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Background and Purpose— Widespread reductions in white matter integrity are associated with cognitive dysfunction in sickle cell anemia. Silent cerebral infarction (SCI), vasculopathy (VSC), and low hemoglobin concentration (Hb) are implicated; we aimed to determine independent contributions to microstructural white matter injury and whether white matter integrity differs across arterial territories. Methods— Sixty two children with sickle cell anemia aged 6 to 19 years were prospectively studied at Muhimbili National Hospital, Tanzania. SCI± and VSC± were identified on magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) scans by 2 neuroradiologists. Tract-based spatial statistics tested for voxel-wise differences in diffusion tensor imaging metrics (ie, fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity) between SCI± and VSC± groups, with correlations between diffusion tensor imaging metrics and Hb. In tract-based spatial statistics analyses, potentially mediating factors (ie, age, sex, as well as Hb, SCI, and/or vasculopathy) were covariates. Differences in mean diffusion tensor imaging metrics across regions of interest in arterial territories were explored. Results— Compared with SCI− patients (n=45), SCI+ patients (n=17) exhibited increased radial diffusivity in multiple regions; negative relationships were observed between mean diffusivity, axial diffusivity, and Hb ( P <0.005). Compared with VSC− patients (n=49), mild (n=6) or moderate (n=7) VSC+ patients exhibited reduced fractional anisotropy in widespread regions ( P <0.05) including the anterior longitudinal fasciculi, corpus callosum, internal capsule, corona radiata, and corticospinal tracts. Overall, the posterior cerebral arterial territory had higher mean mean diffusivity and mean radial diffusivity than the anterior and middle cerebral arterial territories, although no patient had vasculopathy in this area. There was an interaction between territory and vasculopathy. Conclusions— SCI, vasculopathy, and Hb are independent risk factors, and thus treatment targets, for diffuse white matter injury in patients with sickle cell anemia. Exacerbation of hemodynamic stress may play a role.

Record neurologic history and perform thorough examination. c Use TCD ultrasonography to detect risk of stroke (Fenella Kirkham; United Kingdom) (Figure 1). c Interpret conventional brain MRI scans and magnetic resonance angiography (MRA) images in SCD (Dawn Saunders, United Kingdom/United States [Figure 2C]) (Figures 3 and 4).

This book contains the abstracts of the papers/posters presented at the Tanzania Health Summit 2020 (THS-2020) Organized by the Ministry of Health Community Development, Gender, Elderly and Children (MoHCDGEC); President Office Regional Administration and Local Government (PORALG); Ministry of Health, Social Welfare, Elderly, Gender, and Children Zanzibar; Association of Private Health Facilities in Tanzania (APHFTA); National Muslim Council of Tanzania (BAKWATA); Christian Social Services Commission (CSSC); & Tindwa Medical and Health Services (TMHS) held on 25–26 November 2020. The Tanzania Health Summit is the annual largest healthcare platform in Tanzania that attracts more than 1000 participants, national and international experts, from policymakers, health researchers, public health professionals, health insurers, medical doctors, nurses, pharmacists, private health investors, supply chain experts, and the civil society. During the three-day summit, stakeholders and decision-makers from every field in healthcare work together to find solutions to the country’s and regional health challenges and set the agenda for a healthier future.

Soft tissue imaging is heavily impaired by streaks and cupping effects associated with X-ray scatter. Quality of images from projection imaging may be improved by the use of enhanced anti-scatter grids’ designs with potency to reject significant scatter. However, optimization of grid characteristics requires investigation to improve diagnostic image quality. Transmitted scatter spatially distributed degrades images engendering need for effective scatter correction protocols. This study investigated the pre-scan scatter suppression algorithm for X-ray exposure of soft tissue equivalent phantoms over nominal energy range. Adipose tissue and polymethyl methacrylate phantoms of cross-sectional area (30 x 30) cm2 and of varying thickness from 2 to 8 cm in 1 cm increments were successively exposed using energy ranging between 20–50 kVp. Monte Carlo simulation based on FLUKA code and flair interface was used to generate an input file for execution. The source simulated five cycles of ten million photons each of annular X-ray photon beam of radius, r = 0.5 cm at fixed field of view (FOV) through anti-scatter grid on to gadolinium oxysulfide detector. The transmitted total, scatter and primary estimates were evaluated with and without grids over varying phantom thicknesses, energy and grid design features. The simulated and experimental results obtained were comparable and in agreement with previous literature. Pearson’s correlation coefficients for scatter fraction and scatter to primary ratio were 0.983 and 0.981, respectively. The strong correlation between simulation and experiment results indicated correctness in methodology and protocol. The algorithms and protocols in the simulation would be appropriate for designing grids with enhanced scatter rejection capabilities. Keywords: FLUKA code, Monte Carlo simulation, Scatter suppression algorithm, Scatter correction, X-ray imaging systems.