Income is associated with hippocampal/amygdala and education with cingulate cortex grey matter volume.

Income and education are both elements of a person's socioeconomic status, which is predictive of a broad range of life outcomes. The brain's gray matter volume (GMV) is influenced by socioeconomic status and mediators related to an unhealthy life style. We here investigated two independent general population samples comprising 2838 participants (all investigated with the same MRI-scanner) with regard to the association of indicators of the socioeconomic status and gray matter volume. Voxel-based morphometry without prior hypotheses revealed that years of education were positively associated with GMV in the anterior cingulate cortex and net-equivalent income with gray matter volume in the hippocampus/amygdala region. Analyses of possible mediators (alcohol, cigarettes, body mass index (BMI), stress) revealed that the relationship between income and GMV in the hippocampus/amygdala region was partly mediated by self-reported stressors, and the association of years of education with GMV in the anterior cingulate cortex by BMI. These results corrected for whole brain effects (and therefore not restricted to certain brain areas) do now offer possibilities for more detailed hypotheses-driven approaches.

Complexity of PEComas : Diagnostic approach, molecular background, clinical management.

Perivascular epithelioid cell neoplasms (PEComas) are a family of mesenchymal neoplasms with features of both melanotic and smooth muscle differentiation. PEComa morphology is highly variable and encompasses epithelioid to spindle cells often with clear cytoplasm and prominent nucleoli. Molecularly, most PEComas are defined by a loss of function of the TSC1/TSC2 complex. Additionally, a distinct small subset of PEComas harboring rearrangements of the TFE3 (Xp11) gene locus has been identified. By presenting a series of three case reports with distinct features, we demonstrate diagnostic pitfalls as well as the importance of molecular work-up of PEComas because of important therapeutic consequences.

[Complexity of PEComas : Diagnostic approach, molecular background, clinical management (German version)]. / Komplexität von PEComen : Diagnose, Molekulargenetik, klinisches Management.

Perivascular epithelioid cell neoplasms (PEComas) are a family of mesenchymal neoplasms with features of both melanotic and smooth muscle differentiation. PEComa morphology is highly variable and encompasses epithelioid to spindle cells often with clear cytoplasm and prominent nucleoli. Molecularly, most PEComas are defined by a loss of function of the TSC1/TSC2 complex. Additionally, a distinct small subset of PEComas harboring rearrangements of the TFE3 (Xp11) gene locus has been identified. By presenting a series of three case reports with distinct features, we demonstrate diagnostic pitfalls as well as the importance of molecular work-up of PEComas because of important therapeutic consequences.

Physically active life style is associated with increased grey matter brain volume in a medial parieto-frontal network.

To examine the association between the amount of sports activity performed during leisure time and gray matter volume (GMV) of the brain we investigated differences in GMV in a large cohort study of community-dwelling older adults. 967 individuals indicated their average weekly sports activity via a questionnaire, and underwent high resolution T1-weighted structural imaging of the brain. We used voxel based morphometry (CAT 12) in a region of interest approach for (1) comparing participants with higher versus lower sports activity (median split) and (2) calculating a linear regression on GMV and sports activity. We carefully corrected for other factors known to have an impact on GMV (sex, age, total brain volume, education, cigarettes and alcohol consumption, body mass index) and excluded pathology (history of psychiatric or neurological disease; visual inspection of brain scans). Those participants who spend more time performing sports activity per week (median split with > 1 h/week) showed higher GMV in the dorsomedial frontal lobe, the superior parietal lobe, and the precuneus/cuneus area. When splitting participants by their median (55.5 years) into two groups we found a stronger protective effect of sports against age related GMV decline for the older part of the cohort. Overall, a more active lifestyle was associated with increased GMV in areas associated with self-awareness and working memory. These cohort data support data on the protective role of sports activity for the GMV.

Subinternship in Radiology - A Practical Start to the Specialization?

