• Study Resource
  • Explore
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
Imaging the posterior mediastinum: a multimodality approach
Imaging the posterior mediastinum: a multimodality approach

... on both T1- and T2-weighted MRI. Inactive lesions have low or high attenuation values on CT, depending on the presence of fat or the iron content of the masses (Fig. 4). For the same reason, inactive lesions have high-signal intensity on both T1- and T2-weighted images if there is fatty replacement ...
Gold Nanoparticle Contrast Agents in Advanced X
Gold Nanoparticle Contrast Agents in Advanced X

... in biological tissues. High-energy (80 MeV) synchrotron sources first became available in the 1940s [11]. The accelerator-based strategy results in small source size, small angular divergence and high power sources, which cannot be provided by the standard Röntgen mechanism, even though they are req ...
The effectiveness of Power Doppler vocal fremitus imaging in the
The effectiveness of Power Doppler vocal fremitus imaging in the

... compressibility is another sonographic feature of breast hamartomas [5,13]. Such a wide spectrum of US appearances restricts the role of US in making the diagnosis of the hamartoma [2,3]. Park et al [13] found that 87.5% of hamartomas had a heterogeneous internal echo structure, and suggested that t ...
Gradual transition
Gradual transition

... competition between two different specialist fields and training does not therefore arise. One particular area, which may partly be referred to as horizontal task sharing, is where ultrasound has been taken into use in pregnancy supervision, both by general practitioners and midwives. This was cont ...
Breast Microcalcifications - Diagnostic Centers of America
Breast Microcalcifications - Diagnostic Centers of America

... condition(s). These criteria are intended to guide radiologists, radiation oncologists, and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient's clinical condition should dictate the selection of appropriate imagin ...
Detection of Coronary Artery Stenoses by Contrast
Detection of Coronary Artery Stenoses by Contrast

... side branches, in the analysis if the vessel diameter measured ⱖ2.0 mm. This approach was chosen because to be clinically useful, a noninvasive method must be able to reliably rule out coronary artery stenoses in all arteries that would be potential targets of revascularization therapy. Stenoses in ...
(MRI) of the Soft - American College of Radiology
(MRI) of the Soft - American College of Radiology

... not intended, nor should they be used, to establish a legal standard of care1. For these reasons and those set forth below, the American College of Radiology and our collaborating medical specialty societies caution against the use of these documents in litigation in which the clinical decisions of ...
MIRD Pamphlet No. 23: Quantitative SPECT for Patient
MIRD Pamphlet No. 23: Quantitative SPECT for Patient

... Most dosimetric calculations in internal radionuclide therapy have relied on conjugate-view (anterior–posterior) planar imaging and geometric mean attenuation compensation for activity quantification, as described in MIRD pamphlet no. 16 (5). The planar method, however, cannot resolve the source dep ...
Evaluation of Parotid Gland Function using Equivalent - J
Evaluation of Parotid Gland Function using Equivalent - J

... Roesink et al. found a significant correlation between salivary excretion factor (defined as the percentage of activity in the parotid gland that disappeared within 15 min following administration of carbachol) and mean radiation dose to the parotid glands.3) However, in our research, WOR did not sh ...
ACR–ASNR–SCBT-MR Practice Parameter for the Performance of
ACR–ASNR–SCBT-MR Practice Parameter for the Performance of

... The American College of Radiology, with more than 30,000 members, is the principal organization of radiologists, radiation oncologists, and clinical medical physicists in the United States. The College is a nonprofit professional society whose primary purposes are to advance the science of radiology ...
ACR–ASNR–SCBT-MR Practice Parameter for the Performance of
ACR–ASNR–SCBT-MR Practice Parameter for the Performance of

... The American College of Radiology, with more than 30,000 members, is the principal organization of radiologists, radiation oncologists, and clinical medical physicists in the United States. The College is a nonprofit professional society whose primary purposes are to advance the science of radiology ...
Competencies - sri lanka school of radiography
Competencies - sri lanka school of radiography

... The sections that can be taught together are typed in ‘bold’ or marked with an asterisk (*) The diagnostic radiography course is organized to develop relevant competencies by providing alternate blocks (subjects) of study at the School of Radiography, with practical placements in various x-ray/imagi ...
A Cone-Beam Volume CT Using a 3D Angiography System with a
A Cone-Beam Volume CT Using a 3D Angiography System with a

... and timing of acquisition and scanning delay), and superselective intra-arterial chemotherapy protocol are summarized in Table 1. The DSA and rotational angiography were successfully performed in all 23 of the patients (a total of 43 arteries: 4 arteries in 1 patient, 3 arteries in 5 patients, 2 art ...
Quantitative Methods for Tumor Imaging with Dynamic PET
Quantitative Methods for Tumor Imaging with Dynamic PET

... prediction and monitoring of treatment response [11]. Since the introduction of PET in cancer care (mainly using the tracer 2-deoxy-2-(18 F)fluoro-D-glucose [18 F-FDG]), it has been shown to improve the accuracy of detection and staging of several cancers [16]. By including PET data in the work-ups, ...
Cross Sectional Imaging Nuclear Medicine
Cross Sectional Imaging Nuclear Medicine

... • No superimposition of structures • Excellent contrast resolution – can see the difference between 2 similar tissues • For CT – scan can be performed in one plane (usually transverse) and reformatted in the others (sag, dorsal) • CT – good for bone and soft tissue • MRI – better for soft tissue www ...
Brain perfusion imaging: How does it work and what should I use?
Brain perfusion imaging: How does it work and what should I use?

