First case report of pre-mortem biopsy-proven kidney involvement by necrobiotic xanthogranuloma with monoclonal gammopathy.

Necrobiotic xanthogranuloma (NXG) is a rare non-Langerhans cell histiocytosis with characteristic cutaneous features and rare visceral involvement. More than 80% of individuals with this disease have a detectable paraprotein but the precise pathogenesis remains obscure. A 68-year-old man with known cutaneous necrobiotic xanthogranuloma presented with acute kidney injury and imaging suggestive of bilateral perinephric infiltration. Renal biopsy showed a prominent histiocytic infiltration of renal capsule and cortex with necrobiosis and characteristic 'Touton-type' giant cells suggestive of necrobiotic xanthogranuloma involvement. Kidney function returned to normal and cutaneous lesions improved with a combination of corticosteroid, chlorambucil and rituximab. This case represents only the second reported incidence of kidney involvement by necrobiotic xanthogranuloma and the first with acute kidney injury and pre-mortem histopathology. This report adds to a small body of literature on the diagnosis and management of visceral involvement by this rare disease.

Health concerns of cancer survivors after primary anti-cancer treatment.

PURPOSE: Cancer survivors experience significant health concerns compared to the general population. Sydney Survivorship Clinic (SSC) is a multi-disciplinary clinic aiming to help survivors treated with curative intent manage side effects, and establish a healthy lifestyle. Here, we determine the health concerns of survivors post-primary treatment. METHODS: Survivors completed questionnaires assessing symptoms, quality of life (QOL), distress, diet, and exercise before attending SSC, and a satisfaction survey after. Body mass index (BMI), clinical findings and recommendations were reviewed. Descriptive statistical methods were used. RESULTS: Overall, 410 new patients attended SSC between September 2013 and April 2018, with 385 survivors included in analysis: median age 57 years (range 18-86); 69% female; 43% breast, 31% colorectal and 19% haematological cancers. Median time from diagnosis, 12 months. Common symptoms of at least moderate severity: fatigue (45%), insomnia (37%), pain (34%), anxiety (31%) and with 56% having > 5 moderate-severe symptoms. Overall, 45% scored distress ≥ 4/10 and 62% were rated by clinical psychologist as having 'fear of cancer recurrence'. Compared to population mean of 50, mean global QOL T-score was 47.2, with physical and emotional well-being domains most affected. Average BMI was 28.2 kg/m2 (range 17.0-59.1); 61% overweight/obese. Only 31% met aerobic exercise guidelines. Overall, 98% 'agreed'/'completely agreed' attending the SSC was worthwhile, and 99% would recommend it to others. CONCLUSION: Distress, fear of cancer recurrence, fatigue, obesity and sedentary lifestyle are common in cancer survivors attending SSC and may best be addressed in a multi-disciplinary Survivorship Clinic to minimise longer-term effects. This model is well-rated by survivors.

Implementing peer review of teaching: a guide for dental educators.

Peer review of teaching (PRT) is well established and valued within higher education. Increasingly, dental educators involved in undergraduate or postgraduate teaching are required to undertake PRT as part of their teaching development. Despite this, there is a paucity of literature relating to PRT within dental education, and none that considers the implementation of PRT within large dental teaching establishments. This article describes in detail a staged process for the planning and implementation of PRT within a UK dental school. It uses relevant educational literature to supplement the authors' experiences and recommendations. By highlighting aspects of the process which are key to successful implementation, it is a useful guide for all dental educator teams who wish to successfully introduce, restructure or refresh a PRT scheme.

Peer review of teaching in UK dental schools. Is it happening? How successful is it?

