Hepatocellular Phase Research Articles

Optimization of timing of hepatocellular phase imaging after gadoxetate disodium injection for evaluation of patients with neuroendocrine tumor.

Metastatic gastroenteropancreatic neuroendocrine neoplasms (mGEP-NEN) are indolent malignancies which undergo frequent imaging follow-up. Hepatocellular phase (HCP) MR with hepatocellular-specific contrast agent is widely used to evaluate mGEP-NEN liver metastases but is commonly performed after a 20-min delay which prolongs scan time. The purpose of this study was to evaluate if HCP MR at 15min offers comparable performance to 20-min delay for patients with mGEP-NEN undergoing routine imaging surveillance. In this IRB-approved retrospective study, we evaluated 52 patients with mGEP-NEN who were imaged for routine surveillance with gadoxetate disodium (Eovist®)-enhanced MR including 15- and 20-min delayed HCP. Two readers (R1, R2), blinded to HCP timing, independently reviewed each set of images in random order at least 1month apart. Readers assessed presence and conspicuity of metastases, and subjective image quality using 5-point scales. Readers quantified the number of metastases and diameter of the largest lesion. Statistical analysis was performed to determine individual-reader and inter-reader differences for qualitative and quantitative data. No differences were observed for subjective image quality (R1 p = 0.86, R2 p = 0.17) or lesion conspicuity (R1 p = 0.56, R2 p = 0.74) at 15min and 20min for either reader. Individual-reader concordance correlation coefficient between 15 and 20min was high for number of metastases detected (R1 = 0.9842, R2 = 0.9579) and diameter of largest metastasis (R1 = 0.9629, R2 = 0.8859). HCP imaging at 15min provides similar diagnostic yield to standard 20-min delay, which may help reduce the scan time and costs, and improve throughput and patient satisfaction.

Cholangiocarcinoma: spectrum of appearances on Gd-EOB-DTPA-enhanced MR imaging and the effect of biliary function on signal intensity.

BackgroundTo describe the Gd-EOB-DTPA-enhanced MRI appearances of cholangiocarcinoma, and evaluate the relative signal intensities (RSIs) changes of major abdominal organs, and investigate the effect of total bilirubin (TB) levels on the RSI.Methods25 patients with pathologically-proven cholangiocarcinoma underwent Gd-EOB-DTPA-enhanced MRI. The visualization of the biliary system during biliary phase (BP) was observed. RSIs of the abdominal aorta (A), portal vein (V), liver (L), and spleen (S) were measured.ResultsOn hepatocellular phase (HP), exophytic tumors (n =10) and infiltrative tumors (n =10) were hypointense, polypoid tumors (n = 2) were hypointense, and combined type tumors (n = 3) had mixed appearances. While patients with normal TB levels (≤22 μmol/L, n = 12) had clear visualization of the biliary tree during BP, those with elevated TB levels (>22 μmol/L, n = 13) had obscured or no visualization. In addition, patients with normal TB levels had higher RSIA, RSIV and RSIS than those with elevated TB levels on all dynamic phases (P <0.001), and lower RSIA, RSIV and RSIS on HP and BP (P <0.001). Patients with normal TB levels had higher RSIL than those with elevated TB levels on all phases (P <0.001).ConclusionsRSIs of major abdominal organs reflected underlying biliary function. Cholangiocarcinoma patients with elevated TB levels had delayed excretion of Gd-EOB-DTPA compared with patients with normal TB levels.

Focal hepatic lesions in Gd-EOB-DTPA enhanced MRI: the atlas

ObjectiveThis article reviews the different technical aspects and pitfalls of gadolinium (Gd)-ethoxibenzyl (EOB)-diethylenetriamine pentaacetic acid (DTPA) and the advantages of the hepatocellular phase (HCP) and defines its specific imaging features of liver lesions.BackgroundGd-EOB-DTPA is a contrast agent with combined properties of a conventional non-specific extracellular and a hepatocyte-specific contrast agent. Benign cirrhosis-associated nodules are characterised by isointensity in dynamic imaging and the HCP. Hepatocellular carcinomas (HCCs) usually show hyperenhancement in the arterial phase, with washout in the portal vein pressure (PVP) and hypointensity in the HCP. Among other characteristic findings, we have the mosaic pattern, a capsule, the “nodule-in-nodule” appearance and the satellite nodules. The fibrolamellar HCC is a large enhancing heterogeneous lesion, on a non-cirrhotic liver, with a hypointense scar in every sequence. THIDs (transient hepatic intensity differences) are perfusional alterations, characterised by hyperintensity in the arterial phase, with no alterations in the rest of the sequences including the HCP. Adenoma and focal nodular hyperplasia (FNH) are lesions, occurring more frequently in young women, with brisk arterial enhancement, differentiated by the scar and the uptake of Gd-EOB-DTPA in the HCP. Focal eosinophilic infiltration is a difficult diagnosis, with characteristics such as a non-spherical shape and irregular borders suggesting it. Besides these lesions, in which Gd-EOB-DTPA has a clear advantage, there are a few where the specificities of this agent can be troublesome: haemangiomas, focal fat/sparing, foreign body reaction, cholangiocarcinoma and metastases.ConclusionGd-EOB-DTPA is comparable to extracellular agents, and uptake by functioning hepatocytes in the delayed phase provides additional information that further improves detection and characterisation of many hepatic lesions.Main Messages Gd-EOB-DTPA offers advantages for the imaging of many liver lesions including HCC, fibrolamellar HCC, FNH and adenoma. The properties of Gd-EOB-DTPA can pose problems when dealing with haemangiomas, cholangiocarcinoma and metastases among others. The uptake of Gd-EOB-DTPA by functioning hepatocytes in the delayed phase provides additional information that further improves detection and characterisation of many hepatic lesions.