[The relationship between the comprehensive blood inflammation indexes and stage I pneumoconiosis and its combined lung infections].

Objective: To analyze the comprehensive blood inflammation index of the patients with stage I pneumoconiosis complicated with pulmonary infection, and to explore its value in predicting the patients' disease. Methods: In September 2023, 83 patients with stage I pneumoconiosis who were treated in Tianjin Occupational Diseases Precaution and Therapeutic Hospital from November 2021 to August 2023 were selected and divided into non-infected group (56 cases) and infected group (27 cases) according to whether they were combined with lung infection. Workers with a history of dust exposure but diagnosed without pneumoconiosis during the same period were selected as the control group (65 cases) . By referring to medical records and collecting clinical data such as gender, age, occupational history, past medical history, hematology testing, the differences in the comprehensive blood inflammation indexes among the three groups were compared, ROC curve was drawn, and the relationship between comprehensive blood inflammation indexes and stage I pneumoconiosis and its combined lung infection was analyzed. Results: There were significtant differences in the number of neutrophils (N) , the number of lymphocytes (L) , the number of monocytes (M) , C-reactive protein (CRP) , the neutrophil to lymphocyte ratio (NLR) , the monocyte to lymphocyte ratio (MLR) , the platelet to lymphocyte ratio (PLR) , the systemic immune-inflammatory index (SII) , the systemic inflammation response index (SIRI) , the aggregate index of systemic inflammation (AISI) , the derived neutrophil to lymphocyte ratio (dNLR) , the neutrophil to lymphocyte and platelet ratio (NLPR) , and the C-reactive protein to lymphocyte ratio (CLR) (P<0.05) . Compared with the control group, MLR, SIRI and AISI in the non-infected group were significantly increased (P<0.05) . NLR, MLR, PLR, SII, SIRI, AISI, dNLR, NLPR, CLR were significantly increased (P<0.05) . Compared with the non-infected group, NLR, PLR, SII, SIRI, AISI, dNLR, NLPR and CLR were significantly increased in the infected group (P<0.05) . ROC analysis showed that NLR, MLR, PLR, SII, SIRI and AISI had a certain predictive capability for stage I pneumoconiosis (P<0.05) , among which MLR had the highest efficacy, with an AUC of 0.791 (95% CI: 0.710-0.873) , the cut-off value was 0.18, the sensitivity was 71.4%, and the specificity was 78.5%. NLR, MLR, PLR, SII, SIRI, AISI, dNLR, NLPR and CLR all had a certain predictive capability forstage I pneumoconiosis combined lung infection (P<0.05) , among which CLR had the highest efficacy, with an AUC of 0.904 (95%CI: 0.824~0.985) , the cut-off value was 5.33, sensitivity was 77.8%, specificity was 98.2%. Conclusion: The comprehensive blood inflammation index may be an auxiliary predictor of stage I pneumoconiosis and its combined lung infections.

Associations Between Primary Residence and Mental Health in Global Marginalized Populations.

Scholars suggest that marginalized people in non-urban areas experience higher distress levels and fewer psychosocial resources than in urban areas. Researchers have yet to test whether precise proximity to urban centers is associated with mental health for marginalized populations. We recruited 1733 people who reported living in 45 different countries. Participants entered their home locations and completed measures of anxiety, depression, social support, and resilience. Regression and thematic analyses were used to determine what role distance from legislative and urban centers may play in mental health when marginalized people were disaggregated. Greater distance from legislative center predicted higher anxiety and resilience. Greater distance from urban center also predicted more resilience. Thematic analyses yielded five categories (e.g., safety, connection) that further illustrated the impact of geographic location on health. Implications for community mental health are discussed including the need to better understand and further expand resilience in rural areas.

Associations of social cohesion and quality of life with objective and perceived built environments: a latent profile analysis among seniors.

BACKGROUND: Healthy aging requires support from local built and social environments. Using latent profile analysis, this study captured the multidimensionality of the built environment and examined relations between objective and perceived built environment profiles, neighborhood social cohesion and quality of life among seniors. METHODS: In total, 693 participants aged 66-97 were sampled from two US locales in 2005-2008 as part of the Senior Neighborhood Quality of Life Study (SNQLS). Perceived social cohesion and quality of life were assessed using validated surveys. Six objective (geographic information system (GIS)-based) and seven perceived built environment latent profiles generated in previous SNQLS publications were used for analyses. Mixed-effects models estimated social cohesion and quality of life separately as a function of the built environment profiles. RESULTS: More walkable and destination-rich perceived built environment profiles were associated with higher social cohesion and quality of life. Objective built environment profiles were not associated with social cohesion and only positively associated with quality of life in only one locale (Baltimore/DC). CONCLUSIONS: Latent profile analysis offered a comprehensive approach to assessing the built environment. Seniors who perceived their neighborhoods to be highly walkable and recreationally dense experienced higher neighborhood social cohesion and quality of life, which may set the stage for healthier aging.

