低场MR动态增强对肝脏占位病变的诊断价值探讨

目的：探讨低场MR动态增强对肝脏占位病变的应用价值。方法：应用0．2T永磁型磁共振仪对24例肝脏占位性病变先行TIW1、T2WI平扫，再使用FMPSPGR(快速多层面扰相位梯度回波)序列，进一步对其中28个占位灶作同层块动态增强扫描。造影剂为磁显葡胺(Gd-DTPA)0．2mmol／kg。结果：在上下5～8cm范围内可显示肝脏占位病变的动态强化方式，有助于定性诊断。结论：低场MR动态增强可作为肝脏占位病变定性诊断的补充方法。     

MR波谱及立体定向活检诊断颅内炎性病变1例

1病例报告患者男,28岁。无任何不适症状。体检时行头部CT检查,疑为颅内占位病变。入院后影像学检查：头部MR平扫及增强片显示：右侧额叶占位病变,增强后未见明显强化（图1）。     

颅内巨大的表皮样囊肿的MRI诊断和鉴别诊断

目的:探讨颅内巨大表皮样囊肿的MR影像表现,分析磁共振在颅内巨大表皮样囊肿诊断和鉴别诊断价值。材料与方法:分析15例手术病理证实为颅内巨大表皮样囊肿的MR影像表现及术前做T1W、T2WI的MR常规平扫、T2-FLAIR、DWI和增强MRI影像表现。结果:14例T1WI呈低信号,只有1例T1WI呈高信号,T1-STIR未能抑制。所有病例T2WI呈高信号,稍高于脑脊液。所有病例T2-FLAIR囊内见不同数量的絮状稍高信号影。DWI均表现为明显高信号,信号不均匀。增强多无强化或囊壁轻度强化,其中3例发生恶性变者局部囊壁呈结节状明显强化。结论:颅内巨大表皮样囊肿MR表现具有明显的特征性,对本病的诊断与鉴别诊断具有价值。T2-FLAIR信号对于诊断最具有特征性,颅内巨大表皮样囊肿病灶检出方面,DWI均优于MRI平扫以及T2-FLAIR。增强扫描有利于病变良恶性鉴别。     

钆喷酸葡胺过敏二例报告

随着高场强磁共振的出现,磁共振检查在临床上应用更为广泛,磁共振增强扫描对诊断的价值也进一步为大家所公认。传统认为磁共振增强所用的造影剂使用起来相当安全,一般无过敏反应(?)现笔者在临床工作中遇到(?)例在使用钆喷酸葡胺(Gd-DTPA)造影剂后,出现过敏反应。现报道如下,旨在引起我们在MR检查工作中,对造影过敏反应的重视。 例1,男州,42岁。因主诉头痛、头晕、呕吐等症状,在外院行CT平扫疑颅内占位性病变,因有碘造影过敏史未能作增强扫描明确诊断,建议到我院作磁共振扫描检查,以确诊并作术前定位。 MR扫描前准备:打开静脉通道(留针固定)作自动注射     

第五届全国磁共振新技术应用与管理研讨会通知

磁共振对比剂可以提高磁共振成像分辨率,增加正常与病变组织的成像对比度,从而提高磁共振诊断疾病的敏感性和特异性。自从l984年Weinmann和Brasch等首次应用二乙三胺五乙酸钆（Gd—DTPA）作为磁共振造影剂应用于脑部肿瘤增强MR信号以来,磁共振对比剂增强扫描解决了许多临床诊断难题。     

三维Sono CT在膀胱恶性占位病变诊断中的临床应用

目的：探讨三维Sono CT对膀胱恶性占位病变的诊断价值。方法：对9例膀胱恶性占位病变患者共14枚性肿瘤分别采用二维SonoCT 显像及三维SonoCT成像检查并对二种图像效果进行对比研究。结果：二维SonoCT显像较常规二维超声能够较好显示膀胱癌的部位,,数目以及肿瘤的边界,内部回声以及对膀胱壁的润情况,三维SonoCT对膀胱恶性占位病变的诊断价值明显高于二维SonoCT显像,三维SonoCT所建的傍胱恶性占位病变图像极其逼真清晰,立体感极强,空间关系明确,形态非常直观,三维SonoCT操作简便,其三维图像采集与二维显像均是同一阵探头,不需用更换专用探头。三维SonoCT成像速度快,图像后处理非常快捷。结论：三维SonoCT可以更加清晰逼真地显示膀胱恶性占位病变的部位,大小,范围,形态,浸润膀胱壁情况,可以为临床医师诊治方案的制定提供更加丰富,更加令人信服的信息。     

