CT and MRI in severe hypophosphataemia with central nervous system involvement

We report a 38-year-old woman with extreme hypophosphataemia in whom CT and MRI disclosed bilateral lesions within the basal ganglia, thalamus and occipital lobes. After adequate substitution of phosphate the lesions grossly resolved and the patient recovered. This case is the first to demonstrate that profound changes of serum phosphate may be associated with reversible brain lesions. Received: 27 March 1999/Accepted: 16 June 1999     

Progressive multifocal leukoencephalopathy in AIDS: initial and follow-up CT and MRI

We sought to determine the value of follow-up CT and MRI in patients with acquired immunodeficiency syndrome (AIDS) and progressive multifocal leukoencephalopathy (PML). We reviewed 50 CT and 19 MRI examinations performed in 21 biopsy- or autopsy-proven cases of PML; 17 patients had follow-up examinations (mean time 5.9 weeks). The radiological examinations were correlated with pathological findings at autopsy. On initial imaging studies, 73 lesions were found. On follow-up, the most striking feature was rapid progression in both size and number of the lesions (from a mean of 3.2 to 6.9 per patient). One third of the patients showed increasing mass effect. A central area suggesting necrosis, of variable size, was found in 12/16 patients. Autopsy revealed macroscopic necrotic changes in the lesions in 11/16 patients. Received: 30 May 1996 Accepted: 14 October 1996     

颅内原发性中枢神经系统淋巴瘤的MRI表现

目的研究颅内原发性中枢神经系统淋巴瘤（PCNSL）的MR／表现特点。方法回顾性分析8例经手术病理证实的原发性中枢神经系统淋巴瘤的MR／表现。结果8例均为弥漫大B细胞型非霍奇金淋巴瘤。3例为单发,5例为多发,共13个病灶,其中大脑半球8个,基底节区4个,右侧背侧丘脑及基底节区1个。8例病变均表现为局灶性肿块,T1WI呈稍低或等信号;T2WI呈等或稍高信号。增强扫描7例呈明显均匀强化,1例轻度强化。6例瘤周重度水肿,2例瘤周中度水肿。结论原发性中枢神经系统淋巴瘤较为罕见,MRI是诊断该病的重要的无创性检查方法。颅内PCNSL影像学表现多样,但具有一定特征。     

女性生殖系统淋巴瘤CT及MRI表现

目的：探讨女性生殖系统淋巴瘤的计算机体层成像（computed tomography,CT）及磁共振成像（magnetic resonanceimaging,MRI）特征,以期提高治疗前的诊断准确度。方法：回顾并分析13例女性生殖系统淋巴瘤患者的CT及MRI资料,其中7例行MRI平扫+增强扫描,6例行CT平扫+增强扫描。结果：13例患者中,弥漫性大B细胞淋巴瘤12例（92.3%）,滤泡性淋巴瘤1例（7.7%）,其中以卵巢受累最多见（6/13,46.2%）,其次是宫颈（5/13,38.5%）和子宫体（2/13,15.4%）。共检查发现14个病灶（MRI和CT各7个）,其中1例卵巢淋巴瘤为双侧受累。所有病灶均为实性肿块,64.3%(9/14)的病灶信号或密度相对均质;35.7%(5/14)的病灶边缘可见小囊变区,均见于卵巢淋巴瘤。行CT扫描的7个肿块中,平扫均表现为等密度肿块,内部未见出血及钙化;行MRI扫描的7个肿块中,表现为T1加权成像（T1-weighted imaging,T1WI）等或稍低信号,T2加权成像（T2-weighted imaging,T2WI）以中等信号为主（6/7...     

Malignant lymphoma of the cranial vault in an HIV-positive patient: imaging findings

We describe the CT and MR imaging findings in an HIV-positive patient with malignant non-Hodgkin's lymphoma of the cranial vault, a rare site for lymphoma involvement. Autopsy revealed lymphomatous bone lesions, lymphoma in the epidural space, and a large necrotic lymphoma in the soft tissue of the skull.     

