Radiation Dose Survey for Common Computed Tomography Exams: 2013 British Columbia Results

2016 ◽  
Vol 67 (1) ◽  
pp. 88-95 ◽  
Author(s):  
Yogesh Thakur ◽  
Thorarin A. Bjarnason ◽  
Patricia Baxter ◽  
Mitch Griffith ◽  
Kirk Eaton
Keyword(s):  
Computed Tomography ◽  
British Columbia ◽  
New Technologies ◽  
New Technology ◽  
International Standards ◽  
Filtered Backprojection ◽  
Significant Difference ◽  
Patient Doses ◽  
Ct Data ◽  
Health Canada

In 2013 Health Canada conducted a national survey of computed tomography (CT) radiation usage. We analysed contributions from all 7 public health authorities in the province of British Columbia, which covered scanner age, number of slices, and common adult protocols (≥19 years: 70 ± 20 kg, head, chest, abdomen/pelvis, and trunk). Patient doses were recorded for common protocols. Diagnostic reference levels (DRLs) was calculated using scanner data with >10 patient doses recorded for each protocol. Data was analysed based on image reconstruction (filtered backprojection vs iterative reconstruction [IR] vs IR available but not in use). Provincial response was 92%, with 59 of 64 CT data used for analysis. The average scanner age was 5.5 years old, with 39% of scanners installed between 2008-2013; 78.5% of scanners were multislice (>64 slices), and 44% of scanners had IR available. Overall British Columbia DRLs were: head = 1305, chest = 529, abdomen/pelvis = 819, and trunk = 1225. DRLs were consistent with Health Canada recommendations and other Canadian published values, but above international standards. For sites with IR available, less than 50% used this technology routinely for head, chest and trunk exams. Overall, use of IR reduced radiation usage between 11%-32% compared to filtered backprojection, while sites using IR vs IR available used 30%/43% less radiation for head/chest exams ( P < .05). No significant difference was observed for abdomen/pelvis exams ( P = .385). With the fast pace of CT technical advancement, DRLs should reflect the technology used, instead of just globally applied to anatomical regions. Federal guidelines should be updated at a higher frequency to reflect new technology. In addition, new technologies must be utilised to optimize image quality vs radiation usage.

scholarly journals A Dynamic Theory of Expertise and Occupational Boundaries in New Technology Implementation: Building on Barley's Study of CT Scanning

2004 ◽  
Vol 49 (4) ◽  
pp. 572-607
Author(s):  
Laura J. Black ◽  
Paul R. Carlile ◽  
Nelson P. Repenning
Keyword(s):  
Computed Tomography ◽  
Dynamic Model ◽  
Social Action ◽  
Technology Implementation ◽  
New Technologies ◽  
Dynamic Theory ◽  
New Technology ◽  
Ct Scanning ◽  
Ethnographic Data ◽  
Expected Benefits

In this paper, we develop a theory to explain why the implementation of new technologies often disrupts occupational roles in ways that delay the expected benefits. To explore these disruptions, we construct a dynamic model grounded in ethnographic data from Barley's widely cited (1986) study of computed tomography (CT) as implemented in two hospitals. Using modeling, we formalize the recursive relationship between the activity of CT scanning and the types and accumulations of knowledge used by doctors and technologists. We find that a balance of expertise across occupational boundaries in operating the technology creates a pattern in which the benefits of the new technology are likely to be realized most rapidly. By operationalizing the dynamics between knowledge and social action, we specify more clearly the recursive relationship between structuring and structure. *

The Recent Revolution in High Performance Computing

MRS Bulletin ◽  
1997 ◽  
Vol 22 (10) ◽  
pp. 5-6
Author(s):  
Horst D. Simon
Keyword(s):  
High Performance Computing ◽  
High Performance ◽  
New Technologies ◽  
New Technology ◽  
Parallel Architecture ◽  
Time Frame ◽  
Good News ◽  
Computing Industry ◽  
Time And Energy ◽  
Performance Computing

