颅骨转移性病变的MRI诊断

目的：探讨MRI对颅骨转移性病变的诊断及临床价值,分析各MRI序列的诊断价值。方法：回顾性分析17例经病理证实的颅骨转移性病变的病例资料,其中原发肿瘤为肺癌11例,白血病2例,前列腺癌2例,乳腺癌1例,直肠癌1例。17例均行MRI检查,其中平扫5例,直接增强4例,同时行平扫及增强8例,其中5例行ECT骨扫描,9例行CT平扫。MRI的主要序列有矢状面和轴面T1WI、T2WI及增强扫描。结果：17例中单发颅骨转移3例,多发颅骨转移14例,本组转移病灶的好发部位依次为颞骨、顶骨、枕骨、额骨等,合并颅内脑实质转移15例。9例兼行MR和CT的患者中,在MRI上2例发现了更多的颅骨病灶,3例检出了颅内病灶;5例兼行MR和ECT的患者中,所有颅骨及颅内的病灶的细节在MR上显示更清晰。颅骨转移的MRI主要表现为局灶性溶骨性病灶呈长T1、长T2信号或成骨性病灶呈长T1、短T2信号,13例平扫MR中,10例在T1WI上的信号均较T2WI上明显;病灶可侵及颅骨内外板以及脑膜,呈新月状或双凸形影,12例行增强扫描病例均强化明显。结论：MRI对颅骨转移的具有极高的诊断价值,可发现细微的病灶,T1WI和增强扫描是有价值的扫描序列。     

颅盖骨朗格汉斯组织细胞增生症的CT和MRI表现

目的:探讨颅盖骨朗格汉斯组织细胞增生症的CT及MRI特征.方法;回顾性分析12例经病理证实的颅盖骨朗格汉斯组织细胞增生症的CT及MRI表现.结果:主要CT表现为肿瘤起源于颅骨板障并侵犯颅骨内外板,可见边界清楚的“梯形”骨质破坏区,病灶呈“葫芦状”软组织密度影,6例密度不均匀,其中3例残留小骨片、1例残留脂质.MRTtWI上肿瘤呈低-等信号,T2WI上呈混杂高信号,DWI上5例呈高信号、1例呈略低信号,增强扫描呈中度强化.7例病变侵犯硬脑膜.结论:颅盖骨朗格汉斯组织细胞增生症的影像学表现有一定特征性,综合运用CT与MRI检查能提高术前诊断准确性.     

颅骨表皮样囊肿的影像学表现及文献回顾

目的 探讨颅骨表皮样囊肿CT及MRI表现特点.方法 回顾性分析7例经手术证实的颅骨表皮样囊肿的CT及MRI表现,3例行CT及MRI平扫,其中2例行MRI增强扫描,4例只行CT扫描.结果 病变发生于枕骨4例,顶骨2例,颞骨1例.7例CT表现为颅骨膨胀性骨质破坏,类圆形或分叶状,边缘锐利,周围见断续钙化边或硬化带,病变中心呈混杂密度,3例病灶内可见死骨样高密度影.MRI表现为T1WI混杂低信号,T2WI混杂高信号,脂肪抑制序列呈高信号,增强扫描病变较小者无明显强化,病变较大者周围见淡薄线样强化,囊内容物无强化.当囊内容物中以蛋白、胆固醇结晶为主、轻微钙化时,CT表现为混杂密度,其内可出现高密度影,对应的MR T1WI呈等或高信号,T2WI为低或等信号.手术显示病变相邻脑实质均未受累.结论 CT与MRI结合对术前诊断颅骨表皮样囊肿很有价值.     

