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Sample records for hochaufloesende computertomographie hr-ct

  1. A novel method for 4D cone-beam computer-tomography reconstruction

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Park, Justin C.; Chen, Yunmei; Lan, Guanghui; Lu, Bo

    2015-03-01

    Image quality of Four Dimensional Cone-Beam Computer-Tomography (4DCBCT) is severely impaired by highly insufficient amount of projection data available for each phase. Therefore, making good use of limited projection data is crucial to solve this problem. Noticing that usually only a portion of the images is affected by motion, we separate the moving part (different between phases) of the images from the static part (identical among all phases) with the help of prior image reconstructed using all projection data. Then we update the moving part and the static part of images alternatively through solving minimization problems based on a global (use full projection data) and several local (use projection data for respective phase) linear systems. In the other word, we rebuild a large over-determined linear system for static part from the original under-determined systems and we reduce the number of unknowns in the original system for each phase as well. As a result, image quality for both static part and moving part are greatly improved and reliable 4D CBCT images are then reconstructed.

  2. [Post-traumatic hydrocephalus--result of repeated abuse of a young child].

    PubMed

    Tributsch, W; Ambach, E; Rabl, W

    1990-01-01

    Serious physical and psychic abuse of children is a much discussed theme in forensic, juridical and sociological literature. This paper deals with the pitiable case of a meanwhile four years old infant having been battered by his stepmother. At the age of two years the boy was unconscious admitted to the hospital. Computertomography of the brain did not show any pathological findings. Because of multiple effusions of blood of variable age located at the child's body the stepmother was noticed and accused of assault and battery, but the trial ended in acquittal. Two years later the boy suffered from serious neurological symptoms and computertomography showed high-pathological alterations such as hydrocephalus, parietooccipital hygroma and a damage of the brain.

  3. [Post-traumatic hematoma simulating a left-sided adrenal gland tumor].

    PubMed

    Will, C H; Hoeppener, H J; Beutler, W

    1990-01-01

    Typical signs of posttraumatic adrenal gland haematoma in computer-tomography are, besides an enlargement of the adrenal gland, a stripy infiltration of surrounding tissue and a thickening of the homolateral crus of the diaphragma, located primarily in the right adrenal gland. We report a case of an isolated enlargement of the left adrenal gland with normal surrounding tissue, which histologically proved to be a posttraumatic hematoma within the adrenal gland medulla.

  4. Forensic veterinary radiology: ballistic-radiological 3D computertomographic reconstruction of an illegal lynx shooting in Switzerland.

    PubMed

    Thali, Michael J; Kneubuehl, Beat P; Bolliger, Stephan A; Christe, Andreas; Koenigsdorfer, Urs; Ozdoba, Christoph; Spielvogel, Elke; Dirnhofer, Richard

    2007-08-24

    The lynx, which was reintroduced to Switzerland after being exterminated at the beginning of the 20th century, is protected by Swiss law. However, poaching occurs from time to time, which makes criminal investigations necessary. In the presented case, an illegally shot lynx was examined by conventional plane radiography and three-dimensional multislice computertomography (3D MSCT), of which the latter yielded superior results with respect to documentation and reconstruction of the inflicted gunshot wounds. We believe that 3D MSCT, already described in human forensic-pathological cases, is also a suitable and promising new technique for veterinary pathology.

  5. Statistical model for the correlation length of snow derived from SnowMicroPen measurements.

    NASA Astrophysics Data System (ADS)

    Proksch, M.; Loewe, H.; Schneebeli, M.

    2012-12-01

    The SnowMicroPen (SMP) allows to retrieve mechanical parameters from the snowpack. However, remote sensing applications rely on structural parameters of snow such as the correlation length. Due to the complexity of the physical connection between structural and mechanical parameters we derived a statistical model for the correlation length from SMP measurements. To this end we have analyzed snow samples of many different snow classes and densities by micro computer-tomography (CT) and SMP. We correlated the SMP-derived structural element length with the CT-derived correlation length and validated the model using field data taken during the NoSREx - III campaign in Sodankylä, Finland. Further, we employ the statistical model to estimate the specific surface area from combined SMP and density measurement from natural snow profiles. We compare this SSA estimate to independent SSA measurements by near-infrared photography and discuss potential and limitation of the method.

