椎管内神经纤维瘤的MRI诊断

目的:探讨椎管内神经纤维瘤的MR特征。方法:回顾性分析17例19个经手术病理证实且资料完整的椎管内神经纤维瘤MR表现。结果:19个肿瘤中15个为孤立的神经纤维瘤,MR图像上边界清楚;4个丛状神经纤维瘤,MR图像上整个或部分边界模糊。全部肿瘤T1WI为等-稍高或稍低信号,T2WI为多样的高信号,17个为不均匀的T2加权高信号,其中12个显示中央低信号,周围高信号的“靶征”。增强扫描,呈多样的强化,其中11个显示中央强化。结论:T1WI等-稍高或稍低信号,T2WI多样的高信号,“靶征”是椎管内神经纤维瘤的特征,肿瘤呈多样的强化,常显示中央强化。边界模糊时,应考虑丛状神经纤维瘤。     

不典型神经鞘瘤及神经纤维瘤CT、MRI诊断

目的分析不典型神经鞘瘤和神经纤维瘤的CT和MRI表现,提高其诊断准确率. 资料与方法回顾性分析30例经手术病理证实的不典型神经鞘瘤及神经纤维瘤CT和MRI资料. 结果神经鞘瘤18例、神经纤维瘤12例.少见部位、肿瘤巨大、完全囊变、厚壁囊变、瘤周明显水肿及多发小结节影融合为其主要不典型表现.30例中有20例患者术前误诊（66.7%）. 结论不典型神经鞘瘤和神经纤维瘤定性诊断较困难,加强影像学表现与临床综合分析,有助于提高诊断符合率,MRI在定性诊断方面优于CT.     

纤维瘤病的MRI

纤维瘤病是一组多样的软组织病变,还没有一致地分类或治疗方法。作者对22例深部的纤维瘤病病人作了MR检查。22例在MR检查后几周内进行了广泛的手术切除。其中4例体检和MR检查显示复发。女17例、男9例。年龄9～62岁,MR采用0.35T、1.0T和1.5T的设备,未作增强检查。一些病例应用了表面线圈。矩阵128×128到256×256,1～4次激励。层厚3～5 mm。每个病人均获T_1加权象(100～600/16～20〔TR/TE〕)。质子密度加权象〔1000～2000/20～40〕和T_2加权象(2000～2500/60～80)。根据病变部位行矢状、横断和冠状面成象。受累部位包括胸壁(n=3)、腹、盆壁(n=1),下肢(n=12)、上肢(n=5),腹腔(n=2)。盆腔(n=1)和臂丛(n=2)。病变起源于筋膜(n=9)、肌肉(n=     

头部外伤促巨大神经纤维瘤生长1例

患者 ,男性 ,19岁。诊断 :左额、颞、顶部皮肤神经纤维瘤。患者自幼左颞部皮肤表面存在色素加深现象 ,7个月前被人用钝器击伤左颞顶部 ,加重 2周于 1997 0 5 0 9入院。左颞顶部轻度肿胀 ,无头皮裂伤及其它不适。于 1个月前在当地医院行“左颞顶部头皮包块”切除术 ,取包块上纵形切口 ,见出血多而缝合 ,未行病理检查。近 2周包块明显增大 ,表皮褐色斑随包块扩散 ,范围累及左额、颞顶部。大小约 2 0ｃｍ× 2 5ｃｍ× 5ｃｍ ,无神经系统定位体征 ,ＣＴ检查颅内未见异常。入院后行左额、颞顶部皮肤神经纤维瘤切除术。术中见左颞顶颅骨陈旧性线…     

椎管内脊膜瘤神经鞘瘤及神经纤维瘤MRI诊断与鉴别

目的：分析椎管内脊膜瘤神经鞘瘤及神经纤维瘤MRI影像表现。方法：搜集2001年7月-2003年5月经手术病理证实的25例髓外硬膜下占位以及跨跨硬膜内外占位病变3例，共28例。其中26例行平扫加增强，2例仅做平扫。结果：MRI定位准确率为10％。脊膜瘤17例，信号均匀，无明显囊变坏死者16例，具有典型“脊膜尾征”者5例；神经源性肿瘤11例，其影像复杂，强化形式亦多变，依据肿瘤是实体型或完全囊变型或混合型而出现不同的强化形式。结论：根据椎管内原发肿瘤的MRI表现可准确定位并推测其病理类型。     

