Click on image to view larger version.
FIGURE 4. Pattern 4: incongruent findings of abnormal 18F-FDG uptake indicating presence of active cancer with no mass on CT. A 59-y-old male patient, 4 y after abdominoperineal resection for well-differentiated cancer of rectum, stage C2, and elevated levels of tumor serum markers. 18F-FDG images (center) show abnormal uptake localized by hybrid TET images (right) to prostate, which is of normal size on CT image (left). Studies are presented in transaxial (top row), coronal (middle row), and sagittal (bottom row) planes. Red markers are used to allow for exact localization of lesion on CT. Biopsy was guided by precise localization provided by hybrid imaging. It revealed metastasis from rectal cancer to prostate, detected by abnormal 18F-FDG uptake but not by CT.
