Biomedical subjects

H-J Mentzel

Publications and source records attributed to H-J Mentzel.

9 recordsLinked to original sources

PubMed2006

Multiple reversible MR signal changes caused by Epstein-Barr virus encephalitis.

This report presents the imaging findings of an unusual case of Epstein-Barr virus (EBV) encephalitis. A young man presented with a short-lasting history of febrile infection, neuropsychologic deficits, ataxia, and seizures. MR imaging revealed fully reversible signal intensities (T2, diffusion-weighted imaging with a decreased apparent diffusion coefficient) in the splenium of the corpus callosum and both posterior hemispheres. EBV infection must be added to the list of differential diagnoses of (reversible) splenial lesions.

Adult↗

PubMed2005

[Influence of body constitution on bone mineral density measured by digital radiogrammetry].

PURPOSE: In addition to many established osteodensitometric techniques, digital radiogrammetry (DXR) is considered to be a reliable method for measuring the cortical bone mineral density (DXR-BMD). This study investigates the influence of body constitution on BMD of healthy adults as calculated by DXR. MATERIALS AND METHODS: In a prospective study, 246 adults without bone affecting diseases in their clinical history underwent DXR for analysis and calculations of bone mineral density and determination of metacarpal index (MCI) and porosity index (PI). Height, weight and body mass index (BMI) were recorded for each patient. RESULTS: For all individuals and for all BMI subgroups, both height (0.55 < R < 0.70, p < 0.01) and body weight (0.56 < R < 0.78, p < 0.01) correlated closely with DXR-BMD. Only in the over-weight group, no significant correlation was found between body weight and DXR-BMD. In addition, a significant reduction of the relative DXR-BMD and MCI values was observed between the over-weight and the under-weight group as well as between normal-weight and under-weight individuals (p < 0.01). Otherwise, cortical porosity decreased with increasing body weight. CONCLUSION: Similar to Dual Energy X-ray Absorptiometry-based studies (DXA), digital radiogrammetry measures an increase in BMD with increasing body weight. Therefore DXR, which provides a precise technique without influence of soft tissue, seems to be a promising technique for quantifying marginal alterations in cortical BMD as well for following the course of osteoporosis.

Absorptiometry, Photon↗

PubMed2005

[Procalcitonin as a marker for severe sepsis in an immunosuppressed patient].

A 22 year old female was admitted to the emergency department with high fever up to 41,5 degrees C, tachycardia, and arterial hypotension. Clinically, she presented with bilateral pulmonary coarse crackles. Diagnosis on admission was pneumonia with septic shock. Intriguingly, procalcitonin (PCT) was increased early, reaching up to 435 ng/mL, while C-reactive protein levels were only moderately increased, with several days delay. The sepsis was originated from a multi-resistant pseudomonas aeruginosa pneumonia. Remarkably, the course of PCT levels reflected the severity of septic shock in that it paralleled noradrenaline demand. Ten months previously, the patient had been diagnosed with acute disseminated brainstem encephalitis (ADEM), and had received two cycles of intravenous cyclophosphamide. Our case illustrates that PCT is an early marker for sepsis and it indicates that PCT may also be a valuable marker for the severity of sepsis in immunosuppressed patients.

Adult↗

PubMed2005

[The effect of sports activities in children and adolescents on the calcaneus--an investigation with quantitative ultrasound].

