Interobserver reliability of automated breast volume scanner (ABVS) interpretation and agreement of ABVS findings with hand held breast ultrasound (HHUS), mammography and pathology results

Objectives

Handheld breast ultrasound (HHUS) lacks standardization and reproducibility. The automated breast volume scanner (ABVS) could overcome this limitation. To analyze the interobserver reliability of ABVS and the agreement with HHUS, mammography and pathology is the aim of this study.

Methods

All 42 study participants (=84 breasts) received an ABVS examination in addition to the conventional breast diagnostic work-up. 25 breasts (30%) showed at least one lesion. The scans were interpreted by six breast diagnostic specialists blinded to results of breast imaging and medical history. 32 lesions received histological work-up: 20 cancers were detected. We used kappa statistics to interpret agreement between examiners and diagnostic instruments.

Results

On the basis of the Breast Imaging Reporting and Data System (BI-RADS) classification of the 84 breasts an agreement (defined as ≥4 of 6 examiners) was achieved in 63 cases (75%) (mk = 0.35) and even improved when dichotomizing the interpretation in benign (BI-RADS 1, 2) and suspicious (BI-RADS 4, 5) to 98% (mk = 0.52). Agreement of ABVS examination to HHUS, mammography and pathology was fair to substantial depending on the specific analysis.

Conclusions

The development of an ABVS seems to be a promising diagnostic method with a good interobserver reliability, as well as a comparable good test criteria as HHUS.     

Mental Well‐Being Mediates the Relationship between Perceived Stress and Perceived Health

The association between stress and health has been well researched in the past; however, comparatively few mediators have been tested to understand the underlying mechanism. With increasing awareness on mental well‐being, this study evaluated the relationship between perceived stress and perceived health and examined mental well‐being as a mediator. Two‐hundred undergraduates aged 21 to 26 years completed the English Perceived Stress Scale, Health Status Questionnaire and Asian Mental Well‐Being Scale that assess perceived stress, perceived health and mental well‐being, respectively. Factor analysis and structural equation modelling on the Perceived Stress Scale replicated the reported two‐factor structure after excluding an insignificant item. Linear multiple regression analyses indicated that perceived stress was negatively associated with perceived health. Results showed that mental well‐being partially mediated the relationship between perceived stress and perceived health, although it is acknowledged that this association could be bidirectional. Findings from the present study suggest that future research could focus on reducing stress and improving mental well‐being to alleviate the effect of stress on health. Copyright © 2013 John Wiley & Sons, Ltd.     

Prostate cancer detection upon transrectal ultrasound-guided biopsy in relation to digital rectal examination and prostate-specific antigen level: what to expect in the Chinese population?

We investigated the prostate cancer detection rates upon transrectal ultrasound (TRUS)-guided biopsy in relation to digital rectal examination (DRE) and prostate-specific antigen (PSA), and risk factors of prostate cancer detection in the Chinese population. Data from all consecutive Chinese men who underwent first TRUS-guided prostate biopsy from year 2000 to 2013 was retrieved from our database. The prostate cancer detection rates with reference to DRE finding and PSA level of < 4, 4–10, 10.1–20, 20.1–50 and > 50 ng ml⁻¹ were investigated. Multivariate logistic regression analyses were performed to investigate for potential risk factors of prostate cancer detection. A total of 2606 Chinese men were included. In patients with normal DRE, the cancer detection rates were 8.6%, 13.4%, 21.8%, 41.7% and 85.2% in patients with PSA < 4, 4–10, 10.1–20, 20.1–50 and > 50 ng ml⁻¹ respectively. In patients with abnormal DRE, the cancer detection rates were 12.4%, 30.2%, 52.7%, 80.6% and 96.4% in patients with PSA < 4, 4–10, 10.1–20, 20.1–50 and > 50 ng ml⁻¹ respectively. Older age, smaller prostate volume, larger number of biopsy cores, presence of abnormal DRE finding and higher PSA level were associated with increased risk of prostate cancer detection upon multivariate logistic regression analyses (P < 0.001). Chinese men appeared to have lower prostate cancer detection rates when compared to the Western population. Taking the different risk factors into account, an individualized approach to the decision of TRUS-guided biopsy can be adopted.     

Variance stabilization for computing and comparing grand mean waveforms in MEG and EEG

Grand means of time‐varying signals (waveforms) across subjects in magnetoencephalography (MEG) and electroencephalography (EEG) are commonly computed as arithmetic averages and compared between conditions, for example, by subtraction. However, the prerequisite for these operations, homogeneity of the variance of the waveforms in time, and for most common parametric statistical tests also between conditions, is rarely met. We suggest that the heteroscedasticity observed instead results because waveforms may differ by factors and additive terms and follow a mixed model. We propose to apply the asinh‐transformation to stabilize the variance in such cases. We demonstrate the homogeneous variance and the normal distributions of data achieved by this transformation using simulated waveforms, and we apply it to real MEG data and show its benefits. The asinh‐transformation is thus an essential and useful processing step prior to computing and comparing grand mean waveforms in MEG and EEG.     

Recovery of live virus after storage at ambient temperature using ViveST™

BackgroundA major impediment to performing virological field studies in developing nations is the lack of ultra-low freezers as well as the expense and difficulty of shipping frozen samples. A commercially available product, ViveST?, was developed to preserve nucleic acids at ambient temperature for use in specimen storage and transportation. However, its applications as a viral storage, transport and recovery device have not been evaluated.ObjectiveTo examine the ability of ViveST to preserve live virus following storage at ambient temperature.Study designA panel of six viruses was stored at ambient temperature (～22 °C) in ViveST with fetal bovine serum (FBS), or ViveST with minimal essential media (MEM) and compared with virus stored in universal transport media (M4RT), MEM, and FBS alone. Stored viruses included: human adenovirus (14p), dengue virus 2 (16608), echovirus 3 (Morrisey), human rhinovirus 15 (1734), Coxsackie virus B5 (Faulkner), and herpes simplex virus 1 (HF). After 7 days storage at ambient temperature, virus recovery was measured via titration using viral plaque assays or focus-forming unit assays.ResultsViral titer studies indicate that ViveST with either FBS or M4RT preserved/recovered 5 different viruses for 1 week at ambient temperature. MEM preserved 4 viruses while FBS and ViveST with MEM preserved 3 viruses each. Statistical analyses indicate that M4RT and ViveST with FBS preserved significantly more virus than the other treatments.ConclusionsThese data suggest that ViveST with either FBS or M4RT may be useful in field specimen collection scenarios where ultra-cold storage is not available.