DWI在肝硬化癌前病变鉴别诊断中的临床价值

目的 探讨核磁共振弥散加权成像(DWI)技术ADC值在肝硬化再生结(RN)、癌前病变(DN)、早癌及原发性小肝癌(SHCC)的鉴别诊断中价值.方法 采用ADC值测定结合容积采集技术LAVA动态扫描,在228例肝硬化患者中,再生结节性(RN)患者121例,DN结节9例,原发性肝癌98例,其中小肝癌(SHCC)及早期小癌(ESHCC)21例;正常组90例;测定ADC值的演变过程.结果 本研究鉴别诊断RN结节、DN结节、HCC的检出率分别为45.15％、3.36％、36.57％,其中SHCC及ESHCC的检出率7.84％.测定RN结节的ADC值为(2.0±0.22)×10-3 mm2/s、DN结节的ADC值为(1.50±0.27)×10-3 mm2/s,演变为SHCC或ESHCC时其ADC值下降为(1.17±0.19)× 10-3 mm2/s.结论 随着肝硬化-再生结节-癌前结节-肝癌的病理演变过程,其ADC值呈逐渐下降趋势,各组ADC均值存在显著性差异(P＜0.05),DWI技术可以对肝硬化各个阶段病变进行较为准确可信的判断.     

基于钆塞酸二钠增强MRI高度异型增生结节分类对2018版LI-RADS诊断效能的影响

目的 在肝细胞癌(HCC)高危因素背景下，探讨基于钆塞酸二钠(Gd-EOB-DTPA)增强MRI高度异型增生结节(HGDN)分类处理对2018版肝脏影像报告与数据系统(LI-RADS)诊断效能的影响。方法 回顾性分析2015年1月至2021年12月在桂林医学院附属医院放射科，行Gd-EOB-DTPA增强MRI检查并术后经病理诊断的169例HCC高风险患者，共192个肝结节。两名放射科医师独立评估患者的影像征象，根据2018版LI-RADS分类标准将结节分类，统计分析LR-4/5、LR-5的诊断效能。为HGDN增加一个新分类LR-DN,将病理结果为HGDN的结节分类为LR-DN,其他结节分类不变，重新统计LR-4/5、LR-5的诊断效能。结果 2018版LI-RADS分类LR-4/5、LR-5的灵敏度、特异度、准确率分别为92.81%、56.41%、85.42%和82.35%、79.49%、81.77%。新增LR-DN分类后，LR-4/5、LR-5的灵敏度无变化，特异度分别为87.18%、92.31%,准确率分别为91.67%、84.38%。结论 Gd-EOB-DTPA增强MRI结合20...     

3D T1WI/TFE序列在肝硬化增生结节诊断中的应用

目的：探讨MRI中三维T1加权成像梯度回波(3DT1WI／TFE)序列在肝硬化结节诊断中的价值。方法：对临床疑肝硬化和／或经Cr及超声检查后诊断为肝硬化33例进行MRI3DT1WI／TFE序列扫描检查，分析肝硬化结节在该序列中的特点。结果：33例中，无增生结节的肝硬化7例，肝硬化合并增生结节6例，肝硬化并肝癌20例。肝硬化结节在3DT1WI／TFE上呈高信号，在T2WI上呈低信号，在静脉动态增强中肝硬化结节与正常肝实质同步强化。而肝硬化并肝癌在3DT1WI／TFE上呈低信号，在T2WI上呈高信号，在静脉动态增强中表现为“快进快出”的特性。结论：MRI中3DT1WI／TFE序列在肝硬化检查中，能很好的显示肝内增生结节，并且可与结节性肝癌进行鉴别。图像质量高，能够满足临床的诊断需要。     

肝硬化结节与小肝癌的MRI研究

目的:回顾性分析肝硬化合并小肝癌、再生结节(RN)及肝不典型增生结节(DN)的MR表现,探讨其MR诊断与鉴别诊断。方法:收集50例结节性肝硬化病例MR检查资料,患者行正反相位T1WI、脂肪抑制T2WI、动态增强扫描和弥散加权(DWI)扫描,总结肝内结节的信号特点。结果:RN在T1WI脂肪抑制上多为等信号或稍高信号,T2WI多为低信号,增强后与周围正常肝组织强化相似或信号稍低;DN在T1WI多为较高信号,T2WI多为稍低或等信号,增强后强化不明显;癌结节T1WI多为稍低或等信号,偶有稍高信号,T2WI多为较高信号,DWI为高信号,强化多为动脉中晚期强化,门静脉期以后强化减退。结论:磁共振平扫加动态增强能对大多数RN、DN和小肝癌结节做出明确诊断和鉴别。     

