Imaging Studies: What Is Their Role?

Beyond the use of gray scale and color Doppler modes, other imaging modalities may be indicated for imaging prostatitis in selected cases. Contrast-enhanced ultra sonography (CEUS) has potential in differentiating avascular abscesses from hypo vascular lesions and in identifying small abscesses not detected on conventional ultrasonographic modes. Multiparametric MR imaging allows a panoramic view of the prostate and of the surrounding tissues, which may be useful in severe infl am mation spreading outside the boundaries of the organ. T2-weighted, diffusion- weighted, and T1-weighted images with fat suppression obtained after intravenous paramagnetic contrast agent injection are of particular value. While signal intensity of the peripheral normal prostate is usually high in T2-weighted images, inhomoge neous reduction is observed in prostatitis. Moreover, enhancement of the gland increases, as well as that of surrounding tissues involved by the infl ammatory pro cess. Diffusion-weighted images provide information about motion of the water molecules, which is restricted in collections of dense fl uid such as pus. Indeed, abscesses usually present with relatively high signal intensity on T2-weighted images, but lower than water, and high signal intensity on diffusion-weighted images. Vascularization is lacking after gadolinium contrast administration. A per ilesional rim of enhancement may be observed. Air is signal void in all MR sequences.