颅骨骨巨细胞瘤的影像诊断

目的 探讨颅骨骨巨细胞瘤(GCT)的CT、MRI征象, 提高对本病的认识.方法 回顾性分析经手术病理证实的5例颅骨GCT的CT、MRI表现, 5例患者均行普通CT平扫,2例行CT增强扫描;3例以颞骨破坏为主的病例,均行颞骨MRI平扫、增强扫描及HRCT扫描及听骨链、面神经计算机重建.结果 5例均单侧发病, 右侧4例、 左侧1例.CT平扫显示广泛的膨胀性骨质破坏、残存骨嵴及骨包壳.肿瘤信号多变,在T1WI呈低-等信号;在T2WI肿瘤呈不均匀的高信号,病灶周边T2WI呈现特征性的低信号,增强扫描:实性部分表现为不均匀强化.结论 颅骨GCT的CT平扫显示广泛的膨胀性骨质破坏不伴硬化边、残存骨嵴及骨包壳,T2WI病灶周边低信号是本病的特征性影像学表现;颞骨HRCT扫描及听骨链、面神经CPR重建为术前评估听小骨、面神经受累情况,为临床制定治疗策略提供更准确的影像信息.     

颅骨少见良性病变的影像诊断分析

【摘要】 目的：探讨CT及MRI对颅骨良性病变的诊断价值。方法：回顾性分析13例以骨质破坏为主的颅骨良性病变的CT及MRI表现,并与其病理表现进行对照分析。结果:13例中骨纤维结构不良6例,主要CT表现为局限性小病灶（5例）多呈磨玻璃密度,弥漫性病灶（1例）可见磨玻璃密度及丝瓜络样改变;主要MRI表现为病灶在T1WI及T2WI上均以低信号为主;骨化性纤维瘤3例,主要CT表现为肿瘤呈膨胀性生长,骨皮质破坏不明显,无骨膜反应;巨细胞修复性肉芽肿2例,主要CT表现为病灶内可见多发骨性分隔,MRI上可见病灶呈多房样改变;胆固醇性肉芽肿1例,在T1WI、T2WI及压脂图像上病灶均呈高信号,有一定特征性;动脉瘤样骨囊肿1例,其特征性影像表现为病灶内可见液 液平面。结论：部分颅骨良性病变具有特征性的影像学表现,CT及MRI检查有助于这类病变的诊断及鉴别诊断。     

颅骨嗜酸性肉芽肿的X线、CT、MRI诊断

目的:探讨颅骨嗜酸性肉芽肿的影像表现及鉴别诊断.材料和方法:回顾性分析26例经病理证实的颅骨嗜酸性肉芽肿的X线、CT、MRI表现.结果:26例共发现29个病灶.其中单发24例(额骨12例、顶骨8例、颞骨3例、枕骨1例),多发2例.主要表现为起源于颅骨板障并侵犯内外板、边界清楚的骨破坏,病灶内残留的小骨片(钮扣骨)、脂质和软组织肿块.CT呈不均匀密度,MRI呈稍长T1和稍长T2信号.结论:X线平片是诊断基础,结合CT、MRI能够提高诊断与鉴别诊断水平.     

儿童睾丸内胚窦瘤的CT和MRI特征分析

目的探讨儿童睾丸内胚窦瘤的CT及MRI特征,提高诊断的准确率。方法回顾性分析经手术病理证实的20例儿童睾丸内胚窦瘤的CT和MRI资料。其中行CT检查4例,3例行增强检查;行MRI检查16例,11例行增强检查。结果 20例病灶均单发,左侧睾丸12例,右侧睾丸8例,呈圆形或类圆形,边界清晰17例,模糊3例。CT平扫病灶均呈混杂密度包块,MRI平扫病灶T1WI呈等、等低或混杂信号;T12WI呈等、等高或稍高信号,CT及MRI增强扫描肿瘤实质部分不均匀强化明显。结论儿童睾丸内胚窦瘤的CT和MRI表现特殊,综合分析有助于提高术前诊断准确率。     

