骶管脊膜囊肿的MR脊髓成像

为了解骶管脊膜囊肿(SMC)在MR脊髓成像上的表现及评价MR脊髓成像对SMC的诊断价值,作者研究10例病人,主诉后下背痛(5例)、单侧腿疼(4例)和腹痛(1例)。SMC的诊断由手术和MRI做出(各5例)。后者随后行手术被确诊为硬膜外脊膜囊肿。磁共振扫描仪为0.5T(9例)和1.5T(1例)。MR平扫包括自旋回波矢状位T_2WI(4000/120/2～4/5mm[TR/TE/NSA/层厚]),T_1WI(400～500/12～30/1～2/5mm)及横断位T_1WI(500～600/15～20/1～2/5～6mm)。MR脊髓成像分别选用2D和3D single-shot快速自旋回波扫描序列。2D MR脊     

3.0T MR脑灰质成像在脑灰质异位中的应用

目的 探讨3.0T MR脑灰质成像在脑灰质异位症中的诊断价值.方法 回顾性分析25例经临床及MRI检查确诊的脑灰质异位症病人的MRI资料,全部病人均行头颅MRI常规T1WI、T2WI序列,FLAIR序列和脑灰质成像检查.结果 25例中,病变为双侧14例,单侧11例,多病灶17例.室管膜下型13例,皮层下局灶型10例,其中2例病人室管膜下及皮层下局灶并存,皮层下弥漫型2例.1例病人并发多微小脑回畸形,1例病人同时伴有透明隔缺如.在病变显示方面,灰质成像明显优于T1WI、T2WI及FLAIR(χ2=21.16,P ＜0.05).结论 3.0T MR脑灰质成像对显示灰质异位病变的部位和范围具有重要价值.     

直肠癌初次分期MR扩散加权成像能检出淋巴结,但不能明确其性质

正目的探讨直肠癌初次分期MR扩散加权成像(DWI)检出淋巴结及区分其良恶性的能力。方法21例病人术前行1.5 T MRI检查(±术前5×5 Gy),检查序列包括T2加     

3.0T MR颈动脉成像技术

目的：探讨颈动脉“亮血”3D-TOF MRA配合“黑血”血管壁MR成像技术对血管病变显示的能力。方法：采用颈动脉专用表面线圈,对31例疑有颈动脉病变的脑卒中患者行MR多序列(“亮血”3D-TOF、“黑血”T1WI、T2WI)检查,并进行颈动脉狭窄程度和病变分类,比较“亮血”序列和“黑血”序列检测的阳性率。结果：31例受...     

3.0 T MR淋巴管成像的可行性研究

<正>本项研究的目的是确定和评价3.0T MR对比剂增强淋巴管成像(MRL)在检测和显示外周淋巴系统异常方面的意义。16例病人皮内注射二乙烯三胺五乙酸钆剂后行高分辨力3.0T MR检查,采用T1W-3D-GRE-(FLASH)序列(TR3.76ms/TE1.45ms/FA30°/体素0.8mm×0.8mm×0.8mm)。2名放射科医     

3D-CISS序列MR成像在血管压迫性三叉神经痛中的应用

目的　探讨三叉神经痛患者的神经血管解剖关系。方法　应用 3D -CISS序列并结合 3D -TOF血管造影及MPR重建技术对 49例三叉神经痛患者进行MR检查并部分与手术结果对照。结果　 (1) 13例手术患者中 ,10例 3D -CISS和 3D -TOF序列均显示血管压迫的患者经手术证实为动脉压迫 ,另 3例仅在 3D -CISS序列显示的压迫血管 ,手术证实为静脉压迫。 (2 ) 2 0例伴有上颌神经症状的病人有 18例 (90 % )在三叉神经根部内侧有压迫点 ;19例伴有下颌神经症状的病人有 15例 (79% )在三叉神经外侧有压迫点 (经 χ2 检验 ,P <0 .0 0 1)。结论　 3D -CISS序列对显示三叉神经痛病人的神经血管关系、三叉神经的压迫部位与三叉神经痛区域相关性有重要作用。     

半月板撕裂关节内窥镜修补术后的MR和关节造影表现

作者对29例曾行内窥镜修补的半月板(男27例,女2例,手术时平均年龄24.5岁)及1例撕裂后行保守治疗的半月板(共30例)行MR检查,其中23例可与关节造影比较。MR检查应用1.5T超导型设备,采用自旋回波冠状序列T_1加权和矢状序列质子密度及T_2加权成象。半月板按Crues等的分类法分为:“0级”:正常;“1级”:半月板内灶性信号;“2级”:半月板内线形或楔形信号;“3级”:延至关节面的线形或球形信号。如果无延及关节面的线形信号说明半月板已愈合(0、1或2级),如果质子密度或T_1加权象上呈3级信号延及关节面应诊断半月板持续撕裂(未愈合),若     

自旋回波EPI MR弹性成像与梯度回波MR弹性成像评价疑似肝病儿童和青年病人的肝脏硬度

正摘要目的对比二维梯度回波(2D GRE)和二维自旋回波-平面回波成像(2D SE-EPI)MR弹性成像在测量疑似肝病儿童和青年病人肝脏硬度中的应用。材料与方法本研究经机构伦理委员会批准并符合HIPAA,58例病人在1.5 T屏气状态下行2D GRE和2D SE-EPI MR弹性成像检查。5名医师采用盲法测定肝脏硬度(平均值;k Pa)。采用配对t检验分别比较平均肝硬度和兴趣区(ROI)大小。采用组内相关系数(ICC)评估不同技术之间的一致性,Fisher确切概率检验进行序列之间呼吸运动伪影的比较。结果病人平均年龄     

