Published online Jul 28, 2016. doi: 10.4329/wjr.v8.i7.683
Peer-review started: January 22, 2016
First decision: March 1, 2016
Revised: March 14, 2016
Accepted: May 10, 2016
Article in press: May 11, 2016
Published online: July 28, 2016
Processing time: 185 Days and 23.5 Hours
AIM: To find out if magnetic resonance (MR)-signal characteristics of hepatocellular carcinomas (HCC) correlate with perfusion parameters assessed by volume perfusion computed tomography (VPCT).
METHODS: From October 2009 to January 2014, 26 (mean age, 69.3 years) patients with 36 HCC lesions who underwent both VPCT and MR liver imaging were analysed. We compared signal intensity in the T1w- and T2w-images and wash-in/wash-out kinetics on post-contrast MR images with mean values of blood flow (BF, mL/100 mL per minute), blood volume (BV, mL/100 mL), k-trans (mL/100 mL per minute), arterial liver perfusion (mL/100 mL per minute), portal venous perfusion and hepatic perfusion index (HPI, %) obtained by VPCT. Signal intensity on magnetic resonance imaging (MRI) was classified hyper/iso/hypointense compared with surrounding liver parenchyma.
RESULTS: Signal intensity on native T1w- and T2w-images was hyper/iso/hypo in 4/16/16 and 21/14/1 lesions, respectively. Wash-in and wash-out contrast kinetics were found on MRI in 33 of 36 lesions (91.7%) and 25 of 36 lesions (69.4%), respectively. The latter was observed significantly more often in higher graded lesions (P < 0.005). HPI was 94.7% ± 6.5%. There was no significant relationship between lesion’s MR-signal intensity, MR signal combinations, size and any of the VPCT-perfusion parameters. However HPI was constantly high in all HCC lesions.
CONCLUSION: VPCT parameters add limited value to MR-lesion characterization. However in HCC lesions with atypical MR signal characteristics HPI can add a parameter to ensure HCC diagnosis.
Core tip: The study shows no correlation between hepatocellular carcinomas (HCC) perfusion parameters and any of the possible magnetic resonance (MR)-signal characteristics of HCC as displayed at MR imaging as well as tumor size. However hepatic perfusion index measured with help of volume perfusion computed tomography (VPCT) was very high in all HCC lesions and the arterial liver perfusion decreased with increasing tumor dedifferentiation. For this purpose, we advocate the additional use of perfusion-based liver tumor identification by VPCT for accurate HCC detection and characterisation in case of unclear MR signal characteristics.