Radiology - Technology Information Portal
Friday, 29 March 2024
• Welcome to Radiology-TIP.com!
     • Sign in / Create account
 
 'RIS' 
SEARCH   
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
Searchterm 'RIS' found in 2 terms [
] and 46 definitions [
]
Result Pages :
RIS
See Radiology Information System.
• 
View NEWS results for 'RIS' (17).Open this link in a new window.
Dosimetrist
Dosimetrists calculate the dose of radiation. To secure sufficient tumor destruction while sparing the normal tissues, a number of (often) complex treatment plans are developed.
The Medical Dosimetrist Certification Board certifies dosimetrists. Dosimetrists work with the physician and the medical physicist to choose the treatment plan that is best for each patient. A dosimetrist may start as a radiation therapist and become with intensive training a dosimetrist. Others are graduates of dosimetry programs.
Bone Densitometry
Bone densitometry measures the strength and density of bones. Changes in trabecular bone mineral density (BMD) is an early indicator of change in metabolic function. Bone densitometry measures the amount of calcium in regions of the bones. A bone densitometer is used to determine the risk of developing osteoporosis and can also be used to estimate a patient's risk of fracture.
Bone densitometry methods involve:
Dual energy x-ray absorptiometry (DEXA - used to measure the spine, hip or total body);
single energy x-ray absorptiometry (SXA - measures the wrist or heel);
peripheral dual energy x-ray absorptiometry (PDXA - used to measure the wrist, heel or finger bones);
osteo CT or quantitative computed tomography (QCT - used to measure the spine or hip);
dual photon absorptiometry (DPA - measures the spine, hip or total body);
single photon absorptiometry (SPA - measures the wrist);
ultrasound densitometry (measures the heel).

Dual energy x-rays (DEXA) or CT scans (Osteo CT or QCT) compare the numerical density of the bone (calculated from the image), with empirical data bases of bone density. DEXA is widely available and has an accuracy between those of QCT and ultrasound.
Low-Osmolar Contrast Media
(LOCM) Low-osmolar contrast media have a wide range of indications due to their lower side effects. The type of contrast media is an important risk factor for an adverse reaction.
LOCM have not completely replaced contrast media with higher osmolality due to their higher cost. Guidelines of professional organizations give recommendations for the selective use of low-osmolar contrast media for certain high-risk patients.
There are ionic and nonionic iodinated contrast materials with low osmolality available:
nonionic dimer.
An adverse reaction occurs in low-risk patients who receive conventional ionic contrast agents more often than in high-risk patients who receive nonionic LOCM.

See also Contrast Enhancement, Biliary Contrast Agents, Safety of Contrast Agents and Contrast-Induced Nephropathy.
Iodide-Induced Hyperthyroidism
Iodinated contrast media contain small amounts of free iodide. Too much free iodide in the blood may cause hyperthyroidism in patients at risk, but contrast medium induced thyrotoxicosis is rare. The free iodide may also interfere with nuclear medicine diagnostic tests and treatment. However, iodinated contrast agents do not affect thyroid function tests (e.g., T3, T4, TSH) in patients with a normal thyroid.
Guidelines were prepared by the 'Contrast Media Safety Committee of the European Society of Urogenital Radiology' and discussed on the Tenth European Symposium on Urogenital Radiology in September 2003.
Tests of thyroid function before the injection of contrast agents may only be indicated in areas with dietary iodine deficiency. Patients with Graves' disease, multinodular goiter with thyroid autonomy, especially elderly and patients who lives in areas of iodine deficiency are at risk to develop thyrotoxicosis after IV contrast medium and should be monitored by endocrinologists after contrast enhanced CT exams. Prophylaxis may offer some protection in selected high-risk individuals but is not generally recommended.
The free iodide of iodinated contrast agents interferes with thyroidal iodide uptake and impedes diagnostic thyroid scintigraphy and radio-iodine treatment of thyroid malignancies for 2 months after administration.
Result Pages :
 
Share This Page
Facebook
Twitter
LinkedIn

Look
      Ups
Radiology - Technology Information Portal
Member of SoftWays' Medical Imaging Group - MR-TIP • Radiology-TIP • Medical-Ultrasound-Imaging
Copyright © 2008 - 2024 SoftWays. All rights reserved.
Terms of Use | Privacy Policy | Advertising
 [last update: 2023-11-06 02:01:00]