High-energy x-ray Talbot-Lau radiography of a human knee.

We report on a radiographic measurement of an ex vivo human knee using a grating-based phase-contrast imaging setup and a medical x-ray tube at a tube voltage of 70 kV. The measurement has been carried out using a Talbot-Lau setup that is suitable to achieve a high visibility in the energy regime of medical imaging. In a medical reading by an experienced trauma surgeon signatures of chondrocalcinosis in the medial meniscus have been identified more evidently using the dark-field image in comparison to the conventional attenuation image. The analysis has been carried out at various dose levels down to 0.14 mGy measured as air kerma, which is a dose comparable to clinically used radiographic devices. The diagnosis has been confirmed by a histological analysis of the meniscus tissue. In the introduced high-frequency filtered phase-contrast image the anterior and posterior horn of the medial meniscus and the posterior cruciate ligament have also been visible. Furthermore, atherosclerotic plaque is visible in both imaging modalities, attenuation and dark-field, despite the presence of overlaying bone. This measurement, for the first time, proves the feasibility of Talbot-Lau x-ray imaging at high-energy spectra above 40 kVp and reasonable dose levels with regard to spacious and dense objects.

Motion compensation for cone-beam CT using Fourier consistency conditions.

In cone-beam CT, involuntary patient motion and inaccurate or irreproducible scanner motion substantially degrades image quality. To avoid artifacts this motion needs to be estimated and compensated during image reconstruction. In previous work we showed that Fourier consistency conditions (FCC) can be used in fan-beam CT to estimate motion in the sinogram domain. This work extends the FCC to [Formula: see text] cone-beam CT. We derive an efficient cost function to compensate for [Formula: see text] motion using [Formula: see text] detector translations. The extended FCC method have been tested with five translational motion patterns, using a challenging numerical phantom. We evaluated the root-mean-square-error and the structural-similarity-index between motion corrected and motion-free reconstructions. Additionally, we computed the mean-absolute-difference (MAD) between the estimated and the ground-truth motion. The practical applicability of the method is demonstrated by application to respiratory motion estimation in rotational angiography, but also to motion correction for weight-bearing imaging of knees. Where the latter makes use of a specifically modified FCC version which is robust to axial truncation. The results show a great reduction of motion artifacts. Accurate estimation results were achieved with a maximum MAD value of 708 µm and 1184 µm for motion along the vertical and horizontal detector direction, respectively. The image quality of reconstructions obtained with the proposed method is close to that of motion corrected reconstructions based on the ground-truth motion. Simulations using noise-free and noisy data demonstrate that FCC are robust to noise. Even high-frequency motion was accurately estimated leading to a considerable reduction of streaking artifacts. The method is purely image-based and therefore independent of any auxiliary data.

Optimisation of image reconstruction for phase-contrast x-ray Talbot-Lau imaging with regard to mechanical robustness.

X-ray grating-based phase-contrast imaging opens new opportunities, inter alia, in medical imaging and non-destructive testing. Because, information about the attenuation properties and about the refractive properties of an object are gained simultaneously. Talbot-Lau imaging requires the knowledge of a reference or free-field image. The long-term stability of a Talbot-Lau interferometer is related to the time span of the validity of a measured reference image. It would be desirable to keep the validity of the reference image for a day or longer to improve feasibility of Talbot-Lau imaging. However, for example thermal and other long-term external influences result in drifting effects of the phase images. Therefore, phases are shifting over time and the reference image is not valid for long-term measurements. Thus, artifacts occur in differential phase-contrast images. We developed an algorithm to determine the differential phase-contrast image with the help of just one calibration image, which is valid for a long time-period. With the help of this algorithm, called phase-plane-fit method, it is possible to save measurement-time, as it is not necessary to take a reference image for each measurement. Additionally, transferring the interferometer technique from laboratory setups to conventional imaging systems the necessary rigidity of the system is difficult to achieve. Therefore, short-term effects like vibrations or distortions of the system lead to imperfections within the phase-stepping procedure. Consequently, artifacts occur in all three image modalities (differential phase-contrast image, attenuation image and dark-field image) of Talbot-Lau imaging. This is a problem with regard to the intended use of phase-contrast imaging for example in clinical routine or non-destructive testing. In this publication an algorithm of Vargas et al is applied and complemented to correct inaccurate phase-step positions with the help of a principal component analysis (PCA). Thus, it is possible to calculate the artifact free images. Subsequently, the whole algorithm is called PCA minimization algorithm.

Outcome data from the LEAP (Live, Eat and Play) trial: a randomized controlled trial of a primary care intervention for childhood overweight/mild obesity.

