颅内脂肪瘤的CT诊断（附4例报告及文献复习）

颅内脂肪瘤很少见,在CT问世以前很少在生前或术前作出诊断,CT对脂肪有很高的分辨力,可作出定性诊断。现报告4例。 一般资料 本组4例颅内脂肪瘤,男性3例,女性1例。年龄7～52岁,平均年龄31岁。3例为单发病变,1例多发(颅内2个病变),共5个病变。CT检查发现肿瘤位于胼胝体区2例,其中1例并有松果体池内脂肪瘤,向上突入右侧脑室内,1例位于环池左翼内,另1例病变位于三脑室上池内。病变形态位于胼胝体部者为长条形,其余为椭圆形。最小者直径不足1cm,最大者达4.3×0.86cm;CT值在一25Hu～一92Hu之间,1例作增强扫描,病变未见强化。     

眼球表面结膜皮样瘤及皮脂肪瘤的CT分析

目的　探讨眼球表面结膜皮样瘤及皮脂肪瘤的临床、病理及CT特征,评价CT检查的价值。方法　回顾性分析手术病理证实的眼球表面结膜皮样瘤及皮脂肪瘤12例,其中皮样瘤5例,皮脂肪瘤7例。女性多于男性(11∶1),均为单眼单个病灶,右眼多于左眼(9∶3)。术前均行常规眼眶CT横断面扫描,其中5例行增强扫描,分析其临床、病理及CT特征。结果　CT上病灶均表现为附着于眼环颞侧的新月形低密度影,最大25mm×15mm,最小8mm×5mm,外缘结膜下均有1~3mm厚的囊壁,增强后囊壁中度强化。皮样瘤较小,壁较厚,CT值-55~-75HU。皮脂肪瘤较大,壁较薄,CT值-80~-120HU。结论　CT检查可明确病灶的大小、范围、性质,以及与眼环、外直肌、泪腺等的关系,有助于提高手术成功率,减少并发症。     

低剂量螺旋CT肺部扫描对肺密度的评价

目的　探讨螺旋CT扫描剂量、层厚是否对肺密度有影响 ,以决定常规剂量螺旋CT扫描测得的肺密度值能否适用于低剂量螺旋CT。资料与方法　对 2 0名志愿者进行胸部螺旋CT扫描 ,采用 5种不同参数重复扫描 :低剂量 (5 0mA) ,层厚 8mm、5mm、3mm ;常规剂量 (2 0 0mA) ,层厚 5mm、3mm。分别在主动脉弓、气管隆突、下肺静脉干平面测量肺密度 (HU) ,计算不同剂量、层厚平均肺密度并进行统计学分析。结果　低剂量CT扫描 3种层厚中 8mm的肺密度值为 - 793± 4 5HU ,5mm为 - 80 0± 4 6HU ,3mm为 - 80 2± 5 1HU ,三者无统计学差异 (P >0 .0 5 ) ;层厚 5mm的肺密度值 ,低剂量为 - 80 0± 4 6HU ,常规剂量为 - 80 1± 37HU ,两者无统计学差异 (P >0 .0 5 ) ;层厚 3mm的肺密度值 ,低剂量为 - 80 2± 5 1HU ,常规剂量为 - 80 5± 4 9HU ,两者无统计学差异 (P >0 .0 5 )。结论　扫描剂量和层厚对肺密度没有显著影响 ,低剂量螺旋CT值可以参考常规剂量扫描测得的肺密度值来判断有无肺气肿等异常。     

