From the Guidelines
The recommended MRI imaging protocol for hepatocellular carcinoma (HCC) includes pre-contrast T1-weighted in-phase and out-of-phase sequences, T2-weighted sequences, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced imaging using extracellular contrast agents, as they are favored over hepatobiliary agents like gadoxetic acid for non-invasive diagnosis of HCC using MRI 1.
Key Components of the Protocol
- Pre-contrast T1-weighted in-phase and out-of-phase sequences
- T2-weighted sequences
- Diffusion-weighted imaging (DWI)
- Dynamic contrast-enhanced imaging using extracellular contrast agents
Dynamic Contrast Enhancement
- Gadolinium-based contrast agents should be administered at 0.1 mmol/kg
- Images acquired during:
- Arterial phase (15-30 seconds post-injection)
- Portal venous phase (60-90 seconds)
- Delayed phase (3-5 minutes)
Additional Considerations
- Slice thickness should be 5mm or less, with minimal or no gap between slices
- Fat suppression techniques should be applied to T2-weighted and post-contrast T1-weighted sequences
- The protocol should be tailored to the patient's renal function, with macrocyclic gadolinium agents preferred in patients with impaired renal function to minimize the risk of nephrogenic systemic fibrosis 1.
Rationale
The use of extracellular contrast agents is recommended over hepatobiliary agents for the non-invasive diagnosis of HCC using MRI, as stated in the EASL clinical practice guidelines on the management of hepatocellular carcinoma 1. This comprehensive protocol allows for the detection of hallmark imaging features of HCC, including arterial phase hyperenhancement followed by washout on portal venous or delayed phases, along with potential capsule appearance. DWI helps identify lesions with restricted diffusion, which is useful in the diagnosis of HCC.
From the FDA Drug Label
In all four studies, patients underwent a baseline, pre-contrast MRI followed by the administration of EOVIST at a dose of 0. 025 mmol/kg, with MRI performed immediately (the "dynamic" phase) and at 10 to 20 minutes following EOVIST administration (the "hepatocyte" phase).
The recommended MRI imaging protocol for hepatocellular carcinoma (HCC) involves a baseline pre-contrast MRI, followed by the administration of gadoxetate disodium (EOVIST) at a dose of 0.025 mmol/kg, with MRI performed in two phases:
- Dynamic phase: immediately after EOVIST administration
- Hepatocyte phase: 10 to 20 minutes after EOVIST administration 2.
From the Research
MRI Imaging Protocol for Hepatocellular Carcinoma (HCC)
The recommended MRI imaging protocol for HCC involves the use of various sequences to improve detection and characterization of the tumor.
- The use of diffusion-weighted imaging (DWI) sequence has been proposed as a diagnostic criterion for HCC, with a sensitivity of 77.1% or 76.1% depending on the radiologist 3.
- Dynamic MRI using gadolinium-based extracellular fluid (ECF) agents is useful for detection of hypervascular tumors and lesion characterization, but has limitations in the diagnosis of hypovascular HCCs and lesion characterization of nonhypervascular tumors 4.
- Gadoxetate disodium-enhanced MR imaging combining dynamic and hepatobiliary phase images has been shown to result in significantly improved sensitivity and diagnostic accuracy for detection of hypervascular HCC compared to multiphasic multidetector CT 5.
- DWI combined with contrast-enhanced MRI has higher sensitivity than DWI alone, and can be used to assess prognosis, predict response, monitor response to therapy, and distinguish tumor recurrence from treatment effect 6.
Comparison of Imaging Modalities
- A systematic review and meta-analysis found that MRI had significantly higher sensitivity (0.82 versus 0.66) and lower negative likelihood ratio (0.20 versus 0.37) than CT for the diagnosis of HCC in patients with cirrhosis 7.
- The specificities of MRI versus CT (0.91 versus 0.92) and the positive likelihood ratios (8.8 versus 8.1) were not different.
- All three modalities (CT, extracellular contrast-enhanced MRI, and gadoxetate-enhanced MRI) performed better for HCCs ≥2 cm, but performance was poor for HCCs <1 cm.
Clinical Applications
- DWI has a prominent role in patients who are not eligible for use of contrast on CT and MRI.
- Proposed clinical uses for DWI include assessing prognosis, predicting response, monitoring response to therapy, and distinguishing tumor recurrence from treatment effect.
- Ideally, DWI will help risk stratify patients and will participate in prognostic modeling.