鼻窦海绵状血管瘤的CT和MRI诊断

目的探讨鼻窦海绵状血管瘤的CT和MRI表现，提高其诊断准确性。方法回顾性分析30例经病理证实的鼻窦海绵状血管瘤患者的影像资料。结果发生于上颌窦者25例，前组筛窦3例，蝶窦2例。30例均可见病变向邻近的部位蔓延，压迫相应结构，但分界尚清楚，MRI较CT显示更清楚。CT表现为受累的鼻窦均有不同程度的扩大，窦壁骨质受压、变形，28例骨质不连续并形成缺损，以上颌窦内壁最常见（21例），残端骨质伴硬化8例，内可见软组织肿块影，边界清楚，密度不均匀，其中10例见静脉石影；16例增强后呈明显不均匀强化，内有散在、形态不一的明显强化区域。与脑组织比较病变在MR T2 W1呈低信号4例，中等信号14例；在T2 WI呈高信号16例，中等信号2例，但信号不均匀，其内可见形态及数量不一的低信号影；增强后病变呈显著不均匀强化，外观呈蜂窝状8例，斑驳状10例；8例动态增强扫描均显示渐进性强化。结论典型骨质改变加静脉石可提示该病诊断；MR T2 WI不均匀高信号、渐进性强化、斑驳状或蜂窝状表现，也是诊断该病的特征性征象；联合使用CT和MRI可为该病诊断和治疗提供更准确、可靠的信息。     

颅内海绵状血管瘤的CT和MRI诊断

目的 探讨CT和MRI对颅内海绵状血管瘤的表现和诊断价值。资料与方法 经手术病理证实的颅内海绵状血管瘤22例,其中脑内型海绵状血管瘤21例,脑外型海绵状血管瘤1例。10例行CT检查,16例行MRI检查,13例行MRA检查。结果 脑内型海绵状血管瘤可位于脑内任何部位,单发病灶多见,周围无或轻度水肿,无明显占位效应。CT平扫为稍高密度影,钙化占72．7％,增强扫描大都无强化;MR T1WI表现为桑葚状混杂高信号．周围有云絮状低信号环,增强后病灶大都无强化;MRA检查未见异常血管。脑外型病灶位于中颅窝、鞍旁,MRI呈类似哑铃形较均匀的稍长T1、长T2信号,增强扫描见明显均匀强化．MRA检查未见异常血管。结论 脑内型海绵状血管瘤的MRI表现较有特异性,结合CT和MRA可明确诊断;脑外型者易误诊,对CT和MRI表现类似的中颅窝脑膜瘤,应考虑到本病的可能。     

颅内非典型海绵状血管瘤的CT和MRI分析

目的提高颅内非典型海绵状血管瘤的CT和MRI正确诊断。方法回顾分析12例颅内非典型海绵状血管瘤的CT和MRI,并与手术病理进行对照。在12例病人中,11例作CT检查,10例作MRI检查,CT和MRI同时检查9例。结果本组12例中,1例位于鞍内,1例位于四脑室内,5例位于脑内,4例位于中颅窝,1例位于后颅窝。出现脑水肿3例、囊变1例,伴脑出血4例。本组定位诊断100%,定性诊断,11例错误,1例未作定性诊断。结论非典型海绵状血管瘤定性诊断较困难,应强调影像学与临床综合分析。     

眼眶海绵状血管瘤的影像学诊断

目的:分析眼眶海绵状血管瘤的超声、CT及MRI征象,探讨各影像技术对海绵状血管瘤的诊断价值。方法:回顾性分析经手术病理证实的30例海绵状血管瘤患者的超声、CT及MRI影像学表现,并与手术结果对照。结果:超声显示海绵状血管瘤呈圆形或类圆形,内回声多且分布均匀,声衰减少,轻度可压缩性,内部缺乏血流信号;CT显示肿瘤位于肌锥内,边缘清楚,软组织密度,根据眶尖处是否存在透明三角区可判断是否向颅内蔓延,增强扫描呈渐进性强化征象;MRI能清楚显示肿瘤与眼外肌及视神经的关系。结论:超声能够揭示海绵状血管瘤的组织学特点,CT及MRI可对肿瘤准确定位,揭示病变与周围组织关系。选择超声与CT或超声与MRI相结合的检查方法可对海绵状血管瘤作出诊断。     

眼眶海绵状血管瘤的影像学表现及其意义

目的 研究眼眶海绵状血管瘤的ＣＴ和ＭＲＩ征象,并着重探讨海绵状血管瘤的特异性征象即“渐进性强化”,及其在诊断和鉴别诊断海绵状血管瘤中的价值。方法 对经手术病理证实的眼眶海绵状血管瘤５８例进行回顾性分析。所有病例均行Ｂ超检查,其中ＣＴ检查４８例,ＣＴ增强扫描４３例,动态增强扫描１０例;ＭＲＩ检查２７例,动态增强扫描２４例。结果 ＣＴ增强后３６例（８３．７％）显示不同程度的片状强化,１０例ＣＴ动态增强     