低剂量螺旋CT肺结节扫描与常规剂量CT的对照研究

目的　通过对肺结节模型进行低剂量和常规剂量CT扫描 ,评价低剂量CT对肺内结节的检出率 ,分析影响低剂量CT肺结节检出率的因素。方法　用包绕水囊的绷带卷模拟肺及胸廓 ,面粉、黄油及固体石蜡按一定比例制作成CT值 - 10～ 5 0HU的结节 ,直径为 10和 5mm。分别进行常规剂量 (2 4 0mA、14 0kV)及 3组低剂量扫描 (4 3mA、14 0kV ;5 0mA、12 0kV ;75mA、80kV)扫描 ,低剂量各组分别以螺距 1 0、1 5、2 0扫描。比较不同剂量、不同螺距组之间的差别。将不同X线剂量模型CT扫描图像与正常成人胸部图像融合 ,由 3名医师在不知模型结节的情况下分别读片 ,统计肺内结节的检出率和假阳性、假阴性率。分析扫描剂量、螺距对其检出率的影响。结果　低剂量扫描对肺内 10mm及 5mm结节的检出率分别为 10 0 %、89 7% ,与常规剂量组之间的差异无显著性意义(χ2 =0 6 90 7,P >0 70 )。增加螺距导致 5mm的结节检出率下降。结论　低剂量CT对肺内直径 10mm和 5mm结节的检出率与常规剂量CT无差别。增大螺距导致肺内结节的密度及边缘的清晰度下降 ,结节检出率也相应下降。     

薄层CT扫描对小叶间裂的临床应用价值

目的：探讨薄层CT扫描对小叶间裂的临床应用价值。方法：本文通过对30例患者进行扫描比较，设备采用日立PRATICO螺旋CT扫描仪，常规CT扫描自肺尖至肺底，采用10mm层厚，层间距10mm；常规CT扫描后，在右肺中间段支气管水平加扫薄层CT，6-8层，采用1、2、3、5mm层厚，层间距≤3mm，所有扫描照相条件肺窗为窗宽1000HU，窗位-550HU。结果：30例患者经常规CT扫描(层厚10mm)显示小叶间裂之形态、宽度与薄层(1、2、3、5mm)扫描比较有显著差异。常规扫描肺窗图象中，小叶间裂显示三角形、片状少血管区占80％，余20％显示不清；而薄层CT显示为弧带状(59％)、C形(32％)或线状(9％)较清晰之稍高或高密度影，未发现一例呈低密度少血管区。结论：薄层CT扫描对了解小叶间裂的正常解剖形态及变异，以及微小病灶在右肺叶的准确定位有重要价值。     

外伤性急性硬膜下血肿CT征象及其临床预后关系（附16例报告）

目的 研究急性硬膜下血肿CT表现与临床预后关系。材料和方法16例病人均为受伤后8h内行CT检查确诊，其中男12例，女4例，年龄10-16岁之间，均为交通事故受伤。采用东芝Asteion（Tsx-021B）型螺旋全身CT扫描机做轴位扫描，时间1s，层厚10mm，层距10mm。     

螺旋CT高分辨力扫描对支气管扩张症的临床诊断价值

1．材料和方法 收集自1992年6月-2003年5月，经螺旋CT高分辨力扫描证实的支气管扩张患者65例，男40例，女25例，年龄24岁-71岁，平均年龄47．5岁。临床表现均有咯血病史，临床医生高度怀疑支气管扩张，病程3月-4年不等。使用设备为ELSCENT HELICAT FLASH螺旋CT扫描机，常规扫描层厚8．8mm，层距8．0mm，螺距     

眼眶CT扫描技术的运用

眼眶内的肌肉、神经、血管的密度(30—50Hu)和球后脂肪的密度(-80—-100Nu)有较大的反差,对于眼眶的病变,CT检查尤为合适。它已经取代了眼眶的球后充气或注射碘剂的X光造影,很大程度上减少了眼眶的动脉或静脉造影。 我院从1985年7月—1990年5月做眼眶CT扫描42人次,其中男31人,女11人,年龄3—79岁。扫描机为美国Picker公司1200SX型。病人取仰卧位,头稍后伸,闭眼,基线为Reid’s线,个别为与Reid’s线成-30°基线,层厚3mm、5mm、10mm,层距4mm,5mm、10mm,曝光时间4秒、少数病人做了冠状扫描。CT表现:球后占位病变11例,甲亢突眼、眼外肌肥厚6例,眼球病变4例,眼外伤3例。     