... date. Furthermore, there is no uniformity among methods used in practice, most of which have not been thoroughly validated (13,14). As such, the difficultly in performing accurate and reproducible absolute perfusion quantification using DSC techniques is one of the primary weaknesses of this method, ...
Absolute quantification in SPECT
Absolute quantification in SPECT

... assumed that the decay takes place exactly perpendicular to the detection plane and detection location. For the detected scatter quanta, because of the change in direction, not only the distance between the decay and the location of detection along the LOR is unknown, but also the correct position o ...
Radiological Protection in Cone Beam Computed Tomography
Radiological Protection in Cone Beam Computed Tomography

... that have potential for technological developments for safer technology. In this manner the ICRP has acted as an important resource presaging safety issues based on current and future usage of technology and identifying the needs where technology can contribute. Of course there are vast areas of opt ...
Numbness matters: A clinical review of trigeminal neuropathy
Numbness matters: A clinical review of trigeminal neuropathy

... observed in TNA and this aspect of the clinical exam may have a limited utility in distinguishing the two disorders, unless it reveals cutaneous or intraoral trigger for pain, which would increase the likelihood of TNA. The predictive value of clinical neurosensory testing has some limitations and m ...
Workshop on "X-ray Science with Coherent Radiation"
Workshop on "X-ray Science with Coherent Radiation"

... Linac based x-ray sources: temporal & spatial coherence ............................................... Tutorial: Coherence in x-ray physics ................................................................................ X-ray intensity correlation spectroscopy ..................................... ...
radiation protection in diagnostic radiology - RPOP
radiation protection in diagnostic radiology - RPOP

... results in lower doses • X Ray rooms for pediatrics should be designed for improving the child’s cooperation (control panel within easy reach, etc.) • Fast screen-film combinations or digital radiography have advantages (reduction of dose) and limitations • Low-absorbing materials in cassettes, tabl ...
May 2011 - American College of Radiology
May 2011 - American College of Radiology

... (MPPR) to the physician work component (of the Physician Fee Schedule) in addition to the technical component. The ACR does not believe that Congress should be directed to apply the MPPR to the physician work component. In fact, there is no justification to apply MPPR to the physician work component ...
Public Summary Document - Word 93 KB
Public Summary Document - Word 93 KB

... MSAC questioned bulk billing rates and patient co-payments for the interim listed CBCT items. The policy area was not able to comment during the course of the meeting, but have subsequently advised that in 2012/13 the bulk billing rate for the interim items is 60% and the average patient co-payment ...
Positron emission tomographic imaging with 11C
Positron emission tomographic imaging with 11C

... 11C-labeled choline (CHOL) for the differential diagnosis of malignant head and neck tumors from benign lesions as compared with 18F-fluorodeoxyglucose PET. Methods: We studied 45 patients (28 males, 17 females, age range, 29–84 years) with suspected lesions in the head and neck region using both CH ...
Sir Godfrey Newbold Hounsfield KT CBE. 28 August 1919
Sir Godfrey Newbold Hounsfield KT CBE. 28 August 1919

... arranged it to rotate a collimated -ray source (americium-241) through about 1° every time it traversed an object. The objects that he tried were bottles and bits of Perspex. After nine days of scanning, he could obtain a sufficient number of readings to reconstruct a single image—a process that oc ...
< 1 2 3 4 5 6 7 8 ... 78 >

Radiosurgery

Radiosurgery is surgery using radiation, that is, the destruction of precisely selected areas of tissue using ionizing radiation rather than excision with a blade. Like other forms of radiation therapy, it is usually used to treat cancer. Radiosurgery was originally defined by the Swedish neurosurgeon Lars Leksell as “a single high dose fraction of radiation, stereotactically directed to an intracranial region of interest”. In stereotactic radiosurgery (SRS), the word stereotactic refers to a three-dimensional coordinate system that enables accurate correlation of a virtual target seen in the patient's diagnostic images with the actual target position in the patient anatomy.Technological improvements in medical imaging and computing have led to increased clinical adoption of stereotactic radiosurgery and have broadened its scope in recent years. Notwithstanding these improvements, the localization accuracy and precision that are implicit in the word “stereotactic” remain of utmost importance for radiosurgical interventions today. Stereotactic accuracy and precision are significantly increased by using a device known as the N-localizer that was invented by the American physician and computer scientist Russell Brown and that has achieved widespread clinical use in several stereotactic surgical and radiosurgical systems.Recently, the original concept of radiosurgery has been expanded to include treatments comprising up to five fractions, and stereotactic radiosurgery has been redefined as a distinct neurosurgical discipline that utilizes externally generated ionizing radiation to inactivate or eradicate defined targets in the head or spine without the need for a surgical incision. Irrespective of the similarities between the concepts of stereotactic radiosurgery and fractionated radiotherapy, and although both treatment modalities are reported to have identical outcomes for certain indications, the intent of both approaches is fundamentally different. The aim of stereotactic radiosurgery is to destroy target tissue while preserving adjacent normal tissue, where fractionated radiotherapy relies on a different sensitivity of the target and the surrounding normal tissue to the total accumulated radiation dose. Historically, the field of fractionated radiotherapy evolved from the original concept of stereotactic radiosurgery following discovery of the principles of radiobiology: repair, reassortment, repopulation, and reoxygenation. Today, both treatment techniques are complementary as tumors that may be resistant to fractionated radiotherapy may respond well to radiosurgery and tumors that are too large or too close to critical organs for safe radiosurgery may be suitable candidates for fractionated radiotherapy.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report