Thoracolumbar and Chest Imaging Flashcards
Thoracic spine pathology
- Osteoporosis/anterior compression fractures
- Scoliosis
- Scheuermann’s Disease
- Spinal tuberculosis (Pott’s Disease)
Lumbar spine pathology
- Spondylosis
- Spondylolisthesis
- Stenosis
- Intervertebral disk herniation: anterior, intravertebrally, posterior/posterolaterally
- Degenerative disc disease
Thoracic spine imaging choices
- Radiograph: initial study unless high risk trauma
- CT: initial study for high risk trauma; one scan = head CT, thoracic abdominal pelvic (TAP) for viscera, & all imaging of the spine can be derived from this initial data set
- MRI: spinal cord, ligaments, soft tissues, neurological deficits not explained by CT
Thoracic spine imaging indications
- Trauma
- Pain radiating along chest wall (suspect rib fracture)
- Decreased ROM
- Compression fractures
- Scoliosis evaluation
- Instability
- AP and lateral views are standard
- ACR appropriateness criteria (4 clinical conditions) and diagnostic imaging pathway (thoracolumbar spine trauma)
Appropriate imaging for identification of low bone density & Fx risk in asymptomatic patient
- DXA PA spine
- DXA proximal femur and femoral neck & total hip
- QCT spine
Appropriate imaging for follow-up patients demonstrated to have risk for Fx or low density
- DXA PA spine
- DXA proximal femur, femoral neck, and total hip
- QCT spine
Appropriate imaging for identify low BMD
- DXA PA spine
- DXA proximal femur, femoral neck, and total hip
Appropriate imaging for follow up to low BMD
- DXA PA spine
- DXA proximal femur, femoral neck, and total hi
Appropriate imaging for diagnosis in patients with advanced degenerative changes of the spine with or w/o scoliosis
- DXA proximal femur, femoral neck, and total hip
- QCT spine
Appropriate imaging for suspected Fx, incident or prevalent of a vertebral body based on clinical Hx, height loss, or patient treated with corticosteroids
- DXA VFA
- X-ray thoracic & lumbar spine
How to rotation identified in a standard AP thoracic spine view
- Identified by the rotation of a pedicle toward the midline or by the spinous process away from midline
- Mild rotation is not abnormal
What is the normal interpedicular distance in the thoracic spine
- 20 mm in the thoracic spine & is the transverse diameter of the spinal canal
Describe a thoracic spine swimmers lateral view imaging
- patients arm is placed overhead to remove superimposition of the arm
Describe the T-spine 3 column stability concept
- Spinal columns assist in determining stability of fractures
- 1 column disrupted = stable spine
- 2 columns disrupted = potentially unstable spine
- 3 columns disrupted = instability
When is the thoracic spine most injured
- Most injured with flexion forces
- Most common fracture location is T12/L1
Describe the anterior, middle, and posterior column of the T-spine
- Anterior column: anterior longitutidinal ligament, anterior annulus, and anterior 2/3 vertebral body
- Middle column: Posterior 1/3 of vertebral body, posterior annulus, posterior longitudinal ligament
- Posterior column: pedicle, facets, lamina, spinous process, and posterior ligaments
What are the big 3 signs of a compression fracture
- Step defect
- Wedge deformity
- Linear zone of impaction
What fracture comprise the majority of all vertebral fractures over the age of 60 years old
- Anterior compression fractures
Why are anterior compression fractures the most common
- Bone density make-up
- Anatomy: thoracic kyphosis
- Forces: axial loading results in flexion moment
- Fetal position for protection
How long does it take anterior compression fractures to heal
- ~3-6 months
- Wedge sign may persist after healing
- Younger patients will have bracing for 4-6 wks
Describe a seat belt/Chance fracture
- Fracture involves hyperflexion-distraction injury with compression of the anterior vertebral body & posterior ligament complex disruption
- MOI: spine is forcibly flexed over a horizontal restraint as is commonly seen in MVAs where seatbelts have been used
- Imaging: Radiographs will identify the Fx; CT will be used 1st to screen for significant injury via a TAP (thoracic-abdominal-pelvic) scan
What are the 4 common curve patterns seen in scoliosis
- Right thoracic
- Right thoracolumbar
- Left lumbar
- Double major right thoracic left lumbar
Radiography is critical in the management of scoliosis to determine etiology, demonstrate structural versus nonstructural curves, assess skeletal maturity, and monitor the effects treatment (True/False)
