CT与MRI融合技术在脑动静脉畸形三维适形放射治疗中的应用

目的：探讨CT与MRI融合技术在脑动静脉畸形三维适形放射治疗中的应用价值。方法：选择脑动静脉畸形42例，术前均先行颅脑MRI薄层扫描及CT定位扫描，然后将CT和MRI图像资料进行图像配准和融合，根据融合后图像进行准确定位后再行三维适形放射治疗。结果：所有病变位置与范围在图像融合后均能显示清楚，经检测，所有融合图像的最大误差均〈1mm，全部病例均在融合图像协助下顺利完成治疗，未出现因定位失误而引发的并发症。结论：CT和MRI图像融合技术能提高颅内病变三维适形放射治疗的效果。     

快速磁共振成象—新差阶回波程序初步检查

作者用新差阶回波法(快MRI)检查颅内病灶60例。本法为自旋回波法取消180°高频脉冲,通过自旋调焦与转换差阶方向,及使脉冲激发角限于10～90。内的设计而成。成象时间缩短至5～40秒。对颅内病灶与自旋回波法成象的价值比较:①快MRI无诊断价值者18例,为脑多发性硬化、梗塞残余、神经胶质瘤、脑膜瘤及脑转移瘤等。脑转移瘤及1例听神经鞘瘤静注钆-DTPA后,信号增加,快速MRI可识别;②快速MRI诊断价值较差者24例,缺点在于不能可靠地确定病变范围。计垂体腺瘤9例,其中7例使用造影剂后信号增加,但仍不能识别全部范围。神经胶质瘤、转移瘤及脑膜瘤等13例,其中12例用造影剂后8例成象较佳。余1例梗塞,1例蛛网膜囊肿;③诊断价值良好者18例:除垂体瘤     

颅内节细胞胶质瘤的MRI表现

目的 分析探讨颅内节细胞胶质瘤的MRI表现,以期提高MRI对颅内节细胞胶质瘤的诊断价值.方法 对14例经病理证实颅内节细胞胶质瘤的MRI征象、临床资料及病理所见进行回顾性分析.结果 病变位于额叶5例,颞叶3例,小脑2例,脑室内1例,丘脑1例,松果体区1例,鞍上池1例;平均直径5.3 cm;囊性5例,实性9例;所有实性病灶均无水肿,边界清楚;病变呈轻中度强化者7例,明显强化者7例.结论 MRI表现为囊性壁结节且明显强化的病灶或实性、轻度强化且无水肿的病灶,以及CT扫描提示的病灶内钙化则可高度提示颅内节细胞瘤的可能性.     

颅内病变686例 X 刀治疗时头环安置体会

安置立体定向头环是X刀治疗的第 1个环节 ,其位置是否适当将直接影响影像定位质量。近 10年来 ,我院采用自行研制的X刀系统[1] 及德国Leibinger FischerX刀系统共治疗颅内病变 6 86例。现对头环安置体会报告如下。1　临床资料1 1　一般情况　男 376例 ,女 310例 ;年龄 4～ 83岁 ,平均 4 2 9岁。脑胶质瘤 198例 ,脑膜瘤 110例(115个 ) ,垂体腺瘤 6 3例 ,实质性颅咽管瘤 3例 ,神经鞘瘤 6 6例 ,脑转移瘤 15 2例 (96 2个 ) ,脑血管畸形 84例 ,血管网织细胞瘤 5例 ,松果体瘤 4例 ,脑恶性淋巴瘤 1例。1 2　术前准备　头部不备皮 6 6 1例 ,备皮 …     

颅内神经节细胞胶质瘤的影像诊断(附9例报告)

目的探讨颅内神经节细胞胶质瘤(gangloglioma,GG)的CT和MRI影像学特征。方法 9例患者行MR和CT检查后经手术和病理确诊为颅内神经节细胞胶质瘤。结果 9例病灶均为单发,其中3例位于额叶,3例位于颞叶,顶叶、枕叶及侧脑室各1例。囊实性病变5例,囊性病变2例,实性病变2例。MRI扫描肿瘤T1WI囊性部分呈低信号,实性部分呈等或低信号; T2WI上囊性部分呈高信号,实性部分呈等或高信号。6例无瘤周水肿,1例有轻度瘤周水肿,2例有中度瘤周水肿。结论颅内神经节细胞胶质瘤的CT和MRI影像学表现具有一定特征性,有助于提高对GG的鉴别诊断。     

