Optimal Pulse Sequence for Ferumoxides-Enhanced MR Imaging Used in the Detection of Hepatocellular Carcinoma: A Comparative Study Using Seven Pulse Sequences

Abstract

ObjectiveTo identify the optimal pulse sequence for ferumoxides-enhanced magnetic resonance (MR) imaging in the detection of hepatocelluar carcinomas (HCCs).Materials and MethodsSixteen patients with 25 HCCs underwent MR imaging following intravenous infusion of ferumoxides. All MR studies were performed on a 1.5-T MR system, using a phased-array coil. Ferumoxides (Feridex IV) at a dose of 15 µmol/Kg was slowly infused intravenously, and axial images of seven sequences were obtained 30 minutes after the end of infusion. The MR protocol included fast spin-echo (FSE) with two echo times (TR3333 8571/TE18 and 90-117), singleshot FSE (SSFSE) with two echo times (TR∞/TE39 and 98), T2*-weighted gradient-recalled acquisition in the steady state (GRASS) (TR216/TE20), T2*-weighted fast multiplanar GRASS (FMPGR) (TR130/TE8.4-9.5), and T2*-weighted fast multiplanar spoiled GRASS (FMPSPGR) (TR130/TE8.4-9.5). Contrast-to-noise ratios (CNRs) of HCCs determined during the imaging sequences formed the basis of quantitative analysis, and images were qualitatively assessed in terms of lesion conspicuity and image artifacts. The diagnostic accuracy of all sequences was assessed using receiver operating characteristic (ROC) analysis.ResultsQuantitative analysis revealed that the CNRs of T2*-weighted FMPGR and T2*-weighted FMPSPGR were significantly higher than those of the other sequences, while qualitative analysis showed that image artifacts were prominent at T2*-weighted GRASS imaging. Lesion conspicuity was statistically significantly less clear at SSFSE imaging. In term of lesion detection, T2*-weighted FMPGR, T2*-weighted FMPSPGR, and proton density FSE imaging were statistically superior to the others.ConclusionT2*-weighted FMPGR, T2*-weighted FMPSPGR, and proton density FSE appear to be the optimal pulse sequences for ferumoxides-enhanced MR imaging in the detection of HCCs.

Detection and characterization of liver metastases: 16--slice multidetector computed tomography versus superparamagnetic iron oxide-enhanced magnetic resonance imaging

“…The higher capability of SPIO-enhanced MR imaging in differentiating between hepatic metastases or hepatic cysts might be attributable to the use of two kinds of SPIO-enhanced imaging, that is, unenhanced and SPIO-enhanced T2-weighted TSE sequences facilitate the differentiation between hepatic metastases and hepatic cysts, as well as lesion detection, although the T2*-weighted GRE sequence was used only for lesion detection, as the sequence which provides the highest degree of lesion-liver contrast [28,29]. Three small hepatic metastases (0.4 cm, 0.5 cm, 0.7 cm) were misinterpreted as hepatic cysts on MDCT commonly by both observers, because all of them mimicked hepatic cysts, showing well-defined clear low attenuation on the portal venous phase, without rim enhancement.…”

“…b SPIOenhanced respiratory-triggered T2-weighted turbo-spin echo image shows a slightly high signal intensity mass (arrow) at the same location as in a, which was correctly interpreted as a malignant mass by the two reviewers maximum lesion-to-liver contrast. The T2*-weighted gradient-recalled echo technique has been generally considered to be the optimal pulse sequence, due to its greater susceptibility, the result of local field inhomogeneities [28,29]. For the MDCT imaging, three-phasic dynamic images, including arterial, portal venous, and equilibrium phases, were acquired at 3 mm reconstruction thickness, using a detector collimation of 1.5 mm.…”

Detection of hepatocellular carcinoma: comparison of ferumoxides-enhanced and gadolinium-enhanced dynamic three-dimensional volume interpolated breath-hold MR imaging

“…However, all of the lesions we detected were subjected to several confirming studies, such as CT hepatic arteriography, CT during arterial portography or CT after arterial infusion of iodized oil [31,32] and at least 6-month follow-up studies, all of which should support the present study results. Second, we did not include T1-weighted images when we evaluated the diagnostic accuracy of ferumoxidesenhanced MR images because T2-weighted and T2*-weighted images have been regarded as the two best sequences for revealing SPIO-induced signal decrease [15,16]. However, considering that ferumoxides-enhanced T1-weighted images could be helpful to avoid false positive diagnosis, interpretation of ferumoxides-enhanced T2-weighted and T2*-weighted images may result in underestimation of diagnostic accuracy of ferumoxidesenhanced MRI for detection of HCC.…”

“…Respiratory-triggered T2-weighted turbo spin-echo imaging was obtained using the following parameters: a TR/TE of 3,300-5,500/85, echo train length of 5, matrix of 120×256 and a signal average of two. Breath-hold T2*-weighted FISP imaging was obtained using the following parameters: a TR/TE of 180/12, 30°flip angle, matrix of 96×256 and a signal average of one [15,16]. Breath-hold T1-weighted fast low-angle shot imaging was obtained using the following parameters: a TR/TE of 120/4, 70°flip angle, matrix of 120×256 and a signal average of one.…”

MRI in the Evaluation of Hepatocellular Nodules: Role of Pulse Sequences and Contrast Agents

“…10). Fast gradient-echo T1W sequence with a long TE (time of echo) (8-10 ms) can provide excellent image quality with a sufficient susceptibility effect [33]. Since image contrast obtained with this sequence is generated based on a balance of T1 and T2 relaxation, the unenhanced MR images have only poor image contrast.…”