Providing a clearer spatial perception than conventional CT scanning is certainly one of the greatest advantages of Helicoid Computed Tomography . This is achieved because, in it, the images are obtained from cross-sections of the body which avoids the overlapping view of the structures.
Even the different tissues can be differentiated and identified by Computed Tomography since it allows to distinguish different densities with a greater degree of precision. While in the conventional radiology the threshold of distinction is in the house of the 5%, in the Computed tomography one can distinguish variations in the order of 0.5%.
The great advantage of this greater histological and structural definition is undoubtedly the possibility of detecting anomalies that would be impossible to diagnose without the use of invasive methods.
An important advance in diagnosis has also been achieved, thanks to the development of Computerized Tomography , to obtain diagnostic data in neurology since this instrument allowed the observation of cerebral lesions without invasive needs.
Already Computed Tomography Helical (CT Helical) represents a further technical breakthrough, which allows faster and more accurate images than CT standard.
Helicoidal Computed Tomography allows the image to be imaged and injected simultaneously, so that the images can be acquired during specific phases of contrast enhancement.
The clinical applications of Helical Computed Tomography include all applications of conventional Computed Tomography in the thorax, abdomen and musculoskeletal system, as well as a variety of new applications such as angiotomography and three-dimensional imaging. It is the study of choice in the evaluation of pulmonary pathologies; has numerous applications in the liver, pancreas, kidneys and other abdominal organs; and is of great value in the assessment of trauma and the musculoskeletal system in general.
In helical CT, the patient is moved through the gantry continuously, while the examination is also performed uninterruptedly, so the x-ray beam traverses the patient forming a helix. After the entire anatomical region is examined, the data can be reconstructed into individual sections. The acquisition of a “volume dataset” of the examined anatomical volume allows excellent reconstructions of bi and three-dimensional images.
The great advantage of images that can be combined two-dimensional or three-dimensional (3D), is that they may be guiding adequately the surgical planning and indication of treatment.
Helical CT provides a simple, rapid and less invasive study for the patient. The examination times are between 40 and 80 seconds, with the patient in the device for a maximum of 5 to 10 minutes.
Another important advantage is that CT scans provide images compatible with the actual size of the object (ratio 1: 1). Although it is considered a costly examination, we should always analyze cost-benefit because it becomes cheap when compared to surgical problems and other invasive methods.
With Computed Tomography, we have an advanced image examination that can be used to evaluate anatomical parameters such as amount of bone available in lesions of alveoli or even other bones in need of surgical repair, relation between the cortical and trabecular bone, degree of bone mineralization and degree of accuracy to locate vital anatomical structures and their possible changes.
According to Williams et al. (1992), Computerized Tomography uses X-rays to produce the digital description of an image that can be placed on a computer monitor or in a film. The image can be viewed on the computer screen during mapping or can be photographed and stored on discs or on magnetic tapes. A series of images can also be produced and organized so that it can be photographed on the radiographic film for diagnostic evaluation.
But Tomography also has some drawbacks. The main one is the use of X-rays. This type of radiation has a negative effect on organisms, especially for their ability to cause genetic mutations (more visible in cells that are in the phase of rapid multiplication). Although the risk of developing anomalies is very small, in humans, for example, the use of CT scans is not advisable for pregnant women and children. In veterinary use, it should be avoided during pregnancy.
The radiation dose administered in this type of examination is considered high when compared to conventional techniques, so appropriate criteria should be used to request this procedure, remembering the cost-benefit ratio, since the risk may be acceptable when compared to the number of information obtained.