Dual source dual energy MDCT: comparison of 80 kVp and weighted average 120 kVp data for conspicuity of hypo-vascular liver metastases.

PURPOSE: To determine whether liver metastases conspicuity is improved at 80 kVp when compared with weighted average (WA) simulated 120 kVp data using dual source dual energy CT.

METHODS: A total of 11 patients with 44 hypo-vascular liver metastases underwent contrast enhanced Dual Energy CT (DECT). In all cases the subject's abdominal diameter measured
RESULTS: The mean size of the metastases was 2.6 cm. The mean +/- SD of the attenuation difference between the metastases and the normal liver was 78.37 +/- 24.6 at 80 kVp and 56.89 +/- 17.9 at 120 kVp. The mean difference in attenuation was significantly higher at 80 kVp (P < 0.001). In 2 cases, a metastases was only seen at 80 kVp. The difference between 80 and 120 kVp in terms of CNR was statistically significant (P = 0.042). In one patient, 11 lesions were not included in the smaller field of view of the 80 kVp detector. The conspicuity scores were rated as significantly better at 80 kv than at 120 kVp (P < 0.0001).

CONCLUSION: When compared with 120 kVp data, pure 80 kVp data acquired from a dual source dual energy MDCT scanner demonstrates greater attenuation differences and improved contrast to noise between metastatic disease and normal liver.