- True
Describe nonstructural scoliosis
- Not fixed and possibly amendable to bracing & physiotherapy
- Retains flexibility & will reverse or straighten on lateral flexion toward the convex side
- Can result form postural adaptations, nerve root irritation, inflammation, or leg length inequality
Describe Cobb angle
- Widely accepted radiographic measurement of scoliotic curves
- (1) Identify the uppermost involved vertebra of the curve
- (2) Identify the lowermost involved vertebra of the curve
- (3) Draw perpendicular lines through those 2 lines & measure the resulting intersecting angle
Scoliosis treatment
- <20º: no active treatment but close observation for month/years
- 20-40º: spinal bracing + exercise for several months/years until skeletal maturity
- > 50º: surgical fixation
MRI indications for thoracic spine imaging
- Degenerative disc disease (DDD)
- Extradural soft tissue/bony neoplasms
- Intramural masses
- Intramedullary tumors
- Treatment field for radiation
- Intrinsic spinal cord pathology (demyelinating, inflammatory, vascular)
- Syringohydromyelia
- Post-op intraspinal fluid/post-op changes
- Meningeal abnormalities
- Spinal infections
- Vertebroplasty; kyphoplasty
MRI interpretation (ABCDS)
- Alignment: sagittal slices best for assessing normal spinal alignment/deviations in alignment that signal Fx, dislocation, destruction of bone
- Bone signal: look for erosions signifying disease/infection, look for bone bruises on T2 weighted MRI
- Canal space/CNS: spinal canal space, look for effacement
- Disk integrity: disk height & hydration of NP, view posterior margins on sagittal view
- Soft tissues: paravertebral soft tissues, inspect integrity of ligaments & SC (spinal cord)
CT indications for thoracic spine imaging
- Trauma
- Degenerative conditions like OA
- Bone graft, instrumentation fusion, post operative
- Infectious processes of the spine
- Neoplastic conditions
- Inflammatory lesions
- Congenital/developmental spine abnormalities
- Spinal cord syringes, intrathecal masses
CT interpretation (ABCDS)
- Alignment: coronal reformats = AP view, sagittal reformats = lateral view
- Bone density: cortical bone most dense (post vertebral structures); cancellous bone less dense (vertebral bodies)
- Canal space: axial views for patency
- Disk integrity: posterior & psosterolateral margins on axial view for contour & intact borders
- Soft tissues
Describe Scheuermann’s Disease
- Occurs when the front portions of the upper part of spine does not develop as much as the back part of the spine giving the vertebra a wedge shape
- Adolescent boys/girls
- Backache, thoracic kyphosis
- Schmorl’s nodes
Describe Tuberculous osteomyelitis aka Pott’s Disease
- Occurs secondary to tuberculous
- Thoracic back pain
- Kyphosis
- Weight loss, fever, fatigue
- Infection progresses to several vertebra
Describe rib fractures
- Chest wall injury can range ins severity from minor bruising to an isolated rib fracture
- MOI: blunt trauma, in frail patients severe coughing can cause Fx, in infants/young children most rib Fx are suspicious of abuse
- Imaging: PA chest radiograph is the primary study
Lumbar spine imaging diagnostic approach
- Strong for: pts with LBP recommend HX and physical exam, that should include identifying & evaluating neurologic deficits, red flag sx, and phychosocial
- Weak for: pts with LBO suggest performing a mental health screening as part of the LBP evaluation & taking results into consideration during selection of tx
- Strong for: pts with LBP recommend diagnostic imaging & appropriate laboratory testing
- Strong against: pts with acute axial LBP recommend against routinely obtaining imaging studies or invasive diagnostic tests
- N/A: pts with LBP greater than 1 mo who have not improved or responded to initial Tx
Routine radiographic evaluation for lumbar spine
- 2-5 different projections
- AP = all 5 vertebra
- Lateral = alignment, disc spaces
- Lateral L5-S1 = lumbosacral junction view
- R and L obliques to observe facet joint articulations
Describe a normal AP view of the lumbar spine
- Facet joints are vertically orientated
- Spinous processes in midline
- Intervertebral spaces equal
- Pedicles are spaced equal distance from the spinous process
- Intervals between spinous processes are equal
Normal interpedicular distance in lumbar spine
- 25 mm in L1-L3
