Pitfalls in Musculoskeletal Radiology 1st edition by Wilfred Peh 9783319534961 3319534963

Part I: Imaging Modality and Technique Pitfalls Related to the Musculoskeletal System

1: Radiography Limitations and Pitfalls

1.1 Introduction

1.2 Pitfalls Related to Radiographic Image Acquisition

1.2.1 Adequacy of Coverage and Views

1.2.2 Radiographic Technique and Positioning

1.2.3 Radiographic Artifacts

1.3 Limitations of Radiographic Imaging of Non-osseous Structures

1.3.1 Intra- and Periarticular Structures

1.3.1.1 Articular Cartilage

1.3.1.2 Synovium and Joint Fluid

1.3.1.3 Ligaments, Tendons, and Other Fibrocartilaginous Structures

1.3.2 Other Soft Tissues and Foreign Bodies

1.4 Radiographically Occult Osseous Abnormalities

1.4.1 Destructive Osseous Lesions

1.4.2 Trauma-Related Osseous Injuries

1.4.2.1 Undisplaced Fractures

1.4.2.2 Stress Injuries

1.4.3 Osteoporosis

References

2: Ultrasound Imaging Artifacts

2.1 Introduction

2.2 Ultrasound Imaging

2.2.1 Equipment

2.2.2 Physics

2.2.3 Doppler US

2.2.4 Normal Structures

2.3 Gray-Scale Artifacts

2.3.1 Beam Characteristics

2.3.2 Velocity Errors

2.3.3 Attenuation Errors

2.3.4 Multiple Echoes

2.4 Color and Power Doppler Artifacts

References

3: Computed Tomography Artifacts

3.1 Introduction

3.2 Physics-Related Artifacts

3.2.1 Noise

3.2.2 Beam Hardening

3.2.3 Scatter

3.2.4 Partial Volume Effect

3.2.5 Photon Starvation

3.2.6 Undersampling

3.3 Conventional Multidetector CT Scanner Artifacts

3.3.1 Ring, Windmill, and Cone Beam Artifacts

3.3.2 Stair Step and Zebra Artifacts

3.4 Metal-Related Artifacts

3.4.1 Causes of Metal-Related Artifacts

3.4.2 Solutions for Metal-Related Artifacts

3.4.3 Pitfalls of Metal Artifact Reduction

3.5 Patient-Related Artifacts

3.5.1 Patient Motion

3.5.2 Patient Positioning

3.5.3 Contrast-Related Artifacts

3.6 Dual-Energy CT Scanner Artifacts

3.6.1 Benefits of Dual-Energy CT

3.6.2 Pitfalls of Dual-Energy CT

3.7 Dedicated Extremity Cone Beam CT Artifacts

3.7.1 Benefits of Dedicated Extremity Cone Beam CT

3.7.2 Pitfalls of Dedicated Extremity Cone Beam CT

3.8 Dynamic Four-Dimensional Musculoskeletal CT Artifacts

References

4: Magnetic Resonance Imaging Artifacts

4.1 Introduction

4.2 MRI Artifacts

4.2.1 Motion

4.2.2 Susceptibility and Artifacts Related to Orthopedic Hardware

4.2.3 Chemical Shift

4.2.4 Magic Angle Phenomenon

4.2.5 Protocol Errors

4.2.5.1 Partial Volume Averaging

4.2.5.2 Radiofrequency Interference

4.2.5.3 Saturation

4.2.5.4 Shading

4.2.5.5 Truncation

4.2.5.6 Wraparound

4.3 Technical Pros and Cons

4.3.1 Fat-Suppression Techniques

4.3.2 Isotropic Imaging

References

5: Nuclear Medicine Imaging Artifacts

5.1 Introduction

5.2 Types of Artifacts

5.2.1 Radiopharmaceutical Related

5.2.1.1 Preparation and Formulation

5.2.1.2 Administration Techniques and Procedures

5.2.1.3 Pathophysiological and Biochemical Changes

5.2.1.4 Medical Procedures

5.2.1.5 Drug Therapy and Interaction

5.2.2 Instrumentation Related

5.2.2.1 Uniformity

5.2.2.2 Resolution and Linearity

5.2.2.3 Multiple-Window Spatial Recognition

5.2.2.4 Collimators

5.2.2.5 Field of View

5.2.2.6 Computer Related

5.2.3 Patient Related

5.2.3.1 Attenuation Artifacts

5.2.3.2 Multiple Radionuclides and Study Timing

5.2.3.3 Contamination

5.2.3.4 Patient Motion and Positioning Artifacts