MRI动态扫描对垂体微腺瘤的诊断价值

目的:探讨MRI动态扫描对垂体微腺瘤的诊断价值。材料与方法:垂体微腺瘤患者30例均经PHILIP 1.0 NT型MR机行常规矢状面、冠状面T_1WI和T_2WI检查,而后全部又经动态扫描。结果:本组30例的病灶在平扫中,T_1WI呈低信号、T_2WI呈高信号者25例;T_1WI呈等信号、T_2WI呈高信号者3例;T_1WI和T_2WI均呈等信号者1例及高信号者1例。微腺瘤形态征象有垂体柄偏斜(25例)、垂体中央向上膨隆(2例),鞍底下陷(2例),以及瘤内出血(1例),动态扫描后,病灶不增强而正常腺体增强且边界清楚者29例,仅有1例病灶内出血且边界不清楚。结论:MRI动态扫描对垂体微腺瘤的诊断敏感性显著高于平扫,而且它可完整地观察早期正常垂体的增强表现与垂体微腺瘤的增强延迟表现,因而,它有助于对垂体微腺瘤的准确定位,提高诊断准确率。     

颅内神经元及混合性神经元肿瘤的临床特征与MRI、CT

目的:增进对颅内神经元及混合性神经元肿瘤的临床特征与MRI、CT表现的进一步认识.材料和方法:对18例术前误诊而术后病理证实为颅内神经元及混合性神经元肿瘤的临床资料及影像学资料进行回顾性分析.结果:18例病人中节细胞胶质瘤9例,术前MRI及CT表现无明显特征性表现,分别误诊为胶质瘤(6例)、脑膜瘤(2例)及颅咽管瘤(1例).胚胎发育不良性神经上皮瘤(DNTS)4例,CT与MRI表现为病变分布大脑皮质(2例)同时累及白质(2例),病灶呈方形或三角形,无占位效应,无瘤周水肿,MRI示长T1长T2信号,T2WI有时呈混合信号,2例增强后不强化,术前误诊为软化灶(3例)和胶质瘤(1例);多纤维组织婴儿节细胞胶质瘤(DIG)2例,病灶呈囊实性伴钙化,术前误诊为髓母细胞瘤和少枝胶质瘤;中枢神经细胞瘤3例,术前误诊为脑膜瘤和脉络丛乳头状瘤.结论:颅内神经元及混合性神经元肿瘤临床上有一定的特征性,影像表现上极易误诊为脑内其他肿瘤,需仔细分析影像上某些特征性MRI与CT表现才得以诊断.     

对胸部病变的定位价值对胸部病变的定位价值

目的　探讨18F 脱氧葡萄糖 (FDG)PET发射和透射扫描图像融合对胸部病变的定位价值。方法　对 2 1例胸部肿瘤患者进行18F FDGPET肿瘤显像 ,图像重建后获得透射扫描和衰减校正后发射扫描各断面断层图像。计算机自动生成发射和透射扫描各断面断层图像双肺胸膜轮廓 ,采用表面轮廓匹配法进行图像融合。结果　在PET胸部透射扫描断层图像上可分辨出主动脉弓、气管、肺门大血管、心脏、肺组织、纵隔、胸壁等解剖结构。 2 1例患者在PET和CT图像上均检出的病灶共6 1个 ,与CT图像病灶位置对比 ,除后纵隔近脊柱旁 1个病灶在融合图像上难以定位外 ,余病灶均能正确定位。CT和融合图像相应横断面图像上病变中心点离胸壁前、后径和左、右径距离的平均差值分别为 (2 7± 0 8)、(2 4± 0 9)、(2 9± 0 5 )和 (2 1± 0 4)mm。结论　PET胸部发射和透射扫描图像融合对胸部病变可作出正确定位。PET透射扫描不仅可用于衰减校正 ,还可用于图像融合 ,提供胸部解剖结构信息。     

