原发性脑淋巴瘤的MRI表现特点与诊断

目的：分析颅内原发性淋巴瘤的MRI表现特点，为临床诊断与治疗提供资料。方法：回顾分析28例经病理证实颅内原发性淋巴瘤的MRI资料，所有病例均行平扫及增强扫描。结果：病灶单发6例，多发22例，分布于幕上14例，幕下4例，幕上幕下同时存在10例，大多位于深部脑白质，病灶多呈圆形或不规则形，T1WI呈低信号，T2WI呈等或高信号，瘤周水肿较轻，增强扫描病灶均呈团块状显著强化。结论：颅内淋巴瘤的MRI表现缺乏特异性，需手术或活检才可作出定性诊断。     

原发性中枢神经系统弥漫大B细胞性淋巴瘤16例临床病理分析

目的 探讨原发性中枢神经系统弥漫大B细胞淋巴瘤(diffuse large B-cell lymphomas,DLBCL)的临床病理特点和免疫分子亚型及与预后的相关性.方法 回顾性分析16例原发性中枢神经系统DLBCL的临床表现、影像特点,采用HE染色及EliVision法观察其病理组织学特点和免疫表型特征.结果 临床上主要表现为颅内压增高、肢体乏力、视力障碍和神经精神症状,可为单发或多发性病灶;影像学上,CT示肿块多呈稍低密度阴影,MRI示T1WI呈低或等信号,T2WI呈高或等信号,强化明显,病灶周围常见明显水肿带.组织学特点为瘤细胞细胞形态较单一,弥漫浸润,瘤细胞常围绕血管形成袖套状,伴片状坏死及出血.免疫分子分型示9例DLBCL为生发中心型,7例为非生发中心型.结论 原发性中枢神经系统DLBCL是高度侵袭性淋巴瘤,为2008年WHO淋巴造血系统肿瘤分类已新增加的DLBCL亚型,具有较独特的临床病理学特点及生物学行为.好发中老年人,临床表现和影像学缺乏特异性.病理组织形态特点为瘤细胞弥漫或结节分布,以瘤细胞常围绕血管袖套状浸润为其特征性结构,可有坏死、出血;分子亚型主要为生发中心型.     

免疫状态正常人原发性脑淋巴瘤的CT及MRI诊断

目的探讨免疫状态正常人原发性脑淋巴瘤的CT及MRI影像特点。方法回顾性分析16例经病理证实原发性脑淋巴瘤的CT和MRI影像表现。结果老年男性多见,病灶多发多见,近中线室管膜周围脑白质及脑表面多见。CT平扫病灶呈等或稍高密度,MR平扫T1WI呈等或稍低信号,T2WI呈等或稍高信号,病灶信号多较均匀,少见囊变、坏死,周围水肿及占位效应多较轻,T2-FLAIR及DWI多呈均匀性稍高或高信号,病灶多均匀性强化,可呈"握拳状"、裂隙状分叶改变。结论免疫状态正常人原发性脑淋巴瘤的CT及MRI影像表现具有一定特征性,影像诊断具有重要临床意义。     

原发性中枢神经系统淋巴瘤107例临床病理观察

目的：对原发性中枢神经系统淋巴瘤（PCNSLs）进行临床与病理观察，进一步认识其病理特性。方法：分析107例PCNSLs的临床资料，行HE染色与免疫组化（ABC法）LCA、L26、UCHL－1、Lyso、α1－AT、MAC、GFAP、S－100蛋白、EMA等标记，并区分T、B细胞类型。结果：该肿瘤以40岁以上中老年人多见，以颅内压力增高或肢体麻瘫为主要表现，肿瘤可发生于中枢神经系统的任何部位，以侵犯大脑半球（尤以额、颞叶）较多，PCNSLs的组织学特征为淋巴瘤的瘤细胞形态较单一，如体躯性淋巴瘤胞质常少；病灶周边区瘤细胞常围绕血管形成袖套状，病灶中央的瘤细胞呈片状分布伴灶性坏死和出血，肿瘤侵及脑膜可引起胶原纤维增多，免疫组化染色的33例中，有29例（占84.8%）为B细胞型，其中1例为富T的B细胞型；4例（15.2%）为T细胞型。结论：PCNSLs为高度恶性肿瘤，临床上起病急，主要表现为颅内压力增高、肢体乏力、瘫痪和神经精神症状；瘤细胞形态相似于体躯性淋巴瘤肿瘤周边部瘤细胞，有向血管性，以血管为中心，侵犯血管壁开成袖套状，中心部瘤细胞呈温分布，有坏死、出血，免疫组化显示为B细胞型与T细胞型，患者预后差。     

原发性中枢神经系统淋巴瘤临床病理观察

原发性中枢神经系统淋巴瘤(primary central nervous system lymphoma,PCNSL)是一种仅局限于中枢神经系统的结外淋巴瘤,是一种少见的中枢神经系统恶性肿瘤,约占颅内原发性肿瘤的0.3%～1.5%,占全身淋巴瘤1%以下,不向中枢神经系统以外播散[1].为了提高对本病的认识,本文收集了8例PCNSL,结合文献报道对其临床病理特征、免疫组化表型、预后及鉴别诊断进行探讨.     

