SUBJECTS AND METHODS. Twenty patients due for prostatectomy underwent endorectal MRI at 1.5 T. Transverse T2-weighted, diffusion-weighted, 2D chemical shift, and dynamic contrast-enhanced images were acquired. After prostatectomy, the gland was sectioned transversely. Fresh slices and stained whole-mount sections with histologically defined tumor outlines were photographed. The tumor outlines were mapped onto images, and the apparent diffusion coefficient (ADC), choline-to-citrate (Cho/cit) ratio, and vascularity of the histologically defined tumor, normal peripheral zone, and central gland were quantitatively measured. Area under the receiver operating characteristics (ROC) curve (A_z) was used to determine the sensitivity and specificity of parameter combinations in cancer detection.

RESULTS. In tumor regions larger than 1 cm², the Cho/cit ratio was higher in tumor than in nontumor tissue (p < 0.001), in the peripheral zone alone (p = 0.007), and in the central gland alone (p = 0.005). ADC was lower and tumor vascularity greater in tumor than in nontumor tissue (ADC, p = 0.003; initial area under the gadolinium plasma concentration–time curve [initial gadolinium AUC], p = 0.012; forward rate constant [K^trans], p = 0.011; return rate constant [k_ep], p = 0.036). No single parameter had a significantly greater A_z (ADC, 0.71; Cho/cit ratio, 0.79; initial gadolinium AUC, 0.60; K^trans, 0.62; k_ep, 0.65). Pairs of parameters, however, did increase A_z: ADC and initial gadolinium AUC (A_z = 0.94) versus ADC (p = 0.001) and initial gadolinium AUC (p < 0.001); ADC and Cho/cit ratio (A_z = 0.94) versus ADC (p = 0.001) and Cho/cit ratio (not significant); and Cho/cit ratio and initial gadolinium AUC (A_z = 0.88) versus Cho/cit ratio (not significant) and initial gadolinium AUC (p < 0.001). All three functional techniques together had an A_z of 0.95, showing no further improvement.

CONCLUSION. The combination of two functional parameters is associated with significant improvement in prostate cancer detection over use of any parameter alone. Use of a third parameter does not increase the rate of detection.

CONCLUSION. Local evaluation of the primary tumor in patients with transitional cell carcinoma on PET is often limited by the obscuring effect of excreted FDG, but assessment of metabolic activity may still be possible through close correlation with CT images. PET/CT may also be helpful in the detection of disease outside the bladder at nodal or more distant sites and in the assessment of recurrent disease.

MATERIALS AND METHODS. A retrospective review of all intravascular doses of low-osmolar iodinated and gadolinium contrast materials administered from 2002 through 2006 was conducted. Adverse effects were identified through the use of radiologist and nurse event recording. Adverse effects were examined for type and severity of reaction, treatment required, and outcome.

RESULTS. A total of 456,930 contrast doses (298,491 low-osmolar iodinated, 158,439 gadolinium) were administered over the study period. A total of 522 cases of adverse effects (0.11% of total) were identified (458 low-osmolar iodinated, 64 gadolinium). The most common adverse effects were hives (274, 52.5%) and nausea (92, 17.6%). Of all adverse effects, 79 of low-osmolar iodinated and 15 of gadolinium contrast material necessitated treatment. Most treatments were performed in the radiology department alone. Only 16 cases of adverse effects necessitated transfer for further observation or treatment. Epinephrine was used to manage an adverse effect in nine instances. Thirty-two of the adverse effects of low-osmolar iodinated contrast material (6.9%) occurred in patients with a history of allergy who received premedication. Only two of these premedication reactions necessitated transfer to the emergency department. The one death in the study period occurred after administration of low-osmolar iodinated contrast material. The patient had no symptoms during the contrast administration or imaging but died suddenly within 30 minutes of receiving the dose.

CONCLUSION. Both iodinated and gadolinium contrast agents are associated with a very low rate of adverse effects. Most adverse effects are mild and can be managed in the radiology department. Transfer for additional treatment or observation is rarely needed.

CONCLUSION. Proper characterization is essential to ensure that life-threatening sequelae from Addisonian crisis are averted in infection and hemorrhage, or to identify "leave-alone" lesions such as pseudocyst and chronic calcification.