Title: Diagnostic Imaging in Musculoskeletal Injuries
1Diagnostic Imaging in Musculoskeletal Injuries
- Rodney S. Gonzalez, MD
- Primary Care Sports Medicine Fellow
- Contributors
- Leslie Rassner, MD (Slides adapted from)
- Francis OConnor, MD, FACSM
- Ulrich Rassner, MD
2Objectives
- Discuss fundamental imaging strategies for the
evaluation of site-specific musculoskeletal
injuries. - Review the various imaging modalities available
to the clinician with an emphasis on - Indications
- Limitations
- Contraindications
3Low Back Pain
- Healthy middle age male with acute onset of low
back pain after pick-up basketball game. - Adolescent female gymnast with gradual onset of
low back pain. - Middle age obese patient with history of
prolonged oral steroid use and multiple
co-morbidities s/p car accident with back pain.
4Low Back Pain
- Who will you x-ray?
- What plain film views do you want?
- When do you order a CT, MRI or CT myelogram?
- When will you order a bone scan?
5Low Back Pain
- Make a pathoanatomic diagnosis or differential
diagnosis. - Decide do we need to rule out tumor, infection,
or fracture? - Would imaging change our treatment such as
generate referral to surgeon or for epidural
steroid injection?
6Low Back Pain
- Image red flag patients
- Major trauma
- Age gt 50
- Unrelenting pain at rest or night pain
- Fever, chills, sweats
- Unexplained weight loss
- History of cancer
- Incontinence of bowel or bladder
- Progressive weakness
7Low Back Pain
- Conventional x-ray (plain films)
- AP, lateral, and lumbosacral (LS) spot view
- LS spot view
- L5 centered view eliminates
potential over-read of disk
space narrowing from beam
diversion on standard lateral - Initial view to look for disk space
narrowing, osteophytes, fracture,
tumor, or spondylolisthesis
8Low Back Pain
- Conventional x-ray (plain films)
- Oblique views best if concern for pars
interarticularis stress fracture (spondylolysis) - Pars interarticularis narrow portion of bone
- between the superior and inferior articular
facets
9Radiography
- Advantages
- Inexpensive
- Readily available
- Excellent spatial resolution
- Real-time availability as fluoroscopy
10Radiography
- Limitations
- Two-dimensional
- Relatively poor soft tissue contrast resolution
- However,
- Useful for radio-opaque foreign bodies
- Useful for soft tissue emphysema or free air
- Ionizing radiation exposure
Two orthogonal views at a minimum
11Inservice Question X-ray
- A 23-year-old male returns from a Florida beach
vacation, where he sustained a cut to his foot
while wading. - The cut wasnt treated when it happened, and it
is healing, but he says that it feels like
something in the wound is poking him. - Of the following, which one would most likely be
easily visible on plain film radiography? - A) A wood splinter
- B) A glass splinter
- C) A plastic splinter
- D) A sea urchin spine
12Radiography
- Contraindications
- Pregnancy
- Most of concern for L-spine and pelvis.
- Other areas minimal radiation exposure to fetus
with shielding.
13Low Back Pain
- Our middle age patient had no red flags. We
diagnosed him with mechanical low back pain and
started him on conservative treatment. - Six weeks out patient has no improvement in his
pain. He has symptoms of sciatica. He has
normal x-rays. - You feel an epidural steroid injection is
indicated. - What imaging study is next?
- MRI?
- CT?
- CT myelogram?
14Low Back Pain
- MRI
- Excellent for disk herniation and cord contusion
- Also will demonstrate
- Spinal cord anomalies
- Tumors
- Discitis
- Vertebral osteomyelitis
15Magnetic Resonance Imaging
- Vast, vast majority of clinical MRI utilizes the
magnetic moment of hydrogen nuclei (protons).
16Magnetic Resonance Imaging
- Advantages
- Superior contrast resolution, particularly among
soft tissues. - High degree of sensitivity in diseases involving
bone marrow. - Non-ionizing radiation (instead electromagnetic
radiation).
17Magnetic Resonance Imaging
- Limitations
- The most artifacts motion and metal.
- Claustrophobia.
- Some findings are extremely subtle, can be highly
dependent upon interpretation (ie.
glenohumeral labral pathology). - High cost.
