the lateral malleolus, 38 % for fractures of the medial malleolus, 25 % for posterior malleolar fractures and 22.6 % for bony avulsions of the anterior syndesmosis. Multifragmentary fracture patterns of the lateral malleolus (sensitivity 0 %) and bony avulsions of the anterior syndesmosis (sensitivity 5 %) could not be detected in plain X-rays of the ankle joint at all. Fractures of the medial malleolus and involvement of the dorsal tibial facet were detected with a sensitivity of 96.8 % and 76.2 %, respectively, and specificity of 100 % in both cases. Conclusions: This study confirms that complex fracture patterns, such as multifragmentary involvement of the lateral malleolus, additional fracture of the medial malleolus, involvement of the dorsal tibial facet or bony avulsion of the anterior syndesmosis are common in ankle fractures of the elderly. Therefore, CT scans should be routinely considered for primary diagnosis, in addition to plain X-rays.

Screening Mammography Efficacy: A Comparison Between Screen-Film, Computed Radiography and Digital Mammography in Taiwan.

Breast cancer screening has been proven effective in Western countries, and our National Health Bureau also started to offer free screening mammography for women aged between 50 and 69, since July 2004. This study aims to compare the efficacy between distinctive mammography screening modalities. Prompting the assessment of digital screening in the radiological sciences, we provide insight into the practical informatics application of such tools.

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.

Diagnostic accuracy of cone beam computed tomography compared with intraoral radiography for the detection of noncavitated occlusal carious lesions.

The aim of this study was to evaluate the accuracy of cone beam computed tomography (CBCT) in the detection of noncavitated occlusal caries lesions and to compare this accuracy with that observed with conventional radiographs. 135 human teeth, 67 premolars and 68 molars with macroscopically intact occlusal surfaces, were examined by two independent observers using the CBCT system: NewTom 3G (Quantitative Radiology) and intraoral conventional film (Kodak Insight). The true lesion diagnosis was established by histological examination. The detection methods were compared by means of sensitivity, specificity, predictive values and accuracy. To assess intra- and interobserver agreement, weighted kappa coefficients were computed. Analyses were performed separately for caries reaching into dentin and for all noncavitated lesions. For the detection of occlusal lesions extending into dentin, sensitivity values were lower for film (0.45) when compared with CBCT (0.51), but the differences were not statistically significant (p > 0.19). For all occlusal lesions sensitivity values were 0.32 and 0.22, respectively, for CBCT and film. The specificity scores were high for both modalities. Interobserver agreement amounted to 0.93 for the CBCT system and to 0.87 for film. It was concluded that the use of the 9-inch field of view NewTom CBCT unit for the diagnosis of noncavitated occlusal caries cannot be recommended.

How do radiologists evaluate osteonecrosis?

OBJECTIVES: Management of patients with osteonecrosis of the hip remains controversial and challenging. Because the prognosis and treatment are determined in large part by the stage and extent of the disease, it is important to use a reliable and efficient method for evaluation and staging. The objective of this study was to determine how musculoskeletal (MSK) radiologists evaluate osteonecrosis and whether this evaluation is adequate. MATERIALS AND METHODS: A 12-part questionnaire was designed to determine how MSK radiologists evaluate patients with osteonecrosis of the femoral head (ONFH). This was sent to 888 members of the Society of Skeletal Radiology. RESULTS: One hundred and twenty-one members responded to essentially all questions. Patients were evaluated using plain radiographs and MRI. All agreed that it is clinically important to determine the extent of necrosis and joint involvement, and 115 (95 %) stated that this should be part of the radiologists' evaluation. However, only 55 (46 %) said that in practice they used a specific system of classification, and most of these used the Ficat and Arlet classification, which does not indicate the extent of involvement. One hundred and seven (88 %) respondents included a simple visual estimate of the extent of involvement, and a small number added a specific measurement of lesion size. The majority indicated that they were infrequently consulted about which imaging studies should be obtained. CONCLUSIONS: Although radiologists recognize the clinical importance of determining the extent of necrosis and joint involvement in patients with ONFH, in practice the methods used to evaluate these patients often do not accomplish this satisfactorily. The use of an effective classification, which includes both stage and extent of involvement, should be stressed, as it will lead to improved treatment of patients with ON. Physicians who order imaging studies for patients with ON should be encouraged to consult routinely with their radiology colleagues regarding which studies to request, as well as on the interpretation of these studies.

