Practitioner compression force variability in mammography: a preliminary study.
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ABSTRACT:
SUBMITTER: Mercer CE
PROVIDER: S-EPMC3608044 | biostudies-other | 2013 Feb
REPOSITORIES: biostudies-other
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Project description:ObjectivesTo reduce pain and discomfort associated with breast compression in mammography, a pressure-controlled compression paddle was recently introduced. The objective was to evaluate the pressure-controlled paddle by comparing it to the standard force-controlled paddle.MethodsDifferences of compressed breast thickness (CBT), compression force, compression pressure, and average glandular dose (AGD) between annual follow-up full-field digital mammography exams of 3188 patients were retrospectively examined. Two groups were compared: (1) force-force group (FF-group), both examinations were performed with the force-controlled paddle, and (2) force-pressure group (FP-group), only the follow-up examination was performed with the pressure-controlled paddle. In an additional group of patients, pain scores on a scale of 0 (no pain at all) to 10 (worst pain imaginable) were evaluated prospectively (n?=?343) who were randomly assigned to either paddle.ResultsMedian differences between follow-up exams in CBT, compression force, compression pressure, and AGD were for the FF- and FP-group respectively -?1.0 vs 0.0 mm (p?<?0.001); 0.0 vs?-?1.0 daN (p?=?0.002); -?1.0 vs -?0.5 kPa (p?=?0.005); and 0.05 vs -?0.02 mGy (p?<?0.001). These differences were, although statistically significant, clinically non-relevant (defined as ?CBT >?±?2 mm; ?force >?±?2 daN; ?pressure >?±?1 kPa and ?AGD >?±?0.1 mGy). The subanalysis dividing CBT into five categories revealed similar results. The median [interquartile range] pain scores were 6 [3, 7] and 5 [3, 7] for the force-controlled and pressure-controlled paddle, respectively, which was not significantly different (p?=?0.113).ConclusionsWe observed no clinically relevant differences in CBT, compression force, compression pressure, AGD, or pain score between the force- and pressure-controlled paddle. As such, we found no basis for preferring one paddle over the other.Key points• The pressure-controlled paddle did not show any clinically relevant changes in breast compression parameters compared to the force-controlled paddle. • The pressure-controlled paddle did not lead to significant reduction in pain scores indicated by the patients compared to the force-controlled paddle. • A large variation in compression force and compression pressure was observed in mammography exams for the both the force- and pressure-controlled compression paddle.
| S-EPMC6443616 | biostudies-literature
Project description:Mammography can be painful and unpleasant, but effective interventions to improve the experience remain scarce. As a first step towards more effective interventions, we aimed to achieve a thorough, contemporary understanding of thoughts, feelings and behaviours which affect and arise from mammography experiences. Research and professional experience suggest that the interaction between client and practitioner may be paramount in determining the quality of a client's experience. Therefore, this study aimed to capture the perspectives of clients and mammography staff from UK breast screening programmes. Thematic analysis of semi-structured qualitative in-depth interviews with 22 clients and 18 staff revealed that clients had positive attitudes to breast screening and mostly low knowledge about potential harms. Staff data indicated that some women attend for breast screening under pressure from others. Pain and coping with it were prominent themes, with wide variations in pain experiences. Clients recognised differences in mammographers' abilities to put them at ease. Staff difficulties included empowering clients within the confines of a taxing technique, and maintaining compassionate care when under strain. Future intervention development should focus on the information and support needs of women prior to the appointment and on effectively training and supporting mammographers to deal with challenging encounters.
