Follow-up CT and MR findings of osteoblastic spinal metastatic lesions after stereotactic radiotherapy

Purpose

We retrospectively analyzed pre and post-stereotactic radiotherapy CT and MRI findings and volume changes for osteoblastic spinal metastatic lesions.

Materials and methods

Of 114 lesions in 72 patients, 11 were osteoblastic. CT and MR images were reviewed to determine tumor volume, CT attenuation, T2 signal intensities, and contrast enhancement.

Results

Tumor volume did not change for 10 lesions and increased for 1 lesion. CT attenuation increased for 8 lesions with heterogeneous T2 signal intensities. Of these 8 lesions, 4 had patterns of dark signal foci and the other 4 had patterns of both dark and bright signal foci. T2 signal intensity became heterogenous, with dark and bright foci, for 2 of 3 lesions for which CT attenuation decreased, and normalized for the third lesion. The degree of contrast enhancement decreased for 6 lesions and did not change for 5 lesions.

Conclusion

There were no changes in volume except for one case. On CT images, sclerotic changes were more common than loss of sclerotic foci. On T2-weighted images, dark signal intensities with or without bright signal foci developed and the degree of enhancement decreased for more than half of the cases.     

脑脂肪栓塞的CT和MRI诊断(附3例分析)

目的 :分析脑脂肪栓塞 (CFE)的CT和MRI表现 ,以提高对此病的早期诊断。方法 :对 3例CFE患者的临床及CT和MRI资料进行分析。结果 :3例CFE患者CT检查均为阴性 ,MRI示双侧额叶皮层下脑白质区、基底节、放射冠、半卵圆中心区多发散在点状异常信号影 ,1例T1WI表现为低信号 ,2例未见异常 ,3例T2 WI均表现为点状较高信号 ,DWI上 3例均有点状高信号。结论 :有近期骨折病史者 ,一旦出现神经系统症状 ,要想到CFE的可能 ,应早期行颅脑MRI检查 ,常规选择T1WI、T2 WI和DWI多种序列成像技术进行检查。     

Desmoplastic small round cell tumor: imaging findings associated with clinicopathologic features

PURPOSE: To describe imaging findings of desmoplastic small round cell tumor (DSCRT) and to clarify the relation between radiologic appearances and clinicopathologic features. MATERIALS AND METHODS: CT scans and MRI examinations of four male patients with histologically confirmed DSCRT (mean age = 20 years) were retrospectively analyzed. RESULTS: The common imaging finding was multiple peritoneal masses with regular contour situated within mesentery. Tumors showed central low attenuation in 75% of patients on nonenhanced CT. All tumors showed inhomogeneous enhancement on CT. Small foci of punctate calcification were identified in a part of the tumor in all patients. Bone metastases were identified on enhanced CT in two patients 2 and 8 months after diagnosis, respectively. Pleural dissemination was identified in all patients, and one patient had double-sided dissemination. T2-weighted MRI showed inhomogeneous high signal intensity, and small cysts were identified in two patients. Fluid-fluid levels were identified in six tumors on T2-weighted images, which suggested the presence of hemorrhage. Tumors had inhomogeneous signal intensity low or isointense relative to skeletal muscle on T1-weighted images. Two lesions exhibited inhomogeneous enhancement with central low intensity consistent with necrosis. CONCLUSION: Imaging studies can depict disseminated characteristics and disease extent during the clinical course of DSRCT.     

Differentiation of proximal bronchogenic carcinoma from postobstructive lobar collapse by magnetic resonance imaging. Comparison with computed tomography

MRI and CT studies in 18 patients with proximal bronchogenic carcinoma and postobstructive lobar collapse were analyzed retrospectively. The relative abilities of these imaging techniques to identify central tumor by a contour abnormality and to distinguish tumor mass from collapsed lung by CT attenuation values and MRI signal intensities were compared. MRI and CT were equivalent in their ability to identify a contour abnormality, both succeeding in 13 of 18 (72%) patients. CT was more successful than MRI in differentiating tumor mass from collapsed lung. Dynamic computed tomography scanning differentiated tumor from collapsed lung in eight of ten (80%) patients. MRI demonstrated different signal intensities of tumor and collapsed lung in 8 of 18 (44%) patients. T2-weighted images more often separated tumor from collapsed lung than other imaging sequences.     

