Meningioma of the third ventricle

Summary Meningiomas of the third ventricle are rare intracranial neoplasms. We reported such a case in a 42 years old man without clinical evidence of increased intracranial pressure. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated the tumour sitting in the superior and anterior part of the third ventricle, bulging into the lateral ventricles. CT was more effective than MRI in the demonstration of calcifications whereas MRI proved to be superior in delineation of the tumour and its relation with surrounding structures.     

Intracranial meningiomas: How frequent are indicative findings in CT and MRI?

Summary Frequencies of CT and MRI findings characteristic of meningiomas were compared in 50 cases. Plain and contrast enhanced examinations with CT and MRI were evaluated retrospectively regarding 12 criteria known to be indicative of the diagnosis of meningiomas. CT proved to be superior in demonstrating calcifications and a typical tumor density. On the other hand, MRI was better suited for identifying the extraaxial location of tumors, the broad contact of tumors to the meninges, tumor capsules and meningeal contrast enhancement adjacent to the tumor. Both methods provided nearly equal results in demonstrating mass effects, hyperostoses, intensive and homogeneous contrast enhancement, and smooth tumor contours after contrast administration. On the whole, neither of the two methods demonstrated a universal superiority for the diagnosis of intracranial meningiomas. Rather, each method displayed distinct advantages.     

颅骨表皮样囊肿的CT及MRI特征

目的探讨颅骨表皮样囊肿(SEC)的CT和MRI影像学特点,以提高对该病的认识。资料与方法回顾性分析10例经手术病理确诊的SEC的CT及MRI表现。9例行CT平扫;8例行MRI检查,其中6例包含扩散加权成像(DWI)序列。8例MRI检查中2例行MRI平扫,4例行MRI平扫加增强检查,2例只行MRI增强检查;其中7例同时行CT及MRI检查。结果病变均为单发,起自板障。9例CT平扫示颅骨呈膨胀性改变,7例密度不均,其中5例病变可见钙化;2例病变密度均匀。6例MRI平扫,4例呈以长T1、长T2为主混杂信号,1例呈均匀长T1、长T2信号,1例呈短T1、长T2信号。6例DWI序列中5例呈高信号,1例呈低信号;表观扩散系数(ADC)图重组后,1例呈稍高信号,1例呈高信号,4例呈稍低信号。6例MRI增强检查,2例病变无强化;4例病变内部和/或边缘强化,同时1例邻近硬膜明显强化。结论SEC的CT及MRI表现有一定的特征性,影像学检查有助于其定位及定性诊断。     

中枢神经系统血管外皮细胞瘤的CT、MRI表现

目的探讨中枢神经系统血管外皮细胞瘤(hemangiopericytoma,HPC)的CT、MRI影像学特征.方法回顾性分析经手术、病理证实的9例中枢神经系统HPC的CT、MRI影像学特征,结合文献报道总结本病的诊断与鉴别诊断要点.结果9例中颅内7例,椎管内2例.CT平扫4例呈均匀略高密度,3例呈略高、低混杂密度;MRI检查4例呈等T1、等T2信号,3例呈等长T1、等长T2混杂信号.CT、MRI增强后所有病灶均呈明显强化.结论CT、MRI可对中枢神经系统HPC做出可靠诊断.     

MR增强后液体衰减反转恢复序列对脑转移瘤的诊断价值

目的 分析MR增强后液体衰减反转恢复(fluid attenuated inversion recovery,FLAIR)序列对脑转移瘤的诊断价值. 资料与方法 确诊恶性肿瘤可疑有脑转移患者159例.MR检查除常规平扫和增强外,在增强后加扫FLAIR序列,图像由3名有经验的放射科医师评估. 结果 58例有脑内转移,6例增强后FLAIR脑实质病灶数目显示较增强T1WI多,11例病灶强化较T1WI明显;在11例柔脑膜转移者中,7例病灶强化程度优于增强后T1WI. 结论 增强后FLAIR是增强后T1WI的有效补充,对脑内小病灶和脑膜病灶更敏感.     

