A CT scan works in such a way that the patient or the person being scanned sets themselves on a table facing upwards. The table on which the person lies is then passed through the middle region of the x-ray machine. The process may also require the patient to hold his/her breadth to ensure minimal blurring of pictures. Often, a contrast agent may be added into the blood veins either by injection or ingestion, some minutes before the CT scan. The purpose of the contrast die is to cause specific tissues of the body to become more visible to the operator. It must be noted here that the CT scans do not cause any form of pain to the patient apart from some discomfort caused by lying in one position during the entire process.
CT scan information can be used to make models in three ways. The approaches include the use of CAD system, the use of STL-interfacing and direct interfacing. It is worth noting that CT scans have a good advantage over other forms of scans. This is because the data sourced from a CT scan can be used to produce human body structures by the rapid prototyping systems. The way in which the scans enable tissue separations is also advantageous in that it becomes useful for assessing soft tissue lesions around the pelvis. CT studies can also be combined with contrast materials for special evaluation such as CT myelography. Images can therefore be obtained in the transverse plane and thereafter reconstructed by computer with the frontal and suggital planes or presented as 3-D images for a more graphic display (Staheli, L. 31).
However, this technology also has its own shortcomings. For instance, infants and the young children need sedation. This is to prevent them from absorbing the negative effects of the scans. CT scans also have a greater radiation exposure (Meercola 4). It is also worth noting that the scans expensive in comparison with the conventional studies. The other disadvantage is that the data sourced from CT scans is much difficult to deal with. The interpretation of the images and the data is also very difficult. This means that a special interpreter is needed to perform a complete CT scan. This is one of the reasons why the operation is pretty expensive. There is also the risk of allergic reactions or contrast nephropathy. Other situations can also occur whereby the patient who has undergone a complete CT scan experiences short breadth. Worse still, other people who have undergone this scan may experience throat swellings.
CT refers to computerized topography scan. The scans show structures within the body created by a computer. The computer takes data from multiple x-ray images and presents them on a screen as pictures. The scan generates data as a grid of three dimensional points, where each point has a varying shade of grey that indicate the density of the body tissue which are found in that particular place. It is important to note that the technology has helped in the collection of data which have been used to build skull, femur, knee, and other bone models on stereolithography systems. Some of these reproductions have been used to generate implants, which have been successfully installed in patients. The data actually consists of raster images of the physical objects being scanned. Even human temporal bones have been produced using these scans. CT studies therefore provide excellent bone and soft tissue details. The soft tissues can also be manipulated by computer to enhance tissue separations.
It is also important to look at the flip side of the disadvantages. Thus, while it may be disadvantageous for a patient to undergo a complete CT scan, the effects of not doing a complete CT scan must also be considered. Not having the procedure can be more risky than having the procedure. This is why people who want to undergo the procedure must do an extensive research on the pros and cons of the process since the process has different effects to every patient depending on the level and nature of illness.
There is also another kind of CT scan called a spiral CT. Here, the machine rotates around the body in a continuous cycle along a spiral path. This results into a cross section of the pictures of the body. The spiral scan comes with a number of benefits. The scan can be used to make three dimensional pictures of body organs that are situated inside the body. Due to its circular movement, the scan can detect small areas that have some kind of abnormalities. Last but not least, the procedure is faster than the conventional CT scan thereby reducing the discomfort caused by lying on one area for a long time. Other kinds of scans include the virtual endoscopy and a combined PET/CT scanning. These techniques are newer and allow for better imaging, and they also mitigate the negative effects of CT scans.
Works Cited
Mercola. The Dangers of CT Scana: How CT Stands for Cancer Trap. Web.
Staheli, Lynn. Fundamentals of Pediatric orthopedics. Lippincott Williams & Wilkins, Philadelphia, 2008.