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1.  A survey of digital radiography practice in four South African teaching hospitals: an illuminative study 
The purpose of this study was to assess radiographer familiarity and preferences with digital radiography in four teaching hospitals and thereafter make recommendations in line with the migration from screen film to digital radiography.
Materials and methods:
A questionnaire was designed to collect data from either qualified or student radiographers from four teaching hospitals. From the four teaching hospitals, there were a total of 205 potential respondents. Among other things, responses regarding experiences and preferences with digital radiography, quality control procedures, patient dose, advantages and disadvantages of digital radiography were sought. The information collected was based on self-reporting by the participants. The study is exploratory in nature and descriptive statistics were generated from the collected data using Microsoft Excel 2007 and StatsDirect software.
Sixty-three out of 205 (31%) radiographers from all the four radiology centers responded to the circulated questionnaire. Only 15% (8) of the qualified radiographers had 4 or more years of experience with digital radiography compared to 68% (36) for the same amount of experience with screen-film radiography. Sixty-one percent (38) of the participants had been exposed to digital radiography during their lectures while at university. A small proportion, 16% (10) of the respondents underwent formal training in quality control procedures on the digital X-ray units they were using. Slightly more than half (55%) of the participants felt it was easier for them to retake an image in digital radiography than in screen film radiography.
The results of this survey showed that the participants are familiar with digital radiography and have embraced this relatively new technology as shown by the fact that they can identify both its advantages and disadvantages as applied to clinical practice. However, there are minimal quality control procedures specific to digital radiography being undertaken as such there is need for formal education, continuing education and manufacturer training with respect to quality control as institutions make the transition from conventional screen film radiology to digital radiology.
PMCID: PMC3097796  PMID: 21611065
Digital radiography; radiography practice; quality control
2.  Photon-counting gamma camera based on columnar CsI(Tl) optically coupled to a back-illuminated CCD 
Proceedings of SPIE  2007;6510:65100N.
Recent advances have been made in a new class of CCD-based, single-photon-counting gamma-ray detectors which offer sub-100 μm intrinsic resolutions.1–7 These detectors show great promise in small-animal SPECT and molecular imaging and exist in a variety of configurations. Typically, a columnar CsI(Tl) scintillator or a radiography screen (Gd2O2S:Tb) is imaged onto the CCD. Gamma-ray interactions are seen as clusters of signal spread over multiple pixels. When the detector is operated in a charge-integration mode, signal spread across pixels results in spatial-resolution degradation. However, if the detector is operated in photon-counting mode, the gamma-ray interaction position can be estimated using either Anger (centroid) estimation or maximum-likelihood position estimation resulting in a substantial improvement in spatial resolution.2 Due to the low-light-level nature of the scintillation process, CCD-based gamma cameras implement an amplification stage in the CCD via electron multiplying (EMCCDs)8–10 or via an image intensifier prior to the optical path.1
We have applied ideas and techniques from previous systems to our high-resolution LumiSPECT detector.11, 12 LumiSPECT is a dual-modality optical/SPECT small-animal imaging system which was originally designed to operate in charge-integration mode. It employs a cryogenically cooled, high-quantum-efficiency, back-illuminated large-format CCD and operates in single-photon-counting mode without any intermediate amplification process. Operating in photon-counting mode, the detector has an intrinsic spatial resolution of 64 μm compared to 134 μm in integrating mode.
PMCID: PMC2947833  PMID: 20890397
Photon-Counting; EMCCD; molecular imaging; columnar CsI(Tl); SPECT; Bazooka SPECT detector
3.  Screening chest radiography: results from a Greek cross-sectional survey 
BMC Public Health  2006;6:113.
Public health authorities worldwide discourage the use of chest radiography as a screening modality, as the diagnostic performance of chest radiography does not justify its application for screening and may even be harmful, since people with false positive results may experience anxiety and concern. Despite the accumulated evidence, various reports suggest that primary care physicians throughout the world still prescribe chest radiography for screening. We therefore set out to index the use of chest radiography for screening purposes among the healthy adult population and to analyze its relationship with possible trigger factors.
The study was designed as a cross-sectional survey. Five thousand four hundred and ninety-nine healthy adults, coming from 26 Greek provinces were surveyed for screening practice habits in the nationwide anticancer study. Data were obtained for the use of screening chest radiography. Impact of age, gender, tobacco exposure, family history positive for malignancies and professional-risk for lung diseases was further analyzed.
we found that 20% (n = 1099) of the surveyed individuals underwent chest radiography for screening purposes for at least one time during the previous three years. Among those, 24% do so with a frequency equal or higher than once yearly, and 48% with a frequency equal or higher than every three years. Screening for chest radiography was more commonly adopted among males (OR 1.130, 95% CI 0.988–1.292), pensioners (OR 1.319, CI 1.093–1.593) and individuals with a positive family history for lung cancer (OR 1.251, CI 0.988–1.583). Multivariate analysis confirmed these results.
Despite formal recommendations, chest radiography for screening purposes was a common practice among the analyzed sample of Greek adults. This practice is of questionable value since the positive predictive value of chest radiography is low. The implementation of even a relatively inexpensive imaging study on a national scale would greatly burden health economics and the workload of radiology departments.
PMCID: PMC1513384  PMID: 16646992
4.  SCAR Radiologic Technologist Survey: Analysis of the Impact of Digital Technologies on Productivity  
Journal of Digital Imaging  2002;15(3):132-140.
As medical reimbursements continue to decline, increasing financial pressures are placed upon medical imaging providers. This burden is exacerbated by the existing radiologic technologist (RT) crisis, which has caused RT salaries to trend upward. One strategy to address these trends is employing technology to improve technologist productivity. While industry-wide RT productivity benchmarks have been established for film-based operation, little to date has been published in the medical literature regarding similar productivity measures for filmless operation using PACS. This study was undertaken to document the complex relationship between technologist productivity and implementation of digital radiography and digital information technologies, including PACS and hospital/radiology information systems (HIS/RIS). A nationwide survey was conducted with 112 participating institutions, in varying degrees of digital technology implementation. Technologist productivity was defined as the number of annual exams performed per technologist full-time equivalent (FTE). Productivity analyses were performed among the different demographic and technology profile groups, with a focus on general radiography, which accounts for 65-70% of imaging department volumes. When evaluating the relationship between technologist productivity and digital technology implementation, improved productivity measures were observed for institutions implementing HIS/RIS, modality worklist, and PACS. The timing of PACS implementation was found to have a significant effect on technologist productivity measures, with an initial 10.8% drop in productivity during the first year of PACS implementation, followed by a 27.8% increase in productivity beyond year one. This suggests there is a "PACS learning curve" phenomenon, which should be considered when institutions are planning for PACS implementation.