多层螺旋CT常规头部扫描最佳方案的探讨

头部CT扫描是日常工作中广泛应用的检查项目,找出多层螺旋CT最佳的头部扫描方法有很大的实用价值,可以减少重复扫描,减轻患者的经济负担,降低群体受照剂量,增加医院的工作效益。1材料和方法我们所用的设备是LightSpeedPlus多层螺旋CT机(8层16排等宽探测器)。扫描层厚7.5mm,床速12.5mm,扫描类型360°螺旋1s,120kv,250mA,后处理工作站Aw4.05。扫描基线为上眶耳线。扫描范围为顶骨至上颌窦层面。标准算法:志愿者10名(口头协议),A组:直接轴向扫描10例,层厚7.5mm,5mm和2.5mm,120kv,250mA。B组:厚层螺旋扫描,行回顾性薄层重建。2结果7.5mm层…     

脑膜瘤的螺旋CT诊断

材料和方法选取经手术和病理证实的脑膜瘤14例，女8例，男6例，年龄20-57岁，平均40岁，其中10例做了增强扫描，扫描设备为GE Hispeed FX／i全身CT扫描机，层厚层距均为10mm，必要时加扫薄层及增强扫描。     

Preface

Intracranial lipomas are rare congenital malformations. They are usually pericallosal asymptomatic midline lesions. Other brain malformations are often seen in association with intracranial lipomas. We describe the findings of imaging studies, including computed tomography (CT), magnetic resonance (MR) imaging, and MR angiography, along with a brief review of the literature. The frequency and the spectrum of the associated brain malformations are also discussed. We retrospectively reviewed CT and MR findings of 24 patients (14 female, 10 male, mean age 38.6 years) diagnosed with intracranial lipoma between December 2000 and June 2004 in two different radiology departments. Seventeen of the patients were diagnosed using cranial MR and seven with cranial CT. The CT density of all lesions was measured. Imaging characteristics of lipomas, morphological findings and associated malformations were described. The intracranial locations of the lipomas were left-sided quadrigeminal cistern (n=3), right-sided quadrigeminal cistern (n=4), interpeduncular cistern (n=1), sylvian fissure (n=3), interhemispheric fissure (n=3), choroid plexus (n=2), intercerebellar fissure (n=3), corpus fornicis (n=1) and the periphery of the corpus callosum (n=4). Eighteen of the intracranial lipomas were tubulonodular; six were curvilinear. Associated anomalies were observed in six patients. All of the patients with sylvian fissure lipoma had seizures. The two preferential sites of intracranial lipomas were pericallosal and dorsal mesencephalic. Most intracranial lipomas are found incidentally during neuroradiological investigations. CT and MR examination usually lead to the diagnosis, because of the very low attenuation values of lipomas on CT and the short T1 and T2 on MR. Midline anomalies and other malformations such as aneurysms are frequently associated with intracranial lipomas. Careful radiologic evaluation is therefore necessary to evaluate associated pathologies. Sylvian fissure lipomas should be considered in the differential diagnosis of patients with epilepsy.     

胼胝体脂肪瘤的CT和MRI诊断

目的　研究胼胝体脂肪瘤的CT和MRI征象及诊断价值。方法　 1 8例胼胝体脂肪瘤 ,男 1 0例 ,女 8例 ,年龄 2个月～ 55岁。均行头颅CT和MRI平扫 ,同时行MRI脂肪抑制成像。结果　 1 4例单发 (77.8% ) ,4例多发 (2 2 .2 % )。曲线型 1 4例(77.8% ) ,管结节型 4例 (2 2 .2 % )。CT表现为低密度区 (CT值 - 4 4～ - 71HU) ,MRI表现为短T1 、中长T2 和高质子密度信号 ,在各序列上均与脂肪组织信号同步。 1 2例 (66 .7% )合并颅内外的单或多部位发育异常 ,包括胼胝体发育不良或缺如 ,透明隔缺如 6例 ,颅内其他部位多发脂肪瘤 4例 ,灰质异位 2例 ,脑裂畸形、巨脑回、蛛网膜囊肿、额顶皮下脂肪瘤及局部颅骨缺损各 1例。结论　胼胝体脂肪瘤在CT和MRI上有特征性表现。本病常合并颅内外的各种先天性发育异常。MRI检出本病优于CT。CT与MRI结合可在活体上做出诊断     

Frontal subcutaneous lipoma associated with large interhemispheric lipoma and corpus callosum agenesis

