Procedure Overview
What is a barium swallow
A barium swallow is a radiographic (x-ray) examination of the upper gastrointestinal (GI) tract, specifically the pharynx (back of mouth and throat) and the esophagus (hollow tube of muscle extending from below the tongue to the stomach). The pharynx and esophagus are made visible on x-ray film by a liquid suspension called barium. A barium swallow may be performed separately or as part of an upper gastrointestinal (UGI) series, which evaluates the esophagus, stomach, and duodenum (first part of the small intestine).
X-rays use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film. X-rays are made by using external radiation to produce images of the body, its organs, and other internal structures for diagnostic purposes. X-rays pass through body tissues onto specially-treated plates (similar to camera film) and a “negative” type picture is made (the more solid a structure is, the whiter it appears on the film).
Fluoroscopy is often used during a barium swallow. Fluoroscopy is a study of moving body structures - similar to an x-ray “movie.” A continuous x-ray beam is passed through the body part being examined, and is transmitted to a TV-like monitor so that the body part and its motion can be seen in detail. In barium x-rays, fluoroscopy allows the radiologist to see the movement of the barium through the pharynx and esophagus as a person drinks it, hence the name barium swallow.
Indications for the Procedure
A barium swallow may be performed to diagnose structural or functional abnormalities of the pharynx and esophagus. These abnormalities may include, but are not limited to, the following:
• cancers of the head, neck, pharynx, and esophagus
• tumors
• hiatal hernia - upward movement of the stomach, either into or alongside the esophagus
• structural problems, such as diverticula, strictures, or polyps (growths)
• esophageal varices (enlarged veins)
• muscle disorders (pharyngeal or esophageal), such as dysphagia (difficulty swallowing) or spasms (pharyngeal or esophageal)
• achalasia - the lower esophageal sphincter muscle does not relax and allow food to pass into the stomach
• gastroesophageal reflux disease (GERD) and ulcers
Friday, December 18, 2009
Barium Enema Preparation
To conduct the most accurate barium enema test, the patient must follow a prescribed diet and bowel preparation instructions prior to the test. This preparation commonly includes restricted intake of diary products and a liquid diet for 24 hours prior to the test, in addition to drinking large amounts of water or clear liquids 12–24 hours before the test. Patients may also be given laxatives, and asked to give themselves a cleansing enema.
In addition to the prescribed diet and bowel preparation prior to the test, the patient can expect the following during a barium enema:
They will be well draped with a gown as they are placed on a tilting x-ray table.
As the barium or air is injected into the intestine, they may experience cramping pains or the urge to defecate.
The patient will be instructed to take slow, deep breaths through the mouth to ease any discomfort.
In addition to the prescribed diet and bowel preparation prior to the test, the patient can expect the following during a barium enema:
They will be well draped with a gown as they are placed on a tilting x-ray table.
As the barium or air is injected into the intestine, they may experience cramping pains or the urge to defecate.
The patient will be instructed to take slow, deep breaths through the mouth to ease any discomfort.
Gastrointestinal Barium Enema Preparation
Day Before Exam
8:00 a.m. Eat light meal.
9:00 a.m. Drink 8 oz. clear liquid.
10:00 a.m. Drink 8 oz. clear liquid.
11:00 a.m. Drink 8 oz. clear liquid.
12:30 p.m. Take magnesium citrate effervescent laxative. To 6 oz. of cold water, slowly add contents of packet while gently stirring. After effervescence stops, stir again and drink. Or, drink 10 fluid oz. of magnesium citrate oral solution.
Eat a light liquid meal (bouillon, fruit juice, and plain gelatin). No solid foods. No dairy products (milk, cream, or cheese).
2:00 p.m. Drink 8 oz. clear liquid.
3:00 p.m. Drink 8 oz. clear liquid.
4:00 p.m. Drink 8 oz. clear liquid.
6:00 p.m. Eat a light liquid meal (bouillon, fruit juice, and plain gelatin). No solid foods. No dairy products (milk, cream, or cheese).
After eating, take four yellow bisacodyl tablets. Swallow tablets whole with a full glass of water. Do not chew or dissolve tablets.
Day of Exam
Eat no breakfast.
If you are being treated for a renal failure, consult your renal physician for special preparation.
8:00 a.m. Eat light meal.
9:00 a.m. Drink 8 oz. clear liquid.
10:00 a.m. Drink 8 oz. clear liquid.
11:00 a.m. Drink 8 oz. clear liquid.
12:30 p.m. Take magnesium citrate effervescent laxative. To 6 oz. of cold water, slowly add contents of packet while gently stirring. After effervescence stops, stir again and drink. Or, drink 10 fluid oz. of magnesium citrate oral solution.
Eat a light liquid meal (bouillon, fruit juice, and plain gelatin). No solid foods. No dairy products (milk, cream, or cheese).
2:00 p.m. Drink 8 oz. clear liquid.
3:00 p.m. Drink 8 oz. clear liquid.
4:00 p.m. Drink 8 oz. clear liquid.
6:00 p.m. Eat a light liquid meal (bouillon, fruit juice, and plain gelatin). No solid foods. No dairy products (milk, cream, or cheese).
After eating, take four yellow bisacodyl tablets. Swallow tablets whole with a full glass of water. Do not chew or dissolve tablets.
Day of Exam
Eat no breakfast.
If you are being treated for a renal failure, consult your renal physician for special preparation.
Monday, December 14, 2009
Implementing PACS in a Hospital Setting
Over the past two decades, groups of computer scientists, electronic design engineers, and physicians from universities and industry have achieved an electronic environment for the practice of radiography, with PACS comprising the radiography component of this revolution. It has become evident recently that the efficiencies and cost savings of PACS are more fully realized when they are part of an enterprise-wide electronic medical record. The installation of PACS requires careful planning by all the various stakeholders over many months prior to installation. All of the users must be aware of the initial disruption that will occur as they become familiar with system processes and procedures.
Modern fourth-generation PACS is linked to radiology and hospital information systems. PACS consists of electronic acquisition sites-a robust network intelligently managed by a server as well as multiple viewing sites and an archive. The details of how these components are linked and their workflow analysis determines the success of PACS. As PACS evolves over time, components are frequently replaced, and the users must continually learn about new and improved functionalities. The digital medical revolution is rapidly being adopted in many medical centers, improving patient care.
The PACS workflow itself must be described before we elaborate on its role in network systems. Image acquisition by cassettes using films is replaced by specially designed filmless cassettes, which can be used several times. The basic components of any PACS system include an image acquisition device (such as film cassettes, video frame grabbers, and digital imaging modalities like CT or MRI), an image display station, and database management and image storage devices. Patient images are acquired from the radiography or digital imaging modalities and sent to the PACS workstation. The images are viewed and interpreted there, and the interpretation results are made available to the physicians within the hospital network. An image storage backup system stores images on optical disks and MODs. Images are stored for a time period specified in each hospital's state and local rules.
The images from a hospital without a radiologist can be sent to other hospitals. Modalities including CT, MRI, ultrasound, computed radiography, and nuclear medicine send images to PACS servers in other hospitals directly or via a network gateway. Images can be transmitted on a regional hospital local area network (LAN), then onto high-speed phone circuits to reach the hospital with PACS. They then go onto the network core and PACS servers.
References
1. E.L. Siegel and B.I. Reiner, "Filmless Radiology at the Baltimore VA Medical Center: A 9 Year Retrospective," Comput Med Imaging Graph, 27 (2–3) 101–109 (2003).
2. P. Mildenberger, M. Eichelberg, E. Martin. Introduction to the DICOM standard," Eur Radiol., 12 (4) 920–927 (2002). Epub 2001 Sept. 15.