PMCID: PMC3613256  PMID: 12481227
5.  Depiction of Nidi and Fibrovascular Zones of Osteoid Osteomas Using Gamma-Correction Tc-99m HDP Pinhole Bone Scan and Conventional Radiograph, and Correlation with CT, MRI, and PVC Phantom Imaging 
For the precise imaging diagnosis of osteoid osteoma (OO), the identification of the nidus and fibrovascular zone (FVZ) is essential. However, the latter sign has received little attention because it is difficult to demonstrate. We applied the recently introduced gamma correction (GC) to depict the FVZ on pinhole bone scan (PBS), conventional radiography (CR), and computed tomography (CT). Non-gamma correction MRI was also analyzed for reference.
Ten patients with histologically proven diagnoses of OO were enrolled in this retrospective study. PBS, CR, and CT were processed by GC to demonstrate the nidi and FVZ as distinct yet integrating components of OO. PBS was performed using a 4-mm pinhole collimator 3 h after iv injection of 925 to 1,110 MBq (25 to 30 mCi) of Tc-99m HDP, and anteroposterior and mediolateral CR and transverse CT were taken according to the standard technique. MRI sequences included T1- and T2-weighted images. For gamma correction, we utilized the Photo Correction Wizard program of ACD Photo Editor v3.1. A team of three qualified nuclear physician-radiologists, two nuclear physicians, and one MRI specialist read bone scans, radiographs, and MRIs of OO according to each specialty, and orthopaedic aspects and histology were reviewed by one qualified orthopedic surgeon and two qualified pathologists, respectively. Each observer first read the images separately with basic information about the aim of the study given and then in concert. Interpretive disagreement was settled by discussion and consensus.
On pinhole scan, nidi were presented as areas of intense tracer uptake in all cases, and, importantly after GC, a thin ring-like zone with lower tracer uptake became visible in seven out of ten cases. GCCR also revealed a thin lucent zone that circumscribed the nidi in six out of ten cases and GCCT in two of four cases. MRI, without GC, presented nidi with high signal in the center and a thin ring-like zone with low signal in the periphery in five out of six cases. Ring-like zones were 1–2 mm in thickness and circumscribed the nidus as an integrated part and, hence, were morphologically interpreted as FVZ. Histologically, the presence of a variously mineralized FVZ was confirmed in four cases, but individual locus-by-locus image-histology correlation could not be accompolished because specimens were fragmentary. In the FVZ, tracer uptake was lower than in nidi, presumably reflecting that bone metabolism in the two parts differs as in their histology. Statistically, no significant correlation existed between the duration of symptoms and imaging demonstrability of the FVZ (Spearman’s test r = −0.057, p = 0.877), but parallelism existed in the demonstrability of the FVZ among GC PBS, CR, and CT, and non-correction MRI.
GC was useful to enhance the resolution of PBS, CR, and CT in OO so that both the nidi and FVZ were separately imaged. The use of CG PBS and CR in combination is recommended for the specific diagnosis of OO with information about bone metabolism and anatomical characteristics. PBS and CR are economical and widely available.
PMCID: PMC4042952  PMID: 24899974
Osteoid osteoma; Pinhole bone scan; Gamma correction
6.  Intrathoracic lipoma masquerading as subclavian artery trauma. 
A 58 year old man was admitted to the accident and emergency department following an industrial accident in which he sustained a three part fracture dislocation of his right humerus. Chest radiography revealed a large mass in the right upper hemithorax and, when the patient became hypotensive, an emergency thoracotomy was performed. The mass was found to be a massive intrathoracic lipoma. This case shows how preexisting intrathoracic lesions may be mistaken for subclavian or great vessel trauma following violent shoulder girdle injury. The differential diagnosis of traumatic and non-traumatic intrathoracic mass lesions in chest radiography should be considered carefully.
PMCID: PMC1342737  PMID: 8832354
7.  Surveillance for Radiation-Related Exposures Reported to the National Poison Data System 
To describe radiation-related exposures of potential public health significance reported to the National Poison Data System (NPDS).
For radiological incidents, collecting surveillance data can identify radiation-related public health significant incidents quickly and enable public health officials to describe the characteristics of the affected population and the magnitude of the health impact which in turn can inform public health decision-making. A survey administered by the Council of State and Territorial Epidemiologists (CSTE) to state health departments in 2010 assessed the extent of state-level planning for surveillance of radiation-related exposures and incidents: 70%–84% of states reported minimal or no planning completed. One data source for surveillance of radiological exposures and illnesses is regional poison centers (PCs), who receive information requests and reported exposures from healthcare providers and the public. Since 2010, the Centers for Disease Control and Prevention (CDC) and the American Association of Poison Control Centers (AAPCC) have conducted ongoing surveillance for exposures to radiation and radioactive materials reported from all 57 United States (US) PCs to NPDS, a web-based, national PC reporting database and surveillance system.
We collaborated with the American Association of Poison Control Centers (AAPCC), Poisindex® and Thomson Reuters Healthcare to develop an improved coding system for tracking radiation-related exposures reported to US PCs during 2011 and trained PC staff on its usage. We reviewed NPDS data from 1 September 2010 – 30 June 2012 for reported exposures to pharmaceutical or nonpharmaceutical radionuclides; ionizing radiation; radiological or nuclear weapons; or X-ray, alpha, beta, gamma, or neutron radiation. CDC medical toxicology and epidemiology staff reviewed each reported exposure to determine whether it was of potential public health concern (e.g. exposures associated with an ongoing public health emergency, several reported exposures clustered in space and time). When further information was needed to classify the potential public health importance of a call, CDC and AAPCC staff contacted the regional PC where each call originated. When exposures were spatially and temporally clustered, we reviewed news stories in the public media for evidence of an associated radiation incident.
