Magnetic Resonance Imaging

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Contents

More Specific Terms

Introduction

Indications

  • clinical indications for MRI
  • structural diseases of the brain (MRI is the imaging modality of choice)
  • * gadolinium is the enhancing agent commonly used for MRI superparamagnetic iron oxides is another enhancing agent [6]

Advantages

  • high sensitivity
  • sectional images in multiple planes
  • * advantages of MRI over CT

Contraindications

  • metal (any ferromagnetic material)
  • Star-Edwards valve (caged ball valve)
  • serious adverse events, including patient death due to dosing inaccuracies & other mechanical pump problems
  • only implantable infusion pumps labeled as MR Conditional may be safely used as specified by the manufacturer [11]

Disadvantages

  • small bore & long hollow tube of the magnet excludes:
  • patients with pacemakers
  • patients with ferromagnetic appliances
  • * limitations of MRI

Procedure

  • patient is advanced into bore of magnet in supine position on floating table
  • ear-plugs or ear- music systems are commonly used because of high noise level
  • entire exam takes 20-45 minutes
  • multiple imaging sequences in multiple planes b)imaging sequences range from 1 second to 10 minutes

Notes

More General Terms

Additional Terms

References

  1. Introduction to Clinical Imaging, Radiology Syllabus, UCSF, 1993
  2. Medical Knowledge Self Assessment Program (MKSAP) 11,16,17. American College of Physicians, Philadelphia 1998,2012,2015.
  3. Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 2289
  4. Veterans Affairs (VA) National Center for Patient Safety Magnetic Resonance Imaging (MR) Hazard Summary [1]
  5. UpToDate 14.1 [2]
  6. Aguirre DA, Behling CA, Alpert E, Hassanein TI, Sirlin CB. Liver fibrosis: noninvasive diagnosis with double contrast material-enhanced MR imaging. Radiology. 2006 May;239(2):425-37. PMID: [3]
  7. Sommer T et al, Strategy for safe performance of extrathoracix magnetic resonance imaging at 1.5 tesla in the presence of cardiac pacemakers in non-pacemaker-dependent patients: A prospective study with 115 examinations. Circulation 2006, 114:1285 PMID: [4]
    - Nazarian S et al, Clinical utility and safety of a protocol for non-cardiac magnetic resonance imaging of patients with permanent pacemakers and implantable-cardioverter defibrillators at 1.5 tesla. Circulation 2006, 114:1277 PMID: [5]
  8. Nazarian S et al. A prospective evaluation of a protocol for magnetic resonance imaging of patients with implanted cardiac devices. Ann Intern Med 2011 Oct 4; 155:415 PMID: [6]
    - Reynolds MR and Zimetbaum P. Magnetic resonance imaging and cardiac devices: How safe is safe enough? Ann Intern Med 2011 Oct 4; 155:470. PMID: [7]
  9. Kim BG et al Adverse Events and Discomfort During Magnetic Resonance Imaging in Cochlear Implant Recipients. JAMA Otolaryngol Head Neck Surg. November 20, 2014 <PubMed> PMID: [8] <Internet> [9]
    - Kanal E Magnetic Resonance Imaging in Cochlear Implant Recipients. Pros and Cons. JAMA Otolaryngol Head Neck Surg. November 20, 2014 <PubMed> PMID: [10] <Internet> [11]
  10. Ray JG, Vermeulen MJ, Bharatha A et al Association Between MRI Exposure During Pregnancy and Fetal and Childhood Outcomes. JAMA. 2016;316(9):952-961 <PubMed> PMID: [12] <Internet> [13]
  11. FDA Safety Communication. Jan 11, 2017 Safety Concerns with Implantable Infusion Pumps in the Magnetic Resonance (MR) Environment. [14]
  12. Russo RJ, Costa HS, Silva PD et al Assessing the Risks Associated with MRI in Patients with a Pacemaker or Defibrillator. N Engl J Med 2017; 376:755-764. February 23, 2017 <PubMed> PMID: [15] <Internet> [16]
  13. FDA News Release. July 20, 2017 FDA clears first neonatal magnetic resonance imaging device. [17]
  14. FDA News Release. Oct 12, 2017 FDA clears first 7T magnetic resonance imaging device. [18]
  15. National Guideline Clearinghouse
    - Practice advisory on anesthetic care for magnetic resonance imaging: an updated report by the American Society of Anesthesiologists Task Force on Anesthetic Care for Magnetic Resonance Imaging. ngc-guideline: [19]
    - The use of magnetic resonance imaging in the obstetric patient. Society of Obstetricians and Gynaecologists of Canada ngc-guideline: [20]

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