Intracranial lipomas are extremely rare fat-containing lesions that comprise 0.1%-0.5% of all primary brain tumors. They are congenital lesions that arise due to persistence and maldifferentiation of the meninx primitive (subarachnoid space precursor). We report a case of a 30-year-old woman who presented with seizures due to an intracranial lipoma and no neurological deficits. CT (computerized tomography) imaging findings demonstrated a large interhemispheric partially calcified lipoma that communicated with a large scalp lipoma and was associated with agenesis of the corpus callosum. Compared to the prior CT imaging, the lipoma increased in size from 3.4 cm to 4.1 cm transversely. A recent CT angiogram done due to suspicion of an aneurysm showed the lipoma now measuring 6 cm by 4.7 cm. Most cases of intracranial lipoma have been reported in the pediatric age group. Here, we report a rare case of interhemispheric intracranial lipoma in the adult age group. This case also demonstrates the importance of imaging modalities for detecting intracranial lipoma without performing invasive brain biopsy.     

CT and MR imaging characteristics of intravestibular lipoma

BACKGROUND AND PURPOSE: Intracranial lipomas are uncommon congenital malformations that most often are asymptomatic. A rare subset of intracranial lipomas arises within the vestibule of the inner ear, which can cause sensorineural hearing loss. We present the CT and MR imaging characteristics of lipomas within the vestibule of the inner ear and propose a pathogenetic mechanism for this malformation. METHODS: We retrospectively reviewed five cases of vestibular lipoma. T1-weighted axial conventional spin-echo and T2-weighted axial fast spin-echo sequences were performed in all five cases. Four patients underwent T1-weighted fat-saturated imaging, and one underwent CT scanning with Hounsfield units measured. RESULTS: Four female patients ranging in age from 10 to 40 years and one 26-year-old male patient had sensorineural hearing loss. Two patients had progressive high-frequency loss; one, sudden-onset high-frequency loss; and two, congenital high-frequency loss. All had lesions within the vestibule that displayed hyperintensity on T1-weighted images, isointensity to slight hypointensity on T2-weighted fast spin-echo images, hypointensity with fat saturation, and fat attenuation on CT scans. Three of the cases were associated with lipoma of the cerebellopontine angle. In none of these cases were the cerebellopontine angle and labyrinthine lipomas contiguous. CONCLUSION: Intravestibular lipoma is considered when a focal hyperintense lesion is identified within the vestibule of the inner ear on T1-weighted MR images. Lesion hypointensity on fat-saturated T1-weighted MR images verifies its lipomatous nature and separates it from intralabyrinthine hemorrhage or highly proteinaceous fluid.     

骨脂肪瘤的影像学表现及其诊断价值

目的探讨骨脂肪瘤的影像学表现及其诊断价值.方法结合文献复习,回顾性阅读病理证实的10例骨脂肪瘤的X线平片和CT片,分析其征象.结果骨内脂肪瘤8例,分别位于股骨颈1例、股骨颈-转子间区1例、髋臼4例、跟骨2例,X线平片表现为边界清或不清的不规则形透亮区,其内可见斑块状钙质样密度影,边缘可伴硬化.CT表现为类圆形或不规则形脂肪密度区,CT值为-22～-120 HU,伴有厚薄不均的硬化边,其中6例病灶中央和（或）边缘可见小结节状钙化.骨旁脂肪瘤2例,分别位于股骨旁和髂骨旁,表现为骨旁边缘清楚的脂肪性肿块,呈半圆形凸向邻近软组织内,邻近骨皮质增生肥厚或伴伸向肿块的骨性突起或树枝状骨性结构.结论骨脂肪瘤以主要含有脂肪成分为共同特点,但不同部位骨脂肪瘤的影像学表现有所不同,CT能对其作出正确的术前诊断.     

心脏脂肪瘤的CT诊断

目的 探讨CT在心脏脂肪瘤诊断中的价值.方法 对经CT检查并手术病理证实的6例心脏脂肪瘤患者进行分析.4例行电子束CT单层平扫、增强扫描与电影横断增强扫描,2例行64层CT平扫与增强扫描.结果 (1)CT诊断右心房心腔内型孤立性脂肪瘤1例,心包内型孤立性脂肪瘤1例,壁在型脂肪瘤4例.其中壁在型2例为起自左心室或右心室及室间隔的浸润性脂肪瘤,2例为起自房室间隔的孤立性脂肪瘤.(2)CT成像与三维重组不但清晰显示肿瘤的位置、形态、大小、边缘和特征性的脂肪密度,提示肿瘤的诊断与分型,而且对并存的冠状动脉受推移位、肺部感染、心包和胸腔积液等异常均可同时显示.结论 CT检查对心脏脂肪瘤的诊断和分型具有很高准确性,具有良好应用价值.     