Of 419 exposures reported during the study period, 25 were associated with a radiation-related incident. Of these, 4 were related to an exposure to x-ray radiation from an industrial radiography incident, 11 were related to a transportation accident involving potential contamination with radioactive material, and 10 were related to the Fukushima Daiichi Japan nuclear reactor disaster. Public health, hazardous materials, or hospital radiation safety staff were involved in responding to each of these events. We also identified 26 reported exposures associated with a regional radiation anti-terrorism exercise. The reported exposures were followed-up and removed from analysis once we determined they were part of the exercise. The remaining (n=368; 88%) were either requests for information, confirmed non-exposures, or exposures deemed unrelated or non-significant.
The capability to monitor self- or clinician-reported exposures to radiation and radioactive materials is available in NPDS for state and local public health use in collaboration with their regional PC and may improve public health capacity to identify and respond to radiological emergencies. Next steps include testing the system’s capability to accurately classify and rapidly respond to a cluster of calls to PCs reporting radiation exposures associated with a “dirty bomb” exercise during July, 2012.
PMCID: PMC3692946
Surveillance; Poison center; radiation
8.  Assessment of Coronary Artery Calcium Using Dual-Energy Subtraction Digital Radiography 
Journal of Digital Imaging  2011;25(1):129-136.
Cardiovascular disease is the leading cause of global mortality, yet its early detection remains a vexing problem of modern medicine. Although the computed tomography (CT) calcium score predicts cardiovascular risk, relatively high cost ($250–400) and radiation dose (1–3 mSv) limit its universal utility as a screening tool. Dual-energy digital subtraction radiography (DE; <$60, 0.07 mSv) enables detection of calcified structures with high sensitivity. In this pilot study, we examined DE radiography’s ability to quantify coronary artery calcification (CAC). We identified 25 patients who underwent non-contrast CT and DE chest imaging performed within 12 months using documented CAC as the major inclusion criteria. A DE calcium score was developed based on pixel intensity multiplied by the area of the calcified plaque. DE scores were plotted against CT scores. Subsequently, a validation cohort of 14 additional patients was independently evaluated to confirm the accuracy and precision of CAC quantification, yielding a total of 39 subjects. Among all subjects (n = 39), the DE score demonstrated a correlation coefficient of 0.87 (p < 0.0001) when compared with the CT score. For the 13 patients with CT scores of <400, the correlation coefficient was −0.26. For the 26 patients with CT scores of ≥400, the correlation coefficient yielded 0.86. This pilot study demonstrates the feasibility of DE radiography to identify patients at the highest cardiovascular risk. DE radiography’s accuracy at lower scores remains unclear. Further evaluation of DE radiography as an inexpensive and low-radiation imaging tool to diagnose cardiovascular disease appears warranted.
PMCID: PMC3264713  PMID: 21557030
Calcification detection; Cardiac imaging; Chest CT; Chest radiographs; Computed tomography; Coronary arteries; Coronary calcifications; Coronary disease; Digital radiography; Digital subtraction radiography; Dual-energy subtraction; Radiography; Dual-energy scanned projection; ROC-based analysis
9.  Reliability of Overcoverage Parameters With Varying Morphologic Pincer Features: Comparison of EOS® and Radiography 
Multiple radiographic parameters used for diagnosis and quantification of morphologic pincer features have emerged, but the degree to which pelvic tilt or rotation affects conventional radiography and EOS® is unknown.
We asked: (1) What is the reliability of EOS® and conventional radiography at increasing sizes of morphologic pincer features with varying degrees of tilt and rotation? (2) What is the effect of tilt and rotation on acetabular overcoverage measurements?
Using a dry cadaveric pelvis, AP conventional radiographs and EOS® images were taken at intervals of increasing modeled pincer size with 0° to 15° varying tilt and rotation. Lateral center-edge angle, Sharp angle, Tönnis angle, crossover sign, and retroversion index were measured on all images. Statistical analysis was conducted.
The intermodality intraclass correlation coefficients for conventional radiography and EOS® radiography across all pincer sizes, rotations, and tilts were excellent (0.93–0.98). Crossover sign was in perfect agreement in conventional radiography and EOS®. Rotation of the hip away from the beam source and/or increased anterior tilt falsely increased all overcoverage parameters except for Tönnis angle. Rotation away from the beam of 10°or greater or anterior tilt of 5° or greater produced a false-positive crossover sign.
EOS® radiography maintained excellent reliability in comparison to conventional radiography but both were equally vulnerable to the effects of tilt and rotation for quantification of hip parameters used in acetabular overcoverage assessment. A standardized pelvic radiograph ensuring that the pelvis is not excessively tilted or rotated should be used for assessing acetabular overcoverage parameters.
PMCID: PMC3705041  PMID: 23657877
10.  Results of Initial Low-Dose Computed Tomographic Screening for Lung Cancer 
The New England journal of medicine  2013;368(21):1980-1991.
Lung cancer is the largest contributor to mortality from cancer. The National Lung Screening Trial (NLST) showed that screening with low-dose helical computed tomography (CT) rather than with chest radiography reduced mortality from lung cancer. We describe the screening, diagnosis, and limited treatment results from the initial round of screening in the NLST to inform and improve lung-cancer– screening programs.
At 33 U.S. centers, from August 2002 through April 2004, we enrolled asymptomatic participants, 55 to 74 years of age, with a history of at least 30 pack-years of smoking. The participants were randomly assigned to undergo annual screening, with the use of either low-dose CT or chest radiography, for 3 years. Nodules or other suspicious findings were classified as positive results. This article reports findings from the initial screening examination.
A total of 53,439 eligible participants were randomly assigned to a study group (26,715 to low-dose CT and 26,724 to chest radiography); 26,309 participants (98.5%) and 26,035 (97.4%), respectively, underwent screening. A total of 7191 participants (27.3%) in the low-dose CT group and 2387 (9.2%) in the radiography group had a positive screening result; in the respective groups, 6369 participants (90.4%) and 2176 (92.7%) had at least one follow-up diagnostic procedure, including imaging in 5717 (81.1%) and 2010 (85.6%) and surgery in 297 (4.2%) and 121 (5.2%). Lung cancer was diagnosed in 292 participants (1.1%) in the low-dose CT group versus 190 (0.7%) in the radiography group (stage 1 in 158 vs. 70 participants and stage IIB to IV in 120 vs. 112). Sensitivity and specificity were 93.8% and 73.4% for low-dose CT and 73.5% and 91.3% for chest radiography, respectively.
