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1.
Soft tissue perineurioma is an uncommon benign peripheral nerve sheath tumor, although it is the most common subtype of perineuriomas. We present a case of soft tissue perineurioma in the left groin of a 48-year-old man. Precontrast computed tomography showed a homogeneous hypodense mass that showed faint enhancement. The mass appeared with hypointensity on T1-weighted magnetic resonance (MR) images and heterogeneous hyperintensity on T2-weighted MR images. Slight contrast uptake was noted on enhanced T1-weighted MR images with fat suppression. Although these CT and MR imaging findings were nonspecific, the overall imaging features are similar to those of schwannomas. 相似文献
2.
李文清 《实用医学影像杂志》2014,(2):101-103
目的:探讨磁共振成像(MRI)结合磁共振波谱成像(MRS)对大脑胶质瘤病的诊断价值。方法对15例经活体组织检查或手术病理证实的大脑胶质瘤病患者的临床表现及MRI平扫、增强,MRS影像学资料进行回顾性分析。MRI常规行T1WI、T2WI及FLAIR序列,采用时间飞跃法(TOF)的磁共振血管成像(MRA),T1WI增强扫描。氢质子MRS采用单体素STEAM序列,并分析N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱复合物(Cho)等物质峰值改变。结果所有病例均侵犯2个或2个以上脑叶,以颞叶、枕叶、胼胝体、基底节和丘脑等部位侵犯受累常见。病变区T1WI呈低或等低信号、T2WI呈高或混杂高信号、FLAIR上为高信号,未见明显坏死、钙化,受累区域脑组织肿胀,占位效应轻。注射钆喷酸葡胺增强扫描示10例无明显强化、3例斑片状强化、1例结节状强化、1例线状轻度强化。病变区域MRS表现为不同程度NAA降低,NAA/Cr比值降低;Cho上升,Cho/Cr和Cho/NAA的比值上升。结论 MRI结合MRS对大脑胶质瘤病的诊断及鉴别诊断具有临床价值,是目前诊断大脑胶质瘤病的首选影像学方法。 相似文献
3.
Pitfalls and limitations of magnetic resonance imaging in chronic posttraumatic osteomyelitis 总被引:3,自引:0,他引:3
The aim of this study was to evaluate pitfalls and technical limitations of MR imaging in diagnosing relapse of chronic posttraumatic
osteomyelitis of the lower extremities. Retrospective analysis of MR examinations in 15 patients (17 body areas) with suspected
relapse of chronic posttraumatic osteomyelitis (at least 1.5 years duration/mean number of surgical procedures per patient:
5.8). The MRI findings were compared with postoperative bacteriology (n = 11) and clinical follow-up (n = 4). Five patients had additional CT examination. Magnetic resonance imaging identified all infected areas correctly, but
five uninfected regions were diagnosed false positive due to postoperative scarring/oedema in bone defects (n = 4) and soft tissue (n = 1). Specificity of MRI in diagnosing active bone infection was 63 % and sensitivity 100 %. Additional CT was preoperatively
necessary in 5 patients (33 %) to further examine osteomyelitic and reparative bone remodeling. Metal artefacts were present
in 11 patients, rendering complete evaluation impossible (n = 2) or considerably more difficult (n = 4). Scarring/oedema in postoperative bone defects occurs up to 13 months postoperatively and represents a major pitfall
leading to low specificity. Definitive evaluation of suspected fistula, bony fragments and mineralization by MRI may be limited
in this special patient group and requires additional CT in one third of patients. Metal artefacts occur in most patients
and may impair or even prevent correct film evaluation in 23 and 11 %, respectively.
Received: 26 October 1999; Revised: 25 February 2000; Accepted: 11 April 2000 相似文献
4.
目的:通过对不同类型直肠肿瘤病例DWI图像分析和ADC值的测量探讨扩散加权成像对直肠肿瘤性病变的诊断价值。方法比较8例直肠腺瘤,30例中分化腺癌,6例低分化腺癌,7例黏液腺癌,6例淋巴瘤及5例间质瘤的ADC值的差异。结果①直肠淋巴瘤的ADC值明显低于直肠癌、直肠腺瘤,差异有统计学意义( P<0.05),淋巴瘤与间质瘤之间差异无统计学意义( P >0.05);②直肠腺瘤ADC值低于粘液腺癌( P <0.05),与间质瘤、腺癌之间差异无统计学意义( P>0.05);③间质瘤 ADC值低于粘液腺癌( P <0.05),与淋巴瘤、腺癌、腺瘤之间差异无统计学意义( P >0.05);④粘液腺癌ADC值高于中分化腺癌( P <0.05),与低分化腺癌之间差异无统计学意义( P >0.05),中分化、低分化腺癌之间差异无统计学意义( P >0.05)。结论扩散加权成像对不同类型直肠肿瘤、不同类别的直肠腺癌具有一定的鉴别诊断价值,联合MR常规扫描可提高诊断效能。 相似文献
5.