足底硬纤维瘤的MRI特征分析

【摘要】目的：探讨足底硬纤维瘤的MRI表现。方法：回顾性分析18例经手术病理证实的足底软组织硬纤维瘤患者的MRI资料。所有患者行MRI常规平扫,14例行增强检查。结果：18例中11例（61%）肿瘤发生于前足,5例（28%）发生于后足,2例（11%）发生于中足;形态上,肿瘤呈片状2例（11%）,团块形4例（22%）,不规则形12例（67%）;边界不清6例（33%）,边界尚清12例（67%）。肿块最大径为2.3~10.8cm,中位数为3.7cm。2例（11%）为多发病灶。MRI显示病灶在T1WI上呈等或等~低信号,T2WI及短时反转恢复序列（STIR）上呈稍高或高信号,但均低于脂肪组织的信号;15例（83%）可见病灶内信号不均匀,高信号区内有不同比例的星芒状或条带状低信号,1例（6%）病灶内可见点状出血信号;18例病灶内均未见囊变及钙化。增强扫描显示病灶内于T1WI、T2WI上呈低信号的区域无明显强化,其余部分呈较均匀明显强化。结论：足底硬纤维瘤的MRI表现具有一定特征性,MRI可为病变的诊断和鉴别诊断提供重要参考。     

侵蚀性纤维瘤病的MRI诊断

目的分析侵蚀性纤维瘤病的MRI表现,探讨MRI对该病的诊断价值.资料与方法回顾性分析11例经手术及病理证实的侵蚀性纤维瘤病的MRI表现.结果全部病例肿块均沿肌纤维浸润性生长,累及多块肌肉.8例无包膜,1例包膜不完整,2例可见假包膜;8例可见斑片状T1WI、T2WI低信号;4例可见T1WI、T2WI与肌肉等信号区域;增强扫描肿块不同程度强化;而T1WI、T2WI低信号以及与肌肉等信号区域不强化.全部病例瘤周未见水肿,瘤内未见坏死囊变区. 结论侵蚀性纤维瘤病的MRI表现有一定的特征性,MRI检查对该病的定性诊断与鉴别诊断有重要的价值.     

腰部巨大丛状神经鞘瘤一例

病例资料患者,男,65岁。发现腰部包块60年,包块区皮肤破溃3天入院。患者于60年前外伤后发现腰部包块,即感疼痛,无破溃、发热,60年来未行特殊治疗,包块随年龄逐年增大,3天前包块破溃,门诊以腰部包块待查收入院。     

MRI growth patterns of plexiform neurofibromas in patients with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with an incidence of 1:3000. Approximately 30% of NF1 patients develop plexiform neurofibromas (PNF) which often cause severe clinical deficits. We studied the growth patterns of 256 plexiform neurofibromas (PNF) by magnetic resonance imaging (MRI) and associated disfigurement and functional deficits to determine whether there are definable growth types of these tumors. Retrospectively, we evaluated MRI scans obtained during 1997 to 2003 of 256 plexiform neurofibromas from 202 patients with NF1. Clinical investigation was carried out at the same time as the MRI scans. We identified three growth patterns: superficial in 59, displacing in 76, and invasive growth in 121 tumors. The majority (52%) of invasive PNF were found in the face, head and neck area. While superficial PNF primarily caused aesthetic problems, displacing PNF led in most cases to aesthetic problems and pain, while invasive PNF led mainly to functional deficits and disfigurement. Our study demonstrates that PNF have different growth patterns that are associated with specific clinical features. Classification of PNF may open new opportunities in clinical management, especially regarding decisions and options associated with surgical intervention.     

Interobserver reproducibility of volumetric MR imaging measurements of plexiform neurofibromas

OBJECTIVE: This article validates the reproducibility of MR imaging volumetric measurements for evaluating the growth of plexiform neurofibromas in neurofibromatosis type 1. CONCLUSION: Volumetric measurements of plexiform neurofibromas in neurofibromatosis 1 are reproducible.     

