肾嗜酸细胞腺瘤的影像学诊断

目的:探讨螺旋CT和MRI对肾嗜酸性细胞腺瘤的诊断及鉴别诊断的价值。方法:回顾性分析12例肾嗜酸性细胞瘤的CT和/或MRI表现。结果:CT检查12例,平扫8例病灶呈均匀软组织密度影,3例呈不均匀软组织密度影,1例瘤体周边有环状钙化。增强后病灶轻中度强化,6例见星状瘢痕。MRI检查3例,2例T1WI呈等低信号、T2WI呈高信号;1例T1WI呈等信号、T2WI等低信号。结论:多数肾嗜酸细胞腺瘤的影像学表现具有一定特征性。CT结合MRI特别是动态扫描有助于术前做出正确的诊断。     

肾嗜酸细胞腺瘤的影像学诊断

目的：探讨螺旋CT和MRI对肾嗜酸性细胞腺瘤的诊断及鉴别诊断的价值。方法：回顾性分析12例肾嗜酸性细胞瘤的CT和／或MRI表现。结果：CT检查12例,平扫8例病灶呈均匀软组织密度影,3例呈不均匀软组织密度影,1例瘤体周边有环状钙化。增强后病灶轻中度强化,6例见星状瘢痕。MRI检查3例,2例T1WI呈等低信号、T2WI呈高信号;1例T1wI呈等信号、T2WI等低信号。结论：多数肾嗜酸细胞腺瘤的影像学表现具有一定特征性。CT结合MRI特别是动态扫描有助于术前做出正确的诊断。     

MRI 在脊柱骨巨细胞瘤诊疗中的临床意义

目的:探讨MRI在脊柱骨巨细胞瘤诊疗中的临床应用价值。方法:回顾性分析2005年4月-2010年11月我院5例经病理证实为脊柱骨巨细胞瘤患者的MRI检查表现。结果:椎体内病灶呈不同程度膨胀性破坏,T1WI呈等、低信号改变,T2WI呈混杂信号,增强扫描呈不同程度均匀强化。结论:MRI能有效显示骨巨细胞瘤的病变部位及范围,。     

头颈部木村病的CT、MRI影像学表现

目的:探讨头颈部木村病的CT、MRI的影像学表现。方法:对6例经手术或活检病理证实的头颈部木村病的CT及MRI影像学表现进行回顾性分析。结果:本组6例以中青年男性患者多见,病灶位于耳周2例、颊面部1例、颌下区1例,腮腺区1例、头皮下1例,均表现为无痛性肿块。3例CT表现为单侧或双侧、单发或多发等或略高密度软组织肿块,密度均或不均,边缘清楚或局部欠清,伴邻近皮下组织受累;增强扫描病灶表现为不同程度强化。3例MRI表现为对比邻近肌肉信号,病灶在T1WI上为等、稍高信号,在T2WI上为高信号,大部分病灶中等至明显强化。本组6例病变均伴有周围多发淋巴结肿大及实验室检查外周血嗜酸性粒细胞增多,可伴病侧局部皮下脂肪层萎缩。结论:头颈部木村病的CT、MRI影像表现有一定特征性,结合临床病史及实验室检查,可提高木村病的诊断准确率。     

强直性脊柱炎骶髂关节CT MRI表现

目的 :旨在评估强直性脊柱炎 (AS)患者骶髂关节炎的MR影像学特征。并比较X线平片、CT和MR影像在诊断骶髂关节炎中的作用。方法 :搜集 1 2例AS患者 ,分别行X线平片、CT和MR检查。增强前MR扫描序列包括SET1 W1 、FSET2 WI和梯度回波的准T2 (GRT2 WI)。增强后MR扫描序列参数与增强前SET2 WI相同。另选 9例志愿者 ,行MR平扫检查。结果 :8例志愿者 1 6个骶髂关节的T1 WI和T2 WI可直接显示正常骶髂关节软骨表现为线形或点样的中等信号影。 9例志愿者 1 1个骶髂关节的骨髓内可见局灶性脂肪沉积。 1 2例AS患者 2 1个骶髂关节可见软骨异常 ,表现为T1 WI和T2 WI上正常线形中等信号的软骨影像消失代之以不规则增粗或扭曲样中等信号。患者组CT表现为Ⅱ～Ⅳ级骶髂关节炎 ,即关节软骨下骨板硬化 ,侵蚀囊变 ,关节间隙宽窄不均或部分强直 ,韧带部受累。分析表明 :在骶髂关节炎的诊断方面 ,MR和CT明显优于X线平片 (P <0 .0 0 1 )。结论 :同X线片比较虽CT和MRI均有助于AS骶髂关节炎的诊断 ,但MR影像可显示CT和X线所不能显示的软骨异常和骨髓内水肿改变 ;骨髓内脂肪沉积可属正常变异 ,扭曲样中等强度信号应视为软骨的异常征象。     

