Background: Non-uniformity in signal intensity occurs commonly in magnetic resonance (MR) imaging, which may pose substantial problems when using a 3T scanner. Therefore, image non-uniformity correction is usually app...Background: Non-uniformity in signal intensity occurs commonly in magnetic resonance (MR) imaging, which may pose substantial problems when using a 3T scanner. Therefore, image non-uniformity correction is usually applied. Purpose: To compare the correction effects of the phased-array uniformity enhancement (PURE), a calibration-based image non-uniformity correction method, among three different software versions in 3T Gd-EOB-DTPA-enhanced MR imaging. Material and Methods: Hepatobiliary-phase images of a total of 120 patients who underwent Gd-EOB-DTPA-enhanced MR imaging on the same 3T scanner were analyzed retrospectively. Forty patients each were examined using three software versions (DV25, DV25.1, and DV26). The effects of PURE were compared by visual assessment, histogram analysis of liver signal intensity, evaluation of the spatial distribution of correction effects, and evaluation of quantitative indices of liver parenchymal enhancement. Results: The visual assessment indicated the highest uniformity of PURE-corrected images for DV26, followed by DV25 and DV25.1. Histogram analysis of corrected images demonstrated significantly larger variations in liver signal for DV25.1 than for the other two versions. Although PURE caused a relative increase in pixel values for central and lateral regions, such effects were weaker for DV25.1 than for the other two versions. In the evaluation of quantitative indices of liver parenchymal enhancement, the liver-to-muscle ratio (LMR) was significantly higher for the corrected images than for the uncorrected images, but the liver-to-spleen ratio (LSR) showed no significant differences. For corrected images, the LMR was significantly higher for DV25 and DV26 than for DV25.1, but the LSR showed no significant differences among the three versions. Conclusion: There were differences in the effects of PURE among the three software versions in 3T Gd-EOB-DTPA-enhanced MR imaging. Even if the non-uniformity correction method has the same brand name, correction effects may differ depending on the software version, and these differences may affect visual and quantitative evaluations.展开更多
目的 探讨Gd-EOB-DTPA增强MRI对不伴有周围胆管扩张的肿块型肝内胆管癌(IMCC)中的诊断价值。方法 回顾性分析本院术前行Gd-EOB-DTPA检查术后经病理证实的33例孤立性无周围胆管扩张的IMCC患者的基本MRI征象、动态多期增强强化特征以及肝...目的 探讨Gd-EOB-DTPA增强MRI对不伴有周围胆管扩张的肿块型肝内胆管癌(IMCC)中的诊断价值。方法 回顾性分析本院术前行Gd-EOB-DTPA检查术后经病理证实的33例孤立性无周围胆管扩张的IMCC患者的基本MRI征象、动态多期增强强化特征以及肝胆期(HBP)表现。根据肿瘤动脉期强化特点分为经典型和富血供型,测量并计算HBP病灶及周围肝实质的信号强度(SI)比,对比两型间的差异。结果 33例无周围胆管扩张的IMCC,T2WI以混杂稍高信号为主(26/33,78.8%),伴中央高信号(13/26,50.0%)或低信号区(7/26,26.9%),66.7%(22/33)DWI上呈“靶征”,75.8%(25/33)HBP呈“EOB云”。其中,经典型(n=27)IMCC表现为周边环状强化伴中心渐进性延迟强化;富血供型IMCC(n=6)表现为全瘤(n=2)或近乎全瘤(n=4)强化伴持续性强化(n=5)或廓清(n=1)表现。两型IMCC在慢性乙肝、肝硬化感染率(11.1%vs 66.7%,P=0.011)及肿瘤大小(3.9 cm vs 2.8 cm,P=0.019)具有统计学差异,在伴随征象(肝包膜回缩、DWI靶征、“EOB云”征)、周边廓清及HBP病灶/肝脏SI比(0.67 vs 0.58)无统计学差异(P均>0.05)。结论 无周围胆管扩张的IMCC根据动脉期强化特点分经典型和富血供型,DWI“靶征”及“EOB云”征有助于IMCC的诊断。较经典型IMCC,富血供型IMCC常发生于慢性乙肝、肝硬化背景下,瘤体相对偏小。展开更多