原发性中枢神经系统淋巴瘤的磁共振成像表现

目的探讨原发性中枢神经系统淋巴瘤（PCNSL）的磁共振成像（MRI）特征及鉴别诊断。方法回顾性分析15例经手术病理证实的PCNSL的MRI表现。结果病理检查均为B细胞来源的弥漫性大B细胞性淋巴瘤。15例PCNSL19个病灶,单发13例（87％）,多发2例（13％）共6个病灶。病灶常位于脑表浅部位和近中线部位,T1wI呈等或稍低信号,T2WI及液体衰减反转恢复序列（FLAIR）呈等或稍高信号,弥散加权成像（DWI）呈高信号。所有病灶均明显强化,增强后病灶大多呈均匀实质团块状或结节状强化,典型的可出现“尖角征”、“握拳征”,3例可见小囊变,呈“硬环征”。结论PCNSL的MRI表现具有一定的特征性,术前MRI检查有助于诊断及鉴别诊断,结合患者影像学及临床资料,术前可作出明确诊断。     

Intracranial tuberculosis in AIDS: CT and MRI findings

Summary CT and MRI findings in 35 patients with the acquired immune deficiency syndrome (AIDS) and proven intracranial tuberculosis (TB) are presented. Over 90% of the patients were intravenous drug abusers and in two-thrids TB was the first manifestation of AIDS. CT was normal in one quarter, the most frequent findings being hydrocephalus (51%) and meningeal enhancement (41%), commonly seen together (31.5%). Meningeal enhancement was seen in 48% of the CT studies with intravenous contrast medium and in 3 cases studied with MRI and iv gadolinium DPTA, in 2 of which CT was negative. Parenchymal involvement was found in 37% of cases; MRI was more sensitive than CT for its detection. One quarter of the patients had ischaemic lesions, mainly in the basal ganglia. We confirm the usefulness of CT and the superiority of MRI in the diagnosis of intracranial TB and in differential diagnosis from other conditions likely to be found in these patients.     

Medulloblastoma in children: CT and MRI findings

Our purpose was to determine whether medulloblastoma (MB) shows specific neuroradiological features which may be employed in differential diagnosis from other common posterior cranial fossa tumours in childhood. Preoperative MRI was performed on 20 children with MB, and preoperative CT in 17 of them. All underwent surgery and histopathological diagnosis. There was a constant relationship between high density on CT and low signal on T1-weighted images. Signal behaviour on T2-weighted images and the degree of contrast enhancement were more variable. Most tumours arose in the midline, from the cerebellar vermis, involving the fourth ventricle, but hemisphere and extra-axial neoplasms were also seen. The combination of high density on CT and low signal on T1-weighted images is highly suggestive of MB and may assist preoperative differential diagnosis from other posterior cranial fossa tumours.     

Primary central nervous system immunocytoma: MRI and spectroscopy

We report on a young woman with a primary cerebral immunocytoma. Most primary cerebral nervous system lymphomas (PCNSL) are highly malignant undifferentiated B-cell tumours, there are few data on the clinical course, MRI and spectroscopy findings of this rare PCNSL subtype. MRI revealed a radially enhancing tumour with mild perifocal oedema. MR spectroscopy indicated low cell turnover. Slow clinical progression, no significant changes with treatment, and imaging findings were consistent with a low-grade malignant tumour. Received: 21 January 2000/Accepted: 15 February 2000     