Radiotherapy of Liver Metastases

PURPOSE: To assess differences in delineated target volumes of liver metastases using contrast-enhanced CT and different MRI sequences for radiation treatment planning. PATIENTS AND METHODS: 25 patients with 43 colorectal liver metastases were recruited. Tumor margins were defined by two experienced radiologists. The resulting D90 was assessed and the CT-based 3-D dose distribution merged with the according MRI dataset by employing image fusion. A theoretical D90 as a result of MRI-based treatment planning was assessed for various MRI sequences individually. RESULTS: In venous phase contrast-enhanced CT, the mean tumor volume was 20 ml; T1-weighted (T1w) MRI, 27 ml; contrast-enhanced T1w 42 ml; T2w 65 ml. The difference between the target volumes as assessed by either CT or MRI was 181% for T1w images, 178% for contrast-enhanced T1w, and 246% for T2w sequences. All differences were statistically significant (p < 0.05). The analysis of the dose-volume histograms revealed statistically significant differences (i.e., for the D90) for the different target volumes specified by CT and MRI: mean D90 on CT, 18 Gy; plain T1w, 16 Gy; contrast-enhanced T1w, 15.5 Gy; T2w, 12 Gy. Hence, delineation of a larger target volume in T2w MRI compared to contrast-enhanced CT resulted in a smaller D90. The mean differences of tumor volumes assessed by CT and plain T1w were significantly higher in the group of patients showing local tumor recurrences as compared to patients with long-term local tumor control (p = 0.002). CONCLUSION: For treatment planning of liver metastases, the use of either plain T1w or T2w sequences is recommended to delineate the clinical target volume as completely as possible and not to miss potential tumor cell congregations in the surroundings as in CT.     

脑颜面血管瘤病的MRI和CT诊断

目的:探讨脑颜面血管瘤病的CT和MRI表现,并评价其临床价值。方法:回顾分析经临床和CT、MRI证实的8例脑颜面血管瘤病临床及CT、MRI资料。结果:CT显示患侧皮质钙化8例,脑萎缩6例,患侧脑室脉络丛增大1例,颅骨增厚2例。MRI扫描显示沿皮层弧形低信号3例,5例增强检查软脑膜呈线样强化。结论:CT对脑颜面血管瘤病的诊断有重要价值,MRI可以帮助诊断。     

钝性肝脾肾损伤的CT平扫与增强扫描比较

目的:比较CT平扫与增强扫描对肝脾肾钝性损伤的诊断能力。方法:回顾性分析临床疑似钝性肝脾肾损伤,并经手术和临床观察证实的CT平扫和增强扫描的患者84例。结果:平扫确定的损伤:肝12例,脾25例,肾5例;平扫可疑损伤:肝22例,脾15例,肾5例。增强确定的损伤:肝32例,脾40例,肾12例(全肾梗塞1例,局限性梗塞3例);对比剂外溢(活动性出血)3例;无可疑损伤。平扫无异常而增强确定有损伤:肝10例,脾5例,肾2例。增强显示的损伤灶比平扫范围明显大、病灶多、界限清楚。结论:CT增强扫描显示肝脾肾损伤明显优于平扫,延时扫描有助于发现活动性出血,应常规增强扫描。     

脑血吸虫病的CT与MRI诊断对比研究

目的：研究脑血吸虫病的CT、MRI表现，并探讨两种检查方法对该病的诊断价值。方法：本组28例患者均同时行CT、MRI检查(平扫 增强)，分析该病的影像学征象并结合9例手术病理资料进行对比。结果：27例有不同程度的水肿；22例呈水肿伴不规则结节，增强后呈结节状、斑片状及融合成簇状强化；CT发现54个病灶．MRI发现75个病灶。结论：脑血吸虫病在CT及MRI增强扫描中都具有特异性表现，MRI信号更接近其病理改变；两种检查方法郜具有重要的临床价值，但MRI明显优于CT。     

Low dose non-enhanced CT versus standard dose contrast-enhanced CT in combined PET/CT protocols for staging and therapy planning in non-small cell lung cancer

