A preliminary study of three-dimensional reconstruction of the human osseous labyrinth from micro-computed tomography scans

The adult human temporal bone was investigated using micro-CT scans. Various aspects of the osseous labyrinth were presented in figures which are effect of the volume rendering. The 3D reconstructions were performed to visualize the cochlea and the semicircular canals embedded in the petrous bone. The final product of this study was a digital three-dimensional model of the entire osseous labyrinth which can be viewed at different angles on the computer screen

Imaging of the Wormian bones using microcomputed tomography

Wormian bones are irregular ossicles of small size and reveal fractal pattern of their edges. Their anatomy was visualized in volumetric reconstructions obtained from a series of micro-CT scans. In visual evaluation Wormian bones showed typical anatomy for the calvarial bones. They revealed three-layer composition: the outer and the inner table of the compact bone intervening with the table of the spongy bone. Microcomputed tomography captured all details of the interdigitation of the edge being incorporated into the lambdoid suture and interlocked between opposing edges of the occipital and parietal bones. This modality provided accurate images which allowed delineating morphological differences between the compact bone and the diploe, including vascular channels

Zastosowanie rozmytych reguł wnioskowania do automatycznej klasyfikacji zapisów częstości uderzeń serca płodu w odniesieniu do stanu urodzeniowego

Objectives: Fetal monitoring based on the analysis of the fetal heart rate (FHR) signal is the most common method of biophysical assessment of fetal condition during pregnancy and labor. Visual analysis of FHR signals presents a challenge due to a complex shape of the waveforms. Therefore, computer-aided fetal monitoring systems provide a number of parameters that are the result of the quantitative analysis of the registered signals. These parameters are the basis for a qualitative assessment of the fetal condition. The guidelines for the interpretation of FHR provided by FIGO are commonly used in clinical practice. On their basis a weighted fuzzy scoring system was constructed to assess the FHR tracings using the same criteria as those applied by expert clinicians. The effectiveness of the automated classification was evaluated in relation to the fetal outcome assessed by Apgar score. Material and methods: The proposed automated system for fuzzy classification is an extension of the scoring systems used for qualitative evaluation of the FHR tracings. A single fuzzy rule of the system corresponds to a single evaluation principle of a signal parameter derived from the FIGO guidelines. The inputs of the fuzzy system are the values of quantitative parameters of the FHR signal, whereas the system output, which is calculated in the process of fuzzy inference, defines the interpretation of the FHR tracing. The fuzzy evaluation process is a kind of diagnostic test, giving a negative or a positive result that can be compared with the fetal outcome assessment. The present retrospective study included a set of 2124 one-hour antenatal FHR tracings derived from 333 patients, recorded between 24 and 44 weeks of gestation (mean gestational age: 36 weeks). Various approaches for the research data analysis, depending on the method of interpretation of the individual patient-tracing relation, were used in the investigation. The quality of the fuzzy analysis was defined by the number of correct classifications (CC) and the additional index QI – the geometric mean of the sensitivity and specificity values. Results: The effectiveness of the fetal assessment varied, depending on the assumed relation between a patient and a set of her tracings. The approach, based on a common assessment of the whole set of tracings recorded for a single patient, provided the highest quality of automated classification. The best results (CC = 70.9% and QI = 84.0%) confirmed the possibility of predicting the neonatal outcome using the proposed fuzzy system based on the FIGO guidelines. Conclusions: It is possible to enhance the process of the fetal condition assessment with classification of the FHR records through the implementation of the heuristic rules of inference in the fuzzy signal processing algorithms.Cel pracy: Monitorowanie płodu na podstawie analizy sygnału czynności serca płodu (FHR) jest najczęściej stosowaną metodą biofizycznej oceny stanu płodu w czasie ciąży i porodu. Wzrokowa analiza krzywej FHR jest trudna z uwagi na jej złożony kształt. Z tego względu, komputerowo-wspomagane systemy monitorowania stanu płodu dostarczają szeregu parametrów będących rezultatem ilościowej analizy rejestrowanego sygnału. Parametry te są podstawą dla jakościowej oceny stanu płodu. Do najczęściej stosowanych wytycznych, określających sposób interpretacji sygnału FHR należą kryteria określone przez FIGO. Na ich podstawie skonstruowano ważony rozmyty system punktowy, którego zadaniem jest określenie stanu płodu na podstawie kryteriów oceny, jakimi posługuje się ekspert kliniczny. W pracy przedstawiono badania nad zgodnością rozmytej klasyfikacji z oceną stanu płodu wyznaczaną na podstawie punktacji Apgar. Materiał i metody: Proponowany system do automatycznej, rozmytej klasyfikacji stanowi rozwinięcie idei skal punktowych wykorzystywanych do jakościowej oceny zapisów czynności serca płodu. Za pomocą jednej reguły rozmytej modelowana jest zasada oceny pojedynczego parametru opisu ilościowego sygnału FHR zgodnie z wytycznymi FIGO. Wejściami systemu rozmytego są wartości parametrów ilościowych sygnału FHR, a stan wyjścia, wyznaczany w procesie wnioskowania rozmytego, definiuje interpretację zapisu. Proces rozmytej oceny sygnału jest rodzajem testu diagnostycznego, którego wynik, negatywny lub pozytywny, można porównać z oceną stanu urodzeniowego noworodka. Badaniem retrospektywnym objęto zbiór 2124 godzinnych zapisów ciążowych pochodzących od 333 pacjentek, zarejestrowanych pomiędzy 24 a 44 tygodniem ciąży (średni wiek ciążowy to 36 tygodni). W eksperymentach zastosowano różne konstrukcje zbiorów danych, w zależności od przyjętego sposobu interpretacji zbioru sygnałów zarejestrowanych dla pojedynczej pacjentki. Jakość rozmytej analizy automatycznej oceniano na podstawie liczby poprawnych klasyfikacji CC oraz wskaźnika QI będącego średnią geometryczną czułości oraz swoistości. Wyniki: W zależności od przyjętej metody analizy zbioru danych otrzymano różną skuteczność oceny stanu płodu. Podejście, w którym określano jedną wspólną ocenę dla całego zbioru zapisów zarejestrowanych dla pojedynczej pacjentki, pozwoliło na uzyskanie najwyższej jakości automatycznej klasyfikacji. Najlepsze z uzyskanych wyników (CC = 70.9% i QI = 84.0%) potwierdzają możliwość predykcji stanu urodzeniowego płodu na podstawie rozmytego wnioskowania opartego na wytycznych FIGO. Wnioski: Istnieje możliwość wspomagania procesu diagnostyki stanu płodu przez zastosowanie systemu rozmytej klasyfikacji sygnałów FHR, opartego o heurystyczne reguły wnioskowania właściwe doświadczonemu klinicyście

