Of all our human resources, the most precious is the desire to improve!
As the technology has improved, the anatomy and to some extentthe physiology have become better seen and understood. However,still some of these findings are not well understood and oftenhave very little written about them. Many times, interesting casesare seen by the individual or group practitioners but not availableto the general medical/legal public due to the long delays necessaryin preparing these for case presentations at conferences or forpublication or due to the fact that the physicians involved inthe interpretation of these interesting studies are not orientedtowards that type of presentation. Large volumes of imaging studiesare interpreted by Dr. Powers, and many findings that are seenare not necessarily reported or acted upon by many physicians.Also there can be significant differences in opinions in relationshipto specific findings or methods of treatment. For instance, theEuropean community may think differently on the etiologies ofback pain compared to the American community, i.e. "extensorsare in and abs are out". Yet, the American community maynot for long periods of time get such philosophical input to theextent that they modify their techniques to review data that maybe relevant to an alternative viewpoint. As Dr. Powers attendsvarious conferences and hears viewpoints, he tries to show findingsthat are relevant to these viewpoints that may be present on thescan but that are seldom looked at by other radiologists or thatare new to him that may be of interest to you. There will alwaysbe differences of opinion, however hearing these opinions fromamongst colleagues and thinking about some of the consequencesof what these findings may represent is helpful in the growthof all physicians in their understanding about health and disease.I, as a practicing Radiologist, would very much appreciate yourinput and any references that you might have available relativeto various topics presented herein that are of interest to me.Whether you agree or disagree with my findings is not the point.Personal growth does not occur unless there is a debate and furtherunderstanding of the information that we review. To do so requiresinput from colleagues. I may not always agree with your input,however from time to time, you may have significant ideas thatwill improve my understanding of what I look at as a diagnosticianand/or I may have ideas that I present to you that may help youin your practice. Thank you for your interaction.
Case I: MRI imaging as an indicator of pain:
High signal changes within bone marrow are often felt to besecondary to hemorrhage and/or more likely edema and/or granulationresponse. Articles and/or case presentations have been presentedat various conferences and in the literature that indicate thatindividuals with such findings have coincidental clinical symptomatology.
Examples are bone bruises/contusions of the knee which areoften associated with clinical symptomatology. My understandingis that prior to MRI imaging, arthrograms were often inadequatein showing this finding which may be one of the most common findingsin knee injuries. The advent of MRI imaging allowed the visualizationof these findings especially with the use of fast STIR or STIRimaging and/or fat suppressed T2 weighted images.
At a conference at the RSNA several years back, there was apresentation by the Mayo Clinic staff on ankle injuries. Theyobserved similar high signal changes in the bone marrow aboutthe ankle and foot. In the question period at the end of the lecture,I asked whether these individuals were known to have clinicalsymptoms when they had such findings and the answer from the facultywas that all patients that they knew of that had such findingswere clinically symptomatic.
Similarly, a recent search of the literature on the NationalLibrary of Medicine, Grateful Med resource shows that Schmorl'snode complexes which are known to represent vertical decompressiondisc herniations through adjacent vertebral body end plates, previouslyfelt to be relatively benign insignificant findings representingmarkers for trauma were in fact significant in some individualscausing symptomatology. This study out of Korea noted that individualswho had edema/granulation response about their Schmorl's nodecomplexes were symptomatic and that when this bone change resolved,they became asymptomatic.
It also has been my experience that a significant subset ofindividuals with shoulder evaluations have edema/granulation responsein the distal clavicle and acromial process about the acromioclavicularjoint. Some of these are very significant and light up substantiallyand probably represent the significant etiology for the patient'sclinical symptoms. It has never been explained to me exactly whythese people develop these types of findings about their acromioclavicularjoint but nonetheless, I presume that they are extremely symptomaticwith or without the presence of an acromioclavicular joint effusion.
I would appreciate your input. If you have specific imagesthat are helpful in showing this process or references that indicatewhat the high signal changes within the bone marrow represent;the etiology of such findings, i.e. hemorrhage, edema or granulationdepending on the joint (these references will be added to thispresentation as they are accumulated); why these findings occur- such as in the acromioclavicular joint; whether or not thesefindings are associated with clinical symptoms. Please do notforget to put your telephone number or E-mail address so thatfurther correspondence can occur.