Aim The aim of this study was to investigate the utilisation of peer review of teaching (PRT) within UK dental schools.Method A structured questionnaire was emailed to all sixteen UK dental schools seeking information on existing PRT schemes, level of staff engagement, and the success of schemes in relation to extent of operation and perceived benefit.Results A 100% response rate was achieved. Fourteen schools (88%) operate PRT schemes. For most, the expected frequency of staff engagement is annually, although there was a wide range between schools (minimum = once every five years, maximum = three times per year). Nine schools (64%) consider their schemes to be fully operational. Twelve schools (86%) feel their staff are either mostly or fully engaged. Reasons for sub-optimal operation and/or engagement include: newly introduced schemes, problems with compliance for off-campus staff, and loss of momentum. Thirteen schools (93%) consider that PRT benefits their teaching staff. Ten schools (71%) stated that changes are required to their schemes.Conclusion PRT is operating within the majority of U.K dental schools but the format and success of schemes varies. Schemes will benefit from ongoing development but changes should take into account evidence from the literature, particularly recognised models of PRT.

An anatomic study of local infiltration analgesia in total knee arthroplasty.

BACKGROUND: Local infiltration analgesia (LIA) is a relatively novel technique developed for effective pain control following total knee arthroplasty (TKA), reducing requirements for epidural or parenteral postoperative analgesia. This study investigated the anatomical spread of an LIA used in TKA to identify the nerve structures reached by the injected fluid. METHODS: Six fresh-frozen cadaveric lower limbs were injected according to a standardised LIA technique with a solution of latex and India ink to enable visualisation. Wounds were closed and limbs placed flat in a freezer at -20°C for two weeks. Limbs were then either sliced or dissected to identify solution locations. RESULTS: Solution was found from the proximal thigh to the middle of the lower leg. The main areas of concentration were the popliteal fossa, the anterior aspect of the femur and the subcutaneous tissue of the anterior aspect of the knee. There was less solution in the lower popliteal fossa. The solution was found to reach the majority of nerves, with good infiltration of nerves supplying the knee. CONCLUSIONS: These results support the positive clinical outcomes with this LIA technique. However, the lack of infiltration into the lower popliteal fossa suggests more fluid or a different injection point could be used. The solution reaching the extensor muscles of the lower leg is likely to have no beneficial analgesic effect for a TKA patient. The LIA technique is already used in clinical practice following total knee arthroplasty. Results from this study show there may be scope to optimise the injection sites in LIA technique.

A spatio-temporal detective quantum efficiency and its application to fluoroscopic systems.

PURPOSE: Fluoroscopic x-ray imaging systems are used extensively in spatio-temporal detection tasks and require a spatio-temporal description of system performance. No accepted metric exists that describes spatio-temporal fluoroscopic performance. The detective quantum efficiency (DQE) is a metric widely used in radiography to quantify system performance and as a surrogate measure of patient "dose efficiency". It has been applied previously to fluoroscopic systems with the introduction of a temporal correction factor. However, the use of a temporally-corrected DQE does not provide system temporal information and it is only valid under specific conditions, many of which are not likely to be satisfied by suboptimal systems. The authors propose a spatio-temporal DQE that describes performance in both space and time and is applicable to all spatio-temporal quantum-based imaging systems. METHODS: The authors define a spatio-temporal DQE (two spatial-frequency axes and one temporal-frequency axis) in terms of a small-signal spatio-temporal modulation transfer function (MTF) and spatio-temporal noise power spectrum (NPS). Measurements were made on an x-ray image intensifier-based bench-top system using continuous fluoroscopy with an RQA-5 beam at 3.9 microR/frame and hardened 50 kVp beam (0.8 mm Cu filtration added) at 1.9 microR/frame. RESULTS: A zero-frequency DQE value of 0.64 was measured under both conditions. Nonideal performance was noted at both larger spatial and temporal frequencies; DQE values decreased by approximately 50% at the cutoff temporal frequency of 15 Hz. CONCLUSIONS: The spatio-temporal DQE enables measurements of decreased temporal system performance at larger temporal frequencies analogous to previous measurements of decreased (spatial) performance. This marks the first time that system performance and dose efficiency in both space and time have been measured on a fluoroscopic system using DQE and is the first step toward the generalized use of DQE on clinical fluoroscopic systems.

