![]() ![]() The diffusion tensor imaging ( DTI) component of the NIH MRI study of normal brain development (Peds DTI). By comparison, the high resolution and the FA with high contrast of gray matter and white matter derived from sequence D (b=800 s/mm2, spatial resolution=1.0 mmÃ-1.0 mm Ã-1.0 mm, numbers of direction=33, NSA=3) qualified in its application in tracking both thick and thin fibers, making it an optimal DTI setting for rhesus macaques. The fractional anisotropy (FA) derived from sequence C (b=1 000s/mm2, spatial resolution=0.55 mmÃ-0.55 mmÃ-2.5 mm, direction number=33, NSA=3) was too fuzzy to be used in tracking white matter fibers. In this study, we analyzed diffusion tensor imaging ( DTI) results of brain white matter in rhesus macaques (Macaca mulatta) with four different parameter settings and found that the sequence A (b=1 000 s/mm2, spatial resolution=1.25 mmÃ-1.25 mmÃ- 1.25 mm, numbers of direction=33, NSA=3) and B (b=800 s/mm2, spatial resolution=1.25 mmÃ-1.25 mmÃ-1.25 mm, numbers of direction=33, NSA=3) could accurately track coarse fibers. MO, Yin CHAO, Fang SONG, Ming LIU, Ci-Rong LIU, Hui-Lang QIAN, Xi-Ying ZHAO, Xu-Dong Parameter comparison of white matter diffusion tensor imaging ( DTI) in rhesus macaques (Macaca mulatta) Although technological advances are necessary to enable the robust and routine measurement of this electrical activity-dependent movement of water molecules perpendicular to axons, the proposed model of d DTI defines the vectorial parameters that will need to be measured to bring this much needed technique to fruition. Specifically, the proposed model, termed “ionic DTI modelâ€, was formulated as follows.•First, based on theoretical calculations, we calculated the molecular water flow accompanying the ionic flow perpendicular to the principal axis of fiber tracts produced by electrical conduction along excited myelinated and non-myelinated axons.•Based on the changes in molecular water flow we estimated the signal changes as well as the changes in fractional anisotropy of axonal tracts while performing a functional task.•The variation of fractional anisotropy in axonal tracts could allow mapping the active fiber tracts during a functional task. The potential changes in water mobility accompanying the movement of ions during the propagation of action potentials along axonal tracts are taken into account. It is termed dynamic diffusion tensor imaging (d DTI) and is based on a hypothesized “anisotropy reduction due to axonal excitation†(“AREXâ€). Here, a modification of the DTI method is presented to enable the mapping of active fibers. Measurements of water molecule diffusion along fiber tracts in CNS by diffusion tensor imaging ( DTI) provides a static map of neural connections between brain centers, but does not capture the electrical activity along axons for these fiber tracts. If you do not want to do this, the clinic can usually do it for you without naming you.The ionic DTI model (i DTI) of dynamic diffusion tensor imaging (d DTI) If tests show you have an STI, you should tell your sexual partner and any ex-partners so they can get tested and treated as well. Some clinics offer home testing kits for some STIs. will tell you what tests they think you need. ![]() may ask to look at your genitals or anus.will ask you some questions about your sex life.You can ask to see a female or male doctor or nurse if you wish.Īt a sexual health clinic, a doctor or nurse: No information about your visit to the clinic will be shared with the GP or anyone else outside the clinic unless you ask for it to be. You do not need to give your real name or tell staff who the GP is if you do not want to. You can feel comfortable sharing information about your sexual activities or orientation with a doctor. You'll often get test results quicker than from the GP and you may not have to pay a prescription fee for treatment. You can usually turn up without an appointment. Sexual health clinics treat problems with the genitals and urine system. You can see a GP, but they'll probably refer you to a sexual health clinic if they think you may have an STI. The only way to know for sure is to get tested.įind a sexual health clinic Why you should go to a sexual health clinic Many STIs have no symptoms at all, like HIV. you're pregnant with symptoms of an STI.you're worried after having sex without a condom.a sexual partner has symptoms of an STI. ![]()
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