Thomas R. Nelson, Ph.D. Professor of Radiology UC San Diego
... • Mutual information is the amount that the uncertainty in B (or A) is reduced when A (or B) is known. • 2) I(A,B) = H(A) + H(B) - H(A,B) • Maximizing the mutual info is equivalent to minimizing the joint entropy (last term) • Advantage in using mutual info over joint entropy is it includes the indi ...
... • Mutual information is the amount that the uncertainty in B (or A) is reduced when A (or B) is known. • 2) I(A,B) = H(A) + H(B) - H(A,B) • Maximizing the mutual info is equivalent to minimizing the joint entropy (last term) • Advantage in using mutual info over joint entropy is it includes the indi ...
Using spectral results in CT imaging
... a spectral view of the pancreas. The user can assign different spectral results to further interrogate a Region of Interest (A) and compare to the 72 keV MonoE image (B). ...
... a spectral view of the pancreas. The user can assign different spectral results to further interrogate a Region of Interest (A) and compare to the 72 keV MonoE image (B). ...
Imaging modalities for preoperative assessment in dental implant
... Ltd., Helsinki, Finland) which produces buccolingual crosssectional tomograms. It was constructed as a multifunctional unit able to meet most dentomaxillofacial radiology needs. Optimal tomographic images can be achieved by using spiral movements where the blurred shadows are placed at equal distanc ...
... Ltd., Helsinki, Finland) which produces buccolingual crosssectional tomograms. It was constructed as a multifunctional unit able to meet most dentomaxillofacial radiology needs. Optimal tomographic images can be achieved by using spiral movements where the blurred shadows are placed at equal distanc ...
MSc Seferis
... Active-matrix flat-panel imager (AMFPI) systems. These technologies for digital image acquisition appeared in the mid-1990s with the use of large field of view (FOV) X-ray phosphors and optical lens assemblies to focus the X-ray induced light output onto a small-area charge coupled device (CCD) phot ...
... Active-matrix flat-panel imager (AMFPI) systems. These technologies for digital image acquisition appeared in the mid-1990s with the use of large field of view (FOV) X-ray phosphors and optical lens assemblies to focus the X-ray induced light output onto a small-area charge coupled device (CCD) phot ...
Digital Image Acquisition and Processing in Medical X
... phosphor systems(SPS),'* also known as computedradiography (CR) systems,and a selenium-detectorbaseddigital chestradiographysystem[(DCS), "Thoravision"].''o In CR systems,the image receptor is a photostimulable phosphor plate, which absorbsand storesa significant portion of the incoming x-ray energy ...
... phosphor systems(SPS),'* also known as computedradiography (CR) systems,and a selenium-detectorbaseddigital chestradiographysystem[(DCS), "Thoravision"].''o In CR systems,the image receptor is a photostimulable phosphor plate, which absorbsand storesa significant portion of the incoming x-ray energy ...
Blind deblurring of spiral CT images
... about the PSF into the algorithm, but these means were not effective. There are Bayesian approaches that utilize prior information about the image and the PSF, such as the total variation [10] and other priors [11], [12]. These approaches introduce new problems of estimating the hyper-parameters. Fu ...
... about the PSF into the algorithm, but these means were not effective. There are Bayesian approaches that utilize prior information about the image and the PSF, such as the total variation [10] and other priors [11], [12]. These approaches introduce new problems of estimating the hyper-parameters. Fu ...
Perception Metrics in Medical Imaging
... with a reasonable degree of certainty. However, another issue is put forward by factor (2): the physicians’ performance should be considered as well because large differences in performance have been found between different observers. Usually physicians’ performance is not perfect and their errors c ...
... with a reasonable degree of certainty. However, another issue is put forward by factor (2): the physicians’ performance should be considered as well because large differences in performance have been found between different observers. Usually physicians’ performance is not perfect and their errors c ...
