CT呈高密度的垂体Rathke囊肿的MRI影像学特征

目的探讨CT高密度垂体Rathke囊肿的MRI影像学特征。方法回顾性分析2013年1月至2018年1月手术治疗的1 104例垂体病变的临床资料,其中Rathke囊肿186例,而术后病理证实为垂体Rathke囊肿、术前CT为高密度的Rathke囊肿9例。结果 9例CT呈高密度的垂体Rathke囊肿中,垂体柄上型5例,垂体柄下型4例;MRI T1像呈等信号6例、高信号3例,T2像呈等信号5例、低信号2例、高信号2例;垂体柄上型囊肿囊壁未见强化,垂体柄下型囊肿周围呈现明显的环形强化征。结论 CT呈高密度的垂体Rathke囊肿可分为垂体柄上型和垂体柄下型,以前者多见;该类囊肿MRI平扫缺乏恒定的影像学信号,动态增强影像显示垂体柄上型囊壁无明显增强,垂体下型囊壁呈现明显的环形强化征。     

Trigeminal neurinoma presenting with intratumoral hemorrhage: report of two cases.

We report 2 cases of trigeminal neurinoma presenting with spontaneous intratumoral hemorrhage. There are only 2 similar cases reported in the literature. Presenting symptoms were headache, diplopia, disturbed consciousness and trigeminal disturbance with sudden onset. CT scan showed a typical fluid-fluid level within low-density mass in the cerebellopontine angle in one case. On MRI, one case showed a typical fluid-fluid level on T2-weighted image and another one had mixed signal intensities including hyper- and hypointensities on both T1- and T2-weighted images. Histologically, increased vascularity, consisting of dilated and thin-walled vessels presenting telangiectatic or cavernous angiomatous appearances were observed in the specimens in both cases. The size of these tumors was about 3 cm each in diameter. Risk factors for hemorrhage appear to be large tumor size and increased vascularity.     

A case of cystic metastatic intracranial amelanotic melanoma--analysis of findings in CT and MRI

A case of cystic intracranial metastatic amelanotic melanoma is presented. As far as we know, cyst formation in intracranial melanoma is rare, and only 15 cases of intracranial amelanotic melanoma have been reported until now. A 63-year-old man was admitted with headache and progressive visual disturbance. CT scan revealed a large low-density mass with ring-like enhancement in the left frontal lobe. Both T 1-and T 2-weighted MRI images revealed hyperintensity. A left frontotemporal craniotomy was performed. A yellowish mass was observed in the frontal lobe. The content of the cyst consisted of old hematoma, xanthochromic fluid and necrotic tissue, was evacuated and the cyst wall was totally resected. No abnormal pigmentation was noted in the cyst wall and surrounding brain tissue. The histological examination revealed amelanotic melanoma. Primary lesion was found on the left thigh later and resected. The patient died of further intracranial metastasis with repeated hemorrhage 5 months after the admission. Both CT and MRI findings of our case is atypical as an intracranial malignant melanoma. However, these are compatible with those of intracerebral hemorrhage in subacute stage. It is suggested that melanoma may make the diagnosis difficult when tumor hemorrhage modifies the images of CT or MRI.     

Adrenoleukodystrophy. Value of contrast-enhanced MR imaging

In its early stage adrenoleukodystrophy (ALD) is characterized by hypodensity at CT and signal abnormalities at RMI (low-intensity signal on T1-weighted sequences, high-intensity signal on T2-weighted sequences) in the white matter of the parieto-occipital region and the splenium of the corpus callosum. These CT and RMI abnormalities are suggestive of ALD in children with progressive alteration of the superior brain functions, but they are not specific of the disease. The authors present two cases of ALD and underline the almost pathognomonic value of contrast-enhanced ribbons found at the periphery of low-intensity signal plaques after gadolinium injection. These areas of blood-barrier disruption on a background of inflammation and active demyelination appear, on T2-weighted sequences, as ribbons of low-intensity signal within plaques of high-intensity signal. MRI is also superior to CT in detecting abnormalities located in the posterior fossa, notably lesions of the auditory fibres.     

Prognosis and MRI after ischemic stroke of the basal ganglia.

