MRS thermometry calibration at 3 T: effects of protein, ionic concentration and magnetic field strength

MRS thermometry has been utilized to measure temperature changes in the brain, which may aid in the diagnosis of brain trauma and tumours. However, the temperature calibration of the technique has been shown to be sensitive to non-temperature-based factors, which may provide unique information on the tissue microenvironment if the mechanisms can be further understood. The focus of this study was to investigate the effects of varied protein content on the calibration of MRS thermometry at 3 T, which has not been thoroughly explored in the literature. The effects of ionic concentration and magnetic field strength were also considered. Temperature reference materials were controlled by water circulation and freezing organic fixed-point compounds (diphenyl ether and ethylene carbonate) stable to within 0.2 °C. The temperature was measured throughout the scan time with a fluoro-optic probe, with an uncertainty of 0.16 °C. The probe was calibrated at the National Physical Laboratory (NPL) with traceability to the International Temperature Scale 1990 (ITS-90). MRS thermometry measures were based on single-voxel spectroscopy chemical shift differences between water and N-acetylaspartate (NAA), Δ(H20-NAA), using a Philips Achieva 3 T scanner. Six different phantom solutions with varying protein or ionic concentration, simulating potential tissue differences, were investigated within a temperature range of 21-42 °C. Results were compared with a similar study performed at 1.5 T to observe the effect of field strengths. Temperature calibration curves were plotted to convert Δ(H20-NAA) to apparent temperature. The apparent temperature changed by -0.2 °C/% of bovine serum albumin (BSA) and a trend of 0.5 °C/50 mM ionic concentration was observed. Differences in the calibration coefficients for the 10% BSA solution were seen in this study at 3 T compared with a study at 1.5 T. MRS thermometry may be utilized to measure temperature and the tissue microenvironment, which could provide unique unexplored information for brain abnormalities and other pathologies.

Snapshot Serengeti, high-frequency annotated camera trap images of 40 mammalian species in an African savanna

Camera traps can be used to address large-scale questions in community ecology by providing systematic data on an array of wide-ranging species. We deployed 225 camera traps across 1,125 km² in Serengeti National Park, Tanzania, to evaluate spatial and temporal inter-species dynamics. The cameras have operated continuously since 2010 and had accumulated 99,241 camera-trap days and produced 1.2 million sets of pictures by 2013. Members of the general public classified the images via the citizen-science website www.snapshotserengeti.org. Multiple users viewed each image and recorded the species, number of individuals, associated behaviours, and presence of young. Over 28,000 registered users contributed 10.8 million classifications. We applied a simple algorithm to aggregate these individual classifications into a final ‘consensus’ dataset, yielding a final classification for each image and a measure of agreement among individual answers. The consensus classifications and raw imagery provide an unparalleled opportunity to investigate multi-species dynamics in an intact ecosystem and a valuable resource for machine-learning and computer-vision research.

Spiral tissue phase velocity mapping in a breath-hold with non-cartesian SENSE

PURPOSE

Tissue phase velocity mapping (TPVM) is capable of reproducibly measuring regional myocardial velocities. However acquisition durations of navigator gated techniques are long and unpredictable while current breath-hold techniques have low temporal resolution. This study presents a spiral TPVM technique which acquires high resolution data within a clinically acceptable breath-hold duration.

METHODS

Ten healthy volunteers are scanned using a spiral sequence with temporal resolution of 24 ms and spatial resolution of 1.7 × 1.7 mm. Retrospective cardiac gating is used to acquire data over the entire cardiac cycle. The acquisition is accelerated by factors of 2 and 3 by use of non-Cartesian SENSE implemented on the Gadgetron GPU system resulting in breath-holds of 17 and 13 heartbeats, respectively. Systolic, early diastolic, and atrial systolic global and regional longitudinal, circumferential, and radial velocities are determined.

RESULTS

Global and regional velocities agree well with those previously reported. The two acceleration factors show no significant differences for any quantitative parameter and the results also closely match previously acquired higher spatial resolution navigator-gated data in the same subjects.

CONCLUSION

By using spiral trajectories and non-Cartesian SENSE high resolution, TPVM data can be acquired within a clinically acceptable breath-hold.

Patient perceptions of a comprehensive cancer navigation service

OBJECTIVE

Our aim was to determine the extent to which comprehensive navigation augments the provincial health system for meeting the needs of newly-diagnosed cancer patients (clients). We also assessed reactions of attending physicians to comprehensive navigation.

METHODS

Clients who completed navigation as an employee benefit or through membership in an insurance organization were polled to determine whether they needed help beyond that provided by the provincial health system and the extent to which that help was provided by navigation. Exit interviews were analyzed for perceptions of the clients about reactions by their attending physicians to navigation.

