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The ACR Dose Index Registry (DIR) provides a new source of clinical radiation exposure data that has not been used previously to establish or update the relative radiation level (RRL) values in the ACR Appropriateness Criteria (AC). The results of a recent review of DIR data for 10 common CT examinations were compared with current ACR AC RRL values for the same procedures. The AC RRL values were previously determined by consensus of members of the AC Radiation Exposure Subcommittee based on reference radiation dose values from the literature (when available) and anecdotal information from individual members’ clinical practices and experiences. For 7 of the 10 examination types reviewed, DIR data agreed with existing RRL values. For 3 of 10 examination types, DIR data reflected lower dose values than currently rated in the AC. The Radiation Exposure Subcommittee will revise these RRL assignments in a forthcoming update to the AC (in October 2018) and will continue to monitor the DIR and associated reviews and analyses to refine RRL assignments for additional examination types. Given recent attention and efforts to reduce radiation exposure in CT and other imaging modalities, it is likely that other examination types will require revision of RRL assignments once information from the DIR database is considered.  相似文献   
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Objective To explore how the size of the growth plate changes with age using three-dimensional (3D) models of the distal femoral and proximal tibial growth plates in pediatric patients.Design and patients We retrospectively created 3D models of the normal unaffected distal femoral (n=20) and proximal tibial (n=10) growth plates in 14 patients (9 males, 5 females) age range 3.8–15.6 years who were referred for evaluation of premature partial closure of the growth plate or hyaline cartilage abnormality. All patients had one or more 3D fat-suppressed spoiled GRASS sequence from which models were made of normal growth plates. Total projected area was estimated from standardized maximum intensity projection (MIP) views, and volume was computed from the entire model. We also included the total projected area of the distal femur (n=7) or proximal tibia (n=8) in 11 patients (8 males, 3 females, 5–13 years) who had previously been evaluated for bone bridging.Results The 3D femoral and tibial growth plate anatomy was displayed. Femoral growth plate area varied from 804 mm2 to 3,463 mm2. Femoral physeal cartilage volume varied from 2.1 cm3 to 12.6 cm3. Tibial growth plate area varied from 736 mm2 to 3,026 mm2. Tibial physeal cartilage volume varied from 1.9 cm3 to 13.2 cm3. The growth plate area values appear to increase linearly with increasing age.Conclusions The distal femoral and proximal tibial physeal plates have complex anatomy. Both area and volume of the growth plates appeared to follow a linear increase with age and reached a plateau in adolescence, although there was some scatter. Area appears to have less measurement variability than volume, and may be a more reliable predictor of growth plate tissue quantity.  相似文献   
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A large increase in the use of kidneys from donation after circulatory death (DCD) donors prompted us to examine the impact of donor type on the incidence of ureteric complications (UCs; ureteric stenosis, urinary leak) after kidney transplantation. We studied 1072 consecutive kidney transplants (DCD n=494, live donor [LD] n=273, donation after brain death [DBD] n=305) performed during 2008‐2014. Overall, there was a low incidence of UCs after kidney transplantation (3.5%). Despite a trend toward higher incidence of UCs in DCD (n=22, 4.5%) compared to LD (n=10, 3.7%) and DBD (n=5, 1.6%) kidney transplants, donor type was not a significant risk factor for UCs in multivariate analysis (DCD vs DBD HR: 2.33, 95% CI: 0.77‐7.03, P=.13). There was no association between the incidence of UCs and donor, recipient, or transplant‐related characteristics. Management involved surgical reconstruction in the majority of cases, with restenosis in 2.7% requiring re‐operation. No grafts were lost secondary to UCs. Despite a significant increase in the number of kidney transplants from DCD donors, the incidence of UCs remains low. When ureteric complications do occur, they can be treated successfully with surgical reconstruction with no adverse effect on graft or patient survival.  相似文献   
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Background

Klippel-Trénaunay syndrome (KTS) is a severe vascular malformation that can lead to hypertrophic osteoarthritis. Total knee arthroplasty (TKA) performed in extremities affected with KTS is challenging given the high-risk vascular considerations and occasionally poor bone quality.

