Sub-calcaneal plantar fat pad assessment using dual-energy computed tomography: First experience in the diabetic foot.

BACKGROUND: This study assessed the use of dual-energy computed tomography (CT) to evaluate sub-calcaneal plantar fat pad changes in people with diabetic neuropathy. METHODS: Dual-energy CT scans of people with diabetic neuropathy and non-diabetic controls were retrospectively included. Average CT values (in Hounsfield Units) and thickness (in centimeters) of the sub-calcaneal plantar fat pad were measured in mono-energetic images at two energy levels (40 keV and 70 keV). The CT values measured in patients with diabetic neuropathy were correlated to barefoot plantar pressure measurements performed during walking in a clinical setting. FINDINGS: Forty-five dual-energy CT scans of people with diabetic neuropathy and eleven DECT scans of non-diabetic controls were included. Mean sub-calcaneal plantar fat pad thickness did not significantly differ between groups (diabetes group 1.20 ± 0.34 cm vs. control group 1.21 ± 0.28 cm, P = 0.585). CT values at both 40 keV (-34.7 ± 48.7 HU vs. -76.0 ± 42.8 HU, P = 0.013) and 70 keV (-11.2 ± 30.8 HU vs. -36.3 ± 27.2 HU, P = 0.017) were significantly higher in the diabetes group compared to controls, thus contained less fatty tissue. This elevation was most apparent in patients with Type 1 diabetes. CT values positively correlated with the mean peak plantar pressure. INTERPRETATION: Dual-energy CT was able to detect changes in the plantar fat pad of people with diabetic neuropathy.

Assessment of foot deformities in individuals with cerebral palsy using weight-bearing CT.

OBJECTIVE: The aims of this study were to visualize and quantify relative bone positions in the feet of individuals with cerebral palsy (CP) with a foot deformity and compare bone positions with those of typically developed (TD) controls. MATERIALS AND METHODS: Weight-bearing CT images of 14 individuals with CP scheduled for tendon transfer and/or bony surgery and of 20 TD controls were acquired on a Planmed Verity WBCT scanner. Centroids of the navicular and calcaneus with respect to the talus were used to quantify foot deformities. All taluses were aligned and the size and dimensions of the individuals' talus were scaled to correct for differences in bone sizes. In order to visualize and quantify variations in relative bone positions, 95% CI ellipsoids and standard deviations in its principle X-, Y-, and Z-directions were determined. RESULTS: In individuals with CP (age 11-17), a large variation in centroid positions was observed compared to data of TD controls. Radiuses of the ellipsoids, representing the standard deviations of the 95% CI in the principle X-, Y-, and Z-directions, were larger in individuals with CP compared to TD controls for both the calcaneus (3.16 vs 1.86 mm, 4.26 vs 2.60 mm, 9.19 vs 3.60 mm) and navicular (4.63 vs 1.55 mm, 5.18 vs 2.10 mm, 16.07 vs 4.16 mm). CONCLUSION: By determining centroids of the calcaneus and navicular with respect to the talus on WBCT images, normal and abnormal relative bone positions can be visualized and quantified in individuals with CP with various foot deformities.

Interdisciplinary consensus of virtual monochromatic dual-energy CT images: is there discrepancy in preferred photon energy between surgeons and radiologists for the assessment of non-unions?

AIM: To investigate possible differences between surgeons and radiologists in selecting optimal photon energy settings from a set of virtual monochromatic dual-energy computed tomography (CT) images for the assessment of bone union in patients with a suspected non-union of the appendicular skeleton. MATERIALS AND METHODS: Fifty patients suspected of having bone non-union after operative fracture treatment with a variety of fixation implants were included. Patients were scanned on a dual-source CT machine using 150/100-kVp. Monochromatic images were extracted at 70, 90, 110, 130, 150, and 190 keV. Images were reviewed by 159 orthopaedic trauma surgeons and 12 musculoskeletal radiologists in order to select the best and worst energy setting to assess bone union. Furthermore, a confidence score (1-4) was given in selecting the best and worst setting to assess bone union. RESULTS: Monochromatic 190 keV images were selected most frequently as the optimal energy in titanium (34.8%), stainless steel (40%), and combined implants of stainless steel and titanium (40.5%). Confidence scores and average optimal energies were higher and average worst energies were lower for radiologists compared to surgeons in all hardware (p<0.05). Differences in optimal energy were not statistically significant for different alloys or type of fixation implant in both groups. CONCLUSIONS: In both observer groups, 190 keV images were selected most frequently as the optimal energy to assess bone union in patients with a suspected non-union of the appendicular skeleton with hardware in situ. On average, musculoskeletal radiologists selected higher optimal and lower worst energy settings and were more confident in selecting both energy settings than orthopaedic trauma surgeons.

It's a thin line: development and validation of Dixon MRI-based semi-quantitative assessment of stress-related bone marrow edema in the wrists of young gymnasts and non-gymnasts.

PURPOSE: To assess reliability and clinical utility of evaluating stress-related metaphyseal water distribution using a semi-quantitative Dixon MRI-based method for early diagnosis of physeal stress injuries in adolescent gymnasts. METHODS: Twenty-four gymnasts with clinically suspected overuse injury of the distal radial physis, 18 asymptomatic gymnasts, and 24 non-gymnast controls aged 12 ± 1.5 years prospectively underwent hand radiographs and 3T MRI of the wrist including coronal T1-weighted and T2-weighted Dixon sequences. Two raters measured metaphyseal water signal fraction in 13 radial and ulnar regions of interest (ROI). Inter- and intrarater reliability, interslice (between 3 middle radial slices), and inter-ROI (between 3 ROIs on same level) reliability were assessed using intraclass correlation coefficients (ICC). Water signal fractions and their within-person ratios in distal versus most proximal ROIs were compared between groups using one-way analysis of variance. RESULTS: Inter- and intrarater ICCs were 0.79-0.99 and 0.94-1.0 for T1-weighted, and 0.88-1.0 and 0.88-1.0 for T2-weighted Dixon. Interslice and inter-ROI ICCs were 0.55-0.94 and 0.95-0.97 for T1-weighted, and 0.70-0.96 and 0.96-0.97 for T2-weighted Dixon. Metaphyseal water signal fraction in symptomatic gymnasts was higher in six distal ROIs compared with asymptomatic gymnasts and in nine ROIs compared with non-gymnasts (p < 0.05). Metaphyseal water score (ratio of distal versus most proximal ROIs) was 1.61 in symptomatic gymnasts and 1.35 in asymptomatic gymnasts on T2-weighted Dixon (p < 0.05). CONCLUSION: Semi-quantitative Dixon MRI-based water signal fraction assessment has good to excellent reproducibility and shows increased metaphyseal water scores in symptomatic gymnasts compared with asymptomatic gymnastic peers. KEY POINTS: • The proposed Dixon MRI-based semi-quantitative method for assessment of metaphyseal bone marrow water content is reliable, with off-the-shelf availability and short scan times. • The metaphyseal water score allows comparisons between gymnasts using a within-person reference area for unaffected metaphyseal bone. • As metaphyseal water score was increased in symptomatic gymnasts compared with asymptomatic gymnasts, this semi-quantitative method can potentially be used as an indicator of bone marrow edema in the early diagnosis of gymnastic physeal stress injury.

Carpal Alignment: A New Method for Assessment.

Background Carpal alignment may be used as a tool to evaluate fracture reduction in patients with distal radius fractures. However, there is little consensus on how to measure and quantify carpal alignment. Purpose The aim of this study was to compare the inter- and intraobserver variability of a new perpendicular method with the existing method in fractured and unfractured wrists. Additionally, the normal distribution of carpal alignment in unfractured wrists was investigated. Patients and Methods Carpal alignment was assessed on lateral plain radiographs using two different methods, one described by Ng and McQueen and another newly proposed method, the perpendicular method. Using the perpendicular method, the observer draws one line along the inner rim of the volar cortex of the radius and one perpendicular line to the center of the capitate. The carpus is aligned when the line along the inner rim transects the center of the capitate. Three examiners measured the carpal alignment in 50 patients with nonfractured and 50 patients with fractured distal radius. Intra- and interobserver variability for both methods were determined. Results The interobserver coefficient for the perpendicular method was 0.98 and that for the Ng method was 0.86. The intraobserver coefficients for three examiners were 0.89, 0.62, and 0.63, respectively, for the Ng method. For the perpendicular method, the intraobserver variability was 0.96, 0.89, and 0.72, respectively. In patients with unfractured wrists, the mean perpendicular to the center of the capitate was 0.25 mm dorsally. Conclusion The new proposed method is a reproducible method for measuring carpal alignment with a high inter- and intraclass coefficient. Clinical Relevance This method of measurement allows for a reproducible technique for measuring carpal alignment.

Diagnostic performance of MRI for assessment of response to neoadjuvant chemoradiotherapy in oesophageal cancer.