非增强SSFP MR血管成像与常规增强MR血管成像对于胸主动脉疾病的成像质量和诊断准确性的对比性研究

<正>目的评价三维(3D)非增强稳态自由进动序列(SSFP)MRA对胸主动脉疾病的影像质量和诊断准确性。方法应用1.5T MR设备对50例确定或怀疑为胸主动脉疾病的病人行胸部自由呼吸心电门     

脑动静脉畸形的7T非增强MR成像

正摘要目的前瞻性评估7 T MR时间飞跃(TOF)MRA和7 T非对比增强磁化准备快速梯度回波(MPRAGE)对颅内动静脉畸形(AVM)显示,并与1.5 T TOF MRA以及DSA做对比分析。方法招募20例具有单个或者多个AVM的病人,研究方案包括7 T和1.5 T的TOF MRA,以及7 T的非对比增强MPRAGE序列,另外所有的病人都进行了4支血管的3D DSA检查。由2名放射科医生使用5点量表分析AVM以下     

MR arthrography

Review article on MR arthrography: technique and main indications. Intra-articular injection of diluted Gadolinium provides good distension and better appreciation of intra-articular structures than standard MRI. It is useful for partial tears of the rotator cuff, in cases of gleno-humeral instability, lesions of the acetabular labrum and hyaline articular cartilage and also for elbow, wrist and ankle ligamentous ruptures.     

Comparison study of indirect MR arthrography and direct MR arthrography of the shoulder

Objective  To compare the diagnostic value of indirect magnetic resonance arthrography (I-MRA) with that of direct MR arthrography (D-MRA) for labral tears, rotator cuff tears, and long head of biceps tendon (LHBT) tears using a 3-T MR unit. Materials and methods  Institutional review board approval was given; written informed consent was obtained from all patients. From November 2005 to June 2006, 19 patients (eight men and 11 women; mean age, 51 years) who had undergone both I-MRA and D-MRA underwent arthroscopic surgery. Both methods were performed in fat-saturated axial, coronal oblique, and sagittal oblique T1-weighted sequences, as well as axial and coronal oblique T2-weighted sequences. Two radiologists independently and retrospectively evaluated two sets of MRA for the diagnosis of superior and anterior labral tears, subscapularis tendon (SSC), and supraspinatus–infraspinatus tendon (SSP–ISP) tears, and LHBT tears. With the arthroscopic finding as a gold standard, we analyzed statistical differences of sensitivities and specificities between two sets of MRA and inter-observer agreement was evaluated using the kappa value. Results  The sensitivity and specificity of I-MRA and D-MRA for reader 1 were 79/80% and 71/80%, respectively, for superior labral tears; 100/100% and 100/100%, respectively, for anterior labral tears; 64/75% and 64/100%, respectively, for SSC tears; 100/86% and 100/100%, respectively, for SSP–ISP tears; and 67/100% and 78/100%, respectively, for LHBT tears. Those of I-MRA and D-MRA for reader 2 were 86/80% and 71/100%, respectively, for superior labral tears; 100/83% and 100/100%, respectively, for anterior labral tears; 64/88% and 82/100%, respectively, for SSC tears; 92/86% and 100/100%, respectively, for SSP–ISP tears; and 78/90% and 89/100%, respectively, for LHBT tears. No significant differences were found between the methods. Inter-observer agreements were higher than moderate (κ > 0.41) with both methods. Conclusions  Based on a relatively small number of patients, no significant difference was detected between I-MRI and D-MRI with regard rotator cuff, labral, and LHBT tears.     

Technical errors in MR arthrography

This article discusses potential technical problems of MR arthrography. It starts with contraindications, followed by problems relating to injection technique, contrast material and MR imaging technique. For some of the aspects discussed, there is only little published evidence. Therefore, the article is based on the personal experience of the author and on local standards of procedures. Such standards, as well as medico-legal considerations, may vary from country to country. Contraindications for MR arthrography include pre-existing infection, reflex sympathetic dystrophy and possibly bleeding disorders, avascular necrosis and known allergy to contrast media. Errors in injection technique may lead to extra-articular collection of contrast agent or to contrast agent leaking from the joint space, which may cause diagnostic difficulties. Incorrect concentrations of contrast material influence image quality and may also lead to non-diagnostic examinations. Errors relating to MR imaging include delays between injection and imaging and inadequate choice of sequences. Potential solutions to the various possible errors are presented.     

MR arthrography: anatomic-pathologic investigation

To enhance the efficacy of magnetic resonance (MR) imaging in evaluating articular soft-tissue structures, arthrography was performed before imaging 45 fresh cadaveric specimens. Contrast agents used were gadolinium-DTPA, 0.9% saline, diatrizoate, and air. MR imaging was performed with and without intraarticular contrast material, and specimens were subsequently sectioned in the same plane. Gd-DTPA was the most effective agent. Saline and diatrizoate exhibited equivalent signal behavior and necessitated T2-weighted sