SPECT/CT and pulmonary embolism

Acute pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/P) scintigraphy or pulmonary CT angiography (CTPA). In recent years both techniques have improved. Many nuclear medicine centres have adopted the single photon emission CT (SPECT) technique as opposed to the planar technique for diagnosing PE. SPECT has been shown to have fewer indeterminate results and a higher diagnostic value. The latest improvement is the combination of a low-dose CT scan with a V/P SPECT scan in a hybrid tomograph. In a study comparing CTPA, planar scintigraphy and SPECT alone, SPECT/CT had the best diagnostic accuracy for PE. In addition, recent developments in the CTPA technique have made it possible to image the pulmonary arteries of the lungs in one breath-hold. This development is based on the change from a single-detector to multidetector CT technology with an increase in volume coverage per rotation and faster rotation. Furthermore, the dual energy CT technique is a promising modality that can provide functional imaging in combination with anatomical information. Newer high-end CT scanners and SPECT systems are able to visualize smaller subsegmental emboli. However, consensus is lacking regarding the clinical impact and treatment. In the present review, SPECT and SPECT in combination with low-dose CT, CTPA and dual energy CT are discussed in the context of diagnosing PE

<i>In Vivo</i> phenotyping of tumor metabolism in a canine cancer patient with simultaneous ¹⁸F-FDG-PET and hyperpolarized ¹³C-Pyruvate magnetic resonance spectroscopic imaging (hyperPET):mismatch demonstrates that FDG may not always reflect the Warburg effect

In this communication the mismatch between simultaneous 18F-FDG-PET and a 13C-lactate imaging (hyperPET) in a biopsy verified squamous cell carcinoma in the right tonsil of a canine cancer patient is shown. The results demonstrate that 18F-FDG-PET may not always reflect the Warburg effect in all tumors

Subcortical volumes across the lifespan: Data from 18,605 healthy individuals aged 3–90 years

Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resources of the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Consortium to examine age‐related trajectories inferred from cross‐sectional measures of the ventricles, the basal ganglia (caudate, putamen, pallidum, and nucleus accumbens), the thalamus, hippocampus and amygdala using magnetic resonance imaging data obtained from 18,605 individuals aged 3–90 years. All subcortical structure volumes were at their maximum value early in life. The volume of the basal ganglia showed a monotonic negative association with age thereafter; there was no significant association between age and the volumes of the thalamus, amygdala and the hippocampus (with some degree of decline in thalamus) until the sixth decade of life after which they also showed a steep negative association with age. The lateral ventricles showed continuous enlargement throughout the lifespan. Age was positively associated with inter‐individual variability in the hippocampus and amygdala and the lateral ventricles. These results were robust to potential confounders and could be used to examine the functional significance of deviations from typical age‐related morphometric patterns

Cortical thickness across the lifespan: Data from 17,075 healthy individuals aged 3-90 years

Delineating the association of age and cortical thickness in healthy individuals is critical given the association of cortical thickness with cognition and behavior. Previous research has shown that robust estimates of the association between age and brain morphometry require large‐scale studies. In response, we used cross‐sectional data from 17,075 individuals aged 3–90 years from the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Consortium to infer age‐related changes in cortical thickness. We used fractional polynomial (FP) regression to quantify the association between age and cortical thickness, and we computed normalized growth centiles using the parametric Lambda, Mu, and Sigma method. Interindividual variability was estimated using meta‐analysis and one‐way analysis of variance. For most regions, their highest cortical thickness value was observed in childhood. Age and cortical thickness showed a negative association; the slope was steeper up to the third decade of life and more gradual thereafter; notable exceptions to this general pattern were entorhinal, temporopolar, and anterior cingulate cortices. Interindividual variability was largest in temporal and frontal regions across the lifespan. Age and its FP combinations explained up to 59% variance in cortical thickness. These results may form the basis of further investigation on normative deviation in cortical thickness and its significance for behavioral and cognitive outcomes

Quality Controlled Continuously Formed NCF-Preforms

Environmental and economic requirements call for lightweight aircraft design and for cost efficient manufacturing processes. Lightweight design can be reached by the use of composite materials, which have low specific weight. Carbon fiber reinforced polymers (CFRP) are especially suited for air frame production. Full exploitation of the composite’s potential requires a specialized design. One aspect of such a design is a fiber orientation that accounts for the dimensioning load case. Regarding cost efficient manufacturing processes, resin transfer moulding (RTM) using low-cost non-crimp fabrics (NCF) is a very promising option. The preforming process is crucial for optimal and reproducible mechanical properties. Using a fuselage frame as an example, a novel approach of roll forming NCF into a complex curved profile is presented. The patented continuously working principle allows for accurate fiber orientation along the preform and offers a fast and flexible alternative to processes based on solid preform-tools. Automation not only provides cost-efficient processes but also leads to reproducible accuracies. Accompanied by an online quality assurance system that consistently measures the fiber orientation of each layer, the process meets high quality requirements. Inspecting all layers of a stacking enables a complete quality check in the preforming process

Adaptive, Tolerant and Efficient Composite Structures: Continuous Preforming with Variable Web Height Adjustment

Preforming is required for complex shaped profiles manufactured in liquid composite moulding (LCM) processes. The stacking is made of dry fiber fabrics, which are infiltrated in a later process step. The complete stacking is called preform. The fixing of the textile layers can be realised through stitching or binder technology. The main disadvantage is the immense rate of manual work within the preform process. In consequence, the manufacturing is costly in terms of time and high effort for quality control. Automated preforming can reduce the costs by increasing the output and production rate while minimising waste. Preform profiles with variable outlines and non-extrudable sections are of particular interest for the aviation and automotive industry. The DLR Institute of Composite Structures and Adaptive Systems has developed an innovative device to overcome the previous limitations and to fulfil the industrial demands

Entwicklung einer Anlage zur seriennahen Fertigung von Doppel-T-Profilen mit höhenveränderlicher Außenkontur aus trockenen Faserhalbzeugen

Because of more CFRP-structures upcoming in aircrafts to reduce the weight, the fuel needs and the exhaust emissions there will be more requirements to the manufacturing processes. One possibility to reduce the costs of these processes is to use preforms because of expensive storage costs of prepregs and non-automated manual manufacturing processes. For the production of double-T-profiles with a variable height for integration in vertical tail planes in aircrafts of Airbus, there are automated manufacturing processes and systems needed. The goal of this thesis is to develop a new manufacturing plant, based on a realized prototype plant, to produce profiles with a new specification and for approximately series production