Quantitation of the reconstruction quality of a four-dimensional computed tomography process for lung cancer patients

We have developed a four-dimensional computed tomography (4D CT) technique for mapping breathing motion in radiotherapy treatment planning. A multislice CT scanner (1.5 mm slices) operated in ciné mode was used to acquire 12 contiguous slices in each couch position for 15 consecutive scans (0.5 s rotation, 0.25 s between scans) while the patient underwent simultaneous quantitative spirometry measurements to provide a sorting metric. The spirometry-sorted scans were used to reconstruct a 4D data set. A critical factor for 4D CT is quantifying the reconstructed data set quality which we measure by correlating the metric used relative to internal-object motion. For this study, the internal air content within the lung was used as a surrogate for internal motion measurements. Thresholding and image morphological operations were applied to delineate the air-containing tissues (lungs, trachea) from each CT slice. The Hounsfield values were converted to the internal air content (V). The relationship between the air content and spirometer-measured tidal volume (v) was found to be quite linear throughout the lungs and was used to estimate the overall accuracy and precision of tidal volume-sorted 4D CT. Inspection of the CT-scan air content as a function of tidal volume showed excellent correlations (typically r>0.99) throughout the lung volume. Because of the discovered linear relationship, the ratio of internal air content to tidal volume was indicative of the fraction of air change in each couch position. Theoretically, due to air density differences within the lung and in room, the sum of these ratios would equal 1.11. For 12 patients, the mean value was 1.08 +/- 0.06, indicating the high quality of spirometry-based image sorting. The residual of a first-order fit between v and V was used to estimate the process precision. For all patients, the precision was better than 8%, with a mean value of 5.1% +/- 1.9%. This quantitative analysis highlights the value of using spirometry as the metric in sorting CT scans. The 4D reconstruction provides the CT data required to measure the three-dimensional trajectory of tumor and lung tissue during free breathing.     

Reduced hippocampal insulin-degrading enzyme in late-onset Alzheimer's disease is associated with the apolipoprotein E-epsilon4 allele

Abeta is the major component of amyloid plaques characterizing Alzheimer's disease (AD). Abeta accumulation can be affected by numerous factors including increased rates of production and/or impaired clearance. Insulin-degrading enzyme (IDE) has been implicated as a candidate enzyme responsible for the degradation and clearance of Abeta in the brain. We have previously shown that AD patients exhibit abnormalities in insulin metabolism that are associated with apoliprotein E (APOE) status. The possible association of IDE with AD, as well as the link between APOE status and insulin metabolism, led us to examine the expression of IDE in AD. We report that hippocampal IDE protein is reduced by approximately 50% in epsilon4+ AD patients compared to epsilon4- patients and controls. The allele-specific decrease of IDE in epsilon4+ AD patients is not associated with neuronal loss since neuron-specific enolase levels were comparable between the AD groups, regardless of APOE status. Hippocampal IDE mRNA levels were also reduced in AD patients with the epsilon4 allele compared to AD and normal subjects without the epsilon4 allele. These findings show that reduced IDE expression is associated with a significant risk factor for AD and suggest that IDE may interact with APOE status to affect Abeta metabolism.     

Polycystic Ovary Syndrome and Depression in New Zealand Adolescents

ObjectiveTo determine whether adolescents with polycystic ovary syndrome (PCOS) are more depressed than adolescent girls in the community and to examine factors associated with depression.DesignAn observational study comparing clinical and community samples.SettingTwo specialist reproductive endocrine clinics in Auckland, New Zealand.Participants102 girls aged 14-19 presenting for clinical assessment, fulfilling the Rotterdam consensus for PCOS. The comparison group was 1349 girls from a school-based survey of New Zealand youth.InterventionsClinically significant depression was identified by the long and short form Reynolds Adolescent Depression Scale. BMI, androgen levels, oral contraceptive use, objective symptom severity, age, ethnicity, and socioeconomic grouping were recorded.Main Outcome MeasuresClinically significant depression in the PCOS and community samples. Potential determinants of depression.ResultsClinically significant depression in adolescent girls with PCOS was not increased compared with the community sample (OR 1.3; 95%CI 0.7-2.7, P = .42). Within the PCOS cohort, depression was correlated with increased BMI (P = .01) and possibly acne (P = .08).ConclusionsLean adolescent girls with PCOS did not have more clinically significant depression than girls in the community. Within the PCOS cohort, however, there was a clear association between higher depression scores and elevated BMI. There is a potentially important interaction between obesity and depression in PCOS.     

