MRI in intraspinal tuberculosis

We studied 20 patients with intraspinal tuberculosis (TB), to characterise the MRI features of tuberculous meningitis and myelitis. MRI leptomeningitis and intramedullary involvement in 11 patients, intramedullary lesions alone in 5, leptomeningitis alone in 2, and isolated extradural disease in 2. TB leptomeningitis was characterised by loculation of the cerebrospinal fluid (CSF), nerve root thickening and clumping (seen only in the lumbar region) or complete obliteration of the subarachnoid space on unenhanced images. Gd-DTPA-enhanced images proved useful in 6 cases, revealing linear enhancement of the surface of the spinal cord and nerve roots or plaque-like enhancement of the dura-arachnoid mater complex. Intramedullary lesions included tuberculomas (8), cord oedema (5) and cavitation (3). In seven cases of intramedullary tuberculoma multiple lesions with skip areas were seen, without significant cord swelling. One patient had an isolated lesion in the conus medullaris. The lesions were iso- or hypointense on T1-weighted images, iso-, hypo- or hyperintense on T2-weighted images and showed rim or nodular enhancement with contrast medium.     

脊髓结核瘤的MR I表现分析并文献复习

目的：分析脊髓结核瘤的 MRI表现并文献复习。方法回顾性分析5例经临床和影像证实的脊髓结核瘤患者 MRI表现,所有患者MRI检查包括T1 WI、T2 WI平扫和T1 WI增强扫描,观察病变的部位、信号特点、强化方式和形态。结果1例病变位于颈段脊髓,为稍长T1、短T2信号,呈结节样强化;3例病变位于下胸段脊髓,横断位T2 WI表现为典型的“靶征”,增强后呈环状强化,矢状位其长轴与脊髓长轴一致,其中1例增强后发现合并1个平扫不能显示的粟粒强化结节;1例病变位于脊髓圆锥,为长 T1、短T2信号,增强后呈环状强化。结论脊髓结核瘤 MRI表现具有多样性,其特征性表现包括 T2 WI 低信号或“靶征”、环状强化、病变长轴与脊髓长轴一致。     

脊髓室管膜瘤的MRI表现

目的探讨脊髓内室管膜瘤的MRI表现,提高对本病的认识。方法收集我院经病理证实的脊髓室管膜瘤13例,分析肿瘤部位、信号特点、有无囊变、出血及帽征、椎间孔扩大及肿瘤强化方式。结果肿瘤位于颈髓6例,胸髓3例,终丝及马尾4例.在T1WI上呈等、低信号,在T2WI上呈高信号、混杂信号.9例见囊变,3例可见肿瘤内出血,2例椎间孔扩大.13例均出现不同程度强化,1例呈轻度强化,3例中度强化,9例重度强化,11例肿瘤与正常脊髓分界清楚。结论髓内室管膜瘤MRI表现具有一定特点,结合其发病部位、边界、囊变、出血、强化特征及临床资料常可作出正确诊断。     

肝结核瘤的MRI征象

目的 分析肝结核瘤的MRI表现，探讨MRI在鉴别诊断中的价值。资料与方法 10例肝结核瘤患者行MR自旋回波序列T1WI、T2WI和快速多层面干扰梯度回波序列动态增强扫描。结果 10例共12个病灶，MRI表现：（1）自旋回波序列：T1WT上所有病灶为低信号，T2WI上10个病灶为不均匀低信号（8个病灶为中心低信号而边缘为环形或片状的高信号，2个为低信号中见到点状高信号），另2个病灶为高信号。（2）增强扫描：动脉期10个病灶无强化,2个病灶边缘有轻度强化。门脉期和延迟期所有病灶均有不同方式的强化，主要为边缘强化和分隔强化。结论 MRI可反映肝结核瘤的病理改变过程，在诊断和鉴别诊断中有重要价值。     

Magnetization transfer MR imaging correlation with histopathology in intracranial tuberculomas

