Gastric Point of Care Ultrasound in Adults: Image Acquisition and Interpretation

Summary

This protocol introduces two methods for image acquisition in gastric ultrasonography. Additionally, tips are provided for interpreting this information to assist in medical decision-making.

Abstract

Over the past two decades, diagnostic point-of-care ultrasound (POCUS) has emerged as a rapid and non-invasive bedside tool for addressing clinical inquiries related to gastric content. One emerging concern pertains to patients about to undergo sedation and/or endotracheal intubation: the elevated risk of aspiration from the patient's stomach contents. Aspiration of gastric contents into the lungs poses a serious and potentially life-threatening complication. This occurs more frequently when the stomach is considered "full" and can be affected by the techniques employed for airway management, making it potentially preventable. To mitigate the risk of peri-procedural aspiration, two distinct medical specialties (anesthesiology and critical care medicine) have independently developed techniques to utilize ultrasonography for identifying patients requiring "full stomach" precautions. Due to these separate specialties, the work of each group remains relatively unfamiliar outside its respective field. This article presents descriptions of both techniques for gastric ultrasound. Furthermore, it explains how these approaches can complement each other when one of them falls short. Regarding image acquisition, the article covers the following topics: indications and contraindications, selection of the appropriate probe, patient positioning, and troubleshooting. The article also delves into image interpretation, complete with example images. Additionally, it demonstrates how one of the two techniques can be employed to estimate gastric fluid volume. Lastly, the article briefly discusses medical decision-making based on the findings of this examination.

Introduction

Pulmonary aspiration of gastric contents can cause pneumonitis, pneumonia, and even death¹. Higher volume, the presence of particulate matter, and higher acidity of aspirate have been shown to increase the severity of this scenario. Numerous factors help guide a clinician in assessing the risk of aspiration, including comorbid diseases that may slow gastric emptying times, mechanical gastrointestinal obstruction, and timing of the last oral intake. Historically, the latter relies solely on an assessment of the patient's history, which can be unreliable and inaccurate. In addition, clinician judgment has been shown to be poor to fair at diagnosing a full stomach².

In 2011, a special task force appointed by the American Society of Anesthesiology (ASA) first published the guidelines for preoperative fasting, and these were updated in 2017^3,4. Although the ASA fasting guidelines are helpful, they are population-based and not tailored to specific clinical situations, and they recommend further consideration for patients with altered pathology, such as delayed gastric emptying or bowel obstruction. Furthermore, these guidelines rely on a patient who is an accurate historian and can correctly recall their last oral intake. Finally, the guidelines' recommended fasting intervals may not be sufficient to ensure an empty stomach in urgent or emergency situations.

To address gaps in the published fasting guidelines and identify patients at high risk of aspiration, diagnostic point-of-care ultrasound (POCUS) imaging protocols of the stomach have been developed and validated by two separate author groups: one group consisting of intensive care unit (ICU) physicians, and the other of anesthesiologists. The ICU group⁵ focused on critically ill patients requiring urgent endotracheal intubation and developed a method to screen these patients for gross gastric distension by evaluating the stomach through the left upper quadrant (LUQ). In the LUQ, the authors used the spleen as a sonographic window to visualize the gastric body in the coronal and transverse planes to screen for qualitative signs of gastric distension. When gross gastric distension was identified, the authors took special airway precautions to minimize the chance of aspiration (e.g., by placing a nasogastric tube for gastric decompression [if not contraindicated] before induction of general anesthesia and endotracheal intubation). Separately, a group of anesthesiologists focused on perioperative patients developed a technique for screening stomach contents that would not be expected in properly fasted patients with normal gastric emptying⁶. This technique involves placing the ultrasound probe in a sagittal plane in the epigastrium to visualize the gastric antrum. The technique allows for both qualitative detection of high-risk stomach contents and, in cases of clear fluid, quantitative estimation of gastric fluid volume.

By combining these two protocols into a hybrid approach, this manuscript will abide by the I-AIM framework to categorize the key steps in gastric ultrasonography: indications, acquisition, image interpretation, and medical decision-making⁷. However, since this Special Collection is focused on diagnostic POCUS image interpretation, this manuscript will only briefly cover image interpretation and will largely defer the discussion of medical decision-making, as this falls outside the scope of this Collection.

