Benign bone tumors

A solid knowledge of underlying histopathology of benign bone tumors aids in differential diagnoses of these tumors. Important factors in diagnosis of a bone tumor include patient age and gender; the bone involved; the location of the tumor along, within, or on the bone; lesion margin; matrix proliferation; and periosteal reaction. This article provides a review of the origin of the tumor matrix and its influence on the imaging properties of these tumors.     

少见部位神经内分泌肿瘤的影像学表现

目的分析少见部位的原发性神经内分泌肿瘤(neuroendocrine tumor,NET)的影像学表现,以提高对该肿瘤的认识。资料与方法回顾性分析经病理证实的6例原发性NET的影像学资料,男5例,女1例,年龄51～71岁,平均58岁。肝脏、肾脏、膀胱、肠系膜各1例,胆囊2例。术前4例仅行CT检查,2例行CT和MRI检查。结果 6例中5例属于低分化神经内分泌癌(neuroendocrine carcinoma,NEC),分别位于肝、胆囊、肾及肠系膜,1例膀胱高分化NEC。肝脏原发性NET表现为大肿块伴周边多子灶,肺及腹膜后淋巴结转移,增强后呈不明显环形、分隔状强化。2例胆囊原发性NET分别为肿块型和厚壁型,肿块型1例巨大,随访晚期可见坏死,厚壁型1例黏膜中断,囊壁局限性增厚并肝脏浸润,2例强化均不明显,无腹腔内淋巴结转移。肾脏原发性NET表现为边界清楚的小结节,合并肝多发转移,增强后原发灶及转移灶均轻度强化。肠系膜NET中央坏死,增强后肿块呈轻度环形强化,灶周见肿大淋巴结,邻近肠系膜受牵拉呈辐射状。膀胱原发性NET表现为黏膜下密度不均匀结节影,MRI显示中央囊性部分呈长T1、长T2信号;病灶周壁及中间分隔呈短T...     

Extrapulmonary Tuberculosis: Imaging Features Beyond the Chest

The purpose of this pictorial review is to illustrate the various imaging findings of extrapulmonary tuberculosis. Manifestations of cardiac, central nervous system, head and neck, musculoskeletal, abdominal, genitourinary, and breast tuberculosis will be discussed. Extrapulmonary tuberculosis presents a difficult diagnostic challenge for the radiologist and requires a high index of suspicion, particularly in high-risk populations.     

Differentiating Benign from Malignant Bone Tumors Using Fluid-Fluid Level Features on Magnetic Resonance Imaging

Objective

To analyze different fluid-fluid level features between benign and malignant bone tumors on magnetic resonance imaging (MRI).

Materials and Methods

This study was approved by the hospital ethics committee. We retrospectively analyzed 47 patients diagnosed with benign (n = 29) or malignant (n = 18) bone tumors demonstrated by biopsy/surgical resection and who showed the intratumoral fluid-fluid level on pre-surgical MRI. The maximum length of the largest fluid-fluid level and the ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane were investigated for use in distinguishing benign from malignant tumors using the Mann-Whitney U-test and a receiver operating characteristic (ROC) analysis. Fluid-fluid level was categorized by quantity (multiple vs. single fluid-fluid level) and by T1-weighted image signal pattern (high/low, low/high, and undifferentiated), and the findings were compared between the benign and malignant groups using the χ² test.

Results

The ratio of the maximum length of the largest fluid-fluid level to the maximum length of bone tumors in the sagittal plane that allowed statistically significant differentiation between benign and malignant bone tumors had an area under the ROC curve of 0.758 (95% confidence interval, 0.616-0.899). A cutoff value of 41.5% (higher value suggests a benign tumor) had sensitivity of 73% and specificity of 83%.

Conclusion

The ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane may be useful to differentiate benign from malignant bone tumors.     

肾少见良性肿瘤的影像学诊断分析

目的:分析肾少见良性肿瘤的影像学表现,提高术前诊断准确性。方法:回顾性分析20例肾脏少见良性肿瘤的影像学资料,其中嗜酸细胞腺瘤9例、后肾腺瘤1例、不典型血管平滑肌脂肪瘤(AML)4例(上皮样型2例,平滑肌瘤型2例)、纤维瘤3例、中胚叶肾瘤2例、神经鞘瘤1例。15例行CT检查,3例行MRI检查,2例同时进行了CT和MRI检查。结果:本组病例除1例中胚叶肾瘤和1例神经鞘瘤外,均表现为境界清楚、均质性的实性肿块影。中央瘢痕及可以高于肾皮质的强化方式是嗜酸细胞腺瘤的特征。不典型AML、纤维瘤、后肾腺瘤及实性中胚叶肾瘤,在抑脂序列T2WI上呈较明显的低信号,且纤维瘤和后肾腺瘤都具有延迟强化的特征。良性神经鞘瘤具有境界清楚和易于发生坏死、囊变的特征。囊性中胚叶肾瘤缺少特征性的影像学表现。结论:肾少见良性肿瘤的影像学表现具有一定的特征性,有助于与肾癌进行鉴别,准确的术前诊断对指导治疗具有重要价值。     

