Since ultrasound was first used to identify a renal stone as a “blip” on the monitor in 1961,¹ rapid technological development has led to improved image quality with smaller and less expensive equipment. The net result has been increased accessibility to high-quality imaging. As a noninvasive and portable imaging modality, point-of-care ultrasound (POCUS) technology enables providers to perform real-time imaging in a variety of patient settings including outpatient clinics, emergency departments (EDs), and inpatient floors (see Table). Eliminating a separate encounter for a formal radiology ultrasound during outpatient follow-up of nephrolithiasis or decreasing the wait time in the emergency department for imaging assessment can lead to fewer missed appointments and faster time to diagnosis. POCUS has grown in popularity as it allows rapid and accurate diagnostic information at the bedside. The objective of this article is to review the applications of POCUS for urologists in a variety of clinical contexts.

Diagnosis to Disposition: POCUS in the ED

For patients presenting with acute flank pain to the ED, the choice of the initial imaging modality has been a topic of ongoing debate as the harms of repeated ionizing radiation exposure must be weighed against the sensitivity and specificity of the imaging test. A large, multicenter, comparative effectiveness trial randomized patients presenting to the ED with flank pain to POCUS, radiology ultrasound, or CT for initial imaging.² Patients who underwent POCUS had shorter ED stays. Between the 3 treatment arms, there were no differences in adverse events, return ED visits, or diagnostic accuracy. Secondary analysis of these data demonstrated that ultrasound did not delay appropriate definitive stone intervention and 25% of patients were able to avoid ionizing radiation altogether in their care pathway.³ In addition, this technology has also been leveraged for rapid identification of time-sensitive diagnoses (see Table) such as testicular torsion⁴ or emphysematous pyelonephritis.⁵

Expertise with POCUS empowers providers to reach beyond simply diagnosing acute conditions to enabling procedural intervention as well. Relief of acute ureteral obstruction with a retrograde ureteral stent is most often performed in the operating room under general anesthesia. During the COVID-19 pandemic when operating room access was limited, our group was able to leverage familiarity with POCUS to perform this procedure safely at the bedside. Patients in both the ED and the inpatient floor were given oral or intravenous premedication and local urethral analgesic. Most procedures lasted less than 30 minutes and 88% of the patients had stents successfully placed. In all cases, live ultrasound was used to verify wire access and location and a postprocedure abdominal plain film confirmed stent placement.⁶ POCUS facilitates new safe and expeditious ways for physicians to bring procedures to patients.

Outpatient POCUS: Keeping the Patient in Focus

Ultrasound is often utilized in outpatient care for the management of nephrolithiasis, as it allows for the monitoring of patients during a trial of passage, postoperative imaging, and long-term surveillance. Typically, such follow-up imaging is obtained before the clinic visit and performed at a separate encounter by a trained sonographer. These additional appointments lead to missed visits or late cancellations. A study by colleagues at the University of Washington showed that in-office ultrasound led to a change in management in 33% of visits based on the information. In the study period of over 31 days, 34 patients cancelled their visits as planned imaging had not been obtained.⁷ Another study in pediatric urology evaluating POCUS for postoperative imaging after pyeloplasty showed no difference in detecting changes in hydronephrosis when comparing POCUS to a radiology-performed ultrasound.⁸ The authors estimated 2 hours saved per health care encounter and $83,000 less charges to payers. The portability and flexibility of POCUS lends itself to a wide range of use cases in the outpatient arena (see Table).

Not Just a Bunch of Hocus POCUS: The Use of Ultrasound in Resident Education

Ultrasound technology is becoming more accessible and common in medical training. Residents are gaining earlier exposure to the technology and developing greater proficiency in its use. During internship, many trainees may first be exposed to ultrasound use in central or arterial line placement. Then during dedicated urology training, residents often build on this initial experience. For example, urology residents at the University of California, San Francisco, have access to the Clarius handheld ultrasound that connects via Bluetooth to their cellular devices. The team has used this during rounds or on-call to assess situations such as evaluating clot burden during a bedside clot evacuation for gross hematuria, placement of suprapubic catheters, or monitoring of hydronephrosis to inform decisions for urinary diversion.

There has been growing interest in formally introducing this technology to our trainees. The McMaster University urology program published their experience with a resident-focused introductory program on POCUS and demonstrated that a short, inexpensive, and guidelines-based course led to significant improvements in theoretical knowledge and skill confidence.⁹ Another group described their experience with integrating a POCUS curriculum as early as the first year of medical school.¹⁰ Early and standardized exposure to and training in POCUS empowers trainees not only during residency but has an impact on graduates as they move into practice. In the previously described manuscript by Villanueva et al, exposure to POCUS in residency allowed 3 urologists to use POCUS in over 50% of visits while the urologist with no exposure during training utilized POCUS in only 5%.⁸

POCUS has become an increasingly important tool in urology, providing quick and accurate diagnostic information at the bedside in a range of clinical settings. The use of POCUS has been shown to be feasible and effective in emergency departments, outpatient clinics, and in resident education, improving patient care while reducing the need for additional imaging procedures and delays in treatment. As ultrasound technology continues to advance and become more accessible, its use in urology and urological training is likely to continue to grow and play an even more significant role in patient care.