PURPOSE: To evaluate low dose non-enhanced CT and standard dose contrast-enhanced CT in combined PET/CT protocols for staging and therapy planning of non-small cell lung cancer (NSCLC). METHODS: Retrospective analysis was performed of 50 consecutive patients with proven NSCLC who had been referred for primary staging (n=41) or restaging (n=9). All patients underwent a multi-phase PET/CT consisting of a low dose non-enhanced attenuation scan and an arterial and portal-venous contrast-enhanced CT scan followed by whole-body PET. Fused datasets of non-enhanced and contrast-enhanced PET/CT were compared per patient by using the TNM staging system, and per lesion regarding localisation, characterisation and delineation of tumour lesions. The staging results were validated either by histopathology or by clinical-radiological follow-up for >or=6 months. RESULTS: In 47/50 patients, the results of T staging did not differ between the two PET/CT protocols. Three patients could only be correctly classified as having T4 tumours after contrast application. Regarding N staging, both protocols yielded the same results. In M staging, there was only one patient with an improvement of the results as a result of contrast application. The lesion-based analysis of 92 sites showed no difference in the accuracy of lesion localisation and only one revision of lesion characterisation by contrast-enhanced PET/CT. The assessment of tumour delineation was altered by contrast application in 58/92 sites (p<0.0001). In 10/50 patients, contrast-enhanced PET/CT detected additional clinically important findings. CONCLUSION: In patients with advanced NSCLC, contrast-enhanced CT as part of the PET/CT protocol more accurately assessed the TNM stage in 8% of patients compared with non-contrast PET/CT. However, for planning of 3D conformal radiotherapy and non-conventional surgery, contrast-enhanced PET/CT protocols are indispensable owing to their superiority in precisely defining the tumour extent.     

Giant-cell tumour of the sphenoid bone: case report

We report an 18-year-old woman with a giant cell tumour of the sphenoid bone. CT demonstrated a lytic soft-tissue mass arising from the sphenoid body, extending to the left petrous apex and into the nasopharynx. On MRI the tumour had nonspecific signal intensity, but there was contrast enhancement on both examinations. CT was better for showing the extent of the osseous disease, whereas MRI was more accurate as regards soft-tissue extension. Received: 15 May 1995 Accepted: 26 December 1995     

胸膜外孤立性纤维瘤的影像表现与病理对照研究

目的:分析总结胸膜外孤立性纤维瘤的影像表现及病理基础,提高诊断准确性。方法:回顾性分析30例经病理证实的胸膜外孤立性纤维瘤的CT、MRI表现。5例患者仅进行了CT检查,19例患者仅进行了MR检查,6例同时行CT和MR检查。结果:30例患者均为单发病灶,其中13例位于中枢神经系统,7例位于头颈部、6例位于腹盆腔、1例位于食管、1例位于乳腺、1例位于腹股沟、1例位于耻骨。病灶多呈类圆形或长圆形,部分病例可见分叶或形态不规则。CT平扫颅内病灶呈不均匀等低密度或均匀稍高密度,其余病灶CT平扫呈均匀软组织密度。头颈部病灶T₁WI呈较均匀等低信号,其余病灶T₁WI呈欠均匀等低信号,T₂WI信号混杂,可见等、低、高信号;15例病灶边缘或病灶内可见血管流空信号。增强扫描颅内病灶呈明显不均匀强化,其余病灶呈中度到明显不均匀强化,腹盆腔病灶可见渐进性强化;T₂低信号区可见强化,坏死囊变区未见强化。免疫组化可见CD34、STAT-6、VIM、CD99、 Bcl-2阳性。结论:胸膜外孤立性纤维瘤分布广泛,病理基础决定其信号...     

Contrast enhanced magnetic resonance imaging of the brain using gadolinium-DTPA

This report concerns a clinical trial with gadolinium-DTPA (Gd-DTPA) as an intravenous contrast medium for magnetic resonance imaging (MRI) in patients with disorders of the central nervous system. Fifty patients, 30 females and 20 males, were examined without and with Gd-DTPA. The contrast medium was well tolerated by all patients. The results of MRI scanning without and with Gd-DTPA and those obtained with computed tomography (CT) using intravenous contrast enhancement were compared. This investigation comprised mainly patients with intracranial tumors, multiple sclerosis, and nasopharyngeal tumors. The results may be summarized as follows: 1) MRI with Gd-DTPA (MRI+) gave better results than MRI without Gd as regards delineation of the lesion, blood vessels and edema in cerebral tumors, pituitary adenomas and acute forms of multiple sclerosis (MS). 2) MRI+ was better than CT in 32 of the 50 cases examined; with intracerebral tumors it was better in 15 out of 18 cases. 3) MRI+ was always better than CT in patients with MS. In 3 out of 7 cases MRI demonstrated the acute MS lesions. 4) MRI+ seemed to have advantages also in nasopharyngeal tumors as ascertained from this limited experience.     

