• Benign Lesions
• Malignant lesions
  • Hepatucellolar carcinoma (HCC)
  • Metastatic liver tumor
  • Cholangiocellular carcinoma
  • Clinical utility

Metastatic liver tumor

Metastatic liver tumor also constitutes a common malignancy. It was shown that 25% to 50% of patients with malignancy have liver metastases at autopsy. The most common primary malignancy site is the colon. Other frequent primary sites include the breast, pancreas, stomach, and ovary. Metastases may be present as either solitary or multiple hepatic masses or as a diffuse distortion of the hepatic parenchymal architecture. They can vary in size, consistency, uniformity of growth, stromal response as well as in vascularity, and they can be infiltrative or expansive in nature. Usually, the surgical approach is determined by what the surgeon finds during feeling the liver in the operating room and using intra-operative ultrasound. The number of tumors as well as their size and location will determine whether surgery will help. Hepatic mestastases, which are frequently <1cm in size, are found in 24% to 36% of all patients who die of malignancy. In order to prevent unnecessary surgeries, as well as enable less stress for patients, precise pre-operative imaging-techniques are desired.

MRI appearance of a metastatic liver tumor without (pre-contrast) and with Primovist^®

Liver metastases usually appear as hypointense (dark areas) lesions on unenhanced T1-weighted images and as moderately hyperintense (bright areas) masses on T2-weighted images (left-hand-side). Another facultative characteristic of metastases of the liver is the difference in signal characteristics between the central necrotic and the peripheral portion of the masses, which is a strong indicator of malignancy.

During dynamic imaging, signal characteristics depend on the lesion vascularization (mostly hypovascularized). In the liver-specific phase (after 20min) metastases show no liver-specific uptake and appear hypointense (dark areas) in T1-weighted sequences (right-hand-side).

Differences between an MRI with extracellular contrast media (ECCM) and with Primovist^®

Benefits of Primovist^® in comparison with extracellular contrast media (ECCM) are improved lesion detection and improved lesion characterization (additional information from the liver-specific phase). On the other hand both provide Information from the dynamic phase (lesion perfusion) and examination time and assessment of hepatic vasculature. An advantage regarding ECCM in contrast to Primovist^® is the higher dose which leads to higher vascular enhancement in the dynamic phase.

Metastatic liver tumor

Therapy

Surgical resection provides the greatest potential for cure in patients with liver metastasis but can only be offered to a small number of patients (5 %–20 %). No adjuvant treatment has yet demonstrated effectiveness in increasing the survival rate following radical surgery. For cases involving unresectable disease, several treatments have been tested in the clinical settings. Both systemic and loco-regional chemotherapy may be useful in the neoadjuvant setting. They decrease metastasis mass, thus increasing the resectability of liver metastases initially not amenable to surgical resection. In selected patients, image-guided radio frequency ablation (RFA) takes over the role as a curative treatment option, especially in patients who are technically not eligible for surgery.