Methods

We identified 12 patients with KTS who underwent TKA between 1998 and 2017. There were 7 men, mean age 42 years, and mean follow-up was 7 years. Before arthroplasty, 2 patients (17%) had preoperative sclerotherapy. Preoperative vascular studies were done for 9 patients (75%) and included magnetic resonance imaging (n = 7), magnetic resonance angiography (n = 1), and computed tomography angiography (n = 1). A preoperative blood conservation protocol was used for all operations and included the use of tranexamic acid (TXA) in later years. Posterior-stabilized TKA was used in 10 cases and cruciate-retaining TKA was used in 2 cases.

Results

At final follow-up, 2 patients (17%) had undergone revision surgery: 1 for infection and 1 for tibial loosening with subsequent arthrofibrosis. Knee Society Scores (36-83, P < .0001) and functional scores (48-84, P = .0007) significantly increased between the preoperative and postoperative period. Likewise at last follow-up, the mean knee range of motion significantly increased (82°-104°, P = .04). Median blood loss for patients who received TXA was 200 mL compared to 275 mL in patients who did not receive TXA (P = .66). Likewise there was no difference (P = .5) in the proportion of patients who required a transfusion between those who received TXA (2/6, 33%) and those who did not (3/6, 50%).

Conclusion

In this small series, TKA can lead to significant clinical improvement for patients with KTS. Modern blood management techniques and a careful multidisciplinary care approach render TKA a reasonable option for select patients with KTS.

Level of Evidence

Level IV case series, therapeutic.  相似文献   
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Arsenic is measurable in tobacco and cigarette mainstream smoke (MSS). Whether arsenic has an independent role in diseases associated with tobacco consumption is not known. Epidemiology and biomonitoring data and probabilistic risk assessment (PRA) methods were used to investigate this potential association. Analysis of data from the National Health and Nutrition Examination Survey (NHANES) showed that urine arsenic concentrations in tobacco consumers were not different or were lower than levels in non-consumers of tobacco. Additionally, urine arsenic levels from NHANES tobacco consumers were five-times or more lower than levels reported in epidemiology studies to be associated with adverse health effects. Results of PRA indicated that mean non-cancer hazard estimates and mean incremental lifetime cancer risk estimates were within accepted ranges. Taken together, these results suggest that arsenic may not be independently associated with tobacco consumption or diseases related to tobacco consumption.  相似文献   
39.
BACKGROUND: Saudi Arabia is hyperendemic for brucellosis, with more than 8000 cases reported each year to public health authorities. During 1998, brucellosis ranked as the No. 1 reportable communicable disease (22.5%) in Saudi Arabian National Guard communities. King Fahad Hospital is the major referral center for National Guard personnel in the nation's central region.Methods And Results: From 1991 to 2000, brucellosis developed in 7 expatriate hospital employees. Six employees were bacteriology technologists, and one was a pathologist. Each had a clinical syndrome compatible with brucellosis (headache, fever, rigors, sweats, and myalgias) plus elevated Brucella sp serum agglutinin titers > or = 1:1280; one patient also had positive blood cultures. All patients responded to anti-Brucella therapy. Two patients had relapses, and complications occurred in four patients (septic endophlebitis of the leg, infected prosthesis, epididymoorchitis, and lumbar spondylitis). In all these employees except the pathologist, the infection was associated with processing Brucella sp cultures. CONCLUSION: Despite the enforcement of stringent infection control measures including the use of a class II biosafety hood in the laboratory, the problem of nosocomial brucellosis persists because of the large number of infected specimens handled by the laboratory (17,500 specimens per year). Ultimately, risk reduction depends on efforts to reduce disease endemicity in the country. In the meantime, conversion of the laboratory to biosafety level 3 is under way.  相似文献   
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