肝硬化再生结节和退变结节的MRI表现：初步研究结果

目的研究肝硬化再生结节和退变结节的MRI表现.资料与方法前瞻性地研究26例肝硬化再生结节和退变结节的MRI表现,其中合并肝癌8例.26例中有12例行CT平扫,6例行CT增强扫描;26例均行MRI平扫,18例行Gd-DTPA增强MRI,10例行超顺磁性氧化铁(菲立磁)增强MVI.临床实验室检查中,除8例合并有肝癌的患者甲胎蛋白显著增高外,其余18例甲胎蛋白均正常.结果26例中12例结节灶直径＜1 cm，8例在1～3 cm，6例＞3 cm.MRI表现：12例直径＜1 cm的结节灶在T1WI呈等信号，T2WI呈低信号，Gd-DTPA和菲立磁增强与正常肝实质呈同步强化，在CT上呈高密度改变.结节灶直径1～3 cm的8例中,5例结节在T1WI呈高信号,T2WI呈低信号,强化同前;另3例在T1WI呈低信号的结节,在T2WI呈高信号,其强化与正常肝实质不同步,在菲立磁增强扫描中呈高信号;CT平扫均呈等密度.6例直径＞3 cm的结节中2例在T1WI、T2WI均呈等高信号,菲立磁增强扫描呈高信号,Gd-DTPA增强MRI示巨大结节较周围邻近正常肝组织信号高;4例在T1WI呈高信号,在T2WI呈低信号，菲立磁增强扫描呈低信号,Gd-DTPA增强扫描巨大结节无强化，较周围邻近正常肝组织信号低,有时可见血管经过巨大结节表面.CT显示6例呈等或稍高密度.在MRI上可见1例“结中结”征.结论肝硬化再生结节在MRI上能较好地与肝细胞癌鉴别,但较难与退变结节鉴别.退变结节在T2WI不呈高信号,而肝细胞癌呈高信号,以此可作区别.此外,良性退变结节菲立磁增强T2WI呈低信号.     

MRI对前列腺中央腺体T2WI低信号结节的良恶性分析

目的:探讨前列腺中央腺体T2WI低信号良、恶性结节的MRI表现,以提高鉴剐诊断的能力.方法:符合纳入标准的19例前列腺癌结节和61例前列腺增生患者经多序列MRI检查并经组织病理学证实.对两者在T2WI上的信号和边缘.DWI信号强度和ADC值、及多期DCE的最大信号强度和时间信号强度曲线的类型进行比较分析.结果:19例前列腺癌结节T2WI上边界不清、部分不清16例,边缘清楚3例,呈均质低信号;61例前列腺增生结节边缘不清及部分边界不清共34例,边缘清楚27例,信号均匀30例,信号不均匀31例.两者具有显著性的差异(P=0.007).于DWI,前列腺癌结节信号强度(b值为800 s/mm2)为60.6±10.7明显高于增生结节(49.7±8.5)(t值为 5.793,P=0.00).前列腺癌结节ADC值为(0.83±0.18)×10-3mm2/s,明显高于增生结节(1.17±0.24mm2/s)(t值为0.4 60,P=0.00).多期DCE,前列腺癌的最大信号强度为385.60±108.27,增生结节的最大信号强度为393.21±111.28(t值为-0.270,P=0.788),两者比较没有显著性差异.前列腺癌时间信号强度曲线以速升速降为主,而增生结节以渐进型和速升平台型为主,两者具有显著性差异(P=0.00);其中速升速降型和渐进型曲线于组间具有显著性差异).结论:前列腺中央叶T2WI低信号结节中,前列腺癌与前列腺增生于T2 WI边缘和信号均匀性、DWI的信号强度和ADC值、曲线类型均有差异.故MRI多序列成像分析助于对中央腺体T2WI低信号结节良恶性的鉴别诊断.     

肝硬化结节自然病程的磁共振功能成像研究进展

肝硬化结节性病变经过肝硬化再生结节(RN)、低级别退变结节(DN)、高级别DN、DN癌变,最终演变成小肝癌.鉴别肝硬化结节病变病程的不同阶段对临床早期检测癌变结节,进行早期干预、提高病人生存率具有重要意义.介绍肝脏RN、DN及其癌变结节病理学特点及常规MRI影像学特点,并着重对磁共振功能成像的原理及其在肝硬化结节的应用现状及前景予以综述.     

肝硬化结节自然病程的磁共振功能成像研究进展

肝硬化结节性病变经过肝硬化再生结节(RN)、低级别退变结节(DN)、高级别DN、DN癌变,最终演变成小肝癌.鉴别肝硬化结节病变病程的不同阶段对临床早期检测癌变结节,进行早期干预、提高病人生存率具有重要意义.介绍肝脏RN、DN及其癌变结节病理学特点及常规MRI影像学特点,并着重对磁共振功能成像的原理及其在肝硬化结节的应用现状及前景予以综述.     

原发性肝细胞癌癌前病变血液动力学的MR实验研究

目的探讨原发性肝细胞癌(HCC)癌前病变血液动力学的特征。方法用MR灌注扫描(MR perfusion,MRP)的方法对实验诱发大鼠肝脏的HCC癌前病变阶段到癌变阶段的血液动力学进行动态观察。结果在MR T2WI检出并与病理对应良好的46个结节中有9个再生结节(regenerative nodule,RN)、22个HCC癌前病变即发育不良结节(dysplastic nodule,DN)、10个早期HCC和5个HCC。RN、DN、早期HCC和HCC结节及邻近肝实质的平均阳性强化积分值(positiveenhancement integral,PEI)分别为205·67±31·17、161·94±20·74、226·09±34·83、491·86±44·61、204·84±70·19。将结节PEI值和结节旁肝组织PEI值对比,发现9个RN与邻近肝实质差异无统计学意义(t=-5·30,P=0·06),MRP图像的动脉期和门脉期RN均呈等信号;DN较邻近肝实质低,并有统计学意义(t=-3·64,P=0·02),DN的血流灌注曲线于动脉后期较邻近肝实质下降,MRP图像动脉期呈等信号,门脉期为低信号。10个早期HCC中4个结节表现为低灌注,PEI值低于邻近肝实质,动脉期呈稍低信号,门脉期为等信号;6个早期HCC显示为稍高灌注,PEI值稍高于邻近肝实质,动脉期为稍高信号,门脉期呈稍低信号。5个HCC呈典型的动脉期明显强化、门脉期呈相对低信号,结节灌注曲线动脉段较邻近肝实质有明显抬高,结节较邻近肝实质的PEI明显增大,差异有统计学意义(t=3·74,P=0·02)。结论MRP能反映HCC癌前病变结节演变过程中血流的改变,HCC的血流灌注量较邻近肝实质明显增多;DN的血流灌注量较邻近肝实质减少。     

PWI在肝硬化增生性结节诊断中的应用

目的 :探讨PWI在肝硬化增生性结节(dysplastic nodule,DN)诊断中的应用。方法 :回顾性分析经病理证实的40例DN患者的PWI资料,获得每个DN的时间-信号强度曲线(time intensity curve,TIC)和峰值时间(time to peak,TTP),计算肝脏动脉灌注指数(hepatic perfusion index,HPI)。结果:28例28个DN为低级别DN(low grade DN,LGDN),TIC主要呈缓升缓降型20个,TTP为(41.56±1.67)s,HPI为0.27±0.04;12例14个DN为高级别DN(high grade DN,HGDN),TIC主要呈速升缓降型11个,TTP为(39.81±2.36)s,HPI为0.45±0.06。结论:PWI能客观地反映DN的血流情况,有助于DN的诊断和鉴别诊断。     

肝硬化结节与小肝癌的CT、MRI诊断

在肝硬化结节及小肝癌的早期诊断方面,CT、MRI仍是目前临床工作中最重要的方法,本文阐述肝硬化结节演变为肝癌过程中的几个重要环节的CT、MRI表现及国内、外对此的研究现状,这几个环节包括肝硬化再生结节、发育不良性结节(低、中、高级)、小肝癌及肝癌,它们在CT、MRI表现上各有特征,但相互间也有影像学表现上的重叠,故多数较典型者可以通过CT密度值、MRI信号值及增强表现判断其性质,少部分诊断有困难的病灶可以通过双动脉期扫描、MR菲立磁增强及灌注成像等方法提供更多的诊断信息。     

