CT Scan Detectors: Get To Know Its Evolution

The emergence of advanced and sophisticated medical devices have been helping people to get diagnosed of their health issues and to derive proper and complete treatment, so as to lead a disease-free life. One such medical equipment that is gaining immense popularity in the medical field is the CT Scan.

About CT Scanners

This medical device has been designed for the purpose of taking images of the body’s internal structures. This way, it becomes much easier for the medical personnel to avail detailed anatomical information. This is achieved by using the principle of scanning different tissue structure types that get displayed within the image as different grey shades. Also can be used oral contrast media or intravenous to enhance further differentiation between the tissues. The ct scan in Bangalore does offer the best imaging results, making it easy for doctors to diagnose the issue effortlessly.

The CT Scanner’s basic components comprise of a flat panel or an arc banana detector and x-ray tube. It is mounted upon a gantry having a circular aperture. The arc detectors can be found in several rows along a patient long axis, thereby deriving the term ‘multi-slice CT’ or ‘’multidetector CT’. The current patient coverage extent ranges from 12-160mm, which depends upon CT scan model.

Evolving technology

In recent years, CT Scan technology is said to have advanced rapidly, thereby becoming more stable and efficient in its results as well as being more refined data acquisition and engineering systems.

CT Scanner developments are directed mostly towards quicker scanning of the patient lengths by using more fine slices. Hence, this technology has only managed to evolve into volumetric imaging modality from the slice by slice type of diagnostic imaging system. Now, it is possible to reconstruct images in any plane. Also, there will not be noticed image quality loss, thus leading to enhanced usage of 3D display and multi-planar modes in diagnosis.

It is equally necessary to understand that CT Scanner performance in practice depends upon the trade-off between radiation dosage and image quality. Hence, each system is to be evaluated with regards to clinical performance and by observing very closely the used radiation dosage.

Patient volume around 20-40mm in length/rotation is covered by multi-slice scanners. Patient volumes to about 160mm/rotation can be scanned by the advanced multi-slice diagnostic CT scanner.

About CT Scanner detector

The CT scanner’s detector array length is what actually determines the rotation numbers required to cover total scan length, as well as overall scan time. Scanning ability of any given length of few rotations can also help to reduce x-ray tube’s head load, thus allowing long length scanning.

The CT scanner’s detector arrays have been divided broadly into two types, namely:

  • Fixed arrays: The come with equal z-axis dimension detector over a full array extent.
  • Variable arrays: Central portion constitutes the finer detectors. Total scan time in this type for a given length of fine slice acquisition is found to be much longer since there is reduced z-axis coverage. CT Scanners are much greater when compared to fixed array 64 slice acquisitions.

Getting full coverage for an organ does provide benefits for both cardiac and dynamic perfusion studies. The current type of 64 slice scanners having z axis detector array length of around 40mm is found to require few rotations only to cover the organs. Usually, 160mm coverage length allows full organ coverage within a single rotation. Hence, it becomes possible to monitor whole organs with time.

CT Scanner design evolution has been reflecting different strategies so as to accommodate production costs and future developments. Small dosage savings can also be noticed where there are used large detector elements on low slice category scanners.

CT scanners have the ability to provide spatial resolution to the object image without causing blurs. Often, it has been described as image sharpness and quoted as a small object that can be distinguished and evaluated by usage of high contrast test objects, especially where there is a high signal to noise level. Also, perception is not influenced.

The modern CT scanners are to have the ability to achieve isotropic resolution, which is z-axis resolution, approaching or equal to scan plane resolution. This is crucial for 3D, multi-planar and good quality reconstructions.

High spatial resolution CT scanners are of high cost due to its high patient radiation dosage when there is raised tube current for reducing image noise or in high image noise. CT Scanner contrast resolution is actually the capability to resolve any object from the immediate surroundings. At times, this is also termed as low contrast detectability. It is the contrast, size and image noise level that determines the ability to identify an object. Usually, contrast resolution is specified as the object’s minimum size of a given contrast difference, which could be resolved for any specific scan set. Also, the CT scanners’ temporal resolution is said to be defined as time consumed for acquiring a data segment for the purpose of image reconstruction.

Temporal resolution in CT scanners is regarded within cardiac scanning context. Cardiac CT’s objective is to reduce image artifacts caused by the heart’s constant motion. ECG gating techniques can be used along with heart imaging during cardiac cycle’s least movement to achieve this objective. This, in turn, causes short periods of temporal resolution requirements, when compared to heart cycle. For every given heart rate, there is the present optimum combination of segment numbers, gantry rotation time and pitch.

Radiation beam emerging from the patient is captured by the CT scanner detectors and converted to electrical signals, whereby they are converted subsequently to binary code information to be transmitted for further processing to the computer system.

Also, the scanner detectors are to have the ability to respond with extreme speed to the signal, discard quickly the signal, and prepare for next without a lag. Moreover, they are to consistently respond and be small with regards to size. They also should come with high absorption efficiency, high capture efficiency and conversion efficiency, combined together and termed as detector dose efficiency.

Overall, the top ct scan centers in Bangalore do offer the very best diagnosing and treatments to those suffering from health issues.


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