Class 20 - Sternum and SC Joints

Class Overview

  • Class Title: MRT 1144 Essential Imaging of the Sternum and Sternoclavicular Joints

Anatomy Overview

  • Sternum and Bony Thorax:

    • Comprises 12 pairs of ribs.

    • Sternum consists of: manubrium, body (corpus/gladiolus), and xiphoid process (level of T9-T10).

    • Clavicle articulates at the sternoclavicular joint.

Key Landmarks of the Sternum

  • Topographic Landmarks:

    • Jugular notch: Located at T2-T3.

    • Sternal angle: T4-T5.

    • Xiphoid tip: T10.

    • Other significant landmarks include T8, T9, T10, T11, and L1-L3.

Rib Anatomy

  • Features of a Typical Rib (Inferior View):

    • Head, neck, tubercle, angle, shaft, and sternal end (anterior).

Joint Articulations

  • Bony Thorax Joint Types:

    • Synovial joints include:

      • Costotransverse Joint: Plane (gliding) motion, diarthrodial.

      • Costovertebral Joint: Plane (gliding) motion, diarthrodial.

Objectives for Imaging Procedures

  • Imaging procedures aimed at the sternum and SC joints include:

    • PA Oblique (RAO).

    • Lateral views for both sternum and SC joints.

    • PA and PA obliques for body rotation.

General Procedural Guidelines for Imaging

  • Patient Preparation:

    • Remove any artifacts (e.g., necklaces, clothing).

    • Secure patient possessions appropriately.

  • Patient Positioning:

    • Analysis for ambulatory and nonambulatory patients, ensuring comfort.

  • IR/Collimated Field Size:

    • Adjust collimation based on anatomy of interest, ensuring minimal field size for sternum and SC joint while considering larger sizes for rib images.

  • Source-Image Receptor Distance (SID):

    • Recommended Standardization:

      • PA oblique sternum: 30 inches.

      • Lateral sternum: 72 inches.

      • Rib x-rays: 100 cm SID.

  • ID Markers:

    • Include right/left side markers; avoid digital annotations.

  • Radiation Protection:

    • Implement gonadal shielding and proper collimation.

  • Patient Instructions:

    • Clear communication regarding positions and respiration instructions to minimize retakes.

Essential Projections for Imaging the Bony Thorax

  • Sternum Imaging:

    • PA Oblique (RAO) and Lateral views.

    • Ensure proper collimation of 10 x 12 inches.

  • Positioning for PA Oblique (RAO):

    • 15-20 degree rotation; shoulders and hips aligned; top of IR positioned above jugular notch.

  • CR Placement for RAO:

    • Perpendicular to the elevated side, at level of T7.

    • Slow, shallow breathing technique recommended.

Lateral Sternum Imaging

  • Patient Positioning:

    • Patients must be upright or lateral recumbent; proper arm positioning to prevent obscuration of the sternum.

  • CR for Lateral Sternum:

    • Perpendicular to IR, entering the lateral border of the sternum.

    • Suspension of respiration at deep inspiration.

Evaluation Criteria for Imaging Projections

  • PA Oblique Sternum:

    • Check for visualization of clavicles, manubrium, sternal angle, and entire sternum with correct rotation and optimal exposure.

  • Lateral Sternum:

    • Clear visualization without rotation, showing the manubrium and xiphoid process.

Projections of SC Joints

  • Essential projections include PA and PA oblique positions with appropriate patient positioning and CR orientation. Expectation for proper collimation and the visual capture of joints in central frame.