Topics

Topic

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Scapula

The scapula, or shoulder blade, is a flat, triangular bone located on the posterior thoracic wall. It connects the humerus with the clavicle, forming the shoulder girdle, and provides multiple sites for muscle attachment, contributing to the mobility and stability of the shoulder joint. Its key landmarks include the spine, acromion, coracoid process, glenoid cavity, and borders (superior, medial, lateral). The scapula plays a central role in upper limb movement, serving as a lever for muscle action and a platform for glenohumeral articulation. The bone has a thin cortical shell with a trabecular internal structure, and its surface contours can be appreciated on imaging for assessment of fractures, degenerative changes, or anatomical variations.

Synonyms

  • Shoulder blade

  • Scapular bone

  • Os scapulae

Function

  • Forms part of the shoulder girdle, connecting humerus and clavicle

  • Provides attachment sites for multiple muscles including the rotator cuff, trapezius, and deltoid

  • Supports upper limb mobility and stability, facilitating abduction, rotation, and flexion of the arm

  • Contributes to force transmission from the upper limb to the axial skeleton

MRI Appearance
T1-weighted images:

  • Cortical bone appears very low signal (black)

  • Bone marrow shows intermediate to high signal, depending on fatty content

  • Surrounding muscles and soft tissue are intermediate signal, while fat is hyperintense

  • Fractures, marrow edema, or tumors can be seen as low- to intermediate signal cortical disruption or high signal within marrow

T2-weighted images:

  • Cortical bone remains signal void

  • Marrow edema, inflammation, or soft tissue lesions appear hyperintense

  • Muscle, tendon, and connective tissue are intermediate signal, while fluid collections are bright

STIR (Short Tau Inversion Recovery):

  • Suppresses fat signal, highlighting edema, inflammation, or marrow lesions

  • Normal cortical bone is dark, marrow is intermediate to low signal

  • Pathology such as fractures, contusions, or neoplasms appear bright hyperintense

CT Appearance

  • Cortical bone is hyperdense and sharply defined

  • Trabecular bone is less dense, providing internal contrast

  • Useful for fracture detection, anatomical assessment, and surgical planning

  • Surrounding soft tissues are visible with intermediate density, while air (if present in nearby thoracic structures) is hypodense

  • Axial, coronal, and sagittal planes allow complete evaluation of scapular spine, glenoid cavity, acromion, and coracoid

MRI images

Scapula 3D

MRI image

scapula MRI axial image -img-00000-00000

MRI image

Scapula sag mri image

CT image

scapula ct axial image -img-00000-00000