PURPOSE: To determine whether quantitative ultrasound (QUS) parameters speed of sound (SOS) and broadband ultrasound attenuation (BUA) on the calcaneus are different between athletic children and a reference population. PATIENTS AND METHODS: From a college of physical education, 177 children and adolescents (121 boys and 56 girls, age range from 11 to 18 years) were included in this study. QUS was performed on the calcaneus using the Saharatrade mark device (Hologic, USA). SOS and BUA were estimated. Regional reference values of 3299 children were used to determine significant differences between athletes and reference population. The influence of activitiy level, age, height, and weight was estimated using correlation analysis. RESULTS: Sportsmen showed significant (p < 0.05) higher values of the QUS parameters (SOS 1581.1 m/s; BUA 69.7 dB/MHz) compared to the reference data (SOS 1563.9 m/s; BUA 64.2 dB/MHz). Significant correlation was observed between BUA and the level of activity, age, weight, and height (p < 0.01) and between SOS and weight and height (p < 0.05). In the group of soccer players and athlets, significant correlation was found between BUA vs. age and BUA vs. weight (p < 0.05). Furthermore, significant corelation was observed between BUA vs. age and weight in judokas and wrestlers. For the level of activity, a significant correlation to BUA was only found in the group of judokas and wrestlers (p < 0.01). CONCLUSION: An increase in quantitative ultrasound parameters on the calcaneus occurs in children and adolescents with increased physical activity.

Adolescent↗

PubMed2005

[Assessment of skeletal age using a new ultrasound method].

PURPOSE: Determination of skeletal development in children is important. The most used evaluation method is to study left hand X-ray based on the standards depicted by Greulich and Pyle. The aim of our study was to compare the accuracy of a new sonographically based method with the standard method. MATERIAL AND METHODS: 160 consecutive evaluated children and adolescents (77 male, 83 female) who received a X-ray of the left hand were evaluated. Ultrasound examination of the same hand was performed on the same day using the BonAge system (Sunlight Medical Ltd., Israel). This system evaluates the relationship between the velocity of the wave (speed of sound) passing thorough the distal radial and ulna epiphysis and growth, using gender- and ethnicity-based algorithms. Three experienced investigators (U1-U3) analysed the X-ray and assigned bone age scores based on the Greulich and Pyle atlas (G and P). The investigators were blinded to the calendary age (CA) of the patient and also for the BonAge result. Correlation between BonAge system results and G and P was performed using SPSS 12.0.1. RESULTS: In 152 patients BonAge measurement could be performed successfully. The correlation between the three investigators using the G and P method was between 0.977 and 0.980; correlation between the BonAge system and the investigators (U1-U3) was 0.902 and 0.920. The paired t-test showed no significant differences between the BonAge system and the three investigators and also for the comparison between U1 and U2. There were significant differences between U1 vs. U3 and U2 vs. U3 (p < 0.05). DISCUSSION: The BonAge device demonstrates the ability to produce an sufficient assessment of bone age using an ultrasound method. The results are correlated with conventional skeletal age evaluation using the G and P method. Advantages of the ultrasound device are objectivity, lack of ionizing radiation, and easy accessibility. In the case of first investigation X-ray is necessary to look for dissociated skeletal age, dysplasia, and mineralisation.

Adolescent↗

PubMed2004

[Visualization of symmetric striopallidodentate calcinosis by using high-resolution susceptibility-weighted MR imaging. An account of the impact of different diagnostic methods of M. Fahr].

Bilateral striopallidodentate calcinosis, also known as Fahr's disease, is characterized by symmetric calcifications of the basal ganglia, thalami, dentate nuclei of the cerebellum and white matter of the cerebral hemispheres. Besides the common idiopathic etiology of bilateral intracerebral calcinosis, alterations of calcium metabolism are present in rare cases, which are especially caused by hormonal dysfunction of the parathyroids. Advanced imaging techniques, such as CT and MRI, demonstrate increasing relevance regarding diagnosis of bilateral striopallidodentate calcinosis. Intracranial calcifications are routinely observed with high sensitivity by CT. On MR images calcifications exhibit different signal intensities, which depend on the stage of the disease, differences in calcium metabolism and the compound of these calcifications. Application of a new high-resolution, susceptibility-weighted MR sequence allows detailed visualization of the intracerebral calcifications in Fahr's disease. Further diagnostic methods and important aspects regarding clinical manifestation of bilateral striopallidodentate calcinosis are also discussed.

Basal Ganglia Diseases↗

PubMed2004

[Clinical trial for differentiation between corticoid-induced osteoporosis and periarticular demineralization via digital radiogrammetry in patients suffering from rheumatoid arthritis].