CT与MR对女性盆腔肿块诊断能力的对比研究

目的 分析女性盆腔肿块（FPM）的CT与MRI表现，并比较CT与MRI对FPM的诊断能力。方法 50例经手术病理证实的FPM（25例恶性和25例良性）患者均经常规CT与MRI检查。29例又经CT增强扫描，35例又经MRI增强扫描。结果 CT正确诊断恶性FPM15例和良性FPM18例，诊断敏感性60%，特异性72%，准确率66%。MRI正确诊断恶性FPM21例和良性FPM22例，诊断敏感性80%，特异性88%，准确率84%。CT增强扫描能显示常规扫描看不到的征象，如卵巢癌壁结节强化和卵巢囊腺瘤的壁与间隔轻度强化等。MRI增强扫描有类似发现。CT对囊性肿块的诊断与MRI相似，对钙化斑的显示优于MRI，但对囊实性肿块结构细节的显示不如MRI。结论 CT与MRI的诊断具有各自的优势，总的说来，MRI优于CT，然而，二者结合可明显提高诊断准确率。     

脑实质内海绵状血管瘤的影像学诊断

目的：探讨脑实质内海绵状血管瘤(CA)的CT、MRI、MRA认和DSA表现并比较四种影像学检查方法的诊断价值。方法：回顾性分析20例CA的影像学表现，其中15例经手术病理证实，5例经影像学及临床随访证实。20例进行CT和MRI平扫、MRA认，13例行CT增强扫描，15例行MRI增强扫描，12例行DSA检查。结果：CA可发生于脑内任何部位．以单发多见(17／20，占85％)。20例CA检出25个病灶。CT和MRI平扫均发现所有病灶。CA的CT平扫均表现为高密度或稍高密度；13例CT增强扫描发现15个病灶，其中10个病灶无强化，5个病灶轻度强化。CA的MRI平扫表现为T1WI呈等或低信号12个，高信号8个，混杂信号5个；T2WI全部病灶均表现为高低混杂信号，23个病灶周围伴有低信号环，2个病灶周围有水肿带，无占位效应；15例MRI增强扫描发现17个病灶，其中7个病灶出现瘤体血管床轻中度强化，2个病灶边缘强化，8个病灶无强化。20例CA行3D TOF MRA认均未见异常血管影。12例行全脑DSA检查未见供血动脉与引流静脉。4例表现为毛细血管期或静脉窦期富血管性病变。结论：CA具有较典型的影像学表现．CT和MRI平扫对明确诊断具有重要意义，且MRI优于CT；CA的CT和MRI增强扫描无特征性表现；MRA和DSA对诊断CA价值有限。     

颅内绒毛膜上皮癌的影像学表现

目的分析颅内绒毛膜上皮癌的影像学表现,提高其诊断符合率。资料与方法回顾性分析4例经病理证实的颅内绒毛膜上皮癌,4例均行MRI头颅平扫和增强扫描,使用Siemens Vision Plus 1.5 T或GE 3.0 SignaExite超导型磁共振扫描仪;2例行CT头颅平扫,1例行CT头颅平扫和增强扫描,采用Somatom Plus 4全身CT扫描机或GE Light Speed 16螺旋CT扫描仪。结果 4例人绒毛膜促性腺激素(HCG)均明显增高。3例颅内原发性绒毛膜上皮癌,均位于松果体区且均为男性;1例颅内继发性绒毛膜上皮癌,发生在脑实质内,为女性。CT扫描呈团块状或分叶状混杂密度影,内可见小点状或斑块状高密度钙化灶;增强扫描肿块呈轻中度强化。MRI呈不均匀混杂T1、T2信号,可见低信号含铁血黄素沉着及钙化,幕上脑室不同程度积水,增强扫描实性部分呈较明显不均匀强化。结论颅内绒毛膜上皮癌易发生肿瘤内出血或肿瘤卒中,结合临床特点及实验室检查可在术前作出较为准确的诊断,但最终确诊仍依靠病理及免疫组织化学。     

