Gridless adult cervical spine radiography and its' effect on image quality and radiation dose: A phantom study.

INTRODUCTION: Imaging of the cervical spine in general radiography is most frequently performed using an anti-scatter grid. The purpose of this study was to investigate the effects of a gridless setting on image quality and radiation dose during digital radiography of the anteroposterior (AP) and lateral (LAT) cervical spine. METHODS: A phantom study was performed with a variety of tube voltages (63-75 kV) with and without an anti-scatter grid. The tube current time product (mAs) and dose area product (DAP) were recorded and used to calculate effective dose (ED) and individual organ dose using PCXMC 2.0 software, as well as entrance surface dose (ESD) and objective image quality: signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Subjective visual image quality grading characteristics (VGC) was performed by five qualified radiographers. RESULTS: In a gridless setting, the AP and LAT positions showed significantly lower DAP (1.6 µGym2; 61.3 % and 1.6 µGym2; 51.2%), ESD (27.6 µGy; 57.3% and 77.2 µGy; 47.2%) and ED (4.2 µSv; 61.3% and 2.3 µSv; 48.9%). In a gridless setting in the AP position, there is a slight significant deterioration in image quality. In the lateral projection, on the other hand, the image quality without the use of grid was only significantly reduced in three of six criteria and there was no difference in the objective image quality between the two settings examined. CONCLUSION: The results of this study show that gridless setting significantly decreases radiation dose and image quality, but the quality in the lateral projection is still acceptable for diagnostic purpose. IMPLICATIONS FOR PRACTICE: The protocol without the use of the anti-scatter grid in cervical spine radiography leads to a reduction in the radiation dose in both projections, but the image quality in the AP is significantly reduced for all criteria examined, with a slight deterioration in image quality in the lateral projection.

Impact of gonad shielding for AP pelvis on dose and image quality on different female sizes: A phantom study.

INTRODUCTION: In clinical practice AP pelvis standard protocols are suitable for average size patients. However, as the average body size has increased over the past decades, radiographers have had to improve their practice in order to ensure that adequate image quality with minimal radiation dose to the patient is achieved. Gonad shielding has been found to be an effective way to reduce the radiation dose to the ovaries. However, the effect of increased body size, or fat thickness, in combination with gonad shielding is unclear. The goal of the study was to investigate the impact of gonad shielding in a phantom of adult female stature with increasing fat thicknesses on SNR (as a measure for image quality) and dose for AP pelvis examination. METHODS: An adult Alderson female pelvis phantom was imaged with a variety of fat thickness categories as a representation of increasing BMI. 72 images were acquired using both AEC and manual exposure with and without gonad shielding. The radiation dose to the ovaries was measured using a MOSFET system. The relationship between fat thickness, SNR and dose when the AP pelvis was performed with and without shielding was investigated using the Wilcoxon signed rank test. P-values < 0.05 were considered to be statistically significant. RESULTS: Ovary dose and SNR remained constant despite the use of gonad shielding while introducing fat layers. CONCLUSION: The ovary dose did not increase with an increase of fat thickness and the image quality was not altered. IMPLICATIONS FOR PRACTICE: Based on this phantom study it can be suggested that obese patients can expect the same image quality as average patients while respecting ALARA principle when using adequate protocols.

Comparison of Outcomes Following a Switch From a Brand to an Authorized Versus Independent Generic Drug.

Authorized generics are identical in formulation to brand drugs, manufactured by the brand company but marketed as a generic. Generics, marketed by generic manufacturers, are required to demonstrate pharmaceutical and bioequivalence to the brand drug, but repetition of clinical trials is not required. This retrospective cohort study compared outcomes for generics and authorized generics, which serves as a generic vs. brand proxy that minimizes bias against generics. For the seven drugs studied between 1999 and 2014, 5,234 unique patients were on brand drugs prior to generic entry and 4,900 (93.6%) switched to a generic. During the 12 months following the brand-to-generic switch, patients using generics vs. authorized generics were similar in terms of outpatient visits, urgent care visits, hospitalizations, and medication discontinuation. The likelihood of emergency department (ED) visits was slightly higher for authorized generics compared with generics. These data suggest that generics were clinically no worse than their proxy brand comparators.

A genome-wide association study identifies variants in KCNIP4 associated with ACE inhibitor-induced cough.