18Magnetic Resonance Imaging
- Contraindications
- Pacemakers absolute (under investigation)
- Devices may malfunction or be contraindicated
- Cardiac valves usually safe after 6 weeks
- Stents
- Non-ferromagnetic are safe
- Ferromagnetic are safe after 6 weeks due to
epithelialization - Abdominal aortic aneurysm stents, check with
radiologist - Pumps, check with radiologist
- Get radiologists approval documented in the chart
19Magnetic Resonance Imaging
- Contraindications (continued)
- Metal foreign bodies, body piercings, and jewelry
can migrate, heat up, or torque. - Situational clearance
- Fragment in brain or eye in vast majority
contraindicated. - Bullet imbedded in femur or extremity muscle,
likely OK. - Tattoos and cosmetics can
heat up (metallic dyes)
20Magnetic Resonance Imaging
- Contraindications (continued)
- Obese patients
- Scanner table weight limits
- The gantry opening might be too small even if
patient qualifies by weight - Pregnancy
- Avoid 1st trimester
- No gadolinium unless absolutely necessary
- Animal studies conflicting
21MRI-Safety
- The field of the scanner is ALWAYS on.
- Everything that is sucked into the magnet goes
into the center, where the patient is lying. - Disregard for safety procedures can potentially
be lethal.
22Low Back Pain
- Patient has a pacemaker and some cool tattoos.
His back pain is not improving and he has
physical exam findings of nerve impingement. - What study can you do?
23Low Back Pain
- CT Scan
- Excellent for delineating bone if concern for
vertebral fracture with posterior fragment
displacement (would likely be done in conjunction
with MRI) - CT Myelogram
- Fluoroscopic guided lumbar puncture with
placement of non-ionic contrast - Indications
- You are an old-fashioned doctor
- Contraindication to MRI (or no access to MRI)
- Evaluate nerve root cysts, can determine
communication of multiple cysts by contrast fill
pattern - Carries risks of invasive procedure
24Computed Tomography
- CT uses x-rays to produce cross sectional images.
- Sir Godfrey Newbold Hounsfield
- Built first clinically utilized CT- (brain)
scanner - Nobel prize in medicine 1979, shared with Allan
Cormack
25Computed Tomography
- CT is cool!
- Images reconstruction - 2D or 3D.
- Kinematic CT - imaging of joint motion.
26Computed Tomography
- Advantages
- Higher contrast resolution of images
- Excellent images of bones and lungs
- IV contrast rarely needed for orthopedic trauma
(unless soft tissue/organ injury workup) - Wide availability
27Computed Tomography
- Limitations
- Can produce artifacts motion and metal
- More limited soft-tissue contrast than MRI
- Not as good as ultrasound for superficial
structures like rotator cuff or Bakers cyst - Ionizing radiation
- Radiation dose much higher than for conventional
radiography - Higher cost than conventional x-ray
28Computed Tomography
- Contraindications
- Scanner weight limits for obese patients
- Pregnant women should not have CT scans except in
life-threatening emergencies - Pregnant patients can be scanned with shielding
depending on body part (minimal radiation
exposure to fetus if ankle or knee is scanned)
29Low Back Pain
- Our adolescent gymnast has a pars
interarticularis defect on LS spot view. We want
to decide whether she needs back bracing. - We have a 20 y.o. male service academy athlete
with low back pain, worse on single leg extension
test, but without plain film abnormality. - What diagnosis are you concerned about?
- You have plain
- filmswhat next?
30Spondylolysis
- Defect in pars interarticularis
- Result from congenital, degenerative, traumatic,
or stress-related causes. - Approximately 5 of Caucasians have on x-ray
- Can occur with repetitive mechanical loading
- Increased incidence in football linemen and
gymnasts
31Scintigraphy/Bone Scan
- Biologically active drugs are labeled with
radioisotopes - The images produced by scintigraphy are a
collection of radiation emissions obtained with a
special camera (gamma camera) - Two principal techniques in sports medicine
- Planar (traditional bone scan)
- SPECT cross-sectional
32SPECT Imaging Single Photon Emission Computed
Tomography
Coronal
Sagittal
Axial
Posterior planar image
- Enhanced tissue contrast
- Improved sensitivity and specificity of lesion
detection - and localization
33Scintigraphy
- Advantages
- Ability to image metabolic activity
- Very sensitive to fractures and tumors
34Scintigraphy
- Limitations
- Lacks of significant detail
- Poor spatial resolution
- Poor specificity
- Displays function of osteoblasts
- Old fractures (pars defects) may not show up.
- Certain tumors with little osteoblastic activity
(multiple myeloma and lytic mets) not reliably
seen.