国产MRI顺磁性造影剂Gd—DTPA初步应用

随着磁共振成像(MRI)诊断技术的日趋发展,顺磁性造影剂在临床的应用也逐渐广泛,并提高了MRI的诊断效果。由广州第一军医大学研制的造影剂维影钆胺(Gd—DTPA),是国内首家推出的MR顺磁性静脉内造影剂。现就我院首批使用该产品32例报告如下。     

两种不同弛豫率钆对比剂在脑转移瘤中的磁共振对比研究

目的 对比研究钆贝葡胺(Gd-BOPTA)与钆喷酸葡胺(Gd-DTPA)在磁共振增强榆查中对脑转移瘤的诊断价值.方法 第一部分同顾性分析40例无颅内疾患成人MR增强图像资料,其中20例应用钆贝葡胺,另20例应用钆喷酸葡胺,均使用标准剂量(0.1 mmol/kg体重),两组年龄、体重相匹配,比较两组下鼻甲与正常脑白质的对比噪声比.第二部分10例临床诊断为脑转移瘤患者间隔24～48小时分别用标准剂量(0.1 mmol/kg体重)钆贝葡胺与钆喷酸葡胺行磁共振增强检查,比较二者对转移瘤的显示情况及病灶与对侧正常脑白质的对比噪声比.结果 第一部分钆贝葡胺组下鼻甲与正常脑白质的对比噪声比(36/6±11.9)高于钆喷酸葡胺组(25.6士8.1),P=0.002.第二部分10例脑转移瘤中有3例钆贝葡胺增强检查比钆喷酸葡胺增强榆查多榆出一小病灶;5例钆贝葡胺比钆喷酸葡胺对病灶强化更明显;另2例两者无明显差别.钆贝葡胺与钆喷酸葡胺增强后病灶与对侧正常脑白质的平均对比噪声比前者(22.5±10.5)明显高于后者(12.0±6.4),P＜0.009.结论 同等剂量条件下,使用钆贝葡胺行MR增强检查不仅使脑转移瘤显示更清晰,对比更明显,而且能提高隐匿性病灶的检出率,改善临床治疗方案.     

原发性巨球蛋白血症颅内浸润一例报告附文献复习

目的 总结原发性巨球蛋白血症颅内浸润的诊疗体会.方法 对1例原发性巨球蛋白血症颅内浸润(Bing-Neel综合征)患者的临床资料进行分析,并进行相关文献复习,为其诊断和治疗提供思路.结果 患者1年前诊断为原发性巨球蛋白血症,治疗中患者出现持续性头痛.颅脑MRI平扫+增强:右侧额颞叶可见一团块状异常占位病变,T2呈高信号,增强后病灶强化明显;手术切除肿瘤组织行病理检查示额叶小细胞恶性肿瘤浸润;免疫组化染色检查示淋巴-浆细胞瘤样细胞颅内侵犯.结论 原发性巨球蛋白血症颅内浸润罕见,化疗疗效有限,理想的治疗应该是放疗联合化疗.     

原发性巨球蛋白血症颅内浸润一例报告附文献复习

目的 总结原发性巨球蛋白血症颅内浸润的诊疗体会.方法 对1例原发性巨球蛋白血症颅内浸润(Bing-Neel综合征)患者的临床资料进行分析,并进行相关文献复习,为其诊断和治疗提供思路.结果 患者1年前诊断为原发性巨球蛋白血症,治疗中患者出现持续性头痛.颅脑MRI平扫+增强:右侧额颞叶可见一团块状异常占位病变,T2呈高信号,增强后病灶强化明显;手术切除肿瘤组织行病理检查示额叶小细胞恶性肿瘤浸润;免疫组化染色检查示淋巴-浆细胞瘤样细胞颅内侵犯.结论 原发性巨球蛋白血症颅内浸润罕见,化疗疗效有限,理想的治疗应该是放疗联合化疗.     

Dynamic contrast-enhanced MR imaging of fibrolamellar hepatocellular carcinoma

The magnetic resonance (MR) appearance of fibrolamellar hepatocellular carcinoma (FL-HCC) on T1- and T2-weighted and dynamic serial postgadolinium-DTPA images is reported. Both tumors were large (>7 cm in shortest dimension) and had central regions of low signal intensity on T1- and T2-weighted images. Diffuse heterogeneous enhancement of the tumors occurred on immediate postcontrast images. Lesions became more homogeneous in enhancement over time, but lack of enhancement of central portions of the tumor persisted. Although persistent lack of enhancement of the tumor scar on late postcontrast MR images may be characteristic of FL-HCC compared with delayed enhancement in focal nodular hyperplasia, the potential similarities between these tumors is stressed.     

