CT-like images based on T1-weighted gradient echo MRI sequences for the assessment of fractures of the hand and wrist compared to CT.

OBJECTIVE: To evaluate the performance of a 3D T1-weighted gradient-echo (3D T1GRE) computed tomography (CT)-like magnetic resonance imaging (MRI) sequence for detecting and assessing wrist and hand fractures compared to conventional CT. METHODS: Subjects with acute wrist or hand fracture in CT underwent additional 3 T MRI including a CT-like 3D T1GRE sequence and were compared to patients without fractures. Two radiologists assessed fracture morphology on both modalities according to the Arbeitsgemeinschaft Osteosynthese (AO) and graded image quality and diagnostic confidence on a 5-point Likert scale. Besides diagnostic test evaluation, differences in image quality and diagnostic confidence between CT-like MRI and CT were calculated using the Wilcoxon test. Agreement of AO classification between modalities and readers was assessed using Cohen's Kappa. RESULTS: Twenty-eight patients with 43 fractures and 43 controls were included. Image quality (3D T1GRE 1.19 ± 0.37 vs. CT 1.22 ± 0.42; p = 0.65) and diagnostic confidence (3D T1GRE 1.28 ± 0.53 vs. CT 1.28 ± 0.55; p = 1.00) were rated excellent for both modalities. Regarding the AO classification, intra- (rater 1 and rater 2, κ = 0.89; 95% CI 0.80-0.97) and interrater agreement were excellent (3D T1GRE, κ = 0.82; 95% CI, 0.70-0.93; CT, κ = 0.85; 95% CI, 0.75-0.94). CT-like MRI showed excellent sensitivity, specificity and accuracy for fracture detection (reader 1: 1.00, 0.92, 0.96; reader 2: 0.98, 0.94, 0.96). CONCLUSION: CT-like MRI is a comparable alternative to CT for assessing hand and wrist fractures, offering the advantage of avoiding radiation exposure.

[Pathologies of the shoulder joint : Anatomy and examination techniques]. / Pathologien des Schultergelenks : Anatomie und Untersuchungstechniken.

CLINICAL ISSUE: The movements and stability of the human shoulder are a complex dynamic interaction between several joints, muscles and ligaments, which on the one hand enable extensive mobility and on the other hand must provide the necessary stability. Furthermore, the complexity of the shoulder is increased by a large number of normal variants. This article aims to explain the relevant anatomical structures and the radiological examination techniques necessary to visualize them. STANDARD RADIOLOGICAL PROCEDURES: Various modalities contribute to the examination of the shoulder. These include X­rays, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound. METHODOLOGICAL INNOVATION: It is important to use the various procedures appropriately. Especially with MRI arthrography, it is necessary to pay attention to suitable sequences and possibly additional examination positions. PRACTICAL RECOMMENDATION: The multimodal examination of the shoulder can contribute to the diagnosis of numerous clinical pictures. Anatomical and methodological foundations are essential for this.

A step closer to continuous buffer preparation from solids: Predicting powder compaction and how to prevent it.

The preparation of buffer solutions used in the biopharmaceutical industry is typically performed manually by the addition of one or multiple buffering reagents to water. Recently, the adaptation of powder feeders for continuous solid feeding was demonstrated for continuous buffer preparation. However, the intrinsic characteristics of powders can change the stability of the process, due to the hygroscopic nature of some substances and humidity-induced caking and compaction behavior, but there is no simple and easy methodology available for predicting this behavior for buffer species. To predict which buffering reagents are suitable without special precautions and investigate their behavior, force displacement measurements were conducted with a customized rheometer over 18 h. While most of the eight investigated buffering reagents indicated uniform compaction, especially sodium acetate and dipotassium hydrogen phosphate (K2HPO4) showed a significant increase in yield stress after 2 h. Experiments conducted with a 3D printed miniaturized screw conveyor confirmed the increased yield stress measurements by visible compaction and failure of the feeding. By taking additional precautions and adjusting the design of the hopper, we demonstrated a highly linear profile of all buffering reagents over a duration of 12 and 24 h. We showed that force displacement measurements accurately predict the behavior of buffer components in continuous feeding devices for continuous buffer preparation and are a valuable tool to identify buffer components that need special precautions. Stable, precise feeding of all tested buffer components was demonstrated, highlighting the importance of identifying buffers that need a specialized setup with a rapid methodology.