CT、MRI与DSA在脑内型海绵状血管瘤诊断中的价值

目的探讨CT、MRI与DSA检查在脑内型海绵状血管瘤诊断中的价值。资料与方法回顾性分析经手术病理证实的22例脑内型海绵状血管瘤患者资料,CT平扫22例,其中增强扫描17例。MRI检查22例,其中增强扫描13例。DSA检查5例。结果CT表现为高密度,略高密度,等密度。MRI表现为T1WI呈等或略低信号、T2WI呈高信号;T1WI与T2WI均呈高信号,病灶周围可见低信号环;T1WI与T2WI均呈低信号。病灶无占位效应或占位效应轻微,病灶多为不强化及轻微强化。DSA检查无肿瘤染色。结论脑内型海绵状血管瘤MRI表现典型,比CT表现更具特异性,与CT检查结合是诊断脑内型海绵状血管瘤的有效方法,参考DSA表现有利于脑内型海绵状血管瘤的诊断。     

腹部侵袭性纤维瘤病的CT及MRI特征

目的：探讨腹内侵袭性纤维瘤病的CT及MRI特征。方法：回顾性分析18例经手术病理证实的腹内侵袭性纤维瘤病CT及MRI表现。术前仅行CT检查9例,仅行MRI检查3例,同时行CT及MRI检查6例。结果：18例腹内侵袭性纤维瘤病表现为腹膜后或腹腔内软组织肿块。腹膜后肿块以浸润性生长呈不规则形、爪形多见;腹腔内肿块以膨胀性生长呈圆形、类圆形多见。CT检查15例中,平扫病灶呈稍低密度11例,等密度4例,病灶内未见坏死、钙化及脂肪密度,增强扫描动脉期病灶大部分呈不均匀轻度强化,静脉期病灶持续强化,延迟期强化最明显,其中9例病灶周边及内部残留有斑片状、条状无强化稍低密度区。MRI检查9例中,T2WI病灶均呈稍高信号;T1WI呈等信号5例,呈稍低信号4例;脂肪抑制T2WI序列,病灶呈明显高信号。其中6例病灶在各序列中均见有条带状致密胶原纤维形成的低信号影。动态增强扫描动脉期及静脉期病灶轻中度不均匀强化,延迟期病灶明显强化。结论：腹内侵袭性纤维瘤病的CT及MRI表现具有一定特征性,CT、MRI检查对该病有较高的诊断价值。     

脑裂头蚴病的CT和MRI诊断

目的:探讨脑裂头蚴病的CT和MRI表现。方法:回顾性分析5例脑裂头蚴病患者的CT和MRI表现,其中5例行MRI检查,3例同时行CT检查。结果:CT和MRI均能发现脑裂头蚴痛患者脑内多发病灶。主要CT表现为脑内多发不规则斑片状低密度影,边界模糊;可见散在宽点状钙化2例,局部脑萎缩2例;增强后病灶呈环状、结节状强化。MRI显示病灶多位于白质区,于T_1WI呈低信号,T_2WI呈高信号,边界模糊,占位效应不明显,增强后呈结节状、环状、串状或扭曲索条状强化,以矢状面或冠状面图像上显示最佳;出现脑萎缩3例;对CT所见钙化显示不佳。结论:CT和MRI能检出脑裂头蚴病患者的脑内多发病灶,并具有一定特征性表现。     

40例儿童郎罕细胞组织细胞病骨骼病变的影像学诊断

目的 :探讨儿童郎罕细胞组织细胞病 (LCH)骨骼病变的影像学表现及其诊断价值。材料和方法 :回顾性分析经病理证实的儿童LCH 40例 ,均行X线平片检查 ,其中 8例CT扫描。 14例分别于 1个月～ 2年内随访。结果 :本组中颅骨破坏 32例 ,占 80 %;脊柱破坏 9例 ,占 2 2 .5 %;长骨破坏 13例 ,占 32 .5 %;扁骨及不规则骨破坏 4例 ,占 10 %。嗜酸性肉芽肿以颅骨、长骨和脊柱多发 ,其他类型以颅骨多发。结论 :LCH骨骼病变具有多发性、多样性和多变性的特点 ;X线平片是本症诊断的基本手段 ,CT对隐蔽部位病变及病变细微结构的显示优于平片。     