RESULTS

Of eligible clients, 72% responded. They reported needing help beyond that which the provincial system could provide in 64%-98% of specified areas. Navigation provided help in more than 90% of those cases. Almost all respondents (98%) appreciated having a designated oncology nurse navigator. Family doctors were perceived to be positive or neutral about navigation in 100% of exit interviews. Oncologists were positive or neutral in 92% (p < 0.001 for difference from family doctors).

CONCLUSIONS

In many areas, cancer patients need additional help beyond that which the provincial health system can provide. Comprehensive cancer navigation provides that help to a considerable extent. Clients perceived the reactions of attending physicians to comprehensive navigation to be generally supportive or neutral.

Classification of large acoustic datasets using machine learning and crowdsourcing: application to whale calls

Vocal communication is a primary communication method of killer and pilot whales, and is used for transmitting a broad range of messages and information for short and long distance. The large variation in call types of these species makes it challenging to categorize them. In this study, sounds recorded by audio sensors carried by ten killer whales and eight pilot whales close to the coasts of Norway, Iceland, and the Bahamas were analyzed using computer methods and citizen scientists as part of the Whale FM project. Results show that the computer analysis automatically separated the killer whales into Icelandic and Norwegian whales, and the pilot whales were separated into Norwegian long-finned and Bahamas short-finned pilot whales, showing that at least some whales from these two locations have different acoustic repertoires that can be sensed by the computer analysis. The citizen science analysis was also able to separate the whales to locations by their sounds, but the separation was somewhat less accurate compared to the computer method.

Mindfulness based interventions in multiple sclerosis--a systematic review

BACKGROUND

Multiple sclerosis (MS) is a stressful condition; depression, anxiety, pain and fatigue are all common problems. Mindfulness based interventions (MBIs) mitigate stress and prevent relapse in depression and are increasingly being used in healthcare. However, there are currently no systematic reviews of MBIs in people with MS. This review aims to evaluate the effectiveness of MBIs in people with MS.

METHODS

Systematic searches were carried out in seven major databases, using both subject headings and key words. Papers were screened, data extracted, quality appraised, and analysed by two reviewers independently, using predefined criteria. Study quality was assessed using the Cochrane Collaboration risk of bias tool. Perceived stress was the primary outcome. Secondary outcomes include mental health, physical health, quality of life, and health service utilisation. Statistical meta-analysis was not possible. Disagreements were adjudicated by a third party reviewer.

RESULTS

Three studies (n = 183 participants) were included in the final analysis. The studies were undertaken in Wales (n = 16, randomised controlled trial - (RCT)), Switzerland (n = 150, RCT), and the United States (n = 17, controlled trial). 146 (80%) participants were female; mean age (SD) was 48.6 (9.4) years. Relapsing remitting MS was the main diagnostic category (n = 123, 67%); 43 (26%) had secondary progressive disease; and the remainder were unspecified. MBIs lasted 6-8 weeks; attrition rates were variable (5-43%); all employed pre- post- measures; two had longer follow up; one at 3, and one at 6 months. Socio-economic status of participants was not made explicit; health service utilisation and costs were not reported. No study reported on perceived stress. All studies reported quality of life (QOL), mental health (anxiety and depression), physical (fatigue, standing balance, pain), and psychosocial measures. Statistically significant beneficial effects relating to QOL, mental health, and selected physical health measures were sustained at 3- and 6- month follow up.

CONCLUSION

From the limited data available, MBIs may benefit some MS patients in terms of QOL, mental health, and some physical health measures. Further studies are needed to clarify how MBIs might best serve the MS population.

Synthesis and characterization of mixed phase anatase TiO2 and sodium-doped TiO2(B) thin films by low pressure chemical vapour deposition (LPCVD)

Mixed phase anatase TiO₂ and TiO₂(B) thin films were synthesized using Low Pressure Chemical Vapour Deposition (LPCVD) onto glass substrates.

A pilot study of an enhanced mental health assessment during routine and discharge medicals in the British Armed Forces

OBJECTIVES

A pilot study to assess the practicality of introducing an enhanced mental health assessment (EMHA) into all routine and discharge medicals of the UK Armed Forces in order to facilitate treatment prior to and on return to civilian life.

METHODS

A pilot study was conducted using an EMHA questionnaire with questions about depression, anxiety, post-traumatic stress disorder, alcohol use, sleep and anger/irritability. At pilot sites, the EMHA was completed during all routine and discharge medicals between May 2011 and July 2011. At the end of the study period, qualitative data were collected from participating medical officers and practice managers regarding their opinions about the pilot study.

