Prostate
The normal prostate typically demonstrates little or no FDG uptake.
Mild diffuse prostate uptake is considered normal.
Moderate or intense diffuse uptake typically reflects prostatitis.
Although even focal FDG uptake in the prostate is often normal, correlation with PSA levels is advised, especially if the uptake is located in the peripheral zone (site of 70% of prostate cancers).
Uptake centrally in the gland typically represents normal hypermetabolic urine in the prostatic urethra.
Increased Incidence of Malignancy:
- Uptake associated with a visible lesion or area of focal calcification on the CT exam.
- Focal uptake located in the peripheral zone.
- The presence of associated hypermetabolic lymph nodes or bone lesions.
Case 1
Case 1 (Image 2)
Normal mild diffuse uptake of FDG throughout a normal prostate gland.
Case 1 (Image 3)
Enlarged prostate gland. Normal PET appearance, with only minimal diffuse uptake.
Case 2
Case 2 (Image 2)
Axial images demonstrate an intense hypermetabolic focus centrally within the prostate gland. CT images demonstrate an extremely subtle hypodensity in this location. This represents normal hypermetabolic urine within the prostatic urethra (no history of TURP in this patient).
Case 3
Case 3 (Image 2)
Axial images demonstrate an intense hypermetabolic focus centrally within the prostate gland. CT images demonstrate an associated hypodensity in this location. This represents normal hypermetabolic urine within a TURP defect.
Case 4
Case 4 (Image 2)
Axial images demonstrate diffuse increased metabolic activity throughout the prostate gland, non-focal (the CT images are unremarkable). While this can represent normal physiologic uptake, this also can be seen with prostatitis, which fit the clinical presentation of this patient (who was being imaged to evaluate his lung cancer).
Case 5
Case 5 (Image 2)
Axial images demonstrate the hypermetabolic focus to be located within the peripheral zone of the prostate gland. Although the non-contrast CT images are unremarkable, the focal nature of this uptake and its location within the peripheral zone should always raise a suspicion for malignancy (biopsy-proven).