CT scans

How MRI and CT predict flap failure after head and neck reconstructive cancer surgery

Author: Noah Fromson Source: labblog.uofmhealth.org A composite picture from MR perfusion of a free flap demonstrating measurements made within the flap. Credit: Michigan Medicine When a patient with head and neck cancer has surgery to remove it, they often need reconstructive surgery in the form of a “free flap”, which is skin and tissue taken from a different part of the body and connected to the blood vessels of the wound in need of repair. This free flap method, called microvascular reconstruction, carries around a 10-40% risk of wound complications, with 10% of cases requiring another surgery. A Michigan Medicine study finds that early postoperative CT scans and MRIs can help predict whether a flap will fail, which could allow surgeons to intervene earlier. The results are published in the American Journal of Neuroradiology. “All patients who have this procedure can be investigated with non-invasive post-operative CT or MRI perfusion, and these two methods show a lot of promise as accurate biomarkers of predicting free flap viability,” said Ashok Srinivasan, M.D., FACR, senior author of the paper and neuroradiologist at University of Michigan Health. “By seeing how much blood is flowing in and out of the tissue, we may be able to predict if the flap will succeed and if the patient can be discharged earlier, or it may be able to tell us sooner that surgical intervention is needed to repair the flap. Radiologists have used CT and MRI perfusion with contrast to look at blood perfusion [...]

Oral Cancer Foundation News Team - A2022-06-24T14:02:20-07:00June, 2022|Oral Cancer News|

Experts: CT scans pose risks, need more regulation

Source: news.yahoo.com Author: Marilynn Marchione, AP Medical Writer From long-term cancer risks to radiation overdose mistakes, CT scans pose a growing danger to the American public and need more regulation to improve their safety, imaging experts write in a leading medical journal. The articles in Thursday's New England Journal of Medicine come a week after a story by The Associated Press detailed the overuse of imaging tests and how much the average American's radiation dose has grown in recent years. CT scans are super-sharp X-rays that have transformed medicine by helping doctors quickly diagnose or rule out injuries and diseases. But they use far more radiation than ordinary X-rays, and too much radiation raises the risk of cancer over time. The federal Food and Drug Administration and Congress are considering new measures to help prevent medical mistakes — relatively rare cases where some people are accidentally given radiation overdoses. However, far more people face potential long-term harm from ordinary scans that are done correctly but that are overused, repeated or simply unnecessary. Each year, 10 percent of the U.S. population gets a CT scan, and use of this imaging is growing more than 10 percent per year. "That's really the area we should focus on," said the author of one of the articles, Dr. Rebecca Smith-Bindman. She is a radiologist at the University of California at San Francisco on temporary leave to do radiation research at the National Cancer Institute. The FDA regulates scanning equipment, but lacks authority to say [...]

Oral Cancer Foundation News Team - A2010-06-27T10:30:46-07:00June, 2010|Oral Cancer News|

F.D.A. to increase medical radiation oversight

Source: nytimes.com Authors: Walt Bogdanich & Rebecca R. Ruiz The federal Food and Drug Administration said Tuesday that it would take steps to more stringently regulate three of the most potent forms of medical radiation, including increasingly popular CT scans, some of which deliver the radiation equivalent of 400 chest X-rays. With the announcement, the F.D.A. puts its regulatory muscle behind a growing movement to make life-saving medical radiation — both diagnostic and therapeutic — safer. Last week, the leading radiation oncology association called for enhanced safety measures. And a Congressional committee was set to hear testimony Wednesday on the weak oversight of medical radiation, but the hearing was canceled because of bad weather. The F.D.A. has for weeks been investigating why more than 300 patients in four hospitals were overradiated by powerful CT scans used to detect strokes. The overdoses were first discovered last year at Cedars-Sinai Medical Center in Los Angeles, where patients received up to eight times as much radiation as intended. The errors occurred over 18 months and were detected only after patients lost their hair. In making the announcement, the F.D.A. said it hoped to reduce unnecessary radiation exposure from three medical imaging procedures: CT scans, which provide three-dimensional images; nuclear medicine studies, in which patients are given a radioactive substance and doctors watch it move through the body; and fluoroscopies, in which a radiation-emitting device provides a continuous internal image on a monitor. “These types of imaging exams expose patients to ionizing radiation, a [...]

Oral Cancer Foundation News Team - A2010-02-09T21:34:45-07:00February, 2010|Oral Cancer News|

Radiation exposure may increase risk of stroke and heart disease

Source: www.onmedica.com Author: OnMedica Staff Exposure to moderate levels of radiation may increase the rates of heart disease and stroke, according to new research. Several studies have shown that high doses of radiation to the heart or head and neck from radiotherapy cause an excess of deaths from heart disease or stroke in later years. But it is uncertain whether radiation exposures at relatively low dose levels (under 1 Gy) also increase the risk. To investigate this further, Dr Yukiko Shimizu and colleagues from the Radiation Effects Research Foundation in Japan examined the risk of heart disease and stroke in 86,611 atomic bomb survivors from Hiroshima and Nagasaki who have been followed up for 53 years, from 1950 to 2003, as part of the Japanese atomic bomb survivor Life Span Study. Each member of the group had received an estimated radiation dose from 0-4 Gy (86% received less than 0.2 Gy) at the time of the bomb. Other risk factors for circulatory disease that could have affected the results, such as smoking, alcohol intake, education, occupation, obesity and diabetes were also taken into account. The researchers found an elevated risk of both stroke and heart disease at doses above 0.5 Gy, but the degree of risk at lower doses was unclear. Together, this represents about 210 excess deaths from circulatory disease associated with radiation exposure – about a third as many as the total excess number of cancer deaths (about 625) among atomic bomb survivors in the Life Span Study. [...]

Oral Cancer Foundation News Team - A2010-01-15T19:58:54-07:00January, 2010|Oral Cancer News|

Study cites radiation risk from CT scans

Source: nytimes.com Author: staff Radiation from CT scans done in 2007 will cause 29,000 cancers and kill nearly 15,000 Americans, researchers said Monday. The findings, published in the Archives of Internal Medicine, add to mounting evidence that Americans are overexposed to radiation from diagnostic tests, especially from a specialized kind of X-ray called a computed tomography, or CT, scan. "What we learned is there is a significant amount of radiation with these CT scans, more than what we thought, and there is a significant number of cancers," said Dr. Rita Redberg, editor of the Archives of Internal Medicine, where the studies were published. "It's estimated that just from the CT scans done in one year, just in 2007, there will be 15,000 excess deaths," Redberg said in a telephone interview. "We're doing millions of CT scans every year and the numbers are increasing. That is a lot of excess deaths." CT scans give doctors a view inside the body, often eliminating the need for exploratory surgery. But CT scans involve much higher radiation dose than conventional X-rays. A chest CT scan exposes the patient to more than 100 times the radiation dose of a chest X-ray. About 70 million CT scans were done on Americans in 2007, up from 3 million in 1980. Amy Berrington de Gonzalez of the National Cancer Institute and colleagues developed a computer model to estimate the impact of so many scans. They estimated the scans done in 2007 will cause 29,000 cancers. A third of [...]

Oral Cancer Foundation News Team - A2009-12-15T21:58:15-07:00December, 2009|Oral Cancer News|