Thoracic Pathologies and Radiation Problems
The scanner is the reference diagnostic tool for thoracic pathology. Unlike a standard X-ray, sectional images help to avoid the appearance of shadows. Thanks to the air in the lungs and the contrast media, the resolution is ideal for lung parenchyma examination. In addition, the thoracic scanner has a very high spatial resolution, exceeding the performance of the MRI as part of a health check.
Fast and easy to perform (4 to 5 seconds), CT scan significantly reduces movement artifacts. In addition, the various filters, the software and the 3D reconstructions make it possible to improve the interpretation of the images obtained. Unfortunately, the CT scan shows a very high level of radiation. The low dose chest scanner has been developed to work around this problem.
MAJOR ADVANTAGES OF THE TECHNIQUE
With the low-dose chest CT scan, the primary goal is to obtain usable images with a radiation level equivalent to that of a standard X-ray. The dose is then adjusted according to the age and body size of the subject. The examination thus displays a radiation rate in the order of 1/10th to 1/20th of the 25th percentile of the reference level. Set by the ASCN (Nuclear Safety Authority), this value corresponds to the average dose used in hospitals.
At its lowest level, the low-dose chest CT scan by the best CT scan Centre in Delhi provides satisfactory images for nodule observation or monitoring of problems such as pleural effusion, pneumothorax, pneumonia, etc. With a slightly increased dose, it can serve as a first-line examination for the management of certain diseases. The examination has been particularly successful in the early diagnosis of bronchial cancer in the context of the National Lung Cancer Screening Trial (NLST).
The lung scan may be useful for detecting blood clots in the lungs (pulmonary embolism), but it has largely been replaced by CT angiography in the diagnosis of this condition. Pulmonary scintigraphy can also be used as a preoperative assessment in people with lung cancer. Pulmonary scintigraphy uses small amounts of a half-life radioactive substance to measure air and blood flow throughout the lungs. In general, the exam is done in two stages.
In the first step (pulmonary perfusion scintigraphy), a radioactive substance is injected into a vein, and the scanner produces an image of the diffusion of this product into the pulmonary bloodstream. If perfusion scintigraphy reveals abnormalities, it is necessary to proceed to a second step (pulmonary ventilation scintigraphy).
INDICATIONS AND DISADVANTAGES
The low-dose chest CT scan is particularly interesting because of the quality of the images obtained, its speed and the significant reduction of radiation risks. The technique is mainly used for the early detection of bronchial cancer in a population at risk and the follow-up of various thoracic disorders. Thus, doctors can quickly adjust the treatment of patients, case by case. However, computed tomography poses a significant problem because of CT scan price in Delhi.
Currently, low dose CT screening for lung cancer is four times more expensive than for breast cancer and ten times more expensive than for colon cancer. As a result, it is currently inconceivable to use it for repeated checks. The latter can indeed take several years and generate excessive expenditure for patients and care organizations.