Non-tumorous enhancement caused by cholecystic venous inflow shown on biphasic CT hepatic arteriography: comparison with hepatocellular carcinoma

Change in Imaging Findings on Angiography-Assisted CT During Balloon-Occluded Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma

PURPOSE

To evaluate changes in imaging findings on CT during hepatic arteriography (CTHA) and CT during arterial portography (CTAP) by balloon occlusion of the treated artery and their relationship with iodized oil accumulation in the tumor during balloon-occluded transcatheter arterial chemoembolization (B-TACE).

METHODS

Both B-TACE and angiography-assisted CT were performed for 27 hepatocellular carcinomas. Tumor enhancement on selective CTHA with/without balloon occlusion and iodized oil accumulation after B-TACE were evaluated. Tumorous portal perfusion defect size on CTAP was compared with/without balloon occlusion. Factors influencing discrepancies between selective CTHA with/without balloon occlusion and the degree of iodized oil accumulation were investigated.

RESULTS

Among 27 tumors, tumor enhancement on selective CTHA changed after balloon occlusion in 14 (decreased, 11; increased, 3). In 18 tumors, there was a discrepancy between tumor enhancement on selective CTHA with balloon occlusion and the degree of accumulated iodized oil, which was higher than the tumor enhancement grade in all 18. The tumorous portal perfusion defect on CTAP significantly decreased after balloon occlusion in 18 of 20 tumors (mean decrease from 21.9 to 19.1 mm in diameter; p = 0.0001). No significant factors influenced discrepancies between selective CTHA with/without balloon occlusion. Central area tumor location, poor tumor enhancement on selective CTHA with balloon occlusion, and no decrease in the tumorous portal perfusion defect area on CTAP after balloon occlusion significantly influenced poor iodized oil accumulation in the tumor.

CONCLUSIONS

Tumor enhancement on selective CTHA frequently changed after balloon occlusion, which did not correspond to accumulated iodized oil in most cases.

Epinephrine-infused CTHA for HCCs

BACKGROUND

Changes in the relative arterial flow to hepatocellular carcinomas and adjacent normal liver with hepatic arterial epinephrine infusion were studied with CT hepatic arteriography (CTHA).

METHODS

Data from 31 pathologically confirmed hepatocellular carcinomas were retrospectively analyzed in 16 patients who simultaneously underwent CT during arterial portography (CTAP) and CTHA for examination of liver tumors and then CTHA with hepatic arterial epinephrine infusion.

RESULTS

Regarding visual analysis, tumor enhancement of hepatocellular carcinomas on CTHA after hepatic arterial epinephrine injection changed as follows: more clear in 83.9% (26/31), equal in 16.1% (5/31), and less clear in 0% (0/31). As for the quantitative analysis, CT attenuation value of hepatocellular carcinomas significantly increased after injection of epinephrine (mean increase from 225.8 to 333.9 HU; P < 0.0001, paired t test). The CT attenuation value of normal liver parenchyma around a tumor significantly decreased after injection of epinephrine (mean decrease from 101.1 to 84.6 HU; P < 0.0001, paired t test). The tumor-to-liver conspicuity significantly increased after injection of epinephrine (mean increase from 124.6 to 249.2 HU; P < 0.0001, paired t test).

CONCLUSIONS

Hepatic arterial epinephrine infusion changes the relative arterial flow of hepatocellular carcinomas.

Multi-phasic CT arterial portography and CT hepatic arteriography improving the accuracy of liver cancer detection

AIM: To evaluate the value of multi-phasic CT arterial portography (CTAP) and CT hepatic arteriography (CTHA) in differential diagnosis of liver diseases, and to improve the specificity of CTAP and CTHA for liver cancer detection.

METHODS: From January 1999 to December 2002, multi-phasic CTAP and CTHA were performed in 20 patients with suspected liver disease. CT scanning was begun 25 s, 60 s and 120 s for the early-, late- and delayed-phase CTAP examinations, and 6sec, 40 s and 120 s for the early-, late-and delayed-phase CTHA examinations respectively, after a transcatheter arterial injection of non-ionic contrast material. If a lesion was diagnosed as a liver cancer, transcatheter hepatic arterial chemoembolization (TACE) treatment was performed, and the follow-up CT was performed three or four weeks later.

RESULTS: All eighteen HCCs in 12 cases were shown as nodular enhancement on early-phasic CTHA. The density of the whole tumor decreased rapidly on late and delayed phases, and the edge of 12 tumors (12/18) remained relatively hyperdense compared with the surrounding liver tissue, and demonstrated as rim enhancement. All HCCs were shown as perfusion defect nodules on multi-phasic CTAP. Five tumors (5/18) were shown as rim enhancement on delayed-phasic CTAP. Rim enhancement was shown as 1 to 2-mm-wide irregular, uneven and discontinuous circumferential enhancement at late-, and delayed-phase of CTHA or CTAP. Five pseudolesions and 4 hemoangiomas were found in multi-phasic CTAP and CTHA. No pseudolesions and hemoangiomas were shown as rim enhancement on late- or delayed-phasic CTHA and CTAP.

CONCLUSION: Multi-phasic CTAP and CTHA could help to recognize the false-positive findings in CTAP and CTHA images, and improve the accuracy of CTAP and CTHA of liver cancer detection.

