What imaging is required for a patient with hematuria (blood in urine)?

From the Guidelines

For a patient with hematuria, the recommended imaging typically includes a CT urogram (CTU) without and with IV contrast for the initial imaging of gross hematuria or microhematuria in patients with risk factors, as stated in the most recent guidelines 1. This approach is based on the American College of Radiology's (ACR) Appropriateness Criteria for hematuria, which provides a comprehensive framework for evaluating patients with hematuria. The guidelines recommend the following imaging modalities:

• CT abdomen and pelvis without IV contrast for the initial imaging of microhematuria in patients with no risk factors or history of recent vigorous exercise, or presence of infection, viral illness, or present or recent menstruation.
• CTU without and with IV contrast for the initial imaging of microhematuria in patients with risk factors.
• US kidneys and bladder retroperitoneal for the initial imaging of microhematuria in pregnant patients.
• CTU without and with IV contrast or MRU without and with IV contrast for the initial imaging of gross hematuria. It is essential to note that cystoscopy is also a crucial component of the evaluation, especially in adults over 35 years with risk factors for bladder cancer, as recommended by the American Urological Association (AUA) guidelines 1. The choice of imaging should be tailored to the patient's clinical presentation, risk factors, and the degree of hematuria, with more comprehensive imaging for those with gross hematuria or significant risk factors for urological malignancies. Key points to consider when evaluating a patient with hematuria include:
• The degree of hematuria (microscopic or gross)
• The presence of risk factors for urological malignancies
• The patient's clinical presentation and medical history
• The need for cystoscopy and upper urinary tract imaging By following these guidelines and considering the individual patient's needs, clinicians can provide optimal care and minimize the risk of morbidity, mortality, and decreased quality of life.

From the Research

Imaging for Hematuria

• For patients with hematuria, non-contrast computed tomography (CT) scan is considered the gold standard diagnostic tool 2.
• The sensitivity, specificity, positive predictive value, and negative predictive value for microhematuria in diagnosing renal and ureteral stones are 77%, 33%, 67%, and 45%, respectively 2.
• Microhematuria is more common in patients with ureteral stones, with a sensitivity of 85% compared to patients with renal stones, which has a sensitivity of 55% 2.

CT Protocols for Hematuria

• Most institutions use 3-6 phase CT urography protocols, which are associated with higher radiation doses compared to 2-phase protocols 3.
• The median dose-length product (DLP) for urinary stones CT is significantly lower than the median DLP for other CT protocols 3.
• Few institutions use low-dose CT for urinary stones, resulting in substantial variations in CT urography and routine abdomen-pelvis CT protocols 3.

Diagnostic Approach

• For patients over 40 with microscopic hematuria, a non-contrast computed tomography or ultrasound study should be performed 4.
• If gross hematuria is observed, cystoscopy should be added to the diagnostic approach 4.
• For elderly patients, pre- and post-contrast computed tomography scans and cystoscopy should be carried out 4.

Irrelevant Studies

• Studies 5 and 6 are not relevant to the topic of imaging for hematuria, as they discuss the uptake of choline by Streptococcus pneumoniae and the determinants of colon carcinoembryonic antigen, respectively.