  6. Advanced imaging of the macrostructure and microstructure of bone

    NASA Technical Reports Server (NTRS)

    Genant, H. K.; Gordon, C.; Jiang, Y.; Link, T. M.; Hans, D.; Majumdar, S.; Lang, T. F.

    2000-01-01

    Noninvasive and/or nondestructive techniques are capable of providing more macro- or microstructural information about bone than standard bone densitometry. Although the latter provides important information about osteoporotic fracture risk, numerous studies indicate that bone strength is only partially explained by bone mineral density. Quantitative assessment of macro- and microstructural features may improve our ability to estimate bone strength. The methods available for quantitatively assessing macrostructure include (besides conventional radiographs) quantitative computed tomography (QCT) and volumetric quantitative computed tomography (vQCT). Methods for assessing microstructure of trabecular bone noninvasively and/or nondestructively include high-resolution computed tomography (hrCT), micro-computed tomography (muCT), high-resolution magnetic resonance (hrMR), and micromagnetic resonance (muMR). vQCT, hrCT and hrMR are generally applicable in vivo; muCT and muMR are principally applicable in vitro. Although considerable progress has been made in the noninvasive and/or nondestructive imaging of the macro- and microstructure of bone, considerable challenges and dilemmas remain. From a technical perspective, the balance between spatial resolution versus sampling size, or between signal-to-noise versus radiation dose or acquisition time, needs further consideration, as do the trade-offs between the complexity and expense of equipment and the availability and accessibility of the methods. The relative merits of in vitro imaging and its ultrahigh resolution but invasiveness versus those of in vivo imaging and its modest resolution but noninvasiveness also deserve careful attention. From a clinical perspective, the challenges for bone imaging include balancing the relative advantages of simple bone densitometry against the more complex architectural features of bone or, similarly, the deeper research requirements against the broader clinical needs. The

  7. The effect of comorbidities on COPD assessment: a pilot study

    PubMed Central

    Weinreich, Ulla Møller; Thomsen, Lars Pilegaard; Bielaska, Barbara; Jensen, Vania Helbo; Vuust, Morten; Rees, Stephen Edward

    2015-01-01

    Introduction Patients with chronic obstructive pulmonary disease (COPD) frequently suffer from comorbidities. COPD severity may be evaluated by the Global initiative for chronic Obstructive Lung Disease (GOLD) combined risk assessment score (GOLD score). Spirometry, body plethysmography, diffusing capacity of the lung for carbon monoxide (DLCO), and high-resolution computed tomography (HR-CT) measure lung function and elucidate pulmonary pathology. This study assesses associations between GOLD score and measurements of lung function in COPD patients with and without (≤1) comorbidities. It evaluates whether the presence of comorbidities influences evaluation by GOLD score of COPD severity, and questions whether GOLD score describes morbidity rather than COPD severity. Methods In this prospective study, 106 patients with stable COPD were included. Patients treated for lung cancer were excluded. Demographics, oxygen saturation (SpO2), modified Medical Research Council Dyspnea Scale, COPD exacerbations, and comorbidities were recorded. Body plethysmography and DLCO were measured, and HR-CT performed and evaluated for emphysema and airways disease. COPD severity was stratified by the GOLD score. Correlation analyses: 1) GOLD score, 2) emphysema grade, and 3) airways disease and lung function parameters, described by: forced expiratory volume in the first second in percent of expected value (FEV1%), inspiratory capacity (IC%), total lung volume (TLC%), IC/TLC, and SpO2. Correlation analyses between subgroups and hierarchical cluster analysis were performed. Results Significant associations were found between GOLD score and both emphysema grade (correlation coefficients [cc]: −0.2, P=0.03) and lung function parameters (cc: −0.5 to −0.7, P-values all <0.001) weakened in patients with >1 comorbidity (cc: −0.4 to −0.5, P-values all 0.001). Significant differences between subgroups were found in GOLD score and both FEV1% (cc: −0.2, P=0.02) and IC/TLC (cc: −0