Indications
Gastric ultrasound has at least four possible indications. First, gastric ultrasound is indicated to screen for high-risk stomach contents prior to intubation or procedural sedation in situations when the patient's stomach volume and/or contents are either unknown or the history about gastric volume/contents is unreliable. In this setting, the gastric ultrasound exam is performed to risk-stratify the likelihood of pulmonary aspiration and adjust the patient's care to minimize this risk. Second, some intensivists have used gastric ultrasound to measure gastric residual volumes (GRV) in patients receiving enteral feeding⁸. In this case, assessing the gastric antrum can aid in the diagnosis of enteral feed intolerance and subsequently decrease the risk of aspiration pneumonia. Recently, gastric ultrasonography has been evaluated as a tool to measure antral cross-sectional area and has shown a strong correlation with GRV in ICU patients⁹. Third, gastric POCUS has been used to assess delayed bowel function and post-operative ileus in patients following surgical procedures¹⁰. Fourth, in pediatric patients, gastric ultrasound has been utilized to diagnose foreign body ingestion and pathologies such as pyloric stenosis¹¹. For other pediatric applications of gastric ultrasound, readers are referred to other sources. The remainder of this article will focus on gastric ultrasound in adults¹¹.

There are very few contraindications to gastric ultrasound because the exam is a non-invasive test that poses negligible direct harm to patients. The main absolute contraindication is patient refusal. Relative contraindications include any of the following: (1) dressings/wounds in the area of the usual scanning windows; (2) a lack of time to attempt the exam due to rapid deterioration of a patient's hemodynamic or clinical status; and (3) a very high or very low pre-test probability of a full stomach. Fortunately, the presence of intervening dressings/wounds can sometimes be addressed by choosing an alternate sonographic window. For example, if the anterior abdominal approach is obstructed, one can attempt a left lateral view and vice versa. A shortage of time can also be managed through deliberate practice, as studies have shown that gastric ultrasound can be performed expeditiously in expert hands¹². Finally, there are cases where the pre-test probability of a full stomach is either very low (e.g., a healthy patient properly fasted for surgery) or very high (e.g., a patient presenting with a known, fixed intestinal obstruction). In such cases, gastric ultrasound is relatively contraindicated because the test - like all diagnostic tests - is imperfect and has the potential to generate false positive and false negative results that can lead patients in an inappropriate direction.

Acquisition
For acquisition, it is recommended to begin with the subxiphoid sagittal approach to visualize the gastric antrum. The antrum represents an optimal anatomical location to measure gastric contents due to its consistent and superficial location. It constitutes the most dependent portion of the stomach and can be quickly identified in most patients⁶. Additionally, the gastric antrum dilates in a linear fashion as its contents increase, making it a suitable target for qualitatively assessing stomach contents and suggesting a risk stratification of gastric aspiration⁶. If the anterior sagittal window is not accessible (e.g., due to wounds/dressings) or provides indeterminate data, the left lateral window may offer useful qualitative data regarding a patient's gastric contents.

Regarding image interpretation and medical decision-making, the manuscript reviews a range of potential outcomes and explains how gastric ultrasound can be collaboratively used in distinct patient populations. Finally, the common pitfalls and limitations of these methods will be described.

Protocol

All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The exams can be performed using either a sector array (sometimes colloquially referred to as a "phased array") or a low-frequency curvilinear transducer based on the sonographers' preference. For the figures and scans, a curvilinear probe was used for the anterior sagittal views, while a sector array probe was used for the gastric body scans. The commercial details of the probes are provided in the Table of Materials.