Extraaxial neurofibromas versus neurilemmomas: discrimination with MRI

OBJECTIVE: The purpose of our study was to evaluate whether MRI can discriminate between extraaxial neurofibromas and neurilemmomas. MATERIALS AND METHODS: MR images of 52 patients with a pathologically proven extraaxial neurofibroma or neurilemmoma were retrospectively reviewed by observers who were unaware of the surgical results, regarding the presence or absence of individual imaging criteria. MRI findings in 12 patients with a localized neurofibroma and 40 patients with a neurilemmoma were compared using the chi-square test or Fisher's exact test. RESULTS: MRI findings suggestive of neurofibroma (p < 0.05) were a target sign on T2-weighted images (58% in neurofibromas vs 15% in neurilemmomas), central enhancement (75% vs 8%), and a combination of both findings (63% vs 3%). MRI findings suggestive of a neurilemmoma (p < 0.05) were a fascicular appearance on T2-weighted images (25% vs 63%), a thin hyperintense rim on T2-weighted images (8% vs 58%), a combination of both findings (8% vs 48%), and diffuse enhancement (13% vs 67%). No significant difference was seen between neurofibromas and neurilemmomas for a centrally entering and exiting nerve (42% in neurofibromas vs 23% in neurilemmomas), a peripherally entering and exiting nerve (58% vs 77%), a cystic area (38% vs 64%), a low-signal margin (100% vs 100%), peripheral enhancement (13% vs 26%), or a target sign on contrast-enhanced images (11% vs 31%). CONCLUSION: MRI shows features helpful for differentiating extraaxial neurofibromas from neurilemmomas; however, no single finding or combination of findings allows definitive differentiation.     

Hemorrhagic nerve sheath tumors (plexiform neurofibromas) of the scalp: CT findings

Three cases of hemorrhagic nerve sheath tumors of the scalp are presented with emphasis on CT findings. Each mass produced a mixed pattern of CT density due to the combination of tumor and hemorrhage within it. The CT findings were remarkably similar in the three patients and included a calvarial abnormality underlying the mass in each.     

Automated detection and volume measurement of plexiform neurofibromas in neurofibromatosis 1 using magnetic resonance imaging.

An automated technique for segmentation and volumetric measurement of plexiform neurofibromas (PN) in neurofibromatosis 1 using short T1-inversion recovery magnetic resonance images is presented. The algorithm described implements heuristics derived from human-based recognition of lesions. This technique combines region-based with boundary-based segmentation. Two observers, who performed semi-automated volume calculations and manual tracings to estimate tumor volume, validated this method on 9 PNs of different size and location. This automated method was reproducible (coefficient of variation 0.6-5.6%), yielded similar results to manual tumor tracings (R = 0.999) and will likely improve the ability to measure PNs in ongoing clinical trials.     

Myxoid neurofibromas of the breast: mammographical, sonographical and MRI appearances

Neurofibromas arise from elements in the peripheral nervous system and are rarely detected in the breast. Neurofibromatosis is a phakomatosis that displays a wide spectrum of clinical expression with neurocutaneous abnormalities and involvement of multiple organ systems. Neurofibromas are more common in neurofibromatosis Type 1. They can show variable amounts of myxoid change, which affect their radiological findings. In this paper, we present a patient with neurofibromatosis Type 1 with mammographical, sonographical and MRI findings of myxoid neurofibromas in her left breast.     

Whole-body MRI of multiple myeloma: comparison of different MRI sequences in assessment of different growth patterns

Purpose

To determine sensitivity, specificity and inter-observer variability of different whole-body MRI (WB-MRI) sequences in patients with multiple myeloma (MM).

Methods and materials

WB-MRI using a 1.5 T MRI scanner was performed in 23 consecutive patients (13 males, 10 females; mean age 63 ± 12 years) with histologically proven MM. All patients were clinically classified according to infiltration (low-grade, n = 7; intermediate-grade, n = 7; high-grade, n = 9) and to the staging system of Durie and Salmon PLUS (stage I, n = 12; stage II, n = 4; stage III, n = 7). The control group consisted of 36 individuals without malignancy (25 males, 11 females; mean age 57 ± 13 years). Two observers independently evaluated the following WB-MRI sequences: T1w-TSE (T1), T2w-TIRM (T2), and the combination of both sequences, including a contrast-enhanced T1w-TSE with fat-saturation (T1 ± CE/T2). They had to determine growth patterns (focal and/or diffuse) and the MRI sequence that provided the highest confidence level in depicting the MM lesions. Results were calculated on a per-patient basis.