[Investigate developmental coordination disorder of kindergarten children in Zhejiang Province].

In order to investigate developmental coordination disorder (DCD) of kindergarten children in Zhejiang province, 200 ordinary kindergartens were randomly selected by stratified random sampling in 11 prefecture-level cities of Zhejiang Province, and 38 900 children from 1 000 classes in each grade were then randomly selected into the study from June 2019 to December 2019. The Little DCD Questionnaire and a self-designed questionnaire were used to screen the DCD of those children. There were 36 807 valid questionnaires, and 6.50% (2 391/36 807) of them were positive results. The results showed that boy, age ≤5 years, overweight or obesity, left handedness, comorbidity with motor or developmental disorders and premature infants were risk factors of DCD in children. As for parents and families, maternal gestational age<20 years, maternal overweight or obesity before pregnancy, low-middle level education of parents, direct family and low income of family were also associated with DCD in children. Therefore, it is necessary to conduct early prevention and intervention strategies targeting on identified risk factors among relevant population.

[Research progress on application of laboratory indicators detection of COVID-19].

The outbreak of corona virus disease-19 (corona virus disease-19, COVID-19) caused a huge human disaster from the end of 2019 which is caused by SARS-CoV-2. It will cause damage to multiple organs function in the disease occurrence and development, viral nucleic acid, antibody and serological biochemical immune indicators are mainly indicators of clinical laboratory. The results of these indicators can reflect the organs function of patients and further guide clinical treatment. In this paper, the detection and clinical application of COVID-19 laboratory indicators are reviewed.

[Analysis of clinical diagnosis and treatment in chronic hepatitis B combined with autoimmune hepatitis].

Objective: To summarize the clinical diagnosis and therapeutic method in chronic hepatitis B (CHB) combined with autoimmune hepatitis (AIH). Methods: Clinical manifestations, laboratory examination, imaging, histopathological characteristics, treatment and prognosis of 19 cases diagnosed with CHB combined with AIH followed at the outpatient Department of Gastroenterology of Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine during December 2013 to June 2018 were retrospectively analyzed. Paired sample t-test was used before and after treatment for the measurement of normal distribution data. Measurement data of non-normal distribution were expressed as a median (quartile spacing) and Wilcoxon matched-pairs signed rank test was used before and after treatment. Results: Among the 19 cases, 5 were male and 14 were female. The age of onset was 35 to 63 years, and the average age was 47.10 ± 8.76 years. There were 12 cases diagnosed with CHB before AIH, 5 cases diagnosed with AIH before CHB, and 2 cases diagnosed with AIH and CHB at the same time. After the definite diagnosis of CHB combined with AIH, nucleoside (acid) analogues (antiviral against hepatitis B virus) combined glucocorticoid therapy were given, and azathioprine or mycophenolate mofetil (immunosuppressant) was added according to the intrahepatic inflammation (inflammation graded at G3 and above) and leukocyte conditions. The duration of treatment varied between 2 weeks to 16 (median treatment duration of 6 weeks), except for one case who was just diagnosed and followed up. Biochemical indicators and immunoglobulin of the remaining 18 cases before and after treatment was significantly decreased, and the differences were statistically significant (P < 0.05), with HBV DNA < 20 copies/ml. Conclusion: CHB combined with AIH diagnosis can be easily missed. Therefore, it requires comprehensive diagnosis combined with clinical characteristics, autoantibodies, and immunoglobulin levels with special emphasis on pathological characteristics of liver tissue. Anti-HBc-positive patients using immunosuppressant should be carefully monitored for HBV DNA and anti-HBV treatment should be given if necessary.

[Study on binding kinetics profiles of tea polyphenols-α-glucosidase interaction].

