You had an MRI and the doctor is explaining your injuries in all sorts of medical terms… but what do they mean?!??  Here is a quick reference to help you understand the meaning of those terms.  The terms, as defined below, come directly from the Nomenclature and Classification of Lumbar Disc Pathology - Recommendations of the Combined Task Forces of the North American Spine Society, American Society of Spine Radiology, and American Society of Neuroradiology as published by David F. Fardon, MD and Pierre C. Milette, MD and endorsed by the Board of Directors of the North American Spine Society (NASS), the Executive Committees of both the American Society of Spine Radiology (ASSR) and American Society of Neuroradiology (ASNR), and the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons (AANS) and Congress of Neurological Surgeons (CNS), and the CPT and ICD Coding Committee of the American Academy of Orthopaedic Surgeons (AAOS).These terms focus on the discs in the lumbar spine, although they can easily be extrapolated to the cervical and dorsal spine.  Each disc can be classified in terms of one, and occasionally more than one, of the following diagnostic categories:

NORMAL - means the disc is fully and normally developed and free of any changes of disease, trauma or aging.  Only the morphology (portion of biology that refers to the size, shape and structure rather than the function) is considered, not the clinical context.  Commonly, people with a variety of harmless congenital, degenerative or adaptive or developmental variations of discs, minor bulging of anuli, normal aging, scoliosis, spondylolisthesis, anterior and lateral marginal vertebral body osteophytes are normal people.  By this nomenclature and classification, however, such individual discs are not considered “normal.”  Thus some people are clinically “normal” even though they have morphologically abnormal discs.

CONGENITAL/DEVELOPMENTAL VARIATION - includes discs that are congenitally abnormal or that have undergone changes in their morphology as an adaptation to abnormal growth of the spine such as from scoliosis or spondylolisthesis.

DEGENERATIVE/TRAUMATIC - these types of change in the disc are included in a broad category that includes subcategories of Anular Tear; Herniation; and Degeneration. Characterization of this group of discs as Degenerative/Traumatic does not imply that trauma is necessarily a factor or that degenerative changes are necessarily pathologic as opposed to the normal aging process.