35Scintigraphy
- Contraindications
- Exposes patient to ionizing radiation
- Children and pregnant women should be carefully
screened
36Spondylolysis
- X-ray
- Cheap, but low sensitivity
- Not physiologic, does not determine if active
healing - Can be used for monthly f/u for observation of
healing - Scintigraphy
- Bone scan fairly sensitive, not as specific,
and does not show detailed anatomy - SPECT scan greater accuracy than bone scan and
x-ray, but expensive and not as readily available - Can not be used to follow progression of healing
as will stay positive one year - Thin section CT scan
- Sensitive and shows anatomic detail
- Must know level of concern to focus imaging
37Spondylolithesis
- Forward slippage of one vertebral body on another
due to bilateral pars defects at a given
vertebral level - Hot on bone scan, refer
- Cold on bone scan, refer only
if slip gt 25 ( gt Grade 1) for
consideration of
thoracolumbosacral orthosis
(TLSO) or surgical stabilization
38Chronic Low Back Pain
- Consider guided injections
- Fluoroscopic SI, facet injections, epidural
steroids
39Fluoroscopy
- Real-time x-ray images with digital detectors.
- X-ray source is underneath table and detector
above, thus shield needs to be placed underneath
patient.
40Questions?
41Cervical Spine Injuries
- All patients with suspected fracture need three
views - Cross-table lateral
- Anteroposterior (AP)
- Open-mouth odontoid
42Cervical Spine Injuries
- Systematic review of cervical spine radiographs
- Lateral view
- All vertebrae on the lateral
- Presence of lordosis
- Vertebral alignment
- Spinolaminal line
- Spinous processes
- Soft tissue examination
43Cervical Spine Injuries
- Systematic review of cervical spine radiographs
- Lateral view
- All vertebrae on the lateral
- Presence of lordosis
- Vertebral alignment
- Spinolaminal line
- Spinous processes
- Soft tissue examination
44Cervical Spine Injuries
- Soft tissue space r/o occult fracture
- 6 at 2 and 2 at 6
- 6mm at C2 and 2cm at C6
- C1-C3 lt 7mm
- C4-C7 14-22 mm
45Cervical Spine Injuries
- Systematic review of cervical spine radiographs
- AP view
- Spinous processes
46Cervical Spine Injuries
- Systematic review of cervical spine radiographs
- Odontoid view
- C1-2 articulation
Jefferson fracture ring of C1 broken in 4
places from axial loading
47Cervical Spine Injuries
- Dynamic flexion-extension
- Expose undetected ligament disruption
- Indicated if initial films normal, but suspicion
persists - Require alert, cooperative patient, stopping for
pain or paresthesias
48Cervical Spine Injuries
- Dynamic flexion-extension
- Widening of the predental space from rupture of
the transverse ligament. - Ligament normally holds C-1 against the dens
(odontoid) of C-2.
49Cervical Spine Injuries
- CT
- If suspicion high but plain films normal
- If signs of possible instability on plain films
- Better visualize fracture, evaluate for
displacement - MRI
- To clearly define canal compromise and/or soft
tissue injury
50Inservice Question Head
- A 15-year-old white male is being evaluated after
a fall down one flight of stairs. - He walked briefly at the scene and did not lose
consciousness. - His only complaint is a mild, generalized
headache. One episode of vomiting occurred
shortly after the accident. No weakness or
numbness has been noted. - Vital signs, mental status, and neurologic
findings are normal. - Radiologic evaluation of the cervical spine is
remarkable only for an air-fluid level in the
sphenoid sinus. - Which one of the following abnormalities is most
likely to be associated with this radiologic
finding? - A) A basilar skull fracture
- B) An orbital floor fracture
- C) An epidural hematoma
- D) A zygomatic arch fracture
- E) A mandible fracture
51Questions?