BACKGROUND: Patients with a pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for oesophageal cancer may benefit from non-surgical management. The aim of this study was to determine the diagnostic performance of visual response assessment of the primary tumour after nCRT on T2-weighted (T2W) and diffusion-weighted (DW) MRI. METHODS: Patients with locally advanced oesophageal cancer who underwent T2W- and DW-MRI (1·5 T) before and after nCRT in two hospitals, between July 2013 and September 2017, were included in this prospective study. Three radiologists evaluated T2W images retrospectively using a five-point score for the assessment of residual tumour in a blinded manner and immediately rescored after adding DW-MRI. Histopathology of the resection specimen was used as the reference standard; ypT0 represented a pCR. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve (AUC) and interobserver agreement were calculated. RESULTS: Twelve of 51 patients (24 per cent) had a pCR. The sensitivity and specificity of T2W-MRI for detection of residual tumour ranged from 90 to 100 and 8 to 25 per cent respectively. Respective values for T2W + DW-MRI were 90-97 and 42-50 per cent. AUCs for the three readers were 0·65, 0·66 and 0·68 on T2W-MRI, and 0·71, 0·70 and 0·70 on T2W + DW-MRI (P = 0·441, P = 0·611 and P = 0·828 for readers 1, 2 and 3 respectively). The κ value for interobserver agreement improved from 0·24-0·55 on T2W-MRI to 0·55-0·71 with DW-MRI. CONCLUSION: Preoperative assessment of residual tumour on MRI after nCRT for oesophageal cancer is feasible with high sensitivity, reflecting a low chance of missing residual tumour. However, the specificity was low; this results in overstaging of complete responders as having residual tumour and, consequently, overtreatment.

Risk of chronic ankle instability: A reliability study on radiographic assessment of the ankle joint geometry.

BACKGROUND: Chronic ankle instability (CAI) is a multifactorial disabling condition. Ideally all factors contributing to CAI are identified and implemented in a risk assessment model. However, they need to meet strict reliability requirements. To assess usability of radiographic factors for this risk assessment model and future clinical practice, the objective of the current study was to assess the intra and inter observer reliability of three radiographic measurements. METHODS AND METHODS: The radiographs of 39 consecutive patients, at least 16years, who visited the Emergency Department after sustaining a lateral ankle sprain (LAS), were assessed by four observers. The radiographic measurements included absolute and relative ankle alignment, sagittal fibular position and ankle joint congruency (talar radius and height, and tibiotalar sector), performed twice by all observers independently. Reliability was assessed by calculating the Intraclass Correlation Coefficient (ICC) which was considered good when ICC>0.70. RESULTS: The intra observer reliability of the absolute and relative fibular position, and talar height were good to excellent, (ICC 0.84-0.98, 0.85-0.98, and 0.79-0.93, respectively). The talar radius (ICC 0.69-0.89) was moderate to good. The overall inter observer reliability was good for the absolute and relative fibular position, and talar radius (ICC 0.84, 0.86, and 0.79, respectively). Other measurements had ICC values of <0.70. CONCLUSIONS: In an effort to identify the multifactorial nature of CAI, both the fibular position and the talar radius measurements showed good observer reliability, and will be implemented in a future risk assessment models. The other measurements are too prone for measurement errors, for future reference. LEVEL OF EVIDENCE: IV Case Series.

Tears of the supraspinatus tendon: assessment with indirect magnetic resonance arthrography in 67 patients with arthroscopic correlation.

BACKGROUND: Magnetic resonance (MR) arthrography is generally regarded as the gold standard for shoulder imaging. As an alternative to direct MR arthrography, the less invasive indirect MR arthrography technique was proposed, offering logistic advantages because fluoroscopic or ultrasonographic guidance for joint injection is not required. PURPOSE: To assess the diagnostic performance of indirect MR arthrography in the diagnosis of full- and partial-thickness supraspinatus tears in a symptomatic population. MATERIAL AND METHODS: Two radiologists with different levels of experience independently and retrospectively interpreted indirect MR (1.5T) arthrograms of the shoulder obtained in 67 symptomatic patients who underwent subsequent arthroscopy. On MR, the supraspinatus tendon was evaluated for full- or partial-thickness tear. With arthroscopy as the standard of reference, sensitivity, specificity, and diagnostic accuracy of indirect MR arthrography in the detection of full- and partial-thickness tears of the supraspinatus tendon was calculated. Kappa (kappa) statistics were used for the assessment of the agreement between arthroscopic and imaging findings and for the assessment of interobserver agreement. RESULTS: For full-thickness tears of the supraspinatus tendon, sensitivities, specificities, and accuracies exceeded 90% for both observers, with excellent interobserver agreement (kappa = 0.910). For partial-thickness tears, sensitivities (38-50%) and accuracies (76-78%) were poor for both reviewers, and interobserver agreement was moderate (kappa = 0.491). Discrepancies between MR diagnosis and arthroscopy were predominantly observed with small partial-thickness tears. CONCLUSION: Indirect MR arthrography is highly accurate in the diagnosis of full-thickness rotator cuff tears. However, the diagnosis of partial-thickness tears with indirect MR arthrography remains faulty, because exact demarcation of degenerative change and partial rupture is difficult. On the basis of the above findings, we do not recommend indirect MR arthrography on patients for whom rotator cuff disease is suspected clinically.