RESULTS

The quantitative data revealed an average pick-up rate for mental health (MH) problems. Out of the four military medical centres who participated and the 325 questionnaires collected, one referral to a Department of Community Mental Health was made. 26 (8%) patients were categorised as 'some concern and patient offered advice and/or reassurance'. The vast majority of patients were found to have no evidence of MH problems. However, using a validated alcohol screening tool, 64% of service personnel were found to have a score indicating 'higher risk drinking'. Analysis of the qualitative data suggests that the EMHA is an easy tool to implement with minimal additional time and resources needed. The interviewees pointed out a number of limitations and suggestions for possible further studies.

CONCLUSIONS

The pilot study successfully demonstrated that the EMHA questionnaire is easy to administer, does not take up a large amount of additional resources or manpower and provides a useful check of MH status. The study picked up an average number of MH cases and the questions on alcohol consumption highlighted that military personnel may be at a 'higher risk of drinking'.

The effects of pre-weaning undernutrition on the expression levels of free radical deactivating enzymes in the mouse brain

A mild degree of undernutrition brought about by restricting the amount of food in the diet is known to alter the life span of an animal. It has been hypothesised that this may be related to the effects of undernutrition on an animals anti-oxidant defense system. We have therefore, used real-time PCR (rt-PCR) techniques to determine the levels of mRNA expression for manganese superoxide dismutase (MnSOD), copper/zinc superoxide dismutase (Cu/ZnSOD), glutathione peroxidase 1 (GPx 1) and catalase in the brains of Quackenbush mice undernourished from conception until 21-post-natal days of age. It was found that 21- and 61-day-old undernourished mice had a deficit in the expression of Cu/ZnSOD in both the cerebellum and forebrain regions compared to age-matched controls. The expression of MnSOD was found to be greater in the cerebellum, but not the forebrain region, of 21-day-old undernourished mice. There were no significant differences in the expression of GPx 1 and catalase between control and undernourished or previously undernourished mice. Our results confirm that undernutrition during the early life of a mouse may disrupt some of the enzymes involved in the anti-oxidant defense systems.

Cold injuries in contemporary conflict

OBJECTIVES

To describe the cases of cold injury sustained during the most recent winter operational tour of Afghanistan, Op HERRICK 15.

METHODS

Retrospective review of all notified British military cases of cold injury sustained between 1 Oct 11 and 30 Mar 12 recorded by UK Medical Group Environmental Health Team.

RESULTS

14 patients with 13 Non-freezing Cold Injuries (NFCI) and two hypothermic injuries were identified. Five patients were of African ethnic decent. Eight out of 13 NFCI patients had probably suffered a previous injury, injuries were sustained from December until February and 9/13 NFCI patients had periods of static duties implicated in the injury mechanism. Eight patients were able to remain in operational theatre on restricted duties whilst 6/14 were evacuated home after sustaining their injuries.

CONCLUSIONS

Although awareness and equipment have improved, cold injuries remain an important cause of Disease and Non Battle Injury on current operations within the British Military. Cases of cold injury are probably under reported and often stem from situations where risk would seem predicable. It is hoped this article will assist in enabling greater understanding of contemporary operational cold injuries and continuing the development of preventative strategies.

To refer or not to refer: a qualitative study of reasons for referral from Role 1

OBJECTIVES

There are currently over 9000 British soldiers serving in Afghanistan. The Defence Medical Services provide primary health care to soldiers at forward locations using Regimental Medical Officers (RMOs) and General Duties Medical Officers (GDMOs). If required, GDMOs can refer patients to senior colleagues. Currently, little is known about the reasons for referrals by GDMOs. This study aims to identify the main factors affecting why GDMOs refer from forward locations.

METHODS

Nine GDMOs, who deployed on Operation HERRICK 13, were invited to join the study. They maintained a log of their referrals for two 14 day periods, one in each half of their tour. In addition, a semi-structured interview was performed with each GDMO in order to elicit the common themes surrounding referrals.

RESULTS

The mean referral rate was 0.9 referrals/GDMO/week. The main reasons for referral were dental problems, musculoskeletal injuries, abdominal pain of unknown cause, and ano-genital problems. Factors that influenced referrals included availability of forwardly projected services (dentist and physiotherapist), manpower availability at the locations, the availability of flights (affected by weather, enemy action, and schedule of routine flights), and the timing of the tour in relation to leave.

CONCLUSIONS

Referrals from GDMOs were due to doctor inexperience in the treatment of a particular condition, lack of access to investigations and the potential for deterioration in a location without adequate support. The referral decision process was affected by the patient's importance with regards to the mission, the weather and access to safe transportation. The introduction of clinical guidelines for common conditions in conjunction with minor alterations to GDMO training could help reduce referrals from Role 1, preserving manpower, reducing costs, and minimising risk to evacuation aircraft.