36 CHAPTER 1  Evaluation of the Urologic Patient

A B

C D

FIG. 1.19  A 50-year-old man with a left side pheochromocytoma and select images from a 1.5T magnetic resonance imaging. (A) Heavily weighted T2 single-shot fast spin echo with an isointense signal (not bright). (B) Moderately weighted T2 fatsuppressed fast recovery fast spin echo with hyperintense signal (bright). (C) T1weighted precontrast images. (D) T1-weighted postcontrast images with marked early enhancement.

Prostate MRI. Includes anatomic (T1and T2-weighted imaged) and functional imaging techniques (diffusion-weighted imaging

[DWI] with apparent diffusion coefficient [ADC] maps, DCE se- quences). Initial T1-weighted sequences are obtained to determine if hemorrhage is present within the prostate and, if present, may limit the diagnostic interpretation of the study. T2-weighted sequences of the prostate provide anatomic information and should include a triplanar (axial, coronal, and sagittal) or comparable sequence (Fig. 1.20). These images provide a detailed anatomic assessment of the gland.

Nuclear Medicine in Urology

Nuclear imaging uses agents labeled with radionuclides to characterize molecular processes within cells. Radiotracers are administered and emit radioactivity that can be detected by an external sensor unit, formatted as an image.

Whole-Body Bone Scan. Skeletal scintigraphy is the most sensitive method for detecting bone metastasis. A “positive” bone scan

37