A novel anisotropic fast marching method and its application to blood flow computation in phase-contrast MRI.

BACKGROUND: Phase-contrast MRI (PC MRI) can be used to assess blood flow dynamics noninvasively inside the human body. The acquired images can be reconstructed into flow vector fields. Traditionally, streamlines can be computed based on the vector fields to visualize flow patterns and particle trajectories. OBJECTIVES: The traditional methods may give a false impression of precision, as they do not consider the measurement uncertainty in the PC MRI images. In our prior work, we incorporated the uncertainty of the measurement into the computation of particle trajectories. METHODS: As a major part of the contribution, a novel numerical scheme for solving the anisotropic Fast Marching problem is presented. A computing time comparison to state-of-the-art methods is conducted on artificial tensor fields. A visual comparison of healthy to pathological blood flow patterns is given. RESULTS: The comparison shows that the novel anisotropic Fast Marching solver outperforms previous schemes in terms of computing time. The visual comparison of flow patterns directly visualizes large deviations of pathological flow from healthy flow. CONCLUSIONS: The novel anisotropic Fast Marching solver efficiently resolves even strongly anisotropic path costs. The visualization method enables the user to assess the uncertainty of particle trajectories derived from PC MRI images.

Primary central nervous system lymphoma treated with high-dose methotrexate, high-dose busulfan/thiotepa, autologous stem-cell transplantation and response-adapted whole-brain radiotherapy: results of the multicenter Ostdeutsche Studiengruppe Hamato-Onkologie OSHO-53 phase II study.

BACKGROUND: We investigated the efficacy and safety of tandem high-dose methotrexate (HD-MTX) induction followed by high-dose busulfan/thiotepa (HD-BuTT) with autologous peripheral blood stem-cell transplantation (aPBSCT) and response-adapted whole-brain radiation therapy (WBRT) in patients with newly diagnosed primary central nervous system lymphoma. PATIENTS AND METHODS: Twenty-three patients were treated with HD-MTX on days 1 and 10. In case of at least a partial remission (PR), HD-BuTT followed by aPBSCT was given. Patients without response to induction or without complete remission (CR) after HD-BuTT received WBRT. RESULTS: Sixteen patients received HD-MTX and HD-BuTT achieving a CR/PR rate of 69%/13%. CR/PR rates for all patients (n = 23) were 70%/13%. There were three deaths during therapy. With longer follow-up three neurotoxic deaths occurred in irradiated patients (n = 9), while no persistent neurotoxicity was seen after HD-BuTT without subsequent WBRT. At a median follow-up of 15 months (range 1-69) median event-free survival (EFS) and overall survival (OS) for all patients were 17 and 20 months (Kaplan-Meier), after HD-BuTT 27 months and "not reached", respectively. Estimated 2-year EFS and OS were 45% and 48% for all patients versus 56% and 61% for the HD-BuTT group, respectively. CONCLUSION: MTX induction followed by HD-BuTT is an effective and very short time-on-treatment regimen. Median survival for patients treated with high-dose chemotherapy is not reached yet. The induction regimen needs optimisation. In this study WBRT was associated with a high incidence of severe neurotoxicity.

[Tests for anaerobes in patients with hemoblastosis]. / Anaerobieruntersuchungen bei Hämoblastosepatienten.

A simplified control programme for the selective decontamination is proposed. Before the beginning of the attendance a microbial "large scale programme" is applicated in order to determine the quantitative and qualitative composition of the small intestinal and of the large intestinal flora on aerobic and anaerobic cultural conditions. During the attendance a "short-time programme" is applicated. At this on the basis of an aerobic cultural method and by the help of a direct microscopic numeration the flora is determined in its quantitative composition. At the end of an attendance the microbial "large-scale programme" is repeated.

[The significance of Candida antigen detection in internal medicine and surgical patients]. / Zur Aussagekraft von Candida-Antigen-Nachweisen bei internistisch-chirurgischen Patienten.

Three different Candida antigen tests were studied in internal-surgical patients: two tests for Candida mannan antigen (C-Mannan-Dresden, Pastorex-Candida and Cand-Tec test for cytoplasmatic antigen. Most positive findings could be seen by both tests for mannan. In cases with increased occurrence of fungi in feces, sputum, urine, and mouth smears the tests differently became negative. Some clinical cases are discussed. With increased positivity of titer courses of all 3 antigen tests the probability of detection of an endomycosis also increased.