Accumulation of coronary artery disease risk factors over three years: data from an international inception cohort

OBJECTIVE: To examine the accumulation of risk factors over 3 years in a multicenter, international inception cohort of patients with systemic lupus erythematosus (SLE). METHODS: The Systemic Lupus International Collaborating Clinics registry for atherosclerosis comprises 27 centers from 11 countries. An inception cohort of 935 patients with SLE was assembled, according to a standardized protocol, from 2000 to 2006 to study risk factors for atherosclerosis. Both classic and other coronary artery disease (CAD) risk factors were collected at entry and through 3 years of followup. Therapy was documented over the 3 years. The Framingham 10-year risk factor profile was calculated for each patient at year 1 and year 3. RESULTS: A total of 278 patients from the inception cohort were followed for 3 years and constituted the population for this study. At enrollment a substantial number of patients already demonstrated several risk factors for CAD, both classic and other. All risk factors increased from enrollment over the 3 years of followup. Treatment of hypertension and hypercholesterolemia also increased over 3 years, but less so for hypercholesterolemia. The Framingham 10-year CAD risk profile was higher in men than in women both at entry and at 3 years, and remained unchanged over the 3 years. Corticosteroid use increased only slightly over 3 years, but use of antimalarials and immunosuppressive agents increased to a greater extent. CONCLUSION: Patients with SLE should be monitored for CAD risk factors from the time of diagnosis and appropriate treatment should be instituted early.     

The Diagnosis of Concussion in Pediatric Emergency Departments: A Prospective Multicenter Study

Background

The accurate identification of children with a concussion by emergency physicians is important to initiate appropriate anticipatory guidance and management.

Frailty Assessment Predicts Acute Outcomes in Patients Undergoing Screening Colonoscopy

Background

Colonoscopy is associated with multiple adverse outcomes. With an aging population undergoing colorectal cancer screening, few modalities exist to assess the patient risk prior to colonoscopy. Frailty, the age-related decline in reserve and function across multiple organ systems, predicts poor surgical outcomes, but its role in endoscopy is unclear.

Aims

This prospective cohort study assesses the efficacy of frailty in predicting acute colonoscopy outcomes.

Methods

Participants aged ≥?50 years undergoing screening colonoscopy at a tertiary care center were recruited over 2 months ending in July 2017. Frailty was assessed using a validated 20-s upper-extremity frailty test, which measures the capacity of muscle performance. Demographic data, American Society of Anesthesiologists (ASA) status, and Charlson comorbidity index (CCI) were evaluated. Procedure-related adverse events and cardiopulmonary changes during and in the immediate post-procedure period were recorded. Adverse events were stratified into minor and major events. Chi-square and ANCOVA models were used in the analysis.

Results

Ninety-nine adults (mean age 62.8 years) were enrolled, among which 49 were non-frail and 50 were pre-frail/frail; 50 were female. Overall, 55 participants experienced a total of 87 adverse events. Frailty and ASA status were significantly associated with colonoscopy adverse events (p?=?0.01 and p?=?0.02, respectively). Age and CCI did not predict colonoscopy outcomes.

Conclusions

Compared to age and CCI, frailty status better predicts colonoscopy outcomes in older adults. Among adults undergoing colonoscopy, routine frailty screening should be considered for risk stratification. Additional prospective studies evaluating frailty measurements in endoscopy will further clarify its role in forecasting adverse events.