The most common side effect of angiotensin-converting enzyme inhibitor (ACEi) drugs is cough. We conducted a genome-wide association study (GWAS) of ACEi-induced cough among 7080 subjects of diverse ancestries in the Electronic Medical Records and Genomics (eMERGE) network. Cases were subjects diagnosed with ACEi-induced cough. Controls were subjects with at least 6 months of ACEi use and no cough. A GWAS (1595 cases and 5485 controls) identified associations on chromosome 4 in an intron of KCNIP4. The strongest association was at rs145489027 (minor allele frequency=0.33, odds ratio (OR)=1.3 (95% confidence interval (CI): 1.2-1.4), P=1.0 × 10(-8)). Replication for six single-nucleotide polymorphisms (SNPs) in KCNIP4 was tested in a second eMERGE population (n=926) and in the Genetics of Diabetes Audit and Research in Tayside, Scotland (GoDARTS) cohort (n=4309). Replication was observed at rs7675300 (OR=1.32 (1.01-1.70), P=0.04) in eMERGE and at rs16870989 and rs1495509 (OR=1.15 (1.01-1.30), P=0.03 for both) in GoDARTS. The combined association at rs1495509 was significant (OR=1.23 (1.15-1.32), P=1.9 × 10(-9)). These results indicate that SNPs in KCNIP4 may modulate ACEi-induced cough risk.

A polymorphism in HLA-G modifies statin benefit in asthma.

Several reports have shown that statin treatment benefits patients with asthma; however, inconsistent effects have been observed. The mir-152 family (148a, 148b and 152) has been implicated in asthma. These microRNAs suppress HLA-G expression, and rs1063320, a common SNP in the HLA-G 3'UTR that is associated with asthma risk, modulates miRNA binding. We report that statins upregulate mir-148b and 152, and affect HLA-G expression in an rs1063320-dependent fashion. In addition, we found that individuals who carried the G minor allele of rs1063320 had reduced asthma-related exacerbations (emergency department visits, hospitalizations or oral steroid use) compared with non-carriers (P=0.03) in statin users ascertained in the Personalized Medicine Research Project at the Marshfield Clinic (n=421). These findings support the hypothesis that rs1063320 modifies the effect of statin benefit in asthma, and thus may contribute to variation in statin efficacy for the management of this disease.

The utility of BMD Z-score diagnostic thresholds for secondary causes of osteoporosis.

UNLABELLED: This very large dual X-ray absorptiometry (DXA) cohort confirmed a significant, inverse relationship between bone mineral density (BMD) Z-scores and the presence of secondary causes of osteoporosis but receiver operating characteristic (ROC) curves indicate that Z-score diagnostic thresholds (such as -2.0) discriminate poorly between the presence and absence of secondary causes of osteoporosis. INTRODUCTION: BMD Z-score diagnostic thresholds have been proposed to detect secondary causes of osteoporosis. To determine the sensitivity and diagnostic utility of such thresholds, we analyzed comprehensive BMD and personal health information data from a large, multispecialty group practice. METHODS: Adult subjects were assigned their lowest axial BMD Z-score and ICD-9 diagnosis codes for secondary causes of osteoporosis when cited at least twice in their electronic medical record. Multiple logistic regression was used to model the prevalence of matching ICD-9 codes as a function of Z-score. ROC curves were used to investigate various Z-score cut points for sensitivity and specificity. RESULTS: Eighteen thousand six hundred seventy-four subjects were analyzed. Secondary causes of osteoporosis were identified in 31% of men and 16% of women. The frequency of secondary causes varied with age and between genders and varied inversely with Z-score. No inflection point was observed in this relationship to suggest a useful clinical decision threshold. The difference in mean Z-score of those with and without a secondary cause of osteoporosis was biologically slight (±0.3). Low Z-score diagnostic thresholds were insensitive to the presence of secondary causes of osteoporosis and provided relatively poor predictive value. CONCLUSIONS: This DXA cohort confirmed a significant inverse relationship between Z-score and the presence of secondary causes of osteoporosis but diagnostic Z-score thresholds discriminate poorly between the presence and absence of secondary causes of osteoporosis. If only patients with very low Z-scores are evaluated for secondary causes of osteoporosis the diagnostic specificity may be high but most cases will be missed.

Evaluation of a policy to reduce youth tractor crashes on public roads.