| S-EPMC5484333 | biostudies-literature
Project description:Importance:Many women dread undergoing mammography, and some may not attend or reattend breast cancer screening because of the discomfort or pain induced by breast compression. Objective:To evaluate the noninferiority of the self-compression mammography technique for reducing breast thickness compared with standard compression. Design, Setting, and Participants:This prospective, parallel-group, noninferiority randomized clinical trial was conducted from May 7, 2013, to October 26, 2015, at 6 cancer care centers in France. Participants were women aged 50 to 75 years, without a history of recent breast surgical procedure or treatment, and who could perform self-compression. Analyses were performed on intention-to-treat basis from January 27, 2017, to March 30, 2018. Interventions:Patients were randomized 1:1 to the self-compression group or the standard compression group. Main Outcomes and Measures:Primary end point was breast thickness expressed as the mean of 4 views: right and left craniocaudal and right and left mediolateral oblique. The predefined noninferiority margin was a difference of 3 mm, with a 1-sided 95% CI. Secondary end points included compression force, image quality, requirement for additional views, pain, and patient satisfaction and radiographer assessment questionnaires. Results:Among the 549 women randomized, 548 (97.3%) completed the trial. Of these, 275 (48.8%) (mean [SD] age, 61.35 [6.34] years) were randomized to the self-compression arm and 273 (48.5%) (mean [SD] age, 60.84 [6.41] years) to the standard compression arm. The difference in the mean thickness between the 2 arms was lower than the noninferiority margin, with an upper 1-sided 95% CI less than 3 mm (-0.17; 95% CI,-∞ to 1.89 mm; P < .05). Compression force was higher in the self-compression group compared with the standard compression arm for the 4 mammographic views. Pain was statistically significantly lower in the self-compression group (n = 274) compared with the standard compression group (n = 269) (median [interquartile range (IQR)] score, 2 [1-5] vs 3 [1-5]; P = .009). No difference was reported in the image quality scores of the 2 groups or in the number of additional views performed (median [IQR] extra views, 2 [2-2] vs 2 [2-3] extra views; P = .64), whatever the indication, including insufficient image quality (29 [16.8%] vs 27 [15.0%] insufficient quality views; P = .65). No adverse effects or pain were reported by the participants after the self-compression mammography. Conclusions and Relevance:Self-compression does not appear to be inferior to standard compression mammography in achieving minimal breast thickness without increasing pain or compromising image quality; this technique may be an effective option for women who want to be involved in their breast examination. Trial Registration:ClinicalTrials.gov identifier: NCT02866591.
| S-EPMC6440229 | biostudies-literature
Project description:BackgroundCine-magnetic resonance imaging (MRI) is currently used in real-time tumor tracking during magnetic resonance (MR)-guided radiotherapy. As a type of MRI specified for motion tracking, a few minutes' acquisition results in thousands of 2-dimensional (2D) images. For MR-guided radiotherapy consisting of multiple treatment fractions, the large number of cine-MRI images would be disproportionate to the tight clinical data storage available. To alleviate this issue, the feasibility of compression of cine-MRI via video encoders was investigated in this study.MethodsThe cine-MRI images were first sorted into 3 sequences according to their plane orientations. Then, each sequence was reordered according to their acquisition times [time-based (TB)] or content similarities [similarity-based (SB)]. As a result, 3 sequences were obtained for 3 plan orientations. Next, the obtained sequences were processed by a video encoder and the corresponding 3 video files were achieved. We employed 3 popular video encoders: Motion JPEG (M-JPEG), Advanced Video Coding (AVC), and High Efficiency Video Coding (HEVC). The performances of the sequence reordering methods and video encoders were evaluated based on a total of 150 image sets.ResultsThe mean correlation quantities for SB sequences were higher than those for TB sequences by 3% (sagittal), 2% (coronal), and 1% (transverse), respectively. The average compression ratio (CR) yielded by the SB sequences was higher than that achieved by the TB sequences. Comparing with M-JPEG, the CRs obtained by AVC and HEVC were increased by 58% and 62% (sagittal), 16% and 23% (coronal), and 48% and 56% (transverse), respectively. Among the 3 video encoders, the highest CRs and restoration accuracy were achieved by HEVC.ConclusionsHEVC with inter-frame coding is more effective in reducing the redundant information in consecutive images. It is feasible to implement the video encoder for high-performance cine-MRI compression.
