Three cases of alveolar soft part sarcoma and MRI findings

Three cases of alveolar soft part sarcoma were reported with characteristic MRI findings. On MRI findings, slightly higher signal intensity than muscles on T1 weighted image and remarkably high signal intensity on T2 weighted image were thought to be characteristic of alveolar soft part sarcoma.     

颅脑磁共振T1WI高信号病变影像诊断

目的：探讨颅脑MRI T1WI高信号病变影像表现,结合文献讨论其发生机制和病理改变。方法：回顾性分析63例颅脑MRI TIWI高信号病变的影像表现,包括脑出血、黑色素瘤、糖尿病脑病、缺血缺氧性脑病、亚急性期脑梗死、颅内囊肿及脂肪瘤。结果：脑出血T1WI以高信号为主,T2WI呈低或高信号,磁敏感加权成像（SWI）呈低信号;黑色素瘤T1WI呈高信号,T2WI呈等或低信号,无灶周水肿;糖尿病脑病可见双侧或单侧基底节区T1WI高信号,T2WI信号正常或轻度降低。脑缺血缺氧性疾病高信号主要位于侧脑室旁白质,弥散加权成像（DWI）呈高信号。亚急性期脑梗死高信号主要位于脑灰质,呈片状或脑回样高信号;颅内囊肿主要见于脑室内和鞍区,T1WI以高信号为主,T2WI呈高或/和低信号。脂肪瘤位于大脑镰旁,压脂像呈低信号。结论：含正铁血红蛋白、黑色素、脂质、蛋白及矿物质病变在T1WI上可呈高信号,熟悉这些病变化学组成及其对T1时间的影响有助于鉴别诊断。     

MR imaging of idiopathic transient osteoporosis of the hip

Four patients with idiopathic transient osteoporosis of the hip were examined by magnetic resonance imaging (MRI). MRI clearly showed low signal intensity in the affected femoral head on T1-weighted images and high signal intensity on T2-weighted images. After regression of hip pain, MR images became normal. MRI was a useful method for diagnosis and follow-up study of idiopathic transient osteoporosis of the hip.     

MRI imaging of liver neoplasma

MRI by 1.5 T imager with spin echo pulse sequence was performed on 53 liver neoplasms (13 hepatocellular carcinomas (HCC), 28 cavernous hemangiomas and 12 metastasis). Lobulated and notched contour were observed in 72% of our cases of hemangioma. It is well known that in hemangioma several kinds of echographic patterns appear, but in MRI, almost all hemangioma appear to show the same signal pattern as high intensity homogeneous on T2 weighted image. No liver neoplasma showed high intensity on T1 image except in 1/3 of cases of HCC. Contrast enhancement with Gd-DTPA is useful for differential diagnosis of liver neoplasma because it shows different signal patterns from the other diseases.     

MRI of an intrathoracic malignant tumor invading the chest wall

22 patients with intrathoracic malignant tumors suspected of invading the chest wall were examined with CT and MRI. Chest wall invasion was operatively confirmed in 19 cases and excluded in the other 3 cases. CT showed tumor infiltration of the chest wall in 14/19 cases, no morphological changes in 5/19 cases. Thoracic wall invasion was demonstrated by MR in all 19 cases. Typical MR finding of malignant invasion was local lesion within the chest wall showing high signal intensity in post-Gd T1-weighted images and in T2-weighted images. Reactive inflammatory changes as well as malignant infiltration of the pleura showed high signal intensity on enhanced T1-weighted images and on T2-weighted images.     

Difference between T1 and T2 weighted MR images in avascular necrosis of the femoral head

T1 and T2 weighted MR images were compared in 32 hips with avascular necrosis, and the difference between them was discussed. In 27 of 32 hips, abnormal low intensity area in the affected femoral head is smaller in T2 weighted images than in T1 weighted images. The area of low intensity on T1 weighted image and high on T2 weighted image might be granuloma in reactive tissue and surrounding hyperemia. The difference between T1 and T2 weighted images must be taken into consideration especially in determination of the border of affected bone.     

