In this paper, an improved back-projection algorithm of dynamic electrical impedance tomography (EIT) was described. The improved back-projection algorithm modified the computing method of back-projection matrix B. Dynamic reconstruction image was obtained by the improved algorithm, and it was compared to the image obtained by the traditional method of equi-potential back-projection. The results showed that the improved algorithm of equi-potential back-projection could locate the object's position in the field with higher precision, and its speed was very fast. It also could improve the resolution of the reconstructed image in some extent.
Algorithms ; Diagnostic Imaging ; methods ; Electric Impedance ; Humans ; Image Processing, Computer-Assisted ; methods ; Models, Biological ; Tomography ; methods

HIV (human immunodeficiency virus) is an increasing concern in the South Pacific. We estimate, based on reported figures, that the prevalence of HIV infection in women attending antenatal clinics in Fiji in 2003 was 0.04%. The number of children born to HIV-positive mothers is small, though perinatal transmission appears to be high. Fiji's preliminary strategies for prevention of perinatal transmission have been significant, but require ongoing support and implementation.
Fiji ; Prevalence aspects ; Human Females ; HIV Infections ; HIV

Objective: Multiple system atrophy (MSA) is characterized by urinary dysfunction, yet the influence of sex and gender on urinary symptoms and treatment is unclear. We sought to characterize sex and gender differences in the symptomatology, evaluation, and management of urinary dysfunction in patients with MSA. Methods: Patients with MSA evaluated at our institution were reviewed and stratified by sex. Results: While the prevalence of urinary symptoms was similar in male and female patients, incontinence was more common in females. Despite this, males and females underwent postvoid residual (PVR) measurement at similar rates. While catheterization rates were similar when PVR was measured, males were more than twice as likely to be catheterized than females in the absence of PVR measurement. Conclusion Urinary symptoms are common in MSA, but their presentation differs between males and females. The difference in catheterization rates may be driven by a gender disparity in referrals for PVR, which can guide treatment.