For more information, please feel free to Email Dr. Powers directly.
Or contact us, toll-free at (800) 247-8624, fax (800) 272-2713
Case II: Fluid collections about the Shoulder. Thereare many different fluid collections seen about the shoulder.Some of these include:
a) Effusion of the glenohumeral joint and fluid withinthe subscapularis bursa - connected with the glenohumeral joint.
b) Effusion of the acromioclavicular joint.
c) Subacromial/Subdeltoid bursitis or fluid accumulation.
d) A Anterior Clear Space fluid.
e) A Perilabral Cyst.
f) A Ganglion Cyst especially in the area of the spinoglenoidfossa or suprascapular notch.
g) Other fluid collections.
Unfortunately, there are few good review articles that tietogether all the different fluid collections, showing examplesand explaining to you where these are and what they represent.Additionally, there is oftentimes a lack of clarity in terminologyand thus such areas as subcoracoid fluid collection versus perilabralcystic areas versus subscapularis fluid collections, etc. Manypeople have individual case examples of unusual fluid collectionswhich they may or may not have proven and yet, these are not necessarilyreadily available for review by other colleagues.
Thus, I present to you several fluid collections that I havein my teaching file and will add additional fluid collectionsas this file expands. If you have other interesting fluid collectionimages or references, I would appreciate putting them on thisreview along with the differential diagnosis and a descriptionof anatomy.
Case III: Fluid Collectionsabout the Knee.
Case IV: Herniated LumbarDisc.
It is my understanding that there are three types of herniateddisc:
a) The Protrusion which is the contained discherniation in which the radial annular tear extends near the surfacebut does not rupture through it.
b) An Extrusion in which the rupture occurs throughthe surface of the annulus.
c) A Free Fragment or Sequestration in whicha piece of the herniated extrusion has broken off from the maindisc mass and is either adjacent to or has migrated away fromthe site of tear through the annulus.
It is my understanding that protrusions represent small discherniations versus extrusions that tend to be larger and morelobulated or rounded. It is my understanding that it is oftenvery difficult to differentiate small protrusions from extrusions.Occasionally, it is quite obvious that the herniated materialis multi-lobulated or segmented and thus, presumably an extrusion,although there is a tremendous amount of overlap since when lookingat the sagittal plane oftentimes disc herniations can angle downward,upward or in both directions above and below the disc level behindthe vertebral body and yet it is still unclear whether they areprotrusions or extrusions in my mind. Perhaps you think otherwiseand can explain. There are some individuals that look at the widthof a disc extension or the length and width of its neck and tryto differentiate extrusions from protrusions, but that does notseem to always answer the questions for me.
A controversy exists regarding and the cause is aging of adisc injury where high signal changes are within the posterioraspect of the disc. It is my understanding that the outer annulushas torn or is compromised when high signal is seen within theouter annular margins. These areas of compromise/tearing can representradial or curvilinear tears. Sometimes they appear linear, andsometimes they look punctate. These tears or rents can fill upwith fluid or scar tissue and/or healing changes such as granulation.To me, these changes represent visualization of injury to thedisc annulus and represent a more enhanced visualized state ofdisc injury, although perhaps in those cases in which the discdoes not have visualized high signal, the injury can be just asgreat of not greater but less well visualized. Some physicianshave tried to use the KISS (keep it simple stupid) method of interpretingdisc disease by indicating that high signal changes representan acute disc herniation. Yet, my experience does not supportthis. As a matter of fact, in a recent case in an adversarialsituation in which a physician took the position that high signalchanges were demonstrative of acute disc herniations whereas lowsignal changes represented a chronic old disc herniation, thehigh signal changes were noted one and three years after the acuteinjuries. Search of the literature through the Grateful Med: NationalLibrary of Medicine showed a single article from South Korea thatindicated that these individuals found after surgery that thehigh signal changes represented granulation tissue within a tornannulus. The question becomes how long does it take for the granulationto begin to form, and how long does it last before it becomespermanent scar tissue that is not particularly physiologic orreactive? Furthermore, could chronic scar tissue also have a differentsignal intensity than the surrounding desiccated annulus and thusalso be high in signal intensity? Is it also not possible thatwith more acute injuries, the tear fills up with fluid? Althoughthe adversarial physician indicated that the reason for the highsignal changes in acute disc herniations is swelling, I am notaware of any vascular complex within the outer annulus to allowfor such swelling but yet it is clearly known that with acutedisc injury, the release of enzymes, acids and inflammatory mediatorsoccur and thus, migration of fluid into a tear may occur. However,I am not aware of annular tissue that is untorn to become morewater-logged or filled with these enzymes or acid baths and assuch become high in signal intensity without underlying tear ormaceration present. What are your thoughts and do you have anybackup for your positions? Enclosed are a few examples of discherniations:
