Abdominal pain is a leading cause for visits to the emergency department (ED). The evaluation of the abdomen frequently utilizes many resources, not the least of which is the time often invested in serial exams, use of consultants, and imaging procedures. Focused bedside ultrasound offers a valuable adjunct for the assessment of abdominal pain. With even a moderate amount of training and limited experience, emergency physicians can obtain sufficient skill to incorporate right upper quadrant (RUQ) ultrasound into their bedside exams and clinical decisions (1, 2, 3, 4, 5, 6). Most studies can be completed in <10 minutes (5). The current literature verifies that emergency ultrasound of the RUQ is accurate, improves time to diagnosis and treatment, decreases ED length of stay, and improves patient satisfaction (7, 8, 9). Ultrasound of the RUQ is included in the list of recommended applications for emergency ultrasound and is part of the model ultrasound curriculum of emergency medicine residency training programs (10).

RUQ ultrasound is useful in assessing three common problems:

There are four common practical applications for bedside ultrasound of the RUQ, including the detection of:

Ultrasound can also potentially help in the search for a focal source of infection in patients who are septic, those with altered mental status and unreliable exams, and in the elderly or immunocompromised who may be less likely to have focal findings (11).

The liver is the major acoustic window to the abdomen. Familiarity with the liver and its surrounding structures will open up a variety of applications for abdominal scanning beyond those listed here. As clinicians become proficient in RUQ scans, they will likely become more confident in the Focused Assessment by Sonography for Trauma (FAST) exam (to assess for free fluid in Morison’s pouch) and in the scan of the proximal abdominal aorta (to detect aneurysms and dissections). Although RUQ ultrasound is primarily focused on the liver, gallbladder, and biliary tree, it may incidentally reveal pathology in adjacent areas in the right kidney, pleural space, pancreas, and aorta.

The liver, gallbladder, and biliary tree can be imaged from a number of approaches (subcostal, intercostal, and flank) with the patient in a variety of positions (supine, semirecumbent, erect, left lateral decubitus, and prone). The optimal technique will vary based on differences in anatomy, body habitus, and bowel gas patterns. Ideally, the sonographer should begin with a few standard approaches, modified and guided by both external and internal landmarks (Fig. 9.1).

The subcostal approach is the most commonly used initial approach to imaging the gallbladder. Begin with the patient supine, and place the transducer in the midline at the epigastrium with the transducer oriented in the sagittal plane (Fig. 9.1A). If there is a large left hepatic lobe, the liver may be easily seen in this position. Leaving the transducer in the midline, tilt the transducer to project the sound wave toward the patient’s right side. In some cases, this will be sufficient to localize the gallbladder. If it is not seen, move the transducer down the costal margin while projecting it cephalad under the rib margin to scan through the dome of the liver. In many patients, the liver is mostly intrathoracic. In these patients, an improved image can be obtained by placing the transducer between the ribs (intercostal approach) (Fig. 9.1B). Alternatively, the patient can be positioned to bring the liver down below the costal margin. Have patients sit erect or semirecumbent, and instruct them to breathe deeply with their “belly out.” As the liver descends, the liver and gallbladder may be more easily imaged. If these maneuvers fail, move the patient to a left lateral decubitus position. This position brings the liver and gallbladder more toward the midline and closer to the transducer. Scan again from the subcostal approach, then continue to move the transducer along the costal margin toward the right flank. If the anterior subcostal approach is unsuccessful, leave the patient in a left lateral decubitus position, and scan through the right flank to identify the right kidney and Morison’s pouch (Fig. 9.1C). Once the right kidney is in view, the transducer should be angled slightly cephalad and anterior. The fundus of the gallbladder lies in close proximity to the right kidney and will often pop into view with this maneuver. Occasionally, it is useful to roll the patient from a left lateral decubitus position into a nearly prone position and scan from a subcostal approach. This position brings the gallbladder anterior. If heavy shadowing is seen from the gallbladder fossa, moving the patient prone may help the stones fall forward and make the echogenic stones more visible themselves, helping distinguish the shadows of a gallbladder packed with stones from artifact created by bowel gas (12).

If these external landmarks do not produce a good image, focus on obtaining the best possible acoustic window of the liver and follow internal landmarks. The portal triad and main lobar fissure (MLF) are useful landmarks that can be used to locate the gallbladder fossa. If the portal triad is used to define the center of a clock face, the gallbladder is usually found around 2 o’clock. The MLF can be seen as an
echogenic line joining the portal triad to the gallbladder. (See section on Anatomy.)

Regardless of how the image is obtained, once the gallbladder is identified, the entire organ should be scanned to fully visualize it. Gently rocking the transducer right and left, then rotating it 90 degrees to view both the long and short axis will produce a three-dimensional perspective. It is often necessary to manipulate the transducer to fully define the anatomy and pick up stones that may be obscured by the twists and turns common to many gallbladders.

In general, the best ultrasound images are obtained when sound waves are directed perpendicular to the organ of interest in as direct a path as possible. Unfortunately, this approach may not always work for the gallbladder. From patient-to-patient there is considerable variation in the location and orientation of the gallbladder, and there are a number of acoustic barriers. For example, the transverse colon often rests immediately adjacent to the gallbladder, and the duodenum sweeps along its medial margin (Fig. 9.2). If the sound waves encounter bowel gas from either, shadowing will obscure the image. Most of the maneuvers described here are simply attempts to direct the ultrasound beam around these obstacles.

There are no consistent external landmarks or transducer positions that can adequately guide the emergency sonographer to reliably visualize the gallbladder in all patients. These guides are a starting point. Ideally, sonographers should use a systematic approach for scanning and modify their approach based on their experience and success.

The primary indication for a bedside RUQ ultrasound is to detect gallbladder disease as a potential source of pain. The novice may be tempted to focus solely on identifying the gallbladder and then be satisfied once its visualized. However, the RUQ is an anatomically complex area traversed by a number of vascular and ductal structures, most of which are well visualized by ultrasound. Even if the sonographer does not initially desire to identify this anatomy, the busy network of vessels and structures in the area will likely be distracting, if not confusing. Some sonographers have found that this region is more difficult than many applications of ED bedside ultrasound, but once mastered, their ability to explore the abdomen and their confidence in their results are greatly enhanced. A thorough and methodical review of this anatomy will improve the diagnostic utility of RUQ ultrasound.