The NLST initial screening results are consistent with the existing literature on screening by means of low-dose CT and chest radiography, suggesting that a reduction in mortality from lung cancer is achievable at U.S. screening centers that have staff experienced in chest CT. (Funded by the National Cancer Institute; NLST number, NCT00047385.)
PMCID: PMC3762603  PMID: 23697514
11.  Comparison of conventional radiography and MDCT in suspected scaphoid fractures 
World Journal of Radiology  2015;7(1):22-27.
AIM: To determine the diagnostic accuracy and radiation dose of conventional radiography and multidetector computed tomography (MDCT) in suspected scaphoid fractures.
METHODS: One hundred twenty-four consecutive patients were enrolled in our study who had suffered from a wrist trauma and showed typical clinical symptoms suspicious of an acute scaphoid fracture. All patients had initially undergone conventional radiography. Subsequent MDCT was performed within 10 d because of persisting clinical symptoms. Using the MDCT data as the reference standard, a fourfold table was used to classify the test results. The effective dose and impaired energy were assessed in order to compare the radiation burden of the two techniques. The Wilcoxon test was performed to compare the two diagnostic modalities.
RESULTS: Conventional radiography showed 34 acute fractures of the scaphoid in 124 patients (42.2%). Subsequent MDCT revealed a total of 42 scaphoid fractures. The sensitivity of conventional radiography for scaphoid fracture detection was 42.8% and its specificity was 80% resulting in an overall accuracy of 59.6%. Conventional radiography was significantly inferior to MDCT (P < 0.01) concerning scaphoid fracture detection. The mean effective dose of MDCT was 0.1 mSv compared to 0.002 mSv of conventional radiography.
CONCLUSION: Conventional radiography is insufficient for accurate scaphoid fracture detection. Regarding the almost negligible effective dose, MDCT should serve as the first imaging modality in wrist trauma.
PMCID: PMC4295175  PMID: 25628802
Musculoskeletal imaging; Scaphoid fracture; Multidetector computed tomography; Biplane radiography; Emergency radiology; Diagnostic accuracy; Wrist trauma; Dose calculation
12.  Accuracy of Digital Subtraction Radiography in Combination with a Contrast Media in Assessment of Proximal Caries Depth 
Background and aims
Radiography is used to diagnose the demineralization process and carious lesions; however, conventional radiography and direct digital images do not show these lesions when the amount of demineralization is less than 40%. Digital subtraction radiography has recently been used to improve the diagnostic quality of these le-sions. The purpose of this study was to compare the caries depth estimated by digital subtraction radiog-raphy in combination with barium sulfate in diag-nosing proximal dental caries with histopathologic evaluation.
Materials and methods
In this study 30 molars and premolars (24 demineralized lesions with cavity, 8 without cavity) were studied. Direct digital images were taken (kVp: 68, mA: 8; t: 0.12 for premolars and t: 0.16 for molars) whereas the position of X-ray tube and CCD receptor and teeth was fixed. To prepare the second images 135 gr/L barium sulfate was used. The images obtained with the same exposure and geometry and then subtracted. The depth of the lesions in direct digital and subtracted images were assessed and compared with the depth measured in histopathologic assessments.
The mean depths (± SD) of the lesions were 1.80 ± 0.77 mm in direct digital radiography, 2.32 ± 0.76 mm in subtracted images after barium sulfate treatment, and 2.51 ± 0.43 mm in histopathologic sections. The statistical difference between direct digital radiography and the other methods was significant (P < 0.05). However, the differences were not statistically significant between subtracted images and histopathologic sections. The average intra-class correlation coefficient was 0.7241 (CI: 95%).
The present study has demonstrated that digital subtraction radiography images have the potential to measure the depth of proximal caries with no significant difference with histopathologic evaluation.
PMCID: PMC3532727  PMID: 23277849
Barium sulfate; dental caries; digital subtraction radiography
13.  Is Immediate Imaging Important in Managing Low Back Pain? 
Journal of Athletic Training  2011;46(1):99-102.
Chou R, Fu R, Carrino JA, Deyo RA. Imaging strategies for low-back pain: systematic review and meta-analysis. Lancet. 2009;373(9662):463–472.
Clinical Questions:
In patients with low back pain (LBP) who do not have indications of a serious underlying condition, does routine, immediate lumbar imaging result in improved patient outcomes when compared with clinical care without immediate imaging?
Data Sources:
Studies were identified by searching MEDLINE (1966 through first week of August 2008) and the Cochrane Central Register of Controlled Trials (third quarter of 2008). The reference lists of identified studies were manually reviewed for additional citations. The search terms spine, low-back pain, diagnostic imaging, and randomized controlled trials were used in both databases. The complete search strategy was made available as an online supplement.
Study Selection:
The search criteria were applied to the articles obtained from the electronic searches and the subsequent manual searches with no language restrictions. This systematic review and meta-analysis included randomized, controlled trials that compared immediate, routine lumbar imaging (or routine provision of imaging findings) with usual clinical care without immediate lumbar imaging (or not routinely providing results of imaging) for LBP without indications of serious underlying conditions.
Data Extraction:
Data extraction and assessment of study quality were well described. The trials assessed one or more of the following outcomes: pain, function, mental health, quality of life, patient satisfaction, and overall patient-reported improvement. Two reviewers independently appraised citations considered potentially relevant, with disagreements between reviewers resolved by consensus. Two independent reviewers abstracted data from the trials and assessed quality with modified Cochrane Back Review Group criteria. The criterion for blinding of patients and providers was excluded because of lack of applicability to imaging studies. In addition, the criterion of co-intervention similarity was excluded because a potential effect of different imaging strategies is to alter subsequent treatment decisions. As a result of excluding these criteria, quality ratings were based on the remaining 8 criteria. The authors resolved disagreements about quality ratings through discussion and consensus. Trials that met 4 or more of the 8 criteria were classified as higher quality, whereas those that met 3 or fewer of the 8 criteria were classified as lower quality. In addition, the authors categorized duration of symptoms as acute (<4 weeks), subacute (4–12 weeks), or chronic (>12 weeks). The investigators also contacted the study authors for additional data if included outcomes were not published or if median (rather than mean) outcomes were reported. Statistical analysis was conducted on the primary outcomes of improvement in pain or function. Secondary outcomes of improvement in mental health, quality of life, patient satisfaction, and overall improvement were also analyzed. Outcomes were categorized as short term (≤3 months), long term (>6 months to ≤1 year), or extended (>1 year). For continuous outcomes, standardized mean differences (SMDs) of interventions for change between baseline and follow-up measurements were calculated. In studies reporting the same pain (visual analog scale [VAS] or Short Form-36 bodily pain score) or function (Roland-Morris Disability Questionnaire [RDQ]) outcomes, weighted mean differences (WMDs) were calculated. In all analyses, lower pain and function scores indicated better outcomes. For quality-of-life and mental health outcomes, higher scores indicated improved outcomes. All statistical analyses were performed with Stata 10.0. For outcomes in which SMDs were calculated, values of 0.2 to 0.5 were considered small, 0.5 to 0.8 were considered moderate, and values greater than 0.8 were considered large. For WMDs, mean improvements of 5 to 10 points on a 100-point scale (or equivalent) were considered small, 10-point to 20-point changes were considered moderate, and changes greater than 20 points were considered large. For the RDQ, mean improvements of 1 to 2 points were termed small, and improvements of 2 to 5 points were termed moderate.
Main Results:
The total number of citations identified using the search criteria was 479 articles and abstracts. Of these, 466 were excluded because either they were not randomized trials or they did not use imaging strategies for LBP. At this step, 13 articles were retrieved for further analysis. This analysis resulted in 3 additional articles being excluded (1 was not a randomized trial and the other 2 compared 2 imaging techniques rather than immediate imaging versus no imaging). The final step resulted in the inclusion of 6 trials reported in 10 publications for the meta-analysis. In the studies meeting the inclusion criteria, 4 assessed lumbar radiography and 2 assessed magnetic resonance imaging (MRI) or computed tomography (CT) scans. In these 6 trials, 1804 patients were randomly assigned to the intervention group. The duration of patient follow-up ranged from 3 weeks to 2 years. In addition, 1 trial excluded patients with sciatica or other radiculopathy symptoms, whereas another did not report the proportion of patients with these symptoms. In the other 4 studies, the proportion of patients with sciatica or radiculopathy ranged from 24% to 44%. Of the included trials, 3 compared immediate lumbar radiography with usual clinical care without immediate radiography, and a fourth study compared immediate lumbar radiography and a brief educational intervention with lumbar radiography if no improvement was seen by 3 weeks. The final 2 studies assessed advanced imaging modalities. Specifically, one group compared immediate MRI or CT with usual clinical care without advanced imaging in patients with primarily chronic LBP (82% with LBP for >3 months) who were referred to a surgeon. In the other advanced imaging study, all patients with LBP for <3 weeks underwent MRI and were then randomized to routine notification of results or to notification of results only if clinically indicated. With respect to study quality, 5 trials met at least 4 of the 8 predetermined quality criteria, leading to a classification of higher quality. In addition, 5 trials were included in the primary meta-analysis on pain or function improvement at 1 or more follow-up periods. With regard to short-term and long-term improvements in pain, no differences were noted between routine, immediate lumbar imaging and usual clinical care without immediate imaging (Table 1). In studies using the VAS pain score, the WMD (0.62, 95% confidence interval [CI]  =  0.03, 1.21) at short-term follow-up slightly favored no immediate imaging. No differences in outcome were seen in studies using the Short Form-36 bodily pain score. No improvements in function at short-term or long-term follow-up were noted between imaging strategies. Specifically, short-term function measured with the RDQ in 3 studies showed a WMD of 0.48 points (95% CI  =  −1.39, 2.35) between imaging strategies, whereas long-term function in 3 studies, also measured with the RDQ, showed a WMD of 0.33 points (95% CI  =  −0.65, 1.32). One included trial reported pain outcomes at extended (2-year) follow-up and found no differences between imaging strategies for pain (Short Form-36 bodily pain or Aberdeen pain score), with SMDs of −2.7 (95% CI  =  −6.17, 0.79) and −1.6 (−4.04, 0.84), respectively. The outcomes between immediate imaging and usual clinical care without immediate imaging did not differ for short-term follow-up in those studies reporting quality of life (SMD  =  −0.10, 95% CI  =  −0.53, 0.34), mental health (SMD  =  0.12, 95% CI  =  −0.37, 0.62), or overall improvement (mean risk ratio  =  0.83, 95% CI  =  0.65, 1.06). In those studies reporting long-term follow-up periods, similar results can be seen for quality of life (SMD  =  −0.15, 95% CI  =  −0.33, 0.04) and mental health (SMD  =  0.01, 95% CI  =  −0.32, 0.34). In the study reporting extended follow-up, immediate imaging was not better in terms of improving quality of life (SMD  =  0.02, 95% CI  =  −0.02, 0.07) or mental health (SMD  =  −1.50, 95% CI  =  −4.09, 1.09) when compared with usual clinical care without immediate imaging. In the included studies, no cases of cancer, infection, cauda equina syndrome, or other serious diagnoses were reported in patients randomly assigned to either imaging strategy.
Available evidence indicates that immediate, routine lumbar spine imaging in patients with LBP and without features indicating a serious underlying condition did not improve outcomes compared with usual clinical care without immediate imaging. Clinical care without immediate imaging seems to result in no increased odds of failure in identifying serious underlying conditions in patients without risk factors for these conditions. In addition to lacking clinical benefit, routine lumbar imaging is associated with radiation exposure (radiography and CT) and increased direct expenses for patients and may lead to unnecessary procedures. This evidence confirms that clinicians should refrain from routine, immediate lumbar imaging in primary care patients with nonspecific, acute or subacute LBP and no indications of underlying serious conditions. Specific consideration of patient expectations about the value of imaging was not addressed here; however, this aspect must be considered to avoid unnecessary imaging while also meeting patient expectations and increasing patient satisfaction.
PMCID: PMC3017496  PMID: 21214357
spine; assessment; outcomes
14.  Identification of Nasal Bone Fractures on Conventional Radiography and Facial CT: Comparison of the Diagnostic Accuracy in Different Imaging Modalities and Analysis of Interobserver Reliability 
Iranian Journal of Radiology  2013;10(3):140-147.
There has been no study to compare the diagnostic accuracy of an experienced radiologist with a trainee in nasal bone fracture.
To compare the diagnostic accuracy between conventional radiography and computed tomography (CT) for the identification of nasal bone fractures and to evaluate the interobserver reliability between a staff radiologist and a trainee.
