Here is an example of an MRI of the thoracic spine. The image on the left is taken as if the body were being sliced from head to toe (sagittal image) and the image below is as if the body were being sliced across the middle like a loaf of bread (axial image).
The image to the left shows the vertebral bodies as blocks and the spinous processes back behind the spinal canal as obliquely oriented blades. The spinal canal on both contains the spinal cord which is mostly black surrounded by the normal cerebrospinal fluid which is white. The thoracic cord normally has a little bit of a bulge as it ends in the upper lumbar spine, seen on the sagittal image towards the bottom.
This patient presented for evaluation of mid-back pain. On the left side sagittal image, the cord has an area of white running through it centrally from top to bottom. This is seen as the central spot of white within the normally dark cord on the axial image. The signal of this area matches the signal of the cerebrospinal fluid surrounding the cord.
This area of white is one example of cord pathology that might be picked up on an MRI. This is known as a syrinx (or syringohydromyelia - how’s that for a long name!) and is an abnormal buildup of fluid in the central canal of the cord. Over time, this fluid buildup can enlarge and start to affect the nerves running through the cord, sometimes resulting in symptoms like muscle weakness.
Remember, most patients with back pain will find their symptoms resolve within 4 weeks. If symptoms do not improve or are accompanied by other changes like muscle weakness, evaluation by your doctor is warranted.
Originally published 5/21/14 on diagnosticimagingcenterskc.com.