Learning MRI planning through CT
Contributed by Dr Vishnu Vardhan Ravilla and Dr Ashita Barthur
Standardised cardiac imaging planes in the shortest number of steps possible should be the ultimate goal.
The standard planes include
- Vertical Long Axis (VLA) or 2 Chamber view (2C)
- Horizontal Long Axis (HLA) or 4 Chamber view (4C)
- Parasternal long axis view (PLA) or 3 Chamber view (3C0)
- and multiple, contiguous short axis views (SAX)
CT has the advantage of a volumetric data set that can be played with to achieve any number of planes according to the anatomy of interest. It is also the more familiar and commoner modality available for cardiac evaluation compared with MRI. In this article, we have utilised CT to help understand cardiac planes and related anatomy. This understanding can be extrapolated to the planning of cardiac axes during the acquisition of cardiac MRI.
- Start with a good Cardiac CTA axial data set.
- Load the data in to any multi-planar viewer on the console or workstation and start scrolling the images in the axial plane.
At the level of the mitral valve prescribe a slice plane connecting the mitral valve (MV) to the left ventricular (LV) apex to get a 2C view.
2 Chamber View
On the acquired 2C view prescribe another slice connecting the mitral valve and the LV apex again to get a SAX view of the heart.
Short Axis view (SAX)
Now on the acquired SAX view prescribe a slice passing through the LV mid-cavity, interventricular septum and junction of RV free and inferior wall to get a 4 chamber view
4 Chamber view
In the basal SAX slice, prescribe a slice cutting through the LV, LVOT and Aortic valve. While doing so make sure that this plane is still going through the MV and LV apex plane on the orthogonal view to get a good 3 chamber view
3 chamber view
On the 3C view prescribe a slice along the LVOT, Aortic valve and the ascending aorta to get an oblique coronal LVOT view and an aortic valve view.
LVOT and Aortic Valve