OBJECTIVES: To reduce gain in body mass index (BMI) in overweight/mildly obese children in the primary care setting. DESIGN: Randomized controlled trial (RCT) nested within a baseline cross-sectional BMI survey. SETTING: Twenty nine general practices, Melbourne, Australia. PARTICIPANTS: (1) BMI survey: 2112 children visiting their general practitioner (GP) April-December 2002; (2) RCT: individually randomized overweight/mildly obese (BMI z-score <3.0) children aged 5 years 0 months-9 years 11 months (82 intervention, 81 control). INTERVENTION: Four standard GP consultations over 12 weeks, targeting change in nutrition, physical activity and sedentary behaviour, supported by purpose-designed family materials. MAIN OUTCOME MEASURES: Primary: BMI at 9 and 15 months post-randomization. Secondary: Parent-reported child nutrition, physical activity and health status; child-reported health status, body satisfaction and appearance/self-worth. RESULTS: Attrition was 10%. The adjusted mean difference (intervention-control) in BMI was -0.2 kg/m(2) (95% CI: -0.6 to 0.1; P=0.25) at 9 months and -0.0 kg/m(2) (95% CI: -0.5 to 0.5; P=1.00) at 15 months. There was a relative improvement in nutrition scores in the intervention arm at both 9 and 15 months. There was weak evidence of an increase in daily physical activity in the intervention arm. Health status and body image were similar in the trial arms. CONCLUSIONS: This intervention did not result in a sustained BMI reduction, despite the improvement in parent-reported nutrition. Brief individualized solution-focused approaches may not be an effective approach to childhood overweight. Alternatively, this intervention may not have been intensive enough or the GP training may have been insufficient; however, increasing either would have significant cost and resource implications at a population level.

Training to enhance partnerships between mental health professionals and family caregivers: a comparative study.

A training program for mental health staff was collaboratively developed and delivered by family caregivers and professionals. It addressed calls for less blaming attitudes toward families and increased contact between professionals and families. Two levels of training were compared. Twenty-seven staff members completed a 30-hour extended 12-week program. Eighty-two percent of all eligible staff from area teams attended a brief program involving three or six hours of training. Self-ratings of competence and attitudes toward families improved only for staff receiving extended training. Contacts with families increased for those in the extended program but not for all types of teams, suggesting that length of training and service type may limit the impact of training.

Episodic cluster headache in a community: clinical features and treatment.

OBJECTIVE: To study the clinical features and treatment given to episodic cluster headache patients in the Calgary region. PATIENTS: Fifty-one (51) patients who responded to a media campaign, had previously been diagnosed by their family physicians, and who met International Headache Society (IHS) criteria for episodic cluster headache, formed the population for this study. METHODS: The media campaign consisted of newspaper advertisements and radio publicity including physician interviews and talk shows. Patients were required to complete by 200-item questionnaire detailing clinical features and treatment of their cluster headache syndrome. Each patient was also interviewed by our research nurse for clarification and proper completion of questionnaire. RESULTS: Fifty-one percent (51%) of our patients had short headache attacks lasting one hour or less. Almost one-half (45%) had three or four attacks per 24 hour period. Eighty-six percent (86%) had been referred to a neurologist. Sixty-nine percent (69%) had never used oxygen, but of those who had, one-half were still using it. Sumatriptan by injection had been tried by 26% of patients and of these, 93% considered it effective. Subcutaneous dihydroergotamine had been tried by 8%. For prophylaxis, 41% had tried methysergide, 31% prednisone, and 4% verapamil. Many patients had been prescribed migraine prophylactic drugs which are ineffective for cluster headache, and some had also undergone dental procedures or nasal and sinus surgeries. CONCLUSIONS: Many cluster headache patients had not, to their knowledge, been prescribed or used the best symptomatic and prophylactic treatments for cluster headache. This should be addressed through educational programs and through making up-to-date information on the treatment of cluster headache readily available to physicians and patients.

Monitoring of r-hirudin anticoagulation during cardiopulmonary bypass--assessment of the whole blood ecarin clotting time.

The use of recombinant (r) hirudin as an anticoagulant in performing extracorporeal circulation systems including cardiopulmonary bypass (CPB) devices requires a specific and easy to handle monitoring system. The usefulness of the celite-induced activated clotting time (ACT) and the activated partial thromboplastin time (APTT) for r-hirudin monitoring has been tested on ex vivo blood samples obtained from eight patients treated with r-hirudin during open heart surgery. The very poor relationship between the prolongation of the ACT and APTT values and the concentration of r-hirudin as measured using a chromogenic factor IIa assay indicates that both assays are not suitable to monitor r-hirudin anticoagulation. As an alternative approach a whole blood clotting assay based on the prothrombin-activating snake venom ecarin has been tested. In vitro experiments using r-hirudin-spiked whole blood samples showed a linear relationship between the concentration of hirudin added and the prolongation of the clotting times up to a concentration of r-hirudin of 4.0 micrograms/ml. Interassay coefficients (CV) of variation between 2.1% and 5.4% demonstrate the accuracy of the ecarin clotting time (ECT) assay. Differences in the interindividual responsiveness to r-hirudin were analyzed on r-hirudin-spiked blood samples obtained from 50 healthy blood donors. CV-values between 1.8% and 6% measured at r-hirudin concentrations between 0.5 and 4 micrograms/ml indicate remarkably slight differences in r-hirudin responsiveness. ECT assay results of the ex vivo blood samples linearily correlate (r = 0.79) to the concentration of r-hirudin. Moreover, assay results were not influenced by treatment with aprotinin or heparin. These findings together with the short measuring time with less than 120 seconds warrant the whole blood ECT to be a suitable assay for monitoring of r-hirudin anticoagulation in cardiac surgery.

