Atrial septal defect MRI: Difference between revisions
Jump to navigation
Jump to search
| Line 35: | Line 35: | ||
==Supportive trial data== | ==Supportive trial data== | ||
In a study done by Hundley et al. velocity-encoded, phase difference MRI have been found to assess the magnitude of left-to-right shunting as reliably as was done by cardiac catheterization. Also, it has the additional advantage of being a non-invasive tool compared to the invasive cardiac catheterization.<ref name="pmid7796506">{{cite journal| author=Hundley WG, Li HF, Lange RA, Pfeifer DP, Meshack BM, Willard JE et al.| title=Assessment of left-to-right intracardiac shunting by velocity-encoded, phase-difference magnetic resonance imaging. A comparison with oximetric and indicator dilution techniques. | journal=Circulation | year= 1995 | volume= 91 | issue= 12 | pages= 2955-60 | pmid=7796506 | doi= | pmc= | url= }} </ref> | * In a study done by Hundley et al. velocity-encoded, phase difference MRI have been found to assess the magnitude of left-to-right shunting as reliably as was done by cardiac catheterization. Also, it has the additional advantage of being a non-invasive tool compared to the invasive cardiac catheterization.<ref name="pmid7796506">{{cite journal| author=Hundley WG, Li HF, Lange RA, Pfeifer DP, Meshack BM, Willard JE et al.| title=Assessment of left-to-right intracardiac shunting by velocity-encoded, phase-difference magnetic resonance imaging. A comparison with oximetric and indicator dilution techniques. | journal=Circulation | year= 1995 | volume= 91 | issue= 12 | pages= 2955-60 | pmid=7796506 | doi= | pmc= | url= }} </ref> | ||
In another study done by Holmvang et al. Phase-contrast cine MRI has been found to be more reliable than Spin-echo images. The phase contrast MRI defines the defect shape by the cross section of the shunt flow. Due to the accurate diagnosis of the defect size it helps in making a decision on the therapeutics aspect of the patient i.e. transcutaneous catheter or surgical closure. On the other hand, spin-echo images, are not very accurate in finding ASD size and septal thinning adjacent to a secundum ASD may be falsely considered a part of the defect | * In another study done by Holmvang et al. Phase-contrast cine MRI has been found to be more reliable than Spin-echo images. The phase contrast MRI defines the defect shape by the cross section of the shunt flow. Due to the accurate diagnosis of the defect size it helps in making a decision on the therapeutics aspect of the patient i.e. transcutaneous catheter or surgical closure. On the other hand, spin-echo images, are not very accurate in finding ASD size and septal thinning adjacent to a secundum ASD may be falsely considered a part of the defect | ||
==References== | ==References== | ||
Revision as of 17:24, 30 August 2011
|
Atrial Septal Defect Microchapters | |
|
Treatment | |
|---|---|
|
Surgery | |
|
| |
|
Special Scenarios | |
|
Case Studies | |
|
Atrial septal defect MRI On the Web | |
|
American Roentgen Ray Society Images of Atrial septal defect MRI | |
|
Risk calculators and risk factors for Atrial septal defect MRI | |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [[2]]; Cafer Zorkun, M.D., Ph.D. [3]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S. [[4]]
Overview
Magneic resonance imaging (MRI) is a noninvasive imaging modality that can be used as a diagnostic tool in identifying an atrial septal defect. MRI aids in direct visualization of the atrial septal defect and pulmonary veins. It can assist in quantifying ventricular volume and function as well as shunt size. Velocity-encoded, phase difference MRI have been found to assess the magnitude of left-to-right shunting as reliably as is done by cardiac catheterization [1]. Also it has the additional advantage of being a non-invasive tool compared to the invasive cardiac catheterization.
Magnest Resonance Imaging (MRI)
- Non-invasive imaging method
- Effective tool for when echocardiographic results are inconclusive.
- Provides better visualization of heart vasculture
Indications
- Effective in measuring:
- Flow measurements from the aorta and main pulmonary vein
- Shunt flow
- Heart volumes
- Blood flows
- Ventricular wall thickness
- Size of the septum defect
- Provides identification of additional associated anomalies
Advantages
- Phase velocity mapping helps in measuring the ratio of pulmonary to systemic blood flow (Qp:Qs).
- Quantifies ventricular volume and function and shunt size
- Provides an assessment of the pressure gradient across the valves and atria
- Can provide morphologic image of the heart in neonates
- Provides multiple images of the heart per cardiac cycle
Disadvantages
- Certain physiologic formations can be misidentified, such as a thin fossa ovalis, and mistaken for an ostium secundum defect.
- Imaging, specifically static images, can provide a skewed perception of the thickness of the septum.
- Lacks large study backing, needs more clinical trial investigation to further evaluate the potential indications and limitations of the technique.
- In pediatrics, it may require general anesthesia. This may be less desirable as echocardiography does not.
Supportive trial data
- In a study done by Hundley et al. velocity-encoded, phase difference MRI have been found to assess the magnitude of left-to-right shunting as reliably as was done by cardiac catheterization. Also, it has the additional advantage of being a non-invasive tool compared to the invasive cardiac catheterization.[1]
- In another study done by Holmvang et al. Phase-contrast cine MRI has been found to be more reliable than Spin-echo images. The phase contrast MRI defines the defect shape by the cross section of the shunt flow. Due to the accurate diagnosis of the defect size it helps in making a decision on the therapeutics aspect of the patient i.e. transcutaneous catheter or surgical closure. On the other hand, spin-echo images, are not very accurate in finding ASD size and septal thinning adjacent to a secundum ASD may be falsely considered a part of the defect
References
- ↑ 1.0 1.1 Hundley WG, Li HF, Lange RA, Pfeifer DP, Meshack BM, Willard JE; et al. (1995). "Assessment of left-to-right intracardiac shunting by velocity-encoded, phase-difference magnetic resonance imaging. A comparison with oximetric and indicator dilution techniques". Circulation. 91 (12): 2955–60. PMID 7796506.