3. B.L.T. Guthrie, C. Price, J. Zaleski, E. Backensto, "Digital Imaging and Communications in Medicine (DICOM) Archive is a Dynamic Component of a Clinician Image-related Workflow Solution," J Digit Imaging, 14 (2 Suppl 1)190–193 (2001).
4. J. Eng, J.P. Leal, W. Shu, G. Yang Liang, "Collaboration System for Radiology Workstations," Radiographics, 22 (5) e5 (2002).
Modern fourth-generation PACS is linked to radiology and hospital information systems. PACS consists of electronic acquisition sites-a robust network intelligently managed by a server as well as multiple viewing sites and an archive. The details of how these components are linked and their workflow analysis determines the success of PACS. As PACS evolves over time, components are frequently replaced, and the users must continually learn about new and improved functionalities. The digital medical revolution is rapidly being adopted in many medical centers, improving patient care.
The PACS workflow itself must be described before we elaborate on its role in network systems. Image acquisition by cassettes using films is replaced by specially designed filmless cassettes, which can be used several times. The basic components of any PACS system include an image acquisition device (such as film cassettes, video frame grabbers, and digital imaging modalities like CT or MRI), an image display station, and database management and image storage devices. Patient images are acquired from the radiography or digital imaging modalities and sent to the PACS workstation. The images are viewed and interpreted there, and the interpretation results are made available to the physicians within the hospital network. An image storage backup system stores images on optical disks and MODs. Images are stored for a time period specified in each hospital's state and local rules.
The images from a hospital without a radiologist can be sent to other hospitals. Modalities including CT, MRI, ultrasound, computed radiography, and nuclear medicine send images to PACS servers in other hospitals directly or via a network gateway. Images can be transmitted on a regional hospital local area network (LAN), then onto high-speed phone circuits to reach the hospital with PACS. They then go onto the network core and PACS servers.
References
1. E.L. Siegel and B.I. Reiner, "Filmless Radiology at the Baltimore VA Medical Center: A 9 Year Retrospective," Comput Med Imaging Graph, 27 (2–3) 101–109 (2003).
2. P. Mildenberger, M. Eichelberg, E. Martin. Introduction to the DICOM standard," Eur Radiol., 12 (4) 920–927 (2002). Epub 2001 Sept. 15.
3. B.L.T. Guthrie, C. Price, J. Zaleski, E. Backensto, "Digital Imaging and Communications in Medicine (DICOM) Archive is a Dynamic Component of a Clinician Image-related Workflow Solution," J Digit Imaging, 14 (2 Suppl 1)190–193 (2001).
4. J. Eng, J.P. Leal, W. Shu, G. Yang Liang, "Collaboration System for Radiology Workstations," Radiographics, 22 (5) e5 (2002).
PACS Viewer (Display System)
A PACS viewer – which is essentially a basic PC with specialized software and a high-resolution monitor – allows any health care professional to view medical images made in a wide range of imaging modalities. No longer is it necessary to deal with complicated film developing equipment and expensive and toxic chemicals. Images made with MRI, EKG, EEG, CT, CAT scans or X-rays can be saved as digital images and studied with a pacs viewer.
Medical Imaging Enters the Digital Age Picture Archive and Communications, or pacs systems, were first used at the Ohio State University Medical Center in 1991. At that time, PACS systems were quite expensive; only major hospitals could afford the mid-to-high six figure price tag of such systems. Nonetheless, over the ensuing decade, OSUMC PACS systems saved over $1 million dollars, thus paying for itself. In addition, it saved thousands of man-hours on the part of physicians, reducing the time between initial consultation and final dictation of a case to three hours. PACS Workstations Any personal computers that are tied into the hospital or clinic LAN can function as pacs workstations , provided that the correct software is installed and you have high-resolution monitors. Using a current PC as a PACS viewer saves money and makes better use of existing resources.
PACS systems make it possible for any authorized person to view medical images on these PACS viewers; they can even be shared with colleagues anywhere in the world over the World Wide Web for purposes of consultation. Multi-Functional PACS systems do more than allow users to look at images; they are a complete integrated system for archival storage of all patient records as well patient scheduling, and most important of all, billing. At PACS workstations, clinic administrative personnel can accomplish many different tasks in one convenient place.
The PAC viewer is also suitable for all specialties and every area of medicine; PAC workstations for radiology, cardiology, mammography and even veterinary medicine. In short, the PACS viewer is for any hospital or clinic facility that wishes to deliver the best health care services at the lowest possible cost.
Medical Imaging Enters the Digital Age Picture Archive and Communications, or pacs systems, were first used at the Ohio State University Medical Center in 1991. At that time, PACS systems were quite expensive; only major hospitals could afford the mid-to-high six figure price tag of such systems. Nonetheless, over the ensuing decade, OSUMC PACS systems saved over $1 million dollars, thus paying for itself. In addition, it saved thousands of man-hours on the part of physicians, reducing the time between initial consultation and final dictation of a case to three hours. PACS Workstations Any personal computers that are tied into the hospital or clinic LAN can function as pacs workstations , provided that the correct software is installed and you have high-resolution monitors. Using a current PC as a PACS viewer saves money and makes better use of existing resources.
PACS systems make it possible for any authorized person to view medical images on these PACS viewers; they can even be shared with colleagues anywhere in the world over the World Wide Web for purposes of consultation. Multi-Functional PACS systems do more than allow users to look at images; they are a complete integrated system for archival storage of all patient records as well patient scheduling, and most important of all, billing. At PACS workstations, clinic administrative personnel can accomplish many different tasks in one convenient place.
The PAC viewer is also suitable for all specialties and every area of medicine; PAC workstations for radiology, cardiology, mammography and even veterinary medicine. In short, the PACS viewer is for any hospital or clinic facility that wishes to deliver the best health care services at the lowest possible cost.
Quantum Mottle And Radiographic Image Quality
Any critique of radio graphic image quality must include an evaluation of quantum mottle, a fundamental limitation of the imaging process. Using an illustrative analogy, this article explains the concept of quantum mottle and defines the quantum sink in an imaging chain. The article also describes the interdependence between quantum mottle and other system parameters, including spatial resolution, contrast resolution and total system speed.
Radiographic image quality characterizes the ability of an imaging system to accurately depict structures in a radiographed object. Six components affect image quality -- spatial resolution (or sharpness), contrast, density, radiographic mottle (or noise), distortion and artifacts. Of these six parameters, radiographic mottle is the most difficult to understand and relate to the imaging process. Radiographic mottle creates a grainy, blotchy, textured or snowy appearance in a radiographic image.
If an image were obtained of a phantom of uniform composition and thickness, the resulting film would have an irregular appearance. Optical density is not consistent throughout the image of the phantom, but rather small differences are present among nearby regions. One reason for this variation is the manifestation of radiographic mottle. Consequently, the imaging process does not render a completely faithful reproduction of the object. High levels of noise produce more variation in film optical density and inhibit the depiction of low-contrast structures.
Film graininess, nonuniformity of screen phosphor and quantum mottle contribute to overall radiographic mottle. Of these three factors, quantum mottle is the dominant component and is the most important consideration regarding noise in the image. Quantum mottle is defined as the statistical fluctuation in the number of photons per unit area that contribute to image formation.
Subject contrast -- in the form of varying x-ray intensity exiting the patient -- must be detected and then converted to an observable form by the imaging system. X-ray photons absorbed in the intensifying screen become the initial information carriers for image formation. However, the detected photos exhibit statistical variations because x-ray emission from the target and interactions with matter, including the patient and the screen, are random events. Quantum mottle becomes more pronounced when the number of x-ray photos absorbed in the screen is decreased, such as by reducing the radiation dose.