颅骨嗜酸性肉芽肿的CT和MRI诊断

目的探讨颅骨嗜酸性肉芽肿的CT和MRI表现，提高对其诊断和鉴别诊断水平。资料与方法回顾性分析21例经手术病理证实的颅骨嗜酸性肉芽肿的CT和MRI表现，17例行CT平扫，12例行MR检查，10例行MR增强扫描。结果21例共发现24个病灶，其中单发19例（眼眶2例，斜坡2例，额骨9例，颞骨1例，顶骨4例，枕骨1例），多发2例。CT像上主要表现为颅骨板障的破坏，边界清楚，部分病灶内可见残留的小骨片以及大小不等的软组织肿块，密度不均匀。MR表现为T1低信号，T2高信号，CT和MRI增强扫描明显强化。结论颅骨嗜酸性肉芽肿的CT和MRI表现有一定的特征，CT和MRI有助于明确颅骨嗜酸性肉芽肿的诊断。     

儿童郎格尔汉斯细胞增生症的CT表现（附13例分析 ）

目的 探讨CT对郎格尔汉斯细胞组织细胞增生症（Langerhans cell histocytosis,LCH)造成多脏器损害诊断的价值及限度。方法 分析13例经临床、实验室、病理检查确诊的LCH的CT表现。局限性LCH4例,广泛性LCH9例。全部病例均行颅脑、胸部、肝、脾CT平扫检查,4例行增强检查。结果 男性多于女性,颅穹隆骨破坏依次为颞骨8例、顶骨3例、枕骨2例、额骨1例。CT发现早期骨破坏敏感性高。肿块变化可反映病变由活跃增殖到静止消退的病理过程。下丘脑－垂体轴侵犯影像表现晚于临床。CT可显著LCH不同阶段的肺损害。结论 LCH各脏器损害的影像学表现缺乏特异性。好发部位的典型CT表现可提示诊断,同时对辅助LCH分型、确定治疗方案、估计预后有一定价值。     

儿童郎格尔汉斯细胞组织细胞增生症的CT表现(附13例分析)

目的　探讨CT对郎格尔汉斯细胞组织细胞增生症(Langerhans cell histiocytosis,LCH)造成多脏器损害诊断的价值及限度。方法　分析13例经临床、实验室、病理检查确诊的LCH的CT表现。局限性LCH 4例,广泛性LCH 9例。全部病例均行颅脑、胸部、肝、脾CT平扫检查,4例行增强检查。结果　男性多于女性,颅穹隆骨破坏依次为颞骨8例、顶骨3例、枕骨2例、额骨1例。CT发现早期骨破坏敏感性高。肿块变化可反映病变由活跃增殖到静止消退的病理过程。下丘脑-垂体轴侵犯影像表现晚于临床。CT可显示LCH不同阶段的肺损害。结论　LCH各脏器损害的影像学表现缺乏特异性。好发部位的典型CT表现可提示诊断,同时对辅助LCH分型、确定治疗方案、估计预后有一定价值。     

Magnetic resonance imaging of thickened pituitary stalk proceeding to Langerhans cell histiocytosis in a child

Magnetic resonance imaging has shown isolated pituitary stalk thickening in certain cases of idiopathic or secondary central diabetes insipidus (DI) due to infiltrative processes. We present a 4-year-old boy who was initially diagnosed as having central DI. The MRI showed isolated pituitary stalk thickening with prominent homogeneous contrast enhancement. The remaining findings on MRI were within normal limits. The patient's personal and family history and laboratory and clinical findings were unremarkable; therefore, he was initially diagnosed as having idiopathic DI. Since central DI and isolated pituitary stalk thickening may be considered to be the first manifestations of Langerhans cell histiocytosis, we decided to follow up the patient. After 5 months, following the initial diagnosis, on skeletal X-ray survey, the patient did indeed develop multiple lytic skull lesions which, on biopsy, were histologically typical bone lesions of Langerhans cell histiocytosis.     