General practitioners' views and experiences of over-the-counter simvastatin in Scotland.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Statins are widely used for the primary and secondary prevention of coronary events in high risk populations. In 2004 simvastatin was reclassified in the UK from prescription only to being available over-the-counter (OTC). WHAT THIS STUDY ADDS: The majority of GPs do not support the supply of OTC simvastatin by the community pharmacist. GPs were particularly concerned by the lack of cholesterol and blood pressure data in the CHD risk assessment prior to sale. AIMS: The aims of this study were to determine the views and experiences of Scottish GPs towards CVD risk assessment by community pharmacists and the supply and sale of simvastatin. METHODS: A cross sectional postal questionnaire survey of all primary care general practices in Scotland was carried out. The main outcome measure was GPs' awareness of and opinions regarding OTC simvastatin use, experience of OTC simvastatin and opinions regarding community pharmacist involvement in CHD risk assessment. RESULTS: A response rate of 45.7% was obtained. The majority (92.6%, 428) were aware that community pharmacists could sell simvastatin to reduce the risk of a first coronary event in individuals at moderate risk of CHD. However, over half (55.6%, 257) believed that the OTC sale of simvastatin was inappropriate. Just over half were unaware that the pharmacist's CHD risk assessment for the sale of simvastatin did not include lipid (54.8%, n=253) or blood pressure measurement (53.7%, n=248) and 56.7% (262) and 57.8% (267) of respondents, respectively, thought these omissions inappropriate. Almost half of the respondents (48.1%, 222) supported community pharmacists supplying simvastatin as supplementary prescribers while fewer (26.6%, 132) were in favour of supply via an independent prescribing arrangement. CONCLUSION: This study confirms that the majority of GPs do not support the supply of OTC simvastatin by the community pharmacist, being particularly concerned by the lack of cholesterol and blood pressure data in the CHD risk assessment prior to sale. Other methods of pharmacy based simvastatin supply including supplementary prescribing merit further evaluation.

Cross-sectional survey of community pharmacists' views of the electronic Minor Ailment Service in Scotland.

OBJECTIVES: The aim was to investigate community pharmacists' views on the implementation of the electronic Minor Ailment Service (e-MAS) in Scottish community pharmacies and to quantify the barriers and facilitators to service provision. METHODS: A postal cross-sectional survey of all community pharmacies in Scotland (n = 1138) was conducted. A combination of open, closed and Likert-type questions were used. KEY FINDINGS: A response rate of 49.5% was achieved. A majority of respondents (over 84%) ranked their level of implementation of e-MAS as 4 or 5 on the five-point scale where point 1 represented 'not at all' and 5 represented 'very high'. A majority also identified opportunities to extend professional roles (83.3%), opportunities for more effective patient treatment (78.5%), opportunities to better meet patient expectations (74.4%) and financial advantage to their pharmacy (52.6%) as benefits of e-MAS. Suspected misuse/overuse of the service by some customers (75.1%) and time required for recording each consultation or supply (61.3%) were two barriers agreed upon by the majority of the respondents. CONCLUSIONS: A majority of respondents had positive views towards e-MAS. The benefits agreed upon by the majority of the respondents relate to known facilitators of community pharmacy practice change. Major barriers, namely suspected misuse of the service by some customers and timely process for recording consultation or supply, could affect pharmacists' efficiency in service delivery and need to be addressed. These results could inform similar schemes that may be introduced locally in the UK or elsewhere.

A small-signal approach to temporal modulation transfer functions with exposure-rate dependence and its application to fluoroscopic detective quantum efficiency.

The detective quantum efficiency (DQE) is a metric widely used in radiography to quantify system performance and as a surrogate measure of patient "dose efficiency." It has been applied previously to fluoroscopic systems with the introduction of a temporal correction factor. Calculation of this correction factor relies on measurements of the temporal modulation transfer function (MTF). However, the temporal MTF is often exposure-rate dependent, violating a necessary Fourier linearity requirement. The authors show that a Fourier analysis is appropriate for fluoroscopic systems if a "small-signal" approach is used. Using a semitransparent edge, a lag-corrected DQE is described and measured for an x-ray image intensifier-based fluoroscopic system under continuous (non-pulsed) exposure conditions. It was found that results were equivalent for both rising and falling-edge profiles independent of edge attenuation when effective attenuation was in the range of 0.1-0.6. This suggests that this range is appropriate for measuring the small-signal temporal MTF. In general, lag was greatest at low exposure rates. It was also found that results obtained using a falling-edge profile with a radiopaque edge were equivalent to the small-signal results for the test system. If this result is found to be true generally, it removes the need for the small-signal approach. Lag-corrected DQE values were validated by comparison with radiographic DQE values obtained using very long exposures under the same conditions. Lag was observed to inflate DQE measurements by up to 50% when ignored.