骨原始神经外胚叶肿瘤影像学表现

目的研究骨原始神经外胚叶肿瘤的影像学特点。资料与方法搜集5例骨原始神经外胚叶肿瘤的影像及临床、手术病理资料,分析其影像学表现。结果5例中．胸椎2例,胸壁、股骨、胫骨各1例。1例胸壁病变表现为巨大软组织肿块,并推移周围组织。2例脊椎病变破坏椎管内外骨质及软组织。2例四肢长骨病变呈溶骨性骨质破坏,1例有软组织肿块。5例均未见病变内钙化及局部淋巴结肿大。MRI对显示病变组织成分及侵袭范围较X线和CT好。结论溶骨性骨破坏和巨大软组织肿块是骨原始神经外胚叶肿瘤的常见影像学表现,病灶内钙化和局部淋巴结肿大少见。MR／对显示病变组织成分及侵袭范围较好。本病最终诊断依靠病理和免疫组织化学检查。     

骨原发性恶性纤维组织细胞瘤影像诊断

目的探讨骨原发性恶性纤维组织细胞瘤(BMFH)影像表现及诊断要点。方法回顾性分析6例经病理确诊为BMFH的X线、CT及MRI表现。结果4例侵犯单骨,2例侵犯多骨。溶骨型4例,混合型2例。股骨下端3例,肱骨上端1例,楔骨1例,横突1例,共侵犯12个骨骼。6例均有骨及骨皮质明显破坏,以溶骨性破坏为主,2例病灶周围有轻度骨硬化。全部病例均有软组织肿块,巨大肿块2例,局限性肿块4例,1例肿块内可见散在小钙化影。全部病例未见骨膜反应,3例合并病理性骨折。结论原发性BMFH好发于长骨干骺端或骨端,多见于股骨下端及胫骨上端。虫蚀状或大片状溶骨性骨质破坏,巨大软组织肿块,无骨膜反应,是其影像学特点,诊断需密切结合临床和病理。     

静脉窦血栓形成的CT和MR影像特点

目的：研究静脉窦血栓形成（ＶＳＴ）的ＣＴ和ＭＲ特点。方法：对１７例ＶＳＴ的ＣＴ和ＭＲ特点进行回顾性影像分析，重点研究ＶＳＴ与皮层下多发性脑内血肿（ＳＣＭＨ）的联系，诊断与鉴别诊断。结果：ＳＣＭＨ在ＶＳＴ中出现率为１００％（１７／１７）。９例ＶＳＴ病例ＭＲ随访显示血肿、水肿和静脉窦内血栓进行性吸收，血肿周围可见规则完整的含铁血黄素沉积圈。结论：ＣＴ上急性ＳＣＭＨ是ＶＳＴ很强的一个诊断指征。ＭＲ可以进一步除外瘤卒中，发现静脉窦内血栓，以明确ＶＳＴ的诊断     

胃肠道间质瘤的影像学表现

目的:分析胃肠道间质瘤的影像学表现。方法:对16例经病理学证实为胃肠道间质瘤患者进行不同的影像学检查。结果:16例原发胃肠道间质瘤中原发于胃10例,原发于十二指肠1例,发生于回盲部1例,发生于小肠2例,横结肠系膜1例,乙状结肠系膜1例。内生性生长者1例,外生性生长者11例,腔内外生长者1例。影像学判断GIST良恶性的符合率为81%(13/16)。结论:外生性生长是胃肠道间质瘤主要的生长方式,也是诊断的主要依据。CT是该病术前诊断及判断其生物学行为的主要工具。     

Imaging Evaluation of Complications of Hip Arthroplasty: Review of Current Concepts and Imaging Findings

Total hip arthroplasty has evolved along with improvements in component materials and design. The radiologist must accurately diagnose associated complications with imaging methods and stay informed about newer complications associated with innovations in surgical technique, prosthetic design, and novel materials. This pictorial essay presents clinical and imaging correlation of modern hip arthroplasty complications, with an emphasis on the most common complications of instability, aseptic loosening, and infection as well as those complications associated with contemporary metal-on-metal arthroplasty.     

原发性骨淋巴瘤的MRI常见和特征表现

目的探讨原发性骨淋巴瘤(primary bone lymphoma,PLB)的MRI特征,以提高对该病的诊断和鉴别诊断能力。资料与方法 15例经病理证实的PLB均行MRI平扫及增强扫描。镶边征定义为增强扫描时病变骨大片均匀低信号,边缘花边样明显强化;骨皮质开窗征定义为骨内病变与骨外软组织肿块通过一较小的窗口样皮质破坏区相连。结果 (1)病灶内出现镶边征13例,占93.33%,骨皮质开窗征11例,占73.33%。(2)病理上,骨皮质开窗征是由于瘤细胞在骨髓腔内浸润或渗透性生长,骨皮质内骨小梁保存,故骨皮质轮廓大部完整,当瘤细胞局灶破坏骨小梁,使骨皮质溶解性改变而呈现开窗征;镶边征可能是由于中心片状坏死呈低信号,周围肉芽增生血供丰富,呈现花边样明显强化。结论 骨皮质开窗征和镶边征在PLB的MRI表现中出现率高,可作为诊断PLB的常见和特征表现。     

