Cochlear Implants & MRI Safety

This is a guest article from MED-EL, the innovation leader in hearing implants.

You don’t want to have to turn a patient away from an MRI scan. But active medical implants, such as pacemakers or cochlear implants, can make MRI scans challenging.

Many implants are associated with risks during MRI, even if they are “MR Conditional”. This can be especially challenging in real-world settings, because “MR Conditional” only means that there are conditions and restrictions, without letting you know how to proceed or how likely it is that your patient will have a safe, comfortable MRI scan.

However, it’s important to understand that not all implants are created equal—especially when it comes to MRI safety.

Today, we’re going to take an in-depth look at why a design issue causes complications with certain cochlear implants. Then we’ll look at why magnet technology makes all the difference with a whole range of hearing implants designed specifically for MRI safety.

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24
Apr 2019
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Interview: Prof. Boris Brkljačić, professor of radiology and Vice-Dean at the University of Zagreb School of Medicine, Croatia

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This year, the main theme of the International Day of Radiology is breast imaging. To get some insight into the field, we spoke to Prof. Boris Brkljačić, professor of radiology and Vice-Dean at the University of Zagreb School of Medicine, Croatia, and Chairman of the ESR Communications and External Affairs Committee.

European Society of Radiology: Breast imaging is widely known for its role in the detection of breast cancer. Could you please briefly outline the advantages and disadvantages of the various modalities used in this regard?
Boris Brkljačić: Mammography, ultrasound and MRI are three modalities used for the detection of breast cancer. Mammography has been used for many decades, and the introduction of full flat panel digital mammography has enabled image acquisition with a lower radiation dose, and other advantages in image processing and biopsies. Mammography is used widely in breast cancer screening and has been validated through decades of screening. It is also the initial imaging method in women older than 40 and it enables the detection of microcalcifications, the early signs of ductal cancer in situ, and the majority of breast cancers, depending on the radiographic density of the breast. It can also be used to guide biopsy of microcalcifications. The denser the breasts are, the lower the sensitivity of mammography in detecting breast lesions, which is the disadvantage of mammography. The new mammographic method, digital tomosynthesis, improves the detection rate of cancer in dense breasts. Mammography exposes patients to radiation and is therefore not recommended in young women because their breasts are very radiosensitive.

Prof. Boris Brkljačić, Professor of Radiology and Vice-Dean at the University of Zagreb School of Medicine, Croatia, and Chairman of the ESR Communications and External Affairs Committee.

Prof. Boris Brkljačić, Professor of Radiology and Vice-Dean at the University of Zagreb School of Medicine, Croatia, and Chairman of the ESR Communications and External Affairs Committee.

Ultrasound is an imaging method that provides images based on the acoustic properties of tissues. The blood flow in lesions can be analysed by colour Doppler ultrasound, and elasticity of lesions can be analysed and quantified by sonoelastography. The advantage of ultrasound is that it is completely harmless; it does not expose patients to radiation, and is an excellent method for the guidance of biopsies of all sonographically visible lesions. Ultrasound can demonstrate cancers that are not visible in mammographically dense breasts, and is the complementary imaging modality to mammography, both in diagnosis and in screening. Some U.S. states legally oblige physicians to inform women about mammographic density and advise them of additional methods of examination in dense breasts. Among many advantages in ultrasound technology are the automated whole-breast ultrasound systems that have recently been introduced to the market. The disadvantage of ultrasound is that it increases the number of false-positive findings.

Magnetic resonance imaging (MRI) of the breast has gained considerable importance over the last two decades and is used more and more in breast imaging. It is used in high-risk screening, in the detection of occult cancer with positive lymph nodes, and in the evaluation of implants, and it is the best method for detecting the presence of and assessing the distribution and extent of cancer. It can also be used to monitor the success of neoadjuvant chemotherapy, and is an excellent method for looking for residual cancer or recurrence after treatment. MRI is relatively expensive and time consuming, although abbreviated MRI protocols have recently been introduced.

For treatment planning and monitoring it is very important to know the exact type and grade of cancer, and its immunohistochemical profile. Image guided biopsy is crucial in relation to that, and all imaging methods enable precise, image-guided biopsy to obtain an adequate sample from the breast cancer and other breast lesions.
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Interview: Dr. Ilse Vejborg, head of radiology at the University Hospital of Copenhagen, Rigshospitalet, Denmark.

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This year, the main theme of the International Day of Radiology is breast imaging. To get some insight into the field, we spoke to Dr. Ilse Vejborg, head of radiology at the University Hospital of Copenhagen, Rigshospitalet and head of the Capital Mammography Screening programme in Denmark.

European Society of Radiology: Breast imaging is widely known for its role in the detection of breast cancer. Could you please briefly outline the advantages and disadvantages of the various modalities used in this regard?
Ilse Vejborg: Mammography is a fast examination, showing the whole breast, if performed properly. Mammography has a high sensitivity to fatty tissue but the sensitivity can be compromised in dense breasts. Ultrasonography is an important supplementary examination which should be used in diagnostic examinations of women with palpable lumps or other symptoms in the breast. In experienced hands, ultrasound is the best examination for distinguishing a solid from cystic palpable lump but often also for evaluating whether the lump looks benign or malignant. Ultrasonography offers the possibility of evaluating the blood flow (Doppler) and stiffness (elastography) in a process and can be used to perform ultrasound-guided interventions.

MR Mammography has the highest sensitivity of all the imaging modalities but a more varying specificity; the latter is probably partly explained by the fact that in contrast to mammography screening, where high volume readers reading more than 5,000 examinations a year are mandatory, high volume readers of MR mammography are rarer.

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Dr. Ilse Vejborg, head of radiology at the University Hospital of Copenhagen, Rigshospitalet and head of the Capital Mammography Screening programme in Denmark.

ESR: Early detection of breast cancer is the most important issue for reducing mortality, which is one reason for large-scale screening programmes. What kind of programmes are in place in your country and where do you see the advantages and possible disadvantages?
IV: In Denmark we have nationwide, organised, population-based mammography screening. Mammography screening is offered every second year free of charge in the target age group of women aged 50–69 years. Mammography screening is the only imaging modality proven to reduce breast cancer mortality. It is a fast and inexpensive examination which can be performed without the presence of the physicians. In Denmark, all screening centres have digital mammography equipment and RIS and PACS systems.

Nationwide mammography screening in Denmark was implemented rather late compared to our Nordic neighbours and Denmark has had a higher mortality of breast cancer than the other Nordic countries. Mammography screening started in Copenhagen municipality in 1991, in the county of Fyn in 1993 and in the municipality of Frederiksberg (close to Copenhagen) in 1994. These programmes offering screening only to around 20% of the target population were for many years the only screening programmes in Denmark. Not until 2010 did we have a nationwide roll out of mammography screening.

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Interview: Dr. Viera Lehotská, head of radiology at Comenius University and St. Elizabeth’s Cancer Institute, Bratislava, Slovakia.

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This year, the main theme of the International Day of Radiology is breast imaging. To get some insight into the field, we spoke to Dr. Viera Lehotská, Associate Professor and Head of the 2nd Radiology Department of the Faculty of Medicine Comenius University and St. Elizabeth’s Cancer Institute, Bratislava, Slovakia.

European Society of Radiology: Breast imaging is widely known for its role in the detection of breast cancer. Could you please briefly outline the advantages and disadvantages of the various modalities used in this regard?
Viera Lehotská: Mammography, including recent trends (e.g. tomosynthesis), is considered to be an essential, highly sensitive and representative method in the diagnostics of non-palpable breast lesions, especially those with the presence of microcalcifications. Based on this fact, mammography is generally accepted as the only proper method for active detection of breast cancer in the screening process. One disadvantage is the use of ionising radiation, and some patients might also consider the need for breast compression during imaging another disadvantage. But its contribution to the diagnosis of early stages of breast cancer significantly outweighs these limitations.

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Dr. Viera Lehotská, Associate Professor and Head of the 2nd Radiology Department of the Faculty of Medicine Comenius University and St. Elizabeth’s Cancer Institute, Bratislava, Slovakia.

Ultrasound examination of the breast and the axilla serves as the main complementary method to mammography: for differentiation between cystic and solid lesions as well as for the elimination of occult lesions in dense breast glands. For younger women (under 40), pregnant women, or women during lactation, as well as for women with inflammatory breast disease or impaired mammary implants, ultrasound is used as the first choice examination method. Its benefit is not only its low cost but also its repeatability and non-risk character. Together with newer trends such as US-elastography and contrast-enhanced ultrasound (CEUS), it contributes to the assessment of lesions dignity (whether it is benign or malignant). It is very helpful in the follow-up of operated and irradiated breast and is therefore an important part of the monitoring of patients after surgery for breast cancer.

MR-mammography has strictly defined indications, which, if they are kept to, makes it a robust method. It has high sensitivity in the diagnosis of invasive breast carcinoma. Its specificity can be increased by using functional MRI methods such as diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI, and MR-spectroscopy. In addition, its potential is not only in the assessment of the extent of breast cancer (multiplicity, etc.) or in the assessment of early response to neoadjuvant chemotherapy, but also in its high sensitivity in high risk groups.

