MDCT cystography using vaginal tampon for imaging lower urogenital tract fistulas: two case reports

Multidetector CT (MDCT) cystography combines the established technique of excretory cystography with the high spatial resolution of MDCT. MDCT cystography with the use of vaginal tampon helps in increasing the sensitivity and specificity of detecting the presence or absence of urogenital fistulas. Vaginal tampons act as both negative and positive contrast agents. Until recently, urogenital fistulas were investigated by excretory urography/intravenous urography, retrograde ureterography, or retrograde voiding cystography/micturating urography. Scintigraphy with ^99mTc diethylenetriaminepentaacetic acid has also been used to help elucidate these pathologic abnormalities. All these modalities are useful in the detection of obvious fistulous tracts but are deficient in providing anatomic detail and have a low specificity.