5.2.3.5 Extraosseous Uptake

5.3 SPECT/CT-Specific Artifacts

5.3.1 SPECT Causes

5.3.1.1 Rotational: Uniformity and Center of Rotation

5.3.1.2 Alignment: Collimator, Gantry, and Gamma Camera

5.3.2 CT Causes

5.3.2.1 Misregistration Artifacts

5.3.2.2 Attenuation Errors

5.4 PET/CT-Specific Artifacts

5.5 DXA-Specific Artifacts

References

6: Arthrographic Technique Pitfalls

6.1 Introduction

6.2 General Considerations and Pitfalls

6.2.1 Communication and Consent

6.2.2 Anticoagulation

6.2.3 Infection

6.2.4 Adverse Reactions and/or Allergies

6.2.5 Pre-procedural Scan

6.3 General Concepts of Periprocedural Arthrographic Technique Pitfalls

6.3.1 Patient Positioning

6.3.2 Joint Line Versus Articular Surface

6.3.3 Needle Selection and Bevel Positioning

6.3.4 Contrast Agent and Mixture

6.3.5 Inadvertent Air Instillation

6.3.6 Joint Fluid

6.3.7 Joint Distension and Manipulation

6.3.8 Logistical Issues

6.3.9 Ultrasound Imaging Guidance

6.4 Joint-Specific Considerations and Pitfalls

6.4.1 Shoulder

6.4.1.1 Anterior Approach

6.4.1.2 Posterior Approach

6.4.2 Elbow

6.4.3 Wrist

6.4.4 Hip

6.4.5 Knee

6.4.6 Ankle

References

7: Ultrasound-Guided Musculoskeletal Interventional Techniques Pitfalls

7.1 Introduction

7.2 Screening for Contraindications/Consent

7.2.1 Review of Request Form

7.2.2 Contraindications to Injection

7.2.3 Diagnostic Ultrasound Scan

7.2.4 Consent

7.2.5 Pre-procedural Check

7.3 Equipment Selection

7.3.1 Probe Selection

7.3.2 Syringe Selection

7.3.3 Needle Selection

7.4 Needle/Probe Technique

7.4.1 Triangulation

7.4.2 In and Out of Plane Needle Approaches

7.4.3 Needle Bevel Orientation

7.4.4 Needle-Beam Angle

7.4.5 Increasing Conspicuity of Needle Using US Machine Settings

7.4.6 Expulsion of Gas Within Needle

7.4.7 Injection of Local Anesthetic/Normal Saline

7.5 Specific Therapeutic Interventional Techniques

7.5.1 Local Anesthetic Injection

7.5.2 Corticosteroid Injection

7.5.3 Viscosupplementation

7.5.4 Dry Needling

7.5.5 Platelet-Rich Plasma (PRP) Injection

7.5.6 Management of Achilles/Patellar Tendinopathy

7.6 Post-procedure

References

8: Musculoskeletal Interventional Techniques Pitfalls

8.1 Introduction

8.2 Vertebroplasty and Bone Augmentation

8.2.1 Variant Anatomy

8.2.2 Altered Anatomy

8.2.3 Suboptimal Views

8.2.4 Needle Malpositioning

8.2.5 Cement Placement

8.2.6 Equipment Choice

8.3 Fluoroscopically-Guided Injections

8.3.1 Recognizing Different Sides of a Joint/Foramen

8.3.2 Sensitive Periosteum

8.3.3 Segmentation Anomaly During Spinal Injections

8.4 CT-Guided Bone Tumor Ablation

8.4.1 Slice Thickness

8.4.2 Limited Scan Range

8.4.3 Needle Retraction During Cryoablation

8.4.4 Thermal Ablation Zone Boundaries

References

9: Musculoskeletal Biopsy Pitfalls

9.1 Introduction

9.2 History of Musculoskeletal Biopsy

9.2.1 Early Studies Documenting Biopsy Complications

9.2.2 Recent Studies Documenting Biopsy Complications

9.3 Fundamental Biopsy Concepts

9.3.1 Before the Biopsy

9.3.1.1 Surgeon or Clinician

9.3.1.2 Pathologist

9.3.1.3 Patient

9.3.1.4 Imaging Review

9.3.1.5 Biopsy Needle Selection

9.3.1.6 Special Considerations

Densely Sclerotic Lesions

Cystic Bone Lesions

“Thin” Bone Lesions

9.3.2 During the Biopsy

9.3.2.1 Sample Site

9.3.2.2 Unanticipated Findings

Fluid

Just Blood!