OBJECTIVE: The purpose of this study was to correlate the differences in the magnetization transfer (MT) ratios of different components of the tuberculoma with histopathology and to see whether MT or conventional MR imaging correlates better with histopathology. METHODS: MT T1 and conventional spin echo MR imaging was performed in six patients with intracranial tuberculomas. The tuberculomas were excised as a single mass and ex vivo MR imaging was performed using the same protocol. The gross histopathology was compared with in vivo imaging with respect to the MR signal intensity (MT ratio) in all six specimens. RESULTS: The size of the tuberculomas was larger on MT T1-weighted images compared to T2-weighted images and matched the gross measurements of each specimen. The MT hyperintense rim matched the cellular component of the tuberculoma that was masked on T2-weighted images because of the associated perifocal oedema. The cellular component had a lower MT ratio compared to the necrotic components. CONCLUSION: The outer hyperintense rim and hyperintense strands are due to the cellular infiltrate, noncaseating granulomas, and gliosis while the hypointense core represents solid caseation. The cellular outer rim shows lower MT ratio compared to the core of the tuberculoma. Histological correlation of the cellular and necrotic components of tuberculomas is best shown with MT T1 imaging.     

颞下窝原发肿瘤的CT及MR表现

目的：探讨颞下窝原发肿瘤CT及MRI表现。方法回顾性分析20例经病理证实的颞下窝原发肿瘤的CT及MR资料。结果颞下窝肿瘤形态多不规则。神经鞘瘤多边界清楚（5/6）,MR T1WI为等信号,T2WI为高信号肿物伴线状分隔样低信号,2例通过卵圆孔伸入中颅窝呈哑铃状生长。恶性外周神经鞘膜肿瘤边界多不清楚（4/5）,MR T1WI为等信号,T2WI为不均匀高信号,病变可侵犯邻近肌肉及骨质。横纹肌肉瘤MR T1WI为等信号,T2WI为高信号。孤立性纤维性肿瘤边界清楚,MR T1 WI等信号,T2 WI为混杂略高信号,增强后较明显强化。腺样囊性癌边界不清,沿神经浸润生长。侵袭性多形性腺瘤MR T1 WI为等、低信号,T2 WI为高信号,侵犯邻近肌肉。淋巴瘤形态不规则,边界清楚,MR T1WI为低信号,T2WI为中高信号,轻度强化,内有线样血管影穿行。结论熟悉颞下窝原发肿瘤CT及MRI表现,有助于提高该部位病变诊断及鉴别诊断水平。     

Disseminated tuberculomas in spinal cord and brain demonstrated by MRI with gadolinium-DTPA

Summary Intramedullary tuberculoma is rare, and there has been no report of concurrent intramedullary and intracerebral tuberculomas. We report a 30-year-old man with miliary tuberculosis of the lung. He suffered sudden paraplegia due to tuberculomas in the thoracic spinal cord and MRI showed more tuberculomas in the cervical spinal cord, brain stem, and cerebral and cerebellar hemispheres. The tuberculomas were isointense on the T1-weighted images, and hyperintense on the T2-weighted images; there was marked enhancement with intravenous gadolinium-DTPA. All the tuberculomas were very small 1 year after antituberculous chemotherapy.     

Intracranial tuberculoma: comparison of MR with pathologic findings.

PURPOSETo compare the MR signal intensity patterns and enhancement pattern of intracranial tuberculomas with their histopathologic features.METHODSMR images of six patients with surgically proved intracranial tuberculoma were reviewed retrospectively and were compared with histologic findings of the resected specimen. Detailed histologic examination was performed to look for the extent and characteristics of caseation necrosis, fibrosis, and inflammatory cellular infiltrates at each area of different signal intensities and at the enhancing areas on MR. Signal intensities for T1- and T2-weighted images were compared with normal gray matter.RESULTSOn T1-weighted images, the granulomas showed a slightly hyperintense rim surrounded by a complete or partial rim of slight hypointensity and central isointensity or mixed isointensity and hyperintensity in five patients and homogeneous isointensity in one patient. Histologically, the zone of central isointensity or mixed intensity corresponded to caseation necrosis plus adjacent cellular infiltrates. The hyperintense and hypointense rims corresponded to the layers of collagenous fiber and the layers of the inflammatory cellular infiltrates, respectively. On T2-weighted images, the entire portion of the granuloma showed slightly heterogeneous isointensity or hypointensity with small markedly hypointense foci in five patients, and a hyperintense center surrounded by a hypointense rim in one patient. Histologic layers were not discriminated on T2-weighted images. On postcontrast T1-weighted images, there were single or multiple conglomerate ring enhancements within a tuberculoma in all six patients, corresponding to the layers of both collagenous and inflammatory cells.CONCLUSIONCombination of the described signal intensity patterns and conglomerate ringlike enhancing appearance of the lesion is characteristic of tuberculoma, and may play an important role in differentiating intracranial tuberculomas from other ring-enhancing brain lesions.     