Purpose: To identify factors influencing medical students to choose radiology in the four-month clinical elective in the final year of medical school following radiology subinternships. Materials and Methods: A subsample of medical students in a nationwide German online survey evaluated a subinternship in radiology (19 items). They were divided into four groups: Students who could imagine doing a clinical elective in radiology in the practical year based on their experiences during the subinternship ("yes, based on subinternship"), students who could not ("no, based on subinternship") and students who had made this decision prior to the subinternship ("yes, prior to subinternship" and "no, prior to subinternship"). Results: 94 medical students evaluated a radiology subinternship (54.4 % females). Based on their experiences during the subinternship, 54 students (57.4 %) intended to do a final year clinical elective in radiology, 39 of them (41.5 %) being encouraged by the subinternship. 40 (42.6 %) reported having a negative attitude towards a clinical elective in radiology, 16 of them (17.0 %) having made this decision based on their subinternship experience. Groups did not differ regarding gender (p = 0.396) and age (p = 0.853). Students motivated to do a final year clinical elective in radiology experienced excellent academic teaching (p = 0.001) and practical involvement (p = 0.003), achieved their learning goals more often (p = 0.001), were better integrated into the team (p = 0.001), and acquired more practical skills (p = 0.003). Overall satisfaction was higher in these groups (p = 0.001). Conclusion: Satisfaction with a radiology subinternship is crucial for motivating medical students to do a final year clinical elective in radiology. A structured subinternship and continuous mentoring should be targeted to keep students connected to radiology. Key Points: • Radiology subinternships influence further interest in the specialization.• The quality and structure of teaching critically influence student satisfaction.• Team integration and practical involvement positively affect the attitude towards a specialization. Citation Format: • Kasch R, Wirkner J, Hosten N et al. Subinternship in Radiology - A Practical Start to the Specialization? Fortschr Röntgenstr 2016; 188: 1024 - 1030.

Population-Based Imaging and Radiomics: Rationale and Perspective of the German National Cohort MRI Study.

UNLABELLED: The MRI study within the German National Cohort, a large-scale, population-based, longitudinal study in Germany, comprises comprehensive characterization and phenotyping of a total of 30 000 participants using 3-Tesla whole-body MR imaging. A multi-centric study design was established together with dedicated core facilities for e. g. managing incidental findings or providing quality assurance. As such, the study represents a unique opportunity to substantially impact imaging-based risk stratification leading to personalized and precision medicine. Supported by the developments in the field of computational science, the newly developing scientific field of radiomics has large potential for the future. In the present article we provide an overview on population-based imaging and Radiomics and conceptualize the rationale and design of the MRI study within the German National Cohort. KEY POINTS: • Population-based imaging and Radiomics constitute two emerging fields with great oppertunities and challenges for Radiology.• As part of the MRI-study of the NAKO approximately 30 000 subjects will undergo 3 Tesla whole-body MRI.• MR Imaging data is publicly accessable and will provide important insights into the natural history of disease processes and personalized risk profiles of the general population. Citation Format: • Schlett CL, Hendel T, Weckbach S et al. Population-Based Imaging and Radiomics: Rationale and Perspective of the German National Cohort MRI Study. Fortschr Röntgenstr 2016; 188: 652 - 661.

Advanced brain aging: relationship with epidemiologic and genetic risk factors, and overlap with Alzheimer disease atrophy patterns.

We systematically compared structural imaging patterns of advanced brain aging (ABA) in the general-population, herein defined as significant deviation from typical BA to those found in Alzheimer disease (AD). The hypothesis that ABA would show different patterns of structural change compared with those found in AD was tested via advanced pattern analysis methods. In particular, magnetic resonance images of 2705 participants from the Study of Health in Pomerania (aged 20-90 years) were analyzed using an index that captures aging atrophy patterns (Spatial Pattern of Atrophy for Recognition of BA (SPARE-BA)), and an index previously shown to capture atrophy patterns found in clinical AD (Spatial Patterns of Abnormality for Recognition of Early Alzheimer's Disease (SPARE-AD)). We studied the association between these indices and risk factors, including an AD polygenic risk score. Finally, we compared the ABA-associated atrophy with typical AD-like patterns. We observed that SPARE-BA had significant association with: smoking (P<0.05), anti-hypertensive (P<0.05), anti-diabetic drug use (men P<0.05, women P=0.06) and waist circumference for the male cohort (P<0.05), after adjusting for age. Subjects with ABA had spatially extensive gray matter loss in the frontal, parietal and temporal lobes (false-discovery-rate-corrected q<0.001). ABA patterns of atrophy were partially overlapping with, but notably deviating from those typically found in AD. Subjects with ABA had higher SPARE-AD values; largely due to the partial spatial overlap of associated patterns in temporal regions. The AD polygenic risk score was significantly associated with SPARE-AD but not with SPARE-BA. Our findings suggest that ABA is likely characterized by pathophysiologic mechanisms that are distinct from, or only partially overlapping with those of AD.

Comparing perfusion CT evaluation algorithms for predicting outcome after endovascular treatment in anterior circulation ischaemic stroke.