MRI在腮腺上皮性良性肿瘤定性诊断价值及其病理基础

目的探讨MRI在腮腺上皮性良性肿瘤定性诊断中的作用.方法收集腮腺上皮性良性肿瘤72例80个病灶的MRI资料,其中70例经手术病理证实,2例活检证实.77个手术切除病灶行病理逐层切片检查并与MRI影像进行对照分析.MRI平扫采用T1WI、T2WI,其中61例共67个病灶同时行平扫和增强扫描.结果超过一半的腺淋巴瘤瘤灶(26个)T2WI表现为低、等信号,所有经过增强的42个腺淋巴瘤均轻度增强;31例混合瘤T2WI表现为高而不均匀信号,经过增强的24例混合瘤均中等或显著强化.结论常见腮腺上皮性良性肿瘤在MRI表现上各有特点,对大多数病例进行定性诊断是可能的.     

MRI在腮腺上皮性良性肿瘤定性诊断价值及其病理基础

目的　探讨MRI在腮腺上皮性良性肿瘤定性诊断中的作用 .方法　收集腮腺上皮性良性肿瘤 72例 80个病灶的MRI资料 ,其中 70例经手术病理证实 ,2例活检证实 .77个手术切除病灶行病理逐层切片检查并与MRI影像进行对照分析 .MRI平扫采用T1WI、T2WI,其中 6 1例共 6 7个病灶同时行平扫和增强扫描 .结果　超过一半的腺淋巴瘤瘤灶 (2 6个 )T2WI表现为低、等信号 ,所有经过增强的 4 2个腺淋巴瘤均轻度增强 ;31例混合瘤T2WI表现为高而不均匀信号 ,经过增强的 2 4例混合瘤均中等或显著强化 .结论　常见腮腺上皮性良性肿瘤在MRI表现上各有特点 ,对大多数病例进行定性诊断是可能的     

原发性中枢神经系统淋巴瘤9例浸润播散方式的临床病理观察

目的 探讨原发性中枢神经系统淋巴瘤(primary central nervous system lymphoma,PCNSL)在脑组织内浸润播散的方式.方法 复习9例PCNSL的临床病理资料,重点观察其在脑组织内浸润播散方式.结果 9例PCNSL中,8例为手术标本,1例为尸解标本,病理类型均为非霍奇金淋巴瘤,8例为弥漫大B细胞淋巴瘤,1例为非特异性外周T细胞淋巴瘤,中位年龄57岁,观察到3种基本浸润和播散方式:(1)沿血管周隙浸润,破坏血管周隙在血管周围浸润,侵入血管壁呈血管炎状改变,使血管腔闭塞.(2)沿神经束间浸润,在大脑灰质层和小脑分子层形成单个或数个细胞与脑表面垂直的条索向脑表面软脑膜下浸润.(3)上述两种方式浸润的瘤细胞最终进入脑皮质浅层和蛛网膜下腔.结论 PCNSL沿血管周隙、血管周围、神经纤维间隙等结构浸润至脑皮层浅层和蛛网膜下隙,并进一步播散.     

原发性中枢神经系统淋巴瘤VEGF、MVD与影像学对比研究

目的 :分析原发性中枢神经系统淋巴瘤 (PCNSL)的VEGF表达分布和测量其微血管密度 (MVD) ,旨在提高PCNSL早期诊断率和判断预后 ,同时为影像学提供理论依据。方法 :对 2 2例PCNSL临床 (包括影像学 )病理资料分析 ,同时行VEGF及CD34免疫组化标记 ,并测量MVD ,以 12例胶质瘤作为对照。结果 :2 2例PCNSL中单发者 17例 (占 77 2 7% ) ;多发者 4例 ,共有病灶 10处 ;1例为弥漫浸润型。肿瘤位于脑白质深部者 15例 (占 5 5 5 6 % )、脑表面及灰白质交界区者 8例、胼胝体者4例。CT示肿瘤为边界清楚的高密度结节或肿块。组织病理学示瘤细胞弥漫分布 ,瘤细胞大小较一致 ,胞质少 ,核大 ,可见瘤细胞围绕血管呈“袖套样”浸润。淋巴瘤MVD值 (2 1 8± 11 6 )与恶性胶质瘤组 (44 4± 16 8)的差异有非常显著性 (t =3 374 ,P <0 0 1)。VEGF表达无特异性 ,与对照组比较无统计学意义。结论 :病理学基础决定了影像学的特征。血管生成活性的不同 ,有助于PCNSL与恶性胶质瘤的鉴别 ,并对其预后的判断有一定帮助 ,VEGF可能是恶性肿瘤重要的促血管生成因子 ,但对于鉴别诊断无特异性。     