The combination index(CI) method was used to evaluate the combination inhibition mechanism of epicatechin gallate(ECG) and other tea polyphenols [epigallocatechin gallate(EGCG) and gallocatechin gallate(GCG)] on α-glucosidase. Herein, using ECG as research object, the surface plasmon resonance(SPR) analysis were employed to study the binding affinities and kinetic parameters of three tea polyphenols components on α-glucosidase, respectively. The concentration-time curve mathematical model of the drug in the unstirred water layer(the adjacent region of α-glucosidase) established previously by our group was used to evaluate the concentration-time curves of the tea polyphenols in the α-glucosidase vicinity. The prediction model of drug-α-glucosidase binding kinetics established by our group was used to evaluate the dynamic process of drug-α-glucosidase binding kinetics of different oral administration processes of ECG. Using acarbose as a reference, the accuracy of the model prediction was judged based on the difference between the prediction results and the actual clinical performance. Using the mathematical model of drug-α-glucosidase interaction, the drug-α-glucosidase binding kinetic characteristic curves of ECG in different administration processes were obtained, which indirectly proved that the synergistic effect of multi-component combination of traditional Chinese medicine and the clinical characteristics of repeat administration were scientific and reasonable.

Phase Space Dynamics of a Plasma Wakefield Dechirper for Energy Spread Reduction.

Plasma-based accelerators have made impressive progress in recent years. However, the beam energy spread obtained in these accelerators is still at the ∼1% level, nearly one order of magnitude larger than what is needed for challenging applications like coherent light sources or colliders. In plasma accelerators, the beam energy spread is mainly dominated by its energy chirp (longitudinally correlated energy spread). Here we demonstrate that when an initially chirped electron beam from a linac with a proper current profile is sent through a low-density plasma structure, the self-wake of the beam can significantly reduce its energy chirp and the overall energy spread. The resolution-limited energy spectrum measurements show at least a threefold reduction of the beam energy spread from 1.28% to 0.41% FWHM with a dechirping strength of ∼1 (MV/m)/(mm pC). Refined time-resolved phase space measurements, combined with high-fidelity three-dimensional particle-in-cell simulations, further indicate the real energy spread after the dechirper is only about 0.13% (FWHM), a factor of 10 reduction of the initial energy spread.

Visible light communication using dual camera on one smartphone.

Dual camera is becoming increasingly prevalent among smartphone camera schemes these days. This paper demonstrates a system prototype by using the color and monochrome cameras on one smartphone simultaneously for visible light communication. To achieve this, we propose a novel dual-modulation scheme. The baseband signal is firstly modulated by color ratio modulation-color shift keying (CRM-CSK) to broadcast color ratio information that can be distinguished by the color camera. Next to it, gray level modulation (GLM) is utilized to generate CRM symbols with gray levels that can be distinguished by the monochrome camera. Our experiment shows a significant improvement in the downlink data rate of the optical camera communication (OCC) using a single light source.

Apparent diffusion coefficient measurement in luminal breast cancer: will tumour shrinkage patterns affect its efficacy of evaluating the pathological response?

AIM: To determine which region of interest (ROI) placement method of apparent diffusion coefficient (ADC) measurement has the best performance for predicting pathological complete response (PCR) at two cycles of neoadjuvant chemotherapy (NAC) according to different tumour shrinkage patterns of luminal breast cancer and to assess the evaluative accuracy of ADC value combined with other clinicopathological indicators. MATERIALS AND METHODS: Sixty-one patients who underwent NAC for histopathologically confirmed breast cancer were enrolled in this retrospective study. The ADC values of different shrinkage patterns (concentric shrinkage, nest or dendritic shrinkage, and mixed shrinkage) for tumours shown by diffusion-weighted imaging (DWI) were measured independently using three ROI placement methods (single-round, three-round, and freehand). Intraclass correlation coefficients (ICCs) were used to assess the interobserver variability in the ADC values. Multivariate logistic regression analysis was performed to identify the independent predictors of PCR. RESULTS: The best placement method found was single-round ROI in all the patients (AUC=0.863). When analysed separately, the effectiveness results differed: the single-round method was optimal for concentrically shrinking tumours (AUC=0.970); the freehand method was optimal for nest or dendritically shrinking tumours (AUC=0.714); and the three-round method was optimal for mixed shrinking tumours (AUC=0.975). Multivariate logistic analysis showed that oestrogen receptor (ER), ΔADC% and tumour diameter reduction (ΔD%) were independent factors in evaluating the PCR. CONCLUSION: The methods for measuring ADC values vary across different shrinkage patterns of luminal tumours. ΔADC%, ER and ΔD% were independent factors for evaluating the PCR.