AIM: To analyse perfusion CT (PCT) evaluation algorithms for their predictive value for outcome after endovascular therapy (ET) in acute ischaemic stroke. MATERIALS AND METHODS: Twenty-six patients were prospectively enrolled to undergo endovascular therapy for moderate to severe [National Institute of Health Stroke Scale (NIHSS) score of ≥5] anterior circulation stroke ≤6 h of onset. PCT datasets were evaluated according to three algorithms: visual mismatch estimate (VME), Alberta Stroke Programme Early CT Score (ASPECTS) perfusion, and quantitative perfusion ratios (QPRs: RCBF, RCBV) of cerebral blood flow (CBF) and volume (CBV). Results were correlated with outcome measures [NIHSS score at discharge, NIHSS score change until discharge (ΔNIHSSA/D), mRS at 90 days (mRS90d)] and compared with a matched control group. RESULTS: Recanalization was achieved in 73%, median NIHSS score decreased from 14 to 5 at discharge. The treatment and control group did not differ by VME and ASPECTS perfusion, nor did VME correlate with any of the three outcome measures. ASPECTS perfusion was not predictive of any outcome measure in the ET group. RCBF and RCBV were associated with ΔNIHSSA/D in controls and, inversely, the ET group, but not with mRS90d. Receiver operating characteristic (ROC) analysis of RCBF (and RCBV) showed a positive predictive and negative predictive value of 87% (78%) and 74% (73%), respectively, for discriminating major neurological improvement (ΔNIHSSA/D <7 versus ≥7). CONCLUSIONS: Implementation of QPRs for CBF and CBV are superior to clinically used VME and ASPECTS perfusion evaluation methods for predicting early outcome after ET for anterior circulation stroke.

Feasibility of gadoxetate disodium-enhanced MR cholangiography in chronic cholestatic biliary disease.

AIM: To investigate the feasibility of gadoxetate disodium-enhanced magnetic resonance (MR) cholangiography in chronic obstructive cholestatic biliary disease in the clinical setting. MATERIALS AND METHODS: Twenty-three patients with dilated bile duct trees and ten volunteers underwent gadoxetate disodium-enhanced liver MR cholangiography and were enrolled in the present retrospective study. Gadoxetate disodium was given in a standardized manner as a bolus injection at a dose of 0.25 mmol/kg of body weight (0.1 ml/kg). Region of interest-based measurement of mean enhancement of the dilated bile ducts was performed in series before gadoxetate disodium administration and during hepatobiliary phases. RESULTS: Direct comparison of mean bile duct enhancement during hepatobiliary phases in the clinical imaging window between healthy volunteers [4.7 ± 2.2 arbitrary units (au)] and patients with dilated bile ducts (0.1 ± 0.3 au) revealed significantly lower or absent enhancement in dilated bile ducts (p = 0.001). CONCLUSION: Standard clinical gadoxetate disodium-enhanced MR cholangiography is not a reliable technique for the evaluation of the biliary trees, because of altered biliary gadoxetate disodium elimination in patients with chronic obstructive biliary diseases.

MR microscopy of the human finger and correlation with histology--a proof-of-principle study.

Magnetic resonance imaging (MRI) with small surface coils is a well established method for the diagnostic evaluation of finger masses. Until now, histological examination has been required to reliably assess tumor extent and infiltration of surrounding structures. Ultra-high-field MR microscopy (MRM) allows evaluation of anatomical structures and pathologies with submillimeter resolution. This study describes the diagnostic prospects and potential of MRM based on the ex-vivo examination of different finger pathologies. Ten human digits were examined by ex-vivo MRM at 7.1 Tesla (ClinScan, Bruker BioScan) using a T2-weighted turbo spin echo (TSE) sequence. Imaging parameters were: TE 48 ms; TR 8370 ms; slice thickness 700 µm; matrix size 1024 × 1024 pixels; FOV 37 × 37 mm; in-plane resolution 36 × 36 µm/voxel. Afterwards specimens were examined histologically. Histology and MRM were correlated. MRM allowed evaluation of the anatomy of the nail, the tendon insertions, the distal interphalangeal joint, and the neurovascular bundles. Finger abnormalities evaluated by MRM included osteomyelitis and metastatic disease. Subsequent histological examination confirmed MRM findings regarding origin, internal makeup, and extent of the structures visualized. This study demonstrates the potential of MRM for imaging small anatomical structures and pathologies of the human finger. Our ex-vivo findings correlate strongly with histology, suggesting that MRM may gain a central role in assessing anatomical structures and pathology in terms of morphology, extent, and infiltration of surrounding structures. Therefore, with increasing availability, MRM is expected to become an essential tool not only in experimental studies but also for daily routine.

