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Common Sequences
and
Clinical Application in MSK‐MRI
Pramot Tanutit, MD.
Faculty of Medicine, Prince of Songkla University
Hat Yai, Songkhla, Thailand
April,25th 2019
Content
• Common MR‐sequences in MSK
• Imaging planes
• Imaging protocols in specific disease and organs
Common MR‐sequences in MSK
• T1W
• Anatomy
• Fat, subacute blood
• Bone marrow
• Tumor staging
• Gd
• Proteinaceous fluid
Common MR‐sequences in MSK
• T2W
• Anatomy
• Fluid
• Mass
• Cartilage
• Muscle
T2W‐Fat saturation
T2WI and T2W‐FS
• Non sensitive
• T2W‐non FS: miss some pathology
• T2W‐FS: increase sensitivity
• Very specific
• Assess: tendon, ligament, meniscus
• Pitfall: decreased fluid SI if there is hemorrhage (esp. 3T)
• Inhomogeneous fat suppression
STIR
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Common MR‐sequences in MSK
• Proton Density (PD) or intermediate weighted
• Anatomy
• Cartilage
• Labrum
• Ligament
• Tendon/muscle
• Fluid
PD‐Fat Saturation
PDW and PDW‐FS
• PDW‐FS: the most important sequence in MSK imaging
• Very sensitive to define pathology
• Except; sclerosis, fibrosis or fat accumulation‐pathology.
• Inhomogeneous fat suppression esp. in metallic implants due to frequency‐selective fat saturation
STIR
Common MR‐sequences in MSK
• Gradient echo (GRE)
• Blood
• Cartilage/Disc
• Calcification
• Susceptibility artifactsT2W
GRE
Gradient‐echo (GRE)
• Susceptible to artifact
• Easily imitate or miss pathology
• Evaluate cartilage thickness
• Calcification and hemorrhage
T2WT1W
GRE
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Common MR‐sequences in MSK
• Fluid sensitive sequences: T2W‐FS, PDW‐FS, IR.
STIR sequence
• Homogeneous fat suppression
• Fluid sensitive
• Lower resolution than PDW‐FS or T2W‐FS
Common MR‐sequences in MSK
• T1W vs PD
• T1‐SE showed bone marrow best but may isointense with marrow fat on PDW (obscured pathology)
• T1 showed anatomy well but menisci and labrum may be artificially bright due to magic angle effect.
• PD is better than T1 for menisci and tendon
Common MR‐sequences in MSK
Gadolinium administration
• Extension of disease
• Activity of disease
• Tumor vascularity
• Post operation: joints, spine
• Helping detection: small joints or small organs
• Alterative in large joints or large organs
Intravenous contrast administration:Necessary ?
• Detect inflammatory change esp. at the enthesis
• Estimate the extent of synovitis and soft tissue tumor extension
• Differentiate solid from cystic lesion
• Identify necrosis
• Identify scar formation
No Gd‐injection
• Patient deny• History of adverse effect
• Pregnancy • Poor renal function; low GFR (< 30)
•Will discuss in some case
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Pulse sequences
Artifact depends on Hardware Composition: susceptibility of metals
• Bad sequences: GRE, Fat‐saturation, (spin echo)
• Good sequences: FSE, IR
• Bad metals• Stainless steel: large artifacts, plates and screws• Cobalt chrome: moderate artifacts, older hip, bipolar hips and knees
• Good metals• Titanium:minimal artifacts. Newer hips, IM nail
• Oxidized Zirconium: oxinium, moderate artifact
Imaging planes
• Anatomical position:
• Scout images: landmarks
• Coronal‐Axial‐Transverse: foot, sacrum/ SI joints, hip
MRI Knee
• Flex knee about 10 degree
• Slightly external rotation
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MRI Knee: Coronal‐obliqueBlumensaat’s line
MRI Knee: Coronal‐oblique (inadequate)
MRI Ankle: Sagittal plane MRI Ankle: Coronal‐oblique
MRI Foot:
Axial,TransverseCoronal
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Sacrum and SI joints Elbow
WristHip
Marker
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MRI Protocol
• Depend on clinical question• Depend on institute
• Basic protocols• T1W, T2W non‐FS• Fluid sensitive sequences: T2W‐FS, PDW‐FS, STIR• GRE: tumor, hemorrhage, calcification
Gd‐injection?
Internal derangementTrauma or degeneration
Knee
• Sagittal: T1W, PDW‐FS.
• Coronal: PDW‐FS.
• Coronal‐oblique: PDW (parallel to ACL or PCL)
• Axial: T2W, PDW‐FS.
Sagittal PDW‐FSMarrow edema/bruise
Lipohemarthrosis
Grade2 chondral injury RADIAL MENISCAL TEAR
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JUMPER’S KNEEInternal derangementTrauma or degeneration
Hip
• Coronal: T1W, PDW‐FS, T2W.
