Epidermoid cyst of the conus medullaris: atypical MRI and angiographic features

We report a 50-year-old man with an epidermoid cyst of the conus medullaris which showed a nodular gadolinium enhancement on MRI and a blush on angiography. These radiological features are compared with pathological examination.     

Epidermoid cyst of the skull with nonpulsatile tinnitus

We report an intradiploic epidermoid cyst of the skull responsible for transverse sinus compression and presenting with nonpulsatile tinnitus. Plain films and CT both demonstrated the tumour. Cerebral angiography showed best the degree of narrowing of the right transverse sinus, accompanied with turbulent flow probably leading to tinnitus. MRI demonstrated accurately both the tumour and the dural sinus compression. The tumour was totally removed, cranioplasty was performed, and the patient was discharged free of symptoms. Received: 28 May 1997 Accepted: 27 October 1997     

颅内不典型表皮样囊肿MR表现和病理对照分析

目的 探讨颅内不典型表皮样囊肿的MR表现及其与病理所见的关系.方法 回顾性分析7例颅内不典型表皮样囊肿的MR表现,并与手术病理所见对照.全部病例均行MR平扫检查,2例行MR增强扫描,1例行CT扫描.结果 4例表皮样囊肿位于小脑半球实质,2例位于大脑半球实质,1例位于小脑周围.T1WI 6例表皮样囊肿呈高信号,1例呈等信号,T2WI 5例呈很低信号,2例呈高信号.增强扫描囊肿不强化.病理检查镜下可见囊肿内大量蛋白物质.结论 颅内表皮样囊肿呈短T1和等T1信号主要与囊肿内存在大量蛋白物质有关,需要与颅内短T1信号的病变鉴别.     

Sturge-Weber syndrome: diffusion magnetic resonance imaging and proton magnetic resonance spectroscopy findings

We report on the diffusion magnetic resonance imaging (MRI) and proton MR spectroscopy findings of a 26-year-old female patient with Sturge-Weber syndrome. Echo-planar trace diffusion MRI revealed mildly high signal intensity changes at parieto-occipital lobes on b = 1000 s/mm² images, suggesting restricted diffusion. On corresponding apparent diffusion coefficient maps, those areas had moderately high signal intensity and high apparent diffusion coefficient values (around 0.9×10(-3) mm²/s) compared with the contralateral symmetrical normal side of the brain (0.776×10(-3) mm²/s). This finding was consistent with increased motion of water molecules (disintegration of the neural tissue) in these regions. Proton MR spectroscopy revealed decreased N-acetyl aspartate and increased choline peaks, indicating disintegration of neural tissue associated with neuronal loss as well.     

Myositis ossificans of psoas muscle: magnetic resonance imaging findings

Myositis ossificans is a benign, localized, self-limiting ossifying soft tissue mass with unknown pathogenesis. It may be confused with a malignant tumor of bone or soft tissues, especially in the early stages of the disease. In this report, we present a case of myositis ossificans affecting unilateral psoas muscle, which to our knowledge is a very uncommon location. There was no history of trauma. We describe the imaging findings and clues to early diagnosis of myositis ossificans.     

睾丸生殖细胞肿瘤的MRI诊断

目的：探讨睾丸生殖细胞肿瘤的 MRI 表现,提高对该疾病的 MRI 诊断水平。方法回顾性分析经手术病理证实的25例睾丸生殖细胞肿瘤患者临床及 MRI 资料,所有病例均行 MRI 平扫,其中16例行动态 MRI 增强扫描。利用 MRI 对睾丸肿瘤的大小、形态、信号特点、毗邻关系、强化方式及肿瘤血管情况进行评估,并与病理对照。结果25例睾丸生殖细胞肿瘤中,精原细胞瘤10例,其中 T2 WI 呈均匀低信号8例,稍低信号2例,增强扫描轻度结节样强化5例,明显均匀强化2例,其中4例可见纤维间隔强化;卵黄囊瘤4例,T1 WI 呈等低信号,T2 WI 呈稍高信号,增强扫描后肿瘤呈渐进式强化;成熟型畸胎瘤、表皮样囊肿、混合性生殖细胞肿瘤各3例,T1 WI 呈混杂低信号,T2 WI 呈混杂高信号;胚胎性癌2例,T1 WI 呈等低信号,T2 WI 呈混杂低信号,其内可见出血信号,增强扫描呈分隔强化。结论MRI 对睾丸生殖细胞肿瘤诊断正确率较高,对其病理分型、分期及鉴别诊断具有重要价值。     

颅内表皮样囊肿和蛛网膜囊肿的DWI鉴别诊断

目的:探讨磁共振扩散加权成像(DWI)对颅内表皮样囊肿和蛛网膜囊肿的鉴别诊断价值。方法:对20例颅内表皮样囊肿和15例颅内蛛网膜囊肿患者进行常规MRI及DWI检查,并获得表观扩散系数(ADC)图,分别测量病变区、健侧脑组织及健侧侧脑室内脑脊液的ADC值并进行统计学分析。结果:表皮样囊肿和蛛网膜囊肿在T1WI和T2WI上呈相同的信号改变;在DWI上表皮样囊肿呈高信号,而蛛网膜囊肿呈低信号;表皮样囊肿的ADC值[(10.197±0.329)×10-4mm2/s]明显低于蛛网膜囊肿[(30.098±1.510)×10-4mm2/s],差异有显著性意义(P<0.05)。结论:DWI对于表皮样囊肿与蛛网膜囊肿的鉴别诊断具有重要价值。     

An unusual cause of susceptibility artifact in magnetic resonance imaging

Magnetic susceptibility artifact has been documented with various implants and devices, which require appropriate identification with screening of patients prior to subjecting them to magnetic resonance examination. We performed cardiovascular magnetic resonance (CMR) examination of the aorta in a 24-year-old woman in the setting of repaired aortic coarctation, and found magnetic susceptibility artifact arising from the stomach in the absence of known susceptibility artifact-producing material in this region. Further history revealed that she had ingested a prenatal vitamin prior to imaging, prompting experimental analyses that led us to conclude that iron-containing vitamins may be a source of magnetic susceptibility artifact.     

颅内表皮样囊肿的影像与病理所见对照分析

目的探讨颅内表皮样囊肿的常见及特殊影像表现与病理所见的关系。资料与方法回顾性分析44例表皮样囊肿的临床资料和影像学表现。全组病例均行MRI扫描,其中3例行扩散加权成像(DWI)检查,20例有CT平扫资料,1例在MRI检查的同时行X线颅骨平片检查。结果病变位于桥小脑角及桥池者24例,桥池及鞍上池者5例,鞍旁5例,大脑纵裂2例,第四脑室2例,板障2例,前颅凹2例,松果体区1例,内听道及中耳1例。其中6例影像学表现特殊,与病理检查对照,发现囊内含较多蛋白、脂类物质、胆固醇结晶以及发生囊内出血、钙化。液体衰减反转恢复序列(FLAIR)像和DWI能清楚显示位于基底池内的表皮样囊肿,并能与蛛网膜囊肿相鉴别。结论FLAIR和DWI是诊断颅内表皮样囊肿非常有价值的检查方法。     

Advanced magnetic resonance imaging findings in salivary gland tumors

Salivary gland tumors (SGTs) make up a small portion (approximately 5%) of all head and neck tumors. Most of them are located in the parotid glands, while they are less frequently located in the submandibular glands, minor salivary glands or sublingual gland. The incidence of malignant or benign tumors (BTs) in the salivary glands varies according to the salivary gland from which they originate. While most of those detected in the parotid gland tend to be benign, the incidence of malignancy increases in other glands. The use of magnetic resonance imaging (MRI) in the diagnosis of SGTs is increasing every day. While conventional sequences provide sufficient data on the presence, localization, extent and number of the tumor, they are insufficient for tumor specification. With the widespread use of advanced techniques such as diffusion-weighted imaging, semi-quantitative and quantitative perfusion MRI, studies and data have been published on the differentiation of malignant or BTs and the specificity of their subtypes. With diffusion MRI, differentiation can be made by utilizing the cellularity and microstructural properties of tumors. For example, SGTs such as high cellular Warthin’s tumor (WT) or lymphoma on diffusion MRI have been reported to have significantly lower apparent diffusion values than other tumors. Contrast agent uptake and wash-out levels of tumors can be detected with semi-quantitative perfusion MRI. For example, it is reported that almost all of the pleomorphic adenomas show an increasing enhancement time intensity curve and do not wash-out. On quantitative perfusion MRI studies using perfusion parameters such as Ktrans, Kep, and Ve, it is reported that WTs can show higher Kep and lower Ve values than other tumors. In this study, the contribution of advanced MRI to the diagnosis and differential diagnosis of SGTs will be reviewed.     