中枢神经系统原发性恶性淋巴瘤临床与病理分析

通过对１４例中枢神经系统原发性恶性淋巴瘤临床资料分析及光镜，电镜和免疫组化研究，结果表明：临床上以颅内压增高为主要症状，肿瘤可发生于中枢系统的任何部位。组织学特点，瘤细胞单一，异形，早期常围血管呈袖套样排列，中晚期呈弥漫性分布，无滤波形成。ＬＣＡ，Ｌ２６，ＵＣＨＬ１，ＧＦＡＰ，ＥＭＡ免疫组织化学染色及电镜检查提示肿瘤多数为Ｂ细胞起源。并对其病间，发病机理，诊断和鉴别诊断作了讨论     

应用MRI技术对肝脏局灶结节性增生的诊断

目的 评估磁共振成像（magnetic resonance imaging,MRI）技术对肝脏局灶结节性增生（focal nodular hyperplasia,FNH）的诊断价值.方法 回顾性分析齐齐哈尔市第一医院2008年1月至2010年4月经手术切除或穿刺活检病理证实的10例26灶FNH 磁共振平扫、动态增强表现,由3名有经验的医师做MR表现诊断.结果 对于10例中的26个病灶,平扫T1WI上23个病灶为稍低或等信号、3个病灶为稍高信号;T2WI上23个病灶呈稍高信号、1个病灶等信号,2个病灶呈稍低信号.在动脉期5个病灶明显不均匀增强、19个病灶显著均匀增强,门静脉期和延迟期13个病灶呈稍高信号,11个病灶呈等/稍低信号,2个病灶无强化.11个病灶检出瘢痕,T1WI呈低信号,T2WI呈低或高信号,动脉期无增强、门静脉期或延迟期增强.8例诊断正确,1例诊断为良性病变（定性困难）,1例误诊为恶性肿瘤.结论 MRI能显示单发或多发FNH的特征性改变,并在术前正确诊断大部分FNH.     

Serial proton spectroscopy,magnetization transfer ratio and T 2 relaxation in pseudotumoral demyelinating lesions

In some rare cases, demyelinating plaques appear on contrast-enhanced T1-weighted images as pseudotumoral, cyst-like lesions (hypointense, ring enhancing). Serial proton MR spectroscopy, T2 relaxometry and magnetization transfer ratios (MTR) were performed on three pseudotumoral demyelinating lesions to obtain information about their pathological basis. Baseline and 1-month MTR and T2 values were similar to those of cerebrospinal fluid, while spectra showed lactate, lipids and choline. Three-month and 1 year exams showed recovery of MTR, T2 and N-acetylaspartate, approaching the contralateral values, while creatine and choline were normal or surpassed contralateral values. Lipids and lactate gradually disappeared. These results suggest that pseudotumoral, cyst-like, ring-enhancing lesions may be characterized by an accumulation of oedema in the extracellular space with an almost complete absence of cells. Reduction of the oedema allows restoration of the tissue to its original location, indicating that cellular destruction was less important than was expected after the first exam. Thus, the evolution of this kind of lesion should be kept in mind when considering lesion volume from T1-weighted images as a marker of disability or irreversible cellular destruction in MS.     

原发性中枢神经系统淋巴瘤2例临床病理分析并文献复习

目的探讨原发性中枢神经系统淋巴瘤(primary central nervous system lymphoma,PCNSL)的临床特点、病理诊断、治疗及预后。方法对2例PCNSL进行免疫组化染色并复习相关国内外文献。结果 2例PCNSL,1例为间变性大细胞型-T细胞来源,另1例为弥漫性大B细胞型,HIV均阴性。PCNSL临床表现无特异性,颅内压增高、精神失常为常见症状,影像检查缺乏特征性改变,免疫表型以B细胞为主(87.5%～98%),大剂量氨甲蝶呤联合全脑放疗缓解率高。结论 PCNSL术前难以诊断,需依赖病理检查确诊,治疗困难,预后差。     