原发性骨恶性纤维组织细胞瘤24例临床特征及预后分析

摘要 目的：总结原发性骨恶性纤维组织细胞瘤（PBMFH）的临床特征和预后。方法：回顾性分析我院2000年10月至2011年1月收治的24例PBMFH患者的术前影像学资料、诊断依据、治疗方案和随访资料。结果：24例患者全部通过术后病理确诊,穿刺准确率为75.00%.胸部X线检查结果显示：2例发现肺部转移灶,22例未发现肺部转移灶。肿瘤局部X线检查结果显示：3例出现骨质溶解性破坏,1例出现肿块影,20例表现为骨膜反应。MRI检查结果显示：4例MRI检查肿瘤局部情况时发现3例T1WI等信号、T2WI稍高信号,1例T1WI低信号、T2WI低信号。本研究中行放化疗18例,有6例（33.33%）发生转移,转移时间为6~45个月,中位转移时间为（25.30±6.24）个月,单纯手术治疗6例中有5例发生转移（83.33%）,转移发生时间为3~6月,中位转移时间为（5.00±0.24）个月。结论：PBMFH患者单纯手术出现转移多发生于术后5月,根治性手术辅以放化疗出现转移多发生于术后25月。由此可见,术前穿刺活检病理有助于疾病诊断,术后辅助化疗有助于降低PBMFH的复发率和转移率。     

胰腺神经内分泌肿瘤的不典型CT、MRI征象分析

目的:分析4例胰腺神经内分泌肿瘤(P-NENs)的不典型CT、MRI影像学特征,以提高对其诊断水平.方法:对4例经手术病理证实的P-NENs的不典型CT和(或)MRI表现进行回顾性分析.结果:4例胰腺神经内分泌肿瘤患者均进行CT平扫及增强检查,平扫病变相对于正常胰腺呈等密度1例,稍低密度3例,其中1例瘤内见钙化;CT增强扫描4例均为轻～中度增强,静脉期较动脉期增强幅度稍减低,所有患者各期增强幅度均未超过胰腺实质,其中1例可见延迟期不完整包膜强化,包膜密度略高于周围胰腺.3例患者行MRI平扫、DWI及增强检查,2例肿瘤相对正常胰腺呈长T1、稍长T2信号,较均匀,1例T1WI呈不均匀稍低信号,T2WI呈较高与稍低混杂信号,CT所显示之病变内钙化T1、T2均呈较低信号.DWI序列3例病变均呈较明显高信号.增强扫描3例病变均呈轻到中度强化,2例强化较均匀,1例强化不均匀,强化幅度均未超过正常胰腺.2例MRI可见有部分包膜环形强化,略高于周围胰腺实质.结论:明显增强以及包膜强化被认为是P-NENs的典型影像学表现,但其影像学表现多样,认识其多样性及不典型影像学征象,可以提高对其诊断准确率.     

