Radiology of the Spine andMusculoskeletal SystemNRMSM 2013 3rd Year
Learning Objectives1. Understand radiological anatomy of :O Spine, cervical, thoracic and lumbarO Hip and pelvisO Lower limbs ,knee and ankle joint.O Upper limbs, elbow and shoulder, wristjoint2. Identify some basic abnormalities
Overview of lectureO IntroductionO General PrinciplesO Systematic approachO Viewing principles
IntroductionO Conventional radiographs are the most frequently obtainedimaging studies.O They are chiefly useful for evaluation of the bones, butuseful information about the adjacent soft tissues may alsobe obtained.O Gas in the soft tissues may be a clue to an open wound,ulcer, or infection with a gas-producing organism.O Calcifications in the soft tissues can indicate a tumour orsystemic disorders such as hyperparathyroidismO To get the most information possible from conventionalradiographs, you should carefully choose the study to beordered.O At most hospitals and clinics, standardized sets of viewshave been developed that are routinely obtained togetherfor evaluation of specific body areas in certain clinicalsettings.
Introduction cntndO In general, as in most other organ systems, theradiograph is the initial imaging test after historyand physical examination.O The selection of subsequent (often moreexpensive) imaging tests depends not only onmedical need but also on a variety of other factors,including availability, expense, and the preferencesof the radiologist, clinician, and patient.O Understanding the surface anatomy of the body isvital as a clinician, as we use surface anatomylandmarks to conduct various procedures.
General PrinciplesBone structureO In simple terms bone is made of an outer cortex and aninner medulla.O Difference in density allows for differentiation on X-rays -cortex being denser and therefore whiter.Descriptive termsO Once the skeleton is fused the distinction betweenepiphysis, metaphysis and diaphysis becomes less clear,and is less important.O General terms can be used to describe the location of anabnormality.Joint anatomyO Most joints are synovial and comprise two articulatingbones lined with hyaline cartilage and contained by asynovial lined capsule.O Although soft tissues such as cartilage and capsularstructures are of low density, and therefore less well-defined on X-ray images, it is a mistake to think they arenot visible.
Systematic ChecklistAlthough the system for viewing X-rays of bonesand joints varies depending on the anatomybeing examined, there are some broadprinciples which can be applied in a number ofsituationsO Patient and image dataO Bone and joint alignmentO Joint spacingO Cortical outlineO Bone textureO Soft tissues
Systematic Approach cntdPatient and image dataO Start by checking you are looking at the correctimage.O The patients details should be checked and the dateand time of the X-ray noted.O The skeletal system is symmetrical and therefore it isparticularly important to be sure you are looking atthe correct side.Bone and joint alignmentO Loss of alignment may be due to bone fracture orjoint dislocation.O Both are associated with soft tissue injury that maynot be directly visualised.
Systematic Approach cntdJoint spacingO Joint spacing may be narrowed due to cartilageloss or widened due to dislocation/dissociationCortical outlineO Careful scrutiny of the bone cortex is requiredbecause a check that is too brief will lead toincorrect or incomplete diagnosis.O In the context of trauma the clinical features of asignificant injury may be masked by other injuries.O Remember to be systematic, and if you spot oneabnormality, do not stop until you are sure youhave focussed on all areas of the anatomy shown
Systematic Approach cntdBone textureO In some bones a fine matrix of fine white lines(trabeculae) is seen.O Occasionally bone injury or disease will resultin abnormality of this texture.Soft tissuesO Scrutinising the soft tissues can often providehelpful information.O Not uncommonly an abnormality of softtissues is more obvious than a bone injury, ormay even imply a bone injury that is notvisible at all.
Viewing PrinciplesO Confidence in assessing musculoskeletal system X-rays comes from experience and a knowledge ofnormal appearances.O All patients are different, so being sure of thedistinction between normal and abnormal is oftendifficult.O Here are some principles that may help you todetermine if a finding is normalKey pointsO 2 views are better than 1O Check all available imagesO Compare with the other side (if imaged)O If available ALWAYS compare with old X-rays
Viewing Principles cntnd2 views are better than 1O In the context of trauma at least 2 views of the body part in question areusually required. If looking for specific disease entities, for example erosionsin rheumatoid arthritis, this may be less important.O In some cases, such as possible scaphoid injury, more than 2 images arerequired.Compare with other sideO Images of the asymptomatic contralateral side to a suspected abnormalityare not routinely acquired for assessment of all bones or joints.O If an old image of the contralateral side is available, or if the other side isincluded as standard (for example hip/pelvis) then comparison betweensymptomatic and asymptomatic appearances can be very helpfulO The old X-ray is said to be the cheapest test in radiology. If you areuncertain of an abnormality and there is an old image available of the areain question, then ALWAYS look at it. Doing this often increases diagnosticconfidence, and shows progression over time.
Viewing Principles cntndKeep your eye on the ballO When looking at an X-ray always keep the current clinicalfeatures at the forefront of your mind.O Remember - Treat the patient and not the X-ray!Look for the unexpectedO Not all disease that presents with skeletal symptoms is primarilyrelated to bone or joints.O Very often pain is referred to the symptomatic area and isexplained by disease of another system.O For example, shoulder pain is usually due to shoulderpathology, but always keep in mind that pain may be referred tothe shoulder from the cervical spine, brachial plexus ordiaphragm
Viewing Principles cntndImage qualityO Certain X-rays which require careful patient positioning maynot be possible due to pain or reduced patient co-operation.O High quality images may not be achievable, in which caseyou will have to work with the images provided.O If an image is sub-optimal you can ask theradiographer/technician if there were particular technicalreasons for this. Requesting a repeat image may bereasonable, if clinically justified.ArtifactO Many musculoskeletal system X-rays contain artifact, eitherdue to previous orthopaedic surgery, or due to foreignbodies relating to the injury.O If there is external artifact that obscures the area ofanatomical interest then this should be removed if possible
SPINEO Anterior-posterior full-length view of the spineand Lateral full-length view of the spineO Cervical vertebrae : Anterior viewO Cervical vertebrae : Lateral ViewO Vertebral column - Thoracic vertebrae :Anterior-posterior viewO Lumbar vertebrae
Anterior-posterior full-length view of thespine and Lateral full-length view of thespine
LOWER LIMBSO Full-length anterior-posterior weight-bearing view of the legO AP view Tibia and FibulaO Knee : AP and lateral ViewO Ankle Anterior viewO Ankle : lateral ViewO Foot Superior and lateral view
Full-length anterior-posterior weight-bearing view ofthe leg
UPPER LIMBSO Pectoral girdle; Shoulder girdle -Radiography : Anterior viewO Humerus AP ViewO Forearm radius and ulna AP ViewO Elbow Joint - Cubital region : AP andLateral viewO WRIST AP ViewO Hand Oblique View
ChecklistO Plain radiographs provide informationabout bone, joint and soft tissue structuresO Be systematicO Look at all views availableO If available compare with old imagesO Look for the unexpectedO Assess image quality and if clinicallyappropriate consider requesting a repeat