Patients and Methods
A total of 108 patients who underwent conventional radiography and CT after acute nasal trauma were included in this retrospective study. Two readers, a staff radiologist and a second-year resident, independently assessed the results of the imaging studies.
Of the 108 patients, the presence of a nasal bone fracture was confirmed in 88 (81.5%) patients. The number of non-depressed fractures was higher than the number of depressed fractures. In nine (10.2%) patients, nasal bone fractures were only identified on conventional radiography, including three depressed and six non-depressed fractures. CT was more accurate as compared to conventional radiography for the identification of nasal bone fractures as determined by both readers (P <0.05), all diagnostic indices of an experienced radiologist were similar to or higher than those of a trainee, and κ statistics showed moderate agreement between the two diagnostic tools for both readers. There was no statistical difference in the assessment of interobserver reliability for both imaging modalities in the identification of nasal bone fractures.
For the identification of nasal bone fractures, CT was significantly superior to conventional radiography. Although a staff radiologist showed better values in the identification of nasal bone fracture and differentiation between depressed and non-depressed fractures than a trainee, there was no statistically significant difference in the interpretation of conventional radiography and CT between a radiologist and a trainee.
PMCID: PMC3857976  PMID: 24348599
Nasal Bone, Fractures, Bone; Radiography
15.  Accuracy of direct digital radiography for detecting occlusal caries in primary teeth compared with conventional radiography and visual inspection: an in vitro study 
Dentomaxillofacial Radiology  2010;39(6):362-367.
The diagnosis of caries lesions is still a matter of concern in dentistry. The diagnosis of dental caries by digital radiography has a number of advantages over conventional radiography; however, this method has not been explored fully in the field of paediatric dentistry. This in vitro research evaluated the accuracy of direct digital radiography compared with visual inspection and conventional radiography in the diagnosis of occlusal caries lesions in primary molars.
50 molars were selected and evaluated under standardized conditions by 2 previously calibrated examiners according to 3 diagnostic methods (visual inspection, conventional radiography and direct digital radiography). Direct digital radiographs were obtained with the Dixi3 system (Planmeca, Helsinki, Finland) and the conventional radiographs with InSight film (Kodak Eastman Co., Rochester, NY). The images were scored and a reference standard was obtained histologically. The interexaminer reliability was calculated using Cohen's kappa test and the specificity, sensitivity and accuracy of the methods were calculated.
Examiner reliability was good. For lesions limited to the enamel, visual inspection showed significantly higher sensitivity and accuracy than both radiographic methods, but no significant difference was found in specificity. For teeth with dentinal caries, no significant differences were found for any parameter when comparing visual and radiographic evaluation.
Although less accurate than the visual method for detecting caries lesions confined to the enamel, the direct digital radiographic method is as effective as conventional radiographic examination and visual inspection of primary teeth with occlusal caries when the dentine is involved.
PMCID: PMC3520238  PMID: 20729186
direct digital radiography; conventional radiography; dental caries; primary teeth
16.  Detection of dental root fractures by using cone-beam computed tomography 
Dentomaxillofacial Radiology  2011;40(5):290-298.
The purpose of this study was to compare the diagnostic accuracy of cone beam CT (CBCT) with that of conventional dental radiography in the detection of root fractures and to evaluate the influence of root canal fillings on root fracture detection.
We investigated 128 patients with clinically suspected root fractures in 135 teeth. These patients underwent conventional dental radiography, CBCT and eventually surgical exploration. Among the 135 teeth, 86 were non-endodontically treated teeth and 49 were endodontically treated teeth. Two oral radiologists independently analysed the dental radiographs and CBCT images of each patient and reached a consensus. The CBCT findings of root fractures were set as the detection of a separation of the adjacent root segments on at least two contiguous sections and on at least two of the three-dimensional (3D) planes.
Root fracture was intraoperatively detected in 95 of the 135 teeth. The sensitivity and specificity of root fractures diagnosed on the basis of the consensus between the 2 evaluators were 26.3% and 100%, respectively, for dental radiography and 89.5% and 97.5%, respectively, for CBCT. CBCT was significantly more accurate than dental radiography in detecting root fractures (P < 0.001). The sensitivity of CBCT was reduced in the presence of root canal fillings but its specificity remained unaffected. Both the sensitivity and specificity of dental radiography were not influenced by the presence of root canal fillings.
CBCT appears to be more accurate than conventional dental radiography in the detection of root fractures.
PMCID: PMC3520261  PMID: 21697154
cone-beam computed tomography; dental radiography; diagnosis; dental root fracture
17.  Usefulness of Ultrasound Examinations in the Diagnostics of Necrotizing Enterocolitis 
Necrotizing enterocolitis (NEC) is one of the most serious disorders of gastrointestinal tract during neonatal period. Early diagnosis and adequate treatment are essential in the presence of clinical suspicion of NEC. Plain abdominal radiography is currently the modality of choice for initial evaluation of gastrointestinal tract in neonates. However, when the diagnosis is uncertain, abdominal ultrasound with bowel assessment might be an important complementary examination. The aim of the study was to evaluate usefulness of ultrasound in the diagnosis of NEC and its value for implementation of proper treatment.
The data of nine neonates diagnosed with NEC, hospitalized at the Provincial Hospital No. 2 in Rzeszow in the period from September 2009 to April 2013 was retrospectively analyzed. Apart from abdominal radiography, abdominal ultrasound with bowel assessment was performed in all nine cases. Imaging findings, epidemiological data, coexisting risk factors and disease course were assessed.
Most children in the group were preterm neonates. Findings in plain abdominal radiography were normal or nonspecific. A wider spectrum of findings was demonstrated in all ultrasound examinations and intestinal pneumatosis, a pathognomonic sign for NEC, was more frequently noted than in plain abdominal x-ray. Most children were treated by surgical intervention with resection of necrotic bowel loops and in more than half of the cases location of changes identified during surgery was concordant with ultrasonographic findings.
Abdominal ultrasound examination might be helpful in the diagnosis of NEC, especially when plain abdominal radiography findings do not correlate with clinical symptoms. However, abdominal radiography is still considered the modality of choice. The range of morphological changes detectable on ultrasound examination is much wider than in plain abdominal radiography. Ultrasound examination allows for more accurate assessment of changes within intestines and adjacent tissues, which aids clinicians in making more accurate therapeutic decisions and implementing proper treatment.