颅骨海绵状血管瘤的CT和MRI诊断(附11例报告)

目的:分析颅骨海绵状血管瘤的CT和MRI特点。方法:回顾性分析11例(男3例,女8例,年龄12~65岁,平均44岁)经病理证实的颅骨海绵状血管瘤的临床表现、术前CT平扫和MRI平扫和增强扫描资料,观察肿瘤的形状、密度、边界、MRI信号变化、增强表现及周围软组织情况,根据颅骨外板是否破坏,将肿瘤分两组,比较肿瘤最大径的组间差异。结果:所有病例术前均表现为无痛性皮下肿物。7例(64%)位于额骨,顶骨和枕骨各2例。病变均表现为椭圆形,边界清晰,边缘无硬化。CT值自117~1048HU不等。7例(64%)外板破坏的肿瘤最大横径为(2.7±0.80)cm,与4例(37%)外板无破坏的肿瘤大小(2.33±0.88)cm差别无统计学意义(P=0.488)。MRI平扫均表现为高低信号混杂影,增强后强化不均匀,强化幅度不一。周围软组织和脑实质信号正常。结论:颅骨海绵状血管瘤表现出一定的破坏颅骨外板向颅外生长倾向,综合CT和MRI检查有助于更好地显示该病的影像学特点。     

不典型颅内海绵状血管瘤的CT、MRI诊断初探

目的 探讨颅内海绵状血管瘤(ICA)的CT和MRI不典型表现.资料与方法 回顾性分析经手术病理证实的不典型ICA9例,男5例,女4例,年龄11～72岁,平均35岁.所有病例均行MRI平扫及增强检查,其中4例行CT扫描.结果 9例均位于脑内.病灶最大径平均值5.5cm.行CT检查的4例中,2例表现为等、高密度,2例表现为等、低密度;3例病灶内可见钙化.9例T1WI和T2WI呈混杂信号,周围低信号环4例,囊实性病灶5例,囊内见液平面3例,其中囊变伴附壁结节4例,6例出现明显灶周水肿.增强扫描8例呈明显不均匀强化,1例无明显强化.结论 发现瘤体巨大伴有囊性变、瘤体占位效应、病变多种形式的强化等ICA不典型的CT和MRI征象时,应考虑ICA的诊断.     

MRI及CT对软组织海绵状、蔓状血管瘤的诊断价值

目的 :探讨软组织海绵状血管瘤 (CH)、蔓状血管瘤 (RH)的MRI、CT表现及诊断价值。方法 :回顾性总结经手术及病理证实 2 1例CH及 14例RH的MRI和CT表现。结果 :CH在MRI上呈团块或不规则状 ,边界清楚 ,血窦呈不均匀等T1长T2 信号 ,瘤内纤维、脂肪组织呈花边、条状分隔或串珠样短T2 信号 ;CT示肿瘤密度不均 ,有分隔 ,呈中等度强化。RH形态不规则、边界欠清 ,MRT1WI及T2 WI可见其内管状流空血管影 ;CT示瘤内见结节状、蚓状等、高密度影 ,部分有钙化、静脉石 ,增强扫描呈结节状、条状明显强化。结论 :CH和RH影像表现具有相对特征性 ;CT有利于显示瘤内钙化、静脉石 ,MRI则可反映瘤内脉管及非血管组织成分 ,对定性诊断有重要的价值。     

眼眶海绵状血管瘤的CT、MRI诊断

目的：研究眼眶海绵状血管瘤的CT、MRI成像特点，提高诊断率。资料与方法：选取20例经手术病理证实的眶内海绵状血管瘤，均行CT平扫、MRI平扫及增强扫描，8例行CT增强扫描，分析其CT、MRI征像特点及检查手段。结果：CT能显示肿瘤钙化，眶壁骨质改变，呈渐进性强化，最后明显均匀强化，MRI三维成像能发现微小病变，显示肿瘤毗邻关系更佳，压脂像冠状位扫描能清晰显示肿瘤与视神经、眼外肌的关系。结论：CT、MRI互补，能明显提高眶内海绵状血管瘤的诊断率．     

