Lipiodol CT Scan

Background and indications

Lipiodol CT is a diagnostic technique used to detect small hepatocellular carcinomas (HCC) difficult to visualize by conventional imaging. Lipiodol (iodized oil) is selectively injected into the hepatic artery and preferentially accumulates in hypervascular tumor nodules. A CT scan performed 1-2 weeks after injection shows Lipiodol retention in tumors.

The main indication is detection of small HCC (< 1-2 cm) not visible or equivocal on conventional MRI and CT, particularly in pre-transplant or pre-resection workup on cirrhotic liver.

Pre-procedure assessment

Assessment includes liver MRI (with equivocal results motivating the examination), hepatic blood panel, AFP measurement, and tumor board discussion.

Procedure

In two steps: (1) Hepatic arteriography with injection of 5-10 mL Lipiodol into the proper hepatic artery or selectively into a lobe, under local anesthesia and sedation, via femoral catheter. (2) Non-contrast hepatic CT performed 7-14 days later showing Lipiodol retention in tumor lesions (hyperfixation). Arteriography takes 30-60 minutes.

Results and scientific evidence

Lipiodol CT has 80-90% sensitivity for HCC > 1 cm and detects lesions not visible on MRI in 10-20% of cases. It is gradually being supplanted by hepatocyte-specific MRI agents (gadoxetic acid) but remains useful in difficult cases where MRI is contraindicated or non-contributory.

Risks and complications

Abdominal pain (10-20%), nausea (5-10%), minor post-embolization syndrome (5-10%). Major complications are rare (< 1%).

Recovery

Same-day discharge after arteriography. Control CT at 7-14 days as outpatient.

Practical information

The procedure is performed as an outpatient or short inpatient stay depending on the case.