Every part of the body may be examined with Computer Tomography or CT. The chest CT scan is useful, for instance, as a screening tool for early discovery of tumors in patients that are symptom free. CT 3D scans of the face and mandibles are helpful to surgeons in planning tooth implants.
Computer Tomography Screening
While, in the beginning of the Twentieth Century, lung screening was introduced with great effectiveness for the purpose of eliminating TBC, today, it is lung cancer that has made it a necessity, especially, since it is lung cancer that claims the most victims not only in Hungary, but also in the world as a whole, men and women equally. The high death rate can be attributed not only to the environmental impact, smoking and smog, but also, to the lack of timely screening and early diagnoses. Yet, of all the cancers, lung cancer is one of the most preventable.
Eighty-five to eighty-seven percent of lung cancers can be connected to active smoking, while 3-5% to passive smoking. The more an individual smokes, the higher the risk of eventual lung cancer. It has been shown that, smoking a cigarette pack per day increases the risk of lung cancer ten-fold in men, five-fold in women. Lung cancer has become one of the most important health problems from the standpoint of research and prevention.
The chest x-ray provides a so-called summary exposure wherein the images of the entire thickness of the body are projected together. Computer Tomography, on the other hand, prepares images perpendicular to the axis of the body and a few millimeters in thickness. The resulting images are not projected together and, thus, allowing for even minute details to be observed. The state-of-the-art, so-called multislice CT (MSCT) scan is capable of even higher resolution with low radiation making detailed sequences of the chest (lungs, heart, ribs, etc.) possible. The digital images may be stored to be retrieved sometime in the future, making the examination of the lungs, the heart and the bony frame of the chest at a later date possible with the help of various reconstruction and 3D software techniques.
Conventional x-ray already allows for an increase in the number of lung cancer cases diagnosed. The added advantage of the MSCT is in identifying abnormalities of only a few millimeters, are located in such areas as behind the heart or near the diaphragm, or in such areas of the lung that make identification difficult.
The MSCT scan uses very low radiation doses.
Computer tomography is excellent in diagnosing lung diseases other than tumors.
Yearly examinations are recommended.
Computer Tomography in Dentistry
The special CT scan is very helpful to dentists and oral surgeons in planning tooth implants. The bony structures of the maxilla and the mandibula may be shown and evaluated along with the roots and the tooth sockets (arcus alveolaris, processus alveolaris, alveoli dentales, n. alveolaris inferior), making it possible to determine, with great accuracy, the position and size of the implant and planning the exact implant and prosthesis needed.
The examinations follow prescribed protocols and take only 15-20 minutes:
- A scout scan (referential imaging) is prepared from the mandibula angle to the temporo-mandibular joint.
- Every 1 mm paces, 1.3 mm images are prepared in the region marked.
- FOV: 200 mm.
- Sagittal, coronal, transversal (axial) plane images.
- The root of the tooth is part of the examination - images aimed at tooth sockets for reconstruction.
- 3D reconstruction is available along with Panorex in order to determine the following most important anatomical characteristics of the mandibula:
- the contours of the alveola,
- the height of the alveola,
- the condition of the inferior alveolar nerve.
The Patient will receive a CD of the CT images.
Virtual colonoscopy is a new method devised for the examination of colorectal diseases wherein the colon is first filled with air, computer tomography images are then prepared of the abdomen in order to view the inner surface of the colon without the necessity of mirroring or barium enemas.
When should this method be used?
The method is excellent in identifying colorectal polyps and tumors in screening examinations for asymptomatic patients or for patients with complaints suggesting colorectal polyps or tumors.
Advantages over other types of colorectal examinations
When filled with air, the entire length of the inner surface of the colon is visible with the help of a special computer software. The thickness of the entire inner wall may be examined, noting abnormalities and changes in the surrounding areas. The examination is not painful, does not cause any discomfort and is significantly better tolerated than mirroring.
The colon may also be examined with the irrigoscopy method. This is an x-ray technique that requires a barium enema and air that is pumped in through a tube. With this method, however, only the silhouette of the colon may be seen and not allowing for seeing beyond the wall.
What preparations are necessary?
The day before the examination, the patient may only drink fluids and a special laxative. The day of the examination, no eating or drinking is allowed. It is important that these instructions be followed, since the success of the examination depends on the extent to which the colon is cleansed.
The examination procedure
The examination is performed in the computer tomography room in the radiology department, usually in the morning hours, to keep you from having to go hungry for too long.
The procedure takes about 20-30 minutes and does not require sedation. You will be asked to first lie face up on a table. A thin tube will be inserted through the anus and into the rectum through which air will be pumped to fill the large intestine. The table will move through the CT scanner producing a series of cross-sectional images of the colon. The procedure will be repeated while the patient lies face down. In some cases, contrast material may be necessary (administered through the vein) to more precisely determine the condition of the intestinal wall, find any abnormalities and observe the surrounding areas. The radiologist will evaluate the results that should be ready by the following day. The patient will receive a CD of the images.