1. Subxiphoid sagittal gastric antrum views (aka "Subxiphoid Views")

1. Supine view
   1. Patient positioning: place the patient in the supine position. If the patient is unable to tolerate being fully supine, up to 30 degrees head up is an acceptable alternative.
   2. Probe selection: select any low-frequency probe (e.g., curvilinear or sector array) (see Table of Materials).
   3. Mode selection: set the preset to abdominal mode.
   4. Probe placement
      1. Place the probe on the patient's sub-xiphoid region in the sagittal plane (Figure 1).
      2. Orient the probe marker in a cephalad direction.
   5. Image optimization
      1. Fan the probe from the patient's left to right until one can visualize the following structures on the screen: (1) liver on the left side of the screen; (2) pulsatile aorta in the long-axis deep in the image; and (2) gastric antrum just caudal and deep to the superficial liver edge (Figure 2).
      2. Ensure the abdominal aorta is positioned at the deeper edge of the image. If the inferior vena cava (IVC) is seen instead, correct the ultrasound beam angle if angled too far towards the patient's right. In this case, visualize the stomach at the pylorus level rather than the antrum. If that happens, adjust by fanning leftward until the aorta becomes visible. This is the appropriate position to analyze the gastric antrum (Figure 3).
         NOTE: If only the stomach is visible at the IVC level and not the aorta, the qualitative sonographic data is still valuable, but remember that this view has lower sensitivity for detecting a "high-risk" stomach. In such cases, a volume assessment will probably underestimate gastric volume (Figure 3).
      3. Identify the muscularis propria (hypoechoic, thickest gastric wall layer) to ensure focusing on the stomach. Large, dilated bowel can be misidentified as the gastric antrum (Figure 4).
         NOTE: The pancreas may be visible posterior to the gastric antrum (Figure 2).
   6. Image acquisition: click on Acquire to save a video clip of this sonographic view.
2. Right lateral decubitus view
   1. Patient positioning: position the patient in the right lateral decubitus (Figure 5).
   2. Probe selection: follow step 1.1.2.
   3. Mode selection: follow step 1.1.3.
   4. Probe placement: follow step 1.1.4.
   5. Image optimization: follow step 1.1.5.
   6. Image acquisition: follow step 1.1.6.
   7. Quantitative estimation of gastric volume
      1. If the gastric antrum appears to contain only clear liquids, quantify the total gastric volume by obtaining an image of the gastric antrum as described above, with the patient in the RLD position (refer to step 1.2.5).
      2. When a view of the gastric antrum is obtained during its maximal expansion, freeze the image.
      3. Activate the Trace tool and trace out the cross-sectional area of the gastric antrum along the outer hyperechoic layer of the wall representing the serosa (Figure 6).
         NOTE: An antral area greater than 10 cm²is unlikely consistent with normal baseline volume and suggests a "full stomach".
      4. Click on Save.
      5. Estimate the gastric fluid volume using the following formula¹³: stomach volume (mL) = 27 + 14.6 ACSA (in RLD) cm² − 1.28 x age (years).
         ​NOTE: This formula has been validated for clear liquids in the antrum. This formula was also validated in a separate study of morbidly obese individuals¹⁴.

2. Left upper quadrant (LUQ) gastric body views

1. If subxiphoid views are inadequate or inaccessible, proceed to evaluate left upper quadrant views (step 2.2 and step 2.3).
2. LUQ coronal gastric body view
   1. Patient positioning: follow step 1.1.1.
   2. Probe selection: follow step 1.1.2.
   3. Mode selection: follow step 1.1.3.
   4. Probe positioning
      1. Place the probe on the left mid-axillary line in the longitudinal plane with the orientation marker pointed toward the patient's head (Figure 7).
         NOTE: With the probe marker oriented in this direction, the thoracic cavity will appear on the left side of the ultrasound scanner and the right side will be the abdominal cavity.
   5. Image optimization
      1. Identify the spleen and left hemidiaphragm. The spleen is identified by its rounded capsular shape. The left hemidiaphragm appears as a hyperechoic line, superior to the spleen, and moves with the normal respiratory cycle.
      2. Once the spleen is identified, fan posteriorly to identify the kidney, which will appear as the oblong structure inferior and posterior to the spleen.
         NOTE: The spleen offers less of an acoustic window than the liver does on the right abdomen
      3. Once these landmarks are identified, angle the transducer in an anterior direction to obtain a view of the gastric body (Figure 7).
         NOTE: The anatomic structures will likely shift as the diaphragm moves. If possible, consider asking the patient to briefly hold his/her breath while the scans are being performed.
   6. Acquire the images following step 1.1.6.
3. LUQ anterior transverse gastric body view
   1. Patient positioning: follow step 1.1.1.
   2. Probe selection: follow step 1.1.2.
   3. Mode selection: follow step 1.1.3.
   4. Probe positioning
      1. Place the probe on the anterior surface of the patient's abdomen at approximately the mid-clavicular line, just caudal to the ribs (Figure 8). In order to fully assess the gastric body, it might be necessary to rotate the probe clockwise to an oblique view.
   5. Image optimization: fan the probe cranial-to-caudal until the gastric body is seen deep into the spleen.
   6. Acquire images folllowing step 1.1.6.

Representative Results

To ensure accurate visualization of the gastric antrum, it is necessary to probe deep enough to identify the aorta. Detecting the IVC instead places the scan at the gastric pylorus level, causing findings to underestimate genuine gastric content. While diagnostic utility remains for the gastric pylorus level, it iss less straightforward to interpret compared to the gastric antral view (Figure 3). Hence, a crucial task is to scan the great vessels and distinguish between the gastric antrum and pylorus (Figure 9). The aorta is identifiable by its thick, pulsating walls, distinct from the IVC. Color Doppler function can be employed for blood flow visualization when necessary. The absence of a discernible great vessel indicates the scan potentially cuts through the gastric body, yielding a non-standard image for subxiphoid gastric scanning (Figure 4 and Figure 9).

In the subxiphoid sagittal view, the gastric antrum lies caudal to the liver's tip and superficial to the aorta (Figure 2). In the presented example (Figure 2), the patient's antrum appears empty, with antral walls adjacent and minimal contents. When this finding repeats in both supine and right lateral decubitus (RLD) views, it signifies a normal, fasted state with low peri-procedural aspiration risk.

To evaluate any liquid contents in the gastric antrum, scans are taken in both supine and RLD positions. When the antrum is vacant in both supine and RLD positions, it is categorized as a Grade 0 antrum, indicating minimal aspiration risk. In such cases, the antral walls often touch or closely approximate each other (Figure 2). This is sometimes dubbed the "bull's eye" sign due to the hyperechoic mucosa of the stomach being encircled by the hypoechoic muscularis layer. If the antrum is empty in the supine position but contains a small volume of clear liquid in the RLD position, it is designated as a Grade 1 antrum, similarly indicating low peri-procedural aspiration risk. Grade 0 or 1 antrums typically correspond to antral areas under 10 cm² and gastric volumes below 1.5 mL/kg, in line with fasting conditions. Approximately 95% to 98% of fasting individuals exhibit a Grade 0 or Grade 1 antrum. Conversely, if clear fluid is present in both supine and RLD positions, it is identified as a Grade 2 antrum, signifying high peri-procedural aspiration risk. A Grade 2 antrum is less common during fasting (3%-5%) and generally relates to antral areas exceeding 10 cm² and gastric volumes surpassing 1.5 mL/kg, strongly suggesting a "full stomach". This antral grading system (Grades 0-2) applies specifically to clear liquid fluid¹⁵.

Multiple mathematical models have been proposed for the quantification of liquid contents within the gastric antrum^6,16. The formula listed above in step 1.2.7 is the simplest and has been validated in a wide range of adult patients, including the morbidly obese (>40 kg/m²)^13,15.

Using the example from Figure 6, the gastric volume would be calculated as such:

stomach volume (mL) = 27 + 14.6 ACSA (in RLD) cm²− 1.28 x age (years)

stomach volume (mL) = 27 + 14.6 x 4.03 − 1.28 x 47 = 25.3 mL

Several views require further clarification. When a patient has recently consumed clear liquids, an ultrasound assessment reveals an antrum containing both liquid and air bubbles. These bubbles refract light, creating an appearance akin to Figure 10, referred to as a "starry night" effect. Alternatively, if the patient has ingested solid foods, ultrasound beams struggle to penetrate air due to impedance, leading to a hyperechoic air-fluid boundary and an ensuing acoustic shadow. This results in a hyperechoic anterior antral wall with a blurry antrum, primarily displaying B-lines, referred to as the "frosted glass" appearance (Figure 11). Over time, usually 1-2 h, the air dissipates from the "frosted glass" image, leaving a hyperechoic, heterogeneous appearance where the posterior gastric wall becomes visible (Figure 12)¹⁷.

When subxiphoid views are unsatisfactory or not feasible due to patient conditions, left upper quadrant (LUQ) views can be an alternative. In LUQ views, the gastric body, due to its superficial position, typically appears at shallow depths in the average patient. In the LUQ coronal view, the gastric body should be anterior to the spleen. The presence of large bowel in this peri-splenic space might complicate gastric body identification. However, the absence of haustra distinguishes the gastric body from the large bowel. For instance, in Figure 7, liquid contents in the gastric body indicate a moderate risk of pulmonary aspiration for this patient.

