From the Guidelines
CT Urography (CTU) is the best imaging test for microscopic haematuria, excluding cystoscopy.
Key Points
- CTU has been shown to be the imaging study of choice for the evaluation of microhematuria because it can evaluate both nephrogenic and urogenic causes of hematuria 1.
- CTU has a high sensitivity and specificity for the detection of urothelial malignancy, with a pooled sensitivity of 96% and pooled specificity of 99% 1.
- CTU is superior to Intravenous Urography (IVU) for the detection of upper tract lesions, with an accuracy of 99.6% compared to 84.9% for IVU 1.
- The American College of Radiology and the American Urological Association recommend CTU as the imaging procedure of choice for the evaluation of microhematuria 2, 3.
- CTU is particularly useful for patients with risk factors for urinary tract cancer, and is usually appropriate for the initial imaging of microhematuria in patients without certain contraindications such as recent vigorous exercise, presence of infection or viral illness, or renal parenchymal disease 3.
- While ultrasound (US) may be adequate for initial evaluation of microhematuria in some cases, such as in pregnant patients, CTU remains the preferred imaging modality for most patients 4, 3.
From the Research
Imaging Tests for Microscopic Haematuria
The best imaging test for microscopic haematuria, excluding cystoscopy, is a topic of discussion among various studies.
- According to 5, ultrasonography (US) detects more tumors than intravenous urography (IVU) at one-third of the cost and is also associated with fewer false results.
- Computed tomography (CT) has a mean incremental cost-effectiveness ratio of £9939 in comparison with the next best option, US 5.
- A study by 6 suggests that IVU is a useful secondary radiographic study when microhematuria has persisted for 3 months after the initial workup with renal ultrasound (US) and cystoscopy was negative.
- Another study by 7 highlights the pivotal role of multidetector computed tomography urography (MDCTU) in the imaging of the patient with haematuria, discussing issues specific to this modality including protocol design, imaging of the urothelium, and radiation dose.
Comparison of Imaging Modalities
The choice of imaging modality depends on individual patient factors such as age, risk factors for malignancy, renal function, and history of calculus disease 7.
- Ultrasonography (US) is a useful initial imaging test due to its low cost and few false results 5.
- Computed tomography (CT) is a more sensitive test but has a higher cost and radiation dose 5, 7.
- Intravenous urography (IVU) is a secondary radiographic study that can be used when microhematuria persists after initial workup with US and cystoscopy 6.
Guidelines and Recommendations
Various guidelines and recommendations are available for the evaluation and management of asymptomatic microscopic haematuria (AMH) 8.
- The American Urological Association, Canadian Urological Association, and other organizations recommend evaluation for AMH in the absence of potential benign aetiologies, including cystoscopy and upper urinary tract imaging 8.
- The optimal imaging method (computed tomography vs ultrasonography) varies among guidelines, and there is no universal agreement on the best approach 8.