AAPM Imaging Physics Curricula Subcommittee
... for teaching residents as well as for resident self-education. The questions are not based on recalls of old American Board of Radiology examination questions. Any similarity with the past or current ABR examination is purely coincidental. This curriculum contains 15 modules covering imaging physics ...
... for teaching residents as well as for resident self-education. The questions are not based on recalls of old American Board of Radiology examination questions. Any similarity with the past or current ABR examination is purely coincidental. This curriculum contains 15 modules covering imaging physics ...
Managing Patient Dose in Multi-Detector Computed Tomography
... There is lack of consensus on how image quality is to be specified; with the result that there are significant differences in the ways different companies achieve exposure control. It is important that users are aware of the behaviour of their system. “One-size-fits-all” type protocols must not be u ...
... There is lack of consensus on how image quality is to be specified; with the result that there are significant differences in the ways different companies achieve exposure control. It is important that users are aware of the behaviour of their system. “One-size-fits-all” type protocols must not be u ...
Using Cone Beam CT in Clinical Practice
... Another major difference between CBCT and MDCT imaging technologies is the radiation dose required. Effective dose is a term used to describe the relative risk of exposures to ionizing radiation and is calculated in microSieverts (μSv). Standard MDCT images of the maxillofacial region result in radi ...
... Another major difference between CBCT and MDCT imaging technologies is the radiation dose required. Effective dose is a term used to describe the relative risk of exposures to ionizing radiation and is calculated in microSieverts (μSv). Standard MDCT images of the maxillofacial region result in radi ...
Patient Dose in common CT examinations-2003
... Since the discovery of X rays and radioactivity more than 100 years ago, different ways of producing radiation and radioactive materials artificially have been found. The first use of X rays was in medical diagnosis, within six months of their discovery in 1895. Diagnostic radiology is concerned wit ...
... Since the discovery of X rays and radioactivity more than 100 years ago, different ways of producing radiation and radioactive materials artificially have been found. The first use of X rays was in medical diagnosis, within six months of their discovery in 1895. Diagnostic radiology is concerned wit ...
A Study on Evaluation of kV-CBCT-image-based Treatment
... CBCT based on flat-panel technology integrated in a medical linear accelerator has improved the precision of targeting in radiotherapy. Two important applications of CBCT are patient setup and dose verification. A CBCT image of the patient on the treatment table can be acquired in about 60 seconds, ...
... CBCT based on flat-panel technology integrated in a medical linear accelerator has improved the precision of targeting in radiotherapy. Two important applications of CBCT are patient setup and dose verification. A CBCT image of the patient on the treatment table can be acquired in about 60 seconds, ...
Evaluation and Validation of Computed Tomography Dose Accuracy
... using two different devices and techniques. The Barracuda electrometer and Ion Chamber techniques were applied on a 16 slice Siemens CT scanner and the results compared to the console displayed CTDIw and CTDIvol valuesfor accuracy and compared to each other for validation purposes. With fixed exposu ...
... using two different devices and techniques. The Barracuda electrometer and Ion Chamber techniques were applied on a 16 slice Siemens CT scanner and the results compared to the console displayed CTDIw and CTDIvol valuesfor accuracy and compared to each other for validation purposes. With fixed exposu ...
code of safe practice for the use of
... controls shall be such that occupational doses are significantly below the dose limits for radiation personnel (see paras 3.2, 3.3, 3.4 and 3.5) . This will normally require a protective barrier at the x-ray controls. (See para 6.2) 3.12 A protective apron of lead equivalence not less than 0.25 mm s ...
... controls shall be such that occupational doses are significantly below the dose limits for radiation personnel (see paras 3.2, 3.3, 3.4 and 3.5) . This will normally require a protective barrier at the x-ray controls. (See para 6.2) 3.12 A protective apron of lead equivalence not less than 0.25 mm s ...
International Workshop on Monte Carlo Techniques in Medical
... artificial implants from CAD modeling (screws, hip replacements, brachytherapy seeds, etc) or anatomical details extracted from other imaging modalities, such as for example MRI (arteries, spinal cord, atheroma, etc). A potential solution based on the use of smaller voxels for modeling complex objec ...
... artificial implants from CAD modeling (screws, hip replacements, brachytherapy seeds, etc) or anatomical details extracted from other imaging modalities, such as for example MRI (arteries, spinal cord, atheroma, etc). A potential solution based on the use of smaller voxels for modeling complex objec ...
radiation medicine qa
... Contrary to the many positive aspects, the major drawback of ionizing radiation is the radiation risk. When irradiated, healthy human tissue can be damaged. The higher the radiation load to a person, the higher is the risk for the development of diseases. In the case of intended irradiation of patie ...
... Contrary to the many positive aspects, the major drawback of ionizing radiation is the radiation risk. When irradiated, healthy human tissue can be damaged. The higher the radiation load to a person, the higher is the risk for the development of diseases. In the case of intended irradiation of patie ...
19 2D and 3D Planning in Brachytherapy
... A common procedure, at least in the past for gynaecological and other intracavitary applications, was based on two or more X-ray films, which are mainly used for the 3D reconstruction of the used catheters or applicators. For the intracavitary brachytherapy of the primary cervix carcinoma a set of di ...
... A common procedure, at least in the past for gynaecological and other intracavitary applications, was based on two or more X-ray films, which are mainly used for the 3D reconstruction of the used catheters or applicators. For the intracavitary brachytherapy of the primary cervix carcinoma a set of di ...
Technical assessment of a cone-beam CT scanner
... (FDK) algorithm1 for 3D filtered backprojection, although CBCT will similarly benefit from advances in iterative reconstruction techniques and low-dose protocols.2 The scope of application-specific CBCT embodiments include dental/maxillofacial imaging,3–13 temporal bone imaging,14–16 breast imaging, ...
