Figure 4

¹⁸F-FDG PET/CT and contrast-enhanced MRI (CEMRI) scans of a 59-year-old man with clear cell carcinoma of the left kidney associated with a level II venous tumour thrombus (VTT). The VTT invaded the venous wall and was graded as level II by both PET/CT and CEMRI. The site of diffusely increased FDG uptake (SUVmax 4.3) on a PET maximum intensity projection image is the primary tumour (blue arrow) (a). The site of pathologically increased FDG uptake (SUVmax 4.5) on the PET image from the left renal vein to the inferior vena cava is the VTT (red arrow) (a). Some bone metastases in the thoracic vertebrae and a left rib showed increased focal FDG uptake (yellow arrow) (a) with lytic lesions on selected axial CT slices (yellow arrow) (b,c). The VTT did not show homogeneous enhancement and completely occluded the lumen of the inferior vena cava on coronal CEMRI (red arrow) (d). The primary tumour showed heterogeneous enhancement (blue arrow) (d).