Медицина

МРТ суставов

Значение магнитно-резонансной томографии (МРТ) в диагностике патологии суставов очень высоко.

Для проведения магнитно-резонансной томографии (МРТ) суставов используются радиоволны и сильное магнитное излучение, которые позволяют получить четкое изображение различных внутренних органов и тканей.

Поскольку МРТ позволяет получить очень четкую картину преимущественно мягких тканей, расположенных вокруг костей, то она часто используется при исследовании крупных суставов (коленных, плечевых и др.), позвоночника и межпозвонковых дисков, мягких тканей конечностей. МРТ широко используется для диагностики спортивной и профессиональной травмы.

Кроме того, МРТ позволяет получить картину дегенеративных заболеваний суставов, например, хронических артритов, повреждений суставных поверхностей, грыж межпозвонковых дисков. Даже небольшие разрывы сухожилий, связок и мышц, а также переломы, не видимые на обычных рентгенограммах, можно диагностировать с помощью МРТ.

По сравнению с другими диагностическими методами исследования МРТ характеризуется самой высокой чувствительностью и достоверностью получаемого изображения. Ее использование позволяет отказаться от инвазивной диагностики (биопсия) или измерения внутрикостного давления. Чувствительность и достоверность изображения, получаемого при МРТ, составляет более 95 %.

 Этот метод исследования гораздо более чувствителен, чем рентгенография и ультразвуковая диагностика. В целом, в отличие от других методов визуализации, с помощью МРТ значительно легче различить здоровую и пораженную ткань.

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Приказ № 469 "О раскреплении лечебно - профилактических учреждений города для направления на рентгеновскую компьютерную и магнитно - резонансную томографию (МРТ)"

В связи с изменениями в материально - техническом обеспечении лечебно - профилактических учреждений Комитета здравоохранения рентгеновским компьютерным и магнитно - резонансным оборудованием
ПРИКАЗЫВАЮ:
1. Утвердить реестры раскрепления лечебно - профилактических учреждений города для направления:
1.1. на рентгеновскую компьютерную томографию (приложение 1);
1.2. на магнитно - томографические исследования (приложение 2).
2.1. Начальникам управлений здравоохранения административных округов, главным врачам лечебно - профилактических учреждений городского подчинения обеспечить обоснованное направление пациентов, нуждающихся в рентгеновской компьютерной и магнитно - резонансной томографии с указанием локализованной анатомической зоны исследования.
3. Начальникам управлений здравоохранения административных округов направлять пациентов на исследования в лечебно - профилактические учреждения, указанные в реестрах (приложения 1 и 2), после рассмотрения медицинской документации главным специалистом округа по лучевой диагностике.
4. Директору НПЦ медицинской радиологии Варшавскому Ю.В. в случаях выхода из строя рентгеновских компьютерных и магнитно - резонансных томографов осуществлять временное перераспределение лечебно - профилактических учреждений города.
5. Считать утратившими силу приказы Комитета здравоохранения от 18.06.2001 N 244 и от 04.11.2000. N 451.
6. Контроль за исполнением настоящего приказа возложить на заместителя председателя Комитета Лешкевича И.А.

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Safer Scans for Pregnant Women

MRI Can Replace CT Scans, Reducing Cancer Risks

Science Daily New studies by radiologists have shown that MRI can be just as accurate as CT scans at helping radiologists diagnose pathologies such as cancer, cysts and kidney stones -- while carrying less risk, especially for pregnant women. The magnetic waves and radiofrequency energy used in MRI are a safer alternative to the potentially carcinogenic X-rays of CT scans, especially during gestation. CT scans are still much faster, but medical physicists are working on developing faster MRI machines.

CHAPEL HILL, N.C. -- It's hard enough being pregnant, but for some women, what happens during pregnancy can put their and their baby's life at risk. A simple scan at the hospital could increase the chance of developing cancer. Now, a new scan is making it safer for doctors to help pregnant women who are in pain.

Radiologist Richard Semelka is using MRI to help safely see inside a pregnant women, keeping the baby free from the risks of radiation.

"MRI uses magnetic waves and radiofrequency energy, and CT uses X-rays in order to generate the images," Dr. Semelka, of University of North Carolina Hospitals in Chapel Hill, tells DBIS.

CT scans increase cancer risks in both the baby and the mother, but now new studies show MRI is safer and just as accurate.

Dr. Semelka has diagnosed breast cancer, ovarian cysts, kidney stones, bowel problems and appendicitis with the MRI. He was able to see an enlarged appendix in one woman and remove it before it ruptured, saving her and her baby.

A CT scan takes about five minutes and MRI lasts for an hour, but doctors are working to create an faster MRI.

BACKGROUND: A new study from the University of North Carolina Hospitals in Chapel Hill shows that MRI is both safe and accurate for diagnosing pregnant women with acute pain in the abdomen and pelvis, surpassing the limits of both CT scans and ultrasound for this purpose. The researchers analyzed the MRIs of 29 pregnant patients who had been experiencing acute abdominal pain, and correctly diagnoses the cause of that pain in 28 of those cases. Some of the problems that can be diagnosed include acute appendicitis, fibroids, ovarian cysts, kidney stones, gall bladder problems, and problems with the fetus itself.

A NEW ALTERNATIVE: It can be difficult to diagnose acute abdominal pain in pregnant women because the enlarged uterus pushes organs out of their normal locations, so the pain is not in the usual place. There are also more possible causes for pain,. Today, CT scanning is normally used for diagnosing abdominal pain, but there is a risk of exposing the fetus to harmful ionizing radiation, increasing cancer risks in both fetus and mother. Ultrasound (sonography) doesn't use radiation, but its imaging potential is limiting. MRI is becoming a desirable option as the medical community and the public becomes more aware of the risks associated with radiation, particularly for pregnant women. The latest generation of MRI scanners has reduced the time needed to image a patient, so it is becoming possible to see what is actually happening inside the abdomen or pelvis.

ABOUT CAT SCANS: CAT (Computerized Axial Tomography) scans are similar to conventional X-ray imaging, but instead of imaging the outline of bones and organs, a CAT scan machine forms a full three-dimensional computer model of the inside of a patient's body. Doctors can even examine the body one narrow slice at a time. The X-ray beam moves all around the patient, scanning from hundreds of different angles, and the computer takes all that information to compile a 3D image of the body.

HOW MRI WORKS: Magnetic resonance imaging uses radiofrequency waves and a strong magnetic field instead of X-rays to provide clear and detailed pictures of internal organs and tissues. These radio waves are directed at protons in hydrogen atoms -- one of the most abundant atoms in the human body, because of the body's high water content. The waves "excite" the protons, and when they "relax," they emit strong radio signals. A computer can turn those signals into a high-contrast image showing differences in the water content and distribution in various bodily tissues. It is becoming increasingly popular as an alternative to traditional X-ray mammography for the early diagnosis of breast cancer because women aren't exposed to the same radiation they experience with X-rays.

Sciencedaily.com

Излучение рентгена сравнили со взрывом атомной бомбы

Американские рентгенологи предупреждают, что излишние процедуры компьютерной томографии могут приводить к возникновению раковых заболеваний у пациентов.

По оценкам специалистов, при проведении компьютерной томографии всего тела пациента, он получает такую же дозу облучения, какую получили люди, находившиеся в 2,4 км от эпицентров взрывов в Хиросиме и Нагасаки.

Экспертная группа Американской коллегии рентгенологов опубликовала доклад, в котором ученые обозначили существующую проблему и предложили пути ее решения, сообщает NewScientist.

Doctors warn of harmful medical screening

Doctors are warning the public that unregulated elective screening tests – such as whole body CT scans or early mammograms – could cause patients far more harm than good.

They say private sector screening tests, which can be heavily marketed and not always to the people most at risk of a disease, are becoming more popular in the UK. In 2004 alone, private tests including whole-body computerised tomography (CT) scans, ECGs (electrocardiograms), mammograms in young women and PSA tests for prostate cancer, raked in £65 million.

The medical evidence for the benefits versus harm of the privately-funded screening is “often quite sketchy”, says Charles George, chair of the British Medical Association’s board of science, which published the report on screening on Tuesday.

The report says unregulated screening is often for profit – unlike national screening programmes – and may not have good quality control. Information and support for patients may also be lacking, the document claims.

The report stresses that “screening is a whole system, not just a test”. In the UK there are several nationally run screening programmes available for free via the country’s National Health Service. These include breast cancer screening for all women aged 50 to 64, and the newly announced national bowel cancer screening programme, scheduled to start in April 2006.

“Where tests are going to be of advantage to people they are available as national screening programmes, “ asserts Vivienne Nathanson, the BMA’s head of science and ethics. “They are carefully structured to make sure they maximise benefits and minimise the harms.”

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CT scan radiation can equal nuclear bomb exposure

Overzealous doctors who order unnecessary body scans that use X-ray technology are placing their patients at risk of cancer, radiologists warn.

Radiation from such scans is in some cases equivalent to that received by some survivors of the Hiroshima and Nagasaki atomic bombs, they say. In response, hospitals and professional associations, such as the American College of Radiologists, are taking new steps to promote more careful use of scanning technologies.

Radiologists are particularly concerned about the use of computed tomography, also known as CT or CAT scans. This technology involves the use of an X-ray generating device that rotates around the patient's body. These powerful beams are picked up by an array of detectors and used by a computer to generate a three-dimensional view of a body region.

Experts agree that when used correctly, such scans can save lives. However, according to some estimates, the radiation exposure a patient receives from a full-body CT scan is often 500 times that of a conventional X-ray and about the same as that received by people living 2.4 kilometres away from the centres of the World War II atomic blasts in Japan.

A CT scan might increase a person's risk of cancer by about 0.05%, although experts stress that on average a person's lifetime risk of cancer is about 20%.

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Annual CT scans boost cancer risk

Patients undergoing a full-body computed tomography (CT) scan are exposed to a radiation dose equivalent to that received by some survivors of the Hiroshima and Nagasaki atomic bombs, say US researchers.

This exposure has been linked with a significant rise in cancer mortality and younger patients are especially at risk.

CT scanners rotate around the body taking a series of cross-sectional X-ray “slices”, which are compiled by computer to produce a 3D portrait of internal organs and structure. The radiation dose received is often 500 times that of a conventional X-ray and nearly 100 times that of a mammogram.

While those patients referred for diagnostic CT scans by medical practitioners should see benefits that far outweigh the risks, those who self-refer may be increasing their risk of cancer unduly.

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Томограммы, полученные на "Юнитоме". Качество и разрешение видны невооруженным глазом. Медицинская значимость подтверждена врачами.