Energy-resolved visibility analysis of grating interferometers operated at polychromatic X-ray sources.

Grating interferometry has been successfully adapted at standard X-ray tubes and is a promising candidate for a broad use of phase-contrast imaging in medical diagnostics or industrial testing. The achievable image quality using this technique is mainly dependent on the interferometer performance with the interferometric visibility as crucial parameter. The presented study deals with experimental investigations of the spectral dependence of the visibility in order to understand the interaction between the single contributing energies. Especially for the choice which type of setup has to be preferred using a polychromatic source, this knowledge is highly relevant. Our results affirm previous findings from theoretical investigations but also show that measurements of the spectral contributions to the visibility are necessary to fully characterize and optimize a grating interferometer and cannot be replaced by only relying on simulated data up to now.

[Thrombus of the right ventricle simulating a cardiac tumor--case report]. / Skrzeplina w prawej komorze symulujaca guz serca--opis przypadku.

A nine day infant with Down syndrome and congenital heart disease is presented in whom the course of neonatal sepsis was complicated by the presence of difficult to diagnose pathological masses in the right ventricle. The etiology of pathological masses was difficult to establish in survival investigations. Histopathological examinations revealed the presence of thrombus in the right heart and foci of granulation on a muscle of right ventricle outflow, probably after a septic embolus.

[Acute leukemia in children with Down syndrome: analysis of cases]. / Ostra bialaczka u dzieci z zespolem Downa--analiza przypadków wlasnych.

An analysis of clinical and laboratory parameters and the results of treatment of 14 children with Down Syndrome and acute leukaemia was performed. The children were treated between 1986-1997. Their age ranged from 1 day to 13 years (average 5.5). There were 9 girls and 5 boys. Four of them had congenital heart disease. ALL was observed in 10, AML in 3 and TAM (Transient Abnormal Myelopoesis) in 1. Half of the children with ALL was classified as L1 according to FAB with the majority of common phenotypes and M6 in ANLL group. Remission was achieved in all ALL patients, six of them are still free of symptoms, the remaining four died of brain haemorrhage as a consequence of myelosuppression. Only 1 of 3 children with ANLL achieved remission. The child died of cardiac arrest after induction phase of BFM 95 programme (ADE). The 2 remaining children with ANLL also died of circulation failure before initiation of chemotherapy. The children had complicated cyanotic heart disease. The neonate with TAM is in clinical and hematological remission. In conclusion all children with ALL achieved hematological remission but tolerance of treatment was a problem. The majority of patients had diminished bone marrow reserve. Mortality was frequently related to circulatory failure in children with associated heart defects. It seems necessary to discuss the modification of accepted programmes for leukemia for the treatment of children with Down Syndrome.

[The clinical course of fungal urinary tract infection in neonates]. / Grzybica ukladu moczowego noworodków--obserwacje wlasne.

The authors present the clinical course of 8 cases of fungal infection of the urinary tract in newborns. Three of the investigated children were premature or with intrauterine hypotrophy, a congenital defect of the urinary tract was detected in one child. In 5 cases the fungal infection followed bacterial septicaemia. Two of the 8 children required peritoneal dialysis, another two required insertion of intravenous catheters for parenteral feeding, and four required bladder catheterisation. The diagnosis of fungal urinary tract infection was established on the basis of urine culture, the presence of specific serum anti-candida antibodies and results of ultrasonographic examination (vs). In 7 of 8 cases the possibility of fungal infection was suggested by US examination. Seven children were treated with fluconazole combined with 5-fluorocytosine, one was treated with fluconazole. Pyelostomy was performed, in two of the patients all of them received supportive treatment. Our clinical observations point to the necessity of prophylaxis in case of predisposing factors to fungal infection and the use of abdominal ultrasonography for detection of early stages of fungal urinary tract infection.

Quantitative electron density characterization of soft tissue substitute plastic materials using grating-based x-ray phase-contrast imaging.

Many scientific research areas rely on accurate electron density characterization of various materials. For instance in X-ray optics and radiation therapy, there is a need for a fast and reliable technique to quantitatively characterize samples for electron density. We present how a precise measurement of electron density can be performed using an X-ray phase-contrast grating interferometer in a radiographic mode of a homogenous sample in a controlled geometry. A batch of various plastic materials was characterized quantitatively and compared with calculated results. We found that the measured electron densities closely match theoretical values. The technique yields comparable results between a monochromatic and a polychromatic X-ray source. Measured electron densities can be further used to design dedicated X-ray phase contrast phantoms and the additional information on small angle scattering should be taken into account in order to exclude unsuitable materials.

Quantitative breast tissue characterization using grating-based x-ray phase-contrast imaging.

X-ray phase-contrast imaging has received growing interest in recent years due to its high capability in visualizing soft tissue. Breast imaging became the focus of particular attention as it is considered the most promising candidate for a first clinical application of this contrast modality. In this study, we investigate quantitative breast tissue characterization using grating-based phase-contrast computed tomography (CT) at conventional polychromatic x-ray sources. Different breast specimens have been scanned at a laboratory phase-contrast imaging setup and were correlated to histopathology. Ascertained tumor types include phylloides tumor, fibroadenoma and infiltrating lobular carcinoma. Identified tissue types comprising adipose, fibroglandular and tumor tissue have been analyzed in terms of phase-contrast Hounsfield units and are compared to high-quality, high-resolution data obtained with monochromatic synchrotron radiation, as well as calculated values based on tabulated tissue properties. The results give a good impression of the method's prospects and limitations for potential tumor detection and the associated demands on such a phase-contrast breast CT system. Furthermore, the evaluated quantitative tissue values serve as a reference for simulations and the design of dedicated phantoms for phase-contrast mammography.

Cellular and humoral components of neutrophil chemotaxis in neonates with bacterial infection.

The initial stage of infection is characterized by both, changes in leucocyte function and humoral factors activity. In this paper we evaluated random migration and chemotaxis of neutrophils and serum ability to generate humoral factors influencing the neutrophil function. The studies were performed in 51 neonates during the acute phase of bacterial infection and in the remission time. Both random migration and chemotaxis were decreased during the acute phase of disease and normalized during remission. The same was true for serum ability to generate chemotactic activity. The serum of sick neonates did not alter the mobility of neutrophils isolated from adult healthy donors and it did not influence the normal chemotactic activity. We conclude, that the handicapped locomotive abilities of neutrophils in bacterial infection are temporary, and may require in severely ill infants supportive therapy to maintain adequate cellular and humoral immunity.

[Aspergillosis of the lymphatic nodes]. / Grzybica kropidlakowa (Aspergillosis) wezlów chlonnych.

The authors emphasize fungal lesions to the lymphatic nodes confirmed by the presence of Aspergillus flavus in blood and throat smear cultures (on Sabouraud's medium) and presence of A. flavus in cytological examination of biopsy from the lymphatic node, increased number of eosinophils in peripheral blood, and infiltration of eosinophils in bone marrow and lymphatic nodes. Aspergillosis coexisted with the infection with Candida albicans and S. aureus. The treatment of recurrent tonsillitis with antibiotics and also lowered granulocyte myeloperoxidase activity with increased production of O2 peroxide ion might predispose to such fungal infection.