Diagnostic errors in interpretation of pediatric musculoskeletal radiographs at common injury sites.

BACKGROUND: Extremity pain represents one of the most common reasons for obtaining conventional radiographs in childhood. Despite the frequency of these examinations little is known about the incidence of diagnostic errors by interpreting pediatric radiologists. OBJECTIVE: The purpose of this study was to develop a standard error rate of pediatric radiologists by double-reading of extremity radiographs (elbow, wrists, knees and ankles) in children presenting with a history of trauma or pain. MATERIALS AND METHODS: During a 6-month period all major extremity radiographs (excluding digits) obtained at a large pediatric referral hospital for evaluation of pain or trauma were reviewed by two senior pediatric radiologists and compared to the official interpretation. All radiographs were interpreted initially by a board-certified pediatric radiologist with a Certificate of Added Qualification (CAQ). We reviewed 3,865 radiographic series in children and young adults 2-20 years of age. We tabulated misses and overcalls. We did not assess the clinical significance of the errors. RESULTS: There were 61 miss errors and 44 overcalls in 1,235 abnormal cases and 2,630 normal cases, for a 1.6% miss rate and a 1.1% overcall rate. Misses and overcalls were most common in the ankle. CONCLUSION: Interpretive errors by pediatric radiologists reviewing certain musculoskeletal radiographs are relatively infrequent. Diagnostic errors in the form of a miss or overcall occurred in 2.7% of the radiographs.

The influence of metallic posts in the detection of vertical root fractures using different imaging examinations.

OBJECTIVES: To assess the influence of metallic posts in the detection of simulated vertical root fractures (VRFs) using the following imaging examinations: 2 cone beam CT (CBCT) systems [CBCT1: NewTom(®) 3G (QR Srl, Verona, Italy) and CBCT2: i-CAT Next Generation(®) (Imaging Sciences International, Hatfield, PA)] and film and digital radiographs. Additionally, the influence of the orientation of the fracture line in the detection of VRFs was evaluated. METHODS: 100, human, single-rooted endodontically treated premolars were divided into 5 groups (Group 1: with posts and buccolingual VRFs, Group 2: with posts and mesiodistal VRFs, Group 3: without posts and with buccolingual VRFs, Group 4: without posts and with mesiodistal VRFs, and Group 5: with posts and without VRFs). The premolars were placed in human mandibles and imaged using the four examination modalities. The sensitivity and the specificity of each examination in the experimental groups were calculated. The data were analysed using Student's t-test. RESULTS: The presence of metallic posts reduced the sensitivity of the CBCT1 system (p = 0.0244). Digital radiographs and the CBCT1 and CBCT2 systems had a higher sensitivity in detecting buccolingual fractures in teeth with posts, whereas film and digital radiographs had a higher sensitivity in detecting buccolingual fractures in teeth without posts (p < 0.05). The CBCT1 examination demonstrated the lowest specificity (p < 0.05). CONCLUSIONS: The presence of metallic posts did not influence the sensitivity of most of the examinations, excluding the CBCT1 system. The fracture line orientation may influence VRF detection.

The (f)utility of flexion-extension C-spine films in the setting of trauma.

BACKGROUND: Flexion-extension radiographs are often used to assess for removal of the cervical collar in the setting of trauma. The objective of this study was to evaluate their adequacy. We hypothesized that a significant proportion is inadequate. METHODS: This was a retrospective review of C-spine clearance at a level 1 trauma center. A trauma-trained radiologist interpreted all flexion-extension radiographs for adequacy. Studies performed within 7 days of injury were considered acute. RESULTS: Three hundred fifty-five flexion-extension radiographs were examined. Ninety-five percent% of these studies were inadequate (51% because of the inability to visualize the top of T1, whereas 44% had less than 30° of angulation from neutral). Two hundred ten studies were performed acutely; of these, 97% were inadequate. When performed 7 days or longer from injury, 91% were inadequate. CONCLUSIONS: Injury to the C-spine may harbor significant consequences; therefore, its proper evaluation is critical. The majority of flexion-extension films are inadequate. As such, they should not be included in the algorithm for removal of the cervical collar. If used, adequacy must be verified and supplemental radiographic studies obtained as indicated.