Primary malignant lymphoma of the maxillary sinus: CT and MRI

We reviewed the CT and MRI of seven patients with primary malignant lymphoma of the maxillary sinus to find if there are characteristic imaging findings suggestive of the disease. The images were analysed for appearance, size, signal, internal characteristics, extent of tumour, bone change and lymph node enlargement. In two patients, the tumour first presented with mucosal thickening. In the remaining five, the tumours were an expansile mass 4–6 cm in diameter at the time of detection. Although it was difficult to distinguish tumour from mucosa or obstructed fluid on CT, T2-weighted MRI enabled us to separate tumour from normal mucosa or fluid. In two patients, the tumours were heterogeneous. Calcification and haemorrhage were observed in one patient. Periantral soft-tissue infiltration was always present, even when tumour appeared as slight mucosal thickening. Posterior extension was seen in all patients. Permeative and lytic bone destruction accompanied most cases of periantral soft-tissue infiltration; mixed destruction and sclerosis was also observed. Mucosal thickening with periantral soft-tissue infiltration may suggest malignant lymphoma of the maxillary sinus in its early form. Various types of bone change may accompany the periantral soft-tissue infiltration. Received: 25 January 1999 Accepted: 21 July 1999     

原发性中枢神经系统淋巴瘤的MRI诊断

目的 研究原发性中枢神经系统淋巴瘤(PCNSL)的MRI表现特点,提高对该病的诊断与鉴别诊断率.方法 回顾分析了12例经病理证实的原发性中枢神经系统淋巴瘤的MRI表现.结果 病灶T1WI多呈略低或等信号,T2WI呈等或略高信号;增强扫描多呈明显均匀强化,极少数呈环形强化,肿瘤坏死囊变少见,未见出血、钙化;瘤周水肿相对较轻,占位效应轻.结论 原发性中枢神经系统淋巴瘤MRI表现具有一定特征性,可做出较准确的诊断.     

获得性免疫缺陷综合征的脑部MRI表现

本文分析１０例获得性免疫缺陷综合（ＡＩＤＳ）的脑部ＭＲＩ表现。将脑部异常分成５种类型：脑萎缩（８例）、白质病变（６例）、灰质病变（１例）、肿块（５例）和出血（２例）。最常见类型是前２者。ＭＲＩ诊断ＡＩＤＳ的单一致病病原体十分困难，但结合脑萎缩与对称性脑室周围或弥漫性白质病变可提示人类免疫缺陷病毒（ＨＩＶ）脑炎。     

Ependymomas of the posterior cranial fossa: CT and MRI findings

We studied nine children with posterior cranial fossa ependymomas to identify specific neuroradiological features. Patients were studied preoperatively with CT and MRI; T1-, T2-and proton-density (PD)-weighted images were obtained. All children underwent surgery and a definite histopathological diagnosis was made. All the tumours grew into the fourth ventricle and caused dilatation of its upper part, which resembled a cap. All but one were separated from the vermis by a cleavage plane. In eight cases there was desmoplastic development through the foramina of the fourth ventricle, and five were heterogeneous due to necrosis and cystic change; one had a haemorrhagic area. In most cases the solid portion was isointense with grey matter on T1-weighted images, hyperintense on PD weighting, and isointense on T2-weighted images. On CT the tumour was isodense in six cases and calcification was detected in four. The presence of both desmoplastic development and a tumour/vermis cleavage plane in a posterior cranial fossa tumour isodense on CT is highly suggestive of ependymoma.     

Cryptococcus meningoencephalitis in AIDS: parenchymal and meningeal forms

CT and MRI in one case of Cryptococcus neoformans infection showed contrast-enhancing parenchymal lesions resembling granulomata or abscesses. After an initial phase without contrast enhancement, the full extent of the lesions was visible within 2 weeks of presentation. The enhancing masses were assumed to represent intracerebral cryptococcomas. Despite evidence of massive meningeal infection on cerebrospinal fluid (CSF) examination, no radiological signs of meningitis, invasion of the Virchow-Robin spaces or ventriculitis could be demonstrated. With antimycotic treatment the contrast enhancement disappeared and cystic, partly calcified lesions remained. Recurrence of meningeal infection without radiological correlates was apparent in this stage. In a second case of proven cryptococcus meningitis, dilation of Virchow-Robin spaces or cysts in the adjacent parenchyma were the main abnormalities on MRI. Enhancing masses were not detected. These cases may represent two different reactions of the immunocompromised hosts to infection with C. neoformans: widening of the perivascular spaces as a correlate of the more typical meningeal infection and enhancing parenchymal lesions as a sign of further invasion from the CSF spaces. Enhancement of cryptococcomas, indicating an inflammatory response in the surrounding brain, is not typical in patients with impairment of immune function. Received: 11 March 1998 Accepted: 19 June 1998     