Pseudomonoenergetic x-ray diffraction measurements using balanced filters for coherent-scatter computed tomography.

Coherent-scatter computed tomography (CSCT) is a method of "composition" imaging based on measurements of diffraction patterns from tissues. Use of an x-ray tube degrades scatter pattern angular resolution due to the x-ray spectral width, making it difficult to uniquely identify some materials. The use of two transmission filters with similar atomic numbers (balanced "Ross filters") to generate pseudomonoenergetic scatter patterns is described as it applies to CSCT. An analysis of angular-blur mechanisms reveals that focal spot size and beam width are the most important factors determining Bragg-peak width when Er-Tm filters are used. A relative RMS spectral width of 1% can be achieved in the difference spectrum and a Bragg-peak RMS angular width of approximately 0.14 degree (relative width of 3% at 5 degrees scatter angle) can be achieved with an effective energy of 58 keV.

Normalization of the modulation transfer function: the open-field approach.

The modulation transfer function (MTF) is widely used to describe the spatial resolution of x-ray imaging systems. The MTF is defined to have a zero-frequency value of unity, and it is common practice to ensure this by normalizing a measured MTF curve by the zero-frequency value. However, truncation of the line spread function (LSF) within a finite region of interest (ROI) results in spectral leakage and causes a reduction in the measured MTF zero-frequency value equal to the area of truncated LSF tails. Subsequent normalization by this value may result in inflated MTF values. We show that open-field normalization with the edge method produces accurate MTF values at all nonzero frequencies without need for further normalization by the zero-frequency value, regardless of ROI size. While both normalization techniques are equivalent for a sufficiently large ROI, a 5% inflation in MTF values was observed for a CsI-based flat-panel system when using a 10 cm ROI. Use of open-field normalization avoids potential inflation caused by zero-frequency normalization.

Exploring patients' perspectives of pharmacist supplementary prescribing in Scotland.

AIM: The aim of this study was to explore patients' perspectives and experiences of pharmacist supplementary prescribing (SP) in Scotland. METHOD: A survey in primary and secondary care in Scotland. Pharmacist supplementary prescribers (n = 10) were purposively selected across Scotland. All pharmacists distributed questionnaires to 20 consecutive patients as they attended appointments during October to December 2006. Reminders were mailed to all 20 patients by each pharmacist 2 weeks after initial distribution. MAIN OUTCOME MEASURES: The questionnaire contained items on: attitudes towards pharmacist SP derived from earlier qualitative research; consultation satisfaction derived from a validated scale developed initially for general practitioners, with the term 'doctor' being replaced by 'pharmacist prescriber'; and demographics. Closed and Likert scales were used as response options. RESULTS: One pharmacist withdrew. The patient response rate was 57.2% (103/180). The median age was 67 years (interquartile range 56.5-73 years), with 53.4% being female. Most (76, 73.8%) consulted with the pharmacist in a general practice setting. Patients reported positive consultation experiences with 89.3% agreeing/strongly agreeing that they were satisfied with the consultation, 78.7% thought the pharmacist told them everything about their treatment and 72.9% felt the pharmacist was interested in them as a person. Most patients were positive in their attitudes, agreeing that they would recommend a pharmacist prescriber to others and that they had trust in the pharmacist. However, 65% would prefer to consult a doctor. CONCLUSION: Most patient respondents were satisfied with, and had a positive attitude towards, pharmacist prescribing consultations. However, most patients would still elect to see a doctor given the choice.

Fundamental x-ray interaction limits in diagnostic imaging detectors: spatial resolution.

