Contraindications to magnetic resonance imaging

Dill, Thorsten

doi:10.1136/hrt.2007.125039

Cited by 189 publications

(137 citation statements)

References 27 publications

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“…Exclusion criteria were general contraindications for CMR. 11 Sixty-five patients were eligible for the study. Their initial indication for echocardiography was routine follow-up (nϭ40); early postoperative assessment (nϭ8); clinical suspicion of prosthetic dysfunction (nϭ14); and screening before noncardiac (nϭ2) or cardiac (nϭ1) interventions.…”

Section: Patient Populationmentioning

confidence: 99%

Feasibility of Cardiovascular Magnetic Resonance to Assess the Orifice Area of Aortic Bioprostheses

Knobelsdorff‐Brenkenhoff

Rudolph

Waßmuth

et al. 2009

Circ: Cardiovascular Imaging

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Background-Prosthetic orifice area, usually calculated by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE), provides important information regarding the hemodynamic performance of aortic bioprostheses. However, both TTE and TEE have limitations; therefore accurate and reproducible determination of the orifice area often remains a challenge. The present study aimed to investigate the feasibility of cardiovascular magnetic resonance (CMR) to assess the orifice areas of aortic bioprostheses. Methods and Results-CMR planimetry of the orifice area was performed in 65 patients (43/22 stented/stentless prostheses; mean time since implantation, 3.1Ϯ2.8 years; mean orifice area [TTE], 1.70Ϯ0.43 cm 2 ; 62 normally functioning prostheses, 2 severe stenoses, and 1 severe regurgitation) in an imaging plane perpendicular to the transprosthetic flow using steady-state free-precession cine imaging under breath-hold conditions on a 1.5-T MR system. CMR results were compared with TTE (continuity equation, nϭ65) and TEE (planimetry, nϭ31). CMR planimetry was readily feasible in 80.0%; feasible with limitation in 15.4% because of stent, flow, and sternal wire artifacts; and impossible in 4.6% because of flow artifacts. Correlations of the orifice areas by CMR with TTE (rϭ0.82) and CMR with TEE (rϭ0.92) were significant. The average difference between the methods was Ϫ0.02Ϯ0.24 cm 2 (TTE) and 0.05Ϯ0.15 cm 2 (TEE). Agreement was present for stented and stentless devices and independent of orifice size. Intraobserver and interobserver variabilities of CMR planimetry were 6.7Ϯ5.4% and 11.5Ϯ7.8%. Conclusions-The assessment of aortic bioprostheses with normal orifice areas by CMR is technically feasible and provides orifice areas with a close correlation to echocardiography and low observer dependency. (Circ Cardiovasc Imaging. 2009;2:397-404.)

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Section: Patient Populationmentioning

confidence: 99%

Feasibility of Cardiovascular Magnetic Resonance to Assess the Orifice Area of Aortic Bioprostheses

Knobelsdorff‐Brenkenhoff

Rudolph

Waßmuth

et al. 2009

Circ: Cardiovascular Imaging

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“…31 Klostrofobik hastalarda kullanılamamakta-dır. 31 İnceleme zaman almakta ve hastanın uzun süre hareketsiz kalması gerekmektedir. 25 Kalsifikasyonları görüntülemede yetersizdir.…”

Section: Manyeti̇k Rezonans Görüntülemeni̇n Dezavantajlariunclassified

Should Brackets be Removed Before Magnetic Resonance Imaging?