Mucus

9.3.2.3 Imaging “Transverse Incision”

9.3.2.4 Imaging Documentation

9.3.2.5 Ending the Procedure

9.3.3 After the Biopsy

9.4 Helpful Hints

References

10: Errors in Radiology

10.1 Introduction

10.2 Prevalence

10.3 Mechanisms of Visual Perception

10.4 Errors in Perception

10.5 External Influences

10.5.1 Fatigue

10.5.2 Priming

10.5.3 Strain

10.5.4 Willpower

References

Part II: Regional and Disease-Based Imaging Pitfalls

11: Radiographic Normal Variants

11.1 Introduction

11.1.1 Identifying a Normal Variant

11.2 Types of Normal Variants

11.2.1 Pseudo-Variants

11.2.1.1 Spinal

11.2.1.2 Non-spinal

11.2.2 Anatomical Variants

11.2.2.1 Spinal

11.2.2.2 Non-spinal

11.2.3 Developmental Variants

11.2.3.1 Spinal

11.2.3.2 Non-spinal

11.2.4 Acquired Variants

11.2.4.1 Spinal

11.2.4.2 Non-spinal

11.3 Painful Variants

11.3.1 Spinal

11.3.2 Non-spinal

11.4 Variant or Pathology?

References

12: Long Bone Trauma: Radiographic Pitfalls

12.1 Introduction

12.2 General Considerations

12.2.1 Errors in Perception and Interpretation

12.2.2 Satisfaction of Search

12.2.3 Availability of Clinical Information

12.3 Practical Approaches for Combating Errors

12.4 Radiographic Signs

12.4.1 Atypical Radiographic Signs

12.4.2 Avulsion Fractures

12.4.3 Stress Fractures

12.4.4 Abnormal Underlying Bone

12.5 Shoulder Trauma

12.5.1 Radiographic Examination

12.5.2 Commonly Missed Injuries

12.5.2.1 Posterior Dislocation

12.5.2.2 Anterior Dislocation

12.5.2.3 Proximal Humeral/Greater Tuberosity Fractures

12.5.2.4 Acromioclavicular Joint

12.5.2.5 Scapular Fractures

12.5.2.6 Coracoid Process Fractures

12.5.2.7 Sternoclavicular Joint

12.6 Elbow Trauma

12.6.1 Non-displaced Radial Head Fractures

12.6.2 Coronoid Process Fractures

12.7 Wrist and Hand Trauma

12.7.1 Distal Radial Fractures

12.7.2 Scaphoid Fractures

12.7.3 Avulsion Fractures

12.7.4 Triquetral Fractures

12.7.5 Disorders of Alignment in the Wrist and Carpus

12.7.6 Carpal Instability

12.7.7 Lunate and Perilunate Injuries

12.8 Finger Trauma

12.9 Pelvic Trauma

12.10 Hip and Femoral Neck Trauma

12.11 Knee Trauma

12.11.1 Avulsions Related to the Distal Femur

12.11.2 Segond Fracture

12.11.3 Arcuate Complex Avulsion Fracture

12.11.4 Patellar Avulsion Fractures

12.11.5 Osteochondral Impaction Fracture

12.11.6 Stress Fractures

12.11.7 Soft Tissues

12.11.8 Tibial Plateau Fractures

12.12 Ankle Trauma

12.12.1 Soft Tissue Signs

12.12.2 Talar and Peritalar Fractures

12.12.3 Anterior Process of Calcaneus Fractures

12.12.4 Lateral Process of Talus Fractures

12.12.5 Posterior Talar Process Fractures

12.12.6 Talar Neck Fractures

12.12.7 Osteochondral Injuries

12.12.8 Dislocations

12.13 Foot Trauma

12.13.1 Base of Fifth Metatarsal Fractures

12.13.2 Lisfranc/Chopart Injury

