Optimization reconstruction techniques

Gain and power settings should be optimized so that all structures of the penis are appreciable. Harmonic imaging and 3D reconstruction techniques can be used, if available, but they are not mandatory for the diagnosis even though they can offer a more detailed image of the small post-cavernosal arteries, which are frequently compromised in subjects with diabetes or systemic arterial disease. 

As the large number of patents in the X-ray collimator field reveals, it is by no means a trivial exercise to design a collimator optimally satisfying the constraints imposed by the above factors. It is unfortunately beyond the scope of this chapter to discuss the science of collimator design ( collimatology ) except that it is customary to group X-ray collimation techniques into two main categories, i.e. direct and reconstructive. These possibilities are summarized in Sections 4.2 and 4.3. 

As stated above, the utility of the ML estimators derives essentially from their asymptotic properties of consistency and optimality (i.e., cov(0ml) — CRB). When the data exhibits significant departures from theoretical pdf (Gaussian or Rice) owing to acquisition artifacts, it may be judicious to use robust non-linear regression techniques,62 as in parametric diffusion-tensor imaging reconstructed from echo-planar data.63... 

One of the difficulties of quantitative imaging is that each of the steps that result in parametric mapping is closely dependent on the context, and especially on the model and the distortions induced by the measurement protocol. To our knowledge, no software package is currently available that will manage all the tasks described in this chapter. As efficient softwares for such optimization and reconstruction becomes more generic and commonly available, such techniques will be certainly applied with increasing frequency and efficiency. 

Fig. 6.1.4 Gradient paths for 3D reconstruction from projections. Only half a hemisphere is covered by the gradient paths, because signal for negative gradient values can be acquired by time inversion in echo techniques, (a) 3D space can be covered by a set of 2D projections, so that the 2D algorithm can be applied in two steps, (b) Optimization of the point density in 3D k space requires an integral approach to 3D reconstruction from projections. Adapted from [Lail] with permission from Institute of Physics.

The reconstruction accuracy of the measurement system depends on the step frequency of the input signals A/ and the load impedance. Clearly, additional study is required to explore the promise of this method including application this method to estimate faults in different wiring and cables with considering of mechanical variations estimation of much more complicated wiring systems identification of the factors affecting the reconstruction accuracy and a detailed estimation and comparison of different optimization techniques. 

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