Innovation, in reach 3D Panoramic Cephalometric Would you like to
... images, the international standard for medical images. Volumes can therefore be exported to any DICOM compatible other software for implant placement or treatment planning. Similarly, the Kodak 9000 3D system software can import DICOM images from other 3D systems. To further simplify sharing of resu ...
... images, the international standard for medical images. Volumes can therefore be exported to any DICOM compatible other software for implant placement or treatment planning. Similarly, the Kodak 9000 3D system software can import DICOM images from other 3D systems. To further simplify sharing of resu ...
A Review of Image Watermarking Applications in Healthcare
... of the image integrity. Alternatively, it can be designed to differentiate manipulated image blocks [5][11][13]. One advantage of DS, based on the cryptographic hashing functions, is that it is legally recognized in most countries. That is not the case of pure watermarking solutions, for example tel ...
... of the image integrity. Alternatively, it can be designed to differentiate manipulated image blocks [5][11][13]. One advantage of DS, based on the cryptographic hashing functions, is that it is legally recognized in most countries. That is not the case of pure watermarking solutions, for example tel ...
Full Text
... are excellent and well meaning; however, the only dose metrics available for reporting are the CTDI metric and measures derived from it, including the DLP. While these CTDI measures are highly standardized and recognized around the world, they are not measures of patient dose (14)—a fact often misun ...
... are excellent and well meaning; however, the only dose metrics available for reporting are the CTDI metric and measures derived from it, including the DLP. While these CTDI measures are highly standardized and recognized around the world, they are not measures of patient dose (14)—a fact often misun ...
Image Guided Surgical Interventions
... cavity. The main limitation of optical endoscopy, however, is the lack of penetration of the illuminating energy (visible light) into solid or opaque tissue structures. Traditionally radiograph imaging has been used as an adjunct or instead of optical imaging inside the body due to its ready availab ...
... cavity. The main limitation of optical endoscopy, however, is the lack of penetration of the illuminating energy (visible light) into solid or opaque tissue structures. Traditionally radiograph imaging has been used as an adjunct or instead of optical imaging inside the body due to its ready availab ...
Tomotherapy: A "Revolution" in Radiation Therapy
... date demonstrates that imaging using megavoltage photons may be adequate for set-up verification, delivery verification and dose reconstruction purposes [6,7]. To improve image quality and reduce the dose to the patient, when used for imaging purposes, the linear accelerator is slightly detuned lead ...
... date demonstrates that imaging using megavoltage photons may be adequate for set-up verification, delivery verification and dose reconstruction purposes [6,7]. To improve image quality and reduce the dose to the patient, when used for imaging purposes, the linear accelerator is slightly detuned lead ...
Standards for Chest Radiography
... radiography units. In addition, grid alignment tends to be less accurate in this situation. * Technical Advances in Chest Radiography: New approaches to image acquisition and display have been introduced in the last decade to circumvent the limitation of conventional film screen studies. Digital rad ...
... radiography units. In addition, grid alignment tends to be less accurate in this situation. * Technical Advances in Chest Radiography: New approaches to image acquisition and display have been introduced in the last decade to circumvent the limitation of conventional film screen studies. Digital rad ...
Slide 1
... License (CAT no. 8135006 or 8201212 – Page 14) The user would select the Full Spine / Full Leg exams from the ...
... License (CAT no. 8135006 or 8201212 – Page 14) The user would select the Full Spine / Full Leg exams from the ...
Radiographic examination of the temporomandibular joint using
... images. A main disadvantage of the CT examination still remains the high radiation dose involved. CBCT is a new technique producing reconstructed images of high diagnostic quality using lower radiation doses than normal CT. According to the manufacturer, owing to the use of the cone-shaped X-ray bea ...
... images. A main disadvantage of the CT examination still remains the high radiation dose involved. CBCT is a new technique producing reconstructed images of high diagnostic quality using lower radiation doses than normal CT. According to the manufacturer, owing to the use of the cone-shaped X-ray bea ...
3D Imaging Systems - Carestream Dental
... lateral extent of the canal morphology prior to treatment. Bottom Middle: 2D image taken after root canal treatment demonstrating adequate obturation of the three canals in the mesial root. Prior diagnostic knowledge obtained from the 3D image allowed for identification of this canal ...