脑结核瘤的MRI诊断及其临床价值

目的：研究磁共振成像(MRI)对脑结核瘤的影像学诊断及其临床价值。方法：回顾性分析了12例经手术、病理或抗结核治疗随访证实为脑结核瘤病人的MRI及其临床资料。采用0．3T低场永磁型设备，行常规SET1WI、FSET2WI，其中11例行钆喷替酸葡甲胺(Gd-DTPA)增强扫描。10例行CT检查，其中6例行CT增强扫描。结果：本组12例共发现病灶32个，单发7例，多发5例，其中1例合并粟粒性结核瘤。将脑结核瘤的MRI表现不同分为2种类型。T1WI呈等或略高信号、T2WI呈等或略低信号，明显结节样强化或不均匀环状强化是脑结核瘤较具特征性的MRI表现，环内核心部分呈T2WI低信号对诊断更有价值。针对脑结核瘤的不同类型采取抗结核药物或手术切除等不同的治疗方法。结论：脑结核瘤有较特征性的删表现，并可指导临床采取不同的治疗方法。     

MRI of brain abscesses

Four cases of brain abscess were examined on 1.5T MR and their findings were evaluated retrospectively. Preoperative cases had relatively characteristic findings, such as 1) peripheral edema producing hypointensity on T1-weighted images (T1WI) and hyperintensity on T2-weighted images (T2WI); 2) central necrosis with abscess fluid hypointense relative to white matter on T1WI and hyperintense on T2WI; 3) abscess rim iso- to hypointense on T2WI. Gd-DTPA enhanced T1WI carried further information; comparison of iso- to hypointense rim on T2WI (abscess rim) and enhanced area by Gd-DTPA on T1WI suggested that the former represented zone of macrophage infiltration.     

MR imaging of solitary pulmonary lesion: emphasis on tuberculomas and comparison with tumors

The aim of this study was to determine whether solitary pulmonary tuberculoma and malignant tumor can be differentiated on the basis of magnetic resonance (MR) signal intensity. Twenty-eight patients with solitary pulmonary lesions were prospectively studied with MR imaging: T1-weighted, enhanced T1-weighted, proton density-weighted, and T2-weighted spin echo images were obtained. The confirmation methods used were computed tomography (CT)-guided biopsy in seven patients with lung cancer and four patients with tuberculosis; surgery in ten patients with lung cancer and five patients with tuberculosis; and laboratory data in two patients with tuberculosis. Morphologic features and MR signal intensity were examined in detail. As the test for detection of tuberculoma, signal difference on T2-weighted images was carefully analyzed. The signal intensity ratio of the nodule to thoracic muscle signal intensity was measured. The signal intensities obtained from the lung cancers and tuberculomas were variable on pre-and post-enhanced T1-weighted images and proton density-weighted images. Masses were hypointense in 2 of 17 patients with lung cancer and in 9 of 11 patients with tuberculoma on T2-weighted images (sensitivity 82%, specificity 89%, accuracy 87%). The mean signal intensity ratios of the tuberculomas to muscle were significantly lower than those of malignant tumors on T1-weighted, enhanced T1-weighted, proton density-weighted, and T2-weighted images (P < 0.0001). After gadolinium-DTPA enhancement, 2 malignant tumors and 7 tuberculomas showed a marginal rim enhancement pattern, whereas 15 malignant tumors and 2 tuberculomas revealed a diffuse enhancement. The results of MR imaging were consistent with those of CT in 84% of the patients. MR imaging is a helpful adjunctive method in terms of differentiating a tuberculoma from a malignant tumor.     

