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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6009_Библиотеки_им_академика_М_И_Перельмана.pdf
(Left) Sagittal graphic shows
lumbar disc space infection
with vertebral body
osteomyelitis with endplate
destruction and marrow
edema. There are ventral and
dorsal abscess collections.
(Right) Sagittal T1WI C+ FS
MR in this case of disc space
infection shows enhancement
of L5 and S1 bodies ſt and an
intervertebral disc with
prevertebral and epidural
phlegmon extension.
Infection and Inflammatory Disorders
(Left) Axial T1WI C+ MR of a
disc space infection shows
inflammatory extension into
the prevertebral space, psoas
muscles, and dorsal spinal
muscles. Phlegmon extends
into the ventral epidural space
with thecal sac compression
ſt. (Right) Axial T2WI FS MR
shows inflammatory extension
into the prevertebral space,
psoas muscles ſt, and dorsal
spinal muscles .
Pathways of Spread
240
(Left) Axial T1WI C+ MR shows
disseminated
coccidioidomycosis with
diffuse bone and soft tissue
involvement and adjacent
paraspinal extension and
extension into lung. (Right)
Axial T2WI MR in
coccidioidomycosis shows
huge paraspinal abscesses ſt.
There is effacement of the
normal thecal sac within the
spinal canal due to disc space
infection and osteomyelitis.
Pathways of Spread
Infection and Inflammatory Disorders
(Left) Sagittal graphic shows
the dermal sinus ſt extending
from the skin surface to the
conus, with conus abscess
and extensive cord edema.
(Right) Sagittal T2WI MR in a
patient with a cervical cord
abscess and streptococcal
endocarditis shows diffuse
cord expansion with a ringshaped area of low T2 signal
(abscess capsule) within the
cord from C4 to C5-C6 ſt.
(Left) Sagittal T1WI C+ MR
with fat suppression shows
extensive subdural empyema
with peripheral enhancement
ſt throughout the cervical
spine and extending along
clivus . (Right) A septic
facet joint is shown. Axial
T1WI C+ MR at L4-L5 shows
extension of the infection to
the right facet joint with
diffuse facet bone
enhancement and juxta facet
soft tissue involvement .
(Left) Axial T1WI C+ MR shows
direct extension of infection
from a mycotic aortic
aneurysm ſt into the ventral
vertebral body, producing
bone destruction and
osteomyelitis . There is also
direct extension of infection
into psoas muscle st. (Right)
Axial CECT shows direct
extension of infection from a
mycotic aortic aneurysm ſt
into the vertebral body and
left psoas muscle st.
241
Pyogenic Osteomyelitis
KEY FACTS
TERMINOLOGY
• Definition: Bacterial suppurative infection of vertebrae and
intervertebral disc
• Synonyms: Pyogenic spondylodiscitis, disc space infection
IMAGING
• Ill-defined hypointense T1 vertebral marrow with loss of
endplate definition on both sides of disc
• Loss of disc height and abnormal disc signal
• Destruction of vertebral endplate cortex
• Vertebral collapse
• Paraspinal ± epidural infiltrative soft tissue ± loculated fluid
Infection and Inflammatory Disorders
collection
• Follow-up MR
○ Should focus on soft tissue findings
○ No single MR imaging parameter is associated with
clinical status
(Left) Sagittal T1WI MR in a
patient with a history of
lumbar surgery shows findings
of disc space infection at L4-L5
with hypointense marrow,
vertebral collapse, endplate
erosion, disc space loss, and
epidural phlegmon. (Right)
Sagittal T1WI C+ MR
demonstrates enhancing
vertebral bodies and
intervening disc. There is an
epidural abscess ſt extending
from L4-L5 to S1, consistent
with pyogenic vertebral
osteomyelitis. Severe central
canal narrowing is present at
L4-L5.