... lateral extent of the canal morphology prior to treatment. Bottom Middle: 2D image taken after root canal treatment demonstrating adequate obturation of the three canals in the mesial root. Prior diagnostic knowledge obtained from the 3D image allowed for identification of this canal ...
DoseWatch - GE Healthcare
... rejected series may never be sent at all. These scenarios and others can result in under- or over-counting of dose,5 particularly when that data is retrieved from PACS and there is no other available DICOM source for dose information. DoseWatch takes these issues into consideration by not just offer ...
... rejected series may never be sent at all. These scenarios and others can result in under- or over-counting of dose,5 particularly when that data is retrieved from PACS and there is no other available DICOM source for dose information. DoseWatch takes these issues into consideration by not just offer ...
Editorial - European ALARA Network
... patients and staff. These are increasing significantly: the average per caput doses in some European countries from medical exposures is now thought to exceed that from natural sources, which could be regarded as something of a milestone in the evolution of radiation protection. Of course, the benef ...
... patients and staff. These are increasing significantly: the average per caput doses in some European countries from medical exposures is now thought to exceed that from natural sources, which could be regarded as something of a milestone in the evolution of radiation protection. Of course, the benef ...
Chapter_050
... inserted into a photographic printer in the darkroom. The printer stamps the information on the film after it is removed from the cassette and before it is processed. ...
... inserted into a photographic printer in the darkroom. The printer stamps the information on the film after it is removed from the cassette and before it is processed. ...
Chapter_050
... inserted into a photographic printer in the darkroom. The printer stamps the information on the film after it is removed from the cassette and before it is processed. ...
... inserted into a photographic printer in the darkroom. The printer stamps the information on the film after it is removed from the cassette and before it is processed. ...
Fluoroscopy
Fluoroscopy /flɔrˈɒskəpi/ is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope /ˈflɔrɵˌskoʊp/ allows a physician to see the internal structure and function of a patient, so that the pumping action of the heart or the motion of swallowing, for example, can be watched. This is useful for both diagnosis and therapy and occurs in general radiology, interventional radiology, and image-guided surgery. In its simplest form, a fluoroscope consists of an X-ray source and a fluorescent screen, between which a patient is placed. However, since the 1950s most fluoroscopes have included X-ray image intensifiers and cameras as well, to improve the image's visibility and make it available on a remote display screen. For many decades fluoroscopy tended to produce live pictures that were not recorded, but since the 1960s, as technology improved, recording and playback became the norm.Fluoroscopy is similar to radiography and X-ray computed tomography (X-ray CT) in that it generates images using X-rays. The original difference was that radiography fixed still images on film whereas fluoroscopy provided live moving pictures that were not stored. However, today radiography, CT, and fluoroscopy are all digital imaging modes with image analysis software and data storage and retrieval. The use of X-rays, a form of ionizing radiation, requires the potential risks from a procedure to be carefully balanced with the benefits of the procedure to the patient. Because the patient must be exposed to a continuous source of x-rays instead of a momentary pulse, a fluoroscopy procedure generally subjects a patient to a higher absorbed dose of radiation than an ordinary (still) radiograph. Much research has been directed toward reducing radiation exposure, and recent advances in fluoroscopy technology such as digital image processing and flat panel detectors, have resulted in much lower radiation doses than former procedures.The type of fluoroscopy used in airport security (to check for hidden weapons or bombs) uses lower doses of radiation than medical fluoroscopy. It was formerly also used in retail stores in the form of shoe-fitting fluoroscopes, but such use was discontinued because it is no longer considered acceptable to use radiation exposure, however small the dose, for nonessential purposes. Only important applications such as health care, bodily safety, food safety, nondestructive testing, and scientific research meet the risk-benefit threshold for use. The reason for higher doses in medical applications is that they are more demanding about tissue contrast, and for the same reason they sometimes require contrast media.