Diffusion- and T2-weighted MR Imaging of the Liver: Effect of Intravenous Administration of Gadoxetic Acid Disodium

Abstract

Purpose: We evaluated the eŠect of intravenous administration of gadoxetic acid disodium to hepatic lesions and liver parenchyma on T 2 -weighted (T 2 WI) and diŠusion-weighted imaging (DWI).Materials and Methods: One hundred and one consecutive patients with 259 hepatic lesions underwent T 2 WI and DWI (b-values of 500 and 1000 s/mm 2 ) before and after gadoxetic acid administration. We compared the ratio of signal intensity (SIR) of the liver parenchyma and hepatic lesions, the ratio of contrast intensity of the lesion to the liver (CIR), the apparent diŠusion coe‹cients (ADCs) of the liver and lesions, and lesion detectability between pre-and post-contrast images.Results: SIRs, CIRs, and ADC of focal hepatic lesions were comparable on pre-and post-contrast images, and lesion detectability did not diŠer signiˆcantly between pre-and post-contrast T 2 WI and DWI. The SIRs of the liver parenchyma were signiˆcantly lower on post-contrast DWI (1.4±0.68 [b＝500 s/mm 2 ] and 1.71±0.67 [b＝1000 s/mm 2 ]) than pre-contrast images (1.89±0.68 [b＝500 s/mm 2 ] and 2.26±0.78 [b＝1000 s/mm 2 ]) ( Pº 0.001). ADCs of the liver parenchyma were also signiˆcantly decreased on post-contrast DWI (0.77±0.32 mm 2 /s) than pre-contrast images (0.64±0.33 mm 2 /s) ( P＝0.001).Conclusion: T 2 WI and DWI after administration of gadoxetic acid are feasible and do not compromise the SIR, CIR, and ADC of focal hepatic lesions. However, the signal intensity of DWI and ADC value of the liver parenchyma were decreased on gadoxetic acidenhanced hepatocyte phase images.

Intraindividual Crossover Comparison of Gadoxetic Acid Dose for Liver MRI in Normal Volunteers

“…Several researchers have suggested that T 2 -weighted imaging can be performed after gadoxetic acid injection, before the 20-min hepatobiliary as a means to shorten the overall protocol time. [36][37][38][39] Our T 2 measurements confirm that T 2 -weighted imaging after the injection of gadoxetic acid at either 0.025 or 0.05 mmol/kg should have minimal impact on T 2 contrast and can be used to shorten the overall protocol time. Fig.…”

Rules, Roles, and Room for Discussion in Gadoxetic Acid-enhanced Magnetic Resonance Liver Imaging: Current Knowledge and Future Challenges

“…The T 2 * -shortening eŠect does not aŠect the image contrast of the liver on fast spin-echo T 2 -weighted fast spin-echo images and does not decrease tumor conspicuity or sensitivity on T 2 -weighted images. [35][36][37][38][39] This is not true, though, for the bile duct, in which a much higher concentration of excreted gadoxetic acid than in the liver parenchyma leads to a signiˆcant decrease in bile duct signals and degradation of T 2 -weighted MR cholangiopancreatography (MRCP). 40,41 Kim and colleagues, however, reported that post-contrast MRCP is acceptable if obtained within a few minutes of gadoxetic acid injection 42 because excretion of the contrast agent into the bile duct does not start until approximately 5 to 10 min after injection.…”

“…HA is a benign neoplasm composed of hepatocytes and is treated with surgical resection if the HA is considered at high risk for spontaneous hemorrhage or malignant transformation. 30,32,39,58 Recent studies have provided evidence that gadoxetic acid-enhanced MR imaging in general and hepatocyte phase images in particular greatly facilitate the diŠerential diagnosis of these 2 lesions. Most FNHs are strongly enhanced during the arterial phase and show hyperintensity on hepatocyte phase images (Fig.…”

“…35,38,44 Nevertheless, the T 2 * -shortening eŠect of the contrast agent can decrease the signal intensity of the liver parenchyma, which, in turn, may aŠect ADC measurement in the liver parenchyma. 39 …”

Evolution of indeterminate hepatocellular nodules at Gd-EOB-DPTA-enhanced MRI in cirrhotic patients

“…An automated bolus detection algorithm (MR Smart Prep; GE Medical Systems, Milwaukee, WI, USA) or a fluoroscopic triggering (Bolus-Trak; Philips Medical Systems, Best, The Netherlands) was used to obtain an optimal hepatic arterial phase [13]. T2-weighted and DW sequences were obtained between the 3-min late and hepatobiliary phase to reduce the total examination time [14,15]. Other MRI parameters are shown in Table 1.…”