The following analogy illustrates the concept of quantum mottle. Imagine that two flat, metal objects are placed on the sand at the beach. They could be of any shape or size, but suppose they are a simple circle and triangle. These two items are confined to a specific region with delineated boundaries -- a sandbox. A passing radiography student is blindfolded and then asked to place his or her finger at various points within the sandbox. The finger acts as a detector, sensing the nature of the items it touches. In this example, the metal objects feel hard to the student's touch and the sand feels soft. Metal or sand could be present at any location within the sandbox, and the exact locations and shapes of the metal objects are unknown to the student until he or she can sample all regions throughout the sandbox.
Suppose a second radiography student is asked to record, on a sheet of paper, the location and attributes (hard or soft) of every point that the first student touches in the sandbox. After the first student has sampled a few points, the blindfold is removed and he or she is asked to describe the shapes of the objects by studying the recorded data alone.
The student fails to recognize the shapes of the metal objects because the number of points he or she has sampled is insufficient to visualize their pattern. The total area probed by the student is very small compared with the total area of the sandbox.
As more points are sampled, the metal design begins to become discernible; additional sampling clarifies the structure even further.
Radiographic imaging is similar in many ways to the discrete sampling process employed by the two radiography students exploring the sandbox. In radiography, x-rays detected at the screen denote relative transmission through objects along the photons' paths. X-rays readily pass through radiolucent objects and are absorbed in the screen (represented in the analogy by the sand). Alternatively, x-rays completely removed by the object are not incident on the screen (represented in the analogy by the metal). The final image on film is a composite of these sampling events. Increased photon absorption by the screen (a higher number of information carriers in the imaging chain) reduces quantum mottle and improves visualization of the structure.
Radiographic image quality characterizes the ability of an imaging system to accurately depict structures in a radiographed object. Six components affect image quality -- spatial resolution (or sharpness), contrast, density, radiographic mottle (or noise), distortion and artifacts. Of these six parameters, radiographic mottle is the most difficult to understand and relate to the imaging process. Radiographic mottle creates a grainy, blotchy, textured or snowy appearance in a radiographic image.
If an image were obtained of a phantom of uniform composition and thickness, the resulting film would have an irregular appearance. Optical density is not consistent throughout the image of the phantom, but rather small differences are present among nearby regions. One reason for this variation is the manifestation of radiographic mottle. Consequently, the imaging process does not render a completely faithful reproduction of the object. High levels of noise produce more variation in film optical density and inhibit the depiction of low-contrast structures.
Film graininess, nonuniformity of screen phosphor and quantum mottle contribute to overall radiographic mottle. Of these three factors, quantum mottle is the dominant component and is the most important consideration regarding noise in the image. Quantum mottle is defined as the statistical fluctuation in the number of photons per unit area that contribute to image formation.
Subject contrast -- in the form of varying x-ray intensity exiting the patient -- must be detected and then converted to an observable form by the imaging system. X-ray photons absorbed in the intensifying screen become the initial information carriers for image formation. However, the detected photos exhibit statistical variations because x-ray emission from the target and interactions with matter, including the patient and the screen, are random events. Quantum mottle becomes more pronounced when the number of x-ray photos absorbed in the screen is decreased, such as by reducing the radiation dose.
The following analogy illustrates the concept of quantum mottle. Imagine that two flat, metal objects are placed on the sand at the beach. They could be of any shape or size, but suppose they are a simple circle and triangle. These two items are confined to a specific region with delineated boundaries -- a sandbox. A passing radiography student is blindfolded and then asked to place his or her finger at various points within the sandbox. The finger acts as a detector, sensing the nature of the items it touches. In this example, the metal objects feel hard to the student's touch and the sand feels soft. Metal or sand could be present at any location within the sandbox, and the exact locations and shapes of the metal objects are unknown to the student until he or she can sample all regions throughout the sandbox.
Suppose a second radiography student is asked to record, on a sheet of paper, the location and attributes (hard or soft) of every point that the first student touches in the sandbox. After the first student has sampled a few points, the blindfold is removed and he or she is asked to describe the shapes of the objects by studying the recorded data alone.
The student fails to recognize the shapes of the metal objects because the number of points he or she has sampled is insufficient to visualize their pattern. The total area probed by the student is very small compared with the total area of the sandbox.
As more points are sampled, the metal design begins to become discernible; additional sampling clarifies the structure even further.
Radiographic imaging is similar in many ways to the discrete sampling process employed by the two radiography students exploring the sandbox. In radiography, x-rays detected at the screen denote relative transmission through objects along the photons' paths. X-rays readily pass through radiolucent objects and are absorbed in the screen (represented in the analogy by the sand). Alternatively, x-rays completely removed by the object are not incident on the screen (represented in the analogy by the metal). The final image on film is a composite of these sampling events. Increased photon absorption by the screen (a higher number of information carriers in the imaging chain) reduces quantum mottle and improves visualization of the structure.
BENEFITS OF PACS
I cannot begin to describe all the values of a PACS on this page but I hope to stimulate some ideas. Radiograph's primary mission is to create and store information for the review of others involved in patient care. The information just happens to be a piece of film and it's interpretive results. Within this mission Radiography must make this information accessible upon demand. As all of us know the demand sometimes exceeds the system capacity and that is where a PACS has its advantages.
A PACS has tremendous benefits and values outside of radiology as well as internally. The biggest benefit derived from a PACS is breaking the physical as well as time barrier for information exchange. The other benefit from PACS implementation is not the decreased operating cost in Radiology. The radiology cost benefit, while significant, does not compare with the system wide benefits of networking images throughout the hospital and physician offices.
To explain this point look at what happens within the radiology department film library. Basically the film librarians job is to maintain the patient files in proper order through preset procedures while securing the files from unauthorized access. In essence this means the film librarian must pull, file, re-file and log every action in order to account for the patient file location and other medical information contained in the folder whether by computer or manually. Although some of this record keeping is now performed by a RIS the image handling is still performed manually.
Once an exam is completed it is accessed by clinicians and other ancillary staff approximately 8 times more than that for radiology. Clinicians are continually accessing the film jacket not only to review the films but to review the report because the report is not on the patient chart along with the x-ray when they perform rounds. Everyone knows this function is not limited to a single physician, it usually consist of two or more physicians working on the same patient. This is then multiplied again if it is a teaching institution.
Put all of this into an electronic world and the film librarians job shrinks to providing copies and reprints for clinicians etc. who are outside the hospital network. Some radiologists are going to be happier since comparative exams are always available. The clinicians are more productive if all the information they need is available at one place.
The benefits do not stop here. It does not stretch ones imagination to reveal the global effects of instituting a PACS. The possibilities range from an Intranet for physician image viewing and consultation to utilizing the Internet for patient education and exam scheduling.
Quantum Mottle And Radiographic Image Quality
Any critique of radio graphic image quality must include an evaluation of quantum mottle, a fundamental limitation of the imaging process. Using an illustrative analogy, this article explains the concept of quantum mottle and defines the quantum sink in an imaging chain. The article also describes the interdependence between quantum mottle and other system parameters, including spatial resolution, contrast resolution and total system speed.
Radiographic image quality characterizes the ability of an imaging system to accurately depict structures in a radiographed object. Six components affect image quality -- spatial resolution (or sharpness), contrast, density, radiographic mottle (or noise), distortion and artifacts. Of these six parameters, radiographic mottle is the most difficult to understand and relate to the imaging process. Radiographic mottle creates a grainy, blotchy, textured or snowy appearance in a radiographic image.