- 30 mm in L4-L5
- Misalignment in the relationship of these structures may indicate a fracture-dislocation
- Distance between pedicles represents the transverse diameter of the spinal canal
Describe the alignment of lumbar vertebrae in a lateral view
- Follows the same 3 column stability rule
- Disruption in these parallel lines may indicate fracture, dislocation, or spondylolisthesis
What does a standard lumbar oblique view show
- Shows facet joints and “scottie dog”
Radiologic findings of DDD
- Decreased disk space height
- Osteophytes at vertebral endplates
- Schmorl’s nodes
- Vacuum phenomenon
Radiologic findings of degenerative joint disease (DJD)
- Decreased zygapophyseal joint space
- Sclerosis
- Osteophytes at joint margins
Radiologic findings of Spondylosis
- Osteophytes visible as radio dense irregularities at vertebral joint margins
Radiologic findings of Spondylosis deformities
- Claw like spurs cupping toward intervertebral disk: present at more than one level but distinguished from DISH
Radiologic findings of Diffuse idiopathic skeletal hyperostosis (DISH)
- Flowing ossification of at least 4 contiguous vertebrae
- Preservation of disk height & absence of DDD findings
- Absence of sacroillitis or zygapophyseal joint DJD
Describe spondylosis scotty dog sign
- Spondylosis is diagnosed on the oblique radiograph as a radiolucent streak across the pars interarticularis (scotty dog)
- MOI: heavy mechanical loading in spinal extension; most often sports like weightlifting, trunk rotation sports like tennis
- Presentation: presents as non radiating unilateral LBP, pain reproduced with loading, 3-6 mod to heal, must stop loading the area
- Nonunion is common and can result in spondylolisthesis
What is a spot film
- A spot film may be used to focus on a segment(s) versus all 5 lumbar vertebrae
Grades of spondylolisthesis seen in a lateral view
- Grade 1: 25%
- Grade 2: 50%
- Grade 3: 75%
- Grade 4: 100%
Signs of degenerative changes in the lumbar spine
- Loss of disc space
- Hypertrophic spurs
- Disk calcification
- Herniated/protruding disks
Describe spinal stenosis
- Spinal stenosis is a narrowing of the spinal canal caused by degenerative joint & disk changes
- Classified into 3 anatomic regions: Stenosis of the central canal; Stenosis of the intervertebral foramen; and Stenosis of the lateral or subarticular recesses
- More than one region may be involved at the same intervertebral level
Features of neurogenic claudication
- Cramping pain
- LBP
- Sensory symptoms
- Muscle weakness
- Reflex changes
- Normal arterial pulses
- Aggravating factors: erect posture, ambulation, extension of spine
- Relieving factors: sitting, bending forward, squatting
- Walking uphill produce symptoms later
- Walking downhill produce symptoms earlier
- No symptoms in bicycle test unless erect
Features of vascular claudication
- Burning, cramping pain
- Decreased or absent arterial pulses
-Arterial bruits - Skin/dystrophic changes (eg cyanosis, hair loss)
-Aggravating factors: any leg exercise - Relieving factors: rest
- Walking uphill produce symptoms earlier
- Walking downhill produce symptoms later
- Bicycle test provokes smyptoms
Describe disk herniations
- Protrusion of nuclear disk material through the annulus fibrosus
- Spndylosos deformans: anterior disc herniation that disrupts all creating osteophyte formation at the anterior & lateral joint margins
- Schmorl’s nodes are caused by intervertebral herniation
- Infraspinal herniation = compressed neural elements
What imaging is least valuable and which is the most appropriate for evaluating disk herniations
- Conventional radiographs are of little value in the demonstration of intervertebral disk herniations
- MRI is most appropriate for evaluating disk herniations if a patient is a surgical candidate
- No imaging for 4-6 wks is appropriate for the clinical condition of low back and radicular pain with the exception of signs of cauda equina
Slide 55
Image
Most common to rare locations for disc herniation
- Commonest: subarticular
- Common: foramina or extraforaminal
- Rare: central
Describe degenerative disc disease (DDD)
- Decreased disk space height
- Spondylosis deformans
- Vacuum disc phenomenon
- Osteophyte formation
- Potential signs of instability
Describe ankylosing spondylitis
- Chronic, progressive, inflammatory arthritis characterized by joint sclerosis & ligamentous ossification
- Occurs in young adult males: about 20 yrs