Dental radiography in New Zealand: digital versus film.

UNLABELLED: Digital x-ray systems offer advantages over conventional film systems, yet many dentists have not adopted digital technology. OBJECTIVES: To assess New Zealand dental practitioners' use of--and preferences for--dental radiography systems. DESIGN: Cross-sectional survey. SETTING: General and specialist dental practice. PARTICIPANTS AND METHODS: Postal questionnaire survey of a sample of 770 dentists (520 randomly selected general dental practitioners and all 250 specialists) listed in the 2012 NZ Dental Council Register. MAIN OUTCOME MEASURES: Type of radiography systems used by dentists. Dentists' experiences and opinions of conventional film and digital radiography. RESULTS: The participation rate was 55.2%. Digital radiography systems were used by 58.0% of participating dentists, most commonly among those aged 31-40 years. Users of digital radiography tended to report greater satisfaction with their radiography systems than users conventional films. Two-thirds of film users were interested in switching to digital radiography in the near future. Reasons given by conventional film users for not using digital radiography included cost, difficulty in integrating with other software systems, concern about potential technical errors, and the size and nature of the intra-oral sensors. CONCLUSION: Many dental practitioners have still not adopted digital radiography, yet its users are more satisfied with their radiography systems than are conventional film users. The latter may find changing to a digital system to be satisfying and rewarding.

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.

Comparison of diagnostic performance on approximal caries detection among Swedish and Chinese senior dental students using analogue and digital radiographs.

UNLABELLED: The objective was to investigate diagnostic performance on approximal caries detection among Swedish and Chinese dental students using analogue and digital radiographs in vitro. Additionally, to compare the diagnostic accuracy of two image modalities for approximal caries detection. 46 extracted premolars and molars were mounted in blocks and exposed with two intra-oral systems, one CCD based digital radiographs and one with conventional films. 10 Swedish and 10 Chinese senior dental students diagnosed the approximal sites of the teeth exposed with the digital and analogue images. A 5 point diagnosis confidence scale was applied for caries registration for all the observers. Subsequently, the teeth were sectioned and histo-pathologically analyzed in order to obtain a gold standard. The data were analyzed in terms of receiver operating characteristic (ROC) curves for evaluation of diagnostic accuracy of the two radiographic methods and for the two groups of students for enamel and dentinal caries detection, respectively. The area under the ROC curve was significantly higher for dentinal caries detection compared with enamel caries detection for both Chinese and Swedish students and for both imaging modalities (p<0.001). The present results indicated that the students' ability for enamel caries detection on approximal surfaces was poor. Neither between the two student groups (p=0.15-0.64) nor between the two image modalities (p=0.34-0.91) a statistically significant difference in detecting approximal caries was found. CONCLUSIONS: The two different intra-oral x-ray systems were equally accurate. Chinese and Swedish students showed similar outcomes in their performance for approximal caries detection.

Evaluation of screening whole-breast sonography as a supplemental tool in conjunction with mammography in women with dense breasts.