Recent events in the high-performance computing industry have concerned scientists and the general public regarding a crisis or a lack of leadership in the field. That concern is understandable considering the industry's history from 1993 to 1996. Cray Research, the historic leader in supercomputing technology, was unable to survive financially as an independent company and was acquired by Silicon Graphics. Two ambitious new companies that introduced new technologies in the late 1980s and early 1990s—Thinking Machines and Kendall Square Research—were commercial failures and went out of business. And Intel, which introduced its Paragon supercomputer in 1994, discontinued production only two years later.During the same time frame, scientists who had finished the laborious task of writing scientific codes to run on vector parallel supercomputers learned that those codes would have to be rewritten if they were to run on the next-generation, highly parallel architecture. Scientists who are not yet involved in high-performance computing are understandably hesitant about committing their time and energy to such an apparently unstable enterprise.However, beneath the commercial chaos of the last several years, a technological revolution has been occurring. The good news is that the revolution is over, leading to five to ten years of predictable stability, steady improvements in system performance, and increased productivity for scientific applications. It is time for scientists who were sitting on the fence to jump in and reap the benefits of the new technology.

Calcium-Suppressed Technique in Dual-Layer Detector Computed Tomography to Evaluate Knee Articular Cartilage

2020 ◽  
Vol 16 ◽  
Author(s):  
Qinglin Meng ◽  
Mengqi Liu ◽  
Weiwei Deng ◽  
Ke Chen ◽  
Botao Wang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Bone Marrow ◽  
Articular Cartilage ◽  
Bone Marrow Edema ◽  
Knee Joints ◽  
Infrapatellar Fat Pad ◽  
Proton Density ◽  
Knee Cartilage ◽  
Significant Difference ◽  
Marrow Edema

Background: Calcium-suppressed (CaSupp) technique involving spectral-based images has been used to observe bone marrow edema by removing calcium components from the image. Objective: This study aimed to evaluate the knee articular cartilage using the CaSupp technique in dual-layer detector computed tomography (DLCT). Methods: Twenty-eight healthy participants and two patients with osteoarthritis were enrolled, who underwent DLCT and magnetic resonance imaging (MRI) examination. CaSupp images were reconstructed from spectral-based images using a calcium suppression algorithm and were overlaid conventional CT images for visual evaluation. The morphology of the knee cartilage was evaluated, and the thickness of the articular cartilage was measured on sagittal proton density– weighted and CaSupp images in the patellofemoral compartment. Results: No abnormal signal or density, cartilage defect, and subjacent bone ulceration were observed in the lateral and medial femorotibial compartments and the patellofemoral compartment on MRI images and CaSupp images for the 48 normal knee joints. CaSupp images could clearly identify cartilage thinning, defect, subjacent bone marrow edema, and edema of the infrapatellar fat pad in the same way as MRI images in the three knee joints with osteoarthritis. A significant difference was found in the mean thickness of the patellar cartilage between MRI images and CaSupp images, while the femoral cartilage presented no significant difference in thickness between MRI images and CaSupp images over all 48 knee joints. Conclusion: The present study demonstrated that CaSupp images could effectively be used to perform the visual and quantitative assessment of knee cartilage.

The diagnosis of early pneumoconiosis in dust-exposed workers: comparison of chest radiography and computed tomography

2021 ◽  
pp. 028418512110225
Author(s):  
Hideyuki Hayashi ◽  
Kazuto Ashizawa ◽  
Masashi Takahashi ◽  
Katsuya Kato ◽  
Hiroaki Arakawa ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Chest Radiography ◽  
Pulmonary Emphysema ◽  
Early Stage ◽  
Pathological Changes ◽  
Occupational History ◽  
Exposed Workers ◽  
History Of ◽  
Ct Data ◽  
Positive Results