肩关节原始神经外胚层肿瘤1例

原始神经外胚层肿瘤分为中枢性和外周性两类,是起源于原始神经管胚基细胞的未分化的高度恶性的肿瘤。外周性原始神经外胚层肿瘤源于神经嵴,可发生在骨、软组织,生长在盆腔、腹腔、腹膜后、肺及胸壁的肿瘤也有报道。发生于骨关节的PNET以青壮年多见,女性多于男性,病程1年以内,以局部疼痛伴软组织肿块为特点,软组织肿块内囊变或钙化少见;可发生于长骨及扁骨,其中肱骨好发。骨骼以溶骨性为主要表现,少见肿瘤骨。病理以镜下可见H-W菊形团结构,免疫组化染色Vim、CD99强阳性为特点。本例为女性患者,影像学特点以右肩关节周围软组织肿块及肩胛骨溶骨性破坏为主。肿块内未见肿瘤骨及明显骨膜反应。CT扫描肿瘤的分界欠清,对邻近组织侵袭性不强。MRI扫描可见肿瘤等信号为主,T2WI肿瘤内部可见片状高信号影。由于PNET恶性程度高,当肿瘤发生于骨内,需要与尤文氏肉瘤(EW)鉴别。     

颅内原发性黑色素瘤的影像学诊断

目的：探讨颅内黑色素瘤的影像学特点。方法：回顾性分析5例经手术病理及临床证实的颅内原发性黑色素瘤的CT和MR影像学表现。结果：CT表现为类圆形高密度影4例,低密度影1例。增强扫描肿瘤出现不均匀强化。MR检查,4例T1WI肿瘤表现为高信号,1例T1wI肿瘤表现为不均匀低信号;5例增强扫描肿瘤明显增强。结论：MRI有助于颅内黑色素瘤的诊断,在一定程度上可以区分原发性和转移性黑色素瘤。     

胎盘植入的影像学表现(病例报道及文献复习)

目的:探讨胎盘植入(placental implantation abnormality,PIA)的影像学表现特征。方法:分析经手术病理证实的1例胎盘植入的MRI及超声表现,并复习文献资料。结果:MRI:以同序列子宫外围肌层信号为参照,T_1WI植入胎盘呈等信号或略高信号,与宫壁结构分界不清;T_2WI植入胎盘呈高信号,信号强度高于宫壁,胎盘组织侵入肌层,结合带局部变薄或中断;T_1WI增强,胎盘显著强化,明显强于宫壁。超声:局部胎盘厚度增加,其内见多个大小不一、形态不规则的无回声区;胎盘后方子宫肌层厚薄不均,其内见大片状稍强回声区;胎盘与子宫肌层接触的地方有异常的彩色的血流。结论:胎盘植入的影像学表现具有特征性,MRI结合超声检查有助于做出正确的定位和定性诊断。     

Fluid collection within the synovial sheath of the tendon of the flexor hallus longus muscle in the tarsal joint of rats: an anatomic variant detectable with magnetic resonance imaging

Magnetic resonance (MR) images of the right tarsal joint of 22 normal male Han:Wistar rats were acquired using a 4.7 T magnet. An intermediate-high signal area associated with the tendon of the flexor hallus longus muscle was noticed in three rats on T2-weighted images. These areas appeared as an intermediate-high signal on lightly T2-weighted images, but appeared as an iso-signal to muscle structure on proton density weighted images. Histology preparations showed that such areas were caused by a sizable fluid collection within the synovial sheath of the tendon of the flexor hallus longus muscle, with all other joint structures appearing normal. This anatomic variant could be potentially regarded as a lesion on T2-weighted MR images, such as inflamed tissue with oedema, especially when the spatial resolution and/or signal-to-noise ratio are not optimal.     

肝癌自发性破裂出血的MRI诊断

目的：探讨肝癌自发性破裂出血的MRI图像特征。方法：对6例经手术或肝动脉血管造影确诊为原发性肝癌破裂出血患者的MR图像进行回顾性分析,总结其临床特点及MRI图像特征。结果：6例患者均行MR平扫及增强扫描,肝被膜下出血4例,腹腔内出血2例。出血表现为T1WI呈高或等信号,T2WI呈高或低信号,5例可清晰显示肿瘤破口。结论：MR诊断肝癌自发性破裂出血及时、准确,T1WI及延迟扫描冠状位图像对诊断有定性意义。     

Magnetic Resonance Imaging Assessment of Effective Ablated Volume following High Intensity Focused Ultrasound