Interventional methods also play a very important role, whether under the MG-stereotactic, ultrasound or MR-navigation. Preoperative histologisation of breast lesions by standard vacuum-assisted biopsy or by the Intact BLES (Breast Lesion Excision System) is an indispensable part of the exact diagnosis of the character of breast lesions. Similarly, image-guided localisation techniques enable effective surgical treatment of breast cancer.

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Interview: Dr. Sophie Dellas, head of breast imaging and diagnostics at the University Hospital Basel, Switzerland

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This year, the main theme of the International Day of Radiology is breast imaging. To get some insight into the field, we spoke to Dr. Sophie Dellas, assistant professor of radiology and division head of breast imaging and diagnostics at the University Hospital Basel, Switzerland, and a core team member of the certified breast centre at the same institution.

European Society of Radiology: Breast imaging is widely known for its role in the detection of breast cancer. Could you please briefly outline the advantages and disadvantages of the various modalities used in this regard?
Sophie Dellas: Mammography is the imaging modality of choice for breast cancer screening, but also for diagnosis, evaluation, and follow-up of people who have had breast cancer. Long-term results of randomised controlled trials of mammography screening on average show a decrease in breast cancer mortality of 22% in women aged 50 to 74 years. The main problem of mammography is that it is not a perfect method. Mammography generates 2D images based on the density of tissue for penetrating x-rays. The compression of the breast that is required during a mammogram can be uncomfortable. The compression is necessary to reduce overlapping of the breast tissue. A breast cancer can be hidden in the overlapping tissue and not visible on the mammogram. This is called a false negative mammogram. Mammography is associated with a false negative rate in the order of 10% to 20%. On the other hand, mammography can identify an abnormality that looks like a cancer, but turns out to be normal. This is called a false positive mammogram. Besides worrying about being diagnosed with breast cancer, a false positive means more tests and follow-up examinations. Furthermore, at least some of the cancers found with screening mammography would never otherwise be diagnosed in a patient’s lifetime. The magnitude of such overdiagnosis is a topic of much debate. It is likely to represent up to 10% of breast cancers found on screening mammography and results in potentially unnecessary treatments.

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Dr. Sophie Dellas, assistant professor of radiology and division head of breast imaging and diagnostics at the University Hospital Basel, Switzerland.

Breast ultrasound is complementary to both mammography and magnetic resonance imaging (MRI) of the breast. It does not use radiation. It is therefore the initial diagnostic method of choice if breast imaging is required below the age of 40. It allows the confident characterisation of not only benign cysts but also benign and malignant solid masses and the characterisation of palpable abnormalities. The high spatial and contrast resolution of modern breast ultrasound equipment allows the detection of subtle lesions at the size of terminal duct lobular units such as DCIS and small invasive cancers. In women with dense breasts and a negative mammogram, ultrasound therefore is increasingly used as a supplemental screening tool. The major disadvantage of ultrasound as a screening tool is the high risk of false positive findings resulting in unnecessary biopsies. The rate of false positives is much higher with screening ultrasound than with mammography or screening MRI.

Unlike mammography, MRI of the breast does not use radiation. It is safe even though it does require an intravenous injection of a contrast medium. It has a sensitivity exceeding 90% for detecting breast cancer and is superior to mammography and ultrasound. Annual MRI screening is recommended for women with a high lifetime risk of getting breast cancer. Although breast MR imaging is extremely sensitive, its specificity is limited, leading to additional workups and benign biopsies. Good quality breast MR imaging is expensive, time-consuming, and not universally available. Patients with pacemakers, certain aneurysm clips or other metallic hardware, an allergy to contrast agents, or severe claustrophobia are unable to undergo MR imaging.

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Reducing kids’ MRI anxiety, brick by brick

guest post by Benjamin Taragin

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I have always been fascinated by LEGO®. There is something soothing about raking the pile with your hands, trying to find the perfect piece to complete your next build. It was with this mindset that I was helping my son, Yoni, build one of his projects (clearly there is no pleasure in this for me ;)). As we were working with the LEGO pieces, I came across a curved semicircular piece and realised that it reminded me of the bore opening of an MRI. With that thought in my head, my son and I began to build our initial LEGO MRI model. After building it, I realised that this might actually be useful for our child life division at the Children’s Hospital at Montefiore, spearheaded by Susan Frank and Meghan Kelly, to use when prepping patients for MRI. While many simulators exist on the market, some large and some small, none are built with the basic blocks of childhood. Additionally, its small size and portability allows it to be carried around the hospital in a regular work bag.