Camcı¹

2018

Turkiye Klinikleri J Dental Sci

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Ö ÖZ ZE ET T Manyetik rezonans görüntüleme sistemi (MRG), 20 yılı aşkın süredir tıpta ve diş hekimliğinde kullanılan, iyonize radyasyon içermeyen, noninvaziv bir görüntüleme sistemidir. MRG yumuşak doku kontrastı en yüksek görüntüleme sistemidir ve migren, epilepsi, serebral palsi, menisküs, beyin tümörleri gibi birçok hastalığın teşhisinde yaygın olarak kullanılmaktadır. Ancak; MRG çekiminde, metal varlığı görüntüde artefakta yol açmaktadır. Artefakt ise teşhisi zorlaştır-makta veya imkansızlaştırmaktadır. Artefaktın boyutu; metalin manyetik duyarlılığına (ferromanyetik, diyamanyetik, paramanyetik), şekline, boyutuna, açısına, homojenitesine, MRG cihazının manyetik alan gücüne (low-field, high-field, ultra-high field) ve görüntüleme protokolüne göre değişkenlik göstermektedir. Son yıllarda özellikle baş-boyun bölgesinden alınacak MRG öncesi sık-lıkla ortodontistlerden sabit ortodontik aygıtları çıkarması istenir; ancak "debonding" işlemi, mineye zarar verme potansiyelinin dışında vakit kaybına yol açan maliyetli bir süreçtir. Ortodontide kullanılan malzemeler çok çeşitli alaşımlardan (paslanmaz çelik, titanyum, krom-kobalt, seramik) yapılmaktadır ve her birinin manyetik duyarlılığı ve artefakta yol açma potansiyeli birbirinden farklıdır. Ayrıca; sabit ortodontik aygıtlar MRG' de görüntülenmek istenen anatomik alanın uzaklığına bağlı olarak ilgili bölgede değişen oranlarda artefakta yol açabilir ya da açmayabilir. Bu ça-lışmada; MRG nedir?, MRG'nin avantajları ve dezavantajları, manyetik alan kuvvetinin ortodontide kullanılan materyaller üzerine etkileri, Ortodontik aygıtların MRG üzerine etkileri gibi konu baş-lıkları altında MRG öncesi braketlerin çıkarılıp çıkarılmamasına karar vermede ortodontistlere yardımcı olacak bilgilerin sunulması amaçlanmıştır.A An na ah ht ta ar r K Ke el li im me el le er r: : Manyetik rezonans görüntüleme; artefaktlar (insan eliyle yapılmış); ortodontik gereçler; ortodontik braketler A AB BS ST TR RA AC CT T Magnetic resonance imaging system (MRI) is used in medicine and dentistry for more than 20 years, it does not include ionizing radiation which is a noninvasive imaging system. MRI enables highest contrast visualization of soft tissue and is widely used in the diagnosis of many diseases such as migraine, epilepsy, cerebral palsy, meniscus, brain tumors. But; the presence of metal in MRI leads to artifacts and artifact makes diagnosis difficult or impossible. The size of the artifact depends on the magnetic susceptibility of the metal (ferromagnetic, diamagnetic, paramagnetic), shape, size, angle, homogeneity, magnetic field power (low-field, highfield and ultra-high field) and imaging protocol of the MRI device. In recent years, it is often asked to remove fixed orthodontic devices from orthodontists, especially before the MRI taken from the head and neck region; but the debonding procedures is a costly process that leads to a loss of time other than the potential for damaging the enamel. Materials used in orthodontics are made from a wide variety of alloys (stainless steel, tit...

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“…However, in very specifi c circumstances in which no alternatives are available, CMR potentially can be performed safely by experienced personnel when appropriate precautions are taken [45]. Decisions to perform the study in the presence of metallic objects are based on the magnetic and electric properties of the object, location, and time of implantation [46,47]. Arrhythmias with very variable R-R intervals should be controlled before scanning.…”

Section: Limitationsmentioning

confidence: 99%

Cardiovascular magnetic resonance of cardiomyopathies

Alpendurada

O’Hanlon²,

Prasad

2008

Curr Cardiol Rep

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Cardiomyopathies are a heterogeneous group of diseases of the myocardium associated with architectural abnormalities and mechanical dysfunction. Recent advances in our understanding of the genetics, pathophysiology, and natural history of these conditions has resulted in better diagnosis and management, leading to improvements in mortality. Major developments in imaging techniques, in particular contrast-enhanced MRI, now permit in vivo tissue characterization of the myocardium. Through defining disease severity, etiology, and to some extent in risk stratification, routine cardiovascular magnetic resonance evaluation of this group of patients provides essential information required in everyday clinical practice.

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Contraindications to magnetic resonance imaging

Cited by 189 publications

References 27 publications

Feasibility of Cardiovascular Magnetic Resonance to Assess the Orifice Area of Aortic Bioprostheses

Feasibility of Cardiovascular Magnetic Resonance to Assess the Orifice Area of Aortic Bioprostheses

Should Brackets be Removed Before Magnetic Resonance Imaging?

Cardiovascular magnetic resonance of cardiomyopathies

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