Gamma cameras are based on the detection of gamma rays emitted from radionuclides. Gamma cameras image the radiation from a tracer introduced into the patients body. The gamma camera is an imaging technique that is used to execute functional scans of brain, thyroid, lungs, liver, gallbladder and kidneys. The applications of scintigraphy include early drug development and nuclear medical imaging to view and analyse images of the human body or the distribution of. Capable of withstanding ray detection rates up to tens to thousands events per second 2. Like light, gamma rays are composed of photons, which behave in some ways like a particle and in other ways like a wave. We are all exposed to radiation naturally background radiation.
The basic design of the most common type of gamma camera used today was developed by an american physicist, hal anger and is therefore sometimes called the anger camera. Imaging and detectors for medical physics lecture 5. The gamma camera is an imaging technique used to carry out functional scans of the brain, thyroid, lungs, liver, gallbladder, kidneys and skeleton. Advantages of gamma camera the scintillation detector detects efficiently bec. The resources consist of six sets of presentations, worksheets and teacher notes that complement the institute of physics 2011 schools lecture from xrays to antimatter. Most studies are performed using 99m tc, which emits a 140kev gamma ray. Feb 27, 2015 im generally on the more clinical side of things, and im not a physicist, but heres my understanding. The gamma camera, also called a scintillation camera, detects radioactive energy that is emitted from the patients body and converts it into an image. Gamma cameras the most widespread of nuclear medical diagnostics. Nucam, a gamma camera based on a lightweight camera head with a detection assembly made of arrays of cdte spectrometers, has been developed and clinically tested. Quality control of scintillation cameras planar and spect michael k.
Subscribe to our newsletter to receive the latest news and events from twi. Xrays do not give any sort of medical data for organs or tissues, only an image of bones. Gamma rays cause some ionisation therefore the patient will be exposed to some radioactivity as well as the nursespatients family. The reason for this burst of activity is the expectation that the semiconductorbased gamma camera would outperform the conventional angertype gamma camera with a large scintillator and. Slides to iaea nuclear medicine physics handbook human health. Images of the thyroid gland obtained using gamma cameras present numerous advantages over those obtained by scanners, in particular for the study of cold nodules, the thyroglossal duct or ectopic thyroids, and generally in every case where iodine uptake is very low.
Using a digital gamma camera journal of nuclear medicine. It helps to diagnose tumours easily without the need of surgery. Gamma knife radiosurgery has many advantages compared with traditional surgery and other types of radiation treatment. Despite the clinical success and wide availability of gamma camera and spect imaging, and its advantages of relatively low cost and capability for imaging two. Once the camera is delivered and installed, verification of the camera specifications constitutes the first quality control test which is performed on the system. A crystal inside the head of a gamma camera scintillates in response to radioactive particles, producing a burst of light that is picked up by sensors located behind the crystal. This principle of measuring coincidences has the advantage that a collimator is not needed. It is designed to provide users of the scintillation cameras with test procedures for performance evaluation. Pdf quality control of gamma camera with spect systems. Gamma camera imaging of radioactive sources in patients three major components.
Scientists measure gamma radiation in their attempts to understand how the universe works. The gamma camera is designed to provide acceptable detection efficiency while maintaining high intrinsic spatial resolution in the energy range of 100200 kev. Feb 05, 2010 in a nuclear reactor the gamma rays being absorbed in the structure produce a lot of thermal stress and the design of the reactor must include thermal shields to reduce this. A new gamma camera at a fraction of the cost drawing on many years of manufacturing experience since 1981, mie have developed a system of remanufacturing to deliver cost effective process is also ce certifed and fda registered. Quality control of scintillation cameras planar and spect. Recent advances in nuclear medicine imaging technology. Gamma camera operation detects rays and for each ray records. List qc tests for gamma cameras required by accrediting organizations. Xray imaging 8th june tutorial week 2 th june lecture. Mri or ct scans are excellent tools if the doctor is trying to find a medical issue with organs, bone, the brain, and tissues. A gamma camera is a perfect device for detecting nuclear fission products from either nuclear detonations or nuclear power plant reactors accidents. Gamma rays are a type of electromagnetic radiation, just like xrays, radio waves and visible light.
Oconnor, mayo clinic, rochester, mn the purpose of quality control qc is to detect changes in the performance of a gamma camera system that may adversely affect the interpretation of clinical studies. In the late 1960s and early 1970s, gamma ray detectors on the vela satellite series recorded bursts of gamma rays from deep space. Gamma rays compared with xrays for radiographic inspection. It consists of a large diameter naitl scintillation crystal which is viewed by a large number of photomultiplier tubes. Scintigraphy scans get their name from the ability of some crystals such as sodium iodide to scintillate in other words, emit sparks when exposed to radiation. As a result, the detection efficiency of the gamma camera detector is somewhat less than would be desirable at higher. Some modern gamma cameras have more than one crystal.