Magnetic resonance imaging and ultrasound are the imaging modalities recommended in the early diagnosis of Fournier's gangrene.
Because of the high mortality of this inflammatory disease early diagnosis is essential to initiate adequate surgical and
medical treatment. In the clinical literature only a handful of cases, in which diagnosis of Fournier's gangrene is based
on MRI findings, have been reported; therefore, we report another case which shows the ability of MRI especially to determine
the point of origin and extension of disease.
Received: 5 April 2000 Revised: 3 July 2000 Accepted: 4 July 2000 相似文献
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7.
胎儿泌尿生殖系统畸形在临床上较常见。MRI可很好地评价泌尿生殖系统畸形及伴随畸形。胎儿MRI常采用稳态自由进动(SSFP)﹑单次激发快速自旋回波(SSFSE)、快速T1WI以及扩散加权成像(DWI)等序列对泌尿生殖系统进行评价。综述MRI对胎儿肾脏畸形、梗阻性尿路疾病以及生殖系统畸形的诊断价值,并介绍各种胎儿畸形的MRI特征性表现。 相似文献
8.
The term glomangiomatosis refers to multiple glomus tumors, a rare condition. Unlike solitary glomus tumors, multiple glomus tumors are not always located in the subungual region, making diagnosis difficult. We report on three cases of glomangiomatosis in the foot, and describe their MR findings and review previous case reports on this subject. 相似文献
9.
The value of magnetic resonance imaging for the diagnosis of arrhythmogenic right ventricular cardiomyopathy 总被引:7,自引:0,他引:7
Maksimović R Ekinci O Reiner C Bachmann GF Seferović PM Ristić AD Hamm CW Pitschner HF Dill T 《European radiology》2006,16(3):560-568
This study evaluated the diagnostic significance of a magnetic resonance imaging (MRI) based scoring model for identification
of arrhythmogenic right ventricular cardiomyopathy (ARVC) in patients with MRI evidence of RV abnormalities. Fifty-three patients
with RV myocardial abnormalities on MRI were divided into a group with ARVC 1 (n=17) and a group with other RV arrhythmias (n=37). Decision tree learning (DTL) and linear classification (based on a modified ARVC scoring model of major and minor criteria)
were used to identify and assess MRI criterion information value, and to induce ARVC diagnostic rules. All major ARVC criteria
were more frequent in the ARVC group. Among minor criteria regional RV hypokinesia, mild segmental RV dilatation, and prominent
trabeculae were more frequent in the ARVC group while mild global RV dilatation was more frequent in the non-ARVC group. RV
aneurysm achieved highest importance in ARVC diagnosis (predictive accuracy 76.8%). Better diagnostic accuracy (sensitivity
93.3%, specificity 89.5%) was achieved when the MRI score for the major and minor criteria reached threshold value of four:
two major criteria, or one major and two minor, or four minor criteria. Combinations between major and minor criteria contributed
to a statistically valid model for ARVC diagnosis. 相似文献
10.