  8. Bone fragility and imaging techniques

    PubMed Central

    D’Elia, Giovanni; Caracchini, Giuseppe; Cavalli, Loredana; Innocenti, Paolo

    2009-01-01

    Bone fragility is a silent condition that increases bone fracture risk, enhanced by low bone mass and microarchitecture deterioration of bone tissue that lead to osteoporosis. Fragility fractures are the major clinical manifestation of osteoporosis. A large body of epidemiological data indicates that the current standard for predicting fragility fracture risk is an areal BMD (aBMD) measurement by DXA. Although mineral density measurements assess the quantity of bone, the quality of the tissue is an important predictor of fragility. Thus, bone strength is explained not only by BMD but also by macrostructural and microstructural characteristics of bone tissue. Imaging diagnostics, through the use of X-rays, DXA, Ultrasonography, CT and MR, provides methods for diagnosis and characterization of fractures, and semi- and quantitative methods for assessment of bone consistency and strength, that become precious for bone fragility clinical management if they are integrated by clinical risk factors. The last employment of sophisticated non-invasively imaging techniques in clinical research as high-resolution CT (hrCT), microCT (μ-CT), high-resolution MR (hrMR) and, microRM (μRM), combined with finite element analysis methods, open to new challenges in a better bone strength assessment to enhance the comprehension of biomechanical parameters and the prediction of fragility fractures. PMID:22461252

  9. FELIX: a volumetric 3D laser display

    NASA Astrophysics Data System (ADS)

    Bahr, Detlef; Langhans, Knut; Gerken, Martin; Vogt, Carsten; Bezecny, Daniel; Homann, Dennis

    1996-03-01

    In this paper, an innovative approach of a true 3D image presentation in a space filling, volumetric laser display will be described. The introduced prototype system is based on a moving target screen that sweeps the display volume. Net result is the optical equivalent of a 3D array of image points illuminated to form a model of the object which occupies a physical space. Wireframe graphics are presented within the display volume which a group of people can walk around and examine simultaneously from nearly any orientation and without any visual aids. Further to the detailed vector scanning mode, a raster scanned system and a combination of both techniques are under development. The volumetric 3D laser display technology for true reproduction of spatial images can tremendously improve the viewers ability to interpret data and to reliably determine distance, shape and orientation. Possible applications for this development range from air traffic control, where moving blips of light represent individual aircrafts in a true to scale projected airspace of an airport, to various medical applications (e.g. electrocardiography, computer-tomography), to entertainment and education visualization as well as imaging in the field of engineering and Computer Aided Design.

  10. Optimising μCT imaging of the middle and inner cat ear.

    PubMed

    Seifert, H; Röher, U; Staszyk, C; Angrisani, N; Dziuba, D; Meyer-Lindenberg, A

    2012-04-01

    This study's aim was to determine the optimal scan parameters for imaging the middle and inner ear of the cat with micro-computertomography (μCT). Besides, the study set out to assess whether adequate image quality can be obtained to use μCT in diagnostics and research on cat ears. For optimisation, μCT imaging of two cat skull preparations was performed using 36 different scanning protocols. The μCT-scans were evaluated by four experienced experts with regard to the image quality and detail detectability. By compiling a ranking of the results, the best possible scan parameters could be determined. From a third cat's skull, a μCT-scan, using these optimised scan parameters, and a comparative clinical CT-scan were acquired. Afterwards, histological specimens of the ears were produced which were compared to the μCT-images. The comparison shows that the osseous structures are depicted in detail. Although soft tissues cannot be differentiated, the osseous structures serve as valuable spatial orientation of relevant nerves and muscles. Clinical CT can depict many anatomical structures which can also be seen on μCT-images, but these appear a lot less sharp and also less detailed than with μCT.

  11. A coin-like peripheral small cell lung carcinoma associated with acute paraneoplastic axonal Guillain-Barre-like syndrome.