TOP DIFFERENTIAL DIAGNOSES
• Degenerative endplate changes
• Tuberculous vertebral osteomyelitis
• Spinal neuropathic arthropathy
PATHOLOGY
• Predisposing factors
○ Intravenous drug use
○ Immunocompromised state
○ Chronic medical illnesses (renal failure, cirrhosis, cancer,
diabetes)
• Staphylococcus aureus is most common pathogen
CLINICAL ISSUES
• Acute or chronic back pain
• Focal spinal tenderness
• Fever
• ↑ ESR, ↑ CRP, ↑ WBC
242
(Left) Sagittal STIR MR shows
increased fluid in the
retropharyngeal/prevertebral
space ſt. Marrow edema in C6
and C7 vertebral bodies is seen
st. There is fluid signal within
the disc space with irregularity
along the endplate cortical
margins. (Right) Sagittal T1WI
C+ FS MR shows
homogeneously enhancing
epidural phlegmon at the C6C7 level ſt causing mass
effect on the cord. C6 & C7
vertebral bodies exhibit avid
homogeneous enhancement
. Note the prevertebral,
enhancing soft tissues st
representing phlegmon.
Pyogenic Osteomyelitis
TERMINOLOGY
Synonyms
• Pyogenic spondylodiscitis, disc space infection
Definitions
• Bacterial suppurative infection of vertebrae and
intervertebral disc
IMAGING
General Features
• Best diagnostic clue
○ Ill-defined hypointense vertebral marrow on T1WI with
loss of endplate definition on both sides of disc
• Morphology
○ Loss of disc height, abnormal signal
○ Destruction of vertebral endplate cortex
○ Paraspinal ± epidural infiltrative soft tissue ± loculated
fluid collection
CT Findings
• NECT
○ Endplate osteolytic/osteosclerotic changes
○ Increase in paraspinal soft tissue
MR Findings
• Disc space
○ Hypointense on T1WI, hyperintense on T2WI
○ Diffuse or rim enhancement with gadolinium
• Vertebral marrow signal abnormality abutting disc
• Paraspinal and epidural phlegmon or abscess
• Cord compression
Nuclear Medicine Findings
• Bone scan
○ 3-phase technetium-99m diphosphonate scan shows
increased activity in all phases
• Gallium scan
○ Increased uptake of gallium citrate (Ga-67)
• WBC scan
○ Often false-negative in patients with chronic vertebral
osteomyelitis
Imaging Recommendations
• Best imaging tool
○ Sagittal and axial T2WI and T1WI MR
– Sensitivity (96%), specificity (92%), accuracy (94%)
○ SPECT Ga-67 scan good alternative
– Sensitivity and specificity in low 90%
DIFFERENTIAL DIAGNOSIS
Degenerative Endplate Changes
• Most common mimic
• Disc desiccation
• Vertebral endplates preserved
Tuberculous Vertebral Osteomyelitis
• Vertebral collapse, gibbus deformity
• Large dissecting paraspinal abscesses out of proportion to
vertebral involvement
Infection and Inflammatory Disorders
Spinal Neuropathic Arthropathy
• Sequela of spinal cord injury
• Disc space loss/T2 hyperintensity, endplate
erosion/sclerosis, osteophytosis, soft tissue mass
Chronic Hemodialysis Spondyloarthropathy
• Disc space loss, endplate erosion, vertebral destruction
Spinal Metastases
• Discrete or ill-defined vertebral lesions
○ Postgadolinium enhancement
• Disc space preserved
PATHOLOGY
General Features
• Etiology
○ Predisposing factors
– Intravenous drug use
– Immunocompromised state
– Chronic medical illnesses (renal failure, cirrhosis,
cancer, diabetes)
○ Staphylococcus aureus is most common pathogen
– Escherichia coli most common of gram-negative bacilli
– Salmonella common in patients with sickle cell disease
○ Bacteremia from extraspinal primary source
○ Direct inoculation from penetrating trauma, surgical
intervention, or diagnostic procedures
○ Extension from adjacent infection
– Diverticulitis, appendicitis, inflammatory bowl disease
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Back pain, tenderness, fever
• Other signs/symptoms
○ Myelopathy if cord compromised
○ Elevated erythrocyte sedimentation rate, C-reactive
protein, white cell count
Natural History & Prognosis
• Mortality rate: 2-12%
• Favorable outcome; resolution of symptoms if prompt
diagnosis & treatment
• Recurrence due to incomplete treatment (2-8%)
• Irreversible neurological deficits
○ Delay in diagnosis & neurologic impairment at diagnosis
significant predictors of neurologic deficit at follow-up
• Improvement in imaging findings may lag behind clinical
improvement
Treatment
• CT-guided or open biopsy yields causative organism > blood
cultures (77% vs. 58%)
○ Previous antibiotic treatment lowers yield (23% vs. 60%)
• Early empiric antibiotics, broad spectrum coverage until
causative pathogen isolated
• Spinal immobilization with bracing for 6-12 weeks
• Surgical treatment
○ Laminectomy, debridement, ± stabilization
○ Intervention if epidural abscess, instability present
243
(Left) Sagittal STIR MR
illustrates marrow edema
related to discitisosteomyelitis at the T12-L1
level . Intervertebral fluid
extends into the paraspinal
soft tissues . Cortical
irregularity along the adjacent
endplate margins is observed.