Differentiating Pediatric Rhabdomyosarcoma and Langerhans Cell Histiocytosis of the Temporal Bone by Imaging Appearance

BACKGROUND AND PURPOSE:Rhabdomyosarcoma and Langerhans cell histiocytosis are malignant lesions that can affect the skull base with similar radiographic characteristics on CT and MR imaging. We hypothesized that location within the temporal bone determined radiographically can provide useful adjunctive information in differentiating these distinct neoplasms.MATERIALS AND METHODS:We identified patients with Langerhans cell histiocytosis and rhabdomyosarcoma by using an imaging data base and International Classification of Diseases, Ninth Revision codes at a tertiary care academic medical center. Cross-sectional images were reviewed by a neurotologist and neuroradiologist, who evaluated the location of the lesions and scored each subsite—middle ear, mastoid, petrous apex, retrosigmoid/posterior fossa—on a scale of 0 (no involvement), 1 (partial), or 2 (complete involvement).RESULTS:We identified 12 patients representing 14 cases of Langerhans cell histiocytosis, and 9 patients representing 9 cases of rhabdomyosarcoma. For patients with Langerhans cell histiocytosis, mastoid involvement was rated 23/28 (82%) compared with 6/18 (33%) with rhabdomyosarcoma (P = .001). Langerhans cell histiocytosis was present in only the anterior portion of the temporal bone (petrous apex and middle ear) in 1 case (7.1%) and in the anterior portion of the temporal bone only in 5/9 (55%) cases of rhabdomyosarcoma (P = .018). The cortical bone was more commonly involved in Langerhans cell histiocytosis, 11/28 (39%) of cases compared with 2/18 (11%) cases in rhabdomyosarcoma (P < .05).CONCLUSIONS:These results indicate that lesions involving only the anterior portion of the temporal bone (petrous apex and middle ear) are more likely to be rhabdomyosarcoma. Lesions involving the mastoid are more likely to be Langerhans cell histiocytosis. This difference in primary location may be helpful in predicting the pathology of these lesions on the basis of imaging.

Rhabdomyosarcoma (RMS) and Langerhans cell histiocytosis (LCH) are both rare but potentially fatal neoplasms of the pediatric population. These diseases are distinct pathologically: RMS is a soft-tissue sarcoma arising from mesenchymal cells of the middle ear or skeletal muscle,¹ while LCH tumors arise from the abnormal proliferation of Langerhans cells (ie, dendritic cells).²Both lesions are commonly found in the head and neck region, 30%–70% in RMS³ and 60% in LCH.⁴ Less frequently, the temporal bone is involved, with only 8%–10% of cases of RMS of the head and neck³ and 19%–25% of LCH cases in this location.⁴ The initial presentation for both diseases is variable and can range from a palpable periauricular mass or external auricular canal polyps to nonspecific symptoms such as hearing loss, otalgia, or otorrhea.^3,4 Some patients may be completely asymptomatic.⁵ Because these diseases can easily mimic benign processes, the diagnoses of RMS and LCH are usually only considered after imaging reveals a skull base or temporal bone lesion. However, the imaging characteristics of these tumors are similar on both CT and MR imaging.Much of the current literature focuses exclusively on either RMS or LCH. The objective of our study was to compare radiologic data from patients with both RMS and LCH to determine characteristics that may aid clinicians in differentiating these 2 pathologies. To our knowledge, this is the first study to compare the imaging characteristics of these lesions. We hypothesized that these lesions would have distinct characteristics on cross-sectional imaging, which will aid in making the proper diagnosis. Understanding the likely pathology before an operation is undertaken will help with surgical planning. Previously held wisdom suggested that RMS lesions would arise from muscle and be most likely to affect the middle ear, given the presence of the tensor tympani and stapedius muscles in the middle ear. LCH lesions would be most likely to arise from the marrow space and therefore more commonly affect the mastoid. We designed a single blinded review of cross-sectional imaging studies in pathologically confirmed cases to determine the most common site in the temporal bone for each lesion and the type of tissue most likely affected.     

Helical CT and diagnostic evaluation of cranio-facial fibrous dysplasia]

PURPOSE: To evaluate the role of helical CT in the evaluation of skull abnormalities seen in fibrous dysplasia. MATERIALS AND METHODS: Prospective study on 6 cases with cranio-facial fibrous dysplasia (3 males and 3 females) aged 8 to 59 years old, evaluated with plain radiographs, helical CT and, in 1 case, MRI. Helical CT was performed in 3 cases on a CT Twin scan (Elscint), in 3 cases on a Somatom Plus scan (Siemens). Multiplanar reconstructions and 3D reconstructions were done in all cases. 4 cases had a histopathological confirmation of fibrous dysplasia lesions by bone-biopsy (3 cases) or surgical biopsy (1 case). RESULTS: The 6 cases included sclerotic form in 3 cases, cystic variety in 1 case, polyostotic variety in 1 case, mixed form in 1 case. Topographic localizations of fibrous dysplasia were skull base involvement in 1 case, multizonal skull involvement in 4 cases, maxillo-mandibulary involvement (cherubism) in 1 case. CONCLUSION: Helical CT is an optimal method to evaluate the skull lesions of fibrous dysplasia. The review of source images must always be done. 3-dimensional bone reconstructions are better to visualize the anterior cranial vault and skull base dysmorphy. Helical acquisition is a compromise in case by case between the dose of irradiation and the quality of source images.     

颅骨表皮样囊肿的MRI诊断

目的：探讨颅骨表皮样囊肿的MRI表现特征。方法：回顾性分析4例颅骨表皮样囊肿的MRI表现。结果：病变位于左额部1例,左额颞部1例,右颞部2例。病变区颅骨内外板膨胀变薄,局部见圆形或卵圆形破坏区,边界清楚,未见明显分隔。均呈长T1、长T2为主的混杂信号,DWI呈高信号。结论：颅骨表皮样囊肿具备一定的MRI表现特征,DWI对本病的诊断与鉴别诊断具有重要意义。     

少见部位骨母细胞瘤的影像学分析

目的：分析少见部位骨母细胞瘤的影像学表现,以期提高对本病的诊断率。方法：回顾性分析8例经病理证实的少见部位的骨母细胞瘤的影像学表现。结果：颅骨骨母细胞瘤3例,囊变明显,明显膨胀性骨质破坏,内含钙化或骨化,边缘有环形骨性包壳。鼻窦骨母细胞瘤2例,成骨明显,病变少囊变,中央为钙化或骨化,周缘为软组织。肋骨、胸骨及髂骨骨母细胞瘤各1例,均为膨胀性骨质破坏,内含钙化或骨化1例,见纤维分隔及液液平面1例。MRI上,肿瘤囊性部分T1WI呈等或低信号,T2WI呈高信号,钙化及骨化T1WI及T2WI均呈低信号。增强扫描,病变不均匀强化。病理结果,恶性2例,良性6例。结论：少见部位骨母细胞瘤的影像表现多样,缺乏特异性,当发现特殊部位膨胀性骨质破坏,内含钙化或骨化时,须考虑该病。     

CT und MRT bei intrinsischen raumfordernden Läsionen der knöchernen Schädelbasis

Intrinsic bony lesions of the skull base are diseases which arise within the bones forming the skull base. Mainly they are bone tumours and tumour-like lesions. With the exception of osteomas of the paranasal sinuses and exostoses of the external auditory canal, these lesions occur rarely. This article gives an overview of the appearance of the most common primary bony skull base masses in CT and MRI. From the authors’ point of view these are fibrous dysplasia, chordomas, chondrosarcomas, Langerhans cell histiocytosis and multiple myelomas, which must be differentiated from pseudolesions. The possibilities of CT and MRI in making a specific diagnosis, differential diagnosis and the kind of making the final diagnosis are described.