MRI对血精性精囊炎的诊断价值

目的分析血精性精囊炎的MRI表现，探讨MRI在血精性精囊炎诊断中的价值。方法回顾性分析了25例血精性精囊炎的MRI表现，观察其形态、大小及内部异常信号改变，分别采用SE T1WI(TR/TE558／14ms)，Flash 2D水激励T1WI(TR/TE18．5／5．2ms)，TSE T2WI(TR/TE 4000／99ms)加脂肪抑制序列扫描。结果本组25例血精性精囊炎均表现为两侧精囊体积增大；精囊内“出血”于SE T1WI呈斑片状／斑点状高信号，此高信号影于Flash 2D水激励T1WI序列显示更清晰，低信号精囊管道壁因高信号出血衬托而得以显示；精囊内“出血”于TSE T2WI呈相对较低信号，低信号精囊管道壁被较低信号出血影掩盖而显示不清。结论MRI能对血精性精囊炎做出明确诊断，是血精性精囊炎最可靠的影像学检查方法。     

骨质疏松与转移瘤所致急性椎体压缩的MRI鉴别诊断

目的 分析、总结骨质疏松与转移瘤所致的急性椎体压缩的MRI表现，评估MRI在两者鉴别诊断中的价值。材料与方法 根据临床表现、生化检查、普通X线照片及CT检查等随机选择骨质疏松及转移瘤各30例，每例均同时进行SE、T1W、FSE、T2W及SE、T1W增强检查。结果 总结了有助于急性椎体压缩鉴别诊断的11种MRI表现：提示为骨质疏松所致的有4种，其中压缩椎体后缘向前成角且骨片向椎管内突出为特异性表现；提示为转移瘤的有7种，其中硬膜外肿块、椎弓根骨质破坏、T1W增强扫描及T2WI呈弥漫性高信号或非均匀性信号为特征性表现。结论 在鉴别是骨质疏松还是转移瘤所致的急性椎体压缩中，MRI是一种敏感和可靠的检查方法。     

足底筋膜损伤的MRI诊断

目的评价足底筋膜损伤的MRI诊断价值。方法回顾性分析11例经手术病理和临床随访证实足底筋膜损伤患者的MRI与I临床资料,总结MRI表现特征。结果足底筋膜损伤的MRI表现有4种类型,（1）急性筋膜炎：T2WI、Stir足底筋膜内斑片状高信号,筋膜周围软性组织呈高信号改变。（2）慢性筋膜炎：T1wI足底筋膜呈纺锤形增厚,信号增高,筋膜附着部跟骨见骨性突起或局灶性皮质缺损。（3）筋膜完全断裂：T1WI、T2WI、Stir筋膜连续性中断,断裂部位呈高信号改变。（4）筋膜部份断裂：T1WI、T2WI、Stir筋膜连续性部份中断,断裂部分增厚,呈高信号改变。结论MR是诊断足底筋膜损伤的最好检查方法。     

四肢软组织肿瘤MRI影像特征分析

目的:探讨四肢软组织肿瘤的MRI特征,以提高诊断准确性.方法:收集经病理证实的四肢软组织肿块38例,分析其MRI征象.结果:38例软组织肿块包括良性肿块31例,恶性肿块7例.除脂肪瘤、脂肪肉瘤及血肿机化在T1WI、T2WI上表现为高信号外,其余肿块T1WI多为等或低信号,T2WI多为高信号或以高信号为主的混杂信号.良性组一般边界清楚,部分病变具有特征性MRI征象.恶性组体积较大,信号不均匀,其中6例邻近组织受侵.结论:MRI能清楚地显示肿瘤的范围、信号特征及与周围组织的关系.某些特征性MRI征象对软组织肿块的正确诊断及鉴别诊断具有重要意义.     

直肠癌MRI诊断及术前分期的价值

目的:探讨直肠癌MRI影像特征及术前分期价值。方法:回顾性分析32例全部经术后病理证实直肠癌患者MR资料。总结MRI影像特征并将影像资料与术后病理结果对照分析。结果:11例直肠癌表现为肠腔内软组织肿块,21例表现肠壁环状和新月形增厚,肠腔不规则性狭窄。T1WI等或稍低信号,T2WI稍高信号,DWI高或明显高信号,增强呈显著强化。术前分期与病理符合率为84.4%。结论:MR检查技术对直肠癌诊断及术前分期具有重要价值。     

High signal intensities on T1-weighted MRI as a biomarker of exposure to manganese

Increased signal in T1-weighted images was observed in the experimental manganese (Mn) poisoning of the non-human primate and a patient with Mn neurointoxication. However, our study showed that the increased signals in magnetic resonance images (MRI) were highly prevalent (41.6%) in Mn-exposed workers. Especially 73.5% of the welders showed increased signal intensities. Blood Mn concentration correlated with pallidal index. These changes in MRI tend to disappear following the withdrawal from the source of Mn accumulation, despite permanent neurological damage. Thus increased signal intensities on a T1-weighted image reflect exposure to Mn, but not necessarily manganism. Our study also showed that the concentration of Mn required to produce increased signal intensities on MRI is much lower than the threshold necessary to result in overt clinical signs of manganism. Increased signal intensities in the globus pallidus were determined by Mn accumulation in the animal experiment. All these results strongly suggest that signal intensities in T1-weighted MRI reflect a target site dose in a biologically-based dose-response model. At which increase of signal intensity, the progression of manganism from Mn exposure occurs, however, remains to be solved.     

3T超高场磁共振在小肝癌中的诊断价值

目的:讨论3T超高场磁共振在小肝癌疾病诊断中的应用价值。方法:选取2007年10月至2012年6月我科收治的23例经过病理证实的小肝癌患者的磁共振影像资料进行回顾性诊断分析,记录平扫及增强、延迟扫描的影像特点。结果:小肝癌的MRI平扫表现形式多样,整体上T1WI以低信号为主,T2WI以高信号为主;增强检查,动脉期高信号为主,增强延迟以低信号为主。结论:超高场强磁共振动态增强检查能够对平扫T1WI和T2WI上呈现等密度图像进行鉴别诊断,同时动态增强检查在动脉期可观察到病灶的异常灌注,判断示门脉受累情况。     

1,2-二氯乙烷慢性中毒性脑病的磁共振成像分析

目的 回顾分析10例1,2-二氯乙烷(1,2-DCE)慢性中毒性脑病的磁共振成像(MRI)影像学特征.方法 采用MRI对头部进行扫描,层厚8 mm,层距2 mm,行轴位及冠状位扫描,T1WI,T2WI,FLAIR成像.结果 10例病例脑白质均表现不同程度异常信号,T1WI低信号,T2WI高信号,FLAIR高信号.临床中毒表现为轻、中度时,MRI表现为广泛的脑自质异常信号、呈现症状与表现不一致.结论 1,2-DCE中毒性脑病均表现为脑白质不同程度信号改变,结合职业接触史具有特征性.

Abstract：

Objective To study the MRI features of 1,2-dichloroethane Chronic Toxic Encephalopathy of 10 cases. Method 10 cases were examined by MRI, slice thickness 8mm, layer from 2mm, axial and coronal line scan, T1WI, T2WI, FLAIR imaging. Results 10 cases show varying degrees of abnormal signal of white matters,low signal intensity on T1WI, high signal intensity on T2WI and FLAIR. MRI could also show extensive abnormal signal in cerebral white matter although the toxic manifestation is mild to moderate. Therefore the syptoms and the shows of MRI could be inconsistent. Conclusion Combined with a history of exposure, the show of varying degrees of abnormal signal of white matter in 1,2-dichroroethane Chronic Toxic Encephalopathy cases are characteristic.     

MRI of lymphedema using short-TI-IR (STIR)

Thirty four cases with lymphedema of the extremities were examined with MRI at 0.5 tesla. On T1-weighted image, the enlarged subcutaneous tissue and the subcutaneous trabecular structures were seen in all cases. Moreover, the trabecular structures in the enlarged subcutaneous tissue showed low signal intensity on T1-weighted image and high signal intensity on T2-weighted image in all cases. Additionally, in 12 of 15 cases examined by Short-TI-IR (STIR) image, the trabecular structures and fluid collections in the subcutaneous tissue were shown more definitely in high signal intensity than by T2-weighted image. We consider MRI using STIR is to be useful in the evaluation of edematous disease.     