蛛网膜下腔出血的CT诊断(附200例分析)

目的：探讨蛛网膜下腔出血（SAH）的病因及CT表现,方法：选择经腰穿或CT复查证实为SAH的病例200例,结合部位及其它检查分析其病因及CT表现,结果：外伤性98例,其中单纯性20例,合并其他颅内损伤78例,自发性80例,血管畸形所致20例,由动脉瘤所致15例,其它45例,新生儿缺血缺氧性脑病22例,CT表现为纵裂池出血80例（表现为纵裂高密度影增宽75例,纵裂高密度影延长32例,侧脑室体部上10mm层面内出现条状高密度影15例,天幕切迹变厚,天幕区密度增高30例）;其它脑池偏密征102例,脑沟密度增高85例,结论：脑池肮脏了沟密度增高为SAH的CT表现,CT检查为SAH的诊断快捷,准确,且无痛苦,无危险。     

Pathogenesis of intracranial lipoma: an MR study in 42 patients

Intracranial lipomas are uncommon lesions whose development remains poorly understood. To clarify the anatomic and embryologic features of intracranial lipomas, we retrospectively reviewed the MR scans of 42 patients with 44 intracranial lipomas. Interhemispheric lipomas were the most common, accounting for 45% of cases. The remainder of the lesions were clustered in the quadrigeminal/superior cerebellar (25%), suprasellar/interpeduncular (14%), cerebellopontine angle (9%), and sylvian (5%) cisterns. Fifty-five percent of the lesions were associated with brain malformations of varying degrees. Intracranial vessels and nerves were noted to course through 16 (36%) of the lesions. The relative frequencies of the locations of the lipomas correspond to the temporal sequence of dissolution of the meninx primitiva, the mesenchymal anlage of the meninges. This finding supports the concept of lipoma formation as a result of abnormal persistence and maldifferentiation of the meninx. This embryologic concept of the development of intracranial lipomas explains the high frequency of callosal and other brain hypoplasias. Intracranial lipomas are neither hamartomas nor true neoplasms; rather, they are congenital malformations.     

鼻咽癌颅内侵犯的CT诊断（附40例分析）

目的探讨鼻咽癌颅内侵犯的CT表现特点。方法搜集经病理确诊为鼻咽癌并伴有颅内占位的CT资料40例。采用SOMATOMPLUS全身CT扫描机行鼻咽部及颅脑检查,38例行轴位扫描,层厚层距均为5mm,2例冠扫,层厚层距均为3mm,其中13例进行了增强扫描。结果（1）鼻咽癌原发病灶40例;（2）中颅窝病变海绵窦不对称,患侧增宽36例;蝶鞍破坏11例;颞极占位5例;（3）后颅窝病变桥脑小脑角区占位病变10例;（4）前颅窝病变1例;（5）颅底骨质破坏33例,其中以破裂孔及卵圆孔破坏、吸收扩大最常见,分别为30例和23例。结论CT可精确显示鼻咽癌颅内侵犯的部位、途径及范围,有助于临床分期及指导放疗野的设置。     

Anterior interhemispheric calcified lipoma together with subcutaneous lipoma and agenesis of corpus callosum: a rare manifestation of midline craniofacial dysraphism

Frontonasal dysplasia (FND) or craniofacial dysraphism includes a variety of craniofacial defects. FNDs are rarely associated with intracranial lipoma. The majority of intracranial lipomas are incidentally identified on radiological examinations. They are commonly accompanied by other congenital intracranial malformations. Moreover, they are rarely associated with subcutaneous lipoma. We present a rare case of midline craniofacial dysraphism with interhemispheric calcified lipoma together with subcutaneous lipoma and agenesis of the corpus callosum.