Utility of apparent diffusion coefficient as an imaging biomarker for assessing the proliferative potential of invasive ductal breast cancer.

AIM: To determine the clinical utility of apparent diffusion coefficient (ADC) metrics for the non-invasive assessment of tumour proliferation indicated by Ki-67 labelling index (LI) in invasive ductal breast cancer. MATERIALS AND METHODS: Eighty patients with 80 histopathologically proven invasive ductal breast cancers underwent diffusion-weighted imaging with b-values of 0 and 800 s/mm2 at a 3-T system. ADC metrics including ADCmean, ADCmedian, ADCmin, ADCmax, and ΔADC (ADCmax-ADCmin) were recorded from the entire tumour volume on ADC maps, and correlated with the Ki-67 LI. Ki-67 staining of ≥14% was considered to indicate high proliferation and <14% was considered to indicate low proliferation. RESULTS: ADCmin, ADCmax, and ΔADC showed significant correlations with the Ki-67 LI (for all tumours, r=-0.311, 0.436, and 0.551, respectively; for luminal/human epidermal growth factor receptor 2 (HER2)-negative group, r=-0.437, 0.512, and 0.639, respectively; all p<0.01), whereas ADCmean and ADCmedian showed no significant correlation (both p>0.05). Receiver operating characteristic (ROC) curve analysis for the differentiation of high- from low-proliferation groups showed that ΔADC yielded the highest area under the ROC curve for the whole tumour population (0.825; 95% confidence interval [CI]: 0.724, 0.901), as well as for the luminal/HER2-negative group (0.844; 95% CI: 0.692, 0.940). CONCLUSION: ΔADC may serve as a promising imaging biomarker for the prediction of Ki-67 proliferation status in invasive ductal breast cancer.

CRISPR/Cas9-mediated MSTN disruption and heritable mutagenesis in goats causes increased body mass.

Genetic engineering in livestock has been greatly enhanced through the use of artificial programmed nucleases such as the recently emerged clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system. We recently reported our successful application of the CRISPR/Cas9 system to engineer the goat genome through micro-injection of Cas9 mRNA and sgRNAs targeting MSTN and FGF5 in goat embryos. The phenotypes induced by edited loss-of-function mutations of MSTN remain to be evaluated extensively. We demonstrate the utility of this approach by disrupting MSTN, resulting in enhanced body weight and larger muscle fiber size in Cas9-mediated gene-modified goats. The effects of genome modifications were further characterized by H&E staining, quantitative PCR, Western blotting and immunofluorescence staining. Morphological and genetic analyses indicated the occurrence of phenotypic and genotypic modifications. We further provide sufficient evidence, including breeding data, to demonstrate the transmission of the knockout alleles through the germline. By phenotypic and genotypic characterization, we demonstrated the merit of using the CRISPR/Cas9 approach for establishing genetically modified livestock with an enhanced production trait.

[Effect of lipid-induced macrophage M1/M2 polarization on lipid metabolism in hepatocytes].

Objective: This study aims to explore the effect of lipid-induced macrophage M1/M2 polarization on lipid metabolism in hepatocytes. Methods: RAW264.7 macrophages were incubated with different kinds of fatty acids including saturated fatty acids-palmitic acid (PA), monounsaturated fatty acids-oleic acid (OA) and polyunsaturated fatty acids-docosahexaenoic acid (DHA), and cell culture supernatants were collected to prepare conditioned medium (CM). Hepatocytes were isolated by in situ perfusion of the liver with collagenase in mice, and a macrophage-hepatocyte CM co-culture system was established. Macrophage M1/M2 phenotype markers were detected by Real-time PCR. Lipid synthesis and decomposition related mRNA and protein expressions in hepatocytes were detected by Real-time PCR and Western Blot. Lipid depositions in hepatocytes were detected by oil red O staining. An analysis of variance was used for comparison of means between multiple groups. Results: Compared with control groups, PA polarized macrophages to a M1 phenotype (expression of TNF-α and IL-6 significantly increased, F≥22.68, P < 0.01), OA polarized macrophages to a M1/M2 mixed phenotype (expression of IL-6, Mrc2 and IL-10 increased F≥4.94, P < 0.05) and DHA polarized macrophages to a M2 phenotype (expression of Mrc2 and IL-10 significantly increased, F≥4.94, P < 0.01). CM-PA significantly increased lipid synthesis related genes, including SREBP1C, ACC1 mRNA expression (F≥5.66, P < 0.01) and FASN, ACC1 protein expression (F≥38.34, P < 0.05) in hepatocytes, and decreased lipid decomposition gene ACOX1 protein expression (F=154.48, P < 0.01). CM-OA affected several lipid metabolism genes expression. CM-DHA significantly increased CPT1A mRNA expression (F = 10.30, P < 0.01) and ACOX1, CPT1A protein expression (F≥47.06, P < 0.05), and decreased SREBP1C, ACC1 protein expression (F≥65.84, P < 0.05) in hepatocytes. Massive lipid droplets were deposited in hepatocytes in CM-PA treated hepatocytes, and a few amount of lipid droplets were deposited in CM-DHA treated hepatocytes. Conclusion: Different fatty acids affect the balance of lipid metabolism in hepatocytes and liver by inducing macrophage M1 / M2 polarization, thus promoting or delaying the progression of non-alcoholic fatty liver disease.