布氏杆菌性脊椎炎的MRI表现

目的探讨MRI对布氏杆菌性脊椎炎的诊断价值。资料与方法 16例经临床或手术病理证实的布氏杆菌性脊椎炎行T1WI、T2WI、STIR及增强检查,分析其形态及信号特点。结果病变累及腰椎最多。椎体形态多无明显变化,椎体边缘可见小的骨质破坏及骨质增生。病变椎体T1WI呈低信号,T2WI呈低等或等高信号或低等高混杂信号。STIR呈高信号。增强扫描病变椎体明显强化,与周围正常增强的椎体信号类似或更高。椎间盘7例变窄,信号变化不显著,呈等T1、等T2信号(与邻近椎间盘比较),只有2例T2WI呈高信号。16例均有椎管外软组织受累,呈不均匀长T1、长T2信号,边界模糊,STIR呈混杂高信号,内可见多发大小不等的脓腔,增强扫描显示脓腔壁厚薄不均不规则强化。10例有不同程度椎管内硬膜外脓肿,呈长T1、长T2信号,STIR呈高信号。增强扫描显示脓壁厚薄不均明显强化。脓肿范围较小,一般不超过病变椎体节段。结论布氏杆菌性脊椎炎MRI表现有一定的特征性,MRI对布氏杆菌性脊椎炎诊断及鉴别诊断有重要价值。     

脊髓室管膜下瘤的MR影像诊断

目的 研究脊髓内室管膜下瘤的MRI特征。方法 4例脊髓室管膜下瘤均行MR检查并经手术病理证实，均为男性，年龄15—47岁，平均36．3岁。回顾性分析脊髓内室管膜下瘤的MRI表现，结合术中所见总结MRI诊断与鉴别诊断要点。结果 4例脊髓内室管膜下瘤分别位于C3～T3、C2～6、T6～12、C1—T2段脊髓，肿瘤均位于脊髓腹侧，呈偏中心性生长。1例有轻度脊髓空洞。MR T1WI为等或低信号，信号不均，内有更低信号；T2WI为高信号。2例伴有小出血灶。增强扫描，3例肿瘤无强化或强化轻微，1例强化明显。结论 MRI可以很好评价脊髓内室管膜下瘤，当患者具备上述特点时高度提示脊髓内室管膜下瘤的可能。     

原发性透明细胞型肝癌的CT和MRI诊断

目的 探讨原发性透明细胞型肝癌的影像表现,评价CT和MRI对该病的诊断价值.方法 回顾性分析19例经手术病理证实的原发性透明细胞型肝癌的CT和MRI表现.13例行CT平扫和动态增强扫描,8例行MR T1WI、T2WI和动态增强扫描.结果 CT平扫13例病灶均为低密度,其中9例病灶内部见不规则的更低密度影.增强后动脉期所有病灶均有强化表现,9例病灶不均匀强化,病灶中心有无强化的低密度区.门静脉期11例病灶呈相对低密度,2例呈等密度.3例可见环形强化的包膜.MR T1WI上5例病灶为低信号,3例为稍高信号.T2WI上5例病灶为混杂高信号,3例为等、低信号.MRI增强动脉期所有病灶均有显著强化.门静脉期和延迟期7例病灶为相对低信号,1例为等信号.2例病灶见环形强化的包膜.结论 CT和MRI可显示原发性透明细胞型肝癌的特征性表现,有助于提高该病的诊断准确性.     