• Transverse: T2W.
• Sagittal: PDW‐FS.
• Post Gd‐T1W‐FS in 3 planes.
AVN and Subchondral fractureInternal derangementTrauma or degeneration
Ankle
• Sagittal: T1W, PDW‐FS
• Axial: PDW‐FS, T2W
• Coronal: PDW‐FS
• Coronal‐oblique: PDW (parallel to calcaneus on Sagittal plane)
• Post Gd‐T1W‐FS in 3 planes
Technique • Coronal PD‐FS
• Sagittal T1W, PD‐FS
• Axial PD‐FS
• Note: avulsion fracture Lack of marrow edema : GRE (calcification sensitive) and thin slice T1W (SE, fat marrow evaluation)
• Transverse oblique; helpful in assessment of anterior tibiofibular and fibulocalcaneal ligaments.
Technique • Supine with neutral position; semidorsiflexion of foot.
• Prone position with plantar flexion• Decreased magic angle artifact
• Decreased motion artifact
• Helpful in diagnosis of Morton’s neuroma
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65 years‐old female Internal derangementTrauma or degeneration
Foot
• Prone position (prefer)
• Coronal (parallel to metatarsal bones): T1W, PDW‐FS.
• Transverse (short‐axis): T2W, PDW‐FS.
• Sagittal: PDW‐FS.
• Post Gd‐T1W‐FS in 3 planes.
Internal derangement: Shoulder
Position of shoulder and arm
Internal Rotation shoulder • Neutral to slightly external rotation
Imaging Planes: coronal
Imaging Planes:Sagittal Sequences: • Marrow and Muscle: T1W
• Detection: water sensitive sequences; STIR, T2W‐FS, PDW‐FS
• Characterization: T1W, T2W, GRE
• Routine PSU protocols:• Axial; PDW‐FS
• Coronal; T1W, PDW‐FS
• Sagittal; T2W
• Contrast injection: need
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Full thickness tear of supraspinatus tendon
Internal derangementTrauma or degeneration
Elbow
• Coronal T1W, PDW‐FS.
• Coronal‐oblique: PDW‐FS (collateral ligament)
• Sagittal PDW‐FS.
• Axial T2W, PDW‐FS.
• Post Gd‐T1W‐FS in 3 planes.
Internal derangementTrauma or degeneration
Wrist, Hand, Finger
• Coronal T1W, PDW‐FS.
• Axial T2W, PDW‐FS.
• Sagittal PDW‐FS.
• Post Gd‐T1W‐FS in 3 planes.
Sternum and sternoclavicular joint
Prefer prone position
• Coronal T1W, T2W, STIR.
• Axial T2W, PDW‐FS.
• Post Gd‐T1W‐FS in 3 planes.
Trauma: soft tissue, bone
• Coronal: T1W, STIR.
• Sagittal: T1W, STIR.
• Axial: T2W, PDW‐FS, GRE.
Depend on bone or organ
Tumor: soft tissue
• Axial T1W, T2W, GRE.
• Coronal T1W, PDW‐FS.
• Sagittal PDW‐FS.
• Post Gd‐T1W‐FS in 3 planes.
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38 years‐old female: myxoid liposarcoma
Tumor: bone
• Sagittal T1W, STIR (T2W‐FS or PDW‐FS).
• Coronal T1W, STIR (T2W‐FS o PDW‐FS).
• Axial T1W, T2W, GRE.
• Post Gd‐T1W‐FS in 3 planes.
• Included whole bone length and proximal joint
Arthritis
• Sagittal T1W, PDW‐FS (STIR).
• Coronal T1W, PDW‐FS (STIR).
• Axial T1W, T2W, GRE.
• Post Gd‐T1W‐FS in 3 planes.
Spine: trauma, degeneration
• C‐spine: Sagittal T1W, T2W, STIR. Axial T2W, 3DGRE (1.5 mm). Coronal T2W. MR‐myelography.
• Thoracic spine, TL‐spine, LS‐spine: • Sagittal T1W, T2W, STIR.
• Axial T2W.
• Coronal T2W.
• MR myelography.
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Spine: inflammation, infection, tumor
• Sagittal T1W, T2W, STIR.
• Axial T2W.
• Coronal T2W.
• Post Gd‐T1W‐FS in 3 planes.
Tbc spondylitis
Level labelling
Right renal artery levelL1/2 disc
Mid body
Screening or scout sagittal whole spine Iliolumbar ligament: L5 level
Sagittal planeshould cover costovertebral joint Conclusion
• Common MR‐sequences in MSK
• Imaging planes
• Imaging protocols in specific disease and organs
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Thank you for your attention
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