Browsing by Subject "CEREBRAL WHITE-MATTER"

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  • Remes, Tiina Maria; Suo-Palosaari, Maria Helena; Koskenkorva, Päivi K. T.; Sutela, Anna K.; Toiviainen-Salo, Sanna-Maria; Arikoski, Pekka M.; Arola, Mikko O.; Heikkilä, Vesa-Pekka; Kapanen, Mika; Lähteenmäki, Päivi Maria; Lönnqvist, Tuula R. I.; Niiniviita, Hannele; Pokka, Tytti M-L; Porra, Liisa; Riikonen, V. Pekka; Seppälä, Jan; Sirkiä, Kirsti H.; Vanhanen, Antti; Rantala, Heikki M. J.; Harila-Saari, Arja H.; Ojaniemi, Marja K. (2020)
    Background. Cranial radiotherapy may damage the cerebral vasculature. The aim of this study was to understand the prevalence and risk factors of cerebrovascular disease (CVD) and white matter hyperintensities (WMHs) in childhood brain tumors (CBT) survivors treated with radiotherapy. Methods. Seventy CBT survivors who received radiotherapy were enrolled in a cross-sectional study at a median 20 years after radiotherapy cessation. The prevalence of and risk factors for CVD were investigated using MRI, MRA, and laboratory testing. Tumors, their treatment, and stroke-related data were retrieved from patients' files. Results. Forty-four individuals (63%) had CVD at a median age of 27 years (range, 16-43 years). The prevalence rates at 20 years for CVD, small-vessel disease, and large-vessel disease were 52%, 38%, and 16%, respectively. Ischemic infarcts were diagnosed in 6 survivors, and cerebral hemorrhage in 2. Lacunar infarcts were present in 7, periventricular or deep WMHs in 34 (49%), and mineralizing microangiopathy in 21 (30%) survivors. Multiple pathologies were detected in 44% of the participants, and most lesions were located in a high-dose radiation area. Higher blood pressure was associated with CVD and a presence of WMHs. Higher cholesterol levels increased the risk of ischemic infarcts and WMHs, and lower levels of high-density lipoprotein and higher waist circumference increased the risk of lacunar infarcts. Conclusions. Treating CBTs with radiotherapy increases the risk of early CVD and WMHs in young adult survivors. These results suggest an urgent need for investigating CVD prevention in CBT patients.
  • Brandstack, Nina; Kurki, T.; Laalo, J.; Kauko, T.; Tenovuo, O. (2016)
    Reproducibility of two different methods for quantifying fiber tracts by using a diffusion tensor imaging (DTI) sequence suitable for clinical magnetic resonance imaging (MRI) protocols was evaluated. DTI of 15 subjects was used to analyze intra-rater and inter-rater reproducibility. Another 10 subjects underwent MRI twice for assessment of between-scan reliability. Ten long association tracts were defined by fiber tracking using inclusion and exclusion regions of interest (ROIs). Whole-tract analysis and tractography-based core analysis were performed, and the effect of fractional anisotropy (FA 0.15/0.30) and turning angle threshold (27A degrees/60A degrees) on reproducibility was evaluated. Additionally, ROI measurements were performed in the core of the tracts. For the tract-based methods, intra-rater and inter-rater reliabilities of FA and mean diffusivity (MD) measurements were excellent. Between-scan reproducibility was good or excellent in 127 of 130 of the measurements. There was no systematic difference in the reproducibility of the FA, MD, and volume measurements depending on the FA or turning angle threshold. For the cross-sectional ROI measurements, reliability showed large variation from poor to excellent depending on the tract. Compared with the commonly used cross-sectional core ROI method, the tract-based analyses seem to be a more robust way to identify and measure white matter tracts of interest, and provide a novel reproducible tool to perform core analysis.