Hypopharynx
The hypopharynx forms the most inferior portion of the pharynx, being the continuation of the oropharynx superiorly and esophagus inferiorly. Medical imaging of this anatomical region provides essential diagnostic information for various conditions affecting the lower throat. Cross-sectional imaging with CT and MRI plays an important role in evaluating hypopharyngeal pathology.
What Is the Hypopharynx
The pharynx is a hollow muscular tube which extends from the skull base to the inferior border of the cricoid cartilage, and is an integral part of the upper aerodigestive tract. The hypopharynx, also called the laryngopharynx, represents the lowest part of your throat. This important structure connects your mouth and nose to your breathing passages and food pipe.
The hypopharynx begins as the continuation of the oropharynx at the pharyngoepiglottic fold (which is at the level of the hyoid bone) superiorly, and extends inferiorly to the level of the inferior aspect of the cricoid cartilage. Think of it as a funnel-shaped passageway that helps direct both air to your lungs and food to your stomach.
Hypopharynx Anatomy and Location
Your hypopharyngeal region has three main parts that doctors look for on imaging studies. The three components of the hypopharynx are the posterior pharyngeal wall, the pyriform sinuses, and the postcricoid region. Each of these areas serves important functions in swallowing and breathing.
The pyriform sinuses are small pockets on either side of your voice box. The postcricoid area sits behind your voice box, while the posterior pharyngeal wall forms the back wall of your throat. It is a mucosa-lined, muscular tube with its posterolateral walls formed by the inferior constrictor muscle and anterior wall by laryngeal cartilages.
Medical Imaging of the Hypopharynx
When doctors need to examine your hypopharynx, they typically use advanced imaging techniques. Imaging is frequently required to supplement clinical assessment and this typically involves MRI and CT. These imaging methods allow doctors to see details that cannot be observed during a regular physical examination.
CT Scans of the Hypopharyngeal Area
CT is a non-invasive examination technique, which is able to demonstrate laryngeal and pharyngeal anatomy in a three-dimensional manner and give qualified information in addition to the clinical findings. Computed tomography scans provide detailed cross-sectional images of your hypopharynx, showing the soft tissues, cartilage, and surrounding structures.
During a CT scan of your neck and throat area, you may receive contrast material through an IV. This contrast helps doctors see blood vessels and identify any abnormal areas more clearly. The entire scan usually takes just a few minutes.
MRI Imaging of the Lower Throat
In many centres, MRI can be done to image the larynx and hypopharynx. Magnetic resonance imaging offers excellent detail of soft tissues without using radiation. MRI scans can show the muscles, blood vessels, and other structures around your hypopharynx.
Specialized Imaging Techniques
Sometimes doctors use additional imaging methods to examine your hypopharynx. Barium swallow studies involve drinking a chalky substance that shows up on X-rays, allowing doctors to watch how your throat works during swallowing. PET scans may be used if doctors are concerned about cancer.
Common Hypopharynx Problems
Several conditions can affect your hypopharyngeal area. The spectrum of pathological changes in anatomical sections of the hypopharynx ranges from benign pathologies to hypopharyngeal carcinoma. Understanding these conditions can help you discuss your imaging results with your healthcare team.
Inflammation and Swelling
Infections, acid reflux, or allergic reactions can cause inflammation in your hypopharynx. On imaging studies, this might appear as thickening of the throat walls or fluid collection. Most inflammatory conditions respond well to medical treatment.
Benign Growths
Non-cancerous growths like cysts or polyps can develop in the hypopharyngeal region. Many of these can be detected on clinical and endoscopic examination. However, cross-sectional imaging frequently provides useful additional information. These benign conditions typically have characteristic appearances on CT or MRI scans.
Hypopharynx Cancer and Imaging
Cross-sectional imaging with CT and MR imaging plays an important role in the evaluation of cancers of the hypopharynx and cervical esophagus. Cancer in this area requires careful evaluation to determine the extent of disease and plan appropriate treatment.
Detecting Hypopharyngeal Cancer
Clinical examination, including endoscopy, often fails to detect the full extent of this tumor as it has high propensity to grow in submucosal fashion. This is why imaging studies are so important for cancer detection and staging.
Cancer in the hypopharynx often appears as irregular thickening or masses on CT and MRI scans. Doctors look for changes in the normal anatomy and may use contrast to better visualize the extent of cancer.
Staging and Treatment Planning
When hypopharyngeal cancer is diagnosed, imaging helps determine how far the cancer has spread. The combination of clinical exam and cross-sectional imaging allows tumors to be staged accurately. This information is crucial for selecting the best treatment approach.
Advanced imaging techniques can show whether cancer has spread to nearby lymph nodes, invaded cartilage, or affected other structures. This information helps your medical team create a personalized treatment plan.
Understanding Your Imaging Results
When reviewing your hypopharynx imaging results, remember that many findings are benign or represent normal variations. Incidental benign findings are also common in pharyngeal imaging and it is important to have an awareness of these in order to avoid unnecessary further investigation.
Imaging is important in regions which are clinically difficult to assess. Imaging helps determine the extent of hypopharyngeal abnormalities and to plan the optimal therapy for the patient. Your doctor will correlate your imaging findings with your symptoms and physical examination to reach the most accurate diagnosis.
Next Steps After Hypopharynx Imaging
If your imaging study shows concerning findings, your doctor may recommend additional tests or specialist consultation. These might include endoscopic examination, biopsy, or additional imaging studies. Remember that many hypopharyngeal conditions are treatable, especially when detected early.
Understanding what the hypopharynx is and how medical imaging evaluates this area can help you feel more informed. Always discuss your specific results and any concerns with your doctor, who can explain your individual situation and recommend appropriate next steps based on your imaging findings and overall health.
References
- Radiopaedia. Hypopharynx. Available at: https://radiopaedia.org/articles/hypopharynx
- Kavanagh RG, O’Brien JC, O’Sullivan LE, et al. Imaging of pharyngeal pathology. Insights Imaging. 2023;14(1):144. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC10461270/
- Becker M, Burkhardt K, Dulguerov P, Allal A. Imaging of the larynx and hypopharynx. Eur J Radiol. 2008;66(3):460-479. Available at: https://pubmed.ncbi.nlm.nih.gov/18495402/