MR平扫和增强扫描在直肠癌分期的应用价值

目的 通过比较分析MR平扫与增强扫描在直肠癌分期及肿瘤外侵程度判断上的准确性，期望对单纯MR平扫与MR平扫加增强扫描在直肠癌的应用作出评价。方法 收集了1999年9月至2002年5月间临床诊断为直肠癌行MRI直肠检查，并有手术病理结果的病例共33例。采用MR平扫与薄层增强扫描等多个序列来观察直肠癌的外侵程度与范围。并应用直肠癌的TNM分期标准对MR成像与手术病理结果进行对照分析。结果 直肠癌的分期：在手术及病理诊断肿瘤限于黏膜下层以内的6例T1期肿瘤中MRI作出了准确诊断5例，1例高估为T2期，故其敏感性为100％、特异性为83．3％。其中在平扫T1、T2加权像时有2例认为T2期，但3D薄层增强成像1例作出了准确判断。1例仍判断错误(假阳性)。T3期的23例中，MRI平扫T1和T2加权像时诊断正确的21例。2例假阴性低估为T2期，其敏感性为91．3％，特异性为100％。而有薄层增强扫描的18例病人其诊断均与手术病理结果相符合。敏感性和特异性均为100％。T4期的病例共4例，MRI平扫与增强扫描均与手术及病理所见相符合，其敏感性与特异性均为100％。MRI总的分期准确率为90．9％。结论 MRI平扫加增强扫描对于直肠癌的术前分期及对肿瘤外侵深度的判断有较重要的临床应用价值。     

Eleven Patients With Testicular Leydig Cell Tumors

We present the sonographic and magnetic resonance imaging findings of Leydig cell tumors in a series of patients, along with a brief review of the literature. We evaluated the sonographic features of 11 cases of Leydig cell tumors, including echogenicity, size, margins, and patterns of vascularity. The magnetic resonance imaging characteristics of 9 patients were also assessed, with special attention to the appearance of the tumors on T2-weighted imaging and postcontrast T1-weighted imaging. Seven tumors were hypoechoic, and 4 were almost isoechoic. Ten patients showed various patterns of hypervascularity in the tumors, combined in some cases with feeding vessels. One case presented with a single feeding vessel. The tumors showed homogeneous or heterogeneous low signal intensity on T2-weighted imaging and marked enhancement on postcontrast T1-weighted imaging. The small size of these tumors, the various patterns of vascularity on color and power Doppler sonography, and the marked enhancement on postcontrast T1-weighted imaging are considered valuable but generally nonspecific for identification of these tumors.     

超顺磁性氧化铁(SPIO)增强MRI对原发性肝癌的诊断价值

目的：检验SPIO增强MRI对原发性肝癌的定位，定量，定性诊断价值。方法：选取经螺旋CT增强，MR平扫，SPIO增强扫描检查且有手术或穿刺活检病理或DSA血管造影资料并经随访，实验室生化检查及临床资料证实为原性肝癌者20例。结果：SPIO增强T2MRI检出79个病灶，其中经手术，穿刺活检病理证实或DSA血管造影显示有肿瘤血管团和/或肿瘤染色的原发性肝癌病灶69个；另有10个为异常信号灶，SPIO增强MRI较CT增强及MR平扫病灶检出率分别增加66%和59%，病灶-肝脏对比噪声比增加52%（P=0.004)。结论：（1）SPIO增强T2WI病灶-肝脏对比噪声比显著增加；（2）病灶检出率明显高于MR平扫及螺旋CT增强影像；（3）结合MR平扫影像，SPIO增强MR影像对肝癌病灶的定位。定量及定性诊断有重要意义；（4）SPIO增强MR影像对肝脏良恶性肿瘤的鉴别诊断有重要意义。     

肝脏肿瘤的MR检查与诊断思路

肝脏肿瘤病变组织学类型多种多样,MR影像学有较为独特的信号改变及强化特点。该文总结MRI检查技术要点,对常见肿瘤病变的信号特征、强化特征进行对比分析,旨在理清肝脏肿瘤病变的诊断思路,进一步提高影像诊断水平。     

Cystic islet cell tumors: Radiologic findings in three cases

We report three cases of cystic islet cell tumors, two caused by gastrinomas and the other by an islet cell carcinoma. All three patients underwent computed tomography (CT) and angiography and two also had magnetic resonance (MR) imaging. Several common radiographic findings were present as follows: thickening of the cyst wall and irregularity of the inner surface on postcontrast CT and MR images, neovascularity and a densely staining hypervascular rim on angiography, and moderately increased signal intensity of the cyst content on T1-weighted MR images, which indicated fluid containing blood and/or necrotic tissue. These findings are helpful in defining the nature of these lesions and strongly suggest that cystic islet cell tumor should be included in the differential diagnosis.     