Background Chest radiography (CR) is employed as the evaluation of pneumoconiosis; however, we sometimes encounter cases in which computed tomography (CT) is more effective in detecting subtle pathological changes or cases in which CR yields false-positive results. Purpose To compare CR to CT in the diagnosis of early-stage pneumoconiosis. Material and Methods CR and CT were performed for 132 workers with an occupational history of mining. We excluded 23 cases of arc-welder’s lung. Five readers who were experienced chest radiologists or pulmonologists independently graded the pulmonary small opacities on CR of the remaining 109 cases. We then excluded 37 cases in which the CT data were not sufficient for grading. CT images of the remaining 72 cases were graded by the five readers. We also assessed the degree of pulmonary emphysema in those cases. Results The grade of profusion on CR (CR score) of all five readers was identical in only 5 of 109 cases (4.6%). The CR score coincided with that on CT in 40 of 72 cases (56%). The CT score was higher than that on CR in 13 cases (18%). On the other hand, the CT score was lower than that on CR in 19 cases (26%). The incidence of pulmonary emphysema was significantly higher in patients whose CR score was higher than their CT score. Conclusion CT is more sensitive than CR in the evaluation of early-stage pneumoconiosis. In cases with emphysema, the CR score tends to be higher in comparison to that on CT.

scholarly journals A comparison between Asians and Caucasians in the dimensions of the femoral isthmus based on a 3D-CT analysis of 1189 adult femurs

2021 ◽  
Author(s):  
Darius M. Thiesen ◽  
Dimitris Ntalos ◽  
Alexander Korthaus ◽  
Andreas Petersik ◽  
Karl-Heinz Frosch ◽  
...  
Keyword(s):  
Proximal Femur ◽  
Strong Predictor ◽  
Matched Pair ◽  
3D Ct ◽  
Femur Fractures ◽  
Matched Pair Analysis ◽  
Significant Difference ◽  
Ct Analysis ◽  
Ct Data ◽  
The Individual

Abstract Introduction For successful intramedullary implant placement at the femur, such as nailing in unstable proximal femur fractures, the use of an implant that at least reaches or exceeds the femoral isthmus and yields sufficient thickness is recommended. A number of complications after intramedullary femoral nailing have been reported, particularly in Asians. To understand the anatomical features of the proximal femur and their ethnic differences, we aimed to accurately calculate the femoral isthmus dimensions and proximal distance of Asians and Caucasians. Methods In total, 1189 Asian and Caucasian segmented 3D CT data sets of femurs were analyzed. The individual femoral isthmus diameter was precisely computed to investigate whether gender, femur length, age, ethnicity or body mass index have an influence on isthmus diameters. Results The mean isthmus diameter of all femurs was 10.71 ± 2.2 mm. A significantly larger diameter was found in Asians when compared to Caucasians (p < 0.001). Age was a strong predictor of the isthmus diameter variability in females (p < 0.001, adjusted r2 = 0.299). With every year of life, the isthmus showed a widening of 0.08 mm in women. A Matched Pair Analysis of 150 female femurs showed a significant difference between isthmus diameter in Asian and Caucasian femurs (p = 0.05). In 50% of the cases the isthmus was found in a range of 2.4 cm between 16.9 and 19.3 cm distal to the tip of the greater trochanter. The female Asian femur differs from Caucasians as it is wider at the isthmus. Conclusions In absolute values, the proximal isthmus distance did not show much variation but is more proximal in Asians. The detailed data presented may be helpful in the development of future implant designs. The length and thickness of future standard implants may be considered based on the findings.

scholarly journals Correlation between uniocular deviation and duction changes following different decompression surgeries in thyroid eye disease

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jie Guo ◽  
Xiaofeng Li ◽  
Ruiqi Ma ◽  
Jiang Qian
Keyword(s):  
Computed Tomography ◽  
Lateral Wall ◽  
Contractile Force ◽  
Thyroid Eye Disease ◽  
Eye Disease ◽  
Decompression Surgery ◽  
Inferior Wall ◽  
Orbital Decompression ◽  
Significant Difference ◽  
Ocular Deviation