OBJECTIVES: The purpose of this study was to evaluate the use and performance of supplemental screening whole-breast sonography in conjunction with mammography in asymptomatic women with dense breast tissue. METHODS: A total of 28,796 asymptomatic women underwent screening mammography. Among 20,864 women with dense breasts (72%), 8359 underwent additional sonography as part of their screening examinations. We classified women with mammographically dense breasts into mammography-only and mammography-plus-sonography groups. The reference standard was a combination of pathologic results and clinical follow-up at 2 years. We compared the recall rate, cancer detection yield, sensitivity, specificity, and positive predictive value in each group. RESULTS: Among the 20,864 women with dense breasts, 35 cancers were diagnosed, with a mean size of 13 mm. The cancer detection yield was 0.480 per 1000 women in the mammography-only group and increased to 2.871 in the mammography-plus-sonography group. Of 24 cancers detected in the mammography-plus-sonography group, the mean size was 11 mm, and the axillary lymph nodes were negative in 19 of 20. The sensitivity was significantly higher in the mammography-plus-sonography group than the mammography-only group (100% versus 54.55%; P = .002). The positive predictive values of sonographically prompted biopsy were 11.1% for the mammography-plus-sonography group and 50% for the mammography-only group. CONCLUSIONS: Supplemental screening whole-breast sonography increases the cancer detection yield by 2.391 cancers per 1000 women with dense breast tissue over that of mammography alone. It is beneficial for increased detection of breast cancers that are predominantly small and node negative; however, it also raises the number of false-positive results.

Evaluation of different techniques for CT radiation profile width measurement.

This work has been conducted to demonstrate a procedure for using a Konica Minolta computed radiography (CR) system for the measurement of computed tomography (CT) radiation profile width, and to compare this method with conventional and GAFCHROMIC XR-QA2 film measurements. The exposure and processing conditions of a Konica Minolta CR reader system were characterized to establish the relationship between exposure at the imaging plate (IP) and pixel value. A 6 cc ionization chamber was exposed at the isocenter of a CT scanner using 80 kVp, 0.4 sec with various mA settings. CR images were processed in fixed modes with various combinations of S and G values, establishing exposure and pixel value relationships. Appropriate exposure techniques and processing parameters were selected to avoid the saturation of the IP. Using the selected exposure and processing parameters, radiation profiles of various nominal collimation settings (40, 20, 10, and 5 mm) were acquired for measurement. Radiochromic film was characterized and utilized to compare with CR profiles and profiles obtained via conventional film. Appropriate exposures for both CR (80 kVp, large body filter, 4 and 8 mAs) and radiochromic films (120 kVp, large body filter, 300 mAs) were determined. Recommended CR processing settings (fixed mode with S = 5 and G= 1.81) were also determined. Compared to the conventional film results, the full width at half maximum (FWHM) results for CR agreed well within ± 10%, while radiochromic film results showed maximum deviations of about 5%. In conclusion, FWHM of CT radiation profiles can be conveniently and accurately measured using a Konica Minolta CR system or XR-QA2 film when appropriate exposure technique and processing parameters are used.

Can paper replace laser film to communicate the results of wrist radiographs in trauma cases? A reproducibility study of the reading of wrist trauma case radiographs on a PACS workstation, laser film, and paper.

The main goal of this study was to determine the reproducibility of the reading of wrist trauma case radiographs using three different media: laser film, a picture archiving and communication systems (PACS) workstation, and paper with an optimized layout. The study was conducted retrospectively in 200 consecutive patients consulting at the emergency department for wrist trauma and who underwent wrist X-ray investigation using a computed radiography system. There were 82 men and 118 women. The mean age was 48.3 years (16-95 years). Our institutional review board does not require patient approval or informed consent for retrospective review of case records. The readings were made by two independent readers who analyzed the 200 patient radiographs consecutively in one session for each type of media: paper, laser film, and on a PACS dual-screen workstation. The inter-reader agreements were substantial or almost perfect, with kappa values of 0.83 (0.76-0.90) for the PACS, 0.83 (0.76-0.90) for film, and 0.80 (0.72-0.87) for paper. The inter-technique agreement was almost perfect in all cases. There is a high interobserver agreement between PACS, laser film, and paper readings for wrist trauma cases. With a layout of one radiograph on each sheet, paper could replace laser films to communicate the results of wrist radiographs in trauma cases for outpatients.

Intramammary metastases: comparison of mammographic and ultrasound features.

