(a)
(b)
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Figure 3: The value of the endorectal coil. A very subtle area of low signal on T2-weighted imaging (a) is associated with blurring of the “capsule” (thick arrow), suggesting capsular involvement. This patient underwent imaging without the coil immediately afterwards (b) where the low signal mass (thick arrow) is indistinct, as is the dark signal line that should signify the “capsule.” As the rectum is distended (arrowhead), this may result from susceptibility artifact. Restricted diffusion on the apparent diffusion coefficient (ADC) map (c) and focal increased perfusion on the dynamic contrast-enhanced (DCE) perfusion map confirm the location of cancer in this case.