Presentation on theme: "Imaging the Traumatized Patient MI Zucker, MD"— Presentation transcript:
1Imaging the Traumatized Patient MI Zucker, MD The CERVICAL SPINEImaging the Traumatized PatientMI Zucker, MD
2A dr Z Lecture …on imaging cervical spine trauma. With much gratitude to Jack Harris, MD.
3Michael I. Zucker, MD Professor, Dept. of Radiology Faculty, Dept. of Emergency MedicineUCLA Medical Center, David Geffen School of Medicine at UCLA
410,000 spinal cord injuries per year in USA Two-thirds are cervical cord.The monetary, physical and emotional losses are great.Our goal: Early detection of injuries to prevent or decrease neurological and mechanical damage to the spinal column.
5STABILITY: A Word or Two We talk about it, but what is it?A useful definition: An injury is STABLE if putting the spinal column through normal range of motion does not increase neurological or mechanical deficits.
6Three Column Theory of Denis Spinal column divided into an ANTERIOR, MIDDLE and POSTERIOR column.Injury to one column is stable, two or three are unstable.
7ANTERIOR COLUMNThe anterior longitudinal ligament, anterior 2/3 of the body and disc.
8MIDDLE COLUMNPosterior longitudinal ligament and posterior 1/3 of body and disc.
9POSTERIOR COLUMNThe posterior osseous arch and ligaments.
10DOES IT WORK?If two or three columns injured, lesion is unstable: Works well for C3 to T1.Does not work so well for C1-2, so consider most or all injuries here unstable.
11HOW DO YOU IMAGE THE CERVICAL SPINE? Plain films?CT?MRI?A combination of modalities?Is there a consensus?
13My Opinion:O*pin*ion: A belief held with confidence, but not substantiated by proof.
14Imaging Minor TraumaLATERAL view from skull base through at least the top one-half of T1. May need to supplement with Swimmer’s view.Anterior-posterior (AP)Open Mouth Odontoid (OMO)If patient is not in cervical collar: Adding Oblique views is an option.
16Imaging Major Blunt Trauma Cross-table LATERAL plain film in Trauma Suite.CT entire cervical spine.MRI also in selected cases.If you wish, AP, OMO, and Swimmer’s views also -- IF they DO NOT cause delay.CT: Axial sections base of skull through T1- AND- Sagittal (like a lateral) and Coronal (like AP and OMO) reformatting.
17MAJOR TRAUMA: Imaging Cross-table Lateral in Trauma Suite CT Base of skull through T1
18Swimmer’s View in Major Trauma A SUPPLEMENTARY view to see C7-T1 in lateral projection. NOT a substitute for a bad lateral. One arm must be elevated, so THEORETICALLY could worsen a mechanical or neurological injury.A state-of-the-art CT sagittal reformat is preferable: don’t need to move patient and imaging easier and better.
19CT Axial sections from base of skull through T1. ALWAYS do the ENTIRE cervical spine.DON’T do selective imaging with modern scanners.
20CT: Sagittal Reformatting Reconstructed by computer from axial data: no additional imaging needed.Outstanding “lateral/swimmer’s” imaging.
22MRI Gold standard for cord, thecal sac, nerve root and disc injuries. Very good for ligament injuries.Fairly good for fractures, but does miss some. CT much better.
23NEUROLOGIC DEFICITIn my view, ANY neurologic deficit, extant or transient, is MAJOR trauma, and will need CT followed by MRI.
24Any abnormality on Plain Films or worrisome examination: do CT! Remember: Fractures often come in 2’s and 3’s. The more serious injury may be the one that is occult.
25ARE THERE RISKS?Ionizing radiation can damage cells. Younger people are more susceptible than older people. Their cells are more sensitive and they have longer to manifest somatic or genetic damage.The radiation dose is significantly higher in CT than in plain films.As in most decisions in medicine, one must weigh the risks versus the benefits.
26My Approach to Success in Image Interpretation Know what to order.Know what an optimal imaging series is and don’t accept less.Read by check list.Know the common lesions.Know the commonly MISSED lesions.
27Remember: The lesions are the SAME regardless of the imaging modality Plain films are still the most common modality.If you learn on them, you can translate your knowledge to CT and MRI.
28PLAIN FILM Series LATERAL ANTERIOR-POSTERIOR (AP) OPEN MOUTH ODONTOID (OMO)*REVERSE WATERS*SWIMMER’S*OBLIQUES
30LATERAL viewThis is your MAIN view where 90% of injuries are detected.You MUST see T1. If not seen, do Swimmer’s view, unless not safe to do so.You did lateral and Swimmer’s and still no luck? DON’T QUIT: DO CT! Once you start an exam you must complete it.
