近年，心臓MRIは技術的革新が急速に進み，撮影技術や装置の進歩に伴って，さまざまな臨床応用方法が編み出され，無限の広がりを見せている．そのうちのいくつかは，十分な実測値の裏付けを基に，すでに日常臨床に汎用されている．これらの進歩と経験の蓄積により，CMRは，局所壁運動や心室収縮能，先天性心疾患の血行動態，心筋梗塞の検出やviability確認，心外膜疾患や心臓腫瘍評価の標準的検査となった．小児循環器医がCMRを十二分に活用するためにまず把握しておく点は以下6点である．
1）被曝がなく低侵襲
2）心エコーと異なり見えない場所がない（Window制限がない）→正確な容積・心室機能評価が可能．
3）あらゆる血管の血流量が計測できる
4）非造影で3D形態把握が可能
5）心筋性状がわかる
6）欠点は，低機動性，磁性体，労力（熟練を要する）．
ここではCMRの技術的側面・運用方法と小児患者に用いる際に考慮すべき要点について解説する．
Cardiac magnetic resonance imaging (CMR) has undergone rapid evolution over the last few years. Significant advances in pulse sequence design, scanner hardware, and coil technology have resulted in progressive expansion of the clinical applications of CMR. Some of these have already been applied in daily clinical use, based on in vitro and in vivo validation. CMR is now recognized as the reference standard for the assessment of regional and global systolic function, hemodynamics of congenital heart disease, detection of myocardial infarction and viability, and the evaluation of pericardial disease and cardiac masses. When using CMR, pediatric cardiologists must understand six key features:
1) The non-invasive modality without exposure to harmful ionizing radiation.
2) Precise volumetric and functional analysis without restrictions related to acoustic windows, scar tissue, and other postoperative changes.
3) Ability to measure flow volume for almost all blood vessels.
4) Ability to display cardiovascular anatomy in three-dimensional projections without contrast medium.
5) Ability to assess myocardial tissue characterization.
6) Disadvantages including lack of portability, implanted magnetic material, and time and labor consuming (with high skill requirements).
In this review we described the key technical and practical aspects of CMR and highlighted some important considerations for pediatric patients.