Under magnetic resonance (MR) guidance, high intensity focused ultrasound (HIFU) is capable of precise and accurate delivery of thermal dose to tissues. Given the excellent soft tissue imaging capabilities of MRI, but the lack of data on the correlation of MRI findings to histology following HIFU, we sought to examine tumor response to HIFU ablation to determine whether there was a correlation between histological findings and common MR imaging protocols in the assessment of the extent of thermal damage. Female FVB mice (n = 34), bearing bilateral neu deletion tumors, were unilaterally insonated under MR guidance, with the contralateral tumor as a control. Between one and five spots (focal size 0.5 × 0.5 × 2.5 mm³) were insonated per tumor with each spot receiving approximately 74.2 J of acoustic energy over a period of 7 seconds. Animals were then imaged on a 7T MR scanner with several protocols. T1 weighted images (with and without gadolinium contrast) were collected in addition to a series of T2 weighted and diffusion weighted images (for later reconstruction into T2 and apparent diffusion coefficient maps), immediately following ablation and at 6, 24, and 48 hours post treatment. Animals were sacrificed at each time point and both insonated/treated and contralateral tumors removed and stained for NADH-diaphorase, caspase 3, or with hematoxylin and eosin (H&E). We found the area of non-enhancement on contrast enhanced T1 weighted imaging immediately post ablation correlated with the region of tissue receiving a thermal dose CEM43 ≥ 240 min. Moreover, while both tumor T2 and apparent diffusion coefficient values changed from pre-ablation values, contrast enhanced T1 weighted images appeared to be more senstive to changes in tissue viability following HIFU ablation.     

肝癌自发性破裂出血的MRI诊断

目的:探讨肝癌自发性破裂出血的MRI图像特征。方法:对6例经手术或肝动脉血管造影确诊为原发性肝癌破裂出血患者的MR图像进行回顾性分析,总结其临床特点及MRI图像特征。结果:6例患者均行MR平扫及增强扫描,肝被膜下出血4例,腹腔内出血2例。出血表现为T1WI呈高或等信号,T2WI呈高或低信号,5例可清晰显示肿瘤破口。结论:MR诊断肝癌自发性破裂出血及时、准确,T1WI及延迟扫描冠状位图像对诊断有定性意义。     

血源性兔VX2肿瘤脑及脑膜转移瘤动物模型的建立及MRI检测

目的：研究MRI对血源性脑及脑膜转移瘤动物模型转移灶的检出效果。方法：18只新西兰大白兔随机分为3组,分别从左颈总动脉内接种VX2瘤细胞,A组：20％甘露醇注入5min后接种VX2瘤细胞：B组：20％甘露醇注入5min后,加入肝素再接种VX2瘤细胞;C组,对照组,单纯注入等量生理盐水。术后2周后行MRI检查。病理取材HE染色光镜下观察。结果：平扫：A组,1只（1／6）发现脑内结节并脑膜结节样增厚,T1WI为等信号,T2WI为稍高信号。B组,2只（2／6）为脑内多发结节,T1WI为等信号,TM为稍高信号。2只（2／6）脑膜结节样增厚。增强扫描：A组,2只（2／6）脑内见强化结节灶;直径在1．5mm-7．0mm之间。4K（4／6）脑膜线样增厚或结节样增厚强化。B组,6只（6／6）脑内见直径在1．5mm-5．0mm的高信号结节,其中5只为脑内多发结节灶;4只（4／6）脑膜线样或结节样增厚强化,左侧为主,其中2只（2／6）为双侧脑膜增厚。增强扫描A、B组问脑内病灶差异有统计学意义（Fisher’s确切概率值为0．04）。C组平扫及增强扫描均未见异常信号。结论：上述方法制成的动物模型可为医学影像学研究提供可靠的动物模型,加入肝素可提高瘤灶的形成几率,并证实血脑屏障对脑转移瘤的形成起重要作用。MRI增强检查是检出脑内及脑膜转移瘤的首选方法。     

The Utility of Gadoxetic Acid-Enhanced MR Imaging to Characterize Atypical Cirrhotic Nodules Detected on Dynamic CT Images

Purpose

To evaluate whether gadoxetic acid (Gd-EOB-DTPA)-enhanced MR images of tumors taken during the hepatocyte-specific phase can aid in the differentiation between hepatocellular carcinoma (HCC) and dysplastic nodules (DNs) in patients with atypical cirrhotic nodules detected on dynamic CT images.