The clinical courses and long-term prognoses in 16 young patients with infarctions of the basal ganglia were evaluated and the recent magnetic resonance imaging findings in 9 of them were examined. Only 5 of 14 patients (35%) had motor sequelae, 4 had hemiparesis, and 1 had gait disturbance. Secondary dystonia occurred in 1 patient. Magnetic resonance imaging disclosed a circumscribed lesion in the basal ganglia, as reflected by T2 high- and T1 low-intensity signals, in all patients. The abnormal region on T2-weighted images usually was more extensive than that observed on T1-weighted ones. The hemiplegic patients each had an area of abnormal intensity in the internal capsule or corona radiata with relatively high signals on the T2- and proton-density-weighted images. Mild to moderate asymmetric atrophy of the midbrain on the side ipsilateral to the stroke lesion was observed in 8 of 9 patients. The mechanism involved may be remote transsynaptic neuronal death of the substantia nigra, as well as Wallerian degeneration of the pyramidal tract.     

Intrasellar dermoid cyst mimicking pituitary apoplexy: A case report and review of the literature

Intrasellar dermoid cysts are extremely unusual lesions, with only four cases reported to date, and have not been previously reported in association with sudden-onset symptoms. Here, we present the case of an intrasellar dermoid cyst with sudden-onset symptoms mimicking pituitary apoplexy in an elderly woman. A 69 year-old woman presented with sudden onset of headache, dizziness, and decreased visual acuity. Magnetic resonance imaging of the sellar region showed an intrasellar lesion, which showed mixed hyper- and hypointense signal on T1-weighted and T2-weighted images and enhanced peripherally. Endocrine workup showed pituitary hormones within normal levels. According to these findings, the initial diagnosis of nonsecreting pituitary macroadenoma apoplexy was made. Intraoperatively, a large amount of whitish-yellow purulent material was found in the mass and the lesion was partially removed, owing to tight adhesion between remanent mass and surrounding neurovascular structures. Pathology showed a dermoid cyst with abundant neutrophil infiltrations.     

Syrinx formation secondary to cervical epidural abscess]

We report a patient with syrinx formation secondary to cervical epidural abscess, cervical spondylitis, cervical discitis and meningitis. A 53-year-old woman developed sudden fever, headache and neck pain. On admission, neurological evaluation showed limitation of cervical motion, meningeal irritation, and exaggerated muscle stretch reflexes in all four extremities. Cerebrospinal fluid cell count was 832/mm3 and protein was 771 mg/dl. Bacterial culture of the cerebrospinal fluid showed Staphylococcus aureus. A cervical MRI scan with Gd-enhancement revealed focal high intensity signal in the T2-weighted and FLAIR images, at the anterior meninges of the C3-8 segments, the vertebral bodies of C5-6 and the intervertebral disks of C5-6 segment. Her diagnosis was cervical epidural abscess, cervical spondylitis, cervical discitis and meningitis. Antibiotics and steroids improved her symptoms. Six weeks after the onset of symptoms, a cervical MRI scan showed narrowing and synarthrosis in the intervertebral space between C5 and C6. MRI and myelo CT scans demonstrated a newly-formed syrinx from C3-C 7. This was an interesting case of syrinx formation secondary to cervical epidural abscess.     

吸食海洛因致海绵状白质脑病的CT及MRI诊断

目的评价海洛因中毒所致的海绵状白质脑病的CT、MRI表现及诊断价值.方法搜集6例海洛因海绵状白质脑病的CT及MRI资料,全部患者均进行MRI检查,检查序列包括T1WI、T2WI、FLAIR序列,其中2例同时行颅脑CT扫描. 结果全部患者MRI显示对称性双侧小脑半球、大脑半球后部、内囊后肢、胼胝体压部、脑干等皮质下白质为主的多发性大片状长T1、长T2信号,加强后病灶无强化;2例行头颅CT检查显示两大脑半球皮质下白质、基底节及两侧小脑呈对称性广泛低密度灶,无占位效应.结论海洛因中毒所致的海绵状白质脑病具有特征性的MRI表现,MRI对本病的诊断具有重要价值.     

垂体脓肿的诊断与治疗（附9例临床分析）

目的探讨垂体脓肿的临床特点和治疗方法。方法回顾性分析9例垂体脓肿患者的临床表现、影像学特征、诊断和治疗,并结合文献进行分析。结果9例患者中有8例经鼻蝶入路手术,1例行大脑开颅手术。视功能改善77.8%（7/9）,头痛缓解83.3%（5/6）,垂体功能低下改善25%（1/4）,尿崩症缓解33.3%（1/3）。结论垂体脓肿的发生有增多趋势;当患者头痛、视力视野障碍、垂体功能低下,尤其有尿崩的出现,结合影像学检查,鞍区磁共振及增强示类圆形囊状占位性病变,等或长T1,长T2,囊壁呈环形强化（＂鸭梨＂征）等,应考虑垂体脓肿的诊断。诊断一旦确定,应尽早行手术治疗,入路以经蝶为首选;术后予抗感染、补充激素及对症等治疗。     

