166,660 research outputs found
Radiology
Radiology is the fastest developing field of medicine and these unprecedented advances have been mainly due to improving computer technology. Digital imaging is a technology whereby images are acquired in a computer format, so that they can be easily stored and recalled for display on any computer workstation. Digital image acquisition has been used in ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) from the start. The use of digital imaging in conventional X-rays, known as Computed Radiography, has only recently become possible. Supercomputers now provide the speed required to rapidly process digital image data, while terabyte level storage media allow digital archiving of both radiological images and data. Ultrasound, CT and MRI have also improved immensely as a result of faster computing, which allows shorter exam times, higher image resolution with improved quality and new exam techniques including large field and realtime imaging, noninvasive angiography and dynamic motion studies. Other recent advances in radiology include new contrast agents, Positron Emission Tomography (PET) scanning and novel interventional techniques.peer-reviewe
Diagnostics Of Supernumerary Teeth In Orthodontic Relapse
Aim: increasing the effectiveness of diagnosis and further orthodontic-surgical treatment of various clinical forms of hyperdontia (supernumerary teeth) and preventing recurrence with the use of cone-ray computer tomography data in orthodontic practice.Materials and methods. The clinical case of patient (born in 2004) treatment is presented, with severe hyperdontia and retention of teeth that had little effect on the formation of the general configuration of occlusion. The patient's examination and treatment was carried out with the assistance of clinical, anthropometric and radiological data. The clinical method was to examine the patient and formulate a plan for further orthodontic therapy. The radiological method consisted of data analysis of cefalometry by Bjork, Steiner using a computer program and conducting a survey using a cone-ray computer tomography, followed by the use of these data in diagnosis and orthodontic treatment.Results. Following the clinical and radiological methods of examination and subsequent orthodontic surgery, the corresponding end results were obtained:1. The localization and topography of supernumerary teeth as the causes of relapse of pathology with the help of data obtained with the help of CBCT.2. Radiographic picture reflected on the sagital and axial re-formats of tomograms for the diagnosis of supernumerary teeth, is more informative than diagnostics by standard diagnostic protocols.3. After analysis of the study data, a more meaningful protocol of surgical intervention is prescribed.4. Implementation of the results of modern diagnostics significantly influenced on the final result of orthodontic treatment.Conclusions. Thus, in the process of corresponding work installed:– the availability of computer tomography data is crucial for objective and qualitative diagnosis and treatment of hypertension.– the general level of diagnostics during the intervention is significantly increased
Use of Quantum Sampling to Calculate Mean Values of Observables and Partition Function of a Quantum System
We describe an algorithm for using a quantum computer to calculate mean
values of observables and the partition function of a quantum system. Our
algorithm includes two sub-algorithms. The first sub-algorithm is for
calculating, with polynomial efficiency, certain diagonal matrix elements of an
observable. This sub-algorithm is performed on a quantum computer, using
quantum phase estimation and tomography. The second sub-algorithm is for
sampling a probability distribution. This sub-algorithm is not polynomially
efficient. It can be performed either on a classical or a quantum computer, but
a quantum computer can perform it quadratically faster.Comment: V1-12 pages(5 files: 1.tex, 3 .sty, 1 .eps);V2-minor changes;V3-minor
changes and extension of scenario(c
Realization of quantum process tomography in NMR
Quantum process tomography is a procedure by which the unknown dynamical
evolution of an open quantum system can be fully experimentally characterized.
We demonstrate explicitly how this procedure can be implemented with a nuclear
magnetic resonance quantum computer. This allows us to measure the fidelity of
a controlled-not logic gate and to experimentally investigate the error model
for our computer. Based on the latter analysis, we test an important assumption
underlying nearly all models of quantum error correction, the independence of
errors on different qubits.Comment: 8 pages, 7 EPS figures, REVTe
- …