(Right) Sagittal T1WI C+ MR
shows peripheral
enhancement of the T12/L1
disc ſt and paraspinal
enhancing phlegmon st.
Infection and Inflammatory Disorders
Follow-up MR images often
depict less paraspinal
inflammation and less epidural
enhancement compared with
baseline images.
(Left) Sagittal STIR MR depicts
marrow edema in the L5 and
S1 vertebral bodies st. A
presacral fluid-intensity
collection ſt is observed. The
anterior cortical margin is
obscured. On follow-up MR
vertebral body disc space
enhancement and bone
marrow edema may be
equivocal or appear worse
compared with the baseline.
(Right) Axial CT reconstruction
exhibits an irregular cortical
break along the anterior
superior margin of the S1 body
ſt, subtle sclerosis , and a
presacral soft tissue
component st.
Pyogenic Osteomyelitis
244
(Left) Abnormal T1
hypointensity ſt is seen in the
marrow of 2 adjacent
midthoracic vertebral bodies.
Thin syndesmophytes st are
compatible with ankylosing
spondylitis (AS). (Right)
Sagittal T1 C+ MR shows
enhancement of the adjacent
irregular endplates st. Aseptic
spondylodiscitis can
complicate AS. Proliferative
epidural tissue without
inflammatory infiltrates and
new bone reaction, suggesting
the contribution of mechanical
factors, may cause
neurological complications.
Pyogenic Osteomyelitis
Infection and Inflammatory Disorders
(Left) Sagittal NECT (bone
window) of upper thoracic disc
space infection shows
destruction of the T1 and T2
bodies centered about the
collapsed disc space ſt with
marked endplate irregularity
and kyphotic deformity.
(Right) Axial NECT shows
destruction of the T1 and T2
bodies with marked endplate
irregularity ſt and a large
ventral paravertebral soft
tissue mass (abscess) .
(Left) Sagittal C+ MR shows
multiple compartments
involved by infection with
destruction and collapse of
the adjacent vertebral
endplates ſt, a large ventral
abscess st, and extension to
involve the posterior elements
. (Right) Sagittal STIR MR
shows T1 and T2 collapse with
endplate destruction and a
large ventral abscess that
displaces the anterior
longitudinal ligament ſt.
There is extension that
involves the posterior
elements st.
(Left) Sagittal T2 MR shows
C5-C6 disc space infection ſt
with increased signal from the
contiguous bodies and
extensive prevertebral edema
. There is a small epidural
abscess that mildly effaces the
cord st. (Right) Sagittal T1 C+
MR shows enhancement of the
C5 and C6 bodies with mild
disc irregularity and diffuse
prevertebral soft tissue
enhancement ſt. A small
ventral epidural abscess is also
present .
245
Tuberculous Osteomyelitis
KEY FACTS
TERMINOLOGY
• Tuberculous spondylitis (TS)
• Granulomatous infection of spine and adjacent soft tissue
secondary to tuberculosis
IMAGING
• Gibbus vertebrae with relatively intact intervertebral discs,
large paraspinal abscesses
• Midthoracic or thoracolumbar > lumbar, cervical
• Isolated posterior element involvement possible
• Sagittal STIR or FSE T2 with fat saturation most sensitive for
bone marrow edema, epidural involvement
Infection and Inflammatory Disorders
○ MR best modality to evaluate extent of disease, assess
response to treatment
TOP DIFFERENTIAL DIAGNOSES
• Pyogenic spondylitis
○ Initial infection in subchondral bone
○ Intervertebral discs typically affected
(Left) Sagittal graphic through
the lumbar spine depicts
multifocal granulomatous
osteomyelitis. Frank abscesses
are present at the L3-L4 disc
space ſt and between the
spinous process of L2 and L3
st. (Right) Sagittal STIR MR in
a patient with tuberculosis
(TB) infection shows
involvement of contiguous
vertebral bodies with
subligamentous abscess
spread and partial disc
involvement ſt. Multiple focal
bone lesions are present
without adjacent disc
involvement .