- Often associated with ulcerative colitis
- Bamboo appearing spine caused by calcifications bridging over the disk spaces
Signs of spinal infection
- Destructive process that involved or crosses disk space
- Tumor will typically not involve the dis space
- MRI > CT scan
- Indicated: localized pain, elevated ESR and WBCs, fever, + blood culture
Signs of spinal neoplasms
- Commonly from metastatic disease from cancer elsewhere in the body
- Lytic lesions: lung, renal, breast cancer, multiple myeloma
- Sclerotic lesions: prostate and breast cancer
Indications for a bone scan (best option) for spinal neoplasms
- Initial staging of lung, breast, or prostate cancer
- Bone pain
- Elevated alkaline phosphate
- To elevate the response to chemotherapy
Describe the winking owl sign
- Indicates a destroyed pedicle due to spinal metastases, intraspinal malignancies, tuberculosis or other infection, congenital absence, neurofibromatosis, poor visualization or radiation therapy
Describe Schmorl’s nodes (seen on CT)
- Common spinal disc herniation in which the soft tissue of the intervertebral disc bulges out into the adjacent vertebrae through an endplate defect
- Commonly seen in the upper lumbar spine & are often discovered incidentally on imaging studies
Most common fractures of the lumbar spine (seen on CT)
- Wedge compression
- Compression burst fracture
- Spondylolysis
Indications for MRI of the spine
- DDD
- Soft tissue neoplasm/masses
- Meningeal anomalies
- Intrinsic spinal cord pathology
- Spinal vascular malformations
- Spinal infections
- Pre-operative assessment for vertebroplasty
Purpose of chest radiograph & cardiopulmonary imaging
- 1st imaging in cardiopulmonary assessment
- Separates cardiac from pulmonary disease
- Defines many conditions to initiate treatment
- Narrows the differential diagnoses to direct further imaging
Describe a routine chest radiograph & cardiopulmonary imaging
- 2 projections
- Posteroanterior (PA) view: lung fields, mediastinum (trachea, heart, great vessels, esophagus), and bony thorax
- Lateral: left side to demo the heart, left lung, retrosternal space, anterior/posterior mediastinum, and thoracic spine
ABC checklist for the chest radiograph (A-J)
- Airways
- Bones
- Cardiac contours
- Diaphragm
- Effusion
- Fields of the lungs
- Gastric bubble
- Hilum
- Inspiration
- Jazz, all that
ACR appropriateness criteria for rib fractures
- Adult <65 yrs: X-ray of the chest is usually appropriate (PA view)
- Adult >65 yrs: X-ray of the chest is usually appropriate (PA view)
Describe cardiothoracic ratio
- Estimate of heart size on the PA radiograph
- In adults the width of the heart should be less than half the width of the chest
Describe Silhouette sign
- Localize water based lesions to a specific lobe of the lung
- Refers to a loss of the normal heart or diaphragm border when a lesion is in a lobe adjacent to it
Describe the diaphragms location
- 10th pair of posterior ribs
- Can be elevated or flattened due to pathology
- R side is higher due to underlying liver, L side overlies the stomach
Classic characteristics of patients with chronic obstructive pulmonary disease (COPD) on a PA chest radiograph
- Abnormally flattened diaphragm
- Narrowed mediastinum
- Elongated lung fields
- Heart that appears to “swing” suspended over the diaphragm
Pathologies that can show up on chest radiographs/cardiopulmonary imaging
- Lung fields abnormally white = pneumonia, atelectasis, pleural effusion
- Lung fields abnormally black = pneumothorax, chronic obstructive pulmonary disease
- Mediastinum abnormally wide = aortic dissection, lymphadenopathy
- Heart abnormally shaped = congestive heart failure (CHF), mitral valve stenosis
Describe echocardiography
-Ultrasound study of the heart
- Assesses blood flow, cardiac output, ejection fraction, valve function, heart wall motion, pericardium
Describe ventilation/perfusion scans (V/Q)
- Use radioisotopes to evaluate flow of air and blood to all segments of the lungs
- “mismatch” of ventilation and perfusion = PE (pulmonary embolism)
Describe nuclear perfusion studies
- Use of a radioisotope to define perfusion of blood in the myocardium at rest & under stress
- Detects presence/severity of coronary artery disease
Describe multicoated acquisition scan (MUGA)
- Radioisotope to evaluate heart ventricles
- Evaluates ejection fraction
Describe angiography
- Study of blood flow in blood vessels