GATE: a simulation toolkit for PET and SPECT.

Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to achieve a modular, versatile, scripted simulation toolkit adapted to the field of nuclear medicine. In particular, GATE allows the description of time-dependent phenomena such as source or detector movement, and source decay kinetics. This feature makes it possible to simulate time curves under realistic acquisition conditions and to test dynamic reconstruction algorithms. This paper gives a detailed description of the design and development of GATE by the OpenGATE collaboration, whose continuing objective is to improve, document and validate GATE by simulating commercially available imaging systems for PET and SPECT. Large effort is also invested in the ability and the flexibility to model novel detection systems or systems still under design. A public release of GATE licensed under the GNU Lesser General Public License can be downloaded at http:/www-lphe.epfl.ch/GATE/. Two benchmarks developed for PET and SPECT to test the installation of GATE and to serve as a tutorial for the users are presented. Extensive validation of the GATE simulation platform has been started, comparing simulations and measurements on commercially available acquisition systems. References to those results are listed. The future prospects towards the gridification of GATE and its extension to other domains such as dosimetry are also discussed.

Assessment of ulnar variance: a radiological investigation in a Dutch population.

OBJECTIVE: A radiological study was performed to evaluate ulnar variance in 68 Dutch patients using an electronic digitizer compared with Palmer's concentric circle method. Using the digitizer method only, the effect of different wrist positions and grip on ulnar variance was then investigated. Finally the distribution of ulnar variance in the selected patients was investigated also using the digitizer method. DESIGN AND PATIENTS: All radiographs were performed with the wrist in a standard zero-rotation position (posteroanterior) and in supination (anteroposterior). Palmer's concentric circle method and an electronic digitizer connected to a personal computer were used to measure ulnar variance. The digitizer consists of a Plexiglas plate with an electronically activated grid beneath it. A radiograph is placed on the plate and a cursor activates a point on the grid. Three plots are marked on the radius and one plot on the most distal part of the ulnar head. The digitizer then determines the difference between a radius passing through the radius plots and the ulnar plot. RESULTS AND CONCLUSIONS: Using the concentric circle method we found an ulna plus predominance, but an ulna minus predominance when using the digitizer method. Overall the ulnar variance distribution for Palmer's method was 41.9% ulna plus, 25.7% neutral and 32.4% ulna minus variance, and for the digitizer method was 40.4% ulna plus, 1.5% neutral and 58.1% ulna minus. The percentage ulnar variance greater than 1 mm on standard radiographs increased from 23% to 58% using the digitizer, with maximum grip, clearly demonstrating the (dynamic) effect of grip on ulnar variance. This almost threefold increase was found to be a significant difference. Significant differences were found between ulnar variance when different wrist positions were compared.

Prevalence, incidence, management, and predictors of venous ulcers in the long-term-care population using the MDS.

OBJECTIVE: To describe the prevalence, incidence, management, and predictors of venous ulcers in residents of certified long-term-care facilities using the Minimum Data Set. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: 32,221 residents admitted to long-term-care facilities in Missouri between January 1, 1996, and October 30, 1998. MAIN OUTCOME MEASURES: Version 2.0 of the Minimum Data Set was utilized. Assessment items included selected measures from background information, disease diagnoses, physical functioning and structural problems, health conditions, oral/nutritional status, and skin condition. MAIN RESULTS: Venous ulcer prevalence on admission was 2.5%. The incidence of venous ulcer development for long-term-care residents admitted without an ulcer at 90, 180, 270, and 365 days after admission was 1.0%, 1.3%, 1.8%, and 2.2%, respectively. The most frequent skin treatments for residents with a venous ulcer were ulcer care, dressings, and ointments. Factors associated with venous ulcer development within a year of admission were diabetes mellitus, peripheral vascular disease, and edema. CONCLUSION: Venous ulcer prevalence and incidence are greater in the long-term-care population than in the community at-large. Residents with a venous ulcer are likely to have comorbid conditions such as diabetes mellitus, peripheral vascular disease, congestive heart failure, edema, wound infection, and pain. Based on these data, risk factors such as history of leg ulcers, recent edema, diabetes mellitus, congestive heart failure, or peripheral vascular disease should prompt clinicians to carefully plan care that will manage a resident's risk for venous ulcer development.