MR and CT in the evaluation of sarcoid myopathy

Sarcoid myopathy is a relatively rare extrapulmonary complication of sarcoidosis. We evaluated the diagnostic utility of MR at 1.5 T in four patients with sarcoid myopathy of the lower extremities established by biopsy. Two of the patients were of the "atrophic type" and two of the "nodular type." The findings on MR were compared with the findings on CT, gallium scanning, and electromyography. Only MR was positive in all cases. The T2-weighted scans (spin echo 2,000/80) revealed two distinctly different patterns of abnormality (i.e., discrete foci of high signal intensity lesions in the patients with the nodular type of sarcoid myopathy and atrophic muscle of high signal intensity in the patients with the atrophic type). Due to its ability to provide objective findings of the extent and distribution of muscle involvement, MR should prove useful in the detection, diagnosis, and monitoring of sarcoid myopathy.     

胚胎发育不良性神经上皮瘤的影像学与临床病理特征

目的探讨胚胎发育不良性神经上皮瘤（DNT）的MRI、CT表现及临床病理特征。方法回顾性分析经组织病理学证实的12例DNT的MRI、CT表现与临床病理特点。结果男6例，女6例，年龄12～68岁（平均36．7岁）。大多数病例以癫痫小发作为主，神经系统检查无阳性体征。MR检查病变均位于幕上结构，累及皮层，额叶（4例）及颞叶（3例）为主；最大径2-5cm不等，形态呈类圆形、分叶状或不规则状；2例累及白质，7例伴囊性变。病变在MRI均呈T1WI低信号，T2WI高信号，无病变周围水肿及占位效应；囊性病变在T1WI信号均匀，等于或略高于脑脊液。6例CT扫描病变均呈低密度改变，其中2例呈囊性分叶状，1例呈局灶性钙化；4例增强后病变无强化，1例病变内呈轻度不均匀强化。病理组织学DNT分为3型：单纯型（4例）、复杂型（6例）及非特异型（2例）。结论DNT是一种良性病变，MRI较CT更具特征性表现。     

Cavernous hemangioma of the intracranial optic pathways: CT and MRI.

PURPOSE: The purpose of this work was to describe the CT and MR findings in three patients with cavernous hemangioma (CH) of the intracranial optic pathways. METHOD: CT and MR studies of three patients with CH of the optic chiasm were reviewed. All patients underwent MRI of the chiasmal area, with coronal T2- and T1-weighted studies as well as gadolinium-enhanced coronal and sagittal T1-weighted studies. RESULTS: The patients (mean age, 40 years) presented with chiasmal apoplexy (two cases) and progressive decrease of visual acuity (one case). In all cases, MRI showed regular enlargement of the optic chiasm, with extension to the optic nerve in one case and to the left optic tract in one case. The chiasmatic dimension was 2.5-3 cm in two cases and 1-1.5 cm in the other case. In all cases, MRI revealed an acute (isointense signal on T1-weighted and hypointense signal on T2-weighted sequences) or subacute (hyperintense signal on T1 - and T2-weighted sequences) hemorrhage with, adjacent to it, an area with signals of blood of different ages, highly suggestive of CH. CT showed, in chiasmatic CHs, a suprasellar mass spontaneously denser than adjacent brain parenchyma. In two cases, microcalcifications were associated. In two cases, CT and MRI revealed slight heterogeneous enhancement after contrast agent administration. In one case, no enhancement was observed. Two patients underwent surgery by frontopterional craniotomy. The optic chiasms were swollen with an intrinsic bluish mass. The cerebrospinal fluid was not xanthochromic. Microscope examination confirmed the diagnosis of CH. After 12 months, the operated patients had improved visual acuity and visual field but did not completely recover. The nonoperated patient (because of spontaneous rapid recovery of visual acuity) was followed clinically and on MRI over 18 months. CONCLUSION: CH in the optic chiasm must be suspected in the presence of an acute chiasmatic syndrome. MRI is the best imaging modality, showing either an acute or a subacute chiasmatic hemorrhage or the typical pattern of CH with heterogeneous alternation of foci of blood of different ages, with a central focus of methemoglobin, a peripheral rim of hemosiderin, adjacent foci of acute or subacute hemorrhage, and slight or no enhancement after gadolinium administration.     