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MRI manufacturers demonstrate the latest innovations, upgrades and enhancements

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by John Bonner

MRI has opened up the human body for radiologists to explore with remarkable precision and to gather clinical information of enduring value for physician colleagues, but the liver has so far proved a real diagnostic challenge. A combination of the organ’s complex vasculature and motion effects in free-breathing patients have meant that other modalities have often been chosen instead of MRI, particularly when looking for metastases in oncology cases.

This situation is changing due to the efforts of imaging vendors who have been working on expanding the role of this technology in body imaging. Visitors to the commercial exhibition can inspect a new software application which improves temporal resolution in MR images along with other developments that make scans both safer and more comfortable for patients.

SIEMENS is unveiling a technology that it says will make contrast-enhanced liver imaging fast and robust and allow free-breathing dynamic liver imaging, giving more patients access to high quality MR-based abdominal imaging.

Siemens’ Twist-Vibe MR sequence is designed to enable correct contrast imaging in dynamic liver MRI, allowing fast, robust liver imaging with full 4-D coverage. This series of images shows how the new technology can boost lesion enhancement within the arterial phase: with Twist-Vibe, it is now possible to generate multiple stacks of images from the arterial phase to follow the lesion enhancement over time. (Provided by University Hospital IKRN, Mannheim, Germany)

Siemens’ Twist-Vibe MR sequence is designed to enable correct contrast imaging in dynamic liver MRI, allowing fast, robust liver imaging with full 4-D coverage. This series of images shows how the new technology can boost lesion enhancement within the arterial phase: with Twist-Vibe, it is now possible to generate multiple stacks of images from the arterial phase to follow the lesion enhancement over time. (Provided by University Hospital IKRN, Mannheim, Germany)

Dr. Bernd Ohnesorge, chief executive of Siemens’ MR business unit, explained that the key software technologies underlying the company’s new Twist-Vibe and StarVibe features will be available together as a package called FREEZEit. The former is a sequence that offers high temporal and spatial resolution with full 4D coverage for multi-arterial imaging with 100% precise contrast-timing. Meanwhile, StarVibe is an application that delivers robust, free-breathing, and contrast-enhanced exams for non-compliant patients by resisting motion artefacts.

“These are acceleration techniques that allow us to do body and liver imaging at such high speed that it creates a genuine breakthrough in temporal resolution. So even in an organ as notoriously difficult to image as the liver, we can eliminate motion artefacts while also substantially enhancing contrast timing. Together that makes for a very accurate diagnosis,” he said.

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12
Mar 2014
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MRI reveals the human connectome

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Watch this session on ECR Live: Friday, March 7, 16:00–17:30, room BRB
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Radiologists often say that the brain is the next frontier. But as diffusion MRI techniques progress, the most mysterious organ in the human body starts to unveil more and more of its secrets, and what was once inconceivable a decade ago is now almost at hand.

White matter fibre pathways of the brain as depicted with MR tractography. (Provided by Patric Hagmann, CHUV-UNIL, Lausanne, Switzerland)

White matter fibre pathways of the brain as depicted with MR
tractography.
(Provided by Patric Hagmann, CHUV-UNIL, Lausanne, Switzerland)

Researchers are now better able to understand how neurons connect with one another and how disease affects these connections in the human brain. The production and later study of maps of neural connections obtained with MRI are vital to this task. A dedicated New Horizons session will cover this fascinating topic today at the ECR.

Patric Hagmann, who will chair the session, is an attending physician and neuroradiologist at Lausanne University Hospital (CHUV, Centre hospitalier universitaire vaudois) in Switzerland. In his introduction, he will describe what he calls the connectome, a term he coined in his thesis on diffusion MRI and brain connectomics back in 2005*.

“We could sum up the connectome as a comprehensive map of neural connections in the brain. The production and study of connectomes is what we refer to as connectomics; it may range from a detailed map of neurons and synapses within part of, or all of, the nervous system to a description of the functional and structural connectivity between all cortical areas and subcortical structures,” he said.

In his presentation, Hagmann will not only introduce important concepts related to connectomics like scaling, the relation between structural and functional connectivity, and the integration-segregation, but also show how advances in MRI facilitate the mapping of the human connectome.

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07
Mar 2014
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Dr. Pepe’s Diploma Casebook: Case 34 – SOLVED!

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Dear Friends,

Presenting MRI of lumbar spine in a 57-year-old male with lower-back pain.

Diagnosis:

1. Ependymoma
2. Meningioma
3. Paraganglioma
4. None of the above

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Dr. Pepe’s Diploma Casebook: Case 26 – SOLVED

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Dear Friends,

Today I’m showing a case of a 63-year-old man with left heart dysfunction and angor.

one

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