... (FDK) algorithm1 for 3D filtered backprojection, although CBCT will similarly benefit from advances in iterative reconstruction techniques and low-dose protocols.2 The scope of application-specific CBCT embodiments include dental/maxillofacial imaging,3–13 temporal bone imaging,14–16 breast imaging, ...
The management of imaging dose during image-guided
... published 26 September 2007兲 Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality and method, all radiographic guidance techniques have one thing in common—they can gi ...
... published 26 September 2007兲 Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality and method, all radiographic guidance techniques have one thing in common—they can gi ...
Imaging dose from cone beam computed tomography in radiation
... The patient studies generally employed TLDs or other dosimeters to measure skin dose [20e22,27,45] although there have been two studies measuring the dose inside the rectum [46,47]. Patient dose measurements are summarized in Table 2. The skin dose measurements range from fraction of a cGy (for low ...
... The patient studies generally employed TLDs or other dosimeters to measure skin dose [20e22,27,45] although there have been two studies measuring the dose inside the rectum [46,47]. Patient dose measurements are summarized in Table 2. The skin dose measurements range from fraction of a cGy (for low ...
IMRT verification by three-dimensional dose reconstruction
... The small size of the detector (20 cm⫻20 cm) limits this study to small phantoms and a small target volume, although the method described is readily applicable to larger detectors. Since the entire object must be visible in every projection for good quality CT reconstructions, the detector was mount ...
... The small size of the detector (20 cm⫻20 cm) limits this study to small phantoms and a small target volume, although the method described is readily applicable to larger detectors. Since the entire object must be visible in every projection for good quality CT reconstructions, the detector was mount ...
The possibilities of reducing radiation dose and improve image
... The organ doses from CT examinations including two or more scan series yields radiation doses above the threshold of 100 mSv. Between 1.5 and 2% of all cancers might be related to radiation from CT examinations6. In the UK about 700 cases of cancer annually is assumed attributed to diagnostic X-ray ...
... The organ doses from CT examinations including two or more scan series yields radiation doses above the threshold of 100 mSv. Between 1.5 and 2% of all cancers might be related to radiation from CT examinations6. In the UK about 700 cases of cancer annually is assumed attributed to diagnostic X-ray ...
Evaluation of the Three Dimensional Localization
... mm. With the dosimetric accuracy of treatment delivery, the average minimum dose, mean dose, and maximum dose in PTV of the original plans and the CBCT-based plans were 95.45% ± 3.80% and 92.88% ± 3.25%, 110.59% ± 1.81% and 110.11%±2.40%, 116.55%±3.11% and 115.93%±2.78%, respectively. In the origin ...
... mm. With the dosimetric accuracy of treatment delivery, the average minimum dose, mean dose, and maximum dose in PTV of the original plans and the CBCT-based plans were 95.45% ± 3.80% and 92.88% ± 3.25%, 110.59% ± 1.81% and 110.11%±2.40%, 116.55%±3.11% and 115.93%±2.78%, respectively. In the origin ...
Radiation therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is therapy using ionizing radiation, generally as part of cancer treatment to control or kill malignant cells. Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body. It may also be used as part of adjuvant therapy, to prevent tumor recurrence after surgery to remove a primary malignant tumor (for example, early stages of breast cancer). Radiation therapy is synergistic with chemotherapy, and has been used before, during, and after chemotherapy in susceptible cancers. The subspecialty of oncology that focuses on radiotherapy is called radiation oncology.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing radiation works by damaging the DNA of cancerous tissue leading to cellular death. To spare normal tissues (such as skin or organs which radiation must pass through to treat the tumor), shaped radiation beams are aimed from several angles of exposure to intersect at the tumor, providing a much larger absorbed dose there than in the surrounding, healthy tissue. Besides the tumour itself, the radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with tumor, or if there is thought to be a risk of subclinical malignant spread. It is necessary to include a margin of normal tissue around the tumor to allow for uncertainties in daily set-up and internal tumor motion. These uncertainties can be caused by internal movement (for example, respiration and bladder filling) and movement of external skin marks relative to the tumor position.Radiation oncology is the medical specialty concerned with prescribing radiation, and is distinct from radiology, the use of radiation in medical imaging and diagnosis. Radiation may be prescribed by a radiation oncologist with intent to cure (""curative"") or for adjuvant therapy. It may also be used as palliative treatment (where cure is not possible and the aim is for local disease control or symptomatic relief) or as therapeutic treatment (where the therapy has survival benefit and it can be curative). It is also common to combine radiation therapy with surgery, chemotherapy, hormone therapy, immunotherapy or some mixture of the four. Most common cancer types can be treated with radiation therapy in some way.The precise treatment intent (curative, adjuvant, neoadjuvant, therapeutic, or palliative) will depend on the tumor type, location, and stage, as well as the general health of the patient. Total body irradiation (TBI) is a radiation therapy technique used to prepare the body to receive a bone marrow transplant. Brachytherapy, in which a radiation source is placed inside or next to the area requiring treatment, is another form of radiation therapy that minimizes exposure to healthy tissue during procedures to treat cancers of the breast, prostate and other organs.Radiation therapy has several applications in non-malignant conditions, such as the treatment of trigeminal neuralgia, acoustic neuromas, severe thyroid eye disease, pterygium, pigmented villonodular synovitis, and prevention of keloid scar growth, vascular restenosis, and heterotopic ossification. The use of radiation therapy in non-malignant conditions is limited partly by worries about the risk of radiation-induced cancers.