31LATERAL View: First Survey Look for gross fracture or dislocation.Count vertebrae.Look at skull, entire airway and adjacent soft tissues.
32LATERAL View: Prevertebral Soft Tissues Contour is more important than measurements: straight or concave anteriorly, except at larynx.Top normal limits: C2 6mm; C6 22mm for adult, 14mm for young child.
33LATERAL View: Alignment Anterior body line.Posterior body line.Spino-laminar line (called posterior cervical line at C1-3).
34LATERAL View: Alignment Turning the lateral view HORIZONTALLY can help detect subtle malalignment.
35LATERAL View: Spaces Disc spaces: too wide, too narrow, not uniform? Facet joints: too wide, not uniform?Interspinous distances: too wide, too narrow, not uniform?
36LATERAL View: C1 and C2Basion-dens distance: average 8mm, top normal 12mm.C1: Anterior and posterior arch.C2: Dens, Harris’ ring, body especially ant/inf corner, pars and posterior arch.
37LATERAL VIEW: Predental Space In an adult, upper normal is 2.5mm. Space is parallel or narrow “V” shape.In a young child, upper normal is 4.5mm.
39LATERAL View: C3-T1Body: loss of straight or concave anterior contour, loss of height?Posterior arch: subtle cortical irregularity, overt fracture line?
40LATERAL VIEW: Child Vertebral bodies are bullet shaped. Physiologic pseudosubluxations are common, especially C2-4.Predental space is wider.Lymphoid tissue makes soft tissues more prominent.
41SWIMMER’S View A supplemental view to see C7-T1. Must raise one arm. Probably not a good idea if neurologic deficit, altered level of consciousness, upper arm injury. Could worsen an injury.
42ANTERIOR-POSTERIOR View Look at first few ribs, sterno-clavicle junction, lung apices.Contour of lateral margins of lateral masses.Uncovertebral joints.Alignment and contour of spinous processes.Position and contour of trachea.
43The ODONTOID Views Open Mouth Odontoid (OMO) is main view. Reverse Waters view is supplementary, to see top half of dens ONLY.
44OMO C1-2 lateral mass alignment of lateral margins. Dens: cortical margin irregularities, fracture lines, tilt.Upper body of C2 for fracture lines.Mach lines can be confusing.
45The INJURIES C1 and C2: by anatomic location C3 to T1: by mechanism of injury(Modified from the classification of John Harris, et al.)
46The Atlas and the AxisC1 and C2 injuries differ from the rest of the cervical spine and are considered separately.Although controversial, best to consider ALL C1 and C2 injuries as UNSTABLE in the acute trauma setting.
47Occipital-atlantic Injuries Occipital condyle fractures: lateral bending, uncommon, seen only on CT.Occipital-atlantic dissociation (OAD): rare distraction injury, usually fatal. Basion-dens distance is abnormal, 12+mm.
48The ATLAS: C1 Anterior arch fracture: extension, uncommon. Posterior arch fracture: extension, more common.JEFFERSON fracture: axial load, common
49C1: Isolated Arch Fractures Anterior archPosterior archCAUTION: You may be dealing with a Jefferson fracture with occult components: Best to CT all C1 fractures.
50JEFFERSON Fracture: C1 Axial load (“burst”) injury Pure (4) or variant (2 or 3) fractures, involving both ant. & post. arches of C1Cord injury in 15%Lateral view: anterior and posterior arch fracturesOMO view: lateral displacement of C1 lateral masses
51JEFFERSON Fracture: C1The lateral masses of C1 and C2 must be aligned on the OMO view.1-2mm of lateral displacement on one side and an EQUAL medial displacement on the other is head rotation.ANY other pattern: lateral displacement on both sides or lateral on one side, and none on the other is abnormal.
52JEFFERSON Fracture CT Classical Jefferson: 4 fractures, 2 ant./2 post. Jefferson variants: 2 or 3 fractures, but at least 1 ant. & 1 post.
53The AXIS: C2 Dens fractures Pars fractures Extension teardrop fractures
54DENS Fractures Type I: alar ligament avulsion of the tip; rare. Type II: the dens excluding the tip; 2/3.Type III: high C2 body; 1/3.Mechanism of Type II and III is controversial.
