Radiologic manifestations of peritoneal mesothelioma

We report four cases of histologically proved peritoneal mesothelioma and describe the radiographic (mainly CT and angiographic) findings. There were three malignant diffuse tumors and one benign localized tumor. In one case, the lesion extended to the omentum and entrapped the fat tissue, and differentiation from peritonitis carcinomatosa was difficult. In the other three cases, reflecting necrotic change within the tumor, CT showed hypodensity throughout most of the mass. In two cases with hemorrhage, CT showed hyperdensity in the center of the mass. Angiography showed slight or medium neovascularity in the periphery of the tumor, but most of the tumor was avascular. Angiography was helpful for topographic diagnosis, but it was difficult to make a specific diagnosis or differentiate between malignant and benign types. We emphasize that it is important to consider peritoneal mesothelioma in the differential diagnosis when a mass of unknown origin is found in the abdomen, particularly when it is accompanied by necrosis and hemorrhage.     

Neoplastic encephalopathy: dynamic CT of cerebral gliomata

Summary Intravenous contrast enhanced dynamic computed tomography of cerebral gliomata reveals a spectrum of patterns which reflect different degrees of neovascularity as well as a variable breakdown in the blood-tumor-barrier both intratumorally as well as between individual tumors. Phenomena not generally associated with gliomas including intrinsic neoplastic and peripheral cerebral hypoperfusion, hyperperfusion, and indications of vascular stealing are also demonstrated with this technique which conceivably explain and are partially responsible for certain aspects of the encephalopathy accompanying cerebral neoplasia. A comparison of the dynamic sequences with conventional selective cerebral angiography further indicates that the more contrast-sensitive dynamic method is potentially superior in the detection of subtle neovascularity.     

时间—密度曲线在常见脑肿瘤鉴别诊断中的应用价值

目的：探讨时间-密度曲线在常见脑肿瘤CT动态增强扫描后鉴别诊断中的应用价值。材料与方法：对46例脑瘤患者进行固定层面、时间、速度、剂量增强扫描,然后用CT功能软件——时间-密度曲线进行后处理并分析。结果：15例脑膜瘤平均峰值109HU,增强高度59.8HU,峰时97s,曲线以速升-亚速降-缓降型为主（60%）;19例胶质瘤平均峰值70.1HU,增强高度25.4HU,峰时223s,曲线以亚速升-缓升型为主（52.6%);转移瘤平均峰值74.5HU,增强高度33.5HU,峰时95.8s,曲线以速升-缓降型为主（67%）。结论：平均峰值与增强高度脑膜瘤与胶质瘤、转移瘤差别非常显著（P＜0.01),到达峰值时间,胶质瘤与脑膜瘤、转移瘤差别非常显著（P＜0.01)。各种肿瘤的时间-密度曲线表现不一,对肿瘤的鉴别诊断有很大价值。     

少见型脑膜瘤的CT诊断

目的探讨颅内少见型脑膜瘤的CT表现,并提高其诊断准确性。方法15例经手术病理证实的少见型脑膜瘤,包括Nauta型囊性脑膜瘤8例,恶性脑膜瘤4例,多发性脑膜瘤2例以及完全钙化性脑膜瘤1例,术前均经CT平扫,14例又经对比增强扫描。对所有患者的CT表现结合文献复习进行了回顾性分析。结果多数脑膜瘤位于幕上。Nauta型囊性脑膜瘤CT平扫呈囊实性肿块,增强扫描示肿瘤实质部分明显强化,部分囊壁有强化。恶性脑膜瘤CT平扫呈不规则形混杂密度肿块,或囊性肿块伴结节,肿瘤边缘不规则,增强后实质部分明显强化,瘤周水肿广泛。多发性脑膜瘤CT平扫示多发结节灶,增强扫描示肿瘤轻度强化。完全钙化性脑膜瘤CT平扫呈钙化团块,邻近颅骨骨质增生硬化,瘤周无水肿。本组CT术前正确诊断10例,误诊5例。结论颅内少见型脑膜瘤术前CT易误诊。综合分析各型的CT特征,有助于作出正确诊断和鉴别诊断。     

脑SPECT灌注显像在老年人脑血管疾病中的应用

目的：旨在研究脑SPECT血流灌注显像对老年脑血管疾病的诊断价值。材料和方法：对132例脑血管疾病患者进行脑SPECT血流灌注显像，并将SPECT结果与MRI、CT相比较。结果：脑梗塞患者96．1％有阳性发现，有些灌注减低灶较MRI，CT显示的范围大．可能由于包括了梗塞区及周围缺血半影区的缘故。对神经机能联系不能征象进行了观察．短暂性脑缺血发作患者在发作间期有61.9%阳性．病灶与发作期临床症状相符。脑供血不足、脑动脉硬化、脑出血的阳性率分别为64.3%、80%．95.5%。结论：脑SPECT灌注显像为老年人脑血管疾病的诊断提供了客观依据，有重要应用价值。     

Contribution of dynamic contrast MR imaging to the differentiation between dural metastasis and meningioma

Purpose To determine the perfusion-sensitive characteristics of cerebral dural metastases and compare them with the data on meningiomas.Methods Twenty-two patients presenting with dural tumor underwent conventional and dynamic susceptibility-contrast MR imaging: breast carcinoma metastases, two patients; colorectal carcinoma metastasis, one patient; lung carcinoma metastasis, one patient; Merkel carcinoma metastasis, one patient; lymphoma, one patient; meningiomas, 16 patients. The imaging characteristics were analyzed using conventional MR imaging. The cerebral blood volume (CBV) maps were obtained for each patient and the relative CBV (rCBV) in different areas was calculated using the ratio between the CBV in the pathological area (CBVp) and in the contralateral white matter (CBVn).Results The differentiation between a meningioma and a dural metastasis can be difficult using conventional MR imaging. The rCBVs of lung carcinoma metastasis (1 case: 1.26), lymphoma (1 case: 1.29), breast carcinoma metastasis (2 cases: 1.50,1.56) and rectal carcinoma metastasis (1 case: 3.34) were significantly lower than that of meningiomas (16 cases: mean rCBV = 8.97±4.34, range 4–18). Merkel carcinoma metastasis (1 case: 7.56) showed an elevated rCBV, not different from that of meningiomas.Conclusion Dural metastases are sometimes indistinguishable from meningiomas using conventional MR imaging. rCBV mapping can provide additional information by demonstrating a low rCBV which may suggest the diagnosis of metastasis.     

Computed tomography of germinomas in basal ganglia and thalamus

Summary CT findings of 6 cases with germinoma originating in the basal ganglia and thalamus are reported. The early finding of germinoma in this region on plain CT, was an irregularly defined, slightly high density area without mass effect. Repeated CT scanning showed enlarging iso-density lesion accompanied by mass effect to high. Intratumorous cysts and calcifications were frequently observed. The tumor showed mild to moderate and inhomogeneous enhancement by intravenous injection of contrast medium. A tendency to ipsilateral hemicerebral atrophy was found in one case. These findings were somewhat different from those of germinomas in the pineal and suprasellar regions. This phenomenon may be related to the anatomical difference of the brain where the tumor originated.     

Wilms tumor (nephroblastoma) in the adult patient: clinical and radiologic manifestations

Wilms tumor (nephroblastoma), a primary renal neoplasm containing primitive blastema and embryonic glomerulotubular structures, is seen rarely in adults. To identify clinical and radiologic criteria for preoperative diagnosis of adult Wilms tumor, we studied 29 cases reported in the literature from 1975 to 1987 (all patients were 15 years old or older) and four newly diagnosed cases. The mean age of patients was 30 years; 80% were less than 35 years old. Each patient presented with a large, rapidly growing, abdominal mass (average duration of symptoms, less than 2 months), had no constitutional symptoms (e.g., weight loss, fever), and otherwise were healthy (80%). Twenty-six patients had IV or retrograde pyelograms. Twenty-three showed a nonspecific mass effect. In seven (78%) of nine patients, abdominal CT scans showed a large, inhomogeneous mass with large areas of low density and increased enhancement of the compressed remaining normal renal parenchyma, which resembled a pseudocapsule. In five (63%) of eight patients, sonograms showed a complex mass with large cystic components. In 18 (82%) of 22 patients, arteriograms showed a hypovascular mass with fine wavy or zigzag (creeping-vine) neovascularity. We conclude that a rapidly growing renal mass in a young patient (less than 35 years old) that is shown to be complex and cystic by CT or sonography and that is hypovascular with fine, wavy neovascularity on arteriography is suggestive of adult Wilms tumor (75-80%). An awareness of this constellation of findings may be helpful in diagnosing this unusual tumor before surgery.     

