The amount of radiation dose a patient receives from a ct scan depends upon two key factors, the design of the scanner and also on the way that the scanner is used. Though there are benefits as well as limitations of the multislice ct scanner but it has helped the radiologist to view the bones, organs and blood. Multidetector computed tomography mdct is a form of computed tomography ct technology for diagnostic imaging. Multislice spiral computed tomography msct coronary angiography is a promising noninvasive technique for the detection of coronary stenoses. The first to see radiographs, however, were not physicians.
Objectives the aim of this study was to assess the value of multislice computed tomography ct for the assessment of valvular abnormalities in patients with infective endocarditis ie in comparison with transesophageal echocardiography tee and intraoperative findings. Pdf radiation exposure in multislice versus singleslice spiral ct. The word tomography is derived from the greek tome slice and graphein to write. Each of the 16 detector rows could, in principle, simultaneously collect data for 16 slices, each 1. Jul 28, 2010 then, around the end of the millennium, the multislice or otherwise called multidetector ct scanners came into use1012.
Ct scan synonyms, ct scan pronunciation, ct scan translation, english dictionary definition of ct scan. Multislice ct free download as powerpoint presentation. Characteristics of multislice ct exceeding 1 meter during single breath holding fig. After the introduction of singleslice spiral ct ssct into clinical practice in 1989 1, the next considerable advance was the development of multislice spiral ct msct systems. Noninvasive evaluation of the aortic root with multislice computed tomography. At the same time, the scanning time of msct can be reduced by up to onetenth that of single slice ct when an image with the same scanning range is required. Ct scan of the neck for a possible tumor of the nasopharynx will require slice thickness of no greater than. Then, around the end of the millennium, the multislice or otherwise called multidetector ct scanners came into use1012. Oct, 2017 single slice the origin of the word tomography is from the greek word tomos meaning slice or section and graphe. Ct was invented in 1972 by british engineer godfrey hounsfield of emi laboratories, england. Emphasis on hemodynamic changes and imaging pitfalls.
Multiple slice ct scanners, first introduced in 1998, could take 4 separate images in each rotation. More complex than a traditional xray, which uses a stationary machine to focus on a particular body part, ct scans use an xray generating device that rotates around the. Scanning methods digital projection ap, pa, lat or oblique projection surview, scanogram conventional ct axial startstop volumetric ct helical or spiral ct continuous acquisition. Like traditional xrays, it produces multiple images or pictures of the inside of the body. A detector design used in one of the first modern msct scanners fig. A table speed b patient dose c slice thickness d noise level chapter twelve. The gantry should have a minimum tilt of 30 degrees on either side and remote tilt should be available as standard. Bax percutaneous replacement of the aortic valve is.
Imagine that you took a long strong sword and cleanly separated the top from the bottom. The scan time for a 360 degree rotation should be less than a second 7. As the patient passes through the ct imaging system, a source of x rays rotates around the inside of the c. The latest advance has been the recent introduction of multislice ct msct scanners. Computed tomography definition of computed tomography by. X rays are a form of high energy radiation and are themselves, able to cause cancer. A ct scanner uses an xray beam that revolves around a patient to produce a cross sectional image known as a slice. The ct scanner sends xrays through the body area being studied. This article is a revised english version of a paper originally published in the journal of the japan. This greek word comes from two distinct words tomos and graphe.
The difference in appearance between these two results from their makeup. Tomos means section or slice while graphe means drawing. The underlying idea is the following simple observation. Single slice the origin of the word tomography is from the greek word tomos meaning slice or section and graphe meaning drawing. Understanding the difference between a single slice ct and a. During the test, you will lie on a table that is attached to the ct scanner, which is a large doughnutshaped machine. Within the last several years, spiral computed tomography angiography scta of the pulmonary arteries has emerged as a noninvasive angiographic modality for the evaluation of patients with suspected pulmonary embolism pe.
This has improved the diagnostic capabilities of ct. Radiation exposure in multislice versus singleslice spiral. Patient dose considerations in computed tomography examinations. The cancer risk increase with accumulating radiation from many exams and also age of patients. The eclectic story of medical imaging began, of course, much earlier, when wilhelm rontgen discovered the xray. Since then, technology has improved and now, the ct scanners can take between 6 and 16 separate images in a single rotation.
Mri offers the advantage of lack of radiation exposure, although it is more expensive. Spiral computed tomography of pulmonary embolism european. Multislice computed tomography in infective endocarditis. Rontgen, a physicist, introduced them in january 1896 at the 50year anniversary meeting of the society of physics. The cns can be divided by appearance into white matter and gray matter, which can be differentiated by ct. In other words the isotropic 3dimensional voxel could not. Ct scan definition and meaning collins english dictionary. The doses of x rays used in ct scans are as low as possible, but they do present some risk of doing harm. Jun 03, 2014 ct ct computed tomography cat scan computerized axial tomography 632014 hareesha n g, dept of aero engg, dsce 14. With the advent of multislice or multidetector technology, computed tomography ct is now a routine diagnostic imaging modality that is versatile and reliably answers many referring doctors clinical questions. We divided the human body into 11 cylindrical parts head, forearm, upper arm, chest, abdomen, thigh, calf for the measurement. Ct was invented in 1972 by british engineer godfrey hounsfield of emi. Whats difference between single slice ct and multislice ct.