Diagnostic imaging in neuro-Behçet's disease. Report of 5 cases

The authors report five patients with neuro-Beh?et's disease. Computed tomography showed low-density lesions with or without mass effect and contrast enhancement. Magnetic resonance imaging revealed scattered areas of high signal intensity on T2-weighted images, and iso or low signal intensity on T1-weighted images with enhancement after gadolinium injection. These lesions affected all the central nervous system structures with predilection to the brain stem, basal brain ganglia, internal capsula, subcortical and deep cerebral white matter. By its availability, computed tomography remains a precious tool for diagnosis and assessment of severity of neurological involvement. Brain magnetic resonance imaging reveals silent lesions on CT, specifies their exact topography, identifies lesional association reminiscent of neuro-Beh?et and contributes to the differential diagnosis with multiple sclerosis. CT and MRI permit the follow-up of lesions under treatment and evaluate prognosis.     

小儿流行性乙型脑炎的临床及MRI特征分析

目的探讨小儿流行性乙型脑炎（乙脑）的临床特点与颅脑MRI影像特征及其与预后的关系,为临床早期诊治提供依据。方法回顾性分析本院收治的145例流行性乙型脑炎患儿的临床及MRI资料。98例行0．35TMRI检查获得常规T1WI、T2WI及FLAIR序列,47例行1．5TMRI检查除采集常规序列外,还采集了DWI序列。分析脑部MRI表现：病灶累及的部位、范围和MRI信号特征。结果MRI平扫中106例（73．1％）发现脑实质异常信号影,其病灶不同程度的累及丘脑,87例同时累及中脑大脑脚,同时累及基底节、脑皮质及小脑受累分别为32例、43例和2例;15例累及脑白质。病灶表现为不同范围的T2WI高信号病变,T1WI多呈低信号,少数呈等信号。FLAIR上全部可见高信号灶,少数高信号灶中心可见低信号影。38例FLAIR显示脑实质异常信号灶较T2WI更多。DWI上28例可见脑实质高信号病灶,12例可见低信号病灶,7例在DWI及ADC图均呈等信号改变。1．5TMRI阳性率（87．2％）明显高于0．35TMRI（66．3％,X^2=7．06,P〈0．01）。结论MRI能显示乙脑患儿颅脑病变的部位及范围,累及丘脑及中脑大脑脚为其特征性表现。FLAIR及DWI对乙脑的早期诊断具有很高的价值。     

MRI findings of muscular sarcoidosis

MRI characteristics of number lesions were studied in eight patients with sarcoidosis proved by Ga scintigraphy. T2 weighted image in spin echo method and low flip angle method were employed. The localization of lesion detected by Ga scintigraphy was quite similar to that of lesions found by MRI, but lesions were more clearly detectable in MRI than Ga. MRI could identify anatomical localization of muscular lesions. Two characteristic MRI findings were observed; one was high intensity in the whole lesion, and another was high intensity in periphery with low intensity in central lesion. MRI is a useful tool for more accurate diagnosis of muscular lesions in sarcoidosis.     

卵巢子宫内膜异位囊肿的MRI诊断与病理分析

目的分析卵巢子宫内膜异位囊肿的MRI特征。方法回顾性分析26例共31个卵巢子宫内膜异位囊肿,全部病例均经手术及病理证实。结果手术及病理对照,经MRI诊断的卵巢子宫内膜异位囊肿中,有27个符合,4个不符合。在27个符合病例中,T1WI和T2WI均呈高信号者13个,T1WI呈高信号而T2WI呈等或低信号者7个,T1WI、T2WI均呈混杂信号7个。其中边缘毛糙、与周围组织分界不清17个,部分不清7个,边界清楚3个。结论①卵巢子宫内膜异位囊肿的MRI表现为:卵巢巧克力囊肿在MRI表现为T1WI、T2WI均为高信号或混杂信号,以中、高信号为主。②卵巢子宫内膜异位囊肿的MRI信号特点与其内部病理成份密切相关。     

快速恢复快速自旋回波联合分段采集消除腰椎扫描时的重复饱和伪影

目的探讨消除腰椎MRI检查时椎间盘多平面多角度T2WI序列出现带状低信号伪影的可行方法。方法应用SIEMENS AVANTO 1.5T磁共振扫描仪,对42例临床怀疑腰椎间盘突出患者行腰椎常规矢状位和横断位多角度多平面扫描,采用快速自旋回波（TSE）序列、快速恢复快速自旋回波（TSE-Restore）序列,并由3名高年资医师对图像质量进行评价。结果 2种方法都能完全消除伪影,且图像质量完全符合诊断要求。结论快速恢复快速自旋回波联合分段扫描技术是最优化消除饱和伪影的方法。