Abstract Background Postoperative ocular imbalance is an important problem for orbital decompression surgery in thyroid eye disease (TED). The aim of this study was to evaluate the changes in unilateral ocular deviation and duction following orbital decompression and discuss the biomechanics of ocular imbalance. Methods Fifty-four TED patients who underwent unilateral orbital decompression were included. Fifteen patients underwent 1-wall (deep lateral wall) decompression, 18 patients underwent 2-wall (deep lateral and medial wall) decompression and 21 patients underwent 3-wall (deep lateral, medial and inferior wall) decompression. Objective and subjective deviation of the operated eyes were evaluated using the prism test and synoptophore, respectively. Ocular ductions were measured using Hirschberg’s method. The diameters of the extraocular rectus were measured by computed tomography. Results Ocular deviation and duction showed no significant difference after 1-wall decompression (p = 0.25–0.89). Esotropia increased after 2-wall decompression (p = 0.001–0.02), and hypotropia increased after 3-wall decompression (p = 0.02). Adduction increased but abduction decreased following 2-wall and 3-wall decompression (p < 0.05). Infraduction increased following 3-wall decompression (p < 0.001). Additionally, the increase in esotropia was significantly correlated with the increase in adduction and with the decrease in abduction (r = 0.37–0.63, p < 0.05). There were significant correlations between the diameter of the medial rectus and the increase in esotropia, the increase in adduction and the decrease in abduction postoperatively (r = 0.35–0.48, p < 0.05). Conclusions The changes in ocular deviation and duction were different after 1-wall, 2-wall and 3-wall orbital decompression. The increased contractile force of the rectus may be an important reason for strabismus changes after orbital decompression surgery.

scholarly journals Temporomandibular Joint Osseous Morphology of Class I and Class II Malocclusions in the Normal Skeletal Pattern: A Cone-Beam Computed Tomography Study

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 541
Author(s):  
Xiao-Chuan Fan ◽  
Lin-Sha Ma ◽  
Li Chen ◽  
Diwakar Singh ◽  
Xiaohui Rausch-Fan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Temporomandibular Joint ◽  
Cone Beam Computed Tomography ◽  
Class Ii ◽  
Class I ◽  
Cone Beam ◽  
Glenoid Fossa ◽  
Linear Measurements ◽  
Significant Difference ◽  
Skeletal Pattern

(1) Background—The aim of the present study was to evaluate the correlation between the temporomandibular joint (TMJ) osseous morphology of normal skeletal pattern individuals with different dental malocclusions by using cone-beam computed tomography (CBCT). (2) Methods—The CBCT images of bilateral TMJs in 67 subjects with skeletal class I and average mandibular angle (26 males and 41 females, age range 20–49 years) were evaluated in this study. The subjects were divided into class I, class II division 1, and class II division 2 according to the molar relationship and retroclination of the maxillary incisors. Angular and linear measurements of TMJ were evaluated and the differences between the groups were statistically analyzed. (3) Results—Intragroup comparisons showed statistical differences for articular eminence inclination, the width of the glenoid fossa, the ratio of the width of the glenoid fossa to the depth of the glenoid fossa, the condylar angle, and the intercondylar angle between the malocclusion groups. The measurements of the glenoid fossa shape showed no significant difference between the left and right sides. Females showed more differences in the morphological parameters of TMJ between the three malocclusion groups than the males. (4) Conclusion—The present study revealed differences in the TMJ osseous morphology between dental class I and class II malocclusions in the normal skeletal pattern.

Tradition and Innovation in Cataloguing Medieval Manuscripts

2021 ◽  
Vol 139 (1) ◽  
pp. 32-58
Author(s):  
Orietta Da Rold
Keyword(s):  
New Technologies ◽  
New Technology ◽  
Early Career ◽  
Digital Environment ◽  
Digital Form ◽  
Postgraduate Students ◽  
Medieval Manuscripts ◽  
Early Career Researchers ◽  
History Of ◽  
And Training

Abstract In this essay, I offer a brief history of manuscript cataloguing and some observations on the innovations this practice introduced especially in the digital form. This history reveals that as the cataloguing of medieval manuscripts developed over time, so did the research needs it served. What was often considered traditional cataloguing practices had to be mediated to accommodate new scholarly advance, posing interesting questions, for example, on what new technologies can bring to this discussion. In the digital age, in particular, how do digital catalogues interact with their analogue counterparts? What skills and training are required of scholars interacting with this new technology? To this end, I will consider the importance of the digital environment to enable a more flexible approach to cataloguing. I will also discuss new insights into digital projects, especially the experience accrued by the The Production and Use of English Manuscripts 1060 to 1220 Project, and then propose that in the future cataloguing should be adaptable and shareable, and make full use of the different approaches to manuscripts generated by collaboration between scholars and librarians or the work of postgraduate students and early career researchers.