The practice of diagnostic x-ray imaging has been transformed with the emergence of digital detector technology. Although digital systems offer many practical advantages over conventional film-based systems, their spatial resolution performance can be a limitation. The authors present a Monte Carlo study to determine fundamental resolution limits caused by x-ray interactions in four converter materials: Amorphous silicon (a-Si), amorphous selenium, cesium iodide, and lead iodide. The "x-ray interaction" modulation transfer function (MTF) was determined for each material and compared in terms of the 50% MTF spatial frequency and Wagner's effective aperture for incident photon energies between 10 and 150 keV and various converter thicknesses. Several conclusions can be drawn from their Monte Carlo study. (i) In low-Z (a-Si) converters, reabsorption of Compton scatter x rays limits spatial resolution with a sharp MTF drop at very low spatial frequencies (< 0.3 cycles/mm), especially above 60 keV; while in high-Z materials, reabsorption of characteristic x rays plays a dominant role, resulting in a mid-frequency (1-5 cycles/mm) MTF drop. (ii) Coherent scatter plays a minor role in the x-ray interaction MTF. (iii) The spread of energy due to secondary electron (e.g., photoelectrons) transport is significant only at very high spatial frequencies. (iv) Unlike the spread of optical light in phosphors, the spread of absorbed energy from x-ray interactions does not significantly degrade spatial resolution as converter thickness is increased. (v) The effective aperture results reported here represent fundamental spatial resolution limits of the materials tested and serve as target benchmarks for the design and development of future digital x-ray detectors.

Fundamental x-ray interaction limits in diagnostic imaging detectors: frequency-dependent Swank noise.

A frequency-dependent x-ray Swank factor based on the "x-ray interaction" modulation transfer function and normalized noise power spectrum is determined from a Monte Carlo analysis. This factor was calculated in four converter materials: amorphous silicon (a-Si), amorphous selenium (a-Se), cesium iodide (CsI), and lead iodide (PbI2) for incident photon energies between 10 and 150 keV and various converter thicknesses. When scaled by the quantum efficiency, the x-ray Swank factor describes the best possible detective quantum efficiency (DQE) a detector can have. As such, this x-ray interaction DQE provides a target performance benchmark. It is expressed as a function of (Fourier-based) spatial frequency and takes into consideration signal and noise correlations introduced by reabsorption of Compton scatter and photoelectric characteristic emissions. It is shown that the x-ray Swank factor is largely insensitive to converter thickness for quantum efficiency values greater than 0.5. Thus, while most of the tabulated values correspond to thick converters with a quantum efficiency of 0.99, they are appropriate to use for many detectors in current use. A simple expression for the x-ray interaction DQE of digital detectors (including noise aliasing) is derived in terms of the quantum efficiency, x-ray Swank factor, detector element size, and fill factor. Good agreement is shown with DQE curves published by other investigators for each converter material, and the conditions required to achieve this ideal performance are discussed. For high-resolution imaging applications, the x-ray Swank factor indicates: (i) a-Si should only be used at low-energy (e.g., mammography); (ii) a-Se has the most promise for any application below 100 keV; and (iii) while quantum efficiency may be increased at energies just above the K edge in CsI and PbI2, this benefit is offset by a substantial drop in the x-ray Swank factor, particularly at high spatial frequencies.

A moving slanted-edge method to measure the temporal modulation transfer function of fluoroscopic systems.

Lag in fluoroscopic systems introduces a frame-averaging effect that reduces measurements of image noise and incorrectly inflates measurements of the detective quantum efficiency (DQE). A correction can be implemented based on measurements of the temporal modulation transfer function (MTF). We introduce a method of measuring the temporal MTF under fluoroscopic conditions using a moving slanted edge, a generalization of the slanted-edge method used to measure the (spatial) MTF, providing the temporal MTF of the entire imaging system. The method uses a single x-ray exposure, constant edge velocity, and assumes spatial and temporal blurring are separable. The method was validated on a laboratory x-ray image intensifier (XRII) system by comparison with direct measurements of the XRII optical response, showing excellent agreement over the entire frequency range tested (+/- 100 Hz). With proper access to linearized data and continuous fluoroscopy, this method can be implemented in a clinical setting on both XRII and flat-panel detectors. It is shown that the temporal MTF of the CsI-based validation system is a function of exposure rate. The rising-edge response showed more lag than the falling edge, and the temporal MTF decreased with decreasing exposure rate. It is suggested that a small-signal approach, in which the range of exposure rates is restricted to a linear range by using a semitransparent moving edge, would be appropriate for measuring the DQE of these systems.