Results

Visual detection of MM was as follows: T1, 65% (sensitivity)/85% (specificity); T2, 76%/81%; T1 ± CE/T2, 67%/88%. Inter-observer variability was as follows: T1, 0.3; T2, 0.55; T1 ± CE/T2, 0.55. Sensitivity improved depending on infiltration grade (T1: 1 = 60%; 2 = 36%; 3 = 83%; T2: 1 = 70%; 2 = 71%; 3 = 89%; T1 ± CE/T2: 1 = 50%; 2 = 50%; 3 = 89%) and clinical stage (T1: 1 = 58%; 2 = 63%; 3 = 79%; T2: 1 = 58%; 2 = 88%; 3 = 100%; T1 ± CE/T2: 1 = 50%; 2 = 63%; 3 = 100%). T2w-TIRM sequences achieved the best reliability in depicting the MM lesions (65% in the mean of both readers).

Conclusions

T2w-TIRM sequences achieved the highest level of sensitivity and best reliability, and thus might be valuable for initial assessment of MM. For an exact staging and grading the examination protocol should encompass unenhanced and enhanced T1w-MRI sequences, in addition to T2w-TIRM.     

Craniopharyngiomas: identification of different semiological patterns with MRI

Our objectives were to analyze different semiological patterns in craniopharyngiomas studied with CT and MR sequences. Retrospective study of 26 patients with confirmed craniopharyngiomas. All cases were examined with CT and MR imaging using a variety of pulse sequences (spin echo, inversion recovery, gradient echo in-phase and opposed-phase). The analyzed component patterns were classified as solid, calcium, proteic-like, cerebrospinal fluid (CSF)-like, hematic-like, and fatty patterns. The different patterns were related by means of contingency tables and the Fisher exact test and also to epidemiological findings and tumor size. A solid pole was detected in all patients, whereas a cystic component was present in 92.3% of the cases. Calcification was visualized in 65.3%, proteic-like in 53.8%, CSF-like in 23%, hematic-like in 19.2%, and fatty component in 15.3%. There were no statistical associations between patterns, with the exception that in no case did CSF-like and proteic-like patterns coexist ( P=0.004). Tumor size was related to components. Hematic-like (17.0+/-18.9 vs 3.9+/-2.6 mm, non-present vs present) and CSF-like (16.9+/-19.6 vs 6.5+/-4.0 mm) patterns were observed most frequently in smaller tumors, whereas larger tumors usually had proteic-like (5.9+/-5.4 vs 21.1+/-21.0 mm) and calcified (4.6+/-1.9 vs 19.1+/-19.9 mm) patterns. Computed tomography and a combination of different MR images frequently allow the detection of different semiological patterns in these tumors. Semiological patterns were correlated only to tumor size.     

非脑膜瘤脑膜病变的MRI表现及强化模式

目的 分析不同脑膜病变的MR成像表现，探讨MRI尤其是脑膜强化模式对各种脑膜病变的诊断及鉴别诊断价值。方法 临床资料完整的脑膜病变61例，其中感染性脑膜炎27例；非感染性脑膜炎4例，包括嗜酸性肉芽肿2例，wegener肉芽肿l例，病因不明l例；脑膜转移瘤12例；脑膜淋巴瘤2例；脑梗死8例；手术后脑膜改变8例。MR常规扫描后均行钆喷替酸葡甲胺(Gd-DTPA)增强扫描。结果 (1)MR平扫：异常脑膜改变仅3例，其中脑膜增厚l例，脑膜结节2例。(2)MR增强扫描：61例呈3种脑膜强化模式，分别为I型、Ⅱ型、Ⅲ型强化模式。I型强化模式即硬脑膜-蛛网膜强化，有19例；Ⅱ型强化模式即蛛网膜-软脑膜强化，有32例；Ⅲ型强化模式即全脑膜强化(包括硬脑膜及软脑膜)，有10例。结论 不同脑膜病变MR成像表现尤其是增强模式有一定特点。各种脑膜病变增强模式对于鉴别各种脑膜病变，发现病变细节，提示临床诊疗均有明显意义。