• Fungal spondylitis
• Spinal metastases
○ Extraosseous epidural or paraspinal extension
○ Disc space preserved
• Brucellar spondylitis
PATHOLOGY
• Hematogenous or lymphatic spread
• Initial inoculum in anterior vertebral body
• Spread to noncontiguous vertebral bodies beneath
longitudinal ligaments
CLINICAL ISSUES
• Chronic back pain, focal tenderness, fever
• Neurologic deficits more common with TS than other
granulomatous infections
• Concomitant pulmonary tuberculosis in ~ 10% of patients
• Spinal tuberculosis accounts for 2% of all tuberculosis cases
246
(Left) Sagittal T1WI C+ FS MR
demonstrates focal kyphosis
at L2-L3, collapse of the disc
space, avid vertebral body
enhancement ſt, and ventral
and dorsal paravertebral
abscesses st. There are
peripherally enhancing
abscesses in the paraspinal
soft tissues , which exhibit
hypointense rims . (Right)
Coronal T1WI C+ FS MR shows
TB osteomyelitis with L2
vertebra plana . Psoas
involvement with swelling and
marked enhancement ſt is
present. Inflammatory soft
tissue surrounds the disc .
Fungal and Miscellaneous Osteomyelitis
KEY FACTS
Infection and Inflammatory Disorders
TERMINOLOGY
• Noncaseating, acid-fast negative or fungal infections
primarily occurring as opportunistic infection in
immunocompromised patient
• Involvement of spine and adjacent soft tissue typically
secondary to fungal pathogen
IMAGING
• Osseous destruction ± disc, epidural, or paraspinal
involvement
○ Mixed lytic and sclerotic foci within vertebral bodies
○ Marrow edema
○ ± paravertebral mass, epidural phlegmon
• Diffuse > focal, lobulated contours
• May produce spinal deformity
TOP DIFFERENTIAL DIAGNOSES
• Pyogenic osteomyelitis
• Granulomatous osteomyelitis
○ Tuberculosis
○ Brucellosis
PATHOLOGY
• Hematogenous spread
• Direct extension from adjacent tissues
○ Direct implantation from trauma, hematogenous, local
extension, iatrogenic after lumbar puncture,
nucleoplasty
CLINICAL ISSUES
• Neck pain or back pain
• Clinical signs of systemic illness
• Risk factors: Immunosuppression, diabetes, hemodialysis,
corticosteroid use, chemotherapy, or malnutrition
DIAGNOSTIC CHECKLIST
• Also consider fungal entities when tuberculosis is in
imaging differential diagnosis list
(Left) Sagittal STIR MR
(coccidioidomycosis) shows
destruction and abnormal
signal involving multiple
vertebral bodies at the
thoracolumbar junction ſt.
There is severe compression of
the thecal sac. Note the
anterior extension underneath
the anterior longitudinal
ligament . (Right) Sagittal
T1 C+ MR (coccidioidomycosis)
shows extensive, multiple
vertebral body irregular
enhancement and destruction
ſt with dorsal and ventral
epidural extension and thecal
sac compression .
(Left) Sagittal T1 C+ MR
(coccidioidomycosis) shows a
rim-enhancing prevertebral
abscess st due to chronic
infection. There is destruction
of C7 and T1 vertebral bodies
ſt, relative sparing of the
intervertebral discs, and
ventral epidural phlegmon .
(Right) Axial T2WI MR
(blastomycosis) illustrates
hyperintense paraspinal
phlegmon st. A ventral
epidural mass mildly
displaces the cord without
cord signal abnormality.