Materials and Methods

Seventy-one patients with 112 nodules showing atypical dynamic enhancement on CT images underwent gadoxetic acid-enhanced MR imaging (MRI) studies. Using a reference standard, we determined that 33 of the nodules were DNs and that 79 were true HCCs. Tumor size, signal intensity on precontrast T1-weighted images (T1WI) and T2WI, and the pattern of dynamic enhancement on MR images taken in the hepatocyte-phase were determined.

Results

There were significant differences in tumor size, hyperintensity on T2WI, hypointensity on T1WI, typical HCC enhancement pattern on dynamic MR images, or hypointensity on hepatocyte-phase images between DNs and HCC. The sensitivity and specificity were 60.8% and 87.9% for T2WI, 38.0% and 87.9% for T1WI, 17.7% and 100% for dynamic MR imaging, 83.5% and 84.9% for hepatocyte-phase imaging, and 60.8% and 87.9% for tumor size (threshold of 1.7 cm).

Conclusion

Gd-EOB-DTPA-enhanced hepatocyte-phase imaging is recommended for patients at high risk of HCC who present with atypical lesions on dynamic CT images.     

Hepatocellular Carcinoma in Budd-Chiari Syndrome: Enhancement Patterns at Dynamic Gadolinium-Enhanced T1-Weighted MR Imaging

The objective of this study was to analyze the enhancement patterns at dynamic gadolinium-enhanced T1-weighted MR imaging in patients of Hepatocellular Carcinoma (HCC) with associated Budd-Chiari syndrome (BCS). The MR imaging findings in 10 patients of HCC with associated BCS were compared to those of 32 other patients of HCC without BCS. During the arterial phase, significantly more lesions with BCS were hyperintense than lesions without BCS; during the equilibrium phase, significantly more lesions with BCS were slightly hyperintense or isointense than lesions without BCS (P < 0.05 for both). For HCC, contrast enhancement on MRI shows different enhancement patterns between patients of HCC with associated BCS and those without BCS.     

FLAIR和DWI在急性脑梗塞中的应用

目的比较液体衰减反转恢复(FLAIR)和弥散加权成像(DWI)在急性脑梗塞中的应用。方法14例急性脑梗塞患者接受FLAIR和DWIMRI检查评价病变的显示范围,边界及对比度并计算病变区。结果FLAIR序列和DWI对病变的显示范围,均优于常规T2WI,以DWI对病变显示更佳。结论FLAIR和DWI在急性脑梗塞中均有用,以DWI最好,且能对急性脑梗塞作定量评价。     

Using magnetic resonance imaging to identify the lumbosacral segment in children

Identification of the lumbosacral (L-S) segment on magnetic resonance (MR) images is important for appropriate treatment of disease in the lumbosacral (L-S) area. In the study, data obtained from plain A-P radiographs of the L-S spine and sagittal MR imaging scans (sagittal T1- and T2-weighted sequences) of the L-S spine and sacrum with the coccygeal bone, are analyzed. Twenty-six children aged 10 to 14 years were examined for back pain. On the standard A-P radiographs of the L-S spine, a L-S transitional vertebra as classified according to the method of Castellvi et al. was found in 17 subjects. The problem arose as to whether this was lumbalisation or sacralisation, and how to determine which vertebra was L5 wich S1. On the sagittal MR imaging studies the same question applied. A need emerged for a simple method which would identify the L-S segment on the sagittal MR imaging studies of the L-S spine in children so that in case of a tumor, inflammation, spondilolystesis, or protrusion of a disc, the level in the L-S spine where the problem is localized can be accurately identified. To this objective we selected the method using detection of the S1 vertebra. This involved that, in addition to the sagittal MR imaging scans of the L-S spine, sagittal images of the sacrum and coccygeal bone be also obtained. on the T2-weighted sequence, the sacrum can be clearly distinquished from the coccygeal bone. By counting from the S5 up, the S1 vertebra can be accurately identified. Determination of the S1 vertebra enables detection of the L5 vertebra and, in turn, of all other lumbar vertebrae. In patients in whom a T2-weighted MR studies were done S1 could be precisely determined and so could the L5 vertebra. In this process, whether the patient had a transitional vertebra or whether there was lumbarisation or sacralisation was irrelevant.