The purpose of this study is to investigate safety and efficacy of intravenously injected 0.4% 13-C-Methacetin solution for the determination of liver function with the LiMAx-test on patients with partial liver resection. The LiMAx-test is compared with an untreated control group and post-surgical management of both groups is investigated.

Inclusion Criteria:

• male or female patients of 18 years or older which are able to give informed consent with indication for surgical partial liver resection according to OPS code 5-502; this includes benign and malign tumors.
• patients with pre-surgical thin-layer CT or MRT of the liver not older than 6 weeks or patients where a pre-surgical thin-layer CT or MRT of the liver is planned before surgery.
• written informed consent

Exclusion Criteria:

at screening:

• anamnestic known hypersensitivity against one of the study drugs, their ingredients or drugs with chemically similar structure (in particular paracetamol)
• participation in another clinical trials within 4 weeks before inclusion
• patients with previous liver surgery (OPS-Code 5-502), including biliodigestive anastomosis, excluding cholecystectomy.
• patients which underwent interventions such as radiofrequency ablation, biopsies or smaller surgeries within 6 weeks before inclusion
• patients anticipated for biliodigestive anastomosis and/or suffering from a Klatskin-tumor
• patients with a ASA (American Society of Anesthesiologists) classification >3
• patients anticipated for laparoscopic partial liver resection
• patients which are intended to be simultaneously treated with an interventional technique (e.g. radio frequency ablation RFA, embolization)
• patients which are intended to simultaneously get a surgery on other organs (excluding cholecystectomy)
• patients which are intended to simultaneously get a vascular anastomosis (e.g. portal vein resection)
• patients with known hepatic cirrhosis or known severe fibrosis (e.g. Ishak-score grade >4)
• patients with congenital metabolic diseases, in particular hepatic storage diseases
• hepatic infection with Echinococcus multilocularis
• patients with known non-infectious, auto-immune conditioned chronic inflammatory diseases (e.g. autoimmune hepatitis, Morbus Crohn, colitis ulcerativa)
• patients with severe cardiovascular diseases and/or severe diseases of the respiratory system which receive intensive care in any case (e.g. heart surgery, bypass surgery, cardiac valve replacement, unstable angina pectoris, severe coronary heart disease with intervention during the last 6 months, severe COPD (chronic obstructive pulmonary disease), severe asthma with concomitant cortisone medication)
• patients with severe bacterial infection at screening
• patients with known immunodeficiency
• heavy smokers (>20 cigarettes a day)
• patients which are unable to understand the study and its possible implications because of addiction or other diseases
• patients who are suspected not to cooperate or to comply to the trial protocol
• patients accommodated in an institution due to public or legal authority
• pregnant or lactating women
• women with child-bearing potential, excluding: negative pregnancy test and commitment to be sexually inactive until day 30 after surgery or discharge; postmenopause (12 months of natural occurring amenorrhoea); at least 6 weeks after ovariectomy with or without hysterectomy

at visit 2:

• patients anticipated for laparoscopic partial liver resection
• patients which are intended to be simultaneously treated with an interventional technique (e.g. radio frequency ablation RFA, embolization)
• patients which are intended to simultaneously get a surgery on other organs (excluding cholecystectomy)
• patients which are intended to simultaneously get a vascular anastomosis (e.g. portal vein resection)
• patients with known hepatic cirrhosis or known severe fibrosis (e.g. Ishak-score grade >4)
• hepatic infection with Echinococcus multilocularis
• patients with severe cardiovascular diseases and/or severe diseases of the respiratory system which receive intensive care in any case (e.g. heart surgery, bypass surgery, cardiac valve replacement, unstable angina pectoris, severe coronary heart disease with intervention during the last 6 months, severe COPD (chronic obstructive pulmonary disease), severe asthma with concomitant cortisone medication)
• patients anticipated for biliodigestive anastomosis and/or suffering from a Klatskin-tumor
• patients with a ASA (American Society of Anesthesiologists) classification >3