Investigation of juxtasellar and cerebellopontine angle meningiomas and neurogenic tumours: two-phase helical CT

We performed two-phase helical CT in 31 patients with juxtasellar region and cerebellopontine angle tumours to evaluate its usefulness in differentiating meningiomas from neurogenic tumours. After the intravenous injection of 90 ml contrast medium at 3 ml/s, axial helical images were obtained with delays of 30 and 120 s. After the delayed axial images, we acquired coronal images. Changes in attenuation were assessed visually and quantitatively (by comparing the attenuation in Hounsfield units). There were 17 meningiomas and 14 neurogenic tumours, all pathologically proven. Two-phase helical CT showed a decrease in attenuation in 15 (88 %) meningiomas and an increase in 14 (100 %) neurogenic tumours from early to delayed axial images. Coronal images showed a decrease in attenuation in all 17 meningiomas and an increase in 13 (93 %) of the neurogenic tumours. The mean HU and their ratios were significantly different between meningiomas and neurogenic tumours. Received: 22 August 2000 Accepted: 13 October 2000     

颅内血管平滑肌瘤的影像表现(附2例讨论)

目的探讨颅内血管平滑肌瘤的CT及MRI表现。资料与方法结合文献回顾性分析2例经手术病理证实的位于颅内鞍旁的血管平滑肌瘤的CT及MRI表现。2例均行MRI平扫及增强,1例行MRI动态增强,1例行CT平扫。结果 2例均位于右侧鞍旁。例1行CT平扫示中颅窝鞍旁类圆形稍高密度肿块,密度均匀,周围未见水肿,MRI平扫T1WI呈低信号,扩散加权成像(DWI)呈低信号,T2WI呈不均高信号,内可见条状低信号。病灶周围见薄层环状水肿带,增强扫描肿块明显均匀强化,局部可见脑膜尾征;例2 MRI平扫示鞍旁卵圆形肿块,T1WI呈等信号,T2WI呈高信号,右三叉神经受压,增强扫描早期示病灶中心斑片状强化,增强晚期示病灶逐渐从中心向周边强化。结论动态增强扫描呈中心性渐进性强化可能为颅内血管平滑肌瘤特征性表现,有助于其诊断与鉴别诊断。     

320排动态容积CT全脑灌注成像在脑梗死缺血半暗带分期中的应用

目的 应用320排动态容积CT全脑灌注成像探讨脑梗死缺血半暗带分期的可行性.资料与方法 测量18例存在缺血半暗带脑梗死患者的梗死核心区、缺血半暗带区及其镜像对侧脑血容量(CBV)、脑血流量(CBF)、平均通过时间(MTT)及达峰时间(TTP),按脑梗死前期分期标准对缺血半暗带进行分期.结果 18例缺血半暗带区表现为MTT、TTP延长,CBF降低,CBV轻度升高、正常或轻度降低.与梗死核心区比较,缺血半暗带区CBV、CBF升高,MTT延长,TTP缩短(P＜0.05);与健侧对应区比较,CBF降低,MTT及TTP延长(P＜0.05),而CBV无显著差异(P＞0.05).缺血半暗带分期:Ⅰ2期3例,Ⅱ1期9例,Ⅱ2期6例.结论 应用320排动态容积CT全脑灌注成像可明确脑梗死患者的病变部位、范围以及有无缺血半暗带存在,并可对缺血半暗带进行分期.     