肝局灶性病变CT与MRI动态增强对照研究

目的:探讨肝局灶性病变在CT和MRI动态增强中的影像差异及其原因,以提高对CT及MRI各自动态增强表现的认识。方法:搜集17例肝脏局灶性病变患者的临床资料,其中7例肝细胞肝癌,5例海绵状血管瘤,2例腺瘤,2例局灶结节性增生,1例转移瘤。全部病例均分别行CT及MRI的平扫和三期动态增强扫描;MRI采用SE序列加快速扰相梯度回波序列,将CT和MR动态增强图像进行对照观察,包括动态增强各期的强化范围、强化方式和强化幅度,强化幅度的比较用病灶密度(信号)与肝脏密度(信号)的比值进行比较。结果:肝癌、腺瘤和局灶结节性增生在CT与MRI上强化范围相似。1例肝癌动脉期强化幅度MRI大于CT,3例肝癌和2例局灶结节性增生门脉期及延迟期强化幅度MRI大于CT,2例腺瘤增强各期强化幅度MRI均大于CT,以动脉期差异最大。5例海绵状血管瘤强化范围动脉期及门脉期MRI大于CT,延迟期则相仿。1例转移瘤CT增强各期均未见明显强化,MRI门脉期及延迟期可见环状强化。结论:肝局灶性病变CT与MRI动态增强表现存在一定的差异,主要表现为部分病变增强各期强化幅度MRI大于CT,尤以动脉期差异最大;部分病变增强范围MRI大于CT。     

X-刀治疗颅内病变的CT定位

目的 :探讨 X-刀治疗颅内病变 CT定位的方法。方法 :CT定位 X-刀治疗颅内肿瘤及动静脉畸形 337例 ,采用 FN-89或 Fischer立体定向仪 ,Somatom- DR CT机扫描定位 ,X-刀治疗软件根据 CT系列图像自动优化计划治疗。结果 :所有 X-刀治疗的病灶均采用 CT定位 ,靶点确定均一次到位。结论 :CT定位行 X-刀治疗颅内肿瘤及动静脉畸形是一种安全有效的方法     

Sensitivity of PET/MR images in liver metastases from colorectal carcinoma

Our aim was to evaluate the sensitivity of positron emission tomography/magnetic resonance image (PET/MRI) in the detection of liver metastases in patients from colorectal cancer as compared with computed tomography (CT), magnetic resonance imaging (MRI), PET and PET/CT images. From April 2008 to April 2010, twenty-four patients (mean age 56.5±10.5 years) with liver metastases from colorectal cancer diagnosed by pathology were retrospectively studied as above. All image data were respectively collected and fused. PET/CT and PET/MRI fusion images were successfully performed with a PET-MR-CT robot transmission-fusion imaging system. Pathologic findings and clinical follows-up were performed as referenced standards. Images were reviewed independently by at least three experts. We found a total number of 121 metastatic lesions and 35 of them, with a maximum diameter less than 1cm. According to a per-lesion analysis, the sensitivity on liver metastases was 64.5%, 80.2% and 54.5% on CT, MRI and PET, respectively. Based on reconstruction imaging analysis, PET/CT and PET/MRI showed sensitivities of 84.2% and 98.3%. Sensitivity comparison of PET/MRI had superior sensitivity of 98.08%. Paired data analysis (McNemar) resulted a type I error which equated to 0.05. There was a statistically significant difference between CT and MRI or PET for the detection of patients with liver metastatic lesions (P<0.05). However, PET/MRI can efficiently detect more metastatic lesions than PET/CT (P<0.05) among those with diameter <1cm. In conclusion, PET/MRI was a quite efficient diagnostic modality compared to conventional imaging modalities and should be considered the procedure of choice in the detection of liver metastatic lesions from colorectal cancer.     

脑脊液鼻漏的CT及MRI的检查技术和表现

目的 探讨联合冠状薄层CT及磁共振3D重T2水成像在评价脑脊液鼻漏的价值.方法收集临床确诊自发性脑脊液鼻漏的病人4例.男2例,女2例.所有病人均行CT检查,采集层厚0.625 mm,采用骨算法、无间隔采集.4例行MRI检查前颅凹底冠状薄层 3D FSE 重T2WI,TR/TE 5000 ms/119 ms.结果 4例自发性脑脊液鼻漏病人均行手术修补治疗.CT显示骨质缺损,MRI显示颅腔内脑脊液直接与鼻腔相通,其中1例MRI还显示垂体膨出至蝶窦.结论对自发性脑脊液鼻漏,CT可显示有无骨质缺损或骨折线,MRI可清晰显示漏口的位置.     

磁共振成像与CT图像融合技术在喉癌精确放疗定位中的初步应用

目的 探讨磁共振成像(MRI)和CT图像融合技术对喉癌精确放疗定位的应用价值及意义.方法 对10例经内镜及手术病理证实的喉癌患者行图像融合,先行CT定位薄层扫描,然后行颈部MRI定位薄层扫描,最后将MRI图像资料拷贝至图像融合工作站进行配准和融合.结果 所有病变在融合的图像上均能清楚显示并配准满意,MRI薄层扫描可以大大弥补CT定位扫描中软组织分辨率低,病变显示范围不足的缺点,对进一步精确放疗提供可靠的信息.结论 MRI薄层扫描可以弥补CT定位图像在喉部软组织病变的显示不清晰的缺点,提高了喉癌放疗定位的精确性.     

