Basic Planes In Cross-Sectional Anatomy

The human body may be sectioned in one of three planes relative to a three main coordinates system (X-Y-Z). The transverse (or axial) section form a series of slices that run from top (superior) to bottom (inferior) dividing the body in superior and inferior parts. When I go to the International Hose of Pancakes IHOP for short, I am always thinking in an axial plane.

Coronal sections follow a front to back fashion splitting the body in an anterior and posterior portions while a sagittal section divides the body into left or right. There is a median plane that divides the body in two equal halves, every plane parallel to it will be consider a parasagittal plane.



Blue= Coronal Plane
Yellow=Axial Plane
Fushia= Sagittal Plane

Approaching Cross sections and Diagnostic Images.

At some point, you will be in front of a cross-section or a CT scan and you may ask yourself 'what a hell I am looking at?'. You will be ask to identify the structure marked by the arrow or arrows and you have to come with an answer. For some of you this may be the first time and you will say that Dr. Lopez is crazy. Yes, you will be expected to analyze the normal anatomy in a diagnostic image; so how do you start?

The following are a number of steps that will help you to identify structures within a cross-section. This approach should be follow and practice every time you see a cross-sectional image.

1. Make sure that you understand the imaging method (CT, MR or X-ray)
2. Recognize the plane, is the image shown in the axial, coronal or sagittal plane?
3. Identify the anatomical region. Where are you? in the thorax or in the abdomen.
4. As soon as you know were you are, identify the level, are you distal or proximal? near the apex or at the base of the thorax.
5. Know the relationships of the different organs within the plane.

I hope this tips help you to learn and analyze the images.

Best regards,

Hector Lopez, M.D.