1. Can one date a disc herniation and why?
2. What do the high signal intensity changes within the posteriormargin of the disc mean?
3. Do you have any method to categorize disc herniations outsideof the three categories that I have named above?
1. Any information relating to the questions above.
2. Any references that indicate why a disc herniation has highsignal intensity within it and what the high signal represents.
3. Any explanation or literature that would show the lengthof time it takes for the high signal to develop and how long itis persistent for.
4. Anything that you know of that would help age a disc injury.
For more information, please feel free to Email Dr. Powers directly.
Or contact us, toll-free at (800) 222-6768, fax (800) 272-2713
Case V:High signal changes within the vertebral bodies adjacent to discspaces and high signal changes within the central portion desiccateddisc.
Recently, I have seen a multitude of cases in which patientshave had high signal within the central portion of the disc. Althoughin theory, one could have a desiccated disc anteriorly and posteriorlywith normal non-desiccated disc centrally, given the circumstancesof the images, this was felt not to be the cause. Instead, itwas felt that there was pathology going on within the centralportion of the disc. The signal intensity was such that a largepocket or hole in the disc was unlikely from my perspective. Presumably,some form of fluid infiltration or cellular infiltration was present.Although presumably an inflammatory or infectious discitis oughtto be considered, it was presumed by me that this was a very unlikelypossibility and that more than likely this represented some otherphenomenon be it deteriorative or traumatic.
Coincidentally, in some patients, there was edema/ granulationresponse in the adjacent vertebral bodies to a limited extent.Although like Modic came up with a grading system for degenerativechanges to vertebral bodies including a granulation phase beforebony sclerosis or fatty infiltration, I contend that there areother causes for this phenomenon including the slow clearanceof enzymes, acids and inflammatory mediators often released atthe time of disc injury and persisting for periods of time. Itis my impression that these changes can take months or years tobecome visible on MRI examination. At the World Congress of LowBack Pain presented in San Diego several years ago, there wasa documentary film presented on a German physician who cured patientsby apparently injecting saline solution in or about their injurysites. These patients would give wonderful testimonials on howgreat this doctor was. Although many in the audience felt thatthis doctor may represent a type of quack, I felt that physiologicallythere may be some justification and explanation for the changesoccurring in this patient. That is that after trauma for whateverreason in specific individuals, the injured tissue is bathed inan inflammatory solution. By removing that irritant solution suchas with normal saline, it allows the tissue a chance to heal andthus the clinical symptomatology resolves. Thus, the high signalchanges seen within the vertebral body bone marrow may very wellrepresent a marker for pathologic physiology related to clearanceof these abnormal chemical agents. It may be that these agentsalso are transmitted into or evolve from the disc chemistry andare seen as the high signal changes within the central portionof the disc. As such, these in a way represent an inflammatorydiscitis. Given that bone bruises/contusions within the knee,edema/granulation response about the acromioclavicular joint ofthe shoulder and abnormal bone marrow changes in the ankle, etc.,are often associated with clinical symptoms and given that ithas been written up the Schmorl's node complexes surrounded byedema/granulation response can by symptomatic, these changes apparentlyrepresent physiologic markers of derangement with the probabilitythat this patient is symptomatic at these levels.
1. Does anybody know of any written explanation for these findingsboth in the bone marrow and in the disc in relationship to chemicalchanges causing physiologic disturbances and resulting in clinicalsymptoms?
2. Does anyone have a good explanation for the high signalchanges within the central portion of the disc? Beside just namingthe reason, can you explain the pathophysiology of how it occurs?
3. Has anybody sampled or seen evidence of sampled disc ofthese types that might prove what these discs or vertebral bodiesthat might help prove what ............ended.............
c) Topic Articles - Thefollowing articles have been written by me over time that maybe of interest to you. If you have comments or questions, pleasedo not hesitate to E-mail me or fax your request.
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