脊髓多发性硬化的MRI诊断与鉴别诊断

目的　提高对脊髓多发性硬化MRI特征的认识。方法　对 15例脊髓多发性硬化患者行颈部MRI检查。对病变的位置、长度、横断面上病变大小及病变的强化进行评价 ,并与脊髓内肿瘤、脊髓型颈椎病、急性横贯性脊髓炎的MRI表现进行比较。结果　 15例脊髓多发性硬化主要发生在颈段脊髓 ,病变一般少于 5个椎体长度 ,MRI特点为矢状位脊髓局限性梭形增粗 ,边缘光滑。T1WI呈等或界限模糊的稍低信号 ,T2 WI呈长短不一的条形高信号。轴位像病灶位于脊髓侧方和后方 ,一般小于脊髓截面 1/2。活动期病灶呈条、片状强化 ,但强化区范围明显小于T2 高信号灶范围。反复发作病例多发病灶强化多样性 ,也可不强化。结论　脊髓多发性硬化有其特征性MRI表现 ,能为临床诊断提供可靠的依据     

原发性肝细胞癌射频消融治疗后MR动态随访研究

目的 探讨原发性肝细胞癌射频消融(RFA)治疗后的MR随访表现特征及规律.方法 回顾性分析2008年8月至12月住院的110例原发性肝细胞癌患者RFA治疗后的MR资料,根据MR检查时间分为3组:消融后48 h内、1～6个月、6个月以上.采用卡方检验分析比较肝细胞癌RFA治疗后肿瘤MR表现的动态变化.结果 110例短期(48 h内)RFA区域在GRE-TtWI表现为高信号,快速自旋回波(TSE)-T2WI则呈低信号,增强扫描无强化.1～6个月,GRE-T1WI示RFA区域信号呈不均匀下降,72例呈高信号,4例呈等低信号;＞6个月时,60例呈高信号,17例呈等低信号,此改变在6个月后与48 h内和1～6个月比较差异均有统计学意义(P值均＜0.015).TSE-T2WI示RFA区域信号呈不均匀轻度增高,1～6个月,65例呈低信号,11例呈等信号;＞6个月时,47例呈等信号,30例呈低信号,而此信号改变在6个月后与48 h内和1～6个月比较差异均有统计学意义(P值均＜0.015).增强后早期RFA区域主要表现为环状强化伴或不伴异常灌注,而随着时间延长趋向无强化,1～6个月,37例无强化;＞6个月,63例无强化,此改变在3组间差异均有统计学意义(P值均＜0.015).6例肿瘤残留或局部进展,表现RFA区边缘结节,TSE-T2WI抑脂像呈中等高信号,GRE-T1WI呈低信号并伴有不同程度的强化.结论 原发性肝细胞癌RFA治疗后,动态MR随访能显示肿瘤完全坏死、肿瘤残留或局部进展及并发症的相关特征.     

MR imaging of stereotactic thalamotomy using radiofrequency methods]

Sixty-eight stereotactic radiofrequency (rf) thalamic lesions in 57 patients with movement disorders were evaluated by magnetic resonance (MR) imaging. Postoperative periods ranged from 5 days to 4 years and 9 months. All 68 rf lesions were clearly detected on T2-weighted images (T2WI). Changes in signal intensity on T2WI were classified into five patterns, as follows: Pattern I: lesions with three concentric zones consisting of an inner hypointense, middle hyperintense and outer hypointense zone (31 lesions); Pattern II: lesions consisting of an inner hypointense and outer hyperintense zone (4 lesions); Pattern III: lesions consisting of an inner hyperintense and outer hypointense zone (27 lesion); Pattern IV: lesions of a hyperintense area alone (2 lesions); Pattern V: lesions of a hypointense area alone (4 lesions). The outer hypointense rim in Patterns I and III is thought to represent hemosiderin deposition. The abnormal signal intensity on T2WI caused by rf ranged from 2 to 12 mm in diameter, and lesions in the late phase were smaller than lesions in the early phase.     