Reversible MRI and CT findings in uremic encephalopathy

Summary In this 35-year-old woman with chronic glomerulonephritis and uremic encephalopathy, the basal ganglia bilaterally, internal capsules and periventricular white matter showed hypodensity on CT, low signal intensity on T1-weighted MRI and high signal intensity on T2-weighted MRI. Following a series of dialyses, her clinical symptoms and blood chemistry improved. The CT and MRI returned to normal. These reversible abnormalities may be caused by reversible ischemic change, but disorders of cerebral metabolism and uremic toxins may contribute.     

Isodense subdural haematomas on CT: MRI findings

Summary MRI findings are described in two patients with subdural haematomas isodense on CT. In one patient, admitted 6 weeks after trauma, a chronic subdural haematoma showed extreme hypointensity on T2-weighted images, suggesting acute trauma, and therefore acute rebleeding. In the second patient with severe anaemia, an acute subdural haematoma was hyperintense on T2-weighted images, suggesting chronic trauma; this may be explained by the low haematocrit and a possible mixture of blood with cerebrospinal fluid. The MRI features of subdural haematomas and hygromas have to be kept in mind, in order not to misjudge the age of the haematoma.     

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.     

中枢神经系统肠源性囊肿的MRI表现

目的:探讨中枢神经系统肠源性囊肿的MRI表现.方法:搜集经手术及病理最终确诊的23例肠源性囊肿患者并分析其MRI表现,所有患者均经MRI平扫,其中10例行MRI增强扫描,4例行DWI扫描.结果:23例肠源性囊肿患者中,3例发生在颅内,其中2例发生在左侧中颅窝,1例发生在桥前池,其余20例发生在椎管并且全部位于髓外硬膜下,其中颈段10例,胸段8例,腰段2例.MRI平扫大部分病灶T1WI呈等低信号,T2 WI呈高信号,部分病灶信号混杂;9例增强扫描囊液及囊壁均未见明确强化,1例见边缘强化;部分病例可见特征性“脊髓嵌入征”表现;DWI均未见明显扩散受限;2例伴脊椎发育异常.结论:肠源性囊肿的形态及MRI信号特点具有一定特征,结合临床症状、伴发体征有助于早期诊断.     

原发性脑淋巴瘤的CT及MRI诊断

目的探讨原发性脑淋巴瘤的CT及MRI影像学特征。方法对20例经手术病理证实的脑淋巴瘤患者的CT及MRI影像学表现进行回顾性分析。结果20例脑淋巴瘤患者17例单发，3例多发，共有24个病灶。其中，CT及MRI图像有以下特点：a）瘤灶多为单发，幕上多见，多为圆形或不规则形；b）CT平扫多呈等或略高密度，无钙化，MR T1WI呈略低或等信号，T2WI呈等或略高信号，瘤周水肿及占位效应相对较轻；c）CT及MRI增强扫描病灶多呈均匀明显强化，亦可不均匀呈环形或花瓣样强化。结论脑原发性淋巴瘤影像表现缺少特征性，确诊主要依靠病理检查。     

Disseminated intracerebral alveolar echinococcosis: CT and MRI

Cerebral alveolar echinococcosis is rare and has a poor prognosis. We report an unusual case presenting with disseminated intracranial lesions secondary to primary hepatic infection. Received: 2 May 1996 Accepted: 23 August 1996