文摘Background: Non-uniformity in signal intensity occurs commonly in magnetic resonance (MR) imaging, which may pose substantial problems when using a 3T scanner. Therefore, image non-uniformity correction is usually applied. Purpose: To compare the correction effects of the phased-array uniformity enhancement (PURE), a calibration-based image non-uniformity correction method, among three different software versions in 3T Gd-EOB-DTPA-enhanced MR imaging. Material and Methods: Hepatobiliary-phase images of a total of 120 patients who underwent Gd-EOB-DTPA-enhanced MR imaging on the same 3T scanner were analyzed retrospectively. Forty patients each were examined using three software versions (DV25, DV25.1, and DV26). The effects of PURE were compared by visual assessment, histogram analysis of liver signal intensity, evaluation of the spatial distribution of correction effects, and evaluation of quantitative indices of liver parenchymal enhancement. Results: The visual assessment indicated the highest uniformity of PURE-corrected images for DV26, followed by DV25 and DV25.1. Histogram analysis of corrected images demonstrated significantly larger variations in liver signal for DV25.1 than for the other two versions. Although PURE caused a relative increase in pixel values for central and lateral regions, such effects were weaker for DV25.1 than for the other two versions. In the evaluation of quantitative indices of liver parenchymal enhancement, the liver-to-muscle ratio (LMR) was significantly higher for the corrected images than for the uncorrected images, but the liver-to-spleen ratio (LSR) showed no significant differences. For corrected images, the LMR was significantly higher for DV25 and DV26 than for DV25.1, but the LSR showed no significant differences among the three versions. Conclusion: There were differences in the effects of PURE among the three software versions in 3T Gd-EOB-DTPA-enhanced MR imaging. Even if the non-uniformity correction method has the same brand name, correction effects may differ depending on the software version, and these differences may affect visual and quantitative evaluations.
文摘目的 探讨Gd-EOB-DTPA增强MRI对不伴有周围胆管扩张的肿块型肝内胆管癌(IMCC)中的诊断价值。方法 回顾性分析本院术前行Gd-EOB-DTPA检查术后经病理证实的33例孤立性无周围胆管扩张的IMCC患者的基本MRI征象、动态多期增强强化特征以及肝胆期(HBP)表现。根据肿瘤动脉期强化特点分为经典型和富血供型,测量并计算HBP病灶及周围肝实质的信号强度(SI)比,对比两型间的差异。结果 33例无周围胆管扩张的IMCC,T2WI以混杂稍高信号为主(26/33,78.8%),伴中央高信号(13/26,50.0%)或低信号区(7/26,26.9%),66.7%(22/33)DWI上呈“靶征”,75.8%(25/33)HBP呈“EOB云”。其中,经典型(n=27)IMCC表现为周边环状强化伴中心渐进性延迟强化;富血供型IMCC(n=6)表现为全瘤(n=2)或近乎全瘤(n=4)强化伴持续性强化(n=5)或廓清(n=1)表现。两型IMCC在慢性乙肝、肝硬化感染率(11.1%vs 66.7%,P=0.011)及肿瘤大小(3.9 cm vs 2.8 cm,P=0.019)具有统计学差异,在伴随征象(肝包膜回缩、DWI靶征、“EOB云”征)、周边廓清及HBP病灶/肝脏SI比(0.67 vs 0.58)无统计学差异(P均>0.05)。结论 无周围胆管扩张的IMCC根据动脉期强化特点分经典型和富血供型,DWI“靶征”及“EOB云”征有助于IMCC的诊断。较经典型IMCC,富血供型IMCC常发生于慢性乙肝、肝硬化背景下,瘤体相对偏小。