12.13.3 Stress Fractures

12.13.4 Calcaneal Fractures

12.13.5 Hallux Sesamoid Bones

References

13: Spine Trauma: Radiographic and CT Pitfalls

13.1 Introduction

13.2 Pitfalls Due to Technical Factors

13.2.1 Radiography

13.2.2 CT

13.3 Pitfalls Due to Overlapping Tissues and Artifacts

13.3.1 Radiography

13.3.2 CT

13.4 Pitfalls Due to Normal Ossification and Developmental Appearances

13.4.1 Normal Ossification

13.4.2 Ossicles

13.4.3 Synchondroses

13.4.4 Vertebral Morphology/Shape

13.4.5 Pseudo-Subluxation

13.5 Pitfalls Due to Abnormal Development/Normal Variants

13.5.1 Segmentation Anomalies

13.5.2 Fusion Defects

13.5.3 Vertebral Transition

13.5.4 Scoliosis

13.6 Pitfalls Due to Acquired Disease

References

14: Spine Trauma: MRI Pitfalls

14.1 Introduction

14.2 Fracture Mimics

14.2.1 Normal Anterior Wedging

14.2.2 Limbus Vertebra

14.2.3 Congenital Anomalies

14.2.3.1 Congenital Basilar Impression

14.2.3.2 C2 and Os Odontoideum

14.2.3.3 Congenital Ligamentous Laxity

14.2.4 Segmentation Anomalies

14.3 Acute Compression Fracture: Benign Versus Malignant

References

15: Shoulder Injury: MRI Pitfalls

15.1 Introduction

15.2 Normal Anatomic Structures That May Mimic Pathology

15.2.1 Labrum

15.2.2 Cartilage

15.2.3 Ligaments

15.2.4 Osseous Structures

15.2.5 Rotator Cuff, Rotator Cable, and Rotator Interval

15.3 Postoperative Findings

15.4 Pitfalls Due to Imaging Techniques

References

16: Shoulder Injury: US Pitfalls

16.1 Introduction

16.2 Normal Anatomy and Physiology

16.2.1 Normal Tendon

16.2.2 Musculotendinous Junction and Tendinous Attachment

16.2.3 Rotator Interval

16.2.4 Deltoid Muscle

16.3 Technical Factors

16.3.1 Transducers

16.3.2 Focus

16.3.3 Anisotropy

16.4 Scanning Technique

16.4.1 Scrupulous Technique

16.4.2 Complete Rotator Cuff Evaluation

16.4.3 Dynamic Examination

16.4.4 Transducer Handling and Doppler Imaging

16.5 Patient Factors

16.5.1 Limitation of Movement

16.5.2 Obesity and Muscularity

16.6 Full-Thickness Tendon Tears

16.6.1 Small Full-Thickness Tears

16.6.2 Nonvisualization of the Rotator Cuff

16.7 Partial-Thickness Tendon Tears

16.7.1 Partial-Thickness Tears

16.7.2 Tendon Thinning

16.7.3 Tendinosis

16.8 Calcific Tendinosis

16.9 Trauma

16.9.1 Fractures

16.9.2 Hemorrhage and Edema

16.10 Other Related Lesions

16.10.1 Bursal Effusion

16.10.2 Osteoarthritis

16.10.3 Synovitis

16.10.4 Postoperative Shoulder

References

17: Elbow Injury: MRI Pitfalls

17.1 Introduction

17.2 Pitfalls from MRI Technique and Patient Positioning

17.2.1 Sequences and Positioning

17.2.2 Magic Angle Phenomenon

17.2.3 Arthrography

17.2.3.1 Indications for Arthrography

17.2.3.2 Arthrogram Technique and Protocol

17.2.3.3 Pitfalls Associated with Arthrography