    PubMed

    Jung, Ioan; Gurzu, Simona; Balasa, Rodica; Motataianu, Anca; Contac, Anca Otilia; Halmaciu, Ioana; Popescu, Septimiu; Simu, Iunius

    2015-06-01

    A 65-year-old previously healthy male heavy smoker was hospitalized with a 2-week history of progressive muscle weakness in the lower and upper extremities. After 10 days of hospitalization, urinary sphincter incompetence and fecal incontinence were added and tetraparesis was established. The computer-tomography scan examination revealed a massive right hydrothorax and multifocal solid acinar structures with peripheral localization in the left lung, which suggested pulmonary cancer. Bone marrow metastases were also suspected. Based on the examination results, the final diagnosis was acute paraneoplastic axonal Guillain-Barre-like syndrome. The patient died 3 weeks after hospitalization. At autopsy, bronchopneumonia and a right hydrothorax were confirmed. Several 4 to 5-mm-sized round peripherally located white nodules were identified in the left lung, without any central tumor mass. Under microscope, a coin-shaped peripheral/subpleural small cell carcinoma was diagnosed, with generalized bone metastases. A huge thrombus in the abdominal aorta and acute pancreatitis was also seen at autopsy. This case highlights the difficulty of diagnosis of lung carcinomas and the necessity of a complex differential diagnosis of severe progressive ascending neuropathies. This is the 6th reported case of small cell lung cancer-associated acute Guillain-Barre-like syndrome and the first report about an association with a coin-like peripheral pattern. PMID:26039124

  12. Structural analysis of paintings based on brush strokes

    NASA Astrophysics Data System (ADS)

    Sablatnig, Robert; Kammerer, Paul; Zolda, Ernestine

    1998-05-01

    The origin of works of art can often not be attributed to a certain artist. Likewise it is difficult to say whether paintings or drawings are originals or forgeries. In various fields of art new technical methods are used to examine the age, the state of preservation and the origin of the materials used. For the examination of paintings, radiological methods like X-ray and infra-red diagnosis, digital radiography, computer-tomography, etc. and color analyzes are employed to authenticate art. But all these methods do not relate certain characteristics in art work to a specific artist -- the artist's personal style. In order to study this personal style of a painter, experts in art history and image processing try to examine the 'structural signature' based on brush strokes within paintings, in particular in portrait miniatures. A computer-aided classification and recognition system for portrait miniatures is developed, which enables a semi- automatic classification and forgery detection based on content, color, and brush strokes. A hierarchically structured classification scheme is introduced which separates the classification into three different levels of information: color, shape of region, and structure of brush strokes.

  13. Echtzeit-Ultraschallsimulation auf Grafik-Prozessoren mit CUDA

    NASA Astrophysics Data System (ADS)

    Reichl, Tobias; Passenger, Josh; Acosta, Oscar; Salvado, Olivier

    Trotz der zunehmenden Verbreitung jüngerer bildgebender Verfahren bleibt medizinischer Ultraschall (US) weiterhin ein wichtiges Hilfsmittel bei chirurgischen Eingriffen und der klinischen Diagnose. Viele US-gestützte medizinische Prozeduren erfordern allerdings ausgiebiges Training, so dass es wünschenswert ist, eine realistische Simulation von US-Bildern zur Verfügung zu stellen. Im Gegensatz zu früheren Ansätzen simulieren wir solche Bilder auf der "Graphics Processing Unit“. Wir erweitern hierzu eine Methode, die von Wein et al. für die Abschätzung von US-Reflexionen aus Daten der Computertomographie (CT) vorgeschlagen wurde, zu einer leichter zu berechnenden Form. Zusätzlich schätzen wir die US-Absorption aus den CT-Daten ab. Mit Hilfe von NVIDIAs "Compute Unified Device Architecture“ (CUDA) simulieren wir Reflexion, Verschattung, Rauschen und radiale Unschärfe, ausgehend von unbearbeiteten CT-Daten in Echtzeit und ohne Vorausberechnung.