Access to health care resources for family caregivers of elderly persons with dementia.

Concerns about the "elder care crisis" and changes in the provision of health care are fostering expectations that families should be responsible for taking care of their elderly members. The assumptions that families (1) are not providing enough care, (2) know how to provide care, and (3) have access to resources for the provision of care are embedded in the social expectation of family care for elderly persons with dementia. However, research shows that these assumptions are not based on fact.

Special care units for people with Alzheimer's disease. Only for the privileged few?

The number of Special Care Units (SCUs) for people with Alzheimer's disease (AD) in nursing homes have increased dramatically in the past 10 years. Despite the rapid increase in number of SCUs and the concern that most SCUs report higher costs than traditional nursing home units where residents with AD are integrated with cognitively intact residents, the evaluation of costs has been largely unsystematic and noncomparative. Studies are urgently needed to assess comparative costs so that administrators and policy makers can make informed decisions. This article reviews studies that examine the costs of care in SCUs and presents cost-related data comparing the outcomes of care for residents with AD on a SCU and on traditional units in one long-term care setting.

Enamel microstructure in Lemuridae (Mammalia, Primates): assessment of variability.

This study describes the molar enamel microstructure of seven lemurid primates: Hapalemur griseus, Varecia variegata, Lemur catta, Lemur macaco, Lemur fulvus rufus, Lemur fulvus fulvus, and Lemur fulvus albifrons. Contrary to earlier accounts, which reported little or no prism decussation in lemurid enamel, both Lemur and Varecia molars contain a prominent inner layer of decussating prisms (Hunter-Schreger bands), in addition to an outer radial prism layer, and a thin, nonprismatic enamel surface layer. In contrast, Hapalemur enamel consists entirely of radial and, near the surface, nonprismatic enamel. In addition, for all species, prism packing patterns differ according to depth from the tooth surface, and for all species but Varecia (which also has the thinnest enamel of any lemurid), average prism area increases from the enamel-dentine junction to the surface; this may be a developmental solution to the problem of accommodating a larger outer surface area with enamel deposited from a fixed number of cells. Finally, contradicting some previous reports, Pattern 1 prisms predominate only in the most superficial prismatic enamel. In the deeper enamel, prism cross-sections include both closed (Pattern 1) and arc-shaped (Pattern 2 or, most commonly, Pattern 3). This sequence of depth-related pattern change is repeated in all taxa. It should also be emphasized that all taxa can exhibit all three prism patterns in their mature enamel. The high degree of quantitative and qualitative variation in prism size, shape, and packing suggests that these features should be used cautiously in phylogenetic studies. Hapalemur is distinguished from the other lemurids by unique, medially constricted or rectangular prism cross-sections at an intermediate depth and the absence of prism decussation, but, without further assessment of character polarity, these differences do not clarify lemurid phylogenetic relations. Some characters of enamel microstructure may represent synapomorphies of Lemuridae, or of clades within Lemuridae, but homoplasty is likely to be common. Homoplasy of enamel characters may reflect functional constraints.

Critical issues for the development of clinical nursing knowledge.

This article reviews the other articles in this issue that provide evidence of recent progress in clinical nursing research. The authors, guest editors of this issue, issue a call for further research to develop improvements in clinical nursing practice.

A model of organizational power: analysis and significance to nursing.

In this article a causal model of the process of interorganizational power is presented with results of one test using survey data from 39 non-nursing organizations. The model argues that interaction strategies of organizations are outcomes of the relative basis and use of resources in interorganizational transactions. Multiple regression and multiple-partial correlation analyses were used to analyze the data. The findings partially support the model and indicate that it holds promise for development and refinement. Conclusions are that the model should be tested with nursing organizations and used to conceptualize additional aspects of the power process that nursing can foster.

Organizational characteristics that facilitate the use of nursing diagnoses.

The effective use of nursing diagnosis is facilitated by an organizational structure that accommodates nursing professional autonomy and accountability. Nurse executives who plan for the implementation of nursing diagnosis should expect nurses to develop as an autonomous and accountable collective. There should be shared leadership to achieve mutual goals, make decisions about nursing practice, socialize its members, build and maintain effective communication processes, and use the process of change to effect and maintain the model of practice. When these structures and processes compose the organizational milieu, nursing diagnoses will be used and will promote the further development of nurses as autonomous and accountable professionals who develop and use knowledge to deliver quality client care.