| S-EPMC10722010 | biostudies-literature
Project description:The force-vector theory contends that horizontal exercises are more specific to horizontal sports skills. In this context, the focus is on horizontal force production relative to the global coordinate frame. However, according to the principle of dynamic correspondence, the direction of force relative to the athlete is more important, and thus the basis for the force-vector theory is flawed. The purpose of this study was therefore to test the force-vector theory. According to the force-vector theory, hip thrust is a horizontally loaded exercise, and so hip thrust training would be expected to create greater improvements in horizontal jump performance than vertical jump performance. Eleven collegiate female athletes aged 18⁻24 years completed a 14-week hip thrust training programme. Pre and post testing was used to measure the following: vertical squat jump, vertical countermovement jump, horizontal squat jump, horizontal countermovement jump and hip thrust 3 repetition maximum (3RM). Subjects improved their 3 repetition maximum hip thrust performance by 33.0% (d = 1.399, p < 0.001, η² = 0.784) and their vertical and horizontal jump performance (improvements ranged from 5.4⁻7.7%; d = 0.371⁻0.477, p = 0.004, η² = 0.585). However, there were no differences in the magnitude of the improvement between horizontal and vertical jumping (p = 0.561, η² = 0.035). The results of this study are contrary to the predictions of the force-vector theory. Furthermore, this paper concludes with an analysis of the force-vector theory, presenting the mechanical inconsistencies in the theory. Coaches should use the well established principle of dynamic correspondence in order to assess the mechanical similarity of exercises to sports skills.
| S-EPMC6409580 | biostudies-other
Project description:Competition is a major determinant of plant community structure consisting of both species-specific and general interactions, either of which may influence competitive competency and plant abundance and size. In certain cases, competitive competency could arise from altered gene expression and plant function when an individual is confronted with new competitors. We explored competition at the molecular level by hybridizing transcripts from Centaurea maculosa (spotted knapweed), one of North America's most invasive exotic plant species, to an Arabidopsis microarray chip. Centaurea was grown in competition with Festuca idahoensis (Idaho fescue), a native grass species that generally has weak competitive effects against Centaurea; Gaillardia aristata (Indian blanketflower), a native herbaceous species that tends to be a much stronger competitor against Centaurea; or alone (control). The expression of some genes was found to be relatively uninfluenced by the type of plant neighbor, whereas other patterns of gene expression appeared to be more neighbor specific. To our knowledge, these results are the first to identify genes in an invasive plant that are induced or repressed by plant neighbors and provide a new avenue of insight into the molecular aspects of plant competitive ability. Keywords: treated vs.untreated
2008-10-31 | GSE7443 | GEO
Project description:Competition is a major determinant of plant community structure consisting of both species-specific and general interactions, either of which may influence competitive competency and plant abundance and size. In certain cases, competitive competency could arise from altered gene expression and plant function when an individual is confronted with new competitors. We explored competition at the molecular level by hybridizing transcripts from Centaurea maculosa (spotted knapweed), one of North America's most invasive exotic plant species, to an Arabidopsis microarray chip. Centaurea was grown in competition with Festuca idahoensis (Idaho fescue), a native grass species that generally has weak competitive effects against Centaurea; Gaillardia aristata (Indian blanketflower), a native herbaceous species that tends to be a much stronger competitor against Centaurea; or alone (control). The expression of some genes was found to be relatively uninfluenced by the type of plant neighbor, whereas other patterns of gene expression appeared to be more neighbor specific. To our knowledge, these results are the first to identify genes in an invasive plant that are induced or repressed by plant neighbors and provide a new avenue of insight into the molecular aspects of plant competitive ability. Keywords: treated vs.untreated First file, Chip 508 (9-9-05) is preliminary hyb data to see if this cross species hybridization is possible using the OAR27K chip Experiment 1 (chip 508): The Arabidopsis OAR27K gene chip was hybridized with labeled cDNA probes produced from samples of Centaurea RNA at the W.M. Keck Foundation Biotechnology Resource Laboratory, Yale University. The OAR27K gene chip consists of 70-mer oligos representing approximately 27,000 genes from Arabidopsis. Leaf and root samples were reverse-transcribed into cDNA and labeled with different fluorescent dyes (Cy3 and Cy5) using the Genisphere Array 900 kit (Cat No.W500180) (Genisphere, Hatfield PA). Labeled cDNAs were hybridized to the OAR27Kchip using the Advalytix ArrayBooster DNA Microarray Incubator (Advalytix, Boston MA). Approximately 10ug of each sample was used for hybridization.Experiment 2: Hybridization and labeling followed the procedure above, except the experimental control was Centaurea plants grown alone, and the test situations were Centaurea grown with Gaillardia or Festuca neighbors. In each experiment, RNA from Centaurea grown alone was used as the control (labeled with Cy3) and RNA from Centaurea grown with a neighbor was used as the test (labeled with Cy5). Two replicates were performed for each test situation.