起源于脑干内神经纤维的神经鞘瘤

目的总结起源于脑干内神经纤维的神经鞘瘤的临床特点及治疗经验。方法回顾性分析12例起源于脑干内神经纤维的神经鞘瘤的临床资料。头部CT表现为低或混杂密度病变。MRI表现T1加权像为等或低信号,T2加权像为高、低或混杂信号,静脉注射GD-DTPA后,可见明显强化或肿瘤结节样强化。均行手术治疗,根据肿瘤位置选择手术入路,采用远外侧入路6例,后正中入路5例,额颞入路1例。手术切除尽量在肿瘤与周围脑组织分界的界面内进行;如果肿瘤与周围界面不清,或位于重要功能区如延髓,为保证术后病人生存质量,可残留部分肿瘤囊壁。结果肿瘤全切除5例,近全切除7例。病理诊断均为神经鞘瘤。随访2～137个月,平均82.3个月。恢复日常生活及工作10例,生活恢复自理1例,死亡1例。结论起源于脑干内神经纤维的神经鞘瘤术前难以确诊。首选手术治疗,但不易达到肿瘤全切除。即使残留部分肿瘤,多数病人仍可获得较高的生存质量。     

Atypical CT and MRI aspects of an epidermoid cyst

We report a case of an unusual epidermoid cyst (EC) of the cerebellopontine angle that appeared hyperdense on computed tomography (CT) scanning, hyperintense on T1-weighted MR images and hypointense on T2-weighted magnetic resonance (MR) images. Diffusion-weighted imaging showed a hypointense lesion. We discuss imaging characteristics of ECs, explain the atypical findings in our case and confirm that the signal seen on diffusion-weighted images in the EC is related to a T2 effect.     

Serial positron emission tomography (PET) in gliomatosis cerebri treated with radiotherapy: a case report

Results of serial positron emission tomography (PET) in a biopsy-proven case of gliomatosis cerebri (GC) are reported. Computed tomography (CT) with and without contrast failed to detect focal abnormalities, but magnetic resonance (MR) revealed iso-intensity or low-intensity lesions in T1-weighted images and high-intensity lesions in T2-weighted images. Lesions were seen in the left thalamus, right temporal lobe and claustrum, and pons. Radiotherapy remarkably improved clinical and imaging findings. Both before and shortly after radiotherapy, 11C-methionine PET images showed hypermetabolism while 15O-water PET images showed a marked increase in cerebral blood flow in GC lesions. However, 6 months later PET images had remarkably improved, appearing nearly normal.     

Laminar cortical necrosis in adrenal crisis: sequential changes on MRI

We describe the serial magnetic resonance imaging (MRI) findings in a six-year-old girl with congenital adrenal hyperplasia, who presented with seizures and unconsciousness during a hypoadrenal crisis. Initial neuroimaging revealed the presence of brain edema with high signal changes in the fronto-parietal cortex on diffusion-weighted MRI. The brain edema worsened four days into admission, and by day 14 low-density areas were seen over the frontal lobes bilaterally using computed tomography (CT). Follow-up MRI at between one and two months of admission revealed extensive white matter lesions with high intensity on T2-weighted images (T2WI) and fluid-attenuated inversion recovery (FLAIR) images, which extended into deep cortical layers. Additionally, linear lesions with high signal change on T1-weighted imaging developed in the superficial cortical layers, with frontal predominance. This layer appeared isointense on T2WI and high intensity on FLAIR images, suggesting laminar cortical necrosis. Two months later, linear, cavitary lesions appeared in the middle cortical layers between the aforementioned superficial laminar abnormality and deep cortex/white matter lesions. The high-intensity signals in the deep cortical layers remained contiguous with the white matter lesions. This unique type of multi-layered cortical lesion may have resulted from a complex combination of hypoglycemia and hypoxia/ischemia in the setting of adrenal insufficiency.     

3.0T MRI多动态增强扫描在垂体微腺瘤检出中的应用

目的探讨3.0T MRI多动态增强扫描在垂体微腺瘤检出中的应用价值。方法使用3.0T MRI对50例垂体微腺瘤患者进行平扫、多动态增强扫描及延迟扫描。结果垂体微腺瘤平扫多只能看到垂体形态的轻微改变,T2WI有时可见到稍长T2信号,多数病灶信号改变不明显。多动态增强扫描增强早期,肿瘤强化程度明显低于正常垂体实质,肿瘤呈稍低信号,境界清楚;中晚期及延时期,肿瘤信号逐渐缓慢增高,部分病灶延时信号高于正常垂体。结论 3.0T MRI多动态增强扫描垂体微腺瘤检出信号具有特征性,可作为临床垂体微腺瘤排查首选。     