PURPOSE: To describe the mammographical and ultrasound features of IM, and to compare radiological patterns of IM arising from different malignancies. MATERIALS AND METHODS: A retrospective search in the statistical database of our institution from January 2000 to December 2009 revealed 51 cases of intramammary metastases from solid malignancies. Additionally, a retrospective search in the Pubmed database was performed. Publications in the time interval from 1980 to 2010 were considered. After thorough analysis, 119 articles with 229 patients were involved in the study. Therefore, together with our cases our analysis comprises 280 patients. Mammographic and ultrasound findings of different IM were analyzed. RESULTS: The detected metastases showed two main radiological patterns: intramammary masses (81.5%) and architectural distortion (18.5%). Carcinomas of the stomach caused more frequently an architectural distortion, whereas other malignancies tended to present as intramammary masses. The size of the masses ranged from 2 to 104 mm. The largest lesions occurred in rhabdomyosarcoma, followed by hepatocellular carcinoma and squamous cell carcinomas of the head and neck region. The smallest lesions arose from malignancies of the thyroid gland carcinoma. Most IM showed circumscribed margins, while breast lesions in rhabdomyosarcoma were rather microlobulated. On ultrasound, IM from lung cancer were usually inhomogenously hypoechoic with circumscribed margins and showed posterior shadowing in almost 50% of the cases. Breast metastases from ovarian carcinoma had typically microlobulated margins and posterior enhancement. CONCLUSION: IM can present with a broad spectrum of radiological features. Their imaging findings vary depending on the primary tumor.

Root canal length determination by different methods in primary teeth: an in vivo study.

PURPOSE: To evaluate and compare the accuracy of root canal lengths (RCLs) in primary teeth using different clinical methods. METHODS: RCLs of 70 extracted human primary single-rooted teeth were estimated in vivo by a calibrated investigator using the electronic apex locator (EAL) method, radiovisiography (RVG), conventional radiography (X-ray), and tactile sensation method (TSM). The teeth were categorized into Group 1 (G1; teeth without physiological root resorption [PRR]); Group 2 (G2; teeth with one-fourth apical PRR); and Group 3 (G3; teeth with one-fourth to three-fourths lingual PRR). RCLs determined by various in vivo methods were compared with the ex vivo actual root canal length method (ARCL), as determined by stereo-microscope. Data obtained were compared using analysis of variance, Newman-Keuls test, and Student's test. RESULTS: In Groups 1 and 2, the mean RCL determined by EAL was closest to that of the gold standard ARCL, followed by RVG, X-ray, and TSM. In G3, the mean RCL determined by EAL was closest to ARCL, followed by TSM, RVG, and X-ray. CONCLUSION: A fifth-generation electronic apex locator was found to be useful in accurately determining root canal lengths of primary teeth with or without physiological root resorption.

Digital compared with screen-film mammography: performance measures in concurrent cohorts within an organized breast screening program.

PURPOSE: To evaluate the performance of digital direct radiography (DR) and computed radiography (CR) compared with that of screen-film mammography (SFM) in large concurrent cohorts. MATERIALS AND METHODS: This study was approved by the University of Toronto Research Ethics Board and did not require informed consent. Concurrent cohorts of women aged 50-74 years screened with DR (n = 220 520), CR (n = 64 210), or SFM (n = 403 688) between 2008 and 2009 were identified and followed for 12 months. Performance was compared between cohorts, with SFM as the referent cohort. Associations were examined by using mixed-effect logistic regression. RESULTS: The cancer detection rate was similar for DR (4.9 per 1000; 95% confidence interval [CI]: 4.7, 5.2) and SFM (4.8 per 1000; 95% CI: 4.7, 5.0); however, the rate was significantly lower for CR (3.4 per 1000; 95% CI: 3.0, 3.9) (odds ratio, 0.79; 95% CI: 0.68, 0.93). Recall rates were higher for DR (7.7%; 95% CI: 7.6%, 7.8%) and lower for CR (6.6%; 95% CI: 6.5%, 6.7%) than for SFM (7.4%; 95% CI: 7.3%, 7.5%). Positive predictive value was lower for CR (5.2%; 95% CI: 4.7%, 5.8%) than for SFM (6.6%; 95% CI: 6.4%, 6.8%); however, the adjusted odds were not significant. CONCLUSION: Although DR is equivalent to SFM for breast screening among women aged 50-74 years, the cancer detection rate was lower for CR. Screening programs should monitor the performance of CR separately and may consider informing women of the potentially lower cancer detection rates.

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.