Stepwise carcinogenesis of hepatocellular carcinoma in the cirrhotic liver: demonstration on serial MR imaging

PURPOSE: To demonstrate imaging findings of stepwise carcinogenesis of hepatocellular carcinoma (HCC) in cirrhosis at serial state-of-the-art MR imaging exams. MATERIALS AND METHODS: In a retrospective search of the hospital archives, three patients were identified in which developing HCC was observed in serial MR examinations, with histopathology or alpha-fetoprotein (AFP) correlation. Image findings were assessed for signal intensity of the lesions at multiple sequences, including dynamic gadolinium-enhanced imaging. RESULTS: Initial findings in patient A showed a small nodule with fatty infiltration that developed in HCC in follow-up MRI, comprised of low-grade dysplastic nodule (DN; DN I), high-grade DN (DN II), and eventually classic HCC. In patient B, increased signal intensity on T2-weighted images in a single DN among numerous regenerative nodules was the only initial sign. Follow up MRI showed further increase in signal intensity and increased neovascularity, which suggested focal HCC in a DN II. Patient C demonstrated gradually increasing neovascularity as only initial sign, with development of classic HCC over time. CONCLUSION: MR imaging provides insight in various pathways of stepwise carcinogenesis of developing HCC in cirrhosis. This may further explain the genetic heterogeneity, and may facilitate early detection and better selection of patients for follow-up.     

Characterization of hyperintense nodules on precontrast T1-weighted MRI: utility of gadoxetic acid-enhanced hepatocyte-phase imaging

Purpose:

To evaluate the utility of gadoxetic acid‐enhanced hepatocyte‐phase magnetic resonance imaging (MRI) in characterization of T1‐weighted hyperintense nodules within cirrhotic liver.

Materials and Methods:

This retrospective study was approved by our Institutional Review Board. Thirty‐four nodules hyperintense in unenhanced T1‐weighted MRI with histopathological confirmation from a collection of 19 patients were included. Tumor size, signal intensity on T1‐weighted, and T2‐weighted imaging as well as enhancement patterns on contrast‐enhanced dynamic/hepatocyte‐phase imaging were recorded. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of hepatocyte‐phase imaging.

Results:

Evaluation of the nodules with standard of reference revealed 15 dysplastic nodules (DN), seven well‐differentiated hepatocellular carcinomas (wHCC), and 12 moderately differentiated HCCs (mHCC). The mean size of dysplastic nodules was smaller than that of HCCs (P < 0.001). Using the HCC criteria (T2W or arterial enhancement followed with portal venous washout), 11/19 HCC were correctly characterized. Using solely hypointensity (compared to the surrounding liver parenchyma) during the hepatocyte phase as the criterion, 18/19 HCC were correctly characterized. There were seven additional HCCs diagnosed with hepatocyte‐phase imaging (P = 0.02).

Conclusion:

Gadoxetic acid‐enhanced MRI with hepatocyte‐phase imaging is superior to gadoxetic acid‐enhanced MRI with conventional criteria alone in characterization of T1W hyperintense nodules. J. Magn. Reson. Imaging 2011;33:625–632. © 2011 Wiley‐Liss, Inc.     

Benign versus malignant hepatic nodules: MR imaging findings with pathologic correlation.

According to the currently used nomenclature, there are only two types of hepatocellular nodular lesions: regenerative lesions and dysplastic or neoplastic lesions. Regenerative nodules include monoacinar regenerative nodules, multiacinar regenerative nodules, cirrhotic nodules, segmental or lobar hyperplasia, and focal nodular hyperplasia. Dysplastic or neoplastic nodules include hepatocellular adenoma, dysplastic foci, dysplastic nodules, and hepatocellular carcinoma (HCC). Many of these types of hepatic nodules play a role in the de novo and stepwise carcinogenesis of HCC, which comprises the following steps: regenerative nodule, low-grade dysplastic nodule, high-grade dysplastic nodule, small HCC, and large HCC. State-of-the-art magnetic resonance (MR) imaging facilitates detection and characterization in most cases of hepatic nodules. State-of-the-art MR imaging includes single-shot fast spin-echo imaging, in-phase and opposed-phase T1-weighted gradient-echo imaging, T2-weighted fast spin-echo imaging with fat saturation, and two-dimensional or three-dimensional dynamic multiphase contrast material-enhanced imaging.     

