Navigation Links
Halving the radiation dose in cardiac perfusion imaging is now 'feasible'
Date:5/17/2011

17 May 2011 -- A reduction by half in the radiation dose to which cardiac patients are exposed during diagnostic perfusion imaging is now "feasible", according to an Israeli study.

Results from the study will be presented as a late-breaking trial at the International Conference of Non-Invasive Cardiovascular Imaging (ICNC) in Amsterdam (15-18 May). ICNC is now one of the world's major scientific events in nuclear cardiology and cardiac CT imaging.

The various modalities of modern perfusion imaging - such as single photon emission computed tomography (SPECT) - allow the non-invasive assessment of myocardial blood flow and thus the detection of coronary artery disease. The cardiac imaging test is usually performed twice to provide a comparison between at rest and at exercise ("rest-stress", and vice-vera). Blood flow can be scanned and visualised because of an injection of radioisotope tracer (technetium sestamibi) which enters through the coronary blood vessels and is distributed into the myocardium ("perfusion"); the images are based on gamma rays given off by the tracer substance. Healthy functional myocardial tissue will absorb the radioactive material. However, in cases of reduced blood flow (because of coronary artery narrowing) perfusion defects will be seen. This denotes "myocardial ischaemia", which occurs following exercise. When there is damaged tissue (infarct), fixed defects will also be seen at rest imaging.

According to Professor Nili Zafrir, Director of Nuclear Cardiology at the Rabin Medical Center in Petah Tikva, Israel, and first author of this late-breaking study, the current application of standard myocardial perfusion diagnosis is "limited" because of "high radiation dose" in the tracer substance with which each patient is injected. She agrees that the radiation dose is within acceptable limits, but insists that the level of radiation exposure (and its consequent cancer risk) is still a matter of great debate. The present study was designed to test whether radiation dose could be reduced without loss of resolution in the diagnostic images.

Radiation effective dose is measured in millisieverts, and, with conventional protocols, each investigation exposes the patient to a radiation dose of between 8 and 25 mSv. This study compared outcome from two protocols, a conventional full dose injection of tracer substance and a half-dose injection. Each group comprised 109 patients, who were investigated with stress-only, rest-and-stress and stress-and rest imaging. The full dose protocol was applied with dosages ranging between 12 and 32 milicurries (mCi) (depending on patient weight); in the half dose protocol dosages ranged between 5 and 17 mSCi. These were converted to radiation effective dose (in mSv).

Professor Zafrir explains that the study only became possible because of the introduction of new image processing software, which was originally designed to reduce the time it takes to acquire a full diagnostic image. " The aim of our study," she says, "was to use the same software but to assess the feasibility of reducing the tracer dose instead of reducing the acquisition time."

Results showed that 94% of the images from the half-dose protocol were assessed as "excellent to good", suggesting no loss of image quality or diagnostic accuracy when the radiation dose of the perfusion was halved.

Professor Zafrir also reports that 35% of the patients in the half-dose group had only a single stress-only investigation, and they were exposed to a mean of just 1.9 mSv. The total effective dose for stress-rest investigation was 7.19 mSv in the half dose protocol compared to 14.4 mSv in the conventional dose protocol.

"So it's our view that myocardial perfusion imaging is feasible with significant radiation dose reduction," says Professor Zafrir. "We found that image quality using the new processing software was similar to that in conventional protocols. Indeed, the clinical results identified with the half-does protocol were equivalent to those determined by full dose imaging. But significantly, the half dose protocol reduced radiation exposure to a minimum of 1.9 mSv in one-third of our patients, far below the dose range we see in conventional perfusion scanning.

"Clearly, we cannot be certain what the long-term benefit of reducing radiation exposure might be, but theoretically it would seem important."


'/>"/>

Contact: Jacqueline Partarrieu
press@escardio.org
33-492-947-756
European Society of Cardiology
Source:Eurekalert

Related medicine news :

1. Thomas Jefferson University and hospitals tasked to find new radiation drugs
2. Low-dose chest CT effective in reducing radiation for evaluation of cardiothoracic surgery patients
3. Study says eliminate pelvic imaging to reduce radiation for the detection of venous thromboembolism
4. Breast Cancer Recurrence Rates Appear Different When Radiation Used
5. Proton imaging provides more accuracy, less radiation to pediatric cancer patients
6. Managing Chemoradiation Side Effects May Prolong Survival
7. Society of Interventional Radiology addresses radiation safety, advances best practices
8. Minimizing side effects from chemoradiation could help brain cancer patients live longer
9. Japanese Radiation Called No Threat to North American Fish Fans
10. Radiation at time of lumpectomy may offer faster, more precise treatment for breast cancer patients
11. New radiation treatment practice recommendations for thyroid disease
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/7/2016)... Arizona (PRWEB) , ... December 07, 2016 , ... Delete® ... Just in Time For The Holiday Party Season. Save Up To 33% Off Botox® ... Laser Salon is providing the Phoenix Valley with Delightful Deals on Botox® ...
(Date:12/7/2016)... ... , ... The medical profession is well aware that heart attacks do indeed ... heart attacks among 138,602 people recorded a 35% higher number of heart attacks in ... of course–no time of year is a good time for a heart attack! In ...
(Date:12/7/2016)... ... December 07, 2016 , ... ... medicine device WellnessPro Plus for consumers and healthcare professionals to manage chronic ... by expanding the treatment modalities available in a single device. The announcement ...
(Date:12/7/2016)... ... 07, 2016 , ... “Tomorrow Trump Goes To Washington”: a brief but ... presidency and to America. “Tomorrow Trump Goes To Washington” is the creation of published ... for this country. , Nancy attributes her patriotic nature to her WWII veteran father. ...
(Date:12/7/2016)... ... (PRWEB) December 07, 2016 , ... ... individuals impacted by cerebral cavernous angiomas, was awarded a grant from the Julian ... engagement program. New Mexico has more people with cavernous angioma than anywhere in ...
Breaking Medicine News(10 mins):
(Date:12/6/2016)... Homozygous Familial Hypercholesterolemia (HoFH) - ... Global Markets Direct,s latest Pharmaceutical and Healthcare ... – Pipeline Review, H2 2016, provides an ... (Metabolic Disorders) pipeline landscape. Homozygous familial ... caused due to mutation from both parents. ...
(Date:12/6/2016)... The pen needles market is projected to reach USD ... 2016, growing at a CAGR of 11.2% during the ... years, the pen needles market has witnessed various technological ... for safety injections in the healthcare industry. These advancements ... with an aim to reduce pain, increase comfort, and ...
(Date:12/6/2016)... 2016   AlloSource , one of the ... and soft-tissue allografts for use in surgical procedures, ... for being named to the Board of Examiners ... by the Commerce Department,s National Institute of Standards ... process excellence. The Baldrige Award is the nation,s ...
Breaking Medicine Technology: