Usefulness of EOB-MRI for distinguishing between hyperplastic nodules and hepatocellular carcinoma (HCC)
Nagasaki Harbor Medical Center
Dr. Takahide Honda, Dept. of Radiology
DATE : 2021
Introduction
Patient’s background
Male; 70s; body weight: 72 kg; chronic hepatitis C
Assessment objectives
After treatment of chronic hepatitis C with a direct-acting antiretroviral, the patient was monitored with periodic observation. EOB-MRI was performed as screening for HCC.
Contrast agent used
Gadoxetate disodium(Gd-EOB-DTPA) injection, 0.1 mL/kg
Case explanation
The patient developed chronic hepatitis with multiple early, dark-staining lesions.
The conditions put forward for differentiation were HCC, and hyperplastic nodules with abnormal hepatic blood flow.
In the EOB-MRI hepatobiliary phase, most lesions were delineated as ring-shaped with high signals, and the first possibility considered was that they were hyperplastic nodules with abnormal hepatic blood flow.
In the portal and late phases, absence of both wash-out and decrease in ADC value also supported the lesions being hyperplastic nodules rather than HCC.
Contrast computed tomography (CT), angiography, CT during hepatic angiography (CTHA), and CT during arterial portography (CTAP) were performed as a thorough examination, but none of these showed the early, dark-staining lesions found by EOB-MRI, and on the basis of this finding also HCC was considered to be ruled out.
In the subsequent follow-up, the multiple hepatic nodules were seen to be lesions that had at one time increased in size, but now all showed a tendency to contraction, so their clinical course was consistent with them being hyperplastic nodules.
It was difficult to determine with this patient whether blood flow to hyperplastic nodules was predominantly from the hepatic artery or the portal vein, but the nodules developed in association with enhancement of the AP shunt over time, and abnormal hepatic blood flow due to the AP shunt is therefore considered to be the cause.
Imaging findings
In the arterial phase (B), nodular, faint, early, dark staining is sometimes observed in the left lobe lateral segment and right lobe posterior segment. A higher signal than the surrounding hepatic parenchyma was seen from the portal phase (not shown) to the late phase (C), and no clear wash-out was seen. In the hepatobiliary phase (D), numerous lesions were delineated with high signals and ring shapes. In the arterial phase, early dark staining, considered to be the AP shunt, was found, primarily in the right lobe anterior segment and left lobe medial segment, and nodules were not identified in this region.
Fig. 1. EOB-MRI: A: pre-contrast; B: arterial phase; C: late phase; D: hepatobiliary phase
With T2WI (A), the nodules showed moderately high signals, whereas with T1WI (B) the nodules showed slightly lower signals than to isosignals with the rest of the liver. In DWI (C), numerous nodules showed isosignals with the rest of the liver, but some lesions showed faint high signals, and the ADC values (D) were elevated.
Fig. 2. EOB-MRI (same cross-section as in Fig. 1): A: T2WI; B: T1WI; C: DWI; D: ADC map
In the dynamic CT arterial phase (B), dark staining, considered to be the AP shunt, was found, primarily in the right lobe anterior segment and left lobe medial segment. The nodular lesions delineated by MRI were not identified.
Fig. 3. Dynamic CT: A: simple CT; B: arterial phase; C: portal phase; D: late phase
With CTHA, early dark staining, considered to be the AP shunt, was found, primarily in the right lobe anterior segment and left lobe medial segment. With CTAP, this region was poor-contrast region. The nodular lesions delineated by MRI were not identified.
Fig. 4. CTHA and CTAP
At the initial celiac arteriography (Year X), the AP shunt was found, primarily in the right lobe of the liver, and selective angiography from the hepatic artery branch (not shown) confirmed the shunt from A5 and the left lobe branch to the portal vein. The nodular lesions delineated by MRI were not identified. In Year 2 + X, 2 years later, celiac arteriography showed an enhanced AP shunt in both liver lobes.