  14. Recent progress in bone imaging for osteoporosis research.

    PubMed

    Ito, Masako

    2011-03-01

    Advances in bone imaging techniques have provided tools for analyzing bone structure at the macro-, micro- and nano-level. Quantitative assessment of macrostructure can be achieved using dual X-ray absorptiometry (DXA) and quantitative computed tomography (QCT), particularly volumetric quantitative CT (vQCT). In vivo quantitative techniques for assessing the microstructure of trabecular bone non-invasively and non-destructively include high-resolution CT (HR-CT) and high-resolution magnetic resonance (HR-MR). Compared with MR imaging, CT-based techniques have the advantage of directly visualizing the bone in the axial skeleton, with high spatial resolution, but the disadvantage of delivering a considerable radiation dose. Micro-CT (μCT), which provides a higher resolution of the microstructure and is principally applicable in vitro, has undergone technological advances such that it is now able to elucidate the physiological skeletal change mechanisms associated with aging and determine the effects of therapeutic intervention on the bone microstructure. In particular, synchrotron μCT (SR-CT) provides a more detailed view of trabecular structure at the nano-level. For the assessment of hip geometry, DXA-based hip structure analysis (HSA) and CT-based HSA have been developed. DXA-based HSA is a convenient tool for analyzing biomechanical properties and for assuming cross-sectional hip geometry based on two-dimensional (2D) data, whereas CT-based HSA provides these parameters three-dimensionally in robust relationship with biomechanical properties, at the cost of greater radiation exposure and the lengthy time required for the analytical procedure. Further progress in bone imaging technology is promising to bring new aspects of bone structure in relation to bone strength to light, and to establish a means for analyzing bone structural properties in the everyday clinical setting.

  15. In vivo behavior of surface modified Ti6Al7Nb alloys used in selective laser melting for custom-made implants. A preliminary study.

    PubMed

    Rotaru, H; Armencea, G; Spîrchez, Diana; Berce, C; Marcu, Teodora; Leordean, D; Kim, Seong Gon; Lee, Sang Woon; Dinu, C; Băciuţ, G; Băciuţ, Mihaela

    2013-01-01

    The objectives of this study were to test the biocompatibility and to evaluate the osseointegration of Titanium-Aluminum-Niobium (Ti6Al7Nb) alloy used in the manufacturing of personalized implants with selective laser melting (SLM) technology and to compare the growth viability of osteoblastic-like cells on different Ti6Al7Nb alloy samples (plain, coated with hydroxyapatite or SiO2-TiO2) implanted into the cranial bone of Wistar rats. In terms of biocompatibility, the cone-beam computer-tomography head scans taken at the moment of sacrifice of each group (one, two and three months) showed no implant displacement, no osteolysis and no liquid collection around the implants. At one month, around all types of implants new bone formation was noticed, although around the plain Ti6Al7Nb implant a large amount of powder debris was present. Still, no inflammatory reaction was seen. At two months, the distance between the implants and the calvarial bone margins diminished. A thin layer of fibrous tissue was noticed around the Ti6Al7Nb implant coated with hydroxyapatite but no bone contact was achieved. In the group sacrificed at three months there was still no bone contact, but noticeable were the SiO2-TiO2. In the group sacrificed at three months SiO2-TiO2 particles detached from the implant and completely integrated in the tissue were noticeable. All results suggested that the Ti6Al7Nb alloy with or without infiltration is well biologically tolerated.

  16. Spontaneous aortoenteric fistula involving the sigmoid: A case report and review of literature

    PubMed Central

    Karthaus, Eleonora G.; Post, Ivo C.J.H.; Akkersdijk, George J.M.

    2015-01-01

    Introduction Primary aortoenteric fistula (PAEF) is a pathological communication between the aorta and any portion of the gastrointestinal tract. The pathology is very rare and easily overlooked during the diagnostic process. Presentation of Case We report the exceptional case of an 86-year-old man with episodes of abdominal pain and rectal bleeding of unknown cause over a period of 1,5 months due to a PAEF to the sigmoid. A sigmoidectomy was performed and a rifampicin-soaked aortic graft was placed. The patient had an uneventful post-operative recovery. The duration of symptoms, the anatomic location of the fistula and the outcome after surgery makes this case unique. Discussion With an incidence of 0.04–0.07% in all patients with aortic aneurysms a PAEF is very rare. Only 2% of PAEF's involves the sigmoid. The most common cause is an atherosclerotic aortic aneurysm. Patients with PAEF can present with a triad of symptoms including gastrointestinal bleeding, abdominal pain and a pulsating mass. A contrast-enhanced computer-tomography scan (CTa) is the most accurate tool to demonstrate a PAEF. Without a strong clinical suspicion, diagnosing a PAEF is hard and frequently delayed. The overall PAEF-related mortality is high (61–100%) and decreases after surgery (30–40%). Conclusion A primary aortoenteric fistula involving the sigmoid is very rare. Clinical presentation can vary, diagnosis can be difficult and surgical options may differ. Even with low suspicion of PAEF, we recommend performing a CTa. With a high overall mortality of more than 60% due to exsanguinating, surgical treatment is always indicated. PMID:26741274