[Sports-related injuries of the thumb and fingers]. / Sportverletzungen des Daumens und der Finger.

Finger and thumb injuries are common in established and trend sports. Imaging plays an important role in acute trauma care, further therapy planning, and ultimately for a rapid return to play. Sound knowledge of the complex anatomy of the fingers and thumb is indispensable for accurate diagnosis. This article presents the ligament anatomy of the metacarpophalangeal and interphalangeal joints of the finger and the thumb, the extensor and flexor tendon apparatus, and the diagnosis of typical sports injuries using x­rays and magnetic resonance imaging. Furthermore, imaging findings of typical sports-associated injuries are illustrated.

[The ulnocarpal complex : New clinical and radiological considerations]. / Der ulnokarpale Komplex : Neue klinische und radiologische Überlegungen.

CLINICAL ISSUE: The triangular fibrocartilage complex (TFCC) is an anatomically complex structure with high demands on spatial and contrast resolution in imaging. RADIOLOGICAL METHODS: The central, predominantly avascular articular disc can be distinguished from the ligamentous, vascularized periphery. Imaging methods include magnetic resonance imaging (MRI, preferably contrast-enhanced) as well as MR and computed tomography (CT) arthrography. DIAGNOSTIC INNOVATIONS: While high-resolution MRI represents the standard diagnostic tool for the TFCC in general, arthrographic imaging is particularly useful for assessment of the foveal (proximal) lamina of the TFCC. In radiological reporting, the convergence of the TFCC periphery towards the ulnar styloid process and the ulnar fovea must be considered. ACHIEVEMENTS: The Palmer classification is suitable for evaluating lesions of the articular disc, whereas the Atzei classification is superior for lesions of the ulnar TFCC insertions. PRACTICAL RECOMMENDATION: Use of a high-resolution examination technique and anatomy-based image interpretation are important for reliable MRI of the TFCC.

[Developmental neurology - networked medicine and new perspectives]. / Entwicklungsneurologie ­ vernetzte Medizin und neue Perspektiven.

Developmental neurology is one of the major areas of neuropediatrics and is among other things (legally) responsible for monitoring the motor, cognitive and psychosocial development of all infants using standardized monitoring investigations. The special focus is on infants born at risk and/or due to premature birth before 32 weeks of gestation or a birth weight less than 1500 g. Early diagnosis of deviations from normal, age-related development is a prerequisite for early interventions, which may positively influence development and the long-term biopsychosocial prognosis of the patients. This article illustrates the available methods in developmental neurology with a focus on recent developments. Particular attention is paid to the predictive value of general movements (GM). The current development of markerless automated detection of spontaneous movements using conventional depth imaging cameras is demonstrated. Differences in spontaneous movements in infants at the age of 12 weeks are illustrated and discussed exemplified by three patients (healthy versus genetic syndrome versus cerebral palsy).

Incidence and impact of herpes simplex and cytomegalovirus detection in the respiratory tract after lung transplantation.

Herpesvirus infections cause morbidity in lung transplant recipients. The study was conducted to investigate the incidence and impact of herpes simplex virus (HSV) and cytomegalovirus (CMV) detection in the respiratory tract (RT) of lung and heart-lung transplant recipients (LTR) during the postoperative phase. In a prospective cohort study, 91 LTR having at least 1 nasopharyngeal swab (NPS) sent for virus diagnostics were monitored for CMV and HSV detection in NPS during their post-transplant hospital stay on cardiothoracic surgery wards (median 4 weeks) by direct immunofluorescence testing for HSV, virus culture, and CMV and HSV polymerase chain reaction (PCR). Bronchoalveolar lavages (BALs) were analyzed with the same protocol except that HSV PCR was only performed on request. Risk factor analysis for the outcome '90-day mortality' was performed. Fifteen LTR had virus detection in NPS (16.5%): 9 had CMV, 5 had HSV, and 1 had both CMV and HSV. Four of 84 LTR had CMV detection in BAL (4.8%). Absence of CMV detection in NPS had a negative predictive value of 98.8% for absence of CMV detection in BAL. HSV DNA detection in NPS, especially if detected within 8 days after transplantation, was associated with 90-day mortality. In conclusion, detection of herpesviruses in the RT was clinically relevant and frequent, despite antiviral prophylaxis.

