Magnetic Resonance Imaging of the Thorax: The Advantages of Coronal and Sagittal Planes Pictorial Essay

In the past 8 years, there has been steady improvement in the quality of images produced by in vivo nuclear magnetic resonance [i -3]. Despite the large volume of literature, relatively little attention has been given to magnetic resonance imaging (MRI) of the thorax. A previous report indicates that MRI of the thorax may be easily performed, requires minimal patient cooperation, and provides good spatial resolution [4). Although cardiac and respiratory motion considerably degrade nongated MR images of the thorax, technology is now available to allow both cardiacand respiratory-gated MR studies. A major advantage of MRI of the thorax is its ability to display sagittal and coronal planes without relying on cumbersome patient positioning or reformatting of multiple transverse slices as in CT [5, 6]. The vertical orientation of viscera and vessels within the mediastinum is ideally suited to imaging in these planes, which may be considered analogous to the standard radiographic posteroanterior (PA) and lateral views of the chest. Since radiologists and clinicians alike are thoroughly familiar with thoracic anatomy in these planes, it would seem desirable to adopt coronal and sagittal MR images as the standard projections for MRI of the thorax, reserving axial and oblique projections for situations in which they may provide additional information. To this end, we describe normal sagittal and coronal anatomy of the thorax and illustrate some examples of pathology in these planes.