For a patient with isolated non-visible hematuria and normal urine analysis, what is the most appropriate next investigation?

In the context of isolated non-visible hematuria with a normal urine analysis, the most appropriate next step in investigation is CT urography. This imaging modality is particularly useful for evaluating potential causes of hematuria such as urinary tract stones, tumors, or other abnormalities of the urinary system, including the kidneys, ureters, and bladder.

CT urography provides detailed cross-sectional images that can help identify lesions or structural issues that may not be detectable through standard ultrasound or X-rays. Because isolated non-visible hematuria can sometimes be indicative of serious underlying conditions such as malignancies or polycystic kidney disease, CT urography serves as an effective first-line imaging study to rule out significant pathology.

Other options like anti-neutrophil cytoplasmic antibodies are more relevant for specific autoimmune conditions and wouldn’t directly investigate the cause of hematuria. Cystoscopy, while useful for evaluating bladder pathology directly, is more invasive and is typically recommended when there is either visible hematuria or a specific indication from prior imaging. A renal biopsy is usually not warranted at this stage without clear signs of renal pathology, as it is an invasive procedure focused on kidney tissue examination rather than a direct response to hematuria. Therefore, CT