Detection of Hepatic Metastasis in Colorectal Cancer: A Comparative Case Report of 18F-FDG PET-CT and Diffusion-Weighted MRI with a b Value of 1000

Detection of hepatic metastasis from colorectal cancer remains a clinical challenge. In this case report, we present a 66-year-old male patient with a rectal carcinoma who underwent ¹⁸F-FDG PET-CT for staging, which revealed one hepatic metastasis. Abdominal magnetic resonance imaging (MRI) with diffusion-weighted sequence with a b value of 1000 was performed, which identified a second metastasis of the liver.

Teaching Point: This case report illustrates that, in some patients, diffusion-weighted MRI with a b value of 1000 might be a more sensitive technique for detecting small hepatic metastases than ¹⁸F-FDG PET-CT.