• Annular Tears, also properly called anular fissures (primarily for fear that the word “tear” could be misconstrued as implying a traumatic etiology), are separations between anular fibers, avulsion of fibers from their vertebral body insertions, or breaks through fibers that extend radially, transversely, or concentrically, involving one or many layers of the anular lamellae. The terms “tear” or “fissure” describe the spectrum of such lesions and do not imply that the lesion is consequent to trauma. In the case where a single, traumatic event is clearly the source of loss of integrity of a formally normal anulus, such as with documentation and findings of violent distraction injury, the term “rupture” of the annulus is appropriate, but use of the term “rupture” as synonymous with commonly observed tears or fissures is contraindicated.
• Herniation is defined as a localized displacement of disc material beyond the limits of the intervertebral disc space (craniad and caudad, by the vertebral body endplates and, peripherally, by the edges of the vertebral ring apophyses, exclusive of osteophytic formations). A herniated disc is often also called a herniated nucleus pulposus (HNP), which is inaccurate because materials other than nucleus (cartilage, fragmented apophyseal bone, fragmented annulus or anular tissue) are common components of displaced disc material; ruptured disc, casts an image of tearing apart and therefore carries more implication of traumatic etiology than “herniation,” which conveys an image of displacement rather than disruption; protruded disc used in a nonspecific general sense to signify any displacement has amore commonly used specific meaning for which it is best reserved; prolapsed disc which has also been used as a general term, as synonymous with the specific meaning of protrusion, or to denote inferior migration of extruded disc material, is not commonly used and is best proscribed; and bulging disc has been used to mean many things and has caused a great deal of confusion; or even “disc material beyond the interspace” (DEBIT).  The disc material may be nucleus, cartilage, fragmented apophyseal bone, anular tissue, or any combination thereof. The disc space is defined, craniad and caudad, by the vertebral body endplates and, peripherally, by the outer edges of the vertebral ring apophyses, exclusive of osteophytic formations. The term “localized” contrasts to “generalized,” the latter being arbitrarily defined as greater than 50% (180 degrees) of the periphery of the disc. Localized displacement in the axial (horizontal) plane can be “focal,” signifying less than 25% of the disc circumference, or “broad-based,” meaning between 25 and 50% of the disc circumference. Presence of disc tissue “circumferentially” (50-100%) beyond the edges of the ring apophyses may be called “bulging” and is not considered a form of herniation, nor are diffuse adaptive alterations of disc contour secondary to adjacent deformity as may be present in severe scoliosis or spondylolisthesis. Herniated discs may take the form of protrusion or extrusion, based on the shape of the displaced material.  Further distinctions can often be made regarding containment, continuity, volume, composition, and location of the displaced disc material.
  • Protrusion is present if the greatest distance, in any plane, between the edges of the disc material beyond the disc space is less than the distance between the edges of the base, in the same plane. The base is defined as the cross-sectional area of disc material at the outer margin of the disc space of origin, where disc material displaced beyond the disc space is continuous with disc material within the disc space. In the cranio-caudal direction, the length of the base cannot exceed, by definition, the height of the intervertebral space. Protrusions may be “focal” or “broad-based.” The distinction between focal and broad-based is arbitrarily set at 25% of the circumference of the disc. Protrusions with a base less than 25% (90 degrees) of the circumference of the disc are “focal.” If disc material is herniated so that the protrusion encompasses 25% to 50% of the circumference of the disc, it is considered “broad-based protrusion.”
  • Extrusion is present when material is forced from one domain to another through an aperture - when, in at least one plane, any one distance between the edges of the disc material beyond the disc space is greater than the distance between the edges of the base, or when no continuity exists between the disc material beyond the disc space and that within the disc space. Extrusion may be further specified as sequestration, if the displaced disc material has lost completely any continuity with the parent disc. A sequestrated disc is a subtype of “extruded disc” but, by definition, can never be a “protruded disc.” The term migration may be used to signify displacement of disc material away from the site of extrusion, regardless of whether sequestrated or not. The term migration is often used in the interpretation of imaging studies because it is often impossible from images to know if continuity exists Because posteriorly displaced disc material is often constrained by the posterior longitudinal ligament, images may portray a disc displacement as a protrusion on axial sections and an extrusion on sagittal sections, in which cases the displacement should be considered an extrusion.
  • Intravertebral Herniations are discs in the cranio-caudal (vertical) direction through a break in the vertebral body endplate. Disc herniations may be further specifically described as contained, if the displaced portion is covered by outer anulus, or uncontained when absent any such covering. Displaced disc tissues may also be described by location, volume, and content, as discussed later in this document. 