脑肿瘤的~(201)Tl-SPECT和增强MRI的融合成像研究

目的　探讨图像融合影响因素及融合成像对诊断脑肿瘤的临床价值。方法　对 3 9例脑肿瘤患者2 0 1Tl SPECT和增强MR图像进行融合成像处理。结果　融合成像精度影响因素包括 :体位、解剖位置融合时基准的选择是否正确、MRI矢状面视野的大小以及SPECT彩色窗的调节。融合成像可以同定2 0 1Tl集聚部位、明确2 0 1Tl在肿瘤内集聚位置、鉴别集聚灶性质以及确认小病灶 ,对 2 8.2 % ( 11/3 9)病例诊断有帮助。结论　2 0 1Tl SPECT和MRI融合成像可提高脑肿瘤的诊断精度 ,有助于确定活检部位     

Specificity of SPIO particles for characterization of liver hemangiomas using MRI

We investigated the specificity of superparamagnetic iron oxide (SPIO)â€enhanced T1-weighted spin-echo (SE) magnetic resonance (MR) images for the characterization of liver hemangiomas. When imaging liver hemangiomas, which are the most frequent benign liver tumors, a method with very high specificity is required, which will obviate other studies, follow-up, or invasive diagnostic procedures such as percutaneous biopsy. Eighty-three lesions were examined by MR imaging at 1.5 T before and after intravenous injection of SPIO particles. Lesions were categorized as follows according to the final diagnosis: 37 hemangiomas, nine focal nodular hyperplasias (FNHs), 19 hepatocellular carcinomas (HCCs), and 18 metastases. Their signal intensity values were normalized to muscle and compared. The only lesions showing a significant increase in signal intensity ratio (lesion to muscle) on postcontrast T1-weighted SE images were hemangiomas (p < 0.001). The signal intensity ratio of hemangiomas increased on average by 70%. Based on receiver operating characteristic analysis and using a cutoff level of 50% signal increase, the specificity and sensitivity of SPIO-enhanced MR imaging for the characterization of hemangiomas would be 100% and 70%, respectively. The T1 effect of SPIO particles can help differentiate hemangiomas from other focal liver lesions such as FNHs, HCCs, and metastases and may obviate biopsy. When using SPIO particles for liver imaging, it is useful to add a T1-weighted sequence to T2-weighted images, thereby providing additional information for lesion characterization.     

小儿骶尾部畸胎瘤的MR诊断

目的探讨小儿骶尾部畸胎瘤的MR表现,评价MR的诊断价值。方法对15例经MR检查的患儿,进行回顾性分析。结果其中2例患儿肿瘤位于臀部生长．以囊性为主,呈圆形或椭圆形,内可见分隔,并可见脂肪信号,增强扫描可见囊壁及间隔强化;1例肿瘤全部位于盆腔内生长,呈囊实性混杂信号,增强可见实性部分、囊壁及间隔明显不均匀强化;12例可见肿瘤瘤体大部分位于盆腔内,小部分位于臀部生长,瘤内以囊性为主的囊实性混杂信号,增强扫描性实性部分囊壁及间隔有强化。结论MR检查能准确的显示小儿骶尾部畸胎瘤的位置和形态,有助于骶尾部畸胎瘤的诊断和良恶性的鉴别,并可以帮助临床选择合适的手术方式,对该病的诊断和治疗有重要意义。     

胰岛细胞瘤的MRI表现与鉴别诊断

目的探讨MRI在胰岛细胞瘤诊断和鉴别诊断中的价值。方法回顾性分析病理证实的9例胰岛细胞瘤的MRI表现特点。MRI检查包括SET1WI、抑脂FSET2WI和FSPGR动态增强扫描。结果9例在MRI共发现10个病灶,1例无功能胰岛细胞瘤有2个病灶。抑脂T2WI高信号(7/10),抑脂FSPGRT1WI低信号(7/10)。三期明显强化(4/10);动脉期强化不明显,静脉和平衡期强化逐渐明显(4/10);环形强化(2/10)。结论MR检查在胰岛细胞瘤诊断和鉴别诊断中有重要价值。