Question

no google copy and paste required

with respect to medical imaging expalin the following

1. Cardiac CT
2. Dual-energy CT
3. CT scanner generations, construction of modern CT scanner, Electron beam tomography, thomosynthesis, Cone Beam CT scanner
4. CT image quality and artefacts
5. Biologic effects and safety in CT

Answer 1

Explanation:

Cardiac CT – The cardiac CT is also known as computed tomography of the heart. It is a noninvasive and painless method that can analyze the details of the heart’s anatomy along with blood vessels using an imaging test. This technique is used to evaluate cardiac functions, diagnose coronary artery diseases, detect calcium blocks and evaluate the implanted stents and bypass grafts.

Dual-energy CT – Dual energy CT is also termed as spectral CT. It is a computer tomography method which uses two different x-ray photon energy spectra. It detects the reducing energies of two different materials. The dual energy CT scanner is advantageous over the normal CT scanner so that the images are clearly visible with details. The dual energy CT is commonly used for identification of myocardial ischemia, pulmonary embolism, pancreatic diseases and renal stones.

CT scanner generations – There are four generations of CT scanners. Many improvements in the techniques, detectors and scanners are observed as the generations increase. The scanning time is decreased in fourth generation than the first generation. The first generation uses a pencil beam X-ray with a single detector and scans take an average of 30 min. The second generation uses a fan shaped beam X-ray with 30 detectors and scan duration is approximately 90 sec. In the third generation, fan shaped beam X-ray with approximately 700 detectors arranged as an arc that scans within 5 sec. In the fourth generation, a fan shaped X-ray beam that has an average of 2000 detectors which scans within few sec.

Construction of modern CT scanner – The modern CT uses an X-ray or an electron beam. Multiple detectors with appropriate scanners are used so as a clear cross sectional image is seen from various angles. Several organs, lesions in organs, soft tissues, blood vessels, blocks, mineral stones or depositions are easily visible. The advantage of modern CT is the scans are completed fast in fraction of second.

Electron beam tomography – It is form of computed tomography (CT) method. An electron gun is used rather than an X-ray. It is a sensitive rapid method which is commonly used for identification of calcium deposits or blocks in the arteries.

Tomosynthesis – Tomosynthesis is a high resolution digitalized tomography method. It is used in the imaging of dental, musculoskeletal and chest.

Cone Beam CT scanner – It is also known as flat panel CT or cone beam volume CT. It is a digitalized X-ray tomographic technique. It is commonly used in ENT, orthopedics especially during surgeries.

CT image quality and artifacts – Artifacts are commonly used in CT because they can mimic pathology as well as they alter or reduce the image quality. Artifacts in CT are commonly used in clinical CT. Some artifacts that are used are noise, scatter, metal artifacts and motion.

Biologic effects and safety in CT - These scans expose more radiation than other imaging tests. X-ray induces neoplasms through damage and alterations to cellular DNA, and that this risk is related to the dose administered.