Therapeutic ethanol injection of hepatocellular carcinomas undetectable by angiography and Lipiodol computed tomography

Timing of the hepatic arterial phase at Gd-EOB-DTPA-enhanced hepatic dynamic MRI: comparison of the test-injection and the fixed-time delay method

PURPOSE

To compare the fixed-time- and the test-injection method with respect to the image quality of hypervascular hepatocellular carcinoma (HCC) and the adequacy of timing of the hepatic arterial phase (HAP) in Gd-EOB-DTPA (EOB) enhanced MRI.

MATERIALS AND METHODS

We studied 63 patients with computed tomography (CT) -proven hypervascular HCC: 30 (group 1) were scanned HAP using the fixed-time delay method (protocol 1); in the other 33 (group 2), we applied the test-injection method (protocol 2). We compared the protocols with respect with tumor-to-liver contrast (TLC), contrast-to-noise-ratio (CNR), and relative enhancement of the liver and tumor (REL , RET ) during HAP. Two radiologists compared the adequacy of HAP, image contrast, image noise, and overall image quality.

RESULTS

Under protocol 2, TLC, CNR, and REL and RET of hypervascular HCC were significantly higher (P < 0.01). The proportion of optimal HAP was significantly higher for protocol 2 than protocol 1 (P < 0.01). The visual score of the image contrast and the overall image quality were significantly higher in group 2 than group 1 (P = 0.02 and P = 0.01, respectively).

CONCLUSION

At EOB-enhanced hepatic dynamic MRI, the test-injection method yielded better image quality of hypervascular HCC and improved adequacy of timing of HAP.

Comparison of Test-Injection Method and Fixed-Time Method for Depiction of Hepatocellular Carcinoma Using Dynamic Steady-State Free Precession Magnetic Resonance Imaging

OBJECTIVE

The purpose of this study was to clarify the usefulness of the test-injection method as compared with the fixed-time method in dynamic magnetic resonance (MR) imaging of hepatocellular carcinoma (HCC).

METHODS

Ninety-seven patients with a total of 118 hepatocellular carcinomas underwent 3-dimensional fast imaging with steady-state free precession (3D-FISP) for dynamic study of the liver as well as catheter-assisted computed tomography hepatic angiography (CTHA) for preoperative evaluation. In 42 cases, the fixed-time method (30-second scan time delay in the hepatic arterial phase [HAP]) was performed (group 1), and in 55 cases, the test-injection method was performed (group 2). The following parameters were evaluated: 1) the adequacy of the HAP, 2) tumor vascularity using CTHA findings as a gold standard, and 3) the contrast-to-noise ratio (CNR) of the HCC during the HAP of dynamic MR imaging.

RESULTS

In group 1, 79% (33 of 42) of the cases were obtained at the optimal HAP; the percentage in group 2 was 98% (54 of 55) of the cases. This difference was statistically significant (P < 0.05). The vascularity of 82% of the tumors in group 1 and 89% of those in group 2 was diagnosed correctly. Regarding hypervascular tumors, correct evaluation of tumor vascularity was made in 87% of group 1 cases and 95% of group 2 cases. No significant difference was present between the 2 groups (total: P = 0.43, hypervascular HCC: P = 0.29). 3) The CNR calculated for all HCCs in group 2 (mean +/- SD: 8.66 +/- 11.0) was significantly higher than that for HCCs in group 1 (4.29 +/- 9.44; P < 0.05). As for the hypervascular tumors, the CNR calculated for group 2 (mean +/- SD: 9.89 +/- 10.6) was also significantly higher than that for group 1 (5.52 +/- 9.81; P < 0.05).

CONCLUSION

The 3D-FISP dynamic MR imaging using the test-injection method resulted in better demonstration of HCC than the 3D-FISP using the fixed-time method.

[Diagnosis and therapy of hepatocellular carcinoma]

During the past decade, the diagnostic technologies concerning the hepatocellular carcinoma have been enriched by the vascular doppler ultrasound, the ultrasound echo-enhancing agents and the magnetic resonance tomography. The therapeutic possibilities have been augmented by the percutaneous ethanol instillation therapy, the combination of local therapies with transcatheter arterial embolisation and the more effective after-treatment after transplantation and segment resection. The use of the respective treatment modalities depends on the tumor constellation, the functional liver reserve, the patients general condition and the risk/benefit ratio of the treatment. The quality of life should be optimized because of the poor tumor prognosis. As there have been no real advances in the treatment of hepatocellular carcinoma to date, the prevention and early diagnosis of the tumor in high risk populations is of utmost importance.

Endothelial-cell injury of the basilar artery caused by ethanol infusion in dogs

This study in mongrel dogs was designed to observe the effects of ethanol on both endothelial cells of the basilar artery and brain function. By use of sterile surgical technique, a super-selective catheter was placed in the proximal portion of the basilar artery in the dogs. Five dogs received 3 ml of 25% ethanol and 5 dogs received 3 ml of 50% of ethanol through the catheter over 2 minutes. The remaining 5 dogs received 3 ml of saline as a control. Auditory brain stem response (ABR) was monitored for 2 hours after ethanol infusion, and then perfusion-fixation was performed from the heart with 4% paraformaldehyde. The basilar artery was observed with scanning electron microscopy after routine procedures. The endothelial cells were intact in the control group. The 50% group showed a higher level of injury to the endothelium as well as a higher degree of platelet adhesion and fibrin clot formation compared with the 25% group. The extensive endothelial-cell damage subsequently caused thrombus formation. The ABR disappeared immediately after ethanol infusion in both ethanol groups, and recovered gradually in the 25% group, but did not re-appear during the time course of 2 hours in the 50% group. The ethanol less than 25% in concentration near the endothelium is considered to be safe as a transcatheter embolic agent with the attention to the central toxicity.