Genitourinary Conditions in the Emergency Setting
Jennifer W. Uyeda
Given the widespread use of imaging for the diagnosis of clinical entities seen in the emergency department, it is important that radiologists stay familiar with the various conditions of the urinary system.
In the June issue of AJR, a team of radiologists at Brigham and Women's Hospital uses a case-based approach to summarize the role of imaging in diagnosing acute and emergent genitourinary conditions. InBrief talked with corresponding author Jennifer W. Uyeda about the research.
Why did the research team decide to conduct this review?
The emergency radiology section at Brigham and Women’s Hospital commonly encounters a wide range of genitourinary abnormalities, some of which are emergency conditions requiring accurate and rapid diagnosis to ensure timely treatment. Radiologists and trainees alike must be familiar with the imaging appearances of both common and rare abnormalities in addition to pertinent differential diagnoses.
How important is accurate and rapid diagnosis of emergency genitourinary conditions?
Not all pathologic conditions affecting the genitourinary tract require imaging for diagnosis or treatment; however, certain conditions, including emphysematous pyelonephritis, tuboovarian abscess, and testicular torsion or rupture, must be rapidly diagnosed and treated to minimize morbidity and mortality. Imaging can also help guide surgical planning because the findings can be used to localize and characterize injuries, as is the case with penile fractures and intraperitoneal bladder ruptures.
Strong familiarity with the various conditions of the urinary system is essential to choosing the appropriate imaging modality in an emergency. Are there conditions for which a particular imaging modality is considerably more—or less—sensitive?
For the evaluation of acute and emergency genitourinary disorders, the imaging modality of choice typically is CT; however, there are conditions for which sonography is more sensitive. For example, ovarian and testicular abnormalities are best evaluated with ultrasound (although equivocal or complicated cases, including penile fractures and tuboovarian abscesses, can be characterized with MRI). CT is more sensitive than ultrasound for diagnosing pyelonephritis, detecting the presence and grading the severity of hydronephrosis, evaluating for the presence and type of bladder rupture, and detecting retroperitoneal hematomas.
What are some of the potential consequences of using a less optimal imaging modality?
Using an imaging modality that is less sensitive for a particular condition can delay diagnosis—or even result in misdiagnosis. For example, hydronephrosis can be readily detected with sonography, but the diagnosis of pyelonephritis with ultrasound is difficult. Some conditions can be missed entirely if the inappropriate imaging modality is used.
Compared with CT cystography, ultrasound is suboptimal for the evaluation of bladder rupture. But ultrasound is the optimal imaging modality for testicular and ovarian pathologic conditions that can be missed with CT, including testicular and ovarian torsion and ectopic pregnancy. Strong familiarity with the appropriate imaging modality in the acute or emergency setting is also essential for accurate and timely diagnosis of many pathologic conditions.
What are some of the rare conditions of which radiologists in the emergency department need to be aware?
Fortunately, penile fractures are fairly rare; nevertheless, familiarity with the normal penile anatomy—particularly the tunica albuginea on both ultrasound and MRI—is essential to accurately detect focal tunica albuginea lacerations. MRI readily depicts complicated penile fractures and can assist in accurate localization and characterization of tunica albuginea lacerations to aid in surgical planning. Radiologists’ familiarity with the appearance of emphysematous pyelonephritis on ultrasound, CT, and MRI is imperative.
If you had to specify three key points in the article that radiologists in the emergency department should retain, what would they be?
First, familiarity with the appearance of the most acute pathologic conditions on ultrasound, CT, and MRI is imperative to minimize morbidity and mortality.
Second, CT typically is the imaging modality of choice in the evaluation of acute and emergency genitourinary disorders, but ultrasound can be helpful in certain diagnoses, so knowledge of these conditions is important.
Finally, because of its improved soft-tissue characterization and higher resolution, MRI is used as a problem-solving tool, and selective use of MRI can improve diagnosis and result in favorable clinical outcomes.