[Endovascular treatment of acute ischemic stroke under conscious sedation compared to general anesthesia - safety, feasibility and clinical and radiological outcome]. / Endovaskuläre Therapie des akut ischämischen Schlaganfalls unter Analgosedierung im Vergleich zur Intubationsnarkose - Durchführbarkeit, periprozedurale Sicherheit, klinisches und radiologisches Outcome.

PURPOSE: Vessel recanalization is an important predictor of clinical outcome in the treatment of acute ischemic stroke. Endovascular therapies are used with increasing frequency. There is no general agreement on the policy of anesthesia during endovascular therapy, ranging from general anesthesia (GA) to local anesthesia at the puncture site with conscious sedation (CS) as needed. The aim of the study was to evaluate the safety and feasibility and radiological and clinical outcome of endovascular stroke therapy under CS. MATERIALS AND METHODS: We retrospectively included all patients with acute ischemic stroke who were treated with endovascular therapy over a five-year period. Data was evaluated with respect to type of sedation, conversion from CS to GA, recanalization rate, infarct volume and peri- and post-procedural complications. RESULTS: There was a technical failure in 7 patients. Of the remaining 124 patients (mean age 68.8 ± 14.6 years), 65 were female (52 %). The site of occlusion was located in the anterior circulation in 94 patients (76 %) and in the posterior circulation in 30 cases (24 %). 105 patients (85 %) were treated under CS and 16 cases (13 %) primarily under GA. In 3 cases (2 %) peri-procedural conversion to GA was necessary. Primary intra-arterial thrombolysis, mechanical recanalization only, and combination therapy were performed in 60 (48 %), 27 (22 %) and 37 (30 %) patients, respectively. There were no significant differences for recanalization rate and complications between GA and CS. The mean procedure time was significantly shorter in patients treated under CS (p < 0.01). CONCLUSION: Endovascular stroke therapy with CS is feasible, can be performed safely and is faster than with GA.

Population imaging as valuable tool for personalized medicine.

Personalized medicine is commonly regarded as an extension of genomic medicine. However, a personalized treatment should not [corrected] be based solely on the presence or absence of genetic factors. Complex imaging methods supplement the diagnostic picture of an individual patient. Comprehensive imaging in population-based settings provides information on reference intervals, the predictive value of subclinical findings, and the complex interrelationships among risk factors, subclinical imaging phenotypes, and diseases.

[Laser ablation. Do we still need it?]. / Laserablation. Brauchen wir sie noch?

Laser ablation (LA) is momentarily the only invasive ablation procedure besides radiofrequency ablation (RFA) which can be performed entirely under magnetic resonance imaging (MRI) guidance. The long-term outcome and morbidity profiles are broadly identical for both modalities, excluding the RFA-specific prevalence for skin burns. The technical and logistic disadvantages of LA have been overcome since the introduction of miniaturized two-component applicators. The main advantage of LA is its superior MRI compatibility. Interference-free imaging during LA allows MR thermometric real-time therapy control without the need for RF filters. High-resolution thermometry in the target zone only makes sense without the extinction artifact of a metal probe and this condition is met only by the glass fibers of LA. An independent therapy monitoring is crucial in modern scenarios of oncologic quality management.

[Diffusion-weighted MRI - how many B-values are necessary?]. / Diffusionsgewichtete MRT - wie viele Diffusionsfaktoren sind notwendig?

PURPOSE: Diffusion-weighted imaging (DWI) has become an important component in modern stroke imaging. This MR technique detects diffusion abnormalities, which can be quantified by computing apparent diffusion coefficient (ADC) maps. ADC values are typically calculated from a set of MR images obtained with varying degrees of diffusion weighting (b-values) using nonlinear regression. However, there is no agreement concerning the number of images needed for ADC calculation. The aim of our study was to determine how many b-values are necessary to reliably calculate ADC maps. MATERIALS AND METHODS: In 100 consecutive patients with clinical signs of acute ischemic stroke, 6 identically oriented and centered diffusion data sets with different b-values were acquired. ROI analysis was performed for DWI-positive lesions, normal-appearing gray and white matter, CSF, and background noise. ADC values for each ROI were calculated using a nonlinear regression model. Additionally, the CNR and SNR were calculated for each ROI. RESULTS: Acquisition time was 0:39 min for 2 b-values and up to 2:49 min for a sequence with 7 b-values. The mean ADC (× 10(-3) mm2/s) for ischemic lesions was 58.29, 58.47, 57.83, 57.81, 57.58 and 54.51 using 2, 3, 4, 5, 6, and 7 b-values. Ischemic lesions had significantly different mean ADC values only for high b-values (b = 2000 s/mm2). CONCLUSION: ADC values can be reliably calculated using 2 b-values. Radiologists may use the more time-efficient 2-point method for reliably estimating ADC values and detecting ischemic lesions in the daily clinical routine.