Magnetic resonance imaging of chronic myocardial infarcts in man

To evaluate the magnetic resonance imaging (MRI) features of chronic myocardial infarction (MI), 22 patients and several normal volunteers were studied with a 0.35-T cryogenic imaging system. The MIs were 9 months to 16 years old. The patients also had either left ventriculography (17 patients) or two-dimensional echocardiography (17 patients). At least one abnormality indicative of prior infarction was demonstrated on MRI in 20 of the 22 patients. Wall thinning was seen in 20 patients; in six of these, the thinning resulted in aneurysm formation. The other 14 patients had sufficient residual wall thickness to permit measurement of T2 relaxation times and MR signal intensity in the infarcted region. Ten of these 14 patients demonstrated low intensity and shortened T2 of the thinned segments (mean T2 = 28.7 msec) compared to adjacent normal myocardium (mean T2 = 45.4 msec) and to the myocardium of volunteers (mean T2 = 41.3 msec). The percentage of difference in intensity between thinned and normal myocardium was greater on 56-msec-TE images (98.2%) than on 28-msec-TE images (46.1%). In the other four patients, no difference in intensity of the myocardium was perceptible in the thinned region of the myocardial wall. Thus MRI shows regional wall thinning at the site of prior MI. In some patients, the chronic infarct is characterized as decreased spin-echo signal intensity and shortened T2 consistent with replacement of myocardium by fibrous scar.     

MRI of medulloblastoma in adults

Medulloblastoma has variable appearances on MRI in both children and adults. Adults are more likely to have heterogeneous cerebellar hemisphere tumours, and this is thought to be related to the greater prevalence of desmoplastic tumours in adulthood. Few studies have addressed the MRI features of adult medulloblastoma and the specific characteristics of desmoplastic and classic tumours have not been analysed. Our aim was to analyse the imaging characteristics of desmoplastic (DM) and classic (CM) medulloblastomas in adult. We retrospectively studied preoperative MRI of six men and three women, median age 33 years, range 23–53 years, with pathologically proved medulloblastomas. There were six (67%) with DM. The tumour was in the cerebellar hemisphere in eight patients (89%), including the three with CM, one of which was bilateral. All tumours were heterogeneous, giving predominantly low or isointense signal on T1- and isointense signal on T2-weighted images. Cystic or necrotic areas in all patients were particularly visible on T2-weighted images. Contrast enhancement was absent in one DM and varied from slight to intense in eight (three CM), homogeneous in one DM and patchy in seven. All tumours extended to the surface of the cerebellum and two had well-defined margins. MRI does not allow a clear distinction between DM and CM in adults.     

恶性外周神经鞘膜瘤的CT和MRI表现

目的回顾性分析恶性外周神经鞘膜瘤的CT和MRI表现,提高对该病的诊断准确性。方法搜集恶性外周神经鞘膜瘤病人12例,术前均进行了CT或MRI检查。结果CT表现平扫上为等、低密度混合的软组织肿块影,外形不规则,边界清楚(n=9)或模糊(n=3);增强扫描时呈不均性强化,坏死区不强化。MRI表现边界模糊,信号混杂。T1WI序列上多与肌肉等信号(n=11),内示局灶性长T1信号影;T2WI抑脂序列上以略高信号为主,边界清楚(n=2)或模糊(n=10),内示局灶性长T2信号,周围软组织浸润表现为片状高信号;增强扫描时呈不均性强化。结论恶性外周神经鞘膜瘤的CT和MRI表现具有一定的特征性。     

Role of cranial imaging in epileptic status

Introduction

There is paucity of studies evaluating the role of cranial imaging in the management of status epilepticus (SE); therefore this study evaluates the role of imaging in predicting the outcome of SE.