PMCID: PMC4283822  PMID: 25574248
Diagnostic Imaging; Emergency Treatment; Neonatology
18.  Accuracy of the typical computed tomographic appearances of fibrosing alveolitis. 
Thorax  1993;48(4):334-338.
BACKGROUND--Open lung biopsy is often performed to confirm the diagnosis in patients with suspected fibrosing alveolitis. The superior sensitivity and specificity of high resolution computed tomography (CT) over chest radiography in various diffuse lung diseases suggest that the characteristic appearance of fibrosing alveolitis on high resolution CT might render biopsy confirmation unnecessary. METHODS--The chest radiographs and high resolution CT scans of 86 patients (41 with fibrosing alveolitis and 45 with various other diffuse lung diseases) were examined individually and independently by two observers. No clinical information was given and the observers gave a level of confidence when the diagnosis was thought to be fibrosing alveolitis. RESULTS--The observers correctly and confidently discriminated between fibrosing alveolitis and other diffuse lung diseases on high resolution CT with an accuracy of 88% and on chest radiography with an accuracy of 76%. The false negative rate for fibrosing alveolitis diminished from 29% on chest radiography to 11% on high resolution CT. The false positive rate on chest radiography was 19% and on high resolution CT 13%; the false positive diagnoses on CT were the result of a few conditions (extrinsic allergic alveolitis, sarcoidosis, cryptogenic organising pneumonia, and pulmonary eosinophilia) which mimicked some of the CT features of fibrosing alveolitis. The superficial similarity of the CT patterns of these conditions are discussed. CONCLUSIONS--High resolution CT is superior to chest radiography in establishing the diagnosis of fibrosing alveolitis and the typical CT appearances are virtually pathognomonic. The diagnostic advantages of CT over chest radiography should further reduce the need for open lung biopsy in this condition.
PMCID: PMC464428  PMID: 8135910
19.  The Accuracy of Digital Radiography in Orthopaedic Applications 
Recent advances in technology and the use of image archiving and communication systems (PACS) has led some institutions to abandon conventional plain film radiography and rely solely on digital computed radiography. The level of accuracy of digital radiography in measuring distances for orthopaedic applications is unclear.
Is it possible to accurately measure small distances using digital radiographs and PACS software?
Materials and Methods
A model for measuring articular step-off was created using a commercially produced radiographic phantom with predetermined markings at known distances. Radiographs were taken using both indirect and direct computed radiography systems, then uploaded to a PACS system. Eighteen observers measured the distance between standardized, preselected points on the radiographic phantom. The measured values were compared with the known values for each measurement.
The mean measured values differed by 0 and 0.1 mm (SD, 0.5 mm) for indirect and direct radiographs, respectively, when measuring short distances and 1.4 mm and 2.6 mm (SD, 1.0 mm) for indirect and direct radiographs, respectively, when measuring longer distances. The intraclass correlation coefficient (ICC) for interobserver reliability was 0.82 for indirect and 0.75 for direct digital radiography. The ICC for intraobserver reliability was 0.94 for indirect and 0.90 for direct digital radiography.
Although the mean measured values were very accurate (within 0.1 mm for a known distance of 3.2 mm), the SD of measurements (0.5 mm) could affect the interpretation of data, especially in clinical situations such as evaluating the quality of fracture reduction.
PMCID: PMC3094611  PMID: 20972654
20.  High Resolution Emission and Transmission Imaging Using the Same Detector 
We demonstrate the capability of one detector, the Micro-Angiographic Fluoroscope (MAF) detector, to image for two types of applications: nuclear medicine imaging and radiography. The MAF has 1024 × 1024 pixels with an effective pixel size of 35 microns and is capable of real-time imaging at 30 fps. It has a CCD camera coupled by a fiber-optic taper to a light image intensifier (LII) viewing a 300-micron thick CsI phosphor. The large variable gain of the LII provides quantum-limited operation with little additive instrumentation noise and enables operation in both energy-integrating (EI) and sensitive low-exposure single photon counting (SPC) modes. We used the EI mode to take a radiograph, and the SPC mode to image a custom phantom filled with 1 mCi of I-125. The phantom is made of hot rods with diameters ranging from 0.9 mm to 2.3 mm. A 1 mm diameter parallel hole, medium energy gamma camera collimator was placed between the phantom and the MAF and was moved multiple times at equal intervals in random directions to eliminate the grid pattern corresponding to the collimator septa. Data was acquired at 20 fps. Two algorithms to localize the events were used: 1) simple threshold and 2) a weighted centroid method. Although all the hot rods could be clearly identified, the image generated with the simple threshold method shows more blurring than that with the weighted centroid method. With the diffuse cluster of pixels from each single detection event localized to a single pixel, the weighted centroid method shows improved spatial resolution. A radiograph of the phantom was taken with the same MAF in EI mode without the collimator. It shows clear structural details of the rods. Compared to the radiograph, the sharpness of the emission image is limited by the collimator resolution and could be improved by optimized collimator design. This study demonstrated that the same MAF detector can be used in both radioisotope and x-ray imaging, combining the benefits of each.
PMCID: PMC3850766  PMID: 24319339
21.  Study on Construction of a Medical X-Ray Direct Digital Radiography System and Hybrid Preprocessing Methods 
We construct a medical X-ray direct digital radiography (DDR) system based on a CCD (charge-coupled devices) camera. For the original images captured from X-ray exposure, computer first executes image flat-field correction and image gamma correction, and then carries out image contrast enhancement. A hybrid image contrast enhancement algorithm which is based on sharp frequency localization-contourlet transform (SFL-CT) and contrast limited adaptive histogram equalization (CLAHE), is proposed and verified by the clinical DDR images. Experimental results show that, for the medical X-ray DDR images, the proposed comprehensive preprocessing algorithm can not only greatly enhance the contrast and detail information, but also improve the resolution capability of DDR system.
PMCID: PMC4074983  PMID: 25013452
22.  Developmental regulation of human gamma-globin genes in transgenic mice. 
Molecular and Cellular Biology  1993;13(12):7636-7644.
