Study Notes on Head and Neck Ultrasound Introduction

Introduction to Head and Neck Ultrasound

  • Lecture Reminder

    • Students can ask questions via Padlet or email the instructor.

  • Session Objectives

    • Importance of understanding the objectives outlined for the session.

Utility of Head and Neck Ultrasound

  • Definition of Head and Neck Ultrasound

    • Refers primarily to ocular ultrasound rather than head structures.

    • Focus on ocular ultrasound will be addressed later in the lecture.

  • Importance of Ocular Ultrasound

    • Primarily used in traumatic situations for quick diagnostics in Emergency Departments (ED).

  • Neck Ultrasound

    • Common use in medical practice due to superficial anatomy.

    • Quick imaging to diagnose neck issues.

  • Clinical Correlates for Neck Ultrasound

    • Neck ultrasound finds various clinical concerns, often requiring follow-up diagnostics:

    • Physical exams

    • Patient histories

    • Lab tests

    • Biopsies

    • Not a stand-alone diagnostic tool.

    • Common areas of focus:

    • Thyroid gland

    • Lymph nodes

    • Pharyngeal arch/brachial cleft cysts.

Thyroid Gland in Ultrasound

  • Anatomy Focus

    • Components examined include:

    • Left lobe

    • Right lobe

    • Isthmus

    • Pyramidal lobes (when present).

    • Sonographers spend significant time examining thyroid glands based on referrals from primary care.

  • Normal Anatomy vs Pathology

    • Emphasis on recognizing normal anatomy as part of ultrasound education for first-year medical students.

    • Thyroid nodules will be discussed in-depth, emphasizing normal anatomy identification.

Patient Preparation and Setup for Neck Ultrasound

  • Patient Guidelines

    • Removal of:

    • Neck jewelry

    • High-neck clothing.

    • Positioning of Patient

    • Supine position throughout the exam

    • Use of a pillow

      • Provides hyperextension of the neck, improving access to structures.

  • Alternate uses of supports such as:

    • Sweatshirts or paper towel rolls for proper neck positioning.

Probe and Settings

  • Equipment

    • Use of linear probe for neck ultrasound.

    • Settings vary by machine but generally set to:

    • Superficial settings (i.e., carotid, thyroid, neck).

Scanning Order

  • Standard procedure:

    • Start on the right side, moving to the left, while scanning:

    • Inferior to superior.

    • Key structures to locate:

    • Sternocleidomastoid muscle

    • Strap muscles (sternohyoid and sternothyroid)

    • Common carotid artery

    • Internal jugular vein

    • Vagus nerve

    • Thyroid gland (both lobes)

    • Trachea, easily identifiable by C-shaped hyaline cartilage rings.

Additional Anatomy Review

  • Highlight important anatomical structures for successful ultrasound exams:

    • Scanning method from:

    • Right inferior to right superior

    • Midline evaluation

    • Left inferior to left superior.

    • Components seen:

    • Sternocleidomastoid:

      • May observe attachment points and hyperechoic rings of cartilage in trachea.

    • Identification of hyperechoic and hypoechoic structures.

    • Thyroid gland arrangement around the trachea in midline images.

Conducting the Ultrasound Exam

  • Starting in a transverse view:

    • Ensure patient is supine and hyperextended with appropriate positioning.

  • Scan Procedure:

    • Begin from right hand side in an inferior position, scanning right-to-left, inferior to superior.

  • Image Identification:

    • Initial visualization will likely include:

    • Sternocleidomastoid muscles,

    • Strap muscles,

    • Tracheal cartilage rings.

  • Thyroid Visualization:

    • Appearance of healthy thyroid as a homogenous structure with minimal vessel visibility.

Doppler Application in Neck Ultrasound

  • Transition to longitudinal view:

    • Allow visualization of:

    • Common carotid artery

    • Internal jugular vein

    • Important Doppler notes:

    • Understand what red and blue colors represent:

      • Red = towards the probe

      • Blue = away from the probe.

  • Key Anatomical Structure Observations:

    • Continue monitoring changes in internal jugular vein shape with respiration and how it differs from the common carotid artery.

Examination of Lateral and Anterior Views

  • Evaluations include:

    • Analyse both lateral views to assess:

    • External anatomy (sternocleidomastoid, strap muscles) and internal vasculature (common carotid, internal jugular).

  • Anterior midline focus leads to observations of:

    • Trachea

    • Thyroid Lobes

    • Isolated observation of trachea and thyroid structures from a central position.

Vocal Apparatus in Ultrasound: Non-Assessment

  • Not mandatory for lab focus but may be assessed if time allows.

  • Clinical Focus: Vocal growths and cyst assessment only when indicated by prior concerns.

Clinical Uses of Neck Ultrasound

  • Most common uses:

    • Diagnosis of thyroid issues

    • Non-invasive, cost-effective method to understand thyroid morphology.

  • Limitations of Ultrasound in Diagnostics:

    • Cannot distinguish benign and malignant conditions; requires follow-up tests and lab results for confirmation.

Thyroid Nodules and Cysts

  • Definitions:

    • Cysts:

    • Commonly fluid-filled, defined borders, typically benign.

    • Nodules:

    • May be irregular, heterogeneously textured, may indicate malignancy.

  • Clinical Follow-Up Guidance:

    • Palpation concerns lead to ultrasound for confirmation, potentially leading to further tests.

Thyroid Nodule Risk Classification and Management

  • Classifications based on characteristics observed during ultrasound:

    • Male, age extremes (under 20, over 60), rapid growth, nodule size > 4cm, symptoms (hoarseness, dysphagia), and heterogeneity are red flags for malignancy.

  • Doppler ultrasound application on nodules can indicate vascularity and thus risk for malignancy.

Statistics Related to Thyroid Nodules

  • Malignancy Statistics:

    • Approximately 5% of biopsied thyroid nodules are malignant.

    • Majority of biopsied cases (69%) show benign findings.

    • Presence of concerning features (size, growth rates) prompts further diagnostic evaluations.

Summary of Clinical Indications for Head and Neck Ultrasound

  • Reinforcement of knowledge gained: identification of key structures and techniques during neck ultrasound.

  • Ocular Ultrasound: Focused on trauma diagnostics; not practiced in lab due to safety concerns.

  • Understanding ocular structures related to trauma assessments, including:

    • Detection of vitreous and retinal detachments post-trauma.

Conclusion

  • Final remarks and invitation for further questions or concerns.

  • Encouragement to apply knowledge gained throughout the course.