Social differences in illness and health-related exclusion from the labour market in Denmark from 1987 to 1994.

OBJECTIVE: The objectives were first to analyse differences in long-standing illness, limiting long-standing illness, and perceived health as below good in relation to different indicators of social class over time; and secondly to analyse the association of long-standing illness, educational level, age, and gender with employment status. SUBJECTS AND METHODS: Self-reported information on illness, educational level, employment status, and occupational class was obtained in two nationally representative Danish health interview surveys in 1987 (n=4753) and 1994 (n=4668). RESULTS: There was a marked increase in long-standing illness from 1987 (33%) to 1994 (38%), especially among women with higher education (13% in 1987 to 26% in 1994). The prevalence of perceived health below good was unchanged (c. 20%) during the same period. Among employed men in 1987 the lowest prevalence of long-standing illness was seen in upper salaried employees (21%) and the highest in skilled workers (35%). In 1994, the difference had diminished and the prevalence rates for the same classes were 28% and 29%, respectively. Among employed women, a similar pattern was seen. The lowest rate in 1987 was seen among self-employed with subordinates (15%) and the highest in self-employed without subordinates (28%). In 1994, the difference was reduced with prevalence rates of 23% and 32%, respectively. In addition, substantial differences in health status between groups with different educational backgrounds were found. The proportion of the population with long-standing illnesses was clearly higher in the group with low education compared with the group with high education. A similar social gradient was found for perceived health as below good. Those with the highest odds ratio of being a disability pensioner are women with long-standing illness, only basic education, and above 55 years of age. CONCLUSION: In conclusion, the study showed that the prevalence of long-standing illness increased from the mid-1980s to the mid-1990s, whereas perceived health below good was unchanged. In 1994, there was a remarkable difference in health between employed and non-employed people, indicating a health-related exclusion from the labour market. This may explain why, in 1994, smaller occupational class differences were found in the prevalence of long-standing illness among employed people compared with the findings in 1987, whereas the health differences remained in the different educational groups. Women above 54 years of age with basic education only and long-standing illness have the highest odds ratio of permanent exclusion from the labour market.

Analysis of edge-losses in reflectance measurements of pigmented maxillofacial elastomer.

Edge-losses occur during reflectance measurements of pigmented maxillofacial elastomer when light is scattered within a sample beyond that part of the surface exposed to the observation system of the optical device. A custom sample-holder is presented which redirects light that would not be measured during conventional reflectance measurement back into the sample. The amount of edge-loss occurring within thin layers of maxillofacial elastomer with tan pigment on black-and-white backings was found to depend on sample thickness, the backing, the beam size used during conventional reflectance measurement, and the optical term bS = (2KS + K2)1/2. Data analysis revealed a significant interaction among these four factors. Additionally, the edge-loss occurring during the tristimulus reflectance measurement of thick samples of maxillofacial elastomer with various concentrations of tan and black pigment was found to be linearly related to bS up to a limiting value, with no additional edge-loss occurring for bS values above this limiting value. Edge-loss is an important consideration during the matching of the optical characteristics of pigmented maxillofacial material to those of human skin.

The relationship between elastomer opacity, colorimeter beam size, and measured colorimetric response.

The effect of opacity on the colorimetric responses of large-area and small-area colorimeters was determined using an elastomer intended for maxillofacial prosthetics use and containing various pigments at different concentrations. Opacity was determined by calculating the contrast ratio of 2-mm-thick specimens against black and white backings, using Kubelka-Munk analyses to correct for thickness and backing color variations. The measure of comparison of the two colorimeters was the relative difference in tristimulus reflectance, with the tristimulus reflectance of the large-area colorimeter as the basis of the relative difference. A significant quadratic relationship was found between contrast ratio and the relative difference in tristimulus reflectance. This relationship may be used to describe opacity without the need to make optical observations or measurements of a thin layer of material on contrasting backings. The small-area colorimeter produced color parameters that are a measure of the combined effects of both color and opacity. The importance of beam size considerations of optical measuring devices for translucent natural and prosthetic materials was emphasized.