  • Containment/Continuity - Herniated disc material can be “contained” or “uncontained.” The test of containment is whether the displaced disc tissues are wholly held within intact outer anulus. A disc with a “contained” herniation would not leak into the vertebral canal fluid that has been injected into the disc. Although the posterior longitudinal ligament and/or peridural membrane may partially cover extruded disc tissues, such discs are not considered “contained” unless the outer anulus is intact. Strictly speaking, containment refers to the integrity of the outer anulus covering the disc herniation. The technical limitations of currently available noninvasive imaging modalities (CT and MRI) usually preclude the distinction of a contained from an uncontained disc herniation. Discography does not allow one to distinguish a containing capsule consisting of both anular fibers and longitudinal ligament fibers from one consisting only of longitudinal ligament fibers, and essentially only allows one to separate a “leaking disc” from a “nonleaking disc.” Displaced disc fragments are sometimes characterized as “free.” A “free fragment” is synonymous with a “sequestrated fragment” and not the same as “uncontained,” as the latter refers only to the integrity of the outer anulus and has no inference as to the continuity of the displaced disc material with the parent disc. A fragment should be considered “free,” or “sequestrated,” only if there is no remaining continuity of disc material between it and the disc of origin. The term “migrated” disc or fragment refers to displacement of disc material away from the opening in the anulus through which the material has extruded. Some migrated fragments will be sequestrated, but the term migrated refers only to position and not to continuity. Referring to the posterior longitudinal ligament (PLL), some authors have distinguished displaced disc material as “subligamentous,” “extraligamentous,” “transligamentous,” or “perforated.” When the distinction between the outer anulus and the PLL is unclear and a fragment is under such a blended structure (sometimes called “capsule”), it has been called “subcapsular.” If the peridural membrane alone surrounds the displaced disc material, the displacement is sometimes called “submembranous.” Such permutations of continuity, containment, and relationships to ligaments and membranes are refinements that may suit certain purposes but do not supersede the basic definition of disc herniation and the major subcategorizations of extrusion and protrusion.
  • Volume and Composition of Displaced Material - to define the degree of canal compromise produced by disc displacement measurements are taken from an axial section at the site of the most severe compromise. Canal compromise of less than one third of the canal at that section is “mild”; between one and two thirds is “moderate”; and over two thirds is “severe.” The same grading can be applied for foraminal involvement. Such characterizations of volume describe only the cross- sectional area at one section and do not account for total volume of displaced material, proximity to, compression and distortion of neural structures, or other potentially significant features, which the observer may further detail by narrative description. Composition of the displaced material may be characterized by such terms as “nuclear,” “cartilaginous,” “bony,” “calcified,” “ossified,” “collagenous,” “scarred,” “desiccated,” “gaseous,” or “liquefied.” 
  • Location - anatomic “zones” and “levels” are defined using the following landmarks: medial edge of the articular facets; medial, lateral, upper, and lower borders of the pedicles; and coronal and sagittal planes at the center of the disc. On the horizontal (axial) plane, these landmarks determine the boundaries of the “central zone,” the “subarticular zone,” the “foraminal zone,” the “extraforaminal zone,” and the “anterior zone,” respectively. On the sagittal (craniocaudal) plane, they determine the boundaries of the “disc level,” the “infra-pedicular level,” the “pedicular level,” and the “supra-pedicular level,” respectively. The method is not as precise as drawings depict because borderlines such as the medial edges of facets and the walls of the pedicles are curved, but the method is simple, practical, and in common usage. Moving from central to right lateral in the axial (horizontal) plane, location may be defined as “central,” “right central,” “right subarticular,” “right foraminal,” or “right extraforaminal.” The term “paracentral” is less precise than defining “right central” or “left central,” but is useful in describing groups of discs that include both, or when speaking informally when the side is not significant. For reporting of image observations of a specific disc, “right central” or “left central” should supersede use of the term “paracentral.” The term “far lateral” is sometimes used synonymously with “extraforaminal.” In the sagittal plane, location may be defined as “discal,” “infra-pedicular,” “supra-pedicular,” or “pedicular.” In the coronal plane, “anterior,” in relationship to the disc, means ventral to the midcoronal plane of the centrum.
• Degeneration includes changes in the disc due to the pathologic degenerative processes and those due to normal aging, which may include any or all of real or apparent desiccation, fibrosis, narrowing of the disc space, diffuse bulging of the anulus beyond the disc space, extensive fissuring (i.e., numerous anular tears), and mucinous degeneration of the anulus, defects and sclerosis of the endplates, and osteophytes at the vertebral apophyses. A disc demonstrating one or more of these degenerative changes can be further qualified into two subcategories:
  • Spondylosis deformans - possibly representing changes in the disc associated with a normal aging process - affects the annulus fibrosus and adjacent apophyses;
  • Intervertebral osteochondrosis - also known as “deteriorated disc” also sometimes called “chronic discopathy,” which is possibly the consequences of a more clearly pathologic process, although not clearly symptomatic and affects mainly the nucleus pulposus and the vertebral body endplates, but also includes extensive fissuring (numerous tears) of the annulus fibrosis, which may be followed by atrophy. Radiographically, intervertebral osteochondrosis is characterized by narrowing of the intervertebral space, irregular disc contour often associated with bulging, multidirectional osteophytes often involving the central spinal canal and foramina, endplate erosions with reactive osteosclerosis, and chronic vertebral body bone marrow changes.

INFECTIOUS/INFLAMMATORY - includes infection, infection-like inflammatory discitis, and inflammatory response to spondyloarthropathy.  It also includes inflammatory spondylitis of subchondral endplate and bone marrow manifested as Modic Type 1 magnetic resonance imaging (MRI) changes and usually associated with pathologic changes in the disc.

NEOPLASTIC/NEOPLASIA - Primary or metastatic morphologic changes of disc tissues.

MORPHOLOGIC VARIANT OF UNCERTAIN SIGNIFICANCE -  Instances in which data suggest abnormal morphology of the disc but are not complete enough to warrant a diagnostic categorization can be categorized as Morphologic Variant of Unknown Significance.

This is not a fully comprehensive description.  If you have any medical questions you should consult with your treating doctor immediately.  For legal questions the Kane Law Firm will be happy to assist you.  We offer a free initial consultation and take all of our cases on a contingency free basis.  Please just call our offices today at (407) 644-KANE(5263).