MRI与MRCP结合在胆管恶性梗阻性病变诊断中的应用价值 总被引:1,自引:0,他引:1
目的:探讨磁共振成像结合磁共振胰胆管成像技术对胆管恶性梗阻性病变的诊断价值。方法:收集30例经手术病理和临床治疗证实的胆管恶性梗阻性病例,回顾性分析其影像学表现。结果:30例患者MRI均表现为肝内外胆管不同程度阻塞性扩张。其中胆管癌23例,胆囊癌1例,肝细胞肝癌2例,转移瘤2例,壶腹癌2例。阻塞部位在肝内胆管部2例,肝门部10例,中部15例,壶腹部3例。所有病例均经临床或病理证实。结论:MRI与MRCP结合能显示胆管阻塞性扩张及阻塞部位,有较高的诊断价值。 相似文献
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The aim of this study was to compare contrast-enhanced electron-beam computed tomography (EBCT) and navigator-echo-based MRI of the coronary arteries in the same patient population. Both methods were assessed for visualization of the coronary arteries and their diagnostic accuracy in identifying significant coronary artery stenoses compared with conventional coronary angiography. Twenty patients with known coronary artery disease were examined with both contrast-enhanced EBCT and a respiratory-gated MRI sequence. A grading system was used to evaluate the image quality. Sensitivity and specificity for the detection of significant coronary artery stenoses was evaluated compared with conventional coronary angiography. With EBCT, 89% of the main coronary arteries could be completely visualised in the proximal and middle segments; with MRI, 83% were visualised. With EBCT the sensitivities for identifying significant (>/=50%) stenoses in proximal and middle vessel segments were 75% in the main stem, 88% in the left anterior descending coronary artery, 75% in the left circumflex coronary artery, and 90% in the right coronary artery. Respective sensitivities for MRI angiograms were 75, 82, 75 and 80%. With both modalities a sufficient image quality of the main coronary arteries can be obtained in most cases. The diagnostic capability for detecting significant stenoses is comparable for both methods. 相似文献
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Pitfalls of magnetic resonance imaging of alar ligament 总被引:6,自引:0,他引:6
An observational study of variations in the appearance of the alar ligament on magnetic resonance imaging (MRI) and the normal range of lateral flexion and rotation of the atlas was performed to validate some of the premises underlying the use of MRI for the detection of injuries to the alar ligament. Fifteen healthy volunteers were included. Three sets of coronal proton-density images, and axial T2-weighted images of the craniovertebral junction, were obtained at 0.5 T with the neck in neutral position and laterally flexed (coronal proton density) or rotated (axial T2). Five of the subjects also underwent imaging at 1.5 T. The scans were independently examined twice by two radiologists. The presence of alar ligaments was recorded and a three-point scale used to grade the extent of hyperintensity exhibited by the structures: the ligament were graded as 2 and 3 if, respectively, less or more of its cross-section was hyperintense, whereas grade 1 represented a hypointense ligament. The effect of lateral flexion on image quality was assessed. Concordance analysis of the data were performed before and after dichotomising the data on grading. The atlanto-axial angle and rotation of the atlas were measured. The magnitude of movement to right was normalised to that to the left to give, respectively, the flexion index and the rotation index. The alar ligaments were most reliably seen on coronal proton-density scans, with a Maxwells RE of 0.96 as compared with 0.46 for sagittal images. Flexion of the neck improved definition of the ligaments in only rare instances. Inter-observer disagreement was marked with respect to grading of the ligament on both coronal [composite proportion of agreement (p0)=0.44; 95% confidence intervals: 0.26, 0.64)] and sagittal scans [p0=0.40 (0.19, 0.63)]. Dichotomising the data did not appreciably improve reliability [Maxwells RE: –0.11 (coronal scans), –0.20 (sagittal scans)]: for ligaments which demonstrated hypertensive areas (grades 2 and 3) there was complete lack of agreement for both coronal [p2=0 (0, 0.25)] and sagittal scans [p2=0 (0–0.30)]. A large response bias was found in the reports of both readers albeit in opposite directions. There was poor concordance between scans obtained at different field strengths [RE (coronal images)=0.25; RE (sagittal images)=0.14). Mean flexion index and mean rotation index were 1.00 (SD 0.03) and 1.01 (SD 0.06), respectively. The MR imaging may not be the investigation of choice for the investigation of subtle injuries to the alar ligament. Whether it can be substituted by kinematic assessment of the occipito-atlanto-axial complex with MRI warrants investigation. 相似文献
14.
Schouman T Courvoisier DS Imholz B Van Issum C Scolozzi P 《European journal of radiology》2012,81(9):2251-2254
Objective
To evaluate the reliability, accuracy and rapidity of a specific computational method for assessing the orbital floor fracture area on a CT scan.Method
A computer assessment of the area of the fracture, as well as that of the total orbital floor, was determined on CT scans taken from ten patients. The ratio of the fracture's area to the orbital floor area was also calculated. The test–retest precision of measurement calculations was estimated using the Intraclass Correlation Coefficient (ICC) and Dahlberg's formula to assess the agreement across observers and across measures. The time needed for the complete assessment was also evaluated.Results
The Intraclass Correlation Coefficient across observers was 0.92 [0.85;0.96], and the precision of the measures across observers was 4.9%, according to Dahlberg's formula .The mean time needed to make one measurement was 2 min and 39 s (range, 1 min and 32 s to 4 min and 37 s).Conclusion
This study demonstrated that (1) the area of the orbital floor fracture can be rapidly and reliably assessed by using a specific computer system directly on CT scan images; (2) this method has the potential of being routinely used to standardize the post-traumatic evaluation of orbital fractures. 相似文献15.
