How Is a Head and Neck Ultrasound Done?

A head and neck ultrasound is a painless, radiation-free scan in which a technologist or physician presses a small handheld probe against your skin, gliding it methodically across the front and sides of your neck while a screen displays live images of the structures underneath. The whole exam typically takes somewhere between ten and thirty minutes, depending on what needs to be evaluated, and requires almost no preparation on your part. Despite that simplicity, the technique can reveal a surprising amount about your thyroid, lymph nodes, salivary glands, blood vessels, and surrounding soft tissues.

What Happens Before the Scan Starts

There is essentially no special preparation for a standard head and neck ultrasound. You do not need to fast, stop medications, or change your routine. A salivary gland exam requires no patient preparation at all, and the complete scan of all four major salivary glands takes only about five to ten minutes.¹ You will be asked to lie on your back on an exam table with your neck extended, usually with a pillow or a triangular foam pad tucked under your shoulders and lower neck for support.² That gentle backward tilt opens up the front of the neck and makes the structures more accessible to the probe. If you have significant neck pain or limited range of motion, let the sonographer know beforehand so they can adjust your position.

Warm gel is applied directly to your skin. The gel eliminates the tiny air gap between the probe and your body, which would otherwise block the sound waves. In pediatric exams, warming the gel is especially emphasized because cold gel on a child’s neck can cause squirming and fussiness, and a cooperative patient makes for better images.³ You might be asked to remove necklaces or scarves, but otherwise you stay clothed.

How the Probe Moves Through the Neck

The examiner uses a linear transducer, a flat-faced probe that produces a rectangular image ideal for shallow structures. For most adult neck exams, the probe operates in a frequency range of roughly 8 to 15 MHz, though newer transducers can exceed 20 MHz for extremely detailed views of skin, superficial nerves, and thin muscles.⁴ Higher frequency means sharper resolution for things close to the surface, which is exactly where most neck anatomy sits.

The scan usually begins at the midline under your chin, in the submental region, with the probe held in a transverse (side-to-side) orientation. From there the examiner sweeps the probe laterally toward each side of the neck. When scanning one side, the sonographer may ask you to turn your head away from the side being examined. This head turn pulls the jaw out of the way and lets the probe move freely along the full length of the neck from jawline to collarbone.² You will feel moderate pressure as the probe is angled into different positions, but it should not be painful.

The examiner takes both transverse and longitudinal images of whatever structure is being assessed, meaning the probe gets rotated 90 degrees at each location. These two perpendicular views together give a three-dimensional sense of the shape, size, and internal features of a structure. The process is repeated systematically across the entire neck so that nothing is missed.

What Specific Structures Get Examined

The phrase “head and neck ultrasound” is broad and covers several different exams that follow their own protocols. Which structures the sonographer focuses on depends on why the scan was ordered.

Thyroid and Parathyroid Glands

Thyroid ultrasound is one of the most common reasons for a neck scan. The butterfly-shaped thyroid gland sits at the front of the lower neck, and ultrasound can detect nodules, cysts, enlargement, and signs of inflammation. For suspected parathyroid problems, the scan extends from the level where the carotid artery splits (roughly mid-neck) all the way down to the thoracic inlet at the base of the neck, covering both sides in longitudinal and transverse views.⁵ Parathyroid glands are tiny and sit behind the thyroid, so the examiner needs to be methodical to spot an enlarged one.

Lymph Nodes

Surgeons and radiologists describe lymph node locations using a standardized map of neck “levels,” numbered roughly I through VI, that correspond to anatomic compartments running from beneath the chin down to the collarbones and around the sides of the neck.⁶ Assigning a node to a specific level matters because it helps clinicians figure out where a cancer might be coming from and how to plan surgery. A thorough lymph node survey sweeps through all these levels on both sides. The examiner looks at each node’s shape, size, internal echo pattern, and border characteristics, noting anything that looks abnormal.