脑内海绵状血管瘤影像诊断

目的：探讨脑内海绵状血管瘤的CT、MRI影像表现特点及诊断价值。方法：回顾性分析28例脑内海绵状血管瘤的影像资料,经CT检查18例,6例增强扫描,MR检查28例,10例增强扫描,11例经手术病理证实,3例做伽马刀治疗,14例随诊证实。结果：脑内海绵状血管瘤CT平扫表现为稍高或混杂密度影,边界清晰,病灶内可见单发或多发点状或斑片状钙化,少数可表现为血肿密度,增强扫描轻度不均匀强化或无强化。MR典型表现为T2WI及T1WI高低不均匀信号,呈＂爆米花＂样,周边可见低信号环,部分病灶为T2WI中央高、周边低信号,T1WI略低信号,边界模糊;T2WI为高信号,T1WI中央高、周边低信号;少数病灶表现为T2WI、T1WI均为高信号且信号均匀。DWI呈中间混有高信号的不均匀黑色低信号或均匀黑色低信号且较T1WI及T2WI范围加大,增强扫描表现为不均匀强化或无明显强化。结论：脑内海绵状血管瘤以MRI表现更典型,MRI检查T2WI及DWI序列是诊断及随访脑内海绵状血管瘤的最佳方法。     

颈部舌骨上区肿瘤及肿瘤样病变的CT和B超诊断

目的：探讨ＣＴ和Ｂ超对舌骨上区肿瘤及肿瘤样病变的定位、定性诊断能力。材料和方法：复习和分析经手术及病理证实的舌骨上颈动脉间隙及相邻部位肿瘤与肿瘤样病变３３例。主要包括神经源肿瘤１１例、血管性肿物３例、淋巴结病变１２例、涎腺肿瘤４例及腮裂囊肿３例等。３３例均行ＣＴ扫描，１７例行Ｂ超扫描。结果：淋巴结肿物位于颈内动、静脉外方，使血管向内侧移位。神经源肿瘤位于颈内动脉内后方，使其向外前移位。淋巴结转移瘤增强后边缘不规则环状强化，中心液化坏死。神经源肿瘤增强后肿物无明显强化，但边缘多有环状低密度区。增强ＣＴ扫描能观察病变的内部结构及其与血管的关系，Ｂ超在鉴别肿物的囊、实性及肿物与血管的关系方面能提供补充信息。结论：ＣＴ结合Ｂ超能准确评估颈部病变的部位及性质。     

Functional MRI of the patellofemoral joint: comparison of ultrafast MRI,motion-triggered cine MRI and static MRI

In recent years ultrafast gradient echo sequences have been used in MRI that allow functional MRI studies of the joints during active motion in an acquisition time of seconds. To evaluate the feasibility and usefulness of ultrafast MRI (u), patellar tracking from 30° of flexion to knee extension (0°) was analysed and compared with motion-triggered cine MRI (m) and a static MRI technique (s). The different imaging methods were compared in respect of the patellofemoral relationship, the examination time and image quality. Eight healthy subjects and four patients (in total 18 joints) with patellar subluxation or luxation were examined. Significant differences between the static MRI series without quadriceps contraction and the functional MRI studies (motion-triggered cine MRI and ultrafast MRI) were found for the patellar tilt angle (PTA: P _m/s = 0.01; P _u/s < 0.01). In the dynamic joint studies there was no statistical difference of the regression coefficients between the motion-triggered cine MRI studies and the ultrafast MRI studies (P _m/u = 0.8). The findings of the functional MRI studies compared with the static MRI images were significantly different for the lateralisation of the patella, expressed by the lateral patellar displacement (LPD: P _m/s < 0.01; P _u/s = 0.01) and bisect offset (BSO: P _m/s = 0.01; P _u/s < 0.05). No significant differences in patellar lateralisation were found between motion-triggered cine MRI and ultrafast MRI (LPD: P _m/u = 0.89; BSO: P _m/u = 0.33). Ultrafast MRI was superior to motion-triggered cine MRI in terms of the reduction in imaging time and improvement of the image quality. Correspondence to: C. Muhle     

Intraoperative,real-time,functional MRI

Functional MRI (fMRI) methods have been demonstrated to noninvasively identify motor-sensory, visual, and other areas of eloquent cortex for guiding surgical intervention. Typically, fMRI data are acquired preoperatively during a conventional surgical planning MRI examination. Unlike direct cortical stimulation at the time of surgery, however, preoperative fMRI methods do not account for the potential movement of tissues (relative to the time of functional imaging) that may occur in the surgical suite as a direct result of the intervention. Recently, an MRI device has been demonstrated for use in the surgical suite that has the potential to reduce the extent of cortical exposure required for the intervention. However, the invasive requirements of cortical mapping may supersede the invasive requirements of the surgical intervention itself. Consequently, we demonstrate here a modification to the intraoperative MRI device that facilitates a noninvasive, real-time, functional MR examination in the surgical suite.     