52Shoulder Injuries
53Acute Shoulder Trauma
- Acute series
- Obtained with patient as is, without moving arm
or sling. Patient can be standing, sitting, or
lying. - AP
- Lateral scapular view
54Shoulder Injury
- Standard series
- Internal and external rotation AP
- Axillary view
55Shoulder Injury
- Views
- True AP
- Arm held in slight internal rotation
- Identify greater tuberosity fractures
- Hill-Sachs lesion
- Impression defect on
posterolateral aspect
of humeral head - Can miss posterior
- dislocation
56Shoulder Injury
- Views (continued)
- Supraspinatus outlet view, scapular lateral view,
or Y view - Direction of dislocation and angulation of
proximal humerus fractures - Good view when patient discomfort/injury prevents
axillary view - Axillary views
- Acromial and coracoid fractures
57Shoulder Injury
- MRI and MRI arthrography
- Nonsurgical diagnostic test of choice for
internal derangements and structural instability
assessment - Soft tissue and bone lesions well demonstrated
58Shoulder Impingement - Instability
- Labral Pathology
- MRI with gadolinium - a must for labral pathology
- CT arthrography
59Shoulder Injury
- Scintigraphy
- Indications rare
- Screening
- Stress reaction of the bone
- Osteochondrosis Little League
Shoulder - Bone tumors
60Inservice Question - Shoulder
- A 70-year-old white female asks you to evaluate
her right shoulder because of pain and limited
motion. - Two months ago she remembers catching herself
while holding the refrigerator door handle when
she slipped on a wet floor. - She demonstrates pain and weakness at 45 of
abduction and weakness on external rotation.
She should be treated for A) Bicipital
tendinitis B) Disruption of the glenoid fossa
C) Rotator cuff tear D) Acromioclavicular
separation E) Incomplete fracture of the humeral
head
61Questions?
62Wrist Injury
63Wrist Injury
- Standard views PA and lateral
- PA view
- Constant 2 mm intercarpal
joint space - 3 arcs
- Lateral view
- 4 Cs
64Wrist Injury
65Scapholunate Dissociation
66Perilunate Injury
67Lunate Dislocation
68Radiography
- Complex Joints may require additional views
Anatomic Snuff Box Tenderness
Scaphoid Fracture
69Wrist Injury
- Scaphoid fracture
- Scaphoid view
- If negative, immobilization for 2 to 3 weeks,
followed by repeat films - If negative and symptomatic, limited MRI
70Chronic Wrist Pain
- Hamate Fracture
- CT scan
- Keinbocks Disease
- X-ray, bone scan, MRI
- Carpal Instability
- X-ray angles, MR
arthrogram
- TFCC Injury
- MR arthrogram
- Occult Ganglion
- MR arthrogram
- Complex Regional Pain Syndrome
- Bone scan delayed periarticular uptake
71Inservice Question - Wrist
- A 20-year-old white male presents to your office
after a fall on an outstretched hand while
skateboarding. - He has pain at the anatomic snuffbox with no
abrasion. - Radiographs are negative.
- Which one of the following would be the most
appropriate management? - A) A long arm cast for 8 weeks
- B) A thumb spica splint and follow-up radiographs
in 2 weeks - C) A sugar tong splint and follow-up radiographs
in 2 weeks - D) An Ace bandage and follow-up radiographs in 2
weeks - E) An Ace bandage and follow-up in 2 weeks if the
patient is still experiencing pain
72Questions?
73Hip Pain/Injury
- X-ray
- Good place to start
- Check for arthritis and avascular necrosis
- Can miss grade 4 cartilage damage
- May repeat hip x-rays early as one month as can
have significant interval degenerative change - Initial evaluation femoral neck for stress
fracture
74Hip Pain/Injury
- MRI
- Need strong magnet (1.5 tesla) and surface coil
- Bad for cartilage
- 42 false negative for cartilage damage, but may
show indirect findings - Good for diagnosis and localization of femoral
neck stress fractures
75Hip Pain/Injury
- MRA
- Good at finding labral pathology
- Increased sensitivity, but also
increased false positive - Sequence for gadolinium can
obscure bone pathology - Get ANESTHETIC injection with contrast!
- Relief of pain with intraarticular MRA anesthetic
may give more information than study
76Hip Pain/Injury
- Iliopsoas Bursography (Fluoscopic)
- Can diagnosis snapping hip caused by iliopsoas
tendon - flexion to extention reproduces
- Can be followed by therapeutic corticosteroid
injection of bursa - Can be difficult to visualize due to C-arm
getting in way of hip motion - Ultrasound
- Non-invasive, can compare sides
- Requires excellent technician and advanced
ultrasound machine
77Inservice Question - Hip
- A 19-year-old female runner has a 1-week history
of constant groin pain. - There is limited hip motion on flexion and
internal rotation of the right hip. - Radiographs of the hip and pelvis are normal.
- Which one of the following is the most likely
diagnosis? - A) Iliotibial band syndrome
- B) Stress fracture of the right femoral neck
- C) Osteitis pubis
- D) Pelvic inflammatory disease
78Questions?