Salivary Glands

When the exam targets the salivary glands, the focus is on the two largest pairs: the parotid glands (in front of and below each ear) and the submandibular glands (under the jawline on each side). The sublingual glands, tucked under the tongue, are generally too small and too awkwardly positioned for reliable ultrasound assessment. For the parotid, the probe is placed longitudinally alongside the ear’s tragus and then moved forward across the cheek, with a transverse sweep from top to bottom. The deep lobe of the parotid can be visualized by angling the probe between the angle of the jaw and the mastoid bone behind the ear. For the submandibular gland, the examiner starts at the chin and moves the probe outward and downward along the underside of the jaw.⁷

How Blood Flow Is Assessed

Many head and neck ultrasounds include a Doppler component. You may hear a whooshing sound from the machine’s speakers when this mode is activated. Doppler ultrasound detects blood flow by measuring the frequency shift of sound waves bouncing off moving red blood cells. In the neck, this is used for two broad purposes.

The first is vascular screening: checking the carotid and vertebral arteries for narrowing or plaque, which is relevant if there is concern about stroke risk. The second is characterizing masses and lymph nodes. Normal, healthy lymph nodes tend to receive blood through a single central vessel (the hilum), while suspicious nodes may show blood flow entering from the edges, scattered through the interior, or distributed unevenly.⁸ The examiner classifies the vascular pattern as hilar, peripheral, spotted, or mixed. Quantitative measures of blood-flow density inside a node can also help distinguish benign from malignant enlargement, with small cancerous nodes sometimes showing higher blood-flow density than healthy ones of the same size.⁹

Advanced Imaging Techniques That May Be Added

A standard greyscale-plus-Doppler scan is the backbone of most head and neck ultrasounds, but some exams add specialized modes to get more information.

Elastography

Elastography measures tissue stiffness. The idea is straightforward: cancerous tissue tends to be stiffer than healthy tissue because tumor cells crowd together and stimulate fibrous growth. The machine either tracks how the tissue deforms when the examiner presses on it (strain elastography) or sends a brief push pulse and measures how fast the resulting shear wave travels through the tissue (shear wave elastography). In lymph node evaluation, metastatic nodes generally register as stiffer than benign ones.¹⁰ For thyroid nodules, studies have documented higher accuracy for elastography in distinguishing malignant from benign nodules compared with conventional ultrasound alone.¹¹ From the patient’s perspective, elastography feels identical to a regular ultrasound; the difference is in the software processing happening inside the machine.

Contrast-Enhanced Ultrasound

Contrast-enhanced ultrasound (CEUS) involves injecting a small amount of microbubble contrast agent into a vein, usually in the arm. These microscopic gas-filled bubbles circulate through the bloodstream and light up on the ultrasound image, revealing fine details of how blood flows into and through a lymph node or mass. Specific patterns carry diagnostic weight: for instance, a centripetal enhancement pattern (blood flowing inward from the edges rather than outward from the center), irregular perfusion defects, and uneven contrast distribution have been linked to malignant lymph nodes.¹² CEUS is especially useful when standard B-mode imaging produces an uncertain result and clinicians need more information before deciding on biopsy.¹³ The microbubbles are not iodine-based and are generally well tolerated, breaking down within minutes.

When the Scan Leads to a Biopsy

If the ultrasound reveals a suspicious nodule or lymph node, the next step is often an ultrasound-guided fine-needle aspiration, sometimes done during the same appointment. The sonographer or physician keeps the probe on your neck to watch the needle in real time as it enters the target. Most practitioners position the needle along the long axis of the probe so it stays visible on the screen throughout the procedure.¹⁴ A freehand technique is most common, meaning the needle is held separately from the probe rather than locked into a mechanical guide.

The needle used is thin, typically a 22-gauge needle for fine-needle aspiration, and the procedure usually does not require local anesthesia. In surveys of head and neck surgeons who perform their own ultrasound-guided biopsies, roughly 80% reported not using local anesthesia for fine-needle aspiration, relying on the small needle gauge alone to keep discomfort minimal. For core-needle biopsies, which use a slightly larger 18-gauge needle, local numbing is more common. The entire biopsy takes only a few minutes, and having it done under direct ultrasound visualization reduces the risk of hitting blood vessels or other sensitive structures.¹⁴

Head and Neck Ultrasound in Children

Ultrasound is the preferred first-line imaging tool for evaluating neck lumps in children, and for good reason: it avoids radiation, does not require iodine-based contrast, and generally does not need sedation or anesthesia.¹⁵ The vast majority of palpable head and neck masses in the pediatric population turn out to be benign, so a quick, cost-effective scan can often provide reassurance without exposing a child to anything invasive.