247
Osteomyelitis, C1-C2
KEY FACTS
TERMINOLOGY
• Infection of C1-C2 articulation (pyogenic or tuberculous)
IMAGING
• Soft tissue mass within prevertebral space centered at C1C2
○ Prevertebral increased soft tissue/edema
○ Variable extension into epidural space, dural sac, or cord
compression
○ Low T1 signal, increased T2/STIR signal from vertebral
bodies, soft tissue mass
• ± bone destruction involving anterior arch of C1, odontoid,
Infection and Inflammatory Disorders
and body of C2
• Diffuse enhancement of vertebral bodies, soft tissue mass
within prevertebral region/epidural space
○ May show nonenhancing abscess focus
• MRA/CTA: Evaluation of skull base, C1-C2 instability with
vertebral artery compromise
(Left) Sagittal graphic
illustrates osteomyelitis
involving the odontoid with
bone destruction, extension to
the anterior arch of C1, and
formation of epidural abscess
ſt. (Right) Sagittal STIR MR in
this patient with a septic C1C2 joint shows extensive
abnormal signal from the
odontoid and C2 body with
phlegmon extension into the
prevertebral soft tissues ſt.
TOP DIFFERENTIAL DIAGNOSES
• Rheumatoid arthritis
• Odontoid fracture
• C1-C2 osteoarthritis
• Primary bone tumor/metastases
PATHOLOGY
• Hematogenous seeding to capillary ends/end arterioles in
subchondral regions
CLINICAL ISSUES
• Neck pain, limited range of motion, dysphagia
• C1-C2 subluxation, medulla compression, and
motor/sensory deficit
• Vertebral artery compression with posterior circulation
infarction
DIAGNOSTIC CHECKLIST
• Severe C1-C2 subluxation ± epidural phlegmon/abscess
248
(Left) Axial T1 C+ MR shows a
large amount of enhancing
phlegmon within the
prevertebral soft tissues ſt
with scattered smaller
nonenhancing abscesses .
(Right) Sagittal T1 C+ MR
shows an irregular area of
decreased enhancement in the
odontoid that is consistent
with bone infarction . There
is extensive prevertebral
enhancing phlegmon ſt. A
small amount of epidural
phlegmon is also present st.
Septic Facet Joint Arthritis
KEY FACTS
Infection and Inflammatory Disorders
TERMINOLOGY
• Suppurative bacterial infection of facet joint, adjacent soft
tissue
IMAGING
• Abnormal enhancement within facet joint with associated
facet marrow, adjacent soft tissue edema
○ Typically single level, unilateral involvement
○ Facet joint widening
○ Ill-defined facet marrow signal alteration
○ Eroded facet cortex
• Lumbar spine most common
• Protocol advice
○ Sagittal STIR or FSE T2 with fat saturation most sensitive
for bone marrow edema and epidural involvement
○ Postgadolinium T1WI with fat saturation better
delineates extent of facet, epidural, and paraspinal
involvement
TOP DIFFERENTIAL DIAGNOSES
• Facet joint osteoarthritis
○ Bilateral joint space narrowing with vacuum
phenomenon
• Facet synovial cyst
○ Juxtaarticular thin-walled, well-defined mass
• Rheumatoid arthritis
○ Widened facets with enhancing synovium
○ Facet joint erosion
PATHOLOGY
• Most common cause: Hematogenous contamination
○ Staphylococcus aureus in 86%; Streptococcus in 9%
• Direct inoculation from penetrating trauma, surgical
intervention, or diagnostic procedures
• Extension from adjacent infection in paraspinal soft tissues
○ Associated findings
– Spondylodiscitis
– Epidural paravertebral abscess
(Left) Axial graphic at a
lumbar vertebral level
demonstrates a septic right
facet joint with adjacent
osteomyelitis and abscess
extending into subarticular
recess st and posterior
paraspinal muscle ſt. (Right)
Axial T2WI MR with fat
suppression through lumbar
vertebra shows fluid in the left
facet joint ſt with posterior
extension and loculation.
Edema is present in
surrounding soft tissue .
(Left) Sagittal STIR MR shows
multilevel discitisosteomyelitis ſt with
interdiscal fluid and adjacent
endplate erosive changes.
There is also infection of the
facet joints of 2 adjacent
levels. Fluid is seen within the
facet joints st. There is
marrow edema of the articular
pillars as well as the
surrounding soft tissues .
(Right) Sagittal T1WI C+ FS
MR depicts the peri facet
inflammation associated with
septic facet arthritis st.
Epidural phlegmon extends
into the neural foramen ſt.
249