Supracerebellar arachnoid cyst and reversible tonsillar herniation: magnetic resonance imaging and pathophysiological considerations

Summary A large supracerebellar arachnoid cyst was associated with herniation of the cerebellar tonsils and deformity of the cervicomedullary junction in an adult. Magnetic resonance imaging showed partial restoration of normal anatomy following surgery and clinical improvement, which helped in the formulation of a etiopathogenetic hypotheses.     

Central nervous system aspergillosis: magnetic resonance imaging, diffusion-weighted imaging, and magnetic resonance spectroscopy features

Aspergillus infection is invasive in nature in the immunosuppressed population and disseminates throughout the body, with the brain being a common site. Conventional magnetic resonance imaging (MRI) combined with diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) play a life-saving role in the early diagnosis and treatment monitoring of this potentially fatal infection. We present MRI, DWI, and MRS findings of a case of central nervous system aspergillosis with treatment follow-up.     

颅内表皮样囊肿的MRI诊断

目的;分析颅内表皮样囊肿的ＭＲＩ表现。方法：收集经手术病理证实的颅内表内表皮样囊肿１４例,重点分析肿瘤的好发年龄,部位、ＭＲＩ信号特点及增强情况。结果：在本组病例中,年龄最小１６岁,最大４５岁,平均年龄２８岁,Ｔ１加权像呈低信号（９例）,低,等混杂信号（３例）、高信号（２例）、肿瘤在Ｔ２加权像上均呈高信号,７例行增强均无强化。结论：颅内表皮囊肿具有特征性ＭＲＩ表现。     

Popliteal cysts: a reassessment using magnetic resonance imaging

The advent of magnetic resonance imaging (MRI) prompted the reevaluation of the incidence of popliteal cyst and its associated injuries. We reviewed more than 1000 consecutive MRI examinations of the knee performed on patients referred for evaluation of internal derangement. We report a 5% incidence of popliteal cyst, which is lower than has previously been determined. We believe that the reported higher incidence was due to arthrographic distention of normal, collapsed bursae. The strong association between popliteal cyst and tear of the medial meniscus is confirmed. We report for the first time to our knowledge the 13% association between popliteal cyst and complete tear of the anterior cruciate ligament.     

Diffusion-weighted magnetic resonance imaging in the detection of testicular torsion: feasibility study

Purpose:

To investigate the feasibility and usefulness of diffusion‐weighted magnetic resonance imaging in the detection of testicular torsion.

Materials and Methods:

Institutional Review Board approval and informed consent from all participants were obtained. Consecutive 28 patients with acute scrotal symptoms were included in this study. Fat‐suppressed T2‐weighted, dynamic subtraction contrast‐enhanced, and diffusion‐weighted images were obtained in the coronal plane with a 1.5 T MR unit. An apparent diffusion coefficient (ADC) map was reconstructed from the diffusion‐weighted images obtained with b‐factor of 0 and 800 s/mm². Comparisons of ADC values between the affected and nonaffected testes were performed with Mann–Whitney's U‐test.

Results:

Diffusion‐weighted and ADC images with diagnostic quality were obtained in 23 out of the 28 patients (82%). In testicular torsion (n = 9), the mean ADC value of the twisted testes was significantly lower than that of the nonaffected testes (0.750 ± 0.297 vs. 1.017 ± 0.165 × 10^?3 mm²/sec, P < 0.05). In other scrotal disorders (n = 14), there was no significant difference in the mean ADC value of the testes between the affected and nonaffected side (P = 0.655). The affected‐to‐nonaffected ratio of ADC value was significantly lower in testicular torsion than that in other scrotal disorders (P < 0.05).

Conclusion:

Diffusion‐weighted imaging of the scrotum with testicular ADC measurement can allow for the detection of testicular torsion without any use of contrast media. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.

     

颅骨表皮样囊肿的CT及MRI特征

目的探讨颅骨表皮样囊肿(SEC)的CT和MRI影像学特点,以提高对该病的认识。资料与方法回顾性分析10例经手术病理确诊的SEC的CT及MRI表现。9例行CT平扫;8例行MRI检查,其中6例包含扩散加权成像(DWI)序列。8例MRI检查中2例行MRI平扫,4例行MRI平扫加增强检查,2例只行MRI增强检查;其中7例同时行CT及MRI检查。结果病变均为单发,起自板障。9例CT平扫示颅骨呈膨胀性改变,7例密度不均,其中5例病变可见钙化;2例病变密度均匀。6例MRI平扫,4例呈以长T1、长T2为主混杂信号,1例呈均匀长T1、长T2信号,1例呈短T1、长T2信号。6例DWI序列中5例呈高信号,1例呈低信号;表观扩散系数(ADC)图重组后,1例呈稍高信号,1例呈高信号,4例呈稍低信号。6例MRI增强检查,2例病变无强化;4例病变内部和/或边缘强化,同时1例邻近硬膜明显强化。结论SEC的CT及MRI表现有一定的特征性,影像学检查有助于其定位及定性诊断。     

脑内型表皮样囊肿的CT和MRI诊断

目的探讨脑内型表皮样囊肿的CT和MRI影像表现特点,提高对脑内型表皮样囊肿影像诊断的准确性。资料与方法回顾性分析5例经手术病理证实的脑内型表皮样囊肿患者的CT和MRI影像资料。5例患者均行CT平扫检查,其中4例行CT增强检查。5例患者中4例行MRI平扫检查,其中2例行MRI增强检查。结果 5例中,3例位于小脑半球,1例位于基底节区,1例位于额叶。肿瘤呈不规则形或分叶状,与周围组织分界清晰。CT平扫为较均匀或轻度不均匀低密度,CT值-22～26 HU之间。MRI平扫T1WI上肿瘤呈不均匀低信号,内部可见散在絮状略高信号;T2WI及液体衰减反转恢复(FLAIR)图像上呈不均匀高信号。CT及MRI增强检查病灶均无明显强化。结论脑内型表皮样囊肿的CT、MRI表现较具有特征性,尤其是MRI对其诊断有重要价值。     

颅骨表皮样囊肿的CT、MRI诊断

目的探讨颅骨表皮样囊肿(SEC)的CT、MRI表现特征。资料与方法搜集经手术、病理证实的9例SEC患者的影像学资料,分析其CT与MRI表现。结果CT平扫,病灶呈境界清楚的类圆形骨质破坏,无硬化边缘或见轻度硬化边缘;SEC多位于板障,内、外板膨胀,密度不均匀,CT值较低。MRI上多呈以长T1、长T2为主的混杂信号;扩散加权成像(DWI)上呈高信号。结论颅骨CT、MRI扫描发现有囊性膨胀生长及火山口样骨质缺损表现,对诊断具有重要意义,而DWI对SEC鉴别诊断有一定价值。     

第二鳃裂囊肿的MRI诊断价值探讨

目的:探讨BaileyⅡ型第二鳃裂囊肿在MRI上的特征表现,提高术前诊断的准确性。方法:回顾性分析11例经手术病理证实的第二鳃裂囊肿的MRI表现,其中6例行MRI增强扫描,总结其特征讨论其形成机制。结果:本组11例全部为BaileyⅡ型;MRI表现为薄壁、均质的囊性肿块,囊腔在T1WI上呈低、等、高信号(其中低信号7例,等信号2例,高信号2例),T2WI常呈等、高信号(等信号2例,高信号9例);DWI均呈等、高信号(等信号3例,高信号8例);囊壁强化或不强化,并发感染者囊壁增厚、强化;胸锁乳突肌受压向后外或向后移位,颈动脉间隙大血管向内或向后内移位,颌下腺受压移位;脂肪抑制序列可更清楚的显示病变与周围关系。结论:对于BaileyⅡ型鳃裂囊肿,磁共振图像具有明显的信号特征及部位特征,对术前及鉴别诊断有重要价值。     

Magnetic resonance imaging of arachnoid cysts

A retrospective review of magnetic resonance imaging (MRI)—computed tomography (CT) correlation was performed in 29 patients with arachnoid cysts. Short TR, short TE spin echo (SE) pulse sequences provided the best anatomic definition whereas multiple echo long TR, TE sequences allowed comparison of the signal intensity of the cyst with that of cerebrospinal fluid (CSF). Simple arachnoid cysts were isointense while neoplastic, hemorrhagic or inflammatory cysts were hyperintense relative to CSF. The CT differential diagnosis of an arachnoid cyst (depending upon its location) may include other cystic collections such as craniopharyngioma, epidermoid, astrocytoma, and chronic subdural hematoma. However, on MRI the combination of extraaxial location, morphological features, and signal intensity matching that of CSF allows one to make the diagnosis of an uncomplicated arachnoid cyst with confidence.