PET/CT诊断恶性肿瘤及其转移灶的价值

目的探讨PET／CT对恶性肿瘤及其转移灶的检测效能。方法恶性肿瘤患者65例皆行PET／CT检查，原发灶皆经病理组织学确诊，转移灶的诊断综合组织病理学结果及多种影像学检查而定。行^18F-脱氧葡萄糖(FDG)PET／CT融合图像、唧图像和CT图像帧对帧对比分析。结果初诊恶性肿瘤患者59例，有恶性病灶264个。264个病灶中，唧与平扫CT阅片均有肯定诊断结论者128个，占48．4％；而唧有肯定诊断结论，但CT难以有肯定诊断结论者111个，占42．0％；唧显像为阴性或难以确定，而CT有肯定诊断结论者11例共25个病灶．占9．6％。PET／CT的总检出率高于PET和CT。6例治疗后患者，CT难以确定肿瘤残余和坏死区域，而PET／CT能清楚区分。结论PET／CT可提高对恶性肿瘤诊断及分期的准确性。     

The usefulness of 18F-FDG PET/MRI fusion image in diagnosing pancreatic tumor: comparison with 18F-FDG PET/CT

Purpose

This study aimed at demonstrating the feasibility of retrospectively fused ¹⁸F FDG-PET and MRI (PET/MRI fusion image) in diagnosing pancreatic tumor, in particular differentiating malignant tumor from benign lesions. In addition, we evaluated additional findings characterizing pancreatic lesions by FDG-PET/MRI fusion image.

Methods

We analyzed retrospectively 119 patients: 96 cancers and 23 benign lesions. FDG-PET/MRI fusion images (PET/T1 WI or PET/T2WI) were made by dedicated software using 1.5 Tesla (T) MRI image and FDG-PET images. These images were interpreted by two well-trained radiologists without knowledge of clinical information and compared with FDG-PET/CT images. We compared the differential diagnostic capability between PET/CT and FDG-PET/MRI fusion image. In addition, we evaluated additional findings such as tumor structure and tumor invasion.

Results

FDG-PET/MRI fusion image significantly improved accuracy compared with that of PET/CT (96.6 vs. 86.6 %). As additional finding, dilatation of main pancreatic duct was noted in 65.9 % of solid types and in 22.6 % of cystic types, on PET/MRI-T2 fusion image. Similarly, encasement of adjacent vessels was noted in 43.1 % of solid types and in 6.5 % of cystic types. Particularly in cystic types, intra-tumor structures such as mural nodule (35.4 %) or intra-cystic septum (74.2 %) were detected additionally. Besides, PET/MRI-T2 fusion image could detect extra benign cystic lesions (9.1 % in solid type and 9.7 % in cystic type) that were not noted by PET/CT.

Conclusions

In diagnosing pancreatic lesions, FDG-PET/MRI fusion image was useful in differentiating pancreatic cancer from benign lesions. Furthermore, it was helpful in evaluating relationship between lesions and surrounding tissues as well as in detecting extra benign cysts.     

SPECT／CT图像融合显像定位诊断异位或转移性嗜铬细胞瘤的应用价值

目的:为临床手术治疗异位或恶性嗜铬细胞瘤转移灶提供定性和准确解剖定位.材料和方法:对临床怀疑嗜铬细胞瘤的131例患者行131I-MIBG全身显像,发现其中10例肾上腺以外部位有异常放射性浓聚区,对该部位进行SPECT/CT同机图像融合断层显像,分别获得SPECT发射断层图像、CT透射断层图像及准确定位的融合图像.结果:对131I-MIBG全身显像发现异位及恶性嗜铬细胞瘤转移灶,不能明确解剖定位的病例,经SPECT/CT图像融合断层显像后,均获得明确的准确解剖定位.结论:SPECT/CT图像融合显像能够定性并准确定位异位或转移性嗜铬细胞瘤,为临床手术治疗提供重要的依据.     