头颈部良性神经源性肿瘤1H MRS的表现特点

目的：探讨头颈部良性神经源性肿瘤在单体素^1H MRS上的表现特点。材料和方法：共收集经单体素。HMRS检查，并经手术病理证实的头颈部神经源性肿瘤14例（神经鞘瘤11例，神经纤维瘤2例，颈动脉体瘤1例）。采用点分析波谱法（PRESS：TE=144ms，14例）和激励回波法（STEAM：TE=30ms，11例）进行。HMRS空间定位，以胆碱和脂质代谢物为标准评价所有肿瘤。波谱图上，胆碱和脂质分别在3．2ppm和0．9—1．4ppm区域识别。结果：采用PRESS后，14例神经源性肿瘤中检测出胆碱代谢物者11例，检出脂质代谢物者6例。胆碱和脂质代谢物同时检出者5例，仅检出胆碱者6例，仅检出脂质者1例，胆碱和脂质均未检出者2例。采用STEAM后，11例肿瘤中检出胆碱代谢物和脂质者分别为3例和8例。结论：头颈部良性神经源性肿瘤的单体素。HMRS表现具有多样性，多数肿瘤以长TEPRESS上胆碱峰的显示为特点，长TEPRESS能较STEAM更好地检出良性神经源性肿瘤内的胆碱代谢物。     

骨小圆细胞肿瘤的影像学分析

目的探讨骨小圆细胞肿瘤(small round cell tumor of bone,SRCT)的影像学特征及鉴别诊断,旨在提高对该病的认识及诊断水平。方法回顾性分析28例经病理证实的SRCT的影像表现。13例行X线平片检查,19例行CT检查,17例行MRI检查。结果 28例中,淋巴瘤10例,尤文氏肉瘤6例,浆细胞肿瘤6例,原始神经外胚层肿瘤4例,小细胞型骨肉瘤1例,间充质软骨肉瘤1例。CT、MRI表现为不同程度的骨质破坏,多数破坏较轻,但灶周软组织肿块较大且大于骨侵犯范围。结论 SRCT既有类似的影像学表现,各自也有其影像学特征,综合临床,可做出初步诊断,确诊需病理、免疫组织化学检查。     

Unusual Malignant Solid Neoplasms of the Kidney: Cross-Sectional Imaging Findings

Malignant kidney neoplasms are the most frequently encountered solid kidney masses. Although renal cell carcinoma is the major renal malignancy, other solid malignant renal masses should be considered in the differential diagnosis of solid renal masses that do not contain a macroscopic fatty component. In this pictorial essay, we present the imaging findings of a primitive neuroectodermal tumor, primary liposarcoma of the kidney, primary neuroendocrine tumor, leiomyosarcoma, synovial sarcoma, malignant fibrous histiocytoma, sclerosing fibrosarcoma and renal metastasis of osteosarcoma.     

髓内肿瘤的磁共振诊断与鉴别诊断

本文通过对30例髓内肿瘤和20例非肿瘤病变MR表现的回顾性对比分析,总结了髓内肿瘤MR诊断和鉴别诊断经验。指出髓内肿瘤的MR主要征象为脊髓局部增宽、膨大,病灶Gd-DTPA明显强化,以及伴有囊变。而非肿瘤病变脊髓轮廓改变较轻,Gd-DTPA为轻至中度强化。增强特点为偏心性、点片状或环状,较具特异性。     

Thinking Beyond Peritoneal Carcinomatosis: Imaging Spectrum of Unusual Disseminated Peritoneal Entities

Although peritoneal carcinomatosis is the most common entity involving the peritoneum diffusely, a vast array of unusual diseases may affect the peritoneal surfaces. These entities can be further categorized into infectious, neoplastic, and miscellaneous conditions. Cross-sectional imaging, including computed tomography and magnetic resonance imaging are excellent modalities for further characterization of these unusual diseases. For some of these conditions, imaging-specific diagnosis is achievable. For others, the diagnosis can be favored when clinical and/or cross-sectional imaging features coexist.     

骨内脂肪瘤的影像学诊断

目的:讨论骨内脂肪瘤的发病机制、临床特征、影像表现、诊断及鉴别诊断.方法:回顾性分析经手术病理证实的11例骨内脂肪瘤的临床及影像资料,11例均行X线、CT检查,2例行MRI检查.结果:X线平片表现边界清晰的不规则形透亮区,可伴硬化缘.CT上病灶为类圆形或不规则形的脂肪密度区,CT值-55～-120 HU,病灶边界不规则,伴有厚薄不一的硬化缘,5个病灶中心可见结节状钙化灶.MRI表现为T1WI高信号,T2WI稍高信号,脂肪抑制序列病灶信号受抑变低,边缘见长T1短T2信号,其内见线条状长T1短T2信号的纤维分隔及长T1长T2的液性囊腔.结论:结合发病年龄、病变部位、临床症状和影像学表现,对本病可作出正确的术前诊断,可避免不必要的穿刺活检和CT、MRI的重复检查.