June 2014

 

To Image or Not to Image—That Is the Question with Hematuria Evaluation  

How is the ever-growing importance of controlling costs influencing decisions about how or whether to include imaging in evaluating patients with hematuria?

Cost control plays a central role in imaging decisionmaking. Cost constraints and the trend toward quality over quantity are changing the role of imaging in the evaluation of hematuria. This trend will require that the radiologist functions more as a specialty consultant rather than a high-volume practitioner. Cost containment will require radiologists to actively participate in development of rational, consensus-based clinical pathways that are also cost effective. In the future, imaging will likely not be one of the starting points in the workup of a patient with hematuria. Rather, high-quality imaging will play an important role in the hematuria pathway after nephrologic causes of hematuria are excluded.

Several organizations have issued guidelines for imaging patients with unexplained urologic causes of hematuria. Are there deficiencies in the guidelines?

The main deficiency in the current literature and among the societal guidelines issued by various clinical specialties is the lack of consensus. As the imaging reference has evolved over time, diverse practice patterns and recommendations have developed. Another source of deficiency in many guidelines is the lack of accountability for the patient’s risk profile and pretest probability of malignancy; there is a critical knowledge gap in how to stratify patient subgroups with microscopic hematuria and integrate the imaging workup. This gap has led to unpredictable and, arguably, unnecessary ordering of extensive and expensive imaging examinations.

What are the risk factors for urinary tract malignancies?

There are many. Some of the more common factors are smoking, race/ethnicity, advancing age, male gender, genetics, obesity, and workplace exposures (chemicals/fumes for some workers in the paint, leather, textile, printing, and hairdressing industries).

How does age play a role in determining how to image patients with hematuria?

Age is a key factor when selecting patients for imaging of hematuria. Elderly patients with macroscopic hematuria have a significantly higher risk of urinary tract malignancy, so they merit a comprehensive imaging workup with CT urography. For younger patients, the risk of malignancy in the setting of asymptomatic hematuria is extremely low; ergo, a much more conservative approach in which extensive imaging is omitted, delayed, or tailored is often appropriate.

What factors should be considered when determining the type of imaging used in evaluating hematuria?

The primary factors to consider are the patient’s symptoms, demographics, risk profile, and pretest probability of urinary tract malignancy. Some examples include the patient’s age, known age-independent risk factors for malignancy, such as family history or industrial exposures, and the presence of macroscopic versus microscopic hematuria. It is important to control radiation exposure in younger patients; if CT is considered in a young patient with a low pretest probability of urinary tract malignancy, a single-phase, unenhanced CT may be as effective as a multiphase CT urography study.