MRI of Chest and Shoulder Joint

MRI of Chest and Shoulder Joint

• The presentation is about MRI of the chest and shoulder joint
• The presenter is Dr. Hayder Jasim Taher, PhD of Medical Imaging

Outline of the Presentation

• Patient preparation and safety
• Precautions
• Contrast media
  • Positive relaxation agents (T1 agents)
  • Negative relaxation agents (T2 agents)
  • Gadolinium

Anatomical Overview (Chest)

• The chest, or thorax, is the bony cage region between the neck and abdomen
• The upper boundary, the thoracic inlet, is formed by the first thoracic vertebra, the first ribs, and the upper margin of the manubrium
• Inferiorly, the chest extends to the level of the thoracic outlet, marked by the diaphragm, which spans between the inferior margin of the sternum and the upper lumbar vertebra

Common Indications (Chest)

• Mediastinal mass: Examples include lymphoma and congenital cysts
• Neurogenic lesions: Examples include thoracic meningoceles and malignant nerve sheath tumors
• Differentiation between lymph nodes and vascular anomalies
• Assessment of vascular anomalies Examples include thoracic aortic aneurysms (evaluated in conjunction with MRA)

MRI Procedure (Chest)

• Patient position: Supine (head first). Patients with claustrophobia may prefer a feet-first orientation

• Coil: Torso-array coil used

• Scout slice placement (axial slice):

  • Alignment: True axial
  • Coverage: Superior to inferior (thoracic inlet to diaphragmatic crura), lateral to medial (chest wall on each side), posterior to anterior (thoracic spinous processes to sternum)
  • Demonstrates mediastinum contents, morphology of the great vessels and heart, and lymph node location and size

• **Scout slice placement (Coronal slice):**Axial localizer for coronal slice. -Alignment: True coronal. -Coverage: As for axial plane. -Demonstrates costophrenic angles and lung apices

• MRI Sequences (Chest): Various sequences like T1WI (FSE), T2WI (FSE), fat suppression, DWI sequence, dynamic study + contrast (GAD-based contrast), and MRA are used to provide detailed anatomical information from axial and coronal sections(5mm slice thickness). Used to assess tissue differences in water content, assess lesions, and characterize vascular anomalies

Anatomical Overview (Shoulder)

• The shoulder joint is formed by the articulation between the head of the humerus and the glenoid cavity (fossa) of the scapula
• The larger humeral head compared to the glenoid gives the joint a wide range of movement but also instability
• The glenoid fossa is deepened by the glenoid labrum to reduce the instability

Indications (Shoulder)

• Diagnosis and evaluation of impingement syndrome and instability
• Evaluation of frozen shoulder syndrome
• Rotator cuff injury
• Pectoralis tear

MRI Procedure (Shoulder)

• Patient position: Supine, head first; offset the patient left or right and bring the shoulder close to the magnet isocenter to minimize motion (oblique the patient, shoulder of interest down)
• Coil: Multi-channel shoulder coil
• Straps: Recheck straps to secure immobilization
• **Scout slice placement (axial slice):**Coronal localizer. Alignment usually true axial(adjust angulation if humeral head is abnormally high) from above acromioclavicular joint through surgical neck of humerus. Slice acquisition has superior to inferior orientation.
• Scout slice placement (sagittal slice): Axial localizer. Lateral to medial alignment. Parallel to the glenoid fossa.Entire deltoid muscle through glenoid fossa.
• Scout slice placement (coronal slice): Axial localizer. Anterior to posterior slice acquisition. Perpendicular to glenoid fossa, parallel to supraspinatus muscle. Subscapularis muscle to supraspinatus tendon

MRI Sequences (Shoulder)

• Specific sequences (TR, TE, FA, ETL) and slice thickness (e.g., T1WI (FSE), and T2WI (FSE)) are used to provide detailed information for evaluation (table included in the slides)