79Knee Injury
80Acute Knee Trauma
81Acute Knee Trauma
- Value of cross table lateral
- Rule out fracture
- Can reveal fat-fluid level in joint
(lipohemarthrosis)
82Segond sign
Small lateral capsular bony avulsion lateral to
the tibia at the level of the joint
83Acute Knee Trauma
- Advanced imaging
- CT scan for complex fractures
- MRI for soft tissue
- MRI imaging modality of choice - T2 weighted
images - pathology sequence
84Chronic Knee Series
- X-rays
- Lateral
- Sunrise/Merchant
- PA/axial/tunnel
- AP weight bearing
85Chronic Pain/Instability
- X-ray
- 45o weight bearing flexion PA
- Weight bearing AP on long cassette
- MRI
- Meniscal injury
- Ligamentous insufficiency
- Osteochondral injury
86Questions?
87Leg Pain
- Exertional leg pain differential diagnosis
- Shin splints
- Stress fracture
- Exertional compartment syndrome
- Popiteal artery entrapment syndrome
88Exertional Leg Pain
- Shin Splints
- Clinical diagnosis
- Plain films to r/o stress fracture
- Triple Phase Bone Scan
- Phase
- Blood flow and Pool only classically no uptake
on delayed images. - Appearance
- Linear not fusiform
Arrows stress fracture Arrowheads periostitis
89Scintigraphy
- Triple phase bone scan
- Flow (perfusion) study
- 60 seconds after injection
- Blood flow
- Blood Pool
- Increased circulation, blood vessel dilation
- Delayed
- 2 -3 hrs after injection
- Bone uptake (clearance from extraosseous tissues)
90Stress (Overuse) Fractures
- Initial radiograph normal in up to 70 of
athletes at onset of pain - Fluffy, ill-defined sclerotic line perpendicular
to major trabecular lines
91Stress (Overuse) Fractures
- Thin incomplete lucent line
- May proceed to completion
- Periosteal reaction
92Imaging of Early Stress Fractures
- MRI and bone scan near 100 sensitivity
- MRI improved specificity
93Chronic Exertional Compartment Syndrome
- Triple phase bone scan and MRI have not been
shown to be reliable to date to replace clinical
judgement with compartment pressure testing. - Samuelson DR, Cram RL The three-phase bone scan
and exercise induced lower-leg pain the tibial
stress test. Clin Nucl Med 199621(2)89-93.
94Popliteal Artery Entrapment Syndrome
- MRA with and without plantarflexion
- Some experienced ultrasound technicians able to
examine - Angiography
95Questions?
96Ankle Injury
97Acute Ankle Trauma
- When do you x-ray?
- Ottawa Ankle Rules
Stiell IG, McKnight RD, Greenberg GH, McDowell
I, Nair RC, Wells GA, et al. Implementation of
the Ottawa ankle rules. JAMA 1994271827-32.
98Dont forget the foot films!
- AP, lateral and oblique
- Contralateral foot films
- Weight-bearing views
- On the lateral, metatarsal shaft and tarsal bone
align - On AP and obliques, the 2nd met medial border
and middle cuneiform align
99Chronic Ankle Pain
- Chronic ankle pain
- MRI is thought to be the imaging modality of
choice for ligamentous injuries - Impingement lesions, tendon problems,
osteochondral lesions - CT is good for ankle fractures/bony pathology
- Occult fractures
- Consider bone scan for diffuse non-specific pain
with F/U CT if needed for superior bone
resolution - Stress fractures
100Questions?
101Ultrasonography
102Ultrasonography
- Ultrasound uses high-frequency sound waves to
produce images. - Can define masses and localize foreign bodies.
- MSK use very popular in Europe and Australia.
103Ultrasonography - Tendons
- Tendon evaluation (Achilles, patellar, rotator
cuff)
Normal Achilles Tendon
- Normal tendon bright structure with
longitudinally oriented bundles
Chronic Tendonopathy
- Blurring, thickening, loss of normal
architecture
104Ultrasonography - Muscles
- Gastrocnemius with hematoma
-Torn rectus femoris muscle
- Dynamic evaluation of
- rectus femoris
- - Complete disruption of fibers
105Conclusions
- The initial imaging of choice
remains plain radiography. - CT is good for bone.
- MRI is good for soft tissue.
- Scintigraphy is good for finding a process with
metabolic activity, or determining metabolic
activity. - Ultrasound will (hopefully) increasingly be used
in musculoskeletal imaging as operator and
interpreter skills increase. - Advanced imaging selection is based upon your
history and physical, knowing your specialists
imaging preferences, and consultation with your
regional radiologist as needed.
106Thank You
Questions?