[Diagnosing neurovascular compression syndromes]. / Diagnostik neurovaskulärer Kompressionssyndrome.

PURPOSE: Neurovascular compression syndromes are diseases caused by abnormal contact between a vessel loop and the root exit/entry zone of a cranial nerve. Compression can cause paroxysmal attacks of abnormal motor or sensory phenomena in the affected nerve. MATERIALS AND METHODS: Review based on a selective analysis of the literature. RESULTS: Neurovascular compression syndromes include well-established entities such as trigeminal neuralgia, facial hemispasm, vestibular paroxysmia and glossopharyngeus neuralgia but also cranial nerve disorders caused by compression due to an aneurysm, e. g., oculomotor nerve paresis caused by an aneurysm of the posterior communicating branch. An overview of neurovascular compression syndromes is given, outlining diagnostic procedures and the morphological imaging features of each syndrome as well as the changes seen after treatment are described. CONCLUSION: Neurovascular compression syndromes are complex diseases. MR imaging plays an important role in the diagnostic workup of these diseases.

Neurogenic heterotopic ossification: epidemiology and morphology on conventional radiographs in an early neurological rehabilitation population.

OBJECTIVE: To retrospectively evaluate neurogenic heterotopic ossification in an early neurological rehabilitation population (phases B and C) with respect to epidemiology and morphology on conventional radiographs. MATERIALS AND METHODS: Over a 4-year period, 1,463 patients treated at a clinic for early neurological rehabilitation were evaluated for clinical symptoms of neurogenic heterotopic ossification. In case of clinical suspicion, plain radiographs of the expected sites were obtained. If heterotopic ossification was detected, the initial and subsequent radiographs were retrospectively analyzed for sites, size, and morphology. Immature lesions were categorized as small (<10 mm) or large (10-100 mm). RESULTS: The prevalence rate of neurogenic heterotopic ossification was 2.05%. The condition was most common in young male adults. The hip was the most common site accounting for more than half of the cases. Two or more ossifications were seen in 56.7% of the affected patients with approximately two-thirds showing bilateral symmetric involvement of corresponding joint regions. The size of ossifications strongly varied interindividually. Small immature lesions demonstrated less progression in size than large lesions during maturation (P < 0.05). CONCLUSION: Standard radiographs, as a fast and inexpensive technique, allow the expected size progression of heterotopic ossifications during maturation to be estimated, which is relevant in terms of therapeutic decisions, patient mobilization, and neurological rehabilitation.

[MR microscopy of the human eye]. / MR-Mikroskopie des humanen Auges.

Ultra-high-field MR microscopy is a novel, non-invasive imaging technique to explore the strcutures of the human eye without optical distorsions. This review aims to provide an insight into the technique of the method. The normal MR microscopic anatomy of the human eye with correlations to histology is demonstrated. The use of MR microscopy in ther experimental ophthalmological setting is discussed.

[Medical and legal aspects of teleradiology in Germany]. / Medizinische und rechtliche Aspekte der Teleradiologie in Deutschland.

In teleradiology, imaging data are transferred over a distance. This service is provided for the purpose of consulting or teleradiological reading in the narrower sense. Once a justification has been proposed in the latter, the examination is performed under the responsibility of a radiologist who is not present on site. The need for teleradiology services often derives from sparsely populated areas, a shortage of doctors, or the need for cost-efficient provision of radiological examinations. The providers and recipients of teleradiology services enter into an agreement specifying conditions for data transfer. The German ionizing radiation (medical exposure) regulations demand that the teleradiologist holds radiation protection qualifications and is able to reach the examination site within 45 - 60 minutes. In Germany, teleradiology services are still limited to nights, weekends, and vacations, although the German regulations allow an expansion under certain circumstances. Efforts to fundamentally change radiology in favor of teleradiology are putting the status of a radiological medical act as well as current teaching models at risk, thereby indirectly sustaining physician shortage. Transnational teleradiology services offer the possibility of cost reduction, taking advantage of out-of-hour reading and wage fluctuation. At the same time, such services are associated with deficits in quality and availability of personnel as well as the quality of medical services. In the long-term teleradiology concepts will fundamentally change radiology. Smaller radiology units will concentrate on daily business and fast reporting. Larger units also providing academic teaching can use teleradiology networks to offer specialized readings.