Three dimensional visualisation and morphometry of bone samples studied in microcomputed tomography (micro-CT)

This article highlights the utility of micro-computed tomography (micro-CT) for characterisingmicroscale bone morphology. For this purpose we tested selected samplesof the human bones (Wormian bone, rib, lumbar vertebra) to reconstruct externaland internal morphological features. Selected bony samples were investigatedusing a micro-CT scanner (Skyscan 1172, N.V., Aartselaar, Belgium). The imageresolution of scans varied from 5 to 27 \mu m/pixel depending on the bone sample. We used CTvox software (by Skyscan) to perform volume rendering of the samples. Further, 3-dimensional geometrical models were reconstructed using the CTvol application. Such models enabled graphical distinction between osseouscomponents of various morphology and were used to visualise the Haversian canalsystem inside the compact bone of the rib. Applying a modified transfer functionfor volume rendering we presented the overall morphology of the Wormian boneand small vascular channels penetrating its interior. As an example of quantitativeanalysis based on micro-CT scans we compared the trabecular structure of thelumbar vertebrae with CTAn software. Significant differences in percent bonevolume (BV/TV) were determined. Micro-CT was found to be a very accurate andhelpful method to study small anatomical structures of the bones in micro scale

Quantum transport and mobility spectrum of topological carriers in (001) SnTe/PbTe heterojunctions

Measurements of magnetotransport in SnTe/PbTe heterojunctions grown by the MBE technique on (001) undoped CdTe substrates were performed. At low magnetic fields, quantum corrections to conductivity were observed that may be attributed to the presence of topological states at the junction interface. For a sample with 5 nm thick SnTe layer, the data analysis suggests that midgap states are actually gapped. However, the phase coherence effects in 10 nm and 20 nm SnTe/PbTe samples are fully explained assuming existence of gapless Dirac cones. Magnetotransport at higher magnetic fields is described in the framework of mobility spectrum analysis (MSA). We demonstrate that the electron- and hole-like peaks observed simultaneously for all SnTe/PbTe heterojunctions may originate from the concave and convex parts of the energy isosurface for topological states -- and not from the existence of quasiparticles both carrying negative and positive charges. This interpretation is supported by numerical calculations of conductivity tensor components for gapless (100) Dirac cones, performed within a classical model and based on the solutions of Boltzmann transport equation. Our approach shows the feasibility of MSA in application to magnetotransport measurements on topological matter

Ossification of the ligamentum flavum of the lumbosacral spine in the polish hospitalized population : a prospective cohort study

The aim of this study was to assess the prevalence, clinical features and distribution of lumbosacral ossifications of the ligamentum flavum (OLF), using MRI, CT and microCT, in hospitalized Polish patients. Patients were recruited prospectively between January 2011 and January 2013. Patients were further qualified to the study group only if CT or MRI of the lumbosacral region detected OLF. Level of OLF excision was determined by the localization of spinal stenosis. After excision the LF fragments containing OLF were stored in a 4% solution of formaldehyde until microCT assessment. A total of 184 agreed to take part in the study. In 50 patients (27.2%) OLF were found. Thus, the study group consisted of 17 women (34%) and 33 men, with a mean age of 55.4 \pm 17.2 years. OLF occurred more often in men (66%) than in women (34%) (p = 0.0014). The most common site for the localization of OLF in women, as well as in men was the L5/S1 level (60% and 53.3% respectively). The mean volume of OLF was 3.87\pm 5.27 mm^{3}\left ( 4.66 \pm 5.71 mm^{3} vs. 1.27 \pm 2.19 mm^{3}, in men and women respectively; p = 0.023 \right ). The LF were thickened in 21 (42%) patients. The mean volume of OLF in patients with normal LF was 4.78\pm 5.95 mm^{3} and in patients with thickened LF 5.33\pm 6.10 mm^{3} (p = 0.75). The prevalence of lumbosacral OLF in the Polish hospitalized population is very high. The most common site of their localization is the L5/S1 level. LF thickening is not associated with OLF formation

Projekt „5000 metrów nad poziomem cukru”

–