Computed tomography of intracranial chondroma with emphasis on delayed contrast enhancement

Intracranial chondroma is an unusual cartilaginous tumor originating from the base of the skull. We report on two cases of intracranial chondroma that showed delayed contrast enhancement on CT after high-dose administration of contrast medium. This CT feature may be useful to differentiate chondromas from other tumors of the skull base such as meningiomas and neurinomas.     

Stable xenon CT in patients with chronic cerebrovascular disease

Xenon-enhanced CT (XeCT) is a method of measuring regional cerebral blood flow (rCBF). Although it is used for acute and perioperative assessment the ability of XeCT to show hypoperfused areas in vivo, as compared with morphological imaging modalities other than noncontrast CT, is not defined. Correlation with MRI helps to define the smallest detectable hypoperfused area. We examined 17 patients 6 weeks after acute cerebral infarcts with CT, XeCT and MRI and the findings were compared. All examinations were performed with the same slice angulation and thickness and the sizes of the abnormal areas were measured. XeCT showed a high correlation with MRI, but less so with conventional CT Lesions appeared significantly smaller on CT than on XeCT or MRI. No significant difference between MRI and XeCT changes was found. The minimal lesion on MRI correlating with a hypoperfused area on XeCT was 0.8 cm², whereas lesions measuring less than 0.5 cm² on MRI could not be detected on XeCT. The good correlation between XeCT and MRI underlines the reliability of rCBF examinations with XeCT A significant difference between CT and XeCT findings shows the difficulty of interpreting hypoperfused regions only by correlation with CT. Combined XeCT and MRI gives a better estimate of the vascular state of the brain.     

联合MRI和CT诊断微小脑膜瘤

目的 探讨微小脑膜瘤CT和MRI早期敏感征象,提高其检出率.方法 回顾性分析41例经临床随访及病理确诊为微小脑膜瘤的临床及影像学资料,观察并记录微小脑膜瘤发生部位、CT密度、MRI信号特点,对结果进行统计学分析.结果 21例患者行CT平扫检查,其中5例呈钙化密度,12例呈高/稍高密度,4例呈等密度.41例患者均行MRI检查,T1 WI:37例呈等信号,4例呈低信号;T2 WI:33例呈等信号,4例呈高信号,4例呈低信号;FLAIR:14例呈略高信号,27例呈等信号.13例患者行扩散加权成像(DWI)检查,其中5例呈高/稍高信号.MR增强扫描病变均呈明显强化.结论 MR多序列(FLAIR、DWI)、多方位(矢状面)结合增强扫描、薄层扫描并联合CT平扫可极大地减少微小脑膜瘤的漏诊率.     

Relationship between extent of brain hypoperfused area and functional outcome in patients with a small subcortical infarction: evaluation with X-ray CT, 123I-IMP cerebral perfusion SPECT and cerebral angiography]

We performed 123I-IMP single photon emission computed tomography (SPECT) in 43 patients who had a small infarction (less than 2 cm) in subcortical area and who were less than 1 month after onset of stroke. Hypoperfused area of brain was qualitatively assessed and was compared with functional outcome at 6-month after the stroke and the cerebral angiogram. Functional outcome was poorer in patients who had wider hypoperfused area in brain (chi 2 = 29.3; p less than 0.001). The extent of brain hypoperfused area showed a positive correlation with the degree of stenosis in the extracranial and/or intracranial arteries (r = 0.61; p less than 0.01). In patients who had no angiographic abnormality, the extent and the location of the hypoperfused area were equivalent to that of the low density area in CT. Thus 123I-IMP SPECT in patients with a small infarction may discriminate lacunar infarction from embolic or hemodynamic infarction, which was caused by vascular lesions of major cerebral arteries, in subcortical area. Our study suggests that functional outcome is better in lacunar infarction than embolic or hemodynamic infarction in subcortical area.     