The exam technique in children is almost identical to the adult version. High-frequency probes in the 10 to 15 MHz range are used, and the child lies supine with a comfortable cushion under the shoulders. One notable difference is that in children and adolescents, the thymus gland can sometimes be seen in the lower neck above the collarbones, appearing as a soft, slightly dark structure with thin bright stripes running through it. This is normal and its appearance changes with age, becoming brighter on ultrasound as the child grows.³ Recognizing ectopic or cervical thymus tissue prevents it from being mistaken for something concerning.

Where Ultrasound Runs Into Limits

Ultrasound excels at imaging superficial soft tissue, but the neck has a few built-in obstacles. The thyroid cartilage (the rigid structure of the voice box) and the air-filled trachea block sound waves, creating shadows that limit what the examiner can see behind them. Similarly, the skull’s bony acoustic window is narrow, which constrains views of structures near the skull base.¹⁶ Deep structures in the neck, particularly the retropharyngeal space behind the throat, are difficult or impossible to reach with a surface probe, and CT or MRI may be needed for a complete picture.

The exam is also operator-dependent in a way that CT and MRI are not. A well-trained sonographer or head-and-neck specialist can detect subtle findings that a less experienced examiner might miss. Some institutions have responded by grading their sonographers by experience level; in one study evaluating lymph node metastasis detection, nodes were examined by a level-III (senior) head and neck sonologist and mapped to standardized anatomical levels before surgery.¹⁷ If your scan is being done specifically to evaluate a known or suspected cancer, it is worth confirming that the person holding the probe has specific experience in head and neck imaging.

Body habitus matters, too. A thick or muscular neck pushes structures deeper, reducing image quality at the frequencies optimized for superficial work. Conversely, very thin patients with little subcutaneous tissue can present their own challenge because the probe may sit too close to the structures, requiring a standoff pad to get the focal zone right.

Safety Considerations

Diagnostic ultrasound is considered one of the safest imaging modalities available. It uses no ionizing radiation, which is why it is freely used in pregnancy and pediatric care. Ultrasound machines display two safety indices on screen during every exam: a mechanical index (MI), which reflects the potential for tissue disruption from sound-wave pressure, and a thermal index (TI), which reflects how much heating the beam could produce.¹⁸ At the power levels used in standard diagnostic neck imaging, both indices stay well within established safety limits. There are no known cumulative effects, and repeat scans carry no added risk, which is why ultrasound is the go-to tool for serial monitoring of thyroid nodules or post-treatment lymph node surveillance.

Artificial Intelligence in Neck Ultrasound

Some newer ultrasound machines now come with built-in software that uses deep learning to help characterize findings in real time. The most widely deployed example for the neck is a system that, after the examiner selects a region of interest around a thyroid nodule, automatically analyzes its grayscale features (internal structure, echogenicity, borders, orientation, and shape) and suggests whether the nodule looks benign or suspicious.¹⁹ These tools are designed to support the clinician’s judgment rather than replace it. The final decision about whether to biopsy still rests with the physician. But the technology is evolving quickly, and AI-assisted analysis may become a routine part of how neck ultrasound findings are interpreted in the coming years.

Ultrasound During Surgery

Head and neck ultrasound is not limited to the clinic. Surgeons are increasingly using portable ultrasound probes in the operating room, particularly during oral cancer surgery. When removing a tongue tumor, for instance, the surgeon can place a small intraoral ultrasound probe directly against the tissue to measure how deep the tumor extends and to check whether the planned surgical margin will be wide enough. Early experience suggests that intraoral ultrasound can accurately measure the depth of invasion and may help ensure clearer deep margins.²⁰ Newer systems use three-dimensional ultrasound imaging to assess margins on the excised specimen itself, right there in the operating room, potentially reducing the need for additional surgery if margins are found to be inadequate on later pathology review.²¹

There is also a growing movement toward surgeon-performed ultrasound in the clinic itself, outside the radiology department. Ear, nose, and throat surgeons who perform their own scans and biopsies can sometimes condense what used to be multiple appointments into a single visit, getting a scan, a biopsy, and even same-day cytology results in one session.¹⁴ For patients being evaluated for possible head and neck cancer, shaving weeks off the diagnostic timeline can have real consequences for treatment planning and peace of mind.