Percentage of signal intensity loss for characterisation of focal liver lesions in patients with chronic liver disease using ferucarbotran-enhanced MRI.

The purpose of this study was to determine the percentage of signal intensity loss (PSIL) threshold for the characterisation of focal liver lesions among patients with chronic liver disease. 55 nodules in 49 patients with chronic liver disease who underwent ferucarbotran-enhanced MR studies were included. Among the 49 patients, 40 had liver cirrhosis and 9 had chronic hepatitis. 8 haemangiomas, 3 focal nodular hyperplasia, 9 dysplastic nodules and 12 well, 19 moderately and 4 poorly differentiated hepatocellular carcinomas (HCCs) were revealed. The PSIL, signal-to-noise ratio and contrast-to-noise ratio of each lesion type were calculated. The diagnostic performance of PSIL on ferucarbotran-enhanced T(2) weighted images (PSIL(T2WI)) and T(2) weighted fat-suppression images (PSIL(FS-T2WI)) that characterised hepatic tumours was compared with receiver operating characteristic (ROC) analysis. Using ROC analysis, the diagnostic performance of PSIL(FS-T2WI) was superior to that of PSIL(T2WI) (p = 0.01). The mean PSIL(FS-T2WI) of the benign lesions was significantly higher than that of HCC (p<0.001), and the mean PSIL(FS-T2WI) of well-differentiated HCC was significantly higher than that of moderately/poorly differentiated HCCs (p = 0.001). With a PSIL(FS-T2WI) threshold of 40% in lesions characterising ferucarbotran-enhanced FS-T2WI, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 88.6%, 95%, 90.9%, 96.9% and 82.6%, respectively. In conclusion, with ferucarbotran-enhanced FS-T2WI, a PSIL(FS-T2WI) threshold of 40% for characterising focal liver nodules among patients with chronic liver disease is recommended. It is useful for distinguishing HCC from benign nodules.

Detection of hepatocellular carcinoma by ferucarbotran-enhanced magnetic resonance imaging: the efficacy of accumulation phase fat-suppressed T1-weighted imaging.

AIM: To evaluate the effectiveness of accumulation phase, fat-suppressed, T1-weighted imaging (FS-T1WI) when detecting hepatocellular carcinoma (HCC) by ferucarbotran-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: Thirty patients who underwent ferucarbotran-enhanced MRI, which resulted in 35 confirmed HCCs, were included in this prospective study. Two image sets were prepared and two radiologists independently reviewed these in two reading sessions; set A was without contrast-enhanced accumulation phase FS-T1WI and set B included contrast-enhanced accumulation phase FS-T1WI. All HCCs had been confirmed by operation (n=4), by biopsy (n=28), and by follow-up study for at least 1 year (n=3). RESULTS: The contrast-to-noise ratio significantly increased from -1.2+/-7.5 to 12.7+/-7.3 with contrast-enhanced accumulation phase FS-T1WI, but was only slightly increased from 12.2+/-10.3 to 15.5+/-12.2 with contrast-enhanced T2WI (p<0.001). The signal-to-noise ratio (SNR) was decreased with T1WI and T2WI for liver parenchyma. With T2WI, the SNR for HCCs was decreased; however, it was slightly increased with T1WI (p<0.001). Overall, 29 HCCs were detected using set A, and 35 nodules were identified using set B, which included the contrast-enhanced accumulation phase FS-T1WI. Thus, the detection rate significantly increased using post-contrast medium accumulation phase FS-T1WI (p<0.05). CONCLUSION: Due to the improved CNR with the post-contrast medium accumulation phase FS-T1WI, which helped to increase HCC detection, accumulation phase FS-T1WI is recommended as one of the routine protocols for inclusion in HCC detection.

Imaging well-differentiated hepatocellular carcinoma with dynamic triple-phase helical computed tomography.

To investigate the imaging appearance of well-differentiated hepatocellular carcinoma (HCC) on dynamic CT, a total of 38 histopathologically proven well-differentiated HCC were included in a retrospective study. We reviewed the contrast-enhanced dynamic CT of all 38 tumours for attenuation of each tumour in unenhanced scan, arterial-dominant and delayed portal venous phases. Our results showed that dynamic CT identified 26 (68.4%) out of the 38 lesions. The remaining 12 lesions were isodense compared with surrounding liver parenchyma in each dynamic CT phase. There was no statistically significant difference between the mean size of tumours detected by dynamic CT and that of tumours not detected by dynamic CT (p = 0.1). Of a total of 38 tumours, most were isodense (n = 19) or hypodense (n = 16) in unenhanced scan, mostly hyperdense (n = 18) or isodense (n = 15) in arterial-dominant phase and mostly isodense (n = 22) or hypodense (n = 15) in delayed portal venous phase. Enhancement of tumour was observed in 19 (50.0%) of 38 lesions. In conclusion, the ability of dynamic CT to detect well-differentiated HCC is poor, and negative CT findings cannot exclude the presence of well-differentiated HCC, especially if there is well-grounded clinical suspicion for HCC.