Multiple-angle, variable-interval, nonorthogonal MRI

Multiple-angle, variable-interval, nonorthogonal (MAVIN) MRI is a new, time-saving technique that allows for the independent choice of slice angle and position for each slice in a multiangle pulse sequence. By appropriate adjustment of the slice-select radiofrequency pulse and the slice-select and readout magnetic-field gradients, the interval and angle of each slice may be individually chosen. MAVIN can reduce examination time in studies of the lumbar spine, orbits, knees, and heart, where nonparallel oblique scanning may be necessary and would otherwise require the use of additional pulse sequences. Loss of signal in the region of intersection of multiple planes due to local changes in effective repetition time is a practical limitation. For this reason, scan planes are chosen so that the intersection does not overlie the region of interest.     

主动脉夹层几种磁共振影像的评价和比较

目的：评价和比较ＭＲＩＳＥ常规序列、电影（ｃｉｎｅ）ＭＲＩ及ＭＲ血管造影（ＭＲＡ）对主动脉夹层的诊断价值。材料和方法：对２５例主动脉夹层进行了３１人次ＭＲ检查。其中包括胸腹主动脉ＳＥ序列３１人次，胸主动脉ｃｉｎｅＭＲＩ２３人次及腹主动脉二维时间飞跃（２ＤＴＯＦ）ＭＲＡ２１人次。将ｃｉｎｅＭＲＩ及ＭＲＡ分别与其相应ＳＥ序列ＭＲ表现进行比较。结果：胸主动脉ｃｉｎｅＭＲＩ２３例与相应ＳＥ序列比较，两者所有病例均显示内膜片及真假两腔，但显示破口分别为１４和９例。显示头臂血管受累分别为７和２条。腹主动脉ＭＲＡ２１例与相应ＳＥ序列比较，两者均显示内膜片和真假两腔，但显示破口或再破口者分别为４和２例，腹主动脉分支血管受累分别为３９和１４条。结论：ＭＲ是诊断主动脉夹层的最佳影像学方法之一。在常规ＳＥ序列基础上，辅以ｃｉｎｅＭＲＩ和ＭＲＡ技术将大大提高ＭＲ总体观察夹层范围、内膜破口以及分支受累的能力，给临床提供更多的信息。     

MRI of hypertrophic cardiomyopathy: part I, MRI appearances

OBJECTIVE: We present a two-part review about the use of MRI in patients with hypertrophic cardiomyopathy (HCM). This article, Part 1, focuses on the MRI appearances of HCM. CONCLUSION: MRI has proven to be an important tool for the evaluation of patients suspected of having HCM because it can readily diagnose those with phenotypic expression of the disorder and can potentially identify the subset of patients at risk of sudden cardiac death.     

Associations among q-space MRI, diffusion-weighted MRI and histopathological parameters in meningiomas

Objectives

The purposes of this MR-based study were to calculate q-space imaging (QSI)–derived mean displacement (MDP) in meningiomas, to evaluate the correlation of MDP values with apparent diffusion coefficient (ADC) and to investigate the relationships among these diffusion parameters, tumour cell count (TCC) and MIB-1 labelling index (LI).

Methods

MRI, including QSI and conventional diffusion-weighted imaging (DWI), was performed in 44 meningioma patients (52 lesions). ADC and MDP maps were acquired from post-processing of the data. Quantitative analyses of these maps were performed by applying regions of interest. Pearson correlation coefficients were calculated for ADC and MDP in all lesions and for ADC and TCC, MDP and TCC, ADC and MIB-1 LI, and MDP and MIB-1 LI in 17 patients who underwent subsequent surgery.

Results

ADC and MDP values were found to have a strong correlation: r?=?0.78 (P?=?<0.0001). Both ADC and MDP values had a significant negative association with TCC: r?=?–0.53 (p?=?0.02) and –0.48 (P?=?0.04), respectively. MIB-1 LI was not, however, found to have a significant association with these diffusion parameters.

Conclusion

In meningiomas, both ADC and MDP may be representative of cell density.

Key Points

? Diffusion-weighted MRI offers possibilities to assess the aggressiveness of meningiomas. ? The q-space imaging-derived mean displacement correlates strongly with apparent diffusion coefficients. ? Both diffusion parameters showed a strong negative association with tumour cell counts. ? Derived mean displacement may help assess the aggressiveness of meningiomas preoperatively.     

MRI safety update 2008: part 2, screening patients for MRI

OBJECTIVE: This article is the second part of a two-part series on MRI safety. In this article, part 2, the topic of screening patients for MRI procedures is addressed. CONCLUSION: To prevent incidents and accidents associated with MRI, it is necessary to regularly revisit the safety topics that directly impact patient management especially with respect to the subjects that are "new," those that should be reassessed because of recent changes, topics that deserve emphasis because of controversy or confusion, and information that should be considered in light of new findings.