2010-05-17 | E-GEOD-7443 | biostudies-arrayexpress
Project description:We measured the amount of bite force generated by patients treated for parasymphyseal fractures of the mandible by open reduction and internal fixation at various predetermined time intervals. Sixty volunteers ranging from 18 to 60 years old were selected as the control group. All measurements were made on a bite force measurement device with the head in an upright position and in an unsupported natural position. Bite forces were measured at the incisor and right and left molar regions. These bite forces were compared with six patients with isolated mandibular unilateral parasymphyseal fractures. All patients were operated using open reduction and internal fixation using two miniplates at the fracture site. In the volunteer group, bite forces ranged from 22 to 50 kg in the molar region and 3 to 27 kg in the incisor region. Mean adult healthy values (male and female) in the molar region were 36 kg and in the incisor region, 15 kg. In mandibular parasymphyseal fractures, incisor bite forces were reduced significantly when compared with the control group in the first 2 postoperative weeks and regained significantly thereafter till 4 to 6 weeks. Bite forces in the molar region took ~6 to 12 weeks to regain maximum bite forces when compared with the volunteer group. Restoration of functional bite forces was evident by 6 to 8 weeks. However, the restoration of maximum bite forces may require up to 12 weeks in parasymphyseal fractures.
| S-EPMC3314259 | biostudies-other
Project description:Patients with suspected deep vein thrombosis (DVT) of the lower limb represent a diagnostic dilemma for general practitioners. Compression ultrasonography (US) is universally recognized as the best test of choice. We assessed the diagnostic accuracy of compression US performed by general practitioners given short training in the management of symptomatic proximal DVT.From May 2014 to May 2016, we evaluated in a multicenter, prospective cohort study all consecutive outpatients with suspected DVT; bilateral proximal lower limb compression US was performed by general practitioners and by physicians expert in vascular US, each group blinded to the other's findings. In all examinations with a negative or nondiagnostic result, compression US was repeated by the same operator after 5 to 7 days. Inter-observer agreement and accuracy were calculated.We enrolled a total of 1,107 patients. The expert physicians diagnosed DVT in 200 patients, corresponding to an overall prevalence of 18.1% (95% CI, 15.8%-20.3%). The agreement between the trained general practitioners and the experts was excellent (Cohen ? = 0.86; 95% CI, 0.84-0.88). Compression US performed by general practitioners had a sensitivity of 90.0% (95% CI, 88.2%-91.8%) and a specificity of 97.1% (95% CI, 96.2%-98.1%) with a diagnostic accuracy for DVT of 95.8% (95% CI, 94.7%-97.0%).Our results suggest that, even in hands of physicians not expert in vascular US, compression US can be a reliable tool in the diagnosis of DVT. We found that the sensitivity achieved by general practitioners appeared suboptimal, however, so future studies should evaluate the implementation of proper training strategies to maximize skill.
| S-EPMC5683865 | biostudies-literature
Project description:In this study, we evaluated and compared the morphogenetic variability and the degree of recessive homozygosity in patients with manifested ischemic stroke compared to healthy controls. We have evaluated 120 patients with manifested ischemic stroke, of which 64 did not have hypertension and 56 have hypertension. For comparison, we additionally tested 194 healthy individuals without manifested ischemic stroke (controls). For the estimation of the degree of recessive homozygosity, we have performed the homozygously recessive characteristics (HRC) test and tested 19 HRCs. There was a significant difference in the individual variations of 19 HRCs between the controls and patients with manifested ischemic stroke (∑χ² = 60.162, p < 0.01). The mean values of the tested HRCs significantly differed between the controls and group with manifested ischemic stroke (Controls − 5.71 ± 1.61, Ischemic stroke group − 6.25 ± 1.54, p = 0.012). For the tested individuals with hypertension, the mean values of HRCs did not significantly differ between the controls and those that had manifested ischemic stroke (Controls − 5.28 ± 1.75, Ischemic stroke group − 5.64 ± 1.48, p = 0.435). We found a significant difference in the frequencies of HRCs between those with and without hypertension for controls (p < 0.003) and for those with manifested ischemic stroke (p < 0.001). There are increased degrees of recessive homozygosity along with decreased variability in patients with manifested ischemic stroke compared to controls.
| S-EPMC6068471 | biostudies-literature