特殊部位的脑膜瘤CT、MRI影像表现

目的　探讨特殊部位脑膜瘤的影像特征。方法　回顾性分析 11例手术和病理证实的特殊部位 (侧脑室、鞍隔、额窦 )脑膜瘤的MRI、CT表现。其中MRI检查 8例 ,CT检查 3例。结果　 11例均为单发。位于侧脑室 4例 ,鞍隔 4例 ,额窦 3例。T1WI加权像上脑膜瘤信号主要为等信号和略低信号。T2 WI加权像上脑膜瘤信号主要为等信号、略高信号、略低信号。MR增强为均匀强化或不均匀强化。CT平扫 :表现为均匀等密度和稍高密度 ,均未做强化。病理分型 :纤维母细胞型 4例 ,血管母细胞型 3例 ,合体细胞型 1例 ,砂粒体型 3例。 11例脑膜瘤中有 9例误诊。结论　提高特殊部位脑膜瘤影像学诊断正确率 ,对临床确定正确手术入路、提高肿瘤手术治愈率有重要意义     

大脑中动脉高密度征的动态CT表现与临床

目的探讨大脑中动脉高密度征(HMCAS)在大脑中动脉(MCA)供血区超急性期梗死的诊断价值。方法对46例MCA供血区超急性期脑梗死(发病6h内)的CT征象及临床表现进行分析,并定期复查CT观察其动态变化。结果MCA供血区超急性期脑梗死46例中表现为HMCAS者32例(71.1%),临床均为完全前循环梗死(TACI),25例死亡(78.1%),其中HMCAS进展且合并MCA点状征的14例中12例(85.7%)死亡,其余均遗留严重神经功能缺损;而无HMCAS的14例中8例为部分前循环梗死(PACI),6例为TACI,仅2例(14.3%)死亡,两者差异具有统计学意义(P<0.01)。3例HMCAS在复查随访时消失,病人病情好转且均转化为出血性脑梗死。结论大脑中动脉高密度征的动态CT变化有助于MCA供血区超急性期脑梗死的诊断及预后判断。     

眶内脑膜瘤的CT诊断

目的探讨眶内脑膜瘤的CT表现,提高其CT诊断水平。方法回顾性分析1997-10—2006-10在我院经手术及病理检查确诊的眶内脑膜瘤(原发或继发)17例CT表现和临床资料。结果视神经鞘脑膜瘤11例,眶骨膜脑膜瘤4例,蝶骨嵴脑膜瘤2例。增强扫描,病变大多数呈均匀性强化。"车轨征"、"套袖征"及眶骨增生性改变是眶内脑膜瘤较为特征性的征象。结论CT检查对眶内脑膜瘤的诊断具有重要价值。     

Cerebral astrocytomas: histopathologic correlation of MR and CT contrast enhancement with stereotactic biopsy

Gadolinium-labeled diethylenetriaminepentaacetic acid was used as a contrast agent for stereotactic magnetic resonance (MR) imaging in six selected patients with brain tumors who underwent stereotactic biopsy. Regions of contrast enhancement demonstrated by computed tomography (CT) and MR imaging in four of the six patients correlated with areas of malignant neovascularity and endothelial proliferation within solid tumor. Radiation necrosis produced contrast enhancement indistinguishable from that of recurrent neoplasm. Isolated tumor cells within intact white matter were identified in biopsy specimens obtained outside of regions that were depicted as abnormal by contrast material-enhanced CT, as well as by precontrast and postcontrast T1- and T2-weighted MR images.     

周围型肺癌CT征象和动态CT增强与肿瘤微血管密度相关性研究

目的探讨周围型肺癌CT征象和动态CT增强表现与肿瘤微血管密度的关系。方法30例经手术病理证实为周围型肺癌,术前行螺旋CT平扫和动态增强扫描,并观察其征象并测量感兴趣区CT值。病理标本采用免疫组织化学染色SP法表达抗体CD34,并进行病理学观察。结果肿瘤微血管密度与周围型肺癌组织学类型无关(P>0.05),与肿瘤的分化程度、CT影像上肿瘤直径、分叶征、棘状突起、血管集束征、胸膜凹陷征、纵隔淋巴结转移均有密切相关(P<0.05),而与毛刺征无关(P>0.05);肺腺癌的强化幅度略高于鳞癌,但没有统计学意义(P>0.05),肺腺癌与鳞癌的强化幅度均与其MVD值呈正相关(r=0.619,P<0.05;r=0.586,P<0.05)。结论周围型肺癌CT征象和动态CT增强有助于对肺癌的血管密度和预后的评价。