In the left anterior transverse view, the gastric body's superficial location stands out (Figure 8). In this perspective, the splenic vessels often appear close to the gastric body. Figure 8 shows a distended gastric body containing both solid and liquid contents. The presence of solid contents alone suggests this patient's stomach isn't in a normal, fasted state and is potentially at a heightened risk of peri-procedural aspiration.

Figure 1: Subxiphoid sagittal view with the patient in the supine position. With the patient supine with the head of the bed slightly elevated, the probe is placed in the sub-xiphoid region in the parasagittal plane with the probe indicator pointing cranially. Please click here to view a larger version of this figure.

Figure 2: Subxiphoid sagittal gastric antrum view. An example of an optimized view (left) showing the following structures: the tip of the liver (L), the pulsatile aorta (Ao), and the gastric antrum lying between the other two structures. The stomach is identified by its thick, hypoechoic muscularis propria layer (circle and triangle) and the inner wall containing the rugae (gray arrow) (Right). In contrast to the stomach, the colon and small bowel have a purely hyperechoic rim on ultrasound (see Figure 4). Between the various cross-sections of the stomach, the gastric antrum is identified in the subxiphoid parasagittal plane by the presence of the abdominal aorta in the long-axis deep in the image (see Figure 3). Lastly, note the presence of the Pancreas (P) (Left), which typically lives just deep to the gastric antrum in this sonographic plane but is not always well seen. Please click here to view a larger version of this figure.

Figure 3: Subxiphoid sagittal gastric pylorus view. Similar to Figure 2, this subxiphoid parasagittal view shows the tip of the liver (L). But instead of the abdominal aorta, it shows the inferior vena cava (IVC) in the long-axis. The presence of the IVC in this imaging plane implies that the cross-section of the stomach being examined is not the gastric antrum but the gastric pylorus (GP). At the level of the pylorus, it becomes more challenging to screen for gastric distension. Specifically, an empty pylorus can be present even when the rest of the stomach is distended with contents. But if the pylorus is grossly distended with contents, this finding implies that the rest of the stomach is not in a normal fasted state. Please click here to view a larger version of this figure.

Figure 4: Inadequate visualization when attempting to obtain subxiphoid sagittal gastric antrum view. No great vessel was noted here. The thin-walled bowel appears hazy and should not be misinterpreted as the stomach. The stomach has a distinct appearance on ultrasound: unlike other segments of the bowel, the stomach is enveloped in a hypoechoic layer. This layer represents the muscular propria of the stomach. Please click here to view a larger version of this figure.

Figure 5: Subxiphoid sagittal view with the patient in the right lateral decubitus position (RLD). With the patient in the RLD position, the probe is placed in the sub-xiphoid region in the parasagittal plane with the probe indicator pointing cranially. Please click here to view a larger version of this figure.

Figure 6: Subxiphoid sagittal view showing quantitative estimation of liquid bowel contents. If the antrum contains clear liquid, as shown here, the sonographer can quantitate the contents using the formula in step 1.2.7. The "Trace" function was used to encircle the outside of the gastric muscularis layer. The ultrasound will generate a cross-sectional area of the (see upper left-hand corner of image). Please click here to view a larger version of this figure.

Figure 7: Left upper quadrant coronal gastric body view (aka "LUQ coronal view"). The probe is placed in the left midaxillary line to obtain the left coronal view with the probe marker in the cephalad direction (left). A scan was performed anterior to the spleen (Sp) to identify the gastric body (GB). Please click here to view a larger version of this figure.

Figure 8: Left upper quadrant transverse gastric body view (aka "LUQ transverse view"). To obtain the anterior transverse gastric body view, place the probe on the anterior aspect of the patient's abdomen (Left). The gastric body is visualized and, in this image, is full of liquid and solid contents and appears superficial to the splenic vessels (SV). Please click here to view a larger version of this figure.

Figure 9: Subxiphoid sagittal view showing an indeterminate segment of the stomach. Although the liver and stomach are clearly visible in the above scan, the great vessels cannot be visualized. In this case, it is necessary to increase the depth and obtain a view of the aorta to ensure that the scan is at the level of the gastric antrum. Please click here to view a larger version of this figure.