CT/MRI图像融合技术在颅底肿瘤检查中的应用价值

目的：探讨CT/MRI图像融合（image fusion）技术在颅底肿瘤检查中的应用价值。方法：搜集经MRI检出并均行高分辨率CT扫描的颅底肿瘤患者33例,将同一患者的CT、MRI图像融合。两名高年资放射科医师共同协商评价CT/MRI融合图像、MRI图像,评价的内容包括病变内部的密度或信号、病变的轮廓、病变与邻近血管的关系、病变与周围神经的关系、病变邻近骨质的破坏或硬化情况、病变周围软组织的改变,依据两种图像所能显示的病变信息等级评分,采用配对t检验分析比较的结果。结果：与单独MRI图像相比,CT/MRI融合图像在显示病变内部结构及其与周围血管、神经的关系方面无明显优势（P〉0.05）;而在病变的轮廓、邻近骨质的改变情况方面明显优于单独MRI图像（P〈0.05,P〈0.01）。结论：CT/MRI融合图像显示病变的综合信息明显优于单独的MRI图像,能够直观地为临床提供更加全面的信息。     

Initial application of respiratory-gated 201Tl SPECT in pulmonary malignant tumours

AIM: Respiratory-gated thallium-201 chloride (201Tl) single photon emission computed tomography (SPECT) was used in preliminary investigations to reduce the adverse respiratory motion effects observed on standard ungated SPECT images and to obtain reliable fusion images with computed tomography (CT) in patients with malignant lung tumours. METHODS: Fifteen patients with primary lung cancer (n=10) or metastatic lung tumours (n=5) underwent gated SPECT 20 min after intravenous injection of 148 MBq 201Tl, using triple-headed SPECT and laser light respiratory tracking units. Projection data were acquired by a step and shoot mode, with 20 stops over 120 degrees for each detector and a preset time of 30 s for each 6 degrees stop. Gated end-inspiratory and ungated images were obtained from 1/8 data centred at peak inspiration for each regular respiratory cycle and for the full respiratory cycle data, respectively. The degree and size of tumour 201Tl uptake were compared between these images by regions of interest (ROI) analysis. Gated SPECT images were registered with rest inspiratory CT images using an automated three-dimensional (3D) image registration tool. Registration mismatch was assessed by measuring the 3D distance of the centroid of 14 201Tl-avid peripheral tumours. Attenuation correction of gated SPECT images was performed using CT attenuation values of these fusion images. RESULTS: Gated SPECT images improved image clarity and contrast of tumour 201Tl uptakes compared with ungated images, regardless of the decreased count density due to the use of gated images. The lesion-to-normal (L/N) lung count ratios and ROI size in 18 well-circumscribed 201Tl-avid tumours were significantly higher and smaller on gated images (both P<0.0001). Gated images showed positive 201Tl uptakes in two small peripheral tumours, although negative on ungated images, and demarcated 201Tl-avid tumours from adjacent 201Tl-avid lymph node or surrounding focal 201Tl uptakes caused by other pathology, although these were not clearly demarcated on ungated images. On fusion images, gated images yielded a significantly better SPECT-CT matching compared with ungated images (P<0.0001). Fusion images accurately localized 201Tl uptakes of tumour/lymph node and other focal pathological/physiological conditions. Attenuation-corrected gated SPECT images further facilitated the detection of 201Tl uptake in small or deeply located lesions, with significantly increased L/N ratios. CONCLUSION: Gated SPECT images facilitate the detection of tumour 201Tl uptake and provide reliable SPECT-CT fusion images, which contribute to accurate interpretation and attenuation correction of Tl SPECT images.     

儿童神经母细胞瘤颅面骨转移的CT和MRI表现

目的：探讨神经母细胞瘤颅面骨转移的CT和MRI特征性表现。方法：回顾性分析6例经病理证实的神经母细胞瘤颅面骨转移患者的CT和MRI资料,分析其影像学特征。6例均行头颅CT平扫,其中2例行头颅MRI平扫和增强检查,6例中5例行腹部CT平扫及增强检查,1例行腹部MRI平扫及增强检查。结果：6例均为双侧颅面骨受累,主要CT表现为颅面骨骨质破坏、骨膜下垂直骨针和软组织肿块,软组织肿块中可见钙化;主要MRI表现为颅骨骨质破坏并软组织肿块,其内有钙化灶,肿块于T1WI上呈等信号,T2WI呈稍高信号,增强后可见肿块和邻近脑膜有不均匀轻度强化。5例腹部CT显示腹膜后肿块并钙化,增强后有不均匀强化。1例MRI显示腹膜后肿块。结论：神经母细胞瘤颅骨转移的CT和MRI表现有一定特征性,CT和MRI对本病的诊断有重要价值。