周围神经鞘瘤的CT和MRI分析

目的:分析周围神经鞘瘤的CT和MRI征象及病理组织学表现.方法:回顾性分析我院经手术病理证实的周围神经鞘瘤30例的CT和MRI征象及病理表现.结果:病变发生在颈部10例、胸部6例、腹部7例(含胃部4例)、四肢7例.30例周围神经鞘瘤中25例为良性,5例为恶性.20例行CT检查,其中17例良性病灶平扫密度较均匀,4例可见点状钙化灶,增强扫描病灶呈轻至中度强化,3例恶性病灶瘤体巨大,囊变、坏死多发,增强扫描强化不均匀.10例周围神经鞘瘤行MRI检查,MRI表现:T1WI病灶呈等或稍低信号,T2 WI呈高信号,增强扫描不均匀强化,10例病灶中,2例为恶性周围神经鞘瘤并伴淋巴结转移.结论:周围神经鞘瘤的CT和MR1表现具有特征性,CT和MRI能准确地显示肿瘤形态、部位、内部结构及与邻近结构的关系,对诊断有重要帮助,对手术治疗具有重要指导作用.     

肺血管外皮瘤的影像学诊断

目的　探讨肺血管外皮瘤的影像学表现。方法　分析 3例经病理证实的肺血管外皮瘤的CT、MRI表现。结果　 3例患者均表现为肺内单发的巨大肿块 ,CT平扫示密度不均匀 ,强化扫描示肿块实质明显强化 ,并可以见到其中异常强化的血管影。MRI平扫示肿块信号不均匀 ,并可以见到血管流空征象。结论　肺内单发的巨大肿块 ,CT强化扫描见到异常强化的血管 ,MRI扫描见到血管流空征象 ,可以高度提示肺血管外皮瘤的诊断     

Application of contrast agents in CT and MRI (NMR): their potential in imaging of brain tumors

Summary 21 patients with clinical and CT diagnoses of intracranial tumor were studied by MRI (NMR) prior to and after administration of intravenous Gadolinium-DTPA. Resultant MRI images were compared with corresponding CT sections with respect to lesion detection, contrast enhancement, tumor delineation and visualization of perifocal edema. All intracranial lesions shown on CT were identified on MRI. Contrast enhancement in MRI images was achieved in 19 out of 21 patients, as it was also with CT. In these cases improved differentiation between tumor, perifocal edema and adjacent brain structures were obtained. In most cases sufficient visualization of perifocal edema in MRI required T₂ weighted images (SE 1600/70) in addition to spin echo scans routinely performed prior to and after contrast medium (SE 400/30 or 800/30). No side effects were encountered following administration of Gadolinium-DTPA. The good tolerance and the efficacy justifies the use of Gadolinium-DTPA for contrast enhanced MRI imaging.Dedicated to Professor S. Wende on the occasion of his 60th birthday     

肝结核的CT及MRI表现(附2例报告及文献复习)

目的探讨肝结核的CT和MR I表现特点及其鉴别诊断。方法回顾性分析2例经病理证实的肝结核的CT和MR表现特点,并作文献复习。2例肝结核行CT平扫及CT动态增强扫描,1例行MR平扫。结果CT平扫1例呈不均质性低密度,病变内伴有更低密度坏死区,1例接近等密度;CT增强扫描动脉期2例病变均未见明显强化;静脉期及平衡期2例病变轻度强化,其中1例伴有坏死囊变区周边轻微环形强化。1例MR平扫,T1W I呈低信号,T2W I呈等高混杂信号。结论肝结核少见,易误诊,CT及MR I能显示肝结核的一些特征,尤其是动态增强扫描有助于该病的诊断和鉴别诊断。