3.0T超导型MRI灌注加权成像联合动态增强扫描技术在乳腺早期良恶性病变鉴定中的研究

目的探讨3.0 T超导型MRI灌注加权成像(PWI)联合动态增强扫描(DCE)在乳腺早期良恶性病变鉴定中的价值。方法选择术后经病理确诊为良恶性的乳腺早期病变女性患者61例,年龄24~65岁,平均年龄30.12岁。所有患者均经3.0 T超导型MRI PWI常规T2加权成像(T2WI)和T1加权成像(T1WI)平扫后行三维(3D)动态增强扫描技术,并根据病理结果分为恶性病变和良性病变,对比病变形态学变化、时间-信号强度曲线(TIC)及表观弥散系数(ADC)值,并分析PWI联合DCE对乳腺早期良恶性病变鉴别诊断价值。结果病理结果为恶性病变27例,良性病变34例;DCE-MRI扫描结果为恶性病变患者20例,良性病变患者26例,病变检出率75.41%;PWI扫描结果为恶性病变患者21例,良性病变患者27例,病变检出率78.69%。乳腺早期良性病变形态以类圆形(76.5%)、边缘以光滑(70.6%)为主,乳腺早期恶性病变形态以分叶形(63.0%)、边缘以毛刺征(59.3%)为主;乳腺早期良恶性病变DCE-MRI扫描形态学特征对比,差异有显著统计学意义(χ^2=43.557、37.459,P=0.000、0.000)。乳腺早期良性病变TIC形态以Ⅰ型(61.8%)为主,乳腺早期恶性病变TIC形态以Ⅲ型(77.8%)为主,两者比较,差异有显著统计学意义(χ^2=121.852,P=0.000);22例(81.5%)恶性病变患者ADC值≤1.195×10-3 mm2/s,28例(82.4%)良性病变患者ADC值>1.195×10-3 mm2/s,两者差异有显著统计学意义(χ2=26.148,P=0.000)。二者联合鉴别诊断乳腺早期良恶性病变的灵敏度、特异度及准确度与DCE-MRI、PWI单一诊断更高(P<0.05)。结论 3.0 T超导型MRI PWI联合DCE在乳腺早期良恶性病变鉴定中具有较高的临床价值。     

Sequential changes of traumatic vertebral compression fracture on MR imaging.

The purpose of this study was to evaluate the sequential signal intensity changes in post-traumatic vertebral compression fractures of varying ages. Sixty-six patients with 115 post-traumatic vertebral compression fractures underwent MR imaging. The ages of fractures at the time of MR images ranged from 1 day to 6 years. Sequential follow-up MR imagings were obtained in 4 patients for 2 years after initial MR examination. The fracture sites in all 52 fractures with traumatic events less than 3 months prior were hypointense on T1-weighted images and hyperintense on T2-weighted images (type I). A type I fracture could be subdivided into 3 patterns depending on its morphologic appearance: diffuse (type Ia); patchy (type Ib); and bandlike (type Ic). In 12 fractures of 3 to 5 months after trauma, six showed focal hypointensity (type II) in all pulse sequences, and six showed isointensity (type IV). Four of 51 fractures with trauma over 5 months showed focal hyperintensity on T1-weighted images and isointensity on T2-weighted images (type III); and the remaining 47 fractures showed isointensity on all sequences (type IV). In conclusion, MR imaging is useful in predicting the age of known traumatic compression fractures, so familiarity with these sequential MR findings would be helpful in distinguishing benign from malignant fractures.     

CT and MR findings of primary cardiac lymphoma: report upon 2 cases and review

Although primary cardiac lymphoma was a near fatal disease in the past, recent advances in imaging diagnosis and chemotherapy have dramatically improved survival. We describe the CT and MR findings of primary cardiac lymphoma in two immunocompetent subjects who recovered after chemotherapy. The primary cardiac lymphomas manifested as a poorly enhancing mass on CT, relatively hyperintense on a T2-weighted image and a heterogeneously enhanced mass on contrast-enhanced MR. The tumor also showed a predilection for right heart chambers and contiguous infiltration along adjacent structures.     