  17. Radiological Outcomes and Operative Time following Total Knee Arthroplasty using Accelerometer-based, Portable Navigation versus Conventional Inter-Medullary Alignment Guides

    PubMed Central

    MacDessi, Samuel; Solayar, GN; Thatcher, N; Chen, Darren B

    2016-01-01

    Objectives: Accelerometer-based, portable navigation instrumentation is a new method of achieving desired resection alignments in total knee arthroplasty (TKA). Methods: After randomisation and the application of exclusion criteria, 79 knees were analysed. 42 patients which underwent TKA using conventional intra-medullary (IM) alignment guides were compared to 37 patients with the use of accelerometer-based, portable navigation device (KneeAlign; OrthoAlign Inc, Aliso Viejo, California). Radiographic results were obtained from post-operative computer-tomography following the CT Perth Protocol. Results: In the IM cohort, 81.0% of patients had a coronal alignment within 3° of a neutral mechanical axis (vs 83.8% with KneeAlign, p=0.74), 81.0% had a femoral coronal alignment within 2° of perpendicular to the femoral mechanical axis (vs 89.2% with KneeAlign, p=0.31), and 92.9% had a tibial coronal alignment within 2° of perpendicular to the tibial mechanical axis (vs 81.1% with KneeAlign, p=0.12). Regarding sagittal alignment, the IM cohort had 90.5% of patients with femoral component alignment within 2° of optimum (vs 91.9% with KneeAlign, p=0.83) and 92.9% had a tibial component alignment within 2° of the optimal tibial slope (vs 89.2% with KneeAlign, p=0.57). The mean tourniquet time (from incision to completion of coronal bone resections) in the IM cohort was 16.5± 8.9 minutes vs 22.2 ± 7.6 minutes in the KneeAlign cohort (p<0.003). Conclusion: Accelerometer-based, portable navigation has a statistically similar outcome in alignment following TKA as IM guides. It is noted that using the portable navigation device does prolong surgical time compared to conventional IM surgery and this may be due to the learning curve.

  18. Incidence and severity of atherosclerotic cardiovascular artery disease in patients undergoing TAVI.

    PubMed

    Fusini, Laura; Mirea, Oana; Tamborini, Gloria; Muratori, Manuela; Gripari, Paola; Cefalù, Claudia; Ghulam Ali, Sarah; Maffessanti, Francesco; Andreini, Daniele; Pontone, Gianluca; Bartorelli, Antonio L; Alamanni, Francesco; Agrifoglio, Marco; Pepi, Mauro

    2015-06-01

    Transcatheter aortic valve implantation (TAVI) has extended the treatment options for severe, symptomatic aortic valve stenosis (AS). Risk factors for AS have been shown to be similar to atherosclerosis. Consequently, coronary artery disease (CAD), peripheral vascular and carotid artery diseases are often found concurrently with diagnostic, procedural and prognostic implications. This study sought to describe comprehensive vascular assessment in terms of prevalence, severity and correlations in TAVI candidates. A total of 323 patients (81 ± 6 years) undergoing TAVI were enrolled. Vascular pathologies were evaluated by invasive coronary angiography, computer-tomography (abdominal aorta, renal, iliac and femoral arteries), echo-color Doppler ultrasound (carotid artery), and transoesophageal echocardiography (thoracic aorta). CAD was found in 173 (54%) patients, of which 65 (38%) had 1-vessel, 45 (26%) 2-vessel and 59 (34%) 3-vessel disease. Carotid artery disease was present in 33.6% patients, of which 23.6% unilateral and 10.0% bilateral. Iliac, femoral and renal stenosis were found in 29.2%, 22.0%, and 4.7%, respectively. Cardiovascular risk factor and gender correlated with CAD. CAD patients presented more frequently with significant stenosis (luminal narrowing ≥ 50%) of at least one other district. Multi-districts significant stenosis stratified patients on long-term survival and the coexistence of 3-districts involvement with CAD negatively impacts on mortality. Multimodality imaging assessment shows that coronary, carotid, and peripheral artery disease are often found concurrently in patients undergoing TAVI. Several risk factors and gender correlate with the presence and severity of CAD and peripheral pathologies. Long-term mortality is increased in patients with a more compromised vascular situation. PMID:25805046