Effectiveness of subcutaneous dihydroergotamine by home injection for migraine.

The effectiveness of dihydroergotamine administered by home subcutaneous injection by the patient or family for severe headache attacks was assessed retrospectively in 51 patients. Average follow-up was 21 weeks. Twenty-one patients had intermittent migraine attacks, 27 had transformed migraine with chronic daily headache, and 3 had chronic tension-type headache. Of the 51 patients taught home injection, 35% had an excellent overall response, 18% had a good response, 12% had a poor response but continued to use dihydroergotamine, and 35% had discontinued dihydroergotamine use. Side effects were the main reason for stopping dihydroergotamine. These included nausea or vomiting or both, limb pain or numbness or both, chest or throat tightness or both, and soreness at the injection site. Thirty-three patients (65%) continued to use dihydroergotamine at the end of the follow-up period. In patients who previously required injections from medical personnel for headache crises and in whom home injection of dihydroergotamine was effective, a dramatic reduction occurred in hospital emergency room and physician office utilization. Dihydroergotamine use by home injection can be an effective treatment for a significant proportion of patients with severe migraine including patients with transformed migraine and medication overuse.

The extracellular matrix in human cardiac tissue. Part II: Vimentin, laminin, and fibronectin.

In continuation of our previous work describing the localization of the collagens type I, III, VI, and IV the present study describes the localization of vimentin, laminin, and fibronectin in human myocardium obtained as left ventricular needle biopsies during cardiac surgery. Myocardium from normal pigs served for comparison. Monoclonal antibodies against the various proteins were used on frozen sections, labeled with fluorescein and viewed in the fluorescence microscope. Vimentin, the intermediate filament of mesenchymal cells, is present in fibroblasts, fibrocytes, and endothelial cells. Laminin is observed in the basal membrane of myocytes, smooth muscle and endothelial cells. The staining intensity for the B1-chain is higher in and around myocytes as compared with the B2-chain antibody, but more blood vessels were stained with the latter. The antibody against the A-chain only stained the basal lamina of vascular cells but not that of myocytes. Fibronectin was localized homogeneously throughout the extracellular space as matrix material in which the cellular elements and the various other proteins such as collagens are embedded. Intracellular staining in myocytes (T-tubules) was commonly observed. Both parts of this study show the distribution of extracellular proteins in normal human cardiac tissue and are intended to be the basis for investigations of pathological changes in diseased human myocardium.

The extracellular matrix in human myocardium: Part I: Collagens I, III, IV, and VI.

The composition of the extracellular matrix in normal human myocardium obtained at open-heart surgery was investigated using monoclonal antibodies against the collagens I, III, IV, and VI, and fluorescence microscopy. The aim of the study was to provide information on normal myocardium that could be used in the evaluation of pathological changes. Porcine myocardium was used for comparison, and both tissues showed a perfect agreement of the results, apart from collagen IV. This was negative in pig myocardium, due to the species specificity of the antibody. Collagens I and III were localized in the extracellular space as either coarse or fine fibrillar structures; the cellular elements of the interstitium, except for the endothelial cells, were also stained. Labeling for collagen VI was much finer than for the other collagens, and was present throughout the interstitium. Collagen IV stained the basement membranes of myocytes and capillary endothelial cells, and also labeled the T-tubular system in the myocytes. The second part of this communication will describe the localization of fibronectin, laminin and vimentin in normal human myocardium.

[Neoplastic ulcus cruris. Spinocellular carcinoma of the left lower leg with lymph node metastases of the popliteal, inguinal and iliac areas]. / Neoplastisches Ulcus cruris. Carcinoma spinocellulare des linken Unterschenkels mit Lymphknotenmetastasen popliteal, inguinal und iliakal.

A 71-year-old patient has suffered from a chronic leg ulcer of venous origin for 12 years. Biopsy of swollen inguinal lymph nodes revealed a metastasis of a squamous cell carcinoma. The primary tumor was located and histologically verified in the leg ulcer.

[Questionable significance of the chemical analysis of a single 24-hour urine sample in recurrent calcium oxalate nephrolithiasis]. / Fragliche Aussagekraft der chemischen Analyse eines einzelnen 24 h-Urins bei rezidivierender Kalziumoxalat-Nephrolithiasis.

Chemical findings were obtained from 24 h urine samples of 43 male calcium-oxalate stone-formers on an unrestricted diet. Results were compared with data from 51 age-matched healthy blood donors. No differences were found in the excreted quantities of calcium, oxalic acid, uric acid and inorganic phosphate, nor in the calcium to creatinine ratio or the activity product of calcium and oxalic acid. The only differences were a higher output of magnesium and a higher magnesium to calcium ratio for controls. The extent of these differences, however, does not justify further subdivision of the group of stone-formers. The diagnostic and therapeutic significance of the chemical analysis of one 24 h urine sample is doubtful for this group of patients.