OBJECTIVE: Evaluate the effectiveness of a United States state law, Wisconsin Act 455, in reducing highway tractor crashes involving youth operators. DESIGN: Policy outcome evaluation involving review of a retrospective case series. SETTING: Youth highway tractor crashes from Wisconsin for the years 1994-2003 that resulted in a fatality, injury, and/or property damage. SUBJECTS: One hundred and forty six tractor crash cases involving operators younger than 16 years. METHODS: Describe and model the tractor crash patterns before and after enactment of the law, and examine the relation between the contributing circumstances identified in the crash reports and the content covered in the mandated tractor certification course. RESULTS: There was neither a significant change in the number of youth tractor crashes after the law was passed, nor any reduction in the proportion of crashes where the youth operator was designated at fault. The tractor certification course did not cover the major factors contributing to youth tractor crashes on public roads. CONCLUSIONS: No significant effect of the law was detected and crash rates at the end of the study period were similar to those before Wisconsin Act 455. The authors'findings should not be construed to suggest that public policy, in general, is an ineffective strategy for the prevention of pediatric agricultural injuries. Negotiating a balance in public policy debates will be a challenge, but it is clear that future policy initiatives need to identify and implement the right policy for the right problem.

Pediatric farm injuries involving non-working children injured by a farm work hazard: five priorities for primary prevention.

OBJECTIVES: To describe pediatric farm injuries experienced by children who were not engaged in farm work, but were injured by a farm work hazard and to identify priorities for primary prevention. DESIGN: Secondary analysis of data from a novel evaluation of an injury control resource using a retrospective case series. DATA SOURCES: Fatal, hospitalized, and restricted activity farm injuries from Canada and the United States. SUBJECTS: Three hundred and seventy known non-work childhood injuries from a larger case series of 934 injury events covering the full spectrum of pediatric farm injuries. METHODS: Recurrent injury patterns were described by child demographics, external cause of injury, and associated child activities. Factors contributing to pediatric farm injury were described. New priorities for primary prevention were identified. RESULTS: The children involved were mainly resident members of farm families and 233/370 (63.0%) of the children were under the age of 7 years. Leading mechanisms of injury varied by data source but included: bystander and passenger runovers (fatalities); drowning (fatalities); machinery entanglements (hospitalizations); falls from heights (hospitalizations); and animal trauma (hospitalizations, restricted activity injuries). Common activities leading to injury included playing in the worksite (all data sources); being a bystander to or extra rider on farm machinery (all data sources); recreational horseback riding (restricted activity injuries). Five priorities for prevention programs are proposed. CONCLUSIONS: Substantial proportions of pediatric farm injuries are experienced by children who are not engaged in farm work. These injuries occur because farm children are often exposed to an occupational worksite with known hazards. Study findings could lead to more refined and focused pediatric farm injury prevention initiatives.

Evaluation of the North American Guidelines for Children's Agricultural Tasks using a case series of injuries.

OBJECTIVE: To evaluate the potential for the North American Guidelines for Children's Agricultural Tasks (NAGCAT) to prevent the occurrence of pediatric farm injuries. This evaluation focuses upon farm injuries experienced when children were engaged in farm work. DESIGN: Novel outcome evaluation involving primary review of three retrospective case series. SETTING: Fatal, hospitalized, and restricted activity injuries from the United States and Canada. SUBJECTS: Nine hundred and thirty four pediatric farm injury cases. METHODS: The applicability of NAGCAT to each case was rated. For injuries where NAGCAT were applicable, recurrent injury patterns were described and the potential for NAGCAT to prevent their occurrence was assessed. RESULTS: A total of 283 (30.3%) cases involved children engaged in farm work. There was an applicable NAGCAT guideline in 64.9% of the work related cases. Leading individual guidelines applicable to the injury events were: (1) working with large animals; (2) driving a farm tractor; and (3) farm work with an all-terrain vehicle. In the judgment of the research team, 59.6% of these injuries were totally preventable if the principles espoused by NAGCAT had been applied. CONCLUSIONS: NAGCAT are a set of consensus guidelines aimed at the prevention of pediatric farm injuries. The findings suggest that NAGCAT, if applied, would be efficacious in preventing many of the most serious injuries experienced by children engaged in farm work. However, work related injuries represent only a modest portion of pediatric farm injuries. This new information assists in the refinement of NAGCAT as an injury control resource and puts its potential efficacy into context.