Fig. 5. Angiography
Photography protocol
| Imaging type | Photography sequence | Photography duration (s) | TE （msec） | TR （msec） | FA （deg） | Fat sat (type) | ETL (number) | P-MRI (Reduction Factor) |
| T2WI cor | HASTE | 18 | 64 | 750 | 120 | ー | ー | 3 |
| T2WI | HASTE | 18 | 73 | 500 | 115 | ー | ー | 2 |
| Dual echo | 2D FLASH | 18 | 1.26 2.52 | 180 | 42 | ー | ー | 2 |
| Contrast agent administration | ||||||||
| Dynamic | VIBE | 15 | 1.16 | 3.13 | 10 | Q-fatsat | ー | 3 |
| DWI | EPI | ー | 59 | 1300 | 90 | SPAIR | ー | 2 |
| T2WI fs | TSE | 84 | 77 | 3000 | 120 | SPAIR | 23 | 2 |
| Heavy T2 | HASTE | 68 | 232 | 1600 | 158 | ー | ー | 2 |
| HBP | VIBE | 15 | 1.16 | 3.13 | 10 | Q-fatsat | ー | 3 |
| HBP cor | VIBE | 20 | 1.17 | 3.41 | 10 | Q-fatsat | ー | 3 |
| Imaging type | Holding breath (yes/no) | NEX (calculation number) | k-space | In-plane resolution (mm) | Slice thickness (mm) | FOV (mm) | Rectangular FOV(%) | Phase direction (step number) |
| T2WI Cor | Yes | 1 | ー | 0.96×0.96 | 7.0 | 370 | 100 | 250 |
| T2WI | Yes | 1 | ー | 1.19×1.19 | 5.0 | 380 | 81.3 | 156 |
| Dual echo | Yes | ー | Interleaved | 0.72×0.72 | 5.0 | 380 | 75 | 163 |
| Contrast agent administration | ||||||||
| Dynamic | Yes | 1 | Sequential | 1.16×1.16 | 3.0 | 380 | 75 | 180 |
| DWI | No | ー | ー | 1.32×1.32 | 5.0 | 380 | 77.1 | 81 |
| T2WI fs | Yes | 1 | Interleaved | 1.16×1.16 | 5.0 | 380 | 75 | 168 |
| Heavy T2 | Yes | 1 | ー | 1.16×1.16 | 5.0 | 380 | 78.1 | 198 |
| HBP | Yes | 1 | Sequential | 1.16×1.16 | 3.0 | 380 | 75 | 180 |
| HBP cor | Yes | 1 | Sequential | 1.12×1.12 | 3.0 | 360 | 100 | 240 |
| Imaging type | Read direction (matrix number) | Actual scan (%) | Slice Gap (mm) | Slice number | Three-dimensional partition number | Three-dimensional actual scan (%) | 3D over Sampling(%) |
| T2WI Cor | 384 | 65 | 1.0 | 22 | ー | ー | ー |
| T2WI | 320 | 60 | 1.0 | 32 | ー | ー | ー |
| Dual echo | 256 | 85 | 1.0 | 32 | ー | ー | ー |
| Contrast agent administration | |||||||
| Dynamic | 320 | 75 | 0 | 80 | 1 | 60 | 20 |
| DWI | 140 | 75 | 1.0 | 32 | ー | ー | ー |
| T2WI fs | 320 | 70 | 1.0 | 32 | ー | ー | ー |
| Heavy T2 | 320 | 79 | 1.0 | 32 | ー | ー | ー |
| HBP | 320 | 75 | 0 | 80 | 1 | 60 | 20 |
| HBP cor | 320 | 75 | 0 | 80 | 1 | 60 | 20 |
Devices used and contrast conditions
| MRI device | MAGNETOM Skyra |
| Automatic injection device | Sonic Shot GX (Nemoto Kyorindo) |
| Workstation | ー |
| Contrast conditions | Dose (mL) | Administration rate (mL/s) | Photography timing | |
| Gadoxetate disodium(Gd-EOB-DTPA) | 0.1mL/kg | 1.5 | With bolus-tracking, 5, 60, 180 and 240 s after the contrast agent reached the abdominal aorta*; and in the hepatobiliary phase (from 900 s) | |
| Physiological saline solution for flushing | 25 | 1.5 |
* The timing of imaging in the late phase of the MRI imaging used with this patient was after 240 s.
Usefulness of Gadoxetate disodium(Gd-EOB-DTPA) contrast MRI with this patient
Progress in diagnostic imaging has increased the frequency of detecting benign hepatocellular nodules, and their differentiation from hypervolemic tumors, especially HCC, has thus become an important issue.
With this patient, early dark-stained nodules, which occur frequently in chronic hepatitis, were found by EOB-MRI, and differentiation from HCC was required.
In 10 to 15% of cases of HCC, a high signal is shown in the hepatobiliary phase of EOB-MRI, and the high signal has been reported to show a nodule-in-nodule pattern, being internally homogeneous, and mosaic-like, with an associated low signal at the margin of the high-signal region.
This patient’s lesions showed a ring-shaped high signal in the hepatobiliary phase of EOB-MRI. As such findings have been reported with focal nodular hyperplasia (FNH), FNH-like nodules, nodular regenerative hyperplasia, etc., this case constitutes grounds for paying more attention to the possibility of lesions being hyperplastic nodules with abnormal blood flow than to that of them being HCC. In addition to the above, signs that are useful for differentiation include the ADC values of lesions, and presence or absence of wash-out.
In addition, EOB-MRI in which the lesion is delineated with a low signal in the hepatobiliary phase is considered to be useful for detecting new HCC during development of the AP shunt and multiple hyperplastic nodules showing early dark staining, as with this patient.
Precautions relating to administration
9. Precautions relating to patients with specific background factors (taken from the Package Insert)
9.8 Elderly patients
Administration must be performed with care, and with sufficient monitoring of the patient’s condition.
Elderly patients generally have depressed physiological function.
- *The case introduced is just one clinical case, so the results are not the same as for all cases.
- *Please refer to the Package Insert for the effects and indications, dosage and administration method, and warnings, contraindications, and other precautions with use.
