Liver Dynamic Contrast-Enhanced MRI Requirements for Assessment of HCC.
| Characteristic | Specification | Comment |
|---|---|---|
| MRI equipment | ≥ 1.5 T | |
| Contrast agent | Gadolinium-based agents or hepatobiliary-specific agents (gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid) | Necessary to inject the manufacturer's suggested dose of contrast agent at a rapid rate of 1-3 mL/sec |
| Required imaging technique | 1. T2-weighted image | Necessary for the patient to hold their breath for approximately 20 sec for optimal dynamic MRI |
| 2. In/opposed phase T1-weighted image | ||
| 3. Diffusion-weighted image | ||
| 4. Fat-suppressed three-dimensional T1-weighted image before and after contrast administration | ||
| Dynamic phases and timing required for dynamic contrast-enhanced MRI | 1. Late arterial phase 2. Portal venous phase 3. Delayed or transitional* phase |
1. 5 sec after maximum aortic enhancement |
| 2. 1 min after contrast injection (35-55 sec after the arterial phase) | ||
| 3. 2-3 min after contrast injection (optimal timing is 3 min) | ||
| *It is called the transitional phase because it is enhanced by hepatocyte-specific uptake for hepatobiliary-specific contrast agents. | ||
| Hepatobiliary-specific contrast agent is helpful for detecting small HCCs because it has a hepatobiliary phase 10-40 min after contrast injection and the liver parenchyma shows strong enhancement by hepatocyte-specific uptake | ||
| Slice thickness and resolution | Thickness: < 5 to -8 mm | |
| Resolution: < 3 mm |
HCC = hepatocellular carcinoma, MRI = magnetic resonance imaging