Differentiation of well‐differentiated hepatocellular carcinomas from other hepatocellular nodules in cirrhotic liver: Value of SPIO‐enhanced MR imaging at 3.0 Tesla

Purpose

To determine the diagnostic value of superparamagnetic iron oxide (SPIO)‐enhanced MRI for the differentiation of well‐differentiated hepatocellular carcinomas (WD‐HCCs) from other hepatocellular nodules in cirrhotic liver.

Materials and Methods

This study included 114 patients with 216 histologically confirmed hepatocellular nodules, i.e., 23 dysplastic nodules (DNs), 37 WD‐HCCs, and 156 moderately or poorly differentiated HCCs (MD‐/PD HCCs), who underwent SPIO‐enhanced MRI at 3.0T. MRI included T2‐weighted fast‐spin echo and T2*‐weighted gradient recalled echo (GRE) sequences before and after administration of ferucarbotran. The contrast‐to‐noise ratio (CNR) of the lesion was calculated. Reviewers analyzed signal intensity (SI) of the nodules and their enhancement features on SPIO‐enhanced images. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in the diagnosis of WD‐HCC were also calculated.

Results

The mean CNR of WD‐HCC was significantly higher than that of DN on T2*‐weighted image. Incomplete high SI on SPIO‐enhanced T2*‐weighted images were seen in 56.8% of WD‐HCC. The most prevalent enhancement features of WD‐HCCs on SPIO‐enhanced T2*‐weighted images, were iso SI with high SI foci [32.5% (12/37)] and homogenous subtle high SI [24.3% (9/37)]. Alternatively, 22 of 23 DNs (95.7%) showed low‐ or iso SI, and 145 of 156 (94.9%) MD‐/PD HCCs showed strong high SI. When iso SI with high SI foci or subtle homogenous high SI nodule was considered as diagnostic criteria for WD‐HCC, we could identify 56.8% of the WD‐HCCs but only 4.4% of the DNs and 3.2% of the MD‐/PD HCCs.

Conclusion

WD‐HCCs have characteristic enhancement features that differentiate them from DNs and MD‐/PD HCCs on SPIO‐enhanced 3.0T MRI. The lesion conspicuity was better on T2*‐weighted images than that on T2‐weighted images. J. Magn. Reson. Imaging 2009;29:328–335. © 2009 Wiley‐Liss, Inc.     

Method for simultaneous voxel-based morphometry of the brain and cervical spinal cord area measurements using 3D-MDEFT

Purpose:

To develop a quantitative multiparametric PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) magnetic resonance imaging (MRI) approach and its application in a diethylnitrosamine (DEN) chemically induced rodent model of hepatocarcinogenesis for lesion characterization.

Materials and Methods:

In nine rats with 33 cirrhosis‐associated hepatic nodules including regenerative nodule (RN), dysplastic nodule (DN), hepatocellular carcinoma (HCC), and cyst, multiparametric PROPELLER MRI (diffusion‐weighted, T2/M0 (proton density) mapping and T1‐weighted) were performed. Apparent diffusion coefficient (ADC) maps, T2 and M0 maps of each tumor were generated. We compared ADC, T2, and M0 measurements for each type of hepatic nodule, confirmed at histopathology.

Results:

PROPELLER images and resultant parametric maps were inherently coregistered without image distortion or motion artifacts. All types of hepatic nodules demonstrated complex imaging characteristics within conventional T1‐ and T2‐weighted images. Quantitatively, cysts were distinguished from RN, DN, and HCC with significantly higher ADC and T2; however, there was no significant difference of ADC and T2 between HCC, DN, and RN. Mean tumor M0 values of HCC were significantly higher than those of DN, RN, and cysts.

Conclusion:

This study exploited quantitative PROPELLER MRI and multidimensional analysis approaches in an attempt to differentiate hepatic nodules in the DEN rodent model of hepatocarcinogenesis. This method offers great potential for parallel parameterization during noninvasive interrogation of hepatic tissue properties. J. Magn. Reson. Imaging 2010;31:1242–1251. © 2010 Wiley‐Liss, Inc.     