Multislice ct scans have an advantage over single slice ct scans. Ambulances equipped with small bore multislice ct scanners respond to cases involving stroke. Hounsfield units hu ct numbers arbitrary scale based on attenuation with water assigned a ct number of 0 one ct number hu 1 of water attenuation value 0. The crosssectional images generated during a ct scan can be reformatted in multiple planes. Patient dose considerations in computed tomography. Air may be injected into the joint for a ct scan of synovial joints. Computed tomography ct multi slice ct scan with the advent of multislice or multidetector technology, computed tomography ct is now a routine diagnostic imaging modality that is versatile and reliably answers many referring doctors clinical questions.
Proposed method is simple, fast, accurate and completely automatic. Patients and methods from september 20 to may 2014, 40 patients complaining from unstable angina showing initial negative ecg and troponin enzyme underwent a multislice ct coronary angiography. Pdf multislice ct scans in patients on extracorporeal. New applications with the assistance of innovative. Ct ct computed tomography cat scan computerized axial tomography 632014 hareesha n g, dept of aero engg, dsce 14. Segmented multiple plane reconstruction a novel approximate. It is a greatly advanced technology which has made possible the visualisation of the diseases accurately and at a faster pace. In 1983, our group introduced a new method for fat analysis using a computed tomography ct scan, which allowed the separate measurement of subcutaneous fat and intraabdominal visceral fat.
At the rsna 1998, this new technology was introduced by several manu. An automatic method for complete brain matter segmentation. Dec 21, 2018 home medterms medical dictionary az list multislice ct definition medical definition of multislice ct medical author. Difference between single slice and multi slice ct scanner. This first article covers the fundamental principles of ct, including the basic geometry of the ct scan process, the nature of the measurements made by ct detectors, a qualitative explanation of the image reconstruction process, the evolution of ct technology the 4 generations of ct from the emi firstgeneration scanner through modern slip. The beam is collimated with a prepatient collimator to fall on the entire detector array, the beam width is defined in the zaxis at the center of rotation but now is a fourrow ms detector array, the width will be 4 slices and is prescribed by the precollimator, so if a precollimator widith of 8mm falls on a 4 row detector, array each slice will have a thickness of 2 mm, the four slices.
All msct facilities were requested to provide information about 14 standard examinations with respect to scan parameters and frequency. The ct scanner should have low voltage slip rings incorporated in the gantry 6. Crosssections are reconstructed from measurements of attenuation coefficients of xray beams in the volume of the object studied. Computed tomography ct scanning, also known as, especially in the older literature and textbooks, computerized axial tomography cat scanning, is a diagnostic imaging procedure that uses xrays to build crosssectional images slices of the body. Crosssectional anatomy can be reconstructed in several planes without exposing the. Whats difference between single slice ct and multislice. Multislice ct scanner has revolutionised the entire field of medicine. Noninvasive evaluation of the aortic root with multislice. The mri findings significantly correlate with those of a ct scan. A tomogram intends to visualize a very thin piece of tissue.
Describe this difference by indicating what gray matter consists of. Implications for transcatheter aortic valve replacement laurens f. Computed axial tomography ct scans or cat scans use x rays to create images of body tissues. A ct scan and magnetic resonance imaging mri at the umbilical level are the standard techniques used for the assessment of visceral fat accumulation 612. Jan 17, 2020 the t in ct means tomogram or tomography. From a given multislice ct dataset, one slice is selected automatically to form masks for segmentation. Multi slice ct in 1998, several manufacturers introduced multislice ct msct. Scta is based on continuous computed tomography ct data acquisition during patient transport through the rotating x. To evaluate the different patterns of coronary artery disease among patients with unstable angina by the role of multislice ct coronary angiography. Multislice computed tomography scan with 3d reconstruction can be really helpful in diagnosing the elongated styloid processes and their. These scanners, called multislice ct or multidetector ct, allow thinner slices to be obtained in a shorter period of time, resulting in more detail and additional view capabilities. A computed tomography ct scan uses xrays to make detailed pictures of structures inside of the body. Multislice ct scans in patients on extracorporeal membrane oxygenation.
Modern ct scanners are so fast that they can scan through large sections of the body in just a few seconds. In reconstruction tomography ct and pet the image is produced by a. Computed tomography, more commonly known as a ct or cat scan, is a diagnostic medical imaging test. Ct scan definition of ct scan by the free dictionary.
Another characteristic of msct is its excellent zaxis resolution. With the latest multislice ct msct scanners, a whole body examination can be performed in less than 5 min, with most of the time spent in patient positioning rather than the actual scanning procedure, which lasts less. Role of multislice ct coronary angiography in evaluating. The eclectic history of medical imaging imaging technology news. Multislice ct scanner mercy gilbert medical center. Yet, repeat of ct scan produce additional effective dose accumulate in the body. In a scanner, the radiation sensors convert xray photons to. Background multislice ct has recently shown promising data regarding valvular imaging in a 4dimensional fashion. Basic principles of ct scanning linkedin slideshare. A ct scan, or computed tomography scan is a medical imaging procedure that uses. Bax percutaneous replacement of the aortic valve is evolving as a.
In conventional radiology, tomographic images body section radiographs are produced by motion of the xray tube and film or by motion of the patient that blurs the image except in a single plane. Clinical significance of visceral adiposity assessed by. Understanding the difference between a single slice ct and. A ct scan, or computed tomography scan formerly computerized axial tomography scan, or cat scan is a medical imaging procedure that uses computerprocessed combinations of many xray measurements taken from different angles to produce crosssectional tomographic images virtual slices of specific areas of a scanned object, allowing the user to see inside the object without cutting. Conventional tomography definition of conventional. Apr 28, 2017 ct scan the meaning of the word tomography. Radiation exposure in multislice versus singleslice. The overall geometric efficiency is subdivided into two aspects.