  19. In vivo behavior of surface modified Ti6Al7Nb alloys used in selective laser melting for custom-made implants. A preliminary study.

    PubMed

    Rotaru, H; Armencea, G; Spîrchez, Diana; Berce, C; Marcu, Teodora; Leordean, D; Kim, Seong Gon; Lee, Sang Woon; Dinu, C; Băciuţ, G; Băciuţ, Mihaela

    2013-01-01

    The objectives of this study were to test the biocompatibility and to evaluate the osseointegration of Titanium-Aluminum-Niobium (Ti6Al7Nb) alloy used in the manufacturing of personalized implants with selective laser melting (SLM) technology and to compare the growth viability of osteoblastic-like cells on different Ti6Al7Nb alloy samples (plain, coated with hydroxyapatite or SiO2-TiO2) implanted into the cranial bone of Wistar rats. In terms of biocompatibility, the cone-beam computer-tomography head scans taken at the moment of sacrifice of each group (one, two and three months) showed no implant displacement, no osteolysis and no liquid collection around the implants. At one month, around all types of implants new bone formation was noticed, although around the plain Ti6Al7Nb implant a large amount of powder debris was present. Still, no inflammatory reaction was seen. At two months, the distance between the implants and the calvarial bone margins diminished. A thin layer of fibrous tissue was noticed around the Ti6Al7Nb implant coated with hydroxyapatite but no bone contact was achieved. In the group sacrificed at three months there was still no bone contact, but noticeable were the SiO2-TiO2. In the group sacrificed at three months SiO2-TiO2 particles detached from the implant and completely integrated in the tissue were noticeable. All results suggested that the Ti6Al7Nb alloy with or without infiltration is well biologically tolerated. PMID:24322029

  20. Toxic inner ear lesion following otitis media with effusion: a comparative CT-study regarding the morphology of the inner ear.

    PubMed

    Wilhelm, Thomas; Stelzer, Tim; Wiegand, Susanne; Güldner, Christian; Teymoortash, Afshin; Günzel, Thomas; Hagen, Rudolf

    2015-12-01

    Viral infections of the upper respiratory airways can lead to a delayed viral otitis media (VOM) caused by a diffusion of viruses/virus particles through the round window membrane and resulting in sensorineural hearing loss. The treatment of choice is immediate paracentesis, evacuation of all fluids from the middle ear cavity, and haemorrheological infusions. However, in some cases, persistent symptoms may be an indication for a surgical approach using mastoidectomy. In high-resolution computed tomography, an extended small-sized pneumatisation of the mastoid cells with complete shading was found in these non-responsive cases. Therefore, a direct means of inner ear affliction through weak parts of the labyrinthine bone may be hypothesised. Patients suffering from a toxic inner ear lesion (TIEL) following a common cold, treated over a 10-year period in a Tertiary Care Centre (N = 52, 57 ears), were identified and the morphological characteristics of the temporal bones of affected patients were examined by means of high-resolution computed tomography (hrCT). The findings were compared with a matched control group of 64 normal ears (CONT). Measurements included the grade of pneumatisation, distances within the temporal bones and Hounsfield units (HU) at defined anatomical structures. In the TIEL group, we found a small-sized pneumatisation in 79.4 % and a medium-sized pneumatisation in 10.9 %, thus differing from the CONT group and the literature data. Thickness of the bone wall of the lateral semicircular canal (LSC) and distances within the aditus ad antrum were significantly reduced in the TIEL group. HU's were markedly lower in the TIEL group at the precochlea, the LSC, and dorsolateral to the promentia of the LSC. There was a correlation between the HU's at the prominentia of the LSC and the hearing loss (p = 0.002). Persisting interosseous globuli, as described in 1897 by Paul Manasse, form an osseochondral network within the otic capsule and may be responsible