4D Computed Tomography for Dynamic Upper Airway Evaluation in Robin Sequence

2021 ◽  
pp. 019459982110021
Author(s):  
Austin S. Lam ◽  
Michael D. Bindschadler ◽  
Kelly N. Evans ◽  
Seth D. Friedman ◽  
Jeffrey P. Otjen ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Upper Airway ◽  
Quantitative Information ◽  
4D Ct ◽  
Robin Sequence ◽  
Analysis Tools ◽  
Airway Caliber ◽  
4D Computed Tomography ◽  
Ct Data ◽  
Sample Case

Thorough assessment of dynamic upper airway obstruction (UAO) in Robin sequence (RS) is critical, but traditional evaluation modalities have significant limitations. Four-dimensional computed tomography (4D-CT) is promising in that it enables objective and quantitative evaluation throughout all phases of respiration. However, there exist few protocols or analysis tools to assist in obtaining and interpreting the vast amounts of obtained data. A protocol and set of data analysis tools were developed to enable quantification and visualization of dynamic 4D-CT data. This methodology was applied to a sample case at 2 time points. In the patient with RS, overall increases in normalized airway caliber were observed from 5 weeks to 1 year. There was, however, continued dynamic obstruction at all airway levels, though objective measures of UAO did improve at the nasopharynx and oropharynx. Use of 4D-CT and novel analyses provide additional quantitative information to evaluate UAO in patients with RS.

Computed tomography angiography and microsurgical flaps for traumatic wounds: What is the added value?

2021 ◽  
pp. 1-9
Author(s):  
Lucas Sousa Macedo ◽  
Renato Polese Rusig ◽  
Gustavo Bersani Silva ◽  
Alvaro Baik Cho ◽  
Teng Hsiang Wei ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Upper Limb ◽  
Computed Tomography Angiography ◽  
Lower Limb ◽  
High Energy ◽  
Lower Limbs ◽  
Added Value ◽  
Vascular Lesions ◽  
Limb Injuries ◽  
Significant Difference

BACKGROUND: Microsurgical flaps are widely used to treat complex traumatic wounds of upper and lower limbs. Few studies have evaluated whether the vascular changes in preoperative computed tomography angiography (CTA) influence the selection of recipient vessel and type of anastomosis and the microsurgical flaps outcomes including complications. OBJECTIVE: The aim of this study was to evaluate if preoperative CTA reduces the occurrence of major complications (revision of the anastomosis, partial or total flap failure, and amputation) of the flaps in upper and lower limb trauma, and to describe and analyze the vascular lesions of the group with CTA and its relationship with complications. METHODS: A retrospective cohort study was undertaken with all 121 consecutive patients submitted to microsurgical flaps for traumatic lower and upper limb, from 2014 to 2020. Patients were divided into two groups: patients with preoperative CTA (CTA+) and patients not submitted to CTA (CTA–). The presence of postoperative complications was assessed and, within CTA+, we also analyzed the number of patent arteries on CTA and described the arterial lesions. RESULTS: Of the 121 flaps evaluated (84 in the lower limb and 37 in the upper limb), 64 patients underwent preoperative CTA. In the CTA+ group, 56% of patients with free flaps for lower limb had complete occlusion of one artery. CTA+ patients had a higher rate of complications (p = 0.031), which may represent a selection bias as the most complex limb injuries and may have CTA indicated more frequently. The highest rate of complications was observed in chronic cases (p = 0.034). There was no statistically significant difference in complications in patients with preoperative vascular injury or the number of patent arteries. CONCLUSIONS: CTA should not be performed routinely, however, CTA may help in surgical planning, especially in complex cases of high-energy and chronic cases, since it provides information on the best recipient artery and the adequate level to perform the microanastomosis, outside the lesion area.

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