Subacute cardiac toxicity following autologous haematopoietic stem cell transplantation in patients with normal cardiac function.

OBJECTIVE: To investigate subacute cardiac toxicity in patients with normal baseline cardiac function following autologous haematopoietic stem cell transplantation. DESIGN: Prospective observational study. PATIENT AND METHODS: Thirty-two consecutive patients (mean (SD) age 60 (11) years) with normal left ventricular ejection fraction (LVEF >or=50%) undergoing autologous haematopoietic stem cell transplantation were studied. Transthoracic echocardiography (including colour tissue Doppler imaging-derived myocardial velocities, strain and strain rates), troponin-T and B-type natriuretic peptide (BNP) and clinical details were recorded at baseline, after conditioning chemotherapy and serially over 6 weeks from the day of transplantation. RESULTS: The mean (SD) LVEF at baseline was 62 (6)% and decreased to 55 (16)%, 6 weeks after transplantation (p = 0.007). Cardiac toxicity (>or=10% absolute decline of LVEF to an LVEF

Sci-Sat AM(1): Imaging-07: Open field normalization: How to avoid inflation to MTF and DQE values caused by zero-frequency normalization.

PURPOSE: To show that the novel open-field normalization technique prevents a common error in calculation of the detective quantum efficiency (DQE) caused by zero-frequency normalization of the modulation transfer function (MTF). METHOD AND MATERIALS: Models describing zero-frequency and open-field normalization were used to derive the resulting measured MTF, noise power spectrum (NPS) and DQE using a finite region of interest (ROI) of image data. Simulated one-dimensional images containing Gaussian blur were used to model a deterministic system and to calculate the resultant values. Measurements were made using both zero-frequency and open-field normalization with ROIs ranging in size from 1-10 cm. RESULTS: Use of a finite ROI results in truncation of the system line-spread function (LSF) causing the zero-frequency value of the measured MTF to be less than the true MTF value of unity, and causes spectral leakage in both the MTF and NPS. Zero-frequency normalization of the MTF inflates values at all non-zero frequencies. Since no zero-frequency normalization is performed on the NPS, this causes inflated DQE values. Simulated results show a 6% inflation of DQE values for a ROI of 10 cm, which increases as the ROI is reduced. Open-field normalization accurately determines MTF and NPS (and thus DQE) values at all frequencies away from zero frequency. CONCLUSION: Open-field normalization measurements provide a good estimate of the true MTF and DQE. This approach should be used to avoid a common error in DQE calculations that is not obvious and inflates DQE calculations by 5-20%.

Views of pharmacists and mentors on experiential learning for pharmacist supplementary prescribing trainees.

OBJECTIVE: To explore the views and experiences of pharmacists and their mentoring designated medical practitioners (DMPs) about the 'period of learning in practice' (PLP) as part of supplementary prescribing (SP) training. METHOD: Two focus groups (n = 5 and 7) of SP pharmacists were organised in Scotland. The experiences and views of DMPs (n = 13) were explored using one-to-one telephone interviews. The focus groups and interviews were transcribed verbatim and analysed using the framework approach. MAIN OUTCOME MEASURES: Views and experiences of pharmacists and DMPs about the PLP. RESULTS: Planning the PLP in consultation with the DMP was found to be crucial for an optimal learning experience. Pharmacists who did not have a close working relationship with the medical team had difficulties in identifying a DMP and organising their PLP. Participants stressed the importance of focusing on and achieving the core competencies for prescribers during the PLP. Input from doctors involved in the training of others, review of consultation videos, and formal independent assessment including clinical assessment at the end of the PLP might improve the quality of the PLP. Forums for discussing experiences during the PLP and gathering information might be valuable. CONCLUSION: Our findings have implications for prescribing training for pharmacists in the future. The PLP should focus on core competencies with input from doctors involved in the training of others and have a formal assessment of consultation skills. Support for pharmacists in organising the PLP and forums for discussing experiences during the PLP would be valuable.