  1. Consistent Evaluation of ACOS-GOSAT, BESD-SCIAMACHY, CarbonTracker, and MACC Through Comparisons to TCCON

    NASA Technical Reports Server (NTRS)

    Kulawik, Susan; Wunch, Debra; O’Dell, Christopher; Frankenberg, Christian; Reuter, Maximilian; Chevallier, Frederic; Oda, Tomohiro; Sherlock, Vanessa; Buchwitz, Michael; Osterman, Greg; Miller, Charles E.; Iraci, Laura T.; Wolf, Joyce

    2016-01-01

    -to-year variability of 0.3 parts per million, with biases larger than the TCCON predicted bias uncertainty of 0.4 parts per million at many stations. We find that GOSAT and CT2013b under-predict the seasonal cycle amplitude in the Northern Hemisphere (NH) between 46 and 53 degrees North latitude, MACC over-predicts between 26 and 37 degrees North latitude, and CT2013b under-predicts the seasonal cycle amplitude in the Southern Hemisphere (SH). The seasonal cycle phase indicates whether a data set or model lags another data set in time. We find that the GOSAT measurements improve the seasonal cycle phase substantially over the prior while SCIAMACHY measurements improve the phase significantly for just two of seven sites. The models reproduce the measured seasonal cycle phase well except for at Lauder_125HR (CT2013b) and Darwin (MACC). We compare the variability within 1 day between TCCON and models in June-July-August; there is correlation between 0.2 and 0.8 in the NH, with models showing 10-50 percent the variability of TCCON at different stations and CT2013b showing more variability than MACC. This paper highlights findings that provide inputs to estimate flux errors in model assimilations, and places where models and satellites need further investigation, e.g., the SH for models and 45-67 degrees North latitude for GOSAT and CT2013b.

  2. Consistent evaluation of ACOS-GOSAT, BESD-SCIAMACHY, CarbonTracker, and MACC through comparisons to TCCON

    NASA Astrophysics Data System (ADS)

    Kulawik, Susan; Wunch, Debra; O'Dell, Christopher; Frankenberg, Christian; Reuter, Maximilian; Oda, Tomohiro; Chevallier, Frederic; Sherlock, Vanessa; Buchwitz, Michael; Osterman, Greg; Miller, Charles E.; Wennberg, Paul O.; Griffith, David; Morino, Isamu; Dubey, Manvendra K.; Deutscher, Nicholas M.; Notholt, Justus; Hase, Frank; Warneke, Thorsten; Sussmann, Ralf; Robinson, John; Strong, Kimberly; Schneider, Matthias; De Mazière, Martine; Shiomi, Kei; Feist, Dietrich G.; Iraci, Laura T.; Wolf, Joyce

    2016-02-01

    -predicted bias uncertainty of 0.4 ppm at many stations. We find that GOSAT and CT2013b underpredict the seasonal cycle amplitude in the Northern Hemisphere (NH) between 46 and 53° N, MACC overpredicts between 26 and 37° N, and CT2013b underpredicts the seasonal cycle amplitude in the Southern Hemisphere (SH). The seasonal cycle phase indicates whether a data set or model lags another data set in time. We find that the GOSAT measurements improve the seasonal cycle phase substantially over the prior while SCIAMACHY measurements improve the phase significantly for just two of seven sites. The models reproduce the measured seasonal cycle phase well except for at Lauder_125HR (CT2013b) and Darwin (MACC). We compare the variability within 1 day between TCCON and models in JJA; there is correlation between 0.2 and 0.8 in the NH, with models showing 10-50 % the variability of TCCON at different stations and CT2013b showing more variability than MACC. This paper highlights findings that provide inputs to estimate flux errors in model assimilations, and places where models and satellites need further investigation, e.g., the SH for models and 45-67° N for GOSAT and CT2013b.