MR Imaging in intramedullary cysticercosis

Although intramedullary spinal cord cysticercosis (IMC) is uncommon, its presence is being increasingly recognised by magnetic resonance imaging. We studied six patients from an endemic region and present the MRI features and clinical correlation of IMC. Six patients who presented with para- or quadriplegia were studied by contrast enhanced spinal MRI. Prompted by the spinal lesions, all patients underwent brain MRI. Clinical data and laboratory studies were reviewed in all patients. Definite diagnosis was established in the form of response to drug therapy (n = 4) and histopathology (n = 2). Follow-up MRI studies of spine and brain were obtained in four patients 2 months after they started medical treatment, regardless of surgery. Five patients showed fusiform and focal enlargement of the spinal cord (cervical 2, thoracic 3). Well-defined cysts with a slightly hyperintense mural nodule were identified in five patients in Ti-weighted images (T1WI). All cysts were hyperintense on T2WI and merged with the surrounding oedema. Oedema extended one to three vertebral levels above or below the cyst. Post-contrast T1WI showed well-defined, ring enhancing lesions with smooth walls in all patients. Symptoms in all patients correlated with the level of the lesions. Brain studies demonstrated lesions in just two patients. Histopathological confirmation was obtained in two patients. Follow-up spinal MRI was normal in two patients, following 2 months of treatment while residual and smaller lesions were seen in two patients. Two patients were asymptomatic and denied follow-up MRI. MRI of spinal cysticercosis were typical of and similar to those seen in cerebral lesions in our patients and corresponded to the level of symptoms. All cysts were surrounded by oedema. Two of four patients showed residual lesions after 2 months of therapy and 33 % of patients showed concomitant intracranial lesions.     

肝硬化结节与小肝癌的MRI研究

目的:回顾性分析肝硬化合并小肝癌、再生结节(RN)及肝不典型增生结节(DN)的MR表现,探讨其MR诊断与鉴别诊断。方法:收集50例结节性肝硬化病例MR检查资料,患者行正反相位T1WI、脂肪抑制T2WI、动态增强扫描和弥散加权(DWI)扫描,总结肝内结节的信号特点。结果:RN在T1WI脂肪抑制上多为等信号或稍高信号,T2WI多为低信号,增强后与周围正常肝组织强化相似或信号稍低;DN在T1WI多为较高信号,T2WI多为稍低或等信号,增强后强化不明显;癌结节T1WI多为稍低或等信号,偶有稍高信号,T2WI多为较高信号,DWI为高信号,强化多为动脉中晚期强化,门静脉期以后强化减退。结论:磁共振平扫加动态增强能对大多数RN、DN和小肝癌结节做出明确诊断和鉴别。     

Magnetization transfer MR imaging in CNS tuberculosis.

BACKGROUND AND PURPOSE: CNS tuberculosis may simulate other granulomas and meningitis on MR images. The purpose of this study was to improve the characterization of lesions in CNS tuberculosis and to assess the disease load using magnetization transfer (MT) imaging. METHODS: A total of 107 tuberculomas in seven patients with or without meningitis and 15 patients with tuberculosis meningitis alone were studied. Fifteen patients with cysticercus granulomas with T2 hypointensity, five patients each with viral and pyogenic meningitis, and two patients with cryptococcal meningitis were also studied. The MT ratios were calculated from tuberculomas, cysticercus granulomas, and thickened meninges in tuberculous, viral, pyogenic, and cryptococcal meningitis and were compared within each pathologic group and with the MT ratio of different regions of normal brain parenchyma. Detectability of lesions on T1-weighted MT spin-echo (SE) images was compared with that on conventional SE and postcontrast MT-SE images. RESULTS: Thickened meninges appeared hyperintense relative to surrounding brain parenchyma in the basal and supratentorial cisterns on precontrast MT-SE images in all 18 patients with tuberculosis meningitis. These meninges were not seen or were barely visible on conventional SE images, and enhanced on postcontrast MT-SE images. The MT ratio from the thickened meninges of tuberculous meningitis was significantly lower than that from the meninges in cryptococcal and pyogenic disease and significantly higher than the meninges in viral meningoencephalitis. The MT ratio from T2 visible and invisible tuberculomas appeared to be significantly lower than that of normal white matter. The MT ratio of T2 hypointense cysticercus granuloma was significantly higher than that of T2 hypointense tuberculoma. CONCLUSION: Precontrast MT-SE imaging helps to better assess the disease load in CNS tuberculosis by improving the detectability of the lesions. With the use of MT ratios, it may be possible to differentiate tuberculosis from similar-appearing infective lesions on MR images.