Comparison of [۹۹mTc]Tc-phytate and [۹۹mTc]Tc-antimony sulfide colloid in a patient with non-parasitic chyluria

Chyluria, the passage of chyle into urine due to lymphatic–urinary fistulas, may arise from parasitic or non-parasitic causes. In non-endemic regions, trauma, surgery, infection, or malignancy are more common etiologies. Lymphoscintigraphy is a valuable noninvasive tool for detecting lymphatic leaks; however, the choice of radiotracer significantly affects diagnostic accuracy. We report the case of a ۳۹-year-old man with milky urine following pelvic trauma. Initial lymphoscintigraphy using [۹۹mTc]Tc-phytate showed bladder activity, but physiological tracer excretion could not be excluded. Repeat imaging with [۹۹mTc]Tc-antimony sulfide colloid demonstrated no early urinary activity; however, after fatty meal provocation and delayed scanning, clear tracer accumulation in the bladder was visualized and confirmed by SPECT/CT, establishing the diagnosis of chyluria. Further evaluation revealed intestinal lymphangiectasia, suggesting an underlying lymphatic abnormality potentially exacerbated by trauma. This case emphasizes the importance of selecting specific radiotracers and incorporating provocation with delayed imaging to improve the sensitivity and specificity of chyluria assessment.

کلیدواژه ها:

Lymphoscintigraphy ، [۹۹mTc]Tc-phytate ، [۹۹mTc]Tc-antimony sulfide colloid ، Nuclear medicine