We report results showing that several gamma gene promoter elements participate in the developmental control of gamma-globin genes. Four gamma gene constructs with 5' truncated at -141, -201, -382, and -730 of the A gamma gene promoter linked to a micro locus control region (microLCR) cassette were used for production of transgenic mice and analysis of gamma gene expression during development. Mice carrying a microLCR -141 A gamma construct displayed downregulation of gamma gene expression in the adult stage of development, indicating that the proximal promoter contains elements participating in gamma gene silencing. Mice carrying a microLCR -201 A gamma or a microLCR -382 A gamma construct displayed high gamma gene expression in the fetal stage of development and complete loss of gamma gene downregulation in the adult stage, suggesting that the -141 to -201 gamma gene sequence contains elements which upregulate gamma gene expression and are dominant over the negative element 3' to -141. Extension of the promoter to -730 resulted in reappearance of gamma gene downregulation, suggesting that the -382 to -730 sequences contain an adult-stage-specific silencer. gamma gene expression in the microLCR -201 A gamma and the microLCR -382 A gamma transgenic mice was copy number dependent. All the microLCR -730 A gamma transgenic mice expressed gamma mRNA; however, gamma gene expression was copy number independent, indicating that levels of gamma gene expression were modulated by the surrounding chromatin. Our results suggest that multiple elements participate in gamma gene silencing. The findings in the microLCR-201 A gamma and microLCR -382 A gamma transgenic mice are interpreted to indicate that the LCR interacts not only with the minimal gamma gene promoter but also with sequences of the upstream promoter. We postulate that gamma gene downregulation is achieved when the interaction between LCR and the upstream promoter is disturbed by the silencer located in the -382 to -730 region. We propose that gamma gene silencing is achieved by the combined effect of negative elements located 3' to -141, the negative element located between -382 and -730, and the competition by the beta gene promoter during the adult stage of development.
PMCID: PMC364835  PMID: 8246980
23.  Utilization Effect of Integrating a Chest Radiography Room into a Thoracic Surgery Ward 
Bedside chest radiography (bCXR) represents a substantial fraction of the volume of medical imaging for inpatient healthcare facilities. However, its image quality is limited compared to posterior-anterior/lateral (PA/LAT) acquisitions taken radiographic rooms. We evaluated utilization of bCXR and other chest imaging modalities before and after placing a radiography room within our thoracic surgical inpatient ward.
Institutional review board approval was obtained for this HIPAA-compliant. We retrospectively identified all patient admissions (3,852) to the thoracic surgical units between April 1, 2007 and December 31, 2010. All chest imaging tests performed for these patients including computed tomography (CT) scans, magnetic resonance imaging (MRI), ultrasound (US), bedside and PA/LAT radiographs were counted. Our primary outcome measure was chest imaging utilization, defined as the number of chest examinations per admission, pre- and post-establishment of the digital radiography room on January, 10th 2010. Statistical analysis was performed using an independent-samples t-test to evaluate changes in chest imaging utilization.
We observed a 2.61 fold increase in the number of PA/LAT CXR per admission (p<0.01) and a 1.96 fold decrease in the number of bCXR per admission (p<0.01) post radiography room implementation. The number of chest CT, MRI and US per admission did not change significantly.
Establishing a radiography room physically within thoracic surgery units or in close proximity can significantly shift CXR utilization from bedside to PA/LAT acquisitions, which may enable opportunities for improvement in efficiency, quality, and safety in patient care.
PMCID: PMC3361677  PMID: 22632669
Chest imaging; workflow improvement; imaging utilization; radiography room; radiology resource optimization
24.  Proximal caries detection accuracy using intraoral bitewing radiography, extraoral bitewing radiography and panoramic radiography 
Dentomaxillofacial Radiology  2012;41(6):450-459.
To compare proximal caries detection using intraoral bitewing, extraoral bitewing and panoramic radiography.
80 extracted human premolar and molar teeth with and without proximal caries were used. Intraoral radiographs were taken with Kodak Insight film (Eastman Kodak Co., Rochester, NY) using the bitewing technique. Extraoral bitewing and panoramic images were obtained using a Planmeca Promax Digital Panoramic X-ray unit (Planmeca Inc., Helsinki, Finland). Images were evaluated by three observers twice. In total, 160 proximal surfaces were assessed. Intra- and interobserver kappa coefficients were calculated. Scores obtained from the three techniques were compared with the histological gold standard using receiver operating characteristic analysis. Az values for each image type, observer and reading were compared using z-tests, with a significance level of α = 0.05.
Kappa coefficients ranged from 0.883 to 0.963 for the intraoral bitewing, from 0.715 to 0.893 for the extraoral bitewing, and from 0.659 to 0.884 for the panoramic radiography. Interobserver agreements for the first and second readings for the intraoral bitewing images were between 0.717 and 0.780, the extraoral bitewing readings were between 0.569 and 0.707, and the panoramic images were between 0.477 and 0.740. The Az values for both readings of all three observers were highest for the intraoral bitewing. Az values for the extraoral bitewing images were higher than those of the panoramic images without statistical significance (p > 0.05).
Intraoral bitewing radiography was superior to extraoral bitewing and panoramic radiography in diagnosing proximal caries of premolar and molar teeth ex vivo. Similar intra- and interobserver coefficients were calculated for extraoral bitewing and panoramic radiography.
PMCID: PMC3520392  PMID: 22868296
dental caries; radiography; panoramic radiography; bitewing radiography
25.  Evaluation of a Noise Reduction Procedure for Chest Radiography 
Yonago Acta Medica  2013;56(4):85-91.
The aim of this study was to evaluate the usefulness of noise reduction procedure (NRP), a function in the new image processing for chest radiography.
A CXDI-50G Portable Digital Radiography System (Canon) was used for X-ray detection. Image noise was analyzed with a noise power spectrum (NPS) and a burger phantom was used for evaluation of density resolution. The usefulness of NRP was evaluated by chest phantom images and clinical chest radiography. We employed the Bureau of Radiological Health Method for scoring chest images while carrying out our observations.
NPS through the use of NRP was improved compared with conventional image processing (CIP). The results in image quality showed high-density resolution through the use of NRP, so that chest radiography examination can be performed with a low dose of radiation. Scores were significantly higher than for CIP.
In this study, use of NRP led to a high evaluation in these so we are able to confirm the usefulness of NRP for clinical chest radiography.
PMCID: PMC3935175  PMID: 24574577
chest radiography; image processing; noise power spectrum; noise reduction procedure; observation

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