Femtosecond Probing of Plasma Wakefields and Observation of the Plasma Wake Reversal Using a Relativistic Electron Bunch.

We show that a high-energy electron bunch can be used to capture the instantaneous longitudinal and transverse field structures of the highly transient, microscopic, laser-excited relativistic wake with femtosecond resolution. The spatiotemporal evolution of wakefields in a plasma density up ramp is measured and the reversal of the plasma wake, where the wake wavelength at a particular point in space increases until the wake disappears completely only to reappear at a later time but propagating in the opposite direction, is observed for the first time by using this new technique.

Karyotype analysis in large sample cases from Shenyang Women's and Children's hospital: a study of 16,294 male infertility patients.

To explore that it is necessary to routinely detect chromosomes in infertile patients, we investigated peripheral blood lymphocyte karyotype in 16,294 male infertile patients in the north-east of China and analysed the incidence and type of chromosomal anomaly and polymorphism. G-banding karyotype analysis of peripheral blood lymphocytes was performed in 16,294 cases. Semen analysis was performed three times in all the men. PCR and FISH confirmed the presence of the SRY gene. The rate of chromosomal anomaly in the 16,294 male infertile patients was 4.15% (677/16,294). The rates of chromosomal anomaly were 0.24% in normal semen group, 12.6% in light oligoasthenospermia group, 4.7% in moderate-to-severe oligoasthenospermia group and 9.59% in azoospermia group. There are two male infertile patients with 45,X chromosome karyotype. One X male patient had confirmed the presence of the SRY gene and FISH analysis demonstrated its location on the p arm of chromosome 13. The other X male patient had not found SRY gene in its whole-genome DNA. Meanwhile, sperm motility is slightly oligo-asthenozoospermic at the age of 35-39 and nearly azoospermic at the age of 40-45. As the rates of chromosomal anomaly are 0.24% and 12.6% even in normal semen group and light oligoasthenospermia group, the rates of chromosomal polymorphism are 5.36% and 25.51% in normal semen group and light oligoasthenospermia group, respectively; it is necessary to explore peripheral blood lymphocyte karyotype in all infertile couples. We mentioned that Y, 1, 2, 9 and 12 chromosomes were quite important about male infertility. These findings demonstrate that autosomal retention of SRY can be submicroscopic and emphasise the importance of PCR and FISH in the genetic workup of the monosomic X male. At the same time, it suggested that male infertility might be related to meiotic disturbances with spermatogenetic arrest in Y-autosome translocations, which could result in infertility by reduction of sperm production. Last but not least, ageing is one of the factors that could reduce sperm motility and quality.

[A retrospective analysis of clinical characteristics and outcomes of heart failure patients with different left ventricular ejection fractions].

