American College of Radiology White Paper on MR Safety

Kanal, Emanuel; Borgstede, James P.; Barkovich, A. James; Bell, Charlotte; Bradley, William G.; Felmlee, Joel P.; Froelich, Jerry W.; Kaminski, Ellisa M.; Keeler, Elaine K.; Lester, James W.; Scoumis, Elizabeth A.; Zaremba, L; Zinninger, M.

doi:10.2214/ajr.178.6.1781335

Cited by 245 publications

(129 citation statements)

References 6 publications

Supporting

Mentioning

125

Contrasting

Unclassified

Order By: Relevance

“…The lead had a length of 62 cm for all experiments, with an active tip area of 6 mm 2 and an active ring area of 36 mm 2 . Both the rectangular box and the humanshaped phantom were filled with a gel composed of the following materials (in percent, by weight): 2% hydroxyethylcellulose (HEC; commercial name Natrosol); 97.64% water; and 0.36% sodium chloride.…”

Section: Methodsmentioning

confidence: 99%

“…MAGNETIC RESONANCE IMAGING (MRI) is now contraindicated for patients implanted with pacemakers (PMs) and implantable cardioverter-defibrillators (ICDs) (1)(2)(3)(4)(5)(6). The potential effects of MRI on PMs, ICDs, and other active implantable medical devices (AIMDs) include: force and torque effects (7,8); an undefined reedswitch state within the static magnetic field (9); the potential risk of heart stimulation and inappropriate pacing (10,11); and heating effects at the lead tip (12)(13)(14).…”

mentioning

confidence: 99%

See 1 more Smart Citation

In vitro investigation of pacemaker lead heating induced by magnetic resonance imaging: Role of implant geometry

Calcagnini¹,

Triventi²,

Censi³

et al. 2008

Magnetic Resonance Imaging

View full text Add to dashboard Cite

Purpose:To evaluate the effect of the geometry of implantable pacemakers (PMs) on lead heating induced by magnetic resonance imaging (MRI). Materials and Methods:In vitro experiments were conducted with two different setups, using fluoroptic probes to measure the temperature increase. The first experiment consisted of a rectangular box filled with a gelled saline and a pacemaker with its leads. This box was exposed in an MRI birdcage coil to a sinusoidal 64-MHz field with a calibrated whole-body specific absorption rate (WB-SAR) of 1 W/kg. The highest SAR and temperature increase (3000 W/kg, 12°C) occurred for the implant configuration having the largest area. The second experimental setup consisted of a human-shaped torso filled with gelled saline. In this setup the PM and its lead were exposed to a real MRI scanner, using clinical sequences with WB-SAR up to 2 W/kg. Results:We found that higher heating occurs for configurations with longer exposed lead lengths and that right chest PMs showed the highest temperature and local SAR (11.9°C, 2345 W/kg), whereas the left chest PMs were less heated (6.3°C, 1362 W/kg). Implant geometry, exposed lead length, and lead area must be considered in the wide variation of temperature increases induced by MRI. Conclusions:The amount of MRI-induced lead tip heating depends strongly on implant geometry, particularly the lead area, exposed lead length, and position of the implant in the phantom. Critical lead tip heating was found for the longer leads. Therefore, to minimize MRI-induced lead tip heating, the PM lead should be as short as possible.

show abstract

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

In vitro investigation of pacemaker lead heating induced by magnetic resonance imaging: Role of implant geometry

Calcagnini¹,

Triventi²,

Censi³

et al. 2008

Magnetic Resonance Imaging

View full text Add to dashboard Cite

show abstract

“…The American College of Radiology white paper on MR safety published in 2002 states that ''Pregnant patients can be accepted to undergo MR images at any stage of pregnancy if, in the determination of a Level Two MR Personnel-designated attending radiologist, the riskbenefit ratio to the patient warrants that the study be performed.'' [13] However, because of the potential risk of MRI to the developing fetus and the current limitations of fetal MRI, it is prudent to wait until after the first trimester before performing fetal MRI. In fact, it is preferable to wait until at least gestational week 22 to minimize the difficulties created by the small size and excessive motion of younger fetuses.…”