Magnetic resonance imaging characteristics of deep endometriosis

The aim of this study was to describe magnetic resonance (MR) imaging findings in histopathologically proven deep endometriosis infiltrating the uterosacral ligaments, the pouch of Douglas, the rectum or the bladder. Twenty patients presenting with a clinical suspicion of deep endometriosis underwent preoperative MR imaging. Sagittal and axial fast T2- and axial T1-weighted spin echo MR sequences were performed. Four patients had post-contrast images. MR results, including morphology and signal intensity of each lesion, were compared to intraoperative gross appearance and histopathology. Histopathology diagnosed 24 lesions of deep endometriosis in the uterosacral ligaments (n = 12), the pouch of Douglas (n = 2), the rectum (n = 3), the bladder (n = 7). Uterosacral ligaments with deep endometriosis were statistically different from normal uterosacral ligaments for proximal nodularity (P = 0.001). There was no difference in signal intensity between normal and abnormal uterosacral ligaments. Contrast-enhanced SE images in four patients with detrusor invasion showed an interruption of the hypointense detrusor by the enhancing bladder endometriosis. Rectal endometriosis was missed in two of three patients and showed non-specific rectal wall thickening in one patient. It is concluded that MR imaging can diagnose deep endometriosis of uterosacral ligaments, the bladder and the pouch of Douglas, but lacks sensitivity in detecting rectal endometriosis without rectal distension.     

Distinguishing of primary cerebral lymphoma from high-grade glioma with perfusion-weighted magnetic resonance imaging

To assess the usefulness of perfusion-weighted echo-planar magnetic resonance imaging in the differential diagnosis of primary supratentorial lymphoma (PCNSL) and glioblastoma (GBM), 12 patients with a PCNSL and 12 with a GBM were examined using a 1.5 T magnetic resonance (MR) imager. With dynamic-susceptibility contrast MR imaging the intensity-time curves of each tumor were analyzed, and we determined the relative regional cerebral blood volume ratios (rrCBV [tumor/contralateral white matter (WM)]) to find out whether these parameters could be used to separate PCNSL from GBM. The maximum rrCBV ratio in the PCNSL was significantly lower than that of the GBM (P<0.0001). Comparing the intensity-time curves for the two tumor groups, the PCNSL showed a characteristic type of curve with a significant increase in signal intensity above the baseline due to massive leakage of contrast media into the interstitial space. PCNSL tend to have low maximum CBV ratios and typical intensity-time curves. These two parameters may be useful in distinguishing PCNSL from GBM.     

Specific identification of iron oxide-labeled stem cells using magnetic field hyperthermia and MR thermometry

Cell-based therapies represent important novel strategies for the improved treatment of various diseases. To monitor the progress of therapy and cell migration, noninvasive imaging methods are needed. MRI represents such a modality, allowing, for example, for the tracking of cells labeled with superparamagnetic iron oxide nanoparticles. Unfortunately, the labeled cells cannot always be identified nonambiguously in the MR images. In this article, we present the combination of two different types of MR experiment to identify iron oxide-labeled cells nonambiguously. The labeled cells appear as hypointense spots on standard T(2)*-weighted MR images. Furthermore, they can be heated magnetically and subsequently identified by MR thermometry as a result of their heat dissipation. Other hypointense regions in the MR images are not heated and do not show heat dissipation. A proof-of-principle study was successfully performed in vitro and in vivo. The positive identification of the iron oxide-labeled cells was demonstrated in collagen type I hydrogel phantoms and in living mice with high spatial and temporal accuracy. The motion of the in vitro samples was corrected in order to improve the specificity of the identification of labeled cells. Therefore, this method possesses the potential for cell tracking without prior knowledge about the cells, and thus allows the noninvasive monitoring of cell-based therapies, as long as the cells contain a sufficient amount of iron oxide for detection in MR thermometry and imaging.     

Ultra-high b-value diffusion-weighted imaging features of the prostatic leiomyoma-case report

Background

Leiomyoma of the prostate is a rare benign tumor arising from smooth muscle fibers. Most cases are incidental findings observed during pathological examinations after resection of the prostate. To the best of our knowledge, only few studies have reported the conventional magnetic resonance imaging (MRI) findings of such tumors; however, no reports have described the ultra-high b-value diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) findings of prostatic leiomyomas.

Case presentation

We report MR imaging characteristics and surgical pathologic findings of a case of prostatic leiomyoma treated by robot-assisted transperitoneal laparoscopic approach. Typical MR features showed a homogeneous lesion with slightly hypointense signal compared to the skeletal muscle on T2-weighted images, and isointense signal relative to the muscle on T1-weighted images with fat suppression, which collectively demonstrate apparent homogeneous enhancement with a non-enhanced envelope. A slightly hyperintense signal compared to the skeletal muscle was observed on ultra-high b-value DWI, and higher ADC values were observed as compared to the prostate cancer.

Conclusions

Prostatic leiomyoma is a benign tumor. This case indicates that MRI features of prostatic leiomyoma are helpful for the differential diagnosis of prostate cancer.