Objective: To compare the clinical characteristics, and outcomes of patients with heart failure with different left ventricular ejection fractions (LVEF). Methods: A total of 1 182 hospitalized patients with heart failure (HF) were enrolled and retrospectively studied in the present study. The patients were stratified by LVEF as reduced (HFrEF, LVEF<40%, n=313), mid-range (HFmrEF, 40% ≤LVEF <50%, n=287) and preserved (HFpEF, LVEF≥50%, n=582) ejection fraction groups. Among the 1 182 cases, 941 of them (81.3%, 84.9%, and 84.0% inHFrEF, HFmrEF and HFpEF groups, respectively) were followed up for an median duration of 27.3 months. Results: (1) Among the study patients, 26.5% were in HFrEF, 24.3% in HFmrEF, and 49.2% in HFpEF groups. (2) Ischemic heart disease with HFmrEF was more frequent than that in patients with HFrEF. The average age, percentage of female subjects, systolic blood pressure, uric acid, N terminal B-type natriuretic peptide precursor (NT-proBNP), hemoglobin, and the incidence of hypertensive heart disease, anemia, atrial fibrillation in patients with HFmrEF were higher than those in patients with HFrEF, but lower than those in patients with HFpEF (all P<0.01). (3) The all-cause cumulative mortality was 10.8% at 1 year, 20.6% at 2 years and 35.9% at 5 years. No difference was observed in the all-cause cumulative mortality at 1 year, 2 years, 5 years among the three groups (all P>0.05). Conclusions: The HFmrEF patients, as a new and distinct group, were with many intermediate characteristics compared with HFrEF and HFpEF subjects. However, the all-cause mortality was not significantly different among HF patients with different LVEF.

Nanoscale Electron Bunching in Laser-Triggered Ionization Injection in Plasma Accelerators.

Ionization injection is attractive as a controllable injection scheme for generating high quality electron beams using plasma-based wakefield acceleration. Because of the phase-dependent tunneling ionization rate and the trapping dynamics within a nonlinear wake, the discrete injection of electrons within the wake is nonlinearly mapped to a discrete final phase space structure of the beam at the location where the electrons are trapped. This phenomenon is theoretically analyzed and examined by three-dimensional particle-in-cell simulations which show that three-dimensional effects limit the wave number of the modulation to between >2k_{0} and about 5k_{0}, where k_{0} is the wave number of the injection laser. Such a nanoscale bunched beam can be diagnosed by and used to generate coherent transition radiation and may find use in generating high-power ultraviolet radiation upon passage through a resonant undulator.

Physical Mechanism of the Transverse Instability in Radiation Pressure Ion Acceleration.

The transverse stability of the target is crucial for obtaining high quality ion beams using the laser radiation pressure acceleration (RPA) mechanism. In this Letter, a theoretical model and supporting two-dimensional (2D) particle-in-cell (PIC) simulations are presented to clarify the physical mechanism of the transverse instability observed in the RPA process. It is shown that the density ripples of the target foil are mainly induced by the coupling between the transverse oscillating electrons and the quasistatic ions, a mechanism similar to the oscillating two stream instability in the inertial confinement fusion research. The predictions of the mode structure and the growth rates from the theory agree well with the results obtained from the PIC simulations in various regimes, indicating the model contains the essence of the underlying physics of the transverse breakup of the target.

Physics of Phase Space Matching for Staging Plasma and Traditional Accelerator Components Using Longitudinally Tailored Plasma Profiles.

Phase space matching between two plasma-based accelerator (PBA) stages and between a PBA and a traditional accelerator component is a critical issue for emittance preservation. The drastic differences of the transverse focusing strengths as the beam propagates between stages and components may lead to a catastrophic emittance growth even when there is a small energy spread. We propose using the linear focusing forces from nonlinear wakes in longitudinally tailored plasma density profiles to control phase space matching between sections with negligible emittance growth. Several profiles are considered and theoretical analysis and particle-in-cell simulations show how these structures may work in four different scenarios. Good agreement between theory and simulation is obtained, and it is found that the adiabatic approximation misses important physics even for long profiles.

Analysing breast tissue composition with MRI using currently available short, simple sequences.

AIM: To determine the most robust commonly available magnetic resonance imaging (MRI) sequence to quantify breast tissue composition at 1.5 T. MATERIALS AND METHODS: Two-dimensional (2D) T1-weighted, Dixon fat, Dixon water and SPAIR images were obtained from five participants and a breast phantom using a 1.5 T Siemens Aera MRI system. Manual segmentation of the breasts was performed, and an in-house computer program was used to generate signal intensity histograms. Relative trough depth and relative peak separation were used to determine the robustness of the images for quantifying the two breast tissues. Total breast volumes and percentage breast densities calculated using the four sequences were compared. RESULTS: Dixon fat histograms had consistently low relative trough depth and relative peak separation compared to those obtained using other sequences. There was no significant difference in total breast volumes and percentage breast densities of the participants or breast phantom using Dixon fat and 2D T1-weighted histograms. Dixon water and SPAIR histograms were not suitable for quantifying breast tissue composition. CONCLUSION: Dixon fat images are the most robust for the quantification of breast tissue composition using a signal intensity histogram.