Methods

Consecutive patients with SE were prospectively evaluated. Clinical evaluation, blood counts, serum chemistry and cerebrospinal fluid (CSF) were carried out. Cranial CT scan was performed on a spiral CT and MRI on a 1.5 T scanner. Patients were treated with IV sodium valproate, phenytoin and benzodiazepines as per fixed protocol. Outcome was defined as seizure control at 1 h and mortality. Various clinical and radiological parameters were correlated.

Results

There were 99 patients with SE whose mean age was 35 (1–78) years, 40 females and 17 were below 12 years of age. Fifty six patients had central nervous system (CNS) infections, 15 strokes, 13 metabolic encephalopathy, 5 drug default and in the remaining 10 patients various acute symptomatic causes were present. Cranial imaging was abnormal in 59% patients. CT was abnormal in 21 (47.7%) out of 44 patients whereas MRI was abnormal in 26 (63.4%) out of 41 patients. Both MRI and CT were carried out in 14 patients and 12 revealed abnormalities; 2 had abnormality only on MRI. Imaging revealed cortical lesions in 10, subcortical in 19 and both cortical as well as subcortical in 30 patients. One hour seizure control was achieved in 60, seizures recurred within 24 h in 38 and 27 patients died during hospital stay. Seizure type, duration of SE, seizure control at 1 h and mortality did not correlate with radiological abnormalities.

Conclusion

Cranial imaging reveals structural abnormality in 59% patients with SE and was not related to SE control and mortality.     

Migraine: evaluation by MR

Twenty-four patients clinically diagnosed as having migraine (17 of the classic or common type and seven of the complicated type) were evaluated on a 0.5-T or 0.6-T superconductive MR imaging unit with the objective of detecting associated parenchymal lesions. Thirteen (54%) of the patients had normal MR studies. Eleven (46%) of the patients (seven with classic or common and four with complicated migraine) showed well-defined lesions with prolonged T2 signal intensity. The lesions associated with classic migraine were focal and predominantly distributed in the periventricular white matter, bilateral in four and unilateral in three. In the group with complicated migraine, larger cortical abnormalities similar to infarcts were seen in three patients and multiple bilateral focal white matter lesions were seen in one. Almost all the lesions were evident only on T2-weighted studies; a few exhibited hypointense signal intensity on T1-weighted studies. The focal periventricular white matter lesions were not necessarily associated with neurologic deficits, but the cortical lesions were. Our study indicates that parenchymal changes are frequently associated with migraine and that MR may well be the screening and diagnostic method of choice for their detection and evaluation.     

MRI and MR angiography of vertebral artery dissection

A review of 4,500 angiograms yielded 11 patients with dissection of the vertebral arteries who had MRI and (in 4 patients) MR angiography (MRA) in the acute phase of stroke. One patient with incidental discovery at arteriography of asymptomatic vertebral artery dissection and two patients with acute strokes with MRI and MRA findings consistent with vertebral artery dissection were included. Dissection occurred after neck trauma or chiropractic manipulation in 4 patients and was spontaneous in 10. Dissection involved the extracranial vertebral artery in 9 patients, the extra-intracranial junction in 1, and the intracranial artery in 4. MRI demonstrated infarcts in the brain stem, cerebellum, thalamus or temporo-occipital regions in 7 patients with extra- or extra-intracranial dissections and a solitary lateral medullary infarct in 4 patients (3 with intracranial and 1 with extra-intracranial dissection). In 2 patients no brain abnormality related to vertebral artery dissection was found and in one MRI did not show subarachnoid haemorrhage revealed by CT. Intramural dissecting haematoma appeared as crescentic or rounded high signal on T1-weighted images in 10 patients examined 3–20 days after the onset of symptoms. The abnormal vessel stood out in the low signal cerebrospinal fluid in intracranial dissections, whereas it was more difficult to detect in extracranial dissections because of the intermediate-to-high signal of the normal perivascular structures and slow flow proximal and distal to the dissection. In two patients examined within 36 h of the onset, mural thickening was of intermediate signal intensity on T1-weighted images and high signal on spin-density and T2-weighted images. MRA showed abrupt stenosis in 2 patients and disappearance of flow signal at and distal to the dissection in 5. Follow-up arteriography, MRI or MRA showed findings consistent with occlusion of the dissected vessel in 6 of 8 patients. Received: 27 February 1996 Accepted: 4 June 1996     