55TYPE II Dens FractureInterrupted cortical margin, lucent fracture line, tilt especially anteriorCord injury in 15%Delayed or non-union 50+%
57TYPE III Dens FractureInterrupted Harris ring, fat C2, lucent fracture line, tilt especially ant.Cord injury in 15%Heals well.
58C2: PARS Fracture Called Hangman’s or pedicle fracture, both wrong. Extension injury.Cord injury in 15%.Non-displaced, displaced, subluxed.
59C2: Extension Teardrop Fracture Avulsion by the anterior longitudinal ligament of the anterior-inferior corner of the body.Extension mechanism.Cord injury is low.
60C3 to T1These levels are so similar they will be considered as a unit.The injuries are grouped by mechanism into “families”.
61Flexion Flexion-rotation Extension Axial loading The “FAMILIES”FlexionFlexion-rotationExtensionAxial loading
62“FAMILY FLEXION” Motto: “Anterior impaction, posterior distraction.” Family members:Wedge compression fractureHyperflexion sprainBilateral interfacetal dislocationHyperflexion teardrop fracture-dislocationSpinous process fracture
63Wedge Compression Fracture Anterior-superior margin of the body is fractured.If loss of height less than 50%, one column injury and so stable.If height loss greater than 50%, posterior ligaments presumed torn and so 3 column unstable injury.If 3 bodies fractured, unstable even if less than 50% height loss each.
64Hyperflexion SprainTear of the posterior (stable), posterior/ middle (unstable) and posterior/ middle/ anterior (unstable) ligaments without fracture.One column stable, 2 or 3 unstable.Delay in healing with eventual surgical fusion fairly common.Can be a difficult diagnosis.
65Flexion-Extension Films May be helpful in ligament injuries-but are-Frequently useless due to muscle spasm
66Flexion-Extension films Rules: Patient must be alert, awake, not intoxicated, able to sit or stand, able to understand commands, and without neurologic deficit.
67It is an Active, patient-generated STRESS TEST NEVER “help” the patient to “improve” ROM.NEVER do passive ROM: this is a neurosurgical procedure done under fluoroscopic control and is controversial.
68MRI Gold Standard for spinal canal, cord, disc lesions. Silver Standard for ligament injuries, but there is no Gold and much better than plain films, CT, and flexion/extension.
69Bilateral Interfacetal Dislocation BID, also called “locked facets” is anything but locked. It is a severe 3 column injury that is completely unstable.Cord is injured in 2/3.Body is subluxed anteriorly at least 50%.Marked posterior distraction.
70Hyperflexion Teardrop Fracture- dislocation Among the worst survivable injuries, with nearly 100% severe cord lesion.Completely unstable.Little chance of neurologic improvement.
74FLEXION-ROTATION Injuries Unilateral Interfacetal Dislocation and Fracture-dislocation
75Unilateral Interfacetal Dislocation UID is not stable, as the contralateral capsule ligaments are torn.Cord injury is uncommon, but root injury is common, and HNP also occurs.Findings can be subtle: less than 50% subluxation, malalignment of spinous processes.
76CT: This is a normal facet joint, normal “hamburger sign”
77UID CT: UID has “reversed hamburger sign” of facet joint. CT is also more sensitive for associated lateral mass fractures.
80Posterior Arch Fractures Plain films are insensitive, CT is outstanding.Isolated: pedicle, lateral mass, lamina or spinous process.Multiple fractures are common. Pedicle/lamina fractures cause free-floating lateral mass.May be additional element of lateral bending.Stability depends on what is fractured.
81Extension Teardrop Fracture Avulsion fracture caused by anterior longitudinal ligament.Vertical narrow fracture of anterior-inferior corner of body.Most common site is C2.Unstable.
82EXTENSION Fracture- dislocation More severe force fractures the body along end plate and causes subluxation, usually posterior.Fracture is oriented longitudinally, and there is malalignment of the bodies.
83AXIAL Loading “Burst” fractures explode the body. All are very unstable and cause cord injury in 2/3 (except C1).There is usually an element of flexion also.
84BURST FracturesOn lateral, body is compressed anteriorly, inferior end plate often fractured, posterior body contour is convex.On AP, body fracture is vertical or oblique and pedicles spread.
85BURST FracturesCT more accurately displays the fracture pattern and the very important degree of narrowing of the spinal canal.
86REMEMBER: CT is much more sensitive for fractures than plain films. MRI is the standard for soft tissue injuries.
87GOODBYE AND GOOD IMAGING! Copyright 2004M. I. Zucker