Experiential learning as part of pharmacist supplementary prescribing training: feedback from trainees and their mentors.

BACKGROUND: A period of learning in practice (PLP) is an integral part of supplementary prescribing training for pharmacists in Great Britain. During the PLP, a designated medical practitioner (DMP) supervises and supports the trainee to develop competence in prescribing. OBJECTIVE: To evaluate the views and experiences of supplementary prescribing pharmacists and DMPs regarding the PLP and identify their perceived support needs during the PLP. METHODS: Prepiloted questionnaires were mailed in September 2006 to all pharmacists who had started their supplementary prescribing training at The Robert Gordon University, Aberdeen, Scotland (n = 242) and their DMPs (n = 232). Nonrespondents were sent up to 2 reminders. Responses were analyzed using descriptive and comparative statistics; responses to open questions were analyzed thematically. RESULTS: Responses were received from 186 (76.9%) pharmacists and 144 (62.1%) DMPs. Just over half of the pharmacists agreed/strongly agreed that they knew what was expected of them and their DMPs during the PLP, but less than half agreed/strongly agreed that it was important to communicate with pharmacist colleagues in the prescribing course. One hundred twelve (60.2%) pharmacists had their consultation skills reviewed by their DMPs during the PLP. Opportunities for professional development and teamwork were regarded as major positive experiences by both pharmacists and DMPs. Organizational, attitudinal, and time barriers were also reported. There was considerable interest among both pharmacists and DMPs for an Internet-based support network during the PLP. CONCLUSIONS: Information on the roles and responsibilities of pharmacists and DMPs during the PLP should be enhanced. The Internet could be a useful medium for communication during the PLP. Input from a multidisciplinary team of healthcare professionals and review of consultation videos could further enhance the PLP experience.

Signal and noise transfer properties of photoelectric interactions in diagnostic x-ray imaging detectors.

Image quality in diagnostic x-ray imaging is ultimately limited by the statistical properties governing how, and where, x-ray energy is deposited in a detector. This in turn depends on the physics of the underlying x-ray interactions. In the diagnostic energy range (10-100 keV), most of the energy deposited in a detector is through photoelectric interactions. We present a theoretical model of the photoelectric effect that specifically addresses the statistical nature of energy absorption by photoelectrons, K and L characteristic x rays, and Auger electrons. A cascaded-systems approach is used that employs a complex structure of parallel cascades to describe signal and noise transfer through the photoelectric effect in terms of the modulation transfer function, Wiener noise power spectrum, and detective quantum efficiency (DQE). The model was evaluated by comparing results with Monte Carlo calculations for x-ray converters based on amorphous selenium (a-Se) and lead (Pb), representing both low and high-Z materials. When electron transport considerations can be neglected, excellent agreement (within 3%) is obtained for each metric over the entire diagnostic energy range in both a-Se and Pb detectors up to 30 cycles/mm, the highest frequency tested. The cascaded model overstates the DQE when the electron range cannot be ignored. This occurs at approximately two cycles/mm in a-Se at an incident photon energy of 80 keV, whereas in Pb, excellent agreement is obtained for the DQE over the entire diagnostic energy range. However, within the context of mammography (20 keV) and micro-computed tomography (40 keV), the effects of electron transport on the DQE are negligible compared to fluorescence reabsorption, which can lead to decreases of up to 30% and 20% in a-Se and Pb, respectively, at 20 keV; and 10% and 5%, respectively, at 40 keV. It is shown that when Swank noise is identified in a Fourier model, the Swank factor must be frequency dependent. This factor decreases quickly with frequency, and in the case of a-Se and Pb, decreases by up to a factor of 3 at five cycles/mm immediately above the K edge. The frequency-dependent Swank factor is also equivalent to what we call the "photoelectric DQE," which describes signal and noise transfer through photoelectric interactions.