PURPOSE: To investigate a new bone densitometric technology based on digital radiogrammetry (DXR) with respect to its ability to measure severity-dependent variations of bone mineral density (BMD) in patients with rheumatoid arthritis and to differentiate between corticoid-induced and periarticular bone mineral density loss. PATIENTS AND METHODS: A total of 153 randomly selected patients suffering from verified rheumatoid arthritis underwent digitally performed plain radiographs of the non-dominant hand and also measurements of dual-energy X-ray absorptiometry (DXA) regarding total femur and lumbar spine in 102 patients and peripheral quantitative computed tomography (pQCT) regarding the distal radius in 51 patients. Using DXR the radiographs of the non-dominant hand were analyzed for cortical bone mineral density calculation. The severity was classified in the DXA group using the Ratingen score. Furthermore, both study populations were divided into patients with and without corticoid therapy. RESULTS: Correlations between BMD determined by DXR and by DXA (R=0.44 for lumbar spine and R=0.61 for total femur) versus pQCT (0.46<R<0.59) were all significant. An appropriate association was confirmed between pQCT and DXA (R=0.61 for total femur and 0.73 for LWS). In the subgroup of patients with corticoid therapy (mean dose: 5 mg/d for a period of more than 6 month), our data showed-similar to the collective of all patients-significant correlations (0.34<R<0.59) between DXR and the other methods. In contrast to pQCT (0.37<R<0.59) the study revealed a poor association between DXR- and DXA-parameters in the subgroup of patients without corticoid therapy; only the correlation between DXA-BMD of total femur and DXR-BMD achieved a significant level (R=0.38, p<0.05). The mean value of BMD measured by DXR decreased severity dependently from 0.59 g/cm(2) (Stage 1) to 0.46 g/cm(2) (Stage 5). Similar results were verified for the metacarpal index (DXR). The relative decrease of BMD between the highest and lowest score was 21% (p<0.05). Otherwise the reduction of bone mineral density using DXA revealed no significant results. CONCLUSION: The DXR-based BMD calculation can distinguish severity and progress of disease-related periarticular demineralization in contrast to those of DXA. In this context, DXA primarily measures the systemic (corticoid-induced) osteoporosis and pQCT partially estimates disease-related bone mineral density loss, whereas DXR can predominantly analyze and quantify the periarticular demineralization, which often shows a manifestation at an early stage of rheumatoid arthritis. Therefore DXR seems to be a diagnostic tool in the course of rheumatoid arthritis.

Absorptiometry, Photon↗

PubMed2004

Dyslexia: the possible benefit of multimodal integration of fMRI- and EEG-data.

Biological research about dyslexia has been conducted using various neuroimaging methods like functional Magnetic Resonance Imaging (fMRI) or Electroencephalography (EEG). Since language functions are characterized by both distributed network activities and speed of processing within milliseconds, high temporal as well as high spatial resolution of activation profiles are of interest: "where" can dyslexia specific activations be detected and "when" do language processes start to diverge between dyslexics and controls? Due to the network character of language processing, fMRI-constrained distributed source models based on EEG-data were computed for multimodal data integration. First single-case results show that this method could be a promising approach for the understanding of a repeatedly described experimental finding for dyslexia like that of an overactivation in inferior frontal language areas. Multimodal data analysis for the subjects presented here could probably demonstrate that inferior frontal overactivations are the consequence of a phonological deficit and could represent ongoing articulation processes used to solve phonologically challenging tasks.

Adolescent↗

PubMed2004

[Lymphadenitits caused by nontuberculous mycobacteria].

Infections caused by nontuberculous mycobacteria (NTM) commonly manifest as lymphadenitis in otherwise healthy children, as pneumonia in patients with chronic airway diseases, and as disseminated disease in patients with immunosuppression. The aim of this case report is to describe imaging findings (sonography, electrical impedance scanning, MRI) in children with NTM infection of the head and neck and to give some information about microbiologic findings and therapeutic options. In children presenting with enlarged neck masses and radiologically demonstrated nodal masses, the diagnosis of infections with NTM should be considered.

Child, Preschool↗