MR imaging of the brain in patients with migraine headaches

Forty-one patients with migraine headaches were referred for MR imaging of the brain. Intermediate and T2-weighted images were obtained to determine the frequency of areas of high intensity within the white matter. The average age of these patients was 29.8 years; only five were over 40 years old. Each patient was evaluated in the axial plane with long TR/short and long TE images. Twenty-three patients also had T1-weighted short TR/short TE MR scans; enhancement with gadopentetate dimeglumine was used in three patients. Intracranial abnormalities were seen in only six patients: foci or white matter high intensity on intermediate and T2-weighted images in five and a venous angioma in one. Prior studies have indicated that parenchymal brain abnormalities may be found in up to 46% of patients with migraines. The current study demonstrated parenchymal brain lesions in only 12%. This study suggests that the frequency of foci of high intensity seen on long TR sequences in the migraine patient is much lower than previously reported, especially in patients under 40 years old (5.5% in our series).     

颅脑钙化灶的MR磁敏感成像

目的:探讨磁敏感成像技术(SWI)对显示颅内钙化灶的敏感性,并探讨钙化灶在SWI序列中的信号特点。方法:搜13例颅内钙化患者(共56处钙化灶)均进行CT和MRT1WI、T2WI和SWI扫描。结果:钙化灶在T1WI和T2WI上信号多样,没有特异性;在SWI相位校正图上显示为高信号或以高信号为主的混杂信号;在SWI重建图中显示为低信号。98.21%(55/56)的钙化灶DWI上均能显示,且病灶大小和形态与CT所见一致。颅内生理性和病理性钙化灶在SWI序列上检出率和信号特点的差异无统计学意义;脑实质内和脑室系统内钙化灶在SWI序列上检出率和信号特点的差异无统计意义。结论:SWI序列对颅内钙化灶的显示和检出敏感性高,可弥补常规MRI序列对钙化灶显示的不足。     

非潜水性骨梗死影像学诊断

目的 探讨非潜水性骨梗死的影像学表现。方法 7例患中，平片 CT MRI ECT检查、平片 CT、平片 MRI检查各2例；单纯拍平片1例。结果 7例共累及14骨。早期平片、CT可无异常发现，亦可见病变区密度不均或轻度骨膜反应。MRI示病灶中心T1WI呈等骨髓脂肪信号，边缘呈迂曲的低信号带；该带T2WI可分2层。整个坏死区呈地图样改变。ECT显示为中央放射性缺损，边缘放射性浓聚。晚期平片、CT扫描病灶呈类环形、花边状或条状致密影。MRI、ECT此期表现无特征。结论 对早期病例，MRI是最好的检查手段。晚期病例检查应首选平片和CT。     