Figure 10: Subxiphoid sagittal view showing antrum containing clear fluid with air bubbles. This view shows recently ingested liquid in the antrum with air bubbles present. This speckled appearance of the liquid is referred to as a "starry night" pattern. The liver (L) is identified as the underlying pulsatile aorta (white triangles). Please click here to view a larger version of this figure.

Figure 11: Subxiphoid sagittal view showing solid content (early stage). This is the typical appearance of the antrum in 0-90 min post-prandial. The distended antrum (thin blue line) is detected inferior to the liver (L). The solid contents are noticeable as a "frosted glass" appearance (FG). Please click here to view a larger version of this figure.

Figure 12: Subxiphoid sagittal view showing solid content (late stage). Starting about 1-2 h after the ingestion of a solid meal, the appearance of solids on ultrasound evolves from the "frosted glass" finding (Figure 10) to a hyperechoic one that permits visualization of the posterior gastric wall. Please click here to view a larger version of this figure.

Discussion

As stated previously, the primary purpose of gastric ultrasound is to evaluate gastric contents and assess risk before airway management or procedural sedation. The provided protocol outlines two main methods to capture images of the gastric antrum and body, aiding in this risk assessment. Additionally, reviewing the representative results section assists gastric sonographers in developing image interpretation skills. While a comprehensive discussion of medical decision-making is beyond this protocol's scope, this manuscript will address limitations, specific clinical scenarios requiring further exploration, challenges, unanswered questions, and the minimal training level necessary for competency.

In terms of limitations, current two-dimensional methods of gastric ultrasound are inherently less precise than techniques like gastric scintigraphy or more invasive imaging, which can visualize the entire stomach volume¹⁸. However, these complex and invasive approaches are often impractical for perioperative and critically ill patients. In contrast, gastric Point-of-Care Ultrasound (POCUS) stands out due to its speed, mobility, and non-invasiveness.

Certain clinical situations pose challenges in ultrasound interpretation, such as patients with substantial hiatal hernias, prior partial gastrectomy, or those unable to assume the right lateral decubitus (RLD) position^19,20. For such cases, subxiphoid views lack validation for quantitative evaluation. In these instances, clinicians might employ subxiphoid and/or left upper quadrant (LUQ) views qualitatively to identify significant gastric distension, recognizing potential limitations in situations with abnormal gastric anatomy. For example, subxiphoid views might remain useful for patients with known hiatal hernias²¹. LUQ views have been applied to assess conditions like gastric volvulus^22,23and to diagnose gastric outlet obstruction²⁴. In such cases, the lateral coronal view could reveal an expanded gastric body with dense solid materials and gaseous air. It is crucial to identify the absence of haustra to determine whether the obstruction pertains to the gastric body rather than the distended bowels²⁵.

As with any POCUS technique, possible pitfalls may lead to misinterpretation. First, a dilated gastric body might be misdiagnosed as perisplenic free fluid or a splenic hematoma^26,27. Second, distinguishing between an air-filled colon and the stomach can be challenging. To differentiate, remember that the stomach, under ultrasound, will display a hypoechoic (dark) layer representing the muscularis propria, unlike the colon, which lacks this layer and exhibits a hyperechoic rim (Figure 4).

Despite extensive research on gastric ultrasound, certain questions remain unanswered. For instance, while the original method to quantify liquid contents was outlined with the head of the bed at 30 degrees, recent reports suggest that a 45-degree angle might enhance the qualitative assessment of the gastric antrum²⁸. Although gastric POCUS demonstrates high sensitivity and specificity in detecting gastric contents²⁹, evidence regarding whether its use reduces the risk of pulmonary aspiration is lacking.

Gaining proficiency in gastric POCUS can be relatively swift, with most practitioners able to qualitatively assess gastric contents after fewer than 50 supervised scans³⁰. However, quantitative evaluation necessitates more training and practice¹². Moreover, specific clinical contexts (as mentioned above) demand experienced clinician sonographers for accurate interpretation. This article presents two systematic and stepwise image acquisition techniques, maximizing the likelihood of obtaining interpretable results.

Materials

Name	Company	Catalog Number	Comments
High Frequency Ultrasound Probe (HFL38xp)	SonoSite (FujiFilm)	P16038
Low Frequency Ultrasound Probe (C35xp)	SonoSite (FujiFilm)	P19617
SonoSite X-porte Ultrasound	SonoSite (FujiFilm)	P19220
Ultrasound Gel	AquaSonic	PLI 01-08