目的:探讨平山病(hirayama disease)的MR影像学表现,提高对该病的认识。方法通过查阅相关文献,回顾性分析2例临床已确诊的平山病MR自然位和过屈位影像表现,观察其低位颈髓的动态变化,并与健康自愿者的同条件扫描影像相比较,总结平山病的MR影像学表现。结果①自然位:曲线多有异常,下段颈髓萎缩,髓内可有异常信号,有失连接现象;②过屈位:所有患者均出现颈髓前移、变扁,硬脊膜后有月牙形、集簇状异常信号影;③2例患者强化检查示过屈位脊膜后异常信号影有强化;④志愿者自然位扫描显示颈椎曲度自然,颈髓粗细均匀,不存在失连接现象,过屈位脊膜后无异常信号影。结论MR颈椎检查特别是过屈位扫描能够显示出平山病的特征性影像学改变,对于平山病的早期诊断具有重大价值。 相似文献
16.
Dynamic breast magnetic resonance imaging without complications in a patient with dual-chamber demand pacemaker 总被引:1,自引:0,他引:1
Sardanelli F Lupo P Esseridou A Fausto A Quarenghi M 《Acta radiologica (Stockholm, Sweden : 1987)》2006,47(1):24-27
Mammography and ultrasound indicated a cancer of the right breast in a 77-year-old woman with a dual-chamber demand pacemaker. The patient was not pacemaker-dependent. She underwent breast 1.5T magnetic resonance imaging (MRI) (dynamic gradient echo sequence with Gd-DOTA 0.1 mmol/kg). Before the patient entered the MR room, the configuration of the device was changed (the response to magnet was switched from asynchronous to off and the rate-responsive algorithm was disabled). No relevant modifications of heart rhythm or rate were observed during the MR examination. No symptom was reported. Immediately after the examination, the pacemaker interrogation showed neither program changes nor alert warnings. MRI detected a bifocal cancer in the right breast which allowed tailored breast-conserving treatment to be initiated. Histopathology confirmed a bifocal invasive ductal carcinoma. 相似文献
17.
Intraoperatively magnetic resonance (MR)-guided neurosurgical operations have been done since 1996, mostly for brain tumors. Several different concepts for intraoperative MRI procedures using low-, middle-, and high-field MR scanners have been reported from pioneering neurosurgical centers. In this article, we present the different solutions used in these centers from a practical point of view. More thoroughly, we present our own concept and experience of 160 craniotomies since 1999 in an operation theater equipped with a low-field (0.23T) scanner, which can be turned on and off during surgery. 相似文献
18.
目的 探讨CT、MRI检查在脑血管畸形诊断中的价值.方法 回顾性分析25例经临床或病理诊断的脑血管畸形CT和MRI资料,比较CT和常规MRI序列(T1 WI、T2 WI、FLAIR)、MRA及MRI磁敏感加权成像(susceptibility weighted imaging,SWI)的影像表现、检出率,判断其诊断价值.结果 25例病例中动静脉畸形16例、海绵状血管瘤7例和静脉畸形2例.16例动静脉畸形中3例CT平扫未见异常,13例CT平扫表现为边界不清的混杂密度影和迂曲扩张的血管影.而常规MRI和MRA上均可见扩张迂曲的异常血管团影.在SWI上均可见斑点状、迂曲的条状低信号影.7例海绵状血管瘤4例为单发,3例为多发,共检出病灶73个.CT平扫检出5例19个病灶.常规MRI检出51个病灶,“桑椹”状高低混杂信号及“铁环征”较具有特征性.在SWI像上检出病灶73个,其中69个为低信号,4个为以低信号为主的混杂信号.2例静脉畸形均为单发,CT平扫、常规MRI检查均无特异性表现,SWI表现为放射状异常信号影聚集,呈“水母头”征.结论 CT检查对合并急性出血、钙化的病灶敏感,但对无出血、无钙化及微出血的小病灶检出率低,定性困难.MRI常规序列结合SWI序列扫描能提供更多、更准确的信息,为诊断脑血管畸形的最佳检查方法. 相似文献
19.
磁共振成像在结肠检查中的诊断价值 总被引:1,自引:0,他引:1
磁共振结肠造影是元创、元辐射的诊断结肠疾病新型影像学检查方法。该方法可以准确发现大于8mm的结肠息肉。它不仅用于结肠癌的检出与准确分期,还可对结肠的炎性狭窄进行有效评价。与传统结肠检查方法相比,磁共振结肠造影具有自己独特的优势,可对任意平面图像进行多种后处理,尤其是仿真内镜的成像。本文就磁共振结肠造影的现状和发展前景进行探讨。 相似文献
20.
It is well known that bizonal histologic appearance characteristic of neurofibromas are reflected on magnetic resonance (MR) images. We report a case in which a delayed enhanced MR image showed that the entire mass enhanced homogeneously resulting in loss of zonal distinction on early enhanced MR image 相似文献