成人白血病中枢神经系统并发症的CT与MRI表现

目的 探讨成人白血病中枢神经系统并发症(CNSCL)的CT和MRI表现及其诊断价值.方法 回顾性分析18例经临床及手术病理证实的成人CNSCL的CT和MRI表现,其中急性淋巴细胞白血病7例,急性非淋巴细胞白血病10例,慢性粒单细胞白血病1例.CT平扫11例,其中增强1例;MR平扫16例,其中增强11例.结果 颅内受累14例:(1)颅内出血7例,其中脑内血肿4例,脑内血肿合并微出血1例,微出血2例.脑内血肿均为多发病灶.CT表现为团状高密度影;MRI表现为T1WI低信号或高低混杂信号,T2WI高信号或等高信号伴环状低信号环,病灶呈环形强化或无明显强化.脑微出血在磁敏感加权成像(SWI)上表现为多发斑点状及小条状低信号,其病灶检出率明显优于CT及MRI其他常规序列检查;7例中,伴脑梗死及蛛网膜下腔出血各1例.(2)颅内肿块5例:其中左额部内板下梭形病灶或跨颅板肿块2例,T1WI呈低信号,T2WI呈高低混杂信号,并有明显均匀强化,均见脑膜尾征;鞍区肿块1例,CT示鞍区高密度影,MRI示鞍区T1WI稍低信号,T2WI高信号,有不均匀强化;右侧脑室体旁肿块1例,T1WI、T2WI均呈等信号,有明显均匀强化.左额顶叶壁厚囊性肿块1例,呈环形强化.(3)梗阻性脑积水1例,表现为中脑导水管以上脑室系统扩张.(4)脑膜病变1例,MRI表现为广泛脑膜增厚伴明显均匀强化.椎管内病变4例:其中胸腰椎左侧椎旁软组织肿块2例,侵犯椎管内,伴邻近肋骨骨质破坏1例;椎管内肿块1例,表现为胸椎管后方梭形T1WI等高信号,T2WI等低信号灶,无明显强化;胸髓信号异常1例,表现为胸髓条状T2WI及液体衰减反转恢复(FLAIR)序列高信号影.结论 成人CNSCL影像表现多种多样,CT与MRI对该病的诊断价值相辅相成;白血病患者疑脑内病变者,建议常规使用SWI检查,以尽早发现脑微出血,降低脑内血肿发生的风险.

Abstract：

Objective To evaluate the CT and MRI findings and their diagnostic value of central nervous system complications of leukemia (CNSCL). Methods The CT and MRI findings of 18 adult patients with CNSCL proved by clinical features or pathology were retrospectively analyzed. Among 18 cases,7 were acute lymphocytic leukemia, 10 acute non-lymphocytic leukemia and 1 chronic myelomonocytic leukemia. Eleven cases underwent plain CT scan with one of them also receiving contrast-enhanced CT scan enhancement, 16 cases underwent plain MR scan with 11 of them receiving contrast-enhanced MR scan.Results Intracranial lesions in 14 cases: (1)intracranial hemorrhage was found in 7 cases, including intracerebral hematoma in 4 cases, micro-haemorrhage in 2 cases, and intracerebral hematoma accompanying by multiple intracerebral micro-haemorrhage foci in 1 case. All cases with intracerebral hematoma showed multiple lesions, which demonstrated high-density on CT images, and low or mixed signal on T1 WI, high- or intermediate signal with low-signal rim on T2 WI and ring enhancement or no evident enhancement. Microhaemorrhage manifested as multiple mini-mottling and strip hypointense foci on susceptibility weighted imaging, on which the detection rate of micro-haemorrhage foci was much higher than that on CT and other sequences of MRI. Among the 7 cases, one also had cerebral infarction and one subarachnoid hemorrhage.(2) Intracranial mass was found in 5 cases, among which two appeared as masses under or bestride cranium in the left frontal region with hypointensity on T1 WI, mixed signal on T2WI, strong homogeneous enhancement and dural tail sign;one showed a mass in saddle area, with high density on CT, slightly low signal on T1WI, high signal on T2WI and heterogeneous enhancement; one case displayed a mass near lateral ventricle with iso-intensity on T1 WI and T2WI and strong homogeneous enhancement; and one case manifested as cystic mass in the left fronto-apical lobe, with thick wall and ring enhancement (3)Obstructive hydrocephalus was found in 1 case, manifesting dilation of ventricles above the aquaeductus mesencephali. (4) Meningopathy was found in 1 case, manifesting diffuse thickening of meninges with strong homogeneous enhancement on MRI. Pathological changes of spinal canal was found in 4 cases among which two showed para-spinal mass involving vertebral canal and causing bone destruction of adjacent ribs; one case showed fusiform mass posterior to vertebral canal with high and intermediate signal on T1 WI and low and iso-signal on T2WI without enhancement; one showed zonale leison in thoracic cord with high signal on T2WI and fluid attenuated inversion recovery. Conclusion The radiologic manifestations of adult CNSCL are various and the role of CT and MRI for the diagnosis of CNSCL may complement each other. SWI is suggested as routine examination for patients of leukemia, in whom intracerebral lesions were suspected in order to find micro-haemorrhage as early as possible and reduce the risk of intracerebral hematoma occurrence.     