These systems can make images a single slice at a time or. Gamma rays compared with xrays for radiographic inspection twi. As a result, a pet scanner delivers a higher number of impulses and a. Analyzing the advantages and disadvantages of digital cameras. A bit of history the gamma camera gamma, gamma, gamma, gamma, gamma camera uses for the camera of gamma it is also quite accurate due to the tracer the patient takes prior to examination and gives detailed images of the body. These systems can make images a single slice at a time or they may be stacked to produce multiple slices. Imaging and detectors for medical physics dr barbara camanzi barbara. Planar scintigraphy used in nuclear medicine imaging emission imaging radioactive source inside patients body in both spect and planar scintigraphy radiation source used mainly 99 a 140 kev rays hence the name gamma camera. The advantages of imaging using gamma rays include the fact that it is noninvasive, and there are no ethical issues. Neurosurgeons and patients often prefer gamma knife radiosurgery because. Camera characteristics such as 600% dynamic range, nonlinear gamma processing and white balance adjustment would require an ad conversion resolution of approximately. One disadvantage of xrays is that they do not give detailed images of the body. Gamma rays are highfrequency waves emitted by stars and radioactive substances.
Its an outpatient procedure that takes less than a day. Basic physics of nuclear medicinenuclear medicine imaging. Physical principle of imaging with gammarays wikilectures. The advantage of spect is that its like all nuclear medicine techniques it studies physiology. Advantages of digital cameras eliminates film processing. Because the waves can easily pass through most material, avoiding gamma ray exposure requires a shield of lead or concrete. The special camera and imaging techniques used in nuclear medicine include the gamma camera and singlephoton emissioncomputed tomography spect. The amount of radiation you receive depends on the examination being performed. We report the performance characteristic of gamma camera by intrinsic calibration and. Radionuclides can be ingested or injected into the body. They have largely replaced devices based on radionuclide sources due to their advantages.
Iaea quality control atlas for scintillation camera systems. Gamma camera systems are chosen based on departmen tal needs and the specifications which the manufacturers define as the camera performance characteristics. We also briefly analyse and propose a novel design for a single photon emission computed tomography system. Just like an xray, the gamma camera will yield a twodimensional projection of a threedimensional object. The camera accumulates counts of gamma photons, which are detected by crystals in the camera. Gamma cameras or scintillation cameras are pieces of apparatus which allow radiologists to carry out scintigraphy scans, tests which provide detailed diagnoses about the functioning of the thyroid, the heart, the lungs and many other parts of the body. Reject rays scattered in the body no useful spatial information 3. Nuclear medicine scanning involves the use of radioisotopes and so has the usual risks associated with ionising radiation. This information is typically presented as crosssectional slices through the patient, but can be easily reformatted and manipulated as needed. May 03, 2020 the gamma camera is positioned over the patient and as the tracer material travels through the body and emits radiation, the camera picks it up. Quality control of gamma camera with spect system is highly valuable for assurance performance characteristic. Lars johansson, in principles of translational science in medicine.
May 15, 2012 gamma rays cause some ionisation therefore the patient will be exposed to some radioactivity as well as the nursespatients family. Basic principles of gamma camera imaging and quality control. Solid gamma cameras offer many potential benefits over conventional nai crystal imaging. The advantages of these systems are increased resolution because of the reduced imaging distance nearly 8 mm fwhm and dramatically increased sensitivity because there are multiple detectors four times the sensitivity of a gamma camera acquiring the same slice 14 15 fig. Advantages and disadvantages of gamma rays when compared with xrays for radiographic inspection are listed. Also because of all the gamma escaping from the reactor and its coolant much money needs to be spent shielding people from the gammas. Some disadvantages are present however, such as the possibility of a patient that is worried about being exposed to the radiation. Dualhead spect installations comprise 64% of the gamma camera installed base down from 70% in 2008 spectct camera installed base increased from 2% of the installed base in 2008 to 9% in 2011 69% of the spectct and spect camera installed base are considered to be general purpose 31% are dedicated cardiac cameras. Manufacturing and remanufacturing an economical and ecological approach to gamma camera. Describe how to perform basic qc tests and assess acceptable performance. High resolution and sensitivity gamma camera with active septa. Thereafter, we test again the gammacamera obtained values changing, once a time.
The content has been established from the contributions of many persons and represents a wide range of situations from around the world and from scintillation camera systems produced by different manufacturers. List basic gamma camera calibrations and how they affect performance. No longer do you have to waste your time and energy in developing the roll of film in a dark room. The teaching medical physics resources are designed for teaching 1416 science using examples from medical physics. List performance characteristics of gamma cameras and features affecting performance. Your nuclear medicine gamma camera scan continued are there any risks. Charley gallaygetty images entertainmentgetty images. Improvements in gamma camera technology are aimed at improving the spatial resolution, sensitivity, and uniformity of response as seen in the image.
With digital cameras, you simply click the picture and transfer it to your computer using the cameras data cable. This is probably the most significant of all digital camera advantages. Highintensity gamma ray bursts can come from bombs, supernovas and equipment used to treat cancer. The procedure is very similar to the typical nuclear medicine planar imaging using a gamma camera. Xrays are not absorbed very much by air, hence specimen need not be in an evacuated chamber. Collimators for a camera to work, we need to be able to reconstruct where the gamma ray came from. This quality control atlas for scintillation camera systems has been developed under the auspices of the iaea.