An MR image of spinal cord sarcoidosis

Abstract

We present a case of spinal cord sarcoidosis with a unique magnetic resonance imaging (MRI) finding. MRI of the cervical spine revealed an unusual lesion of low signal intensity on T2-weighted image at the core of the lesion surrounded by high signal intensity. Tl-weighted gadolinium enhanced image showed a high signal at the core lesion. Low signal intensity on T2-weighted image in the case was suggested to be due to hemosiderin deposition. Steroid therapy dramatically improved clinical symptoms with a marked reduction of peripheral T2 high intensity area and the core lesion size detected by gadolinium enhancement. [Neurol Res 1999; 21: 755-757]     

Tophaceous gout of the lumbar spine mimicking infectious spondylodiscitis and epidural abscess: MR imaging findings.

We report a case of surgically proven tophaceous gout of the lumbar spine at the L5-S1 level that mimicked infectious spondylodiscitis and epidural abscess on magnetic resonance (MR) images in a 65-year-old woman. The spinal tophi were hypointense on T1-weighted images; focally and strongly hyperintense on T2-weighted images; and heterogeneously, marginally enhancing on contrast-enhanced T1-weighted images. The aim of this report is to emphasize the importance of considering this disease entity in the differential diagnosis of an epidural mass in a patient with chronic back pain.     

Pyogenic abscess from Providencia stuartii mimicking necrotic tumour at perfusion-weighted imaging

The purpose of this case report is to increase the knowledge about magnetic resonance spectrum of pyogenic abscesses of the brain. A 74-year-old woman presented with a left frontal lobe cystic mass, developed in the site of post-traumatic contusions after surgical evacuation of a subdural hematoma. MR imaging showed an ipsilateral mass lesion with a thin, regular rim of T1 high-intensity signal, T2 low-intensity signal, and gadolinium-enhancement. Diffusion-weighted imaging with measure of apparent diffusion coefficient value showed inhomogenous diffusion restriction in the lesion core. Perfusion-weighted imaging (PWI) demonstrated high relative cerebral blood volume (rCBV) in both the lesion wall and perilesional area, with a maximal rCBV ratio (rCBV of the lesion/rCBV of the normal contralateral white matter) of 5.65 and 0.58, respectively. As a result, surgery and pathology showed a pyogenic abscess. Cultures grew were Providencia stuartii species. In conclusion, a pyogenic brain abscess from P. stuartii may show high rCBV at PWI, thus mimicking a necrotic tumour.     

Giant cell polymyositis associated with myasthenia gravis and thymoma

We report a case of a 40-year-old woman who developed generalized muscle weakness over a period of 2 months. Physical examination revealed palpable masses in her arms and hands. Serum creatine kinase levels were elevated. Electromyography showed myopathic changes and 3 Hz repetitive nerve stimulation revealed a decremental pattern on repetitive nerve stimulation. Muscle MRI demonstrated increased signal intensity in the biceps brachii on T1-weighted images. Chest CT scan showed a mediastinal mass suggestive of thymoma. Muscle biopsy revealed giant cell polymyositis. The patient was treated with cholinesterase inhibitors and corticosteroids with improvement of strength, and subsequently underwent thymectomy followed by radiotherapy.     

Repeated hyperglycemic hemichorea in a patient with venous angioma in the putamen]

We report a case of an 81-year-old diabetic woman who had three episodes of choreic involuntary movement in the left extremities. Brain CT revealed faintly increased density in the right putamen. On MRI performed 28 days after onset of the left hemichorea, the right putamen showed increased signal intensity on T1-weighted images and the so-called "medusa-like appearance" of medullary venous drainage into the thalamostriate vein on enhanced T1-weighted images. These findings indicated petechial hemorrhage of the right putamen from a venous angioma. We hypothesize that this hemorrhagic change due to a venous malformation in the basal ganglia may induce involuntary movements in diabetic patients during severe hyperglycemia.     

Intraventricular and Subarachnoid Fat after Spinal Injury

The authors report an extremely rare case with intraventricular and subarachnoid fat developed after trauma to spine and soft tissue in a 54-year-old male. The initial computed tomography (CT) showed multiple low attenuation lesions, which were thought to be pneumocephalus. Cerebral magnetic resonance imaging (MRI) showed lesions with high signal intensity on T1-weighted magnetic resonance images and high signal intensity on T2-weighted images, indicating fat globules within the CSF. In this report, the clinical presentation, radiological findings, and a review of the literature are presented.