子宫腺肌症的MRI研究

目的　探讨MRI对子宫腺肌症的诊断价值及其表现特征。方法　对 46例疑子宫腺肌症的患者分别行B超和MRTSE序列T1WI、T2 WI和IR序列T1WI扫描 ,同时行增强检查 ,并与术后病理进行对照分析。结果　以手术病理为标准 ,MRI诊断子宫腺肌症的特异性、灵敏性和准确性分别为 10 0 %、94.74%和 97.14 % ,均明显较B超高。子宫有不同程度的增大 ,轮廓光滑 ,有时可见子宫分层结构变形。病灶表现为结合带弥漫性 /局限性增厚或外肌层结合带样信号灶 ,T2 WI可混杂有局灶性高信号。当有出血时 ,T1WI也可混杂局灶性高信号灶。增强后病灶呈结合带样强化。结论　MRI对子宫腺肌症的定性、定位具有很高的诊断价值 ,可作为B超检查的重要补充手段     

MRI与CT在颅底脊索瘤诊断中的价值

目的：分析发生在颅底部脊索瘤的MRI和CT表现，以探讨MRI和CT在颅底部脊索瘤诊断中的价值。方法：搜集22例证实的病例，其中男性13例，女性9例，最大年龄67岁，最小年龄13岁，平均年龄42岁。22例均行MRI平扫和增强检查，其中7例进行了GT检查。结果：肿瘤发病部位主要位于斜坡及其周围区域，其中斜坡15例、鞍内2例、鞍旁1例、颈静脉孔区2例、蝶窦1例、鼻咽部1例。肿瘤的形态以不规则形最多16例，圆形4例，椭圆形2例。病灶边界清楚15例，边缘模糊7例。MRI表现T1WI呈低、等、高混杂信号，T2WI以高、低信号为主，其中18例呈混杂信号，4例表现为信号均匀。增强后病灶呈不均匀轻到中度强化，强化信号不均匀。CT病灶呈不均匀等或稍高密度肿块，均见不同程度的骨质破坏。结论：MRI由于有多轴面成像的优势，可以准确显示颅底脊索瘤的大小、形态、边界及其信号特点。CT在显示病灶的骨质破环、残存骨质方面较MRI具有优势。因此，MRI和CT相结合在颅底脊索瘤的诊断中具有很大的价值。     

Charcot关节的影像表现

目的 探讨Charcot关节的MRI表现，评价X线片、CT及MRI对Charcot关节的诊断价值。方法 对8例Charcot关节作X线、CT及MR检查，其中6例患有脊髓空洞症，1例为胸髓损伤截瘫患者，1例为糖尿病患者，所有8例均有患肢的痛觉减退或消失。结果 (1)Charcot关节表现为增生和吸收2型。(2)X线及CT特点：3例增生型关节骨质增生硬化、骨赘形成，关节周围软组织肿胀，内见大量块状骨化影；5例吸收型关节以骨质破坏吸收、碎裂为主，骨端消失，其中3例残端平齐如手术切除，周围软组织肿胀，内见多个小而锐利的骨化影。8例中有3例伴有关节半脱位。(3)主要MRI特点：8例均清楚显示关节周围软组织块影结构，7例分为3层：由内向外为关节囊内积液、关节囊壁及囊壁外其余软组织块影，1例关节囊壁与其外软组织块影分界不清，表现为2层结构。关节囊壁不均匀增厚、松弛及拉长，在关节周围、骨干旁或肌间隙内呈伪足状伸延，T1WI呈稍低信号，T2WI呈稍高信号，注射钆喷替酸葡甲胺(Gd—DTPA)后明显强化，其强化程度常高于外周的软组织块影。关节周围软组织块影的3层结构及关节囊的改变较具特点。结论 X线片是Charcot关节的首选诊断手段，MRI在Charcot关节的诊断及鉴别诊断方面是X线片重要的补充手段。