Effect of prostaglandin E1 on contrast enhanced CT of the liver: statistical analysis during arterial portography

PURPOSE

To determine the diagnostic effect of prostaglandin E(1) on contrast enhancement quality of CT during arterial portography (CTAP).

MATERIALS AND METHODS

Our patients population included 30 patients (11 women, 19 men; age range, 41 approximately 81 years) with liver tumors (23 hepatocellular carcinoma and 7 metastatic liver tumor) who had undergone angiography. We divided the 30 patients, who had undertaken CTAP twice, into two groups at random (group A; n=15, group B; n=15). In group A, first CTAP was performed without prostaglandin E(1). Approximately 5 minutes later, a second CTAP was again initiated 30 seconds after injection of prostaglandin E(1) under the same conditions. In group B, prostaglandin E(1) was injected before the first CTAP only. We measured the mean CT numbers and standard deviation (SD) numbers of anterior, posterior, medial and lateral segments in the liver at the same section of the CTAP using the same size and location of the regions of interest, and these values with and without prostaglandin E(1) were compared.

RESULTS

1) CT numbers: The CT numbers were significantly increased in the medial segment after the injection of prostaglandin E(1) (p<0.05) in all cases of both groups. On the other hand, they were clearly decreased in the posterior segment after the injection of prostaglandin E(1) (p<0.05) in both groups. There were no statistical differences in the CT numbers in the anterior and lateral segments in all patients. In addition, the CT numbers of anterior and posterior segments showed high attenuation compared with the medial and lateral segments in group A without prostaglandin E(1). 2) SD numbers: The SD numbers, which are an index of the homogeneous enhancement, were significantly decreased in the posterior, medial and lateral segments after the injection of prostaglandin E(1) (p<0.01, p<0.05, p<0.01, respectively) in both groups. There were no significant differences in the SD numbers in the anterior segment regardless of the injection of prostaglandin E(1) in all cases.

CONCLUSION

CTAP with injection of prostaglandin E(1) makes contrast enhancement of liver parenchyma more homogeneously than the conventional procedure, and it may be a useful technique for the detection of liver tumors.

Effects of prostaglandin E(1) injection through the superior mesenteric artery on the hemodynamics of hepatocellular carcinoma

OBJECTIVE

The purpose of our study was to assess the effects of portal blood flow on contrast enhancement in hepatocellular carcinoma lesions on CT hepatic arteriography.

SUBJECTS AND METHODS

We examined 43 tumors in 39 patients who simultaneously underwent CT during arterial portography and CT hepatic arteriography for examination of liver tumors and then CT hepatic arteriography with prostaglandin E(1) injection via the superior mesenteric artery. All lesions pathologically confirmed to be hepatocellular carcinomas exhibited portal perfusion defects on CT during arterial portography. Changes in CT attenuation, size, and shape of liver tumors visualized on CT hepatic arteriography after intraarterial injection of prostaglandin E(1) were studied. In addition, changes in CT attenuation of the liver parenchyma surrounding the tumor were measured.

RESULTS

The CT attenuation increased significantly after injection of prostaglandin E(1) in 91% (39/43) of the lesions (mean increase from 176.4 to 206.6 H; p = 0.0006, paired t test). The size and shape of the enhanced area generally did not change. The CT attenuation of the liver parenchyma surrounding each liver tumor significantly decreased in 58% (25/43) of the hepatocellular carcinoma lesions (mean decrease from 94.8 to 92.0 H; p = 0.0166, paired t test) and lesion conspicuity increased in 91% (39/43) of the tumors.

CONCLUSION

Lesion conspicuity on CT hepatic arteriography between hepatocellular carcinoma and the surrounding liver parenchyma increased because of greater portal perfusion after the prostaglandin E(1) injection.

Value of intraarterial prostaglandin E(1) injection during CT hepatic arteriography

OBJECTIVE

The purpose of our investigation was to determine if injection of prostaglandin E(1) during CT hepatic arteriography could help physicians to distinguish tumors from nonportal venous flow-related pseudolesions in the region of the gallbladder fossa.

SUBJECTS AND METHODS

In 34 patients who underwent CT during arterial portography to detect liver tumors, CT hepatic arteriography was performed before and after prostaglandin E(1) injection via the superior mesenteric artery. Between each study, an interval of 10 minutes was set. On CT hepatic arteriogram obtained 15 to 20 sec after prostaglandin E(1) injection, we distinguished changes in the size and shape of pseudolesions in the liver around the gallbladder as well as those of 42 tumorous lesions. In addition, we measured the change in CT attenuation of pseudolesions.

RESULTS

The size of the enhanced area of pseudolesions visible on CT hepatic arteriography decreased in 69% (25/36) of the pseudolesions after intraarterial prostaglandin E(1) injection, with the mean diameter diminishing from 14.1 mm to 8.8 mm. Notably, in 11 pseudolesions, the enhanced area disappeared. In 86% (31/36), the CT attenuation decreased with the mean attenuation, diminishing from 211.3 H to 163.8 H. However, the size and shape of the enhanced area of tumorous lesions did not change.

CONCLUSION

The hemodynamic features of pseudolesions on angiographically assisted helical CT scans caused by cholecystic venous inflow are easily influenced by increased portal venous flow. Consequently, pseudolesions around the gallbladder usually can be distinguished from tumorous lesions by adding prostaglandin E(1) injection via the superior mesenteric artery during CT hepatic arteriography.