Section: Discussionmentioning

confidence: 99%

Lumbosacral lordosis in fetal spine: genetic or mechanic parameter

et al. 2009

View full text Add to dashboard Cite

Many believe that the fetus spine had only one curvature from cranial to caudal which is a global kyphosis and that the lumbosacral lordosis appears with the erect posture. They agree that the sacrum of Homo sapiens is not positioned posteriorly at birth and that it is during the first few years that the sacrum, in humans, moves dorsally in relation with the progressive acquisition of erect posture and the ontogeny of bipedal locomotion. Nevertheless, there is no biometric study assessing these parameters in vivo in utero during the fetal life. Cross-sectional biometric study of the lumbosacral junction of the spine in in utero fetuses was to document the presence of a lumbosacral lordosis in the fetal population in utero long before standing and walking and its change during growth. Fortyfive MRIs (magnetic resonance imaging) of fetuses aged of 23-40 weeks of gestation were analyzed. The measurements were performed on computerized MRI DICOM images using a professional software to calculate the curvature and radius of the lumbosacral junction. The presence or absence of visual lumbosacral lordosis was noted for each case. Correlation tests were performed in order to disclose a correlation between the gestational age and the curvature calculated. A test was considered significant for P \ 0.01. There were 14 males, 17 females and 14 undetermined. All the curves (100%) showed mathematically the presence of a lordosis in the lumbosacral region. The visual lumbosacral lordosis was present in 60% of cases. The measurement of the lumbosacral curvature varies between -0.133 and -0.033 mm -1 and a mean of -0.054 mm -1 with a corresponding radius ranging from -7 to -303 mm with a mean of -18.7 mm. The statistical analysis showed no correlation between the gestational age and the lumbosacral curvature (R 2 = 0.11). The hypothesis of increased lumbosacral lordosis with gestational age is rejected. It is difficult to accurately determine the role played separately by genetics and by erect posture. A visual lumbosacral lordosis was noted in 60% of cases with mean radius of -18.6691 mm. This lordosis was not correlated statistically to gestational age which means that it is not related to growth and might be genetically determined. Mechanical factors may play a major role in the determination of the shape of the growing pelvis. One can ask if the pelvis morphology is genetically determined or if it is mechanically determined under muscular and ligamentous stresses. This study shows that the sacrum of human fetuses is oriented posteriorly mathematically in 100% of cases, and in 60% of cases based on the morphologic appearance of the lumbosacral junction. So beside the effect of progressive acquisition of erect posture and bipedalism in determining the formation of lumbosacral angle, we believe that genetics play an important role in the formation of the lumbosacral angle.

show abstract

“…It is equally important to acknowledge the limitations of MRI in terms of both diagnostic accuracy and safety. Patients with cardiac pacemakers and ferrous intracranial vascular clips are not candidates for MRI (68), and indeed MRI has been reported to cause death in such patients (69). The known hazards associated with flying ferromagnetic objects, internal prostheses, and wire or metal objects in contact with the skin of patients can be avoided by the routine implementation of mandatory screening questionnaires filled out by patients before each MRI examination.…”

Section: Consider Alternatives To Ctmentioning

confidence: 99%

Imaging strategies to reduce the risk of radiation in CT studies, including selective substitution with MRI

Semelka

Armao

Elias

et al. 2007

Magnetic Resonance Imaging

198

106

View full text Add to dashboard Cite

“When one admits that nothing is certain one must, I think, also admit that some things are much more nearly certain than others.” Bertrand Russell (1872–1970) Computed tomography (CT) is one of the largest contributors to man‐made radiation doses in medical populations. CT currently accounts for over 60 million examinations in the United States, and its use continues to grow rapidly. The principal concern regarding radiation exposure is that the subject may develop malignancies. For this systematic review we searched journal publications in MEDLINE (1966–2006) using the terms “CT,” “ionizing radiation,” “cancer risks,” “MRI,” and “patient safety.” We also searched major reports issued from governmental U.S. and world health‐related agencies. Many studies have shown that organ doses associated with routine diagnostic CT scans are similar to the low‐dose range of radiation received by atomic‐bomb survivors. The FDA estimates that a CT examination with an effective dose of 10 mSv may be associated with an increased chance of developing fatal cancer for approximately one patient in 2000, whereas the BEIR VII lifetime risk model predicts that with the same low‐dose radiation, approximately one individual in 1000 will develop cancer. There are uncertainties in the current radiation risk estimates, especially at the lower dose levels encountered in CT. To address what should be done to ensure patient safety, in this review we discuss the “as low as reasonably achievable” (ALARA) principle, and the use of MRI as an alternative to CT. J. Magn. Reson. Imaging 2007;25:900–909. © 2007 Wiley‐Liss, Inc.

show abstract

American College of Radiology White Paper on MR Safety

Cited by 245 publications

References 6 publications

In vitro investigation of pacemaker lead heating induced by magnetic resonance imaging: Role of implant geometry

In vitro investigation of pacemaker lead heating induced by magnetic resonance imaging: Role of implant geometry

Lumbosacral lordosis in fetal spine: genetic or mechanic parameter

Imaging strategies to reduce the risk of radiation in CT studies, including selective substitution with MRI

Contact Info

Product

Resources

About