肝再生性结节的MRI诊断

目的:总结肝再生性结节(RN)的MRI平扫及动态增强的表现,以与其它结节进行鉴别.方法:搜集行Gd-DTPA动态增强磁共振检查的RN病例共30例,全部病例均经手术切除病理或穿刺活检证实.MRI均行平扫、动态增强及延迟增强扫描,分析结节的信号特征及动态增强曲线.结果:肝再生性结节包括弥漫分布的小结节18例(铁质沉着性结节6例和非铁质沉着性结节12例)和大结节12例17个病灶.铁质沉着性结节在增强各期均无强化,时间-信号强度曲线较平直;大部分非铁质沉着性结节在T1WI上和T2WI上均为中等信号,周围纤维间隔为偏低信号,动态及延迟增强扫描结节轻度强化,时间-信号强度曲线与正常肝组织类似.本组所选大结节为直径大于0.5 cm、T1WI高信号、T2WI低信号的病灶,其中10个病灶(占58.8%)在T1W/WATS上信号高于T1W/IP.动态增强各期病灶无明显强化,时间-信号强度曲线显示病灶的曲线为缓慢上升型.结论:肝再生性结节有不同类型及表现形式,其中孤立的大结节型RN需与肝内其它结节鉴别.     

Hepatocellular carcinoma: association with increased iron deposition in the cirrhotic liver at MR imaging.

PURPOSE: To determine whether the frequency of hepatocellular carcinoma (HCC) in patients with cirrhosis is affected by hepatic iron deposition as detected with magnetic resonance (MR) imaging. MATERIALS AND METHODS: In a retrospective search of MR imaging and histopathology records, 196 patients with histopathologically proved cirrhosis and with (n = 80) or without (n = 116) HCC who underwent T2-weighted conventional or fast spin-echo and gradient-echo (GRE) (echo time > or = 6.0 msec) imaging were identified. MR images were qualitatively and quantitatively evaluated for diffuse hepatic iron deposition and siderotic regenerative nodules to assess their correlation with the presence of HCC. RESULTS: Hepatic parenchymal iron deposition was seen in 79 (40%) patients, and iron deposition in regenerative nodules was seen in 71 (36%) at MR imaging. The mean signal intensity ratio of GRE images in patients with hepatic iron deposition was significantly lower than that in patients without it (P < .001). The frequency of HCC in patients with iron deposition in regenerative nodules (52% [37 of 71 patients]) was significantly higher (P = .015) than that in patients without iron in regenerative nodules (34% [43 of 125 patients]). CONCLUSION: The occurrence of HCC may be associated causally with iron deposition in regenerative nodules in patients with cirrhosis. MR imaging can enable detection of iron deposition in regenerative nodules as a possible risk factor for the development of HCC.     

Siderotic nodules at MR imaging: regenerative or dysplastic?

OBJECTIVE: To determine if iron containing "siderotic" nodules detected at magnetic resonance (MR) imaging are regenerative (RN) or dysplastic (DN) and to attempt to identify features that may distinguish them. MATERIAL AND METHODS: MR imaging (1.5 T) was performed on 77 cirrhotic patients who underwent orthotopic liver transplantation within 0-117 days (mean 30 days) of MR imaging. Two readers retrospectively evaluated breath-hold gradient-echo pulse sequences (echo time > or =9.0 ms, flip angle < or =45 degrees) for the presence of hypointense nodules, which were classified as micronodular (< or =3 mm), macronodular (>3 mm), or mixed. Nodule distribution was classified as focal (<5), scattered (5-20), or diffuse (>20) per slice. Thin section pathologic correlation was available in all cases, and Prussian blue iron stains were performed. RESULTS: Of 35 patients with pathologically proven siderotic nodules, 10 (29%) had at least 2 siderotic DN. MR detected siderotic nodules in 10 of 10 (100%) patients with siderotic DN and RN, and in 18 of 25 patients (72%) with siderotic RN only. CONCLUSION: Siderotic RN cannot be reliably distinguished from siderotic DN with MR imaging, and therefore the widely used term "siderotic regenerative nodule" should be avoided and replaced by "siderotic nodule."