17.3 Pitfalls in Normal Anatomy

17.3.1 Capitellar Pseudo-Defect

17.3.2 Pseudo-Lesions of the Trochlear Notch

17.3.3 Synovial Folds

17.3.4 Elbow Fat Pads

17.3.5 Triceps Insertion

17.3.6 Ulnar Collateral Ligament

17.3.7 Lateral Collateral Ligaments

17.4 Pitfalls in Normal Variant Anatomy

17.4.1 Distal Biceps Insertion

17.4.2 Bicipitoradial Bursa

17.4.3 Anconeus Epitrochlearis

17.4.4 Cubital Tunnel and the Ulnar Nerve

17.4.5 Red Marrow

17.4.6 Supracondylar Process

References

18: Elbow Injury: US Pitfalls

18.1 Introduction

18.2 Technique-Specific Pitfalls

18.2.1 Equipment/Transducer Selection

18.2.2 Operator Training

18.2.3 Anisotropy

18.2.4 Transducer Pressure

18.2.5 Dynamic Imaging

18.3 Diagnostic-Specific Pitfalls: Normal Variants

18.4 Diagnostic-Specific Pitfalls: Pathological Misinterpretations

18.4.1 Triceps Tendon Injury

18.4.2 Cubital Tunnel Syndrome

18.4.3 Elbow Snapping Syndrome

18.4.4 Acute Elbow Trauma

18.4.5 Elbow Plica Syndrome

18.4.6 Elbow Soft Tissue Masses

18.4.7 Medial or Lateral Epicondylar Pain

18.4.8 Medial Collateral Ligament Injury

18.4.9 Anterior Elbow Pain

References

19: Wrist and Hand Injuries: MRI Pitfalls

19.1 Introduction

19.2 Technical Factors

19.2.1 Magic Angle Phenomenon

19.2.2 Chemical Shift Artifacts

19.2.3 Susceptibility Artifacts

19.2.4 Motion Artifacts

19.2.5 Wraparound Artifacts

19.2.6 Partial Volume Averaging Artifacts

19.2.7 Saturation Artifacts

19.2.8 Truncation Artifacts

19.2.9 Shading Artifacts

19.2.10 Radio-Frequency Interference Artifacts/Zipper Artifacts

19.3 Osseous Injuries

19.3.1 Carpal Fractures

19.3.2 Marrow Edema

19.3.3 Scaphoid Fractures

19.3.4 Scaphoid Osteonecrosis

19.3.5 Other Carpal Bone Fractures

19.3.5.1 Triquetral Fractures

19.3.5.2 Hamate Fractures

19.3.6 Stress Fractures

19.3.7 Mimickers of Osseous Trauma

19.4 Wrist Ligamentous Injury

19.4.1 Interosseous Ligaments

19.4.1.1 Anatomy

Scapholunate Ligament (SLL)

Lunotriquetral Ligament (LTL)

19.4.1.2 Normal MRI Appearances

Scapholunate Ligament (SLL)

Lunotriquetral Ligament (LTL)

19.4.1.3 Pathology

SLL Tear

LTL Tear

19.4.1.4 Wrist Dynamic and Instability

19.4.2 Wrist Extrinsic Ligaments

19.4.3 Triangular Fibrocartilage Complex (TFCC)

19.4.3.1 Anatomy

Radial Attachment

Ulnar Attachment

Vascularity to the TFCC

TFCC Shape During Rotation

Ulnar Variance

19.4.3.2 Pathology

19.5 Finger Ligamentous Injury

19.5.1 Ulnar Collateral Ligament of the Thumb

19.5.1.1 Anatomy and Mechanism of Injury

19.5.1.2 MRI

19.5.2 Finger Tendon-Related Injury

19.5.2.1 Finger Flexor Tendon Injuries

Related Anatomy

Flexor Tendon Injury

Pulley Injuries

19.5.2.2 Finger Extensor Mechanism

Related Anatomy

Injuries

Imaging

References

20: Wrist and Hand Injuries: US Pitfalls

20.1 Introduction