If an image were obtained of a phantom of uniform composition and thickness, the resulting film would have an irregular appearance. Optical density is not consistent throughout the image of the phantom, but rather small differences are present among nearby regions. One reason for this variation is the manifestation of radiographic mottle. Consequently, the imaging process does not render a completely faithful reproduction of the object. High levels of noise produce more variation in film optical density and inhibit the depiction of low-contrast structures.
Film graininess, nonuniformity of screen phosphor and quantum mottle contribute to overall radiographic mottle. Of these three factors, quantum mottle is the dominant component and is the most important consideration regarding noise in the image. Quantum mottle is defined as the statistical fluctuation in the number of photons per unit area that contribute to image formation.
Subject contrast -- in the form of varying x-ray intensity exiting the patient -- must be detected and then converted to an observable form by the imaging system. X-ray photons absorbed in the intensifying screen become the initial information carriers for image formation. However, the detected photos exhibit statistical variations because x-ray emission from the target and interactions with matter, including the patient and the screen, are random events. Quantum mottle becomes more pronounced when the number of x-ray photos absorbed in the screen is decreased, such as by reducing the radiation dose.
The following analogy illustrates the concept of quantum mottle. Imagine that two flat, metal objects are placed on the sand at the beach. They could be of any shape or size, but suppose they are a simple circle and triangle. These two items are confined to a specific region with delineated boundaries -- a sandbox. A passing radiography student is blindfolded and then asked to place his or her finger at various points within the sandbox. The finger acts as a detector, sensing the nature of the items it touches. In this example, the metal objects feel hard to the student's touch and the sand feels soft. Metal or sand could be present at any location within the sandbox, and the exact locations and shapes of the metal objects are unknown to the student until he or she can sample all regions throughout the sandbox.
Suppose a second radiography student is asked to record, on a sheet of paper, the location and attributes (hard or soft) of every point that the first student touches in the sandbox. After the first student has sampled a few points, the blindfold is removed and he or she is asked to describe the shapes of the objects by studying the recorded data alone.
The student fails to recognize the shapes of the metal objects because the number of points he or she has sampled is insufficient to visualize their pattern. The total area probed by the student is very small compared with the total area of the sandbox.
As more points are sampled, the metal design begins to become discernible; additional sampling clarifies the structure even further. Radiographic imaging is similar in many ways to the discrete sampling process employed by the two radiography students exploring the sandbox. In radiography, x-rays detected at the screen denote relative transmission through objects along the photons' paths. X-rays readily pass through radiolucent objects and are absorbed in the screen (represented in the analogy by the sand). Alternatively, x-rays completely removed by the object are not incident on the screen (represented in the analogy by the metal). The final image on film is a composite of these sampling events. Increased photon absorption by the screen (a higher number of information carriers in the imaging chain) reduces quantum mottle and improves visualization of the structure
A PACS has tremendous benefits and values outside of radiology as well as internally. The biggest benefit derived from a PACS is breaking the physical as well as time barrier for information exchange. The other benefit from PACS implementation is not the decreased operating cost in Radiology. The radiology cost benefit, while significant, does not compare with the system wide benefits of networking images throughout the hospital and physician offices.
To explain this point look at what happens within the radiology department film library. Basically the film librarians job is to maintain the patient files in proper order through preset procedures while securing the files from unauthorized access. In essence this means the film librarian must pull, file, re-file and log every action in order to account for the patient file location and other medical information contained in the folder whether by computer or manually. Although some of this record keeping is now performed by a RIS the image handling is still performed manually.
Once an exam is completed it is accessed by clinicians and other ancillary staff approximately 8 times more than that for radiology. Clinicians are continually accessing the film jacket not only to review the films but to review the report because the report is not on the patient chart along with the x-ray when they perform rounds. Everyone knows this function is not limited to a single physician, it usually consist of two or more physicians working on the same patient. This is then multiplied again if it is a teaching institution.
Put all of this into an electronic world and the film librarians job shrinks to providing copies and reprints for clinicians etc. who are outside the hospital network. Some radiologists are going to be happier since comparative exams are always available. The clinicians are more productive if all the information they need is available at one place.
The benefits do not stop here. It does not stretch ones imagination to reveal the global effects of instituting a PACS. The possibilities range from an Intranet for physician image viewing and consultation to utilizing the Internet for patient education and exam scheduling.
Quantum Mottle And Radiographic Image Quality
Any critique of radio graphic image quality must include an evaluation of quantum mottle, a fundamental limitation of the imaging process. Using an illustrative analogy, this article explains the concept of quantum mottle and defines the quantum sink in an imaging chain. The article also describes the interdependence between quantum mottle and other system parameters, including spatial resolution, contrast resolution and total system speed.
Radiographic image quality characterizes the ability of an imaging system to accurately depict structures in a radiographed object. Six components affect image quality -- spatial resolution (or sharpness), contrast, density, radiographic mottle (or noise), distortion and artifacts. Of these six parameters, radiographic mottle is the most difficult to understand and relate to the imaging process. Radiographic mottle creates a grainy, blotchy, textured or snowy appearance in a radiographic image.
If an image were obtained of a phantom of uniform composition and thickness, the resulting film would have an irregular appearance. Optical density is not consistent throughout the image of the phantom, but rather small differences are present among nearby regions. One reason for this variation is the manifestation of radiographic mottle. Consequently, the imaging process does not render a completely faithful reproduction of the object. High levels of noise produce more variation in film optical density and inhibit the depiction of low-contrast structures.
Film graininess, nonuniformity of screen phosphor and quantum mottle contribute to overall radiographic mottle. Of these three factors, quantum mottle is the dominant component and is the most important consideration regarding noise in the image. Quantum mottle is defined as the statistical fluctuation in the number of photons per unit area that contribute to image formation.
Subject contrast -- in the form of varying x-ray intensity exiting the patient -- must be detected and then converted to an observable form by the imaging system. X-ray photons absorbed in the intensifying screen become the initial information carriers for image formation. However, the detected photos exhibit statistical variations because x-ray emission from the target and interactions with matter, including the patient and the screen, are random events. Quantum mottle becomes more pronounced when the number of x-ray photos absorbed in the screen is decreased, such as by reducing the radiation dose.
The following analogy illustrates the concept of quantum mottle. Imagine that two flat, metal objects are placed on the sand at the beach. They could be of any shape or size, but suppose they are a simple circle and triangle. These two items are confined to a specific region with delineated boundaries -- a sandbox. A passing radiography student is blindfolded and then asked to place his or her finger at various points within the sandbox. The finger acts as a detector, sensing the nature of the items it touches. In this example, the metal objects feel hard to the student's touch and the sand feels soft. Metal or sand could be present at any location within the sandbox, and the exact locations and shapes of the metal objects are unknown to the student until he or she can sample all regions throughout the sandbox.
Suppose a second radiography student is asked to record, on a sheet of paper, the location and attributes (hard or soft) of every point that the first student touches in the sandbox. After the first student has sampled a few points, the blindfold is removed and he or she is asked to describe the shapes of the objects by studying the recorded data alone.
The student fails to recognize the shapes of the metal objects because the number of points he or she has sampled is insufficient to visualize their pattern. The total area probed by the student is very small compared with the total area of the sandbox.
As more points are sampled, the metal design begins to become discernible; additional sampling clarifies the structure even further. Radiographic imaging is similar in many ways to the discrete sampling process employed by the two radiography students exploring the sandbox. In radiography, x-rays detected at the screen denote relative transmission through objects along the photons' paths. X-rays readily pass through radiolucent objects and are absorbed in the screen (represented in the analogy by the sand). Alternatively, x-rays completely removed by the object are not incident on the screen (represented in the analogy by the metal). The final image on film is a composite of these sampling events. Increased photon absorption by the screen (a higher number of information carriers in the imaging chain) reduces quantum mottle and improves visualization of the structure
BENEFITS OF PACS
I cannot begin to describe all the values of a PACS on this page but I hope to stimulate some ideas. Radiograph's primary mission is to create and store information for the review of others involved in patient care. The information just happens to be a piece of film and it's interpretive results. Within this mission Radiography must make this information accessible upon demand. As all of us know the demand sometimes exceeds the system capacity and that is where a PACS has its advantages.
A PACS has tremendous benefits and values outside of radiology as well as internally. The biggest benefit derived from a PACS is breaking the physical as well as time barrier for information exchange. The other benefit from PACS implementation is not the decreased operating cost in Radiology. The radiology cost benefit, while significant, does not compare with the system wide benefits of networking images throughout the hospital and physician offices.
To explain this point look at what happens within the radiology department film library. Basically the film librarians job is to maintain the patient files in proper order through preset procedures while securing the files from unauthorized access. In essence this means the film librarian must pull, file, re-file and log every action in order to account for the patient file location and other medical information contained in the folder whether by computer or manually. Although some of this record keeping is now performed by a RIS the image handling is still performed manually.
Once an exam is completed it is accessed by clinicians and other ancillary staff approximately 8 times more than that for radiology. Clinicians are continually accessing the film jacket not only to review the films but to review the report because the report is not on the patient chart along with the x-ray when they perform rounds. Everyone knows this function is not limited to a single physician, it usually consist of two or more physicians working on the same patient. This is then multiplied again if it is a teaching institution.
Put all of this into an electronic world and the film librarians job shrinks to providing copies and reprints for clinicians etc. who are outside the hospital network. Some radiologists are going to be happier since comparative exams are always available. The clinicians are more productive if all the information they need is available at one place.
The benefits do not stop here. It does not stretch ones imagination to reveal the global effects of instituting a PACS. The possibilities range from an Intranet for physician image viewing and consultation to utilizing the Internet for patient education and exam scheduling.
Quantum Mottle And Radiographic Image Quality
Any critique of radio graphic image quality must include an evaluation of quantum mottle, a fundamental limitation of the imaging process. Using an illustrative analogy, this article explains the concept of quantum mottle and defines the quantum sink in an imaging chain. The article also describes the interdependence between quantum mottle and other system parameters, including spatial resolution, contrast resolution and total system speed.
Radiographic image quality characterizes the ability of an imaging system to accurately depict structures in a radiographed object. Six components affect image quality -- spatial resolution (or sharpness), contrast, density, radiographic mottle (or noise), distortion and artifacts. Of these six parameters, radiographic mottle is the most difficult to understand and relate to the imaging process. Radiographic mottle creates a grainy, blotchy, textured or snowy appearance in a radiographic image.
If an image were obtained of a phantom of uniform composition and thickness, the resulting film would have an irregular appearance. Optical density is not consistent throughout the image of the phantom, but rather small differences are present among nearby regions. One reason for this variation is the manifestation of radiographic mottle. Consequently, the imaging process does not render a completely faithful reproduction of the object. High levels of noise produce more variation in film optical density and inhibit the depiction of low-contrast structures.
Film graininess, nonuniformity of screen phosphor and quantum mottle contribute to overall radiographic mottle. Of these three factors, quantum mottle is the dominant component and is the most important consideration regarding noise in the image. Quantum mottle is defined as the statistical fluctuation in the number of photons per unit area that contribute to image formation.
Subject contrast -- in the form of varying x-ray intensity exiting the patient -- must be detected and then converted to an observable form by the imaging system. X-ray photons absorbed in the intensifying screen become the initial information carriers for image formation. However, the detected photos exhibit statistical variations because x-ray emission from the target and interactions with matter, including the patient and the screen, are random events. Quantum mottle becomes more pronounced when the number of x-ray photos absorbed in the screen is decreased, such as by reducing the radiation dose.
The following analogy illustrates the concept of quantum mottle. Imagine that two flat, metal objects are placed on the sand at the beach. They could be of any shape or size, but suppose they are a simple circle and triangle. These two items are confined to a specific region with delineated boundaries -- a sandbox. A passing radiography student is blindfolded and then asked to place his or her finger at various points within the sandbox. The finger acts as a detector, sensing the nature of the items it touches. In this example, the metal objects feel hard to the student's touch and the sand feels soft. Metal or sand could be present at any location within the sandbox, and the exact locations and shapes of the metal objects are unknown to the student until he or she can sample all regions throughout the sandbox.
Suppose a second radiography student is asked to record, on a sheet of paper, the location and attributes (hard or soft) of every point that the first student touches in the sandbox. After the first student has sampled a few points, the blindfold is removed and he or she is asked to describe the shapes of the objects by studying the recorded data alone.
The student fails to recognize the shapes of the metal objects because the number of points he or she has sampled is insufficient to visualize their pattern. The total area probed by the student is very small compared with the total area of the sandbox.
As more points are sampled, the metal design begins to become discernible; additional sampling clarifies the structure even further. Radiographic imaging is similar in many ways to the discrete sampling process employed by the two radiography students exploring the sandbox. In radiography, x-rays detected at the screen denote relative transmission through objects along the photons' paths. X-rays readily pass through radiolucent objects and are absorbed in the screen (represented in the analogy by the sand). Alternatively, x-rays completely removed by the object are not incident on the screen (represented in the analogy by the metal). The final image on film is a composite of these sampling events. Increased photon absorption by the screen (a higher number of information carriers in the imaging chain) reduces quantum mottle and improves visualization of the structure
A PACS has tremendous benefits and values outside of radiology as well as internally. The biggest benefit derived from a PACS is breaking the physical as well as time barrier for information exchange. The other benefit from PACS implementation is not the decreased operating cost in Radiology. The radiology cost benefit, while significant, does not compare with the system wide benefits of networking images throughout the hospital and physician offices.
To explain this point look at what happens within the radiology department film library. Basically the film librarians job is to maintain the patient files in proper order through preset procedures while securing the files from unauthorized access. In essence this means the film librarian must pull, file, re-file and log every action in order to account for the patient file location and other medical information contained in the folder whether by computer or manually. Although some of this record keeping is now performed by a RIS the image handling is still performed manually.
Once an exam is completed it is accessed by clinicians and other ancillary staff approximately 8 times more than that for radiology. Clinicians are continually accessing the film jacket not only to review the films but to review the report because the report is not on the patient chart along with the x-ray when they perform rounds. Everyone knows this function is not limited to a single physician, it usually consist of two or more physicians working on the same patient. This is then multiplied again if it is a teaching institution.
Put all of this into an electronic world and the film librarians job shrinks to providing copies and reprints for clinicians etc. who are outside the hospital network. Some radiologists are going to be happier since comparative exams are always available. The clinicians are more productive if all the information they need is available at one place.
The benefits do not stop here. It does not stretch ones imagination to reveal the global effects of instituting a PACS. The possibilities range from an Intranet for physician image viewing and consultation to utilizing the Internet for patient education and exam scheduling.
Quantum Mottle And Radiographic Image Quality
Any critique of radio graphic image quality must include an evaluation of quantum mottle, a fundamental limitation of the imaging process. Using an illustrative analogy, this article explains the concept of quantum mottle and defines the quantum sink in an imaging chain. The article also describes the interdependence between quantum mottle and other system parameters, including spatial resolution, contrast resolution and total system speed.
Radiographic image quality characterizes the ability of an imaging system to accurately depict structures in a radiographed object. Six components affect image quality -- spatial resolution (or sharpness), contrast, density, radiographic mottle (or noise), distortion and artifacts. Of these six parameters, radiographic mottle is the most difficult to understand and relate to the imaging process. Radiographic mottle creates a grainy, blotchy, textured or snowy appearance in a radiographic image.
If an image were obtained of a phantom of uniform composition and thickness, the resulting film would have an irregular appearance. Optical density is not consistent throughout the image of the phantom, but rather small differences are present among nearby regions. One reason for this variation is the manifestation of radiographic mottle. Consequently, the imaging process does not render a completely faithful reproduction of the object. High levels of noise produce more variation in film optical density and inhibit the depiction of low-contrast structures.
Film graininess, nonuniformity of screen phosphor and quantum mottle contribute to overall radiographic mottle. Of these three factors, quantum mottle is the dominant component and is the most important consideration regarding noise in the image. Quantum mottle is defined as the statistical fluctuation in the number of photons per unit area that contribute to image formation.
Subject contrast -- in the form of varying x-ray intensity exiting the patient -- must be detected and then converted to an observable form by the imaging system. X-ray photons absorbed in the intensifying screen become the initial information carriers for image formation. However, the detected photos exhibit statistical variations because x-ray emission from the target and interactions with matter, including the patient and the screen, are random events. Quantum mottle becomes more pronounced when the number of x-ray photos absorbed in the screen is decreased, such as by reducing the radiation dose.
The following analogy illustrates the concept of quantum mottle. Imagine that two flat, metal objects are placed on the sand at the beach. They could be of any shape or size, but suppose they are a simple circle and triangle. These two items are confined to a specific region with delineated boundaries -- a sandbox. A passing radiography student is blindfolded and then asked to place his or her finger at various points within the sandbox. The finger acts as a detector, sensing the nature of the items it touches. In this example, the metal objects feel hard to the student's touch and the sand feels soft. Metal or sand could be present at any location within the sandbox, and the exact locations and shapes of the metal objects are unknown to the student until he or she can sample all regions throughout the sandbox.
Suppose a second radiography student is asked to record, on a sheet of paper, the location and attributes (hard or soft) of every point that the first student touches in the sandbox. After the first student has sampled a few points, the blindfold is removed and he or she is asked to describe the shapes of the objects by studying the recorded data alone.
The student fails to recognize the shapes of the metal objects because the number of points he or she has sampled is insufficient to visualize their pattern. The total area probed by the student is very small compared with the total area of the sandbox.
As more points are sampled, the metal design begins to become discernible; additional sampling clarifies the structure even further. Radiographic imaging is similar in many ways to the discrete sampling process employed by the two radiography students exploring the sandbox. In radiography, x-rays detected at the screen denote relative transmission through objects along the photons' paths. X-rays readily pass through radiolucent objects and are absorbed in the screen (represented in the analogy by the sand). Alternatively, x-rays completely removed by the object are not incident on the screen (represented in the analogy by the metal). The final image on film is a composite of these sampling events. Increased photon absorption by the screen (a higher number of information carriers in the imaging chain) reduces quantum mottle and improves visualization of the structure
PACS AND Hospital Information System(HIS), Radiology Information System(RIS)
One of the most important benefits of a PACS system is the workstation! Image viewing on a workstation is available within seconds of being captured by the PACS server. Because the system recognizes patient information data from RIS and HIS hubs it is easy to bring up images using the patient's medical record number, or name and other connecting data such as their date of birth. Before we talk about how the workstation works within the PACS network we should discuss how the PACS server makes viewing images and information possible at the workstation.
Patient information such as the medical record number, name, date-of-birth, type of study, date of study and the like is entered into the PACS record through a data bridge. The data bridge is also a DICOM compatible device that adheres to DICOM subclass standards. Pre-selected information fields from the hospital information system (HIS) and radiology information system (RIS) servers are preset to populate PACS text data fields. This is coordinated with the generation of new images sent to the PACS server from a base device (CR, CT, MRI, etc). DICOM includes compatibility of HIS and RIS information systems networked to a PACS system. The DICOM standards are structured so that the PACS server will distribute images and information as if it were the primary base installed device that originated the data. DICOM also addresses interface standards between network peripheral devices based on "underlying" technologies such as HL7, V2, and 3, which allows information transfer in bulk using document paradigm.
The new DICOM standards version 3.0 of 1993 included the development and expansion of PACS to interface with medical information systems. This was an inclusive enterprise extending from the 1987 formation of Health Level Seven, Inc (HL7). HL7 is a non profit organization that in 1963 acquired ANSI accredited standing as a developing organization. This cooperative group of over 2,000 members representing over 500 corporations encompassing greater than 90% of the vendors of healthcare information system services.
Hospitals input and store patient data using what is known as a hospital information system (HIS). The hospital information system is a network of computers used to enter and store patient’s personal data, such as their full name, date of birth, social security number, insurance billing information, and the like. It contains highly personal and sensitive patient information and legal documents pertaining to the patient. These documents are specifically privacy protected by Federal legislation such as the Health Insurance Portability Act (HIPAA). The Radiology Information System (RIS) is a sub-network of HIS that uses certain data fields from HIS to compile the radiology exam and procedures requisition. HIS and RIS may use the same or different servers to interface with PACS through what is called a HIS/RIS gateway or PACS broker. The gateway uses Health Level Seven protocol since it is the most shared protocol for HIS/RIS records and supports DICOM standards for managing its synchronization into PACS. The functions of the HIS/RIS gateway includes managing, sorting, archiving, distributing, and translating patient text information into PACS and onto images.
The typical scenario is that the radiology department receives a computer generated request for an x-ray study that was place by a unit secretary. In order to enter the study all pre-selected fields would have been filled, such as the ordering physician, type of study, etc. Pertinent clinical data is taken from the clinical information system (CIS) and HIS patient file, and attached to the request to complete it. The accession number (A1015046) or exam number assigned to each study can be used for easy retrieval from PACS.
The radiology request (above) contains pertinent information as it was retrieved from the RIS/HIS gateway. Data fields are set-up according to the specific criteria of the hospital and billing services as well as the way the radiologist inputs. Because the data is populated from the RIS database the requisition and examination selected from the base device worklist matches. Entry errors are abolished since the technologist selects from a workflow list that edits patient information onto the digital images and into PACS for display at the workstation. The union between DICOM and HL7 is even stronger since the new April 2004 upgrades. Transcribed reports are also entered into PACS as HL7 documents so that they are displayed along with image documents.
The picture to the right demonstrates how the RIS/HIS gateway is used to add text patient information to each radiographic image as they are displayed and archived into PACS. Because this information comes from a universal RIS/HIS server that the technologist selected from a work list, patient information errors are minimized. And when patient information is entered incorrectly it can be changed throughout all of the patient's records image and text data files because of the interconnectivity of HIS & RIS to all patient files. This interconnectivity is the precursor to what will in the near future be a totally electronic patient enterprise file made up of Clinical information Systems (CIS), Hospital information system (HIS), and Radiology Information System (RIS), and emerging laboratory and surgical information systems.
Detailed patient information is not transferred to PACS, only those specific data fields needed to add information to radiographic images, reports, or identify files accessed by the RIS/HIS broker. PACS limited query of RIS/HIS information is in compliance with HIPAA standards for accessing patient information on a need-to-share basis. Detailed patient information enterprise files are currently being developed by researchers as a tool to easily access PACS documents, Hospital Information (HIS), and Clinical Information (CIS) files, and the like as a unit file, to enhance patient care strategies.
The picture to the right demonstrates how images can be displayed on the PACS workstation with the same image and study information as contained on the film. This is because of the cooperative nature of DICOM and HL7 data sharing. The simple workstation seen in the picture is used by technologist and file room clerks to verify images on PACS and to retro print images and reports
References
Smith, R., "The digital effectiveness of CR," Journal of Imaging Technology Management., Available at:http://www.imagingeconomics.com/library/200107-13.asp., 2001. PC Consultant Group, Inc.,
"PACS & RIS, P practical outline," Available at:http://www.pccgroup.com/pacs_in_a_pic.htm 2004. U.Ewert, H. Heidt, "Current Status of
European Radiological Standards for DND, ASNT spring conference ANSD IIW micro symposium," Orlando, Fl. 03/22-03/27, 1999, proceedings p. 171-173
U.Ewert, H. Heidt, "Approach for Standardization of X-ray Film Digitizers and Computed Radiography,"
Spring conference ANSD IIW micro symposium,” Orlando, Fl. 03/22-03/27, 1999, proceedings p. 171-173 Kodak Learning Center., available at:http://www.kodak.com/global/en/health/learningCenter/elearn/pacs/adv_sys_con/course/pa... 2004.
Patient information such as the medical record number, name, date-of-birth, type of study, date of study and the like is entered into the PACS record through a data bridge. The data bridge is also a DICOM compatible device that adheres to DICOM subclass standards. Pre-selected information fields from the hospital information system (HIS) and radiology information system (RIS) servers are preset to populate PACS text data fields. This is coordinated with the generation of new images sent to the PACS server from a base device (CR, CT, MRI, etc). DICOM includes compatibility of HIS and RIS information systems networked to a PACS system. The DICOM standards are structured so that the PACS server will distribute images and information as if it were the primary base installed device that originated the data. DICOM also addresses interface standards between network peripheral devices based on "underlying" technologies such as HL7, V2, and 3, which allows information transfer in bulk using document paradigm.
The new DICOM standards version 3.0 of 1993 included the development and expansion of PACS to interface with medical information systems. This was an inclusive enterprise extending from the 1987 formation of Health Level Seven, Inc (HL7). HL7 is a non profit organization that in 1963 acquired ANSI accredited standing as a developing organization. This cooperative group of over 2,000 members representing over 500 corporations encompassing greater than 90% of the vendors of healthcare information system services.
Hospitals input and store patient data using what is known as a hospital information system (HIS). The hospital information system is a network of computers used to enter and store patient’s personal data, such as their full name, date of birth, social security number, insurance billing information, and the like. It contains highly personal and sensitive patient information and legal documents pertaining to the patient. These documents are specifically privacy protected by Federal legislation such as the Health Insurance Portability Act (HIPAA). The Radiology Information System (RIS) is a sub-network of HIS that uses certain data fields from HIS to compile the radiology exam and procedures requisition. HIS and RIS may use the same or different servers to interface with PACS through what is called a HIS/RIS gateway or PACS broker. The gateway uses Health Level Seven protocol since it is the most shared protocol for HIS/RIS records and supports DICOM standards for managing its synchronization into PACS. The functions of the HIS/RIS gateway includes managing, sorting, archiving, distributing, and translating patient text information into PACS and onto images.
The typical scenario is that the radiology department receives a computer generated request for an x-ray study that was place by a unit secretary. In order to enter the study all pre-selected fields would have been filled, such as the ordering physician, type of study, etc. Pertinent clinical data is taken from the clinical information system (CIS) and HIS patient file, and attached to the request to complete it. The accession number (A1015046) or exam number assigned to each study can be used for easy retrieval from PACS.
The radiology request (above) contains pertinent information as it was retrieved from the RIS/HIS gateway. Data fields are set-up according to the specific criteria of the hospital and billing services as well as the way the radiologist inputs. Because the data is populated from the RIS database the requisition and examination selected from the base device worklist matches. Entry errors are abolished since the technologist selects from a workflow list that edits patient information onto the digital images and into PACS for display at the workstation. The union between DICOM and HL7 is even stronger since the new April 2004 upgrades. Transcribed reports are also entered into PACS as HL7 documents so that they are displayed along with image documents.
The picture to the right demonstrates how the RIS/HIS gateway is used to add text patient information to each radiographic image as they are displayed and archived into PACS. Because this information comes from a universal RIS/HIS server that the technologist selected from a work list, patient information errors are minimized. And when patient information is entered incorrectly it can be changed throughout all of the patient's records image and text data files because of the interconnectivity of HIS & RIS to all patient files. This interconnectivity is the precursor to what will in the near future be a totally electronic patient enterprise file made up of Clinical information Systems (CIS), Hospital information system (HIS), and Radiology Information System (RIS), and emerging laboratory and surgical information systems.
Detailed patient information is not transferred to PACS, only those specific data fields needed to add information to radiographic images, reports, or identify files accessed by the RIS/HIS broker. PACS limited query of RIS/HIS information is in compliance with HIPAA standards for accessing patient information on a need-to-share basis. Detailed patient information enterprise files are currently being developed by researchers as a tool to easily access PACS documents, Hospital Information (HIS), and Clinical Information (CIS) files, and the like as a unit file, to enhance patient care strategies.
The picture to the right demonstrates how images can be displayed on the PACS workstation with the same image and study information as contained on the film. This is because of the cooperative nature of DICOM and HL7 data sharing. The simple workstation seen in the picture is used by technologist and file room clerks to verify images on PACS and to retro print images and reports
References
Smith, R., "The digital effectiveness of CR," Journal of Imaging Technology Management., Available at:http://www.imagingeconomics.com/library/200107-13.asp., 2001. PC Consultant Group, Inc.,
"PACS & RIS, P practical outline," Available at:http://www.pccgroup.com/pacs_in_a_pic.htm 2004. U.Ewert, H. Heidt, "Current Status of
European Radiological Standards for DND, ASNT spring conference ANSD IIW micro symposium," Orlando, Fl. 03/22-03/27, 1999, proceedings p. 171-173
U.Ewert, H. Heidt, "Approach for Standardization of X-ray Film Digitizers and Computed Radiography,"
Spring conference ANSD IIW micro symposium,” Orlando, Fl. 03/22-03/27, 1999, proceedings p. 171-173 Kodak Learning Center., available at:http://www.kodak.com/global/en/health/learningCenter/elearn/pacs/adv_sys_con/course/pa... 2004.
WHAT IS TELERADIOGRAPHY?
Teleradiography is the electronic transmission of radiological images from one location to another for the purposes of interpretation and/or consultation. Users in different locations may simultaneously view images with greater access to secondary consultations and improved continuing education.Rapid advances in communications and computing technology have opened up new opportunities for clinical teleradiology. The quality of teleradiology reporting, when carried out properly, is on par with onsite reporting, and offers the potential for increased accuracy and improved patient outcomes. Local and international industry organisations and professional bodies are creating standards, policies and protocols for every aspect of teleradiology in response to concerns about the use of this technology. The key factor for the long-term success of teleradiology has been identified as a commitment to ensuring duty of care to patients (encompassing high-quality service and patient safety) is the first priority. Evidence indicates that increased use of teleradiology will be a step forward if managed well, but requires a commitment to excellence, patience and perseverance
Digital Imaging and Communications in Medicine and PACS
Digital Imaging and Communications in Medicine (DICOM) is a standard for handling, storing, printing, and transmitting information in medical imaging. It includes a file format definition and a network communications protocol. The communication protocol is an application protocol that uses TCP/IP to communicate between systems. DICOM files can be exchanged between two entities that are capable of receiving image and patient data in DICOM format. The National Electrical Manufacturers Association (NEMA) holds the copyright to this standard. It was developed by the DICOM Standards Committee, whose members are also partly members of NEMA.
DICOM enables the integration of scanners, servers, workstations, printers, and network hardware from multiple manufacturers into a picture archiving and communication system (PACS). The different devices come with DICOM conformance statements which clearly state the DICOM classes they support. DICOM has been widely adopted by hospitals and is making inroads in smaller applications like dentists' and doctors' offices.
DICOM enables the integration of scanners, servers, workstations, printers, and network hardware from multiple manufacturers into a picture archiving and communication system (PACS). The different devices come with DICOM conformance statements which clearly state the DICOM classes they support. DICOM has been widely adopted by hospitals and is making inroads in smaller applications like dentists' and doctors' offices.
USES OF PACS
PACS enables fast, easy access to both current and archived images and reports from PCs throughout the Hospital, including physicians’ offices. Without exchanging paperwork or films, we can interpret your test results faster, and quickly share your diagnosis with the experts who will make a difference to your care.
Simultaneous access to images — so multiple experts can contribute to your diagnosis.
No film to go missing between departments — avoids mistakes and speeds up diagnosis.
On-the-spot comparison with previous tests — for better-informed diagnosis.
Voice recognition software generates instant reports — for immediate, comprehensive analysis.
MEDITECH interface — eliminates manual entry errors.
Dedicated Hospital network— allows fast image transfer without interruption.
Internet access — for authorized review of images from anywhere in the world.
Strictest security protocols — to protect patient confidentiality.
Simultaneous access to images — so multiple experts can contribute to your diagnosis.
No film to go missing between departments — avoids mistakes and speeds up diagnosis.
On-the-spot comparison with previous tests — for better-informed diagnosis.
Voice recognition software generates instant reports — for immediate, comprehensive analysis.
MEDITECH interface — eliminates manual entry errors.
Dedicated Hospital network— allows fast image transfer without interruption.
Internet access — for authorized review of images from anywhere in the world.
Strictest security protocols — to protect patient confidentiality.
An Introduction To PACS
Disease evaluation by imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) is an accurate, reproducible, and easily accessible methodology used in pharmaceutical trials. The value of imaging tools in the evaluation of response to chemotherapeutic agents and other disease modifying agents has been noted in the literature.1,2
Imaging tools such as CT, MRI, and positron emission tomography (PET) scans have complemented serological markers like CEA (carcino-embryogenic antigen) and PSA (prostate-specific antigen) in disease-response evaluation following chemotherapy in patients with colon carcinoma and prostate carcinoma. Imaging tools give detailed information regarding extent and spread of the cancer when compared to the biochemical markers during disease response evaluation.1
Response evaluation by biochemical markers can give false positive and often inaccurate assessment of tumor response. Imaging modalities such as CT and MRI are advantageous because subtle and early changes in lesion progression can be documented more accurately.
Imaging core labs coordinate clinical trials workflow using imaging modalities as the follow-up tool. The images are acquired at various sites all over the world and sent to the imaging core lab, which is analogous to a radiology department. The images received from various sites are either hard-copy films or soft-copy images on magneto-optical disks (MODs) and CDs. The image visualization on computer monitors is analogous to image interpretation using picture archiving and communication systems (PACS) in hospital settings.
References
1. Y. Kitagawa, S. Nishizawa, K. Sano, T. Ogasawara et al., "Prospective Comparison of 18F-FDG PET with Conventional Imaging Modalities (MRI, CT, and 67Ga scintigraphy) in Assessment of Combined Intra-arterial Chemotherapy and Radiotherapy for Head and Neck Carcinoma," J Nucl Med, 44 (2) 198–206 (2003).
2. A.R. Padhani and L. Ollivier, "The RECIST (Response Evaluation Criteria in Solid Tumors) Criteria: Implications for Diagnostic Radiologists," Br J Radiol, 74 (887) 983–986 (2001).
3. S.R. Prasad, S. Saini, J.E. Sumner, P.F. Hahn, D. Sahani, G.W. Boland, "Radiological Measurement of Breast Cancer Metastases to Lung and Liver: Comparison Between WHO (Bidimensional) and RECIST (Unidimensional) Guidelines," J Comput Assist Tomogr, 27 (3) 380–384 (2003).
4. V. Trillet-Lenoir, G. Freyer, P. Kaemmerlen et al., "Assessment of Tumour Response to Chemotherapy for Metastatic Colorectal Cancer: Accuracy of the RECIST Criteria," Br J Radiol, 75 (899) 903–908 (2002).
5. M. Li, D. Wilson, M. Wong, A. Xthona, "The Evolution of Display Technologies in PACS Applications," Comput Med Imaging Graph, 27(2–3)175–184 (2003). G. Gamsu and E. Perez, "Picture Archiving and Communication Systems (PACS)," J Thorac Imaging, 18 (3) 165–168 (2003).
6. A.A. Twair, W.C. Torreggiani, S.M. Mahmud, N. Ramesh, B. Hogan, "Significant Savings in Radiologic Report Turnaround Time After Implementation of a Complete Picture Archiving and Communication System (PACS)," J Digit Imaging, 13 (4) 175–177 (2000).
Imaging tools such as CT, MRI, and positron emission tomography (PET) scans have complemented serological markers like CEA (carcino-embryogenic antigen) and PSA (prostate-specific antigen) in disease-response evaluation following chemotherapy in patients with colon carcinoma and prostate carcinoma. Imaging tools give detailed information regarding extent and spread of the cancer when compared to the biochemical markers during disease response evaluation.1
Response evaluation by biochemical markers can give false positive and often inaccurate assessment of tumor response. Imaging modalities such as CT and MRI are advantageous because subtle and early changes in lesion progression can be documented more accurately.
Imaging core labs coordinate clinical trials workflow using imaging modalities as the follow-up tool. The images are acquired at various sites all over the world and sent to the imaging core lab, which is analogous to a radiology department. The images received from various sites are either hard-copy films or soft-copy images on magneto-optical disks (MODs) and CDs. The image visualization on computer monitors is analogous to image interpretation using picture archiving and communication systems (PACS) in hospital settings.
References
1. Y. Kitagawa, S. Nishizawa, K. Sano, T. Ogasawara et al., "Prospective Comparison of 18F-FDG PET with Conventional Imaging Modalities (MRI, CT, and 67Ga scintigraphy) in Assessment of Combined Intra-arterial Chemotherapy and Radiotherapy for Head and Neck Carcinoma," J Nucl Med, 44 (2) 198–206 (2003).
2. A.R. Padhani and L. Ollivier, "The RECIST (Response Evaluation Criteria in Solid Tumors) Criteria: Implications for Diagnostic Radiologists," Br J Radiol, 74 (887) 983–986 (2001).
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Friday, December 4, 2009
Object Contrast
Apart from subject contrast and image contrast which you know very well, there is a third 'contrast' in medical imaging called object contrast - yes.
Object contrast is simply the differences in the anatominal deatails of the patient's body part to be exposed. For more info, check out http://faxil.leeds.ac.uk/learning/iq/contrast/object.xml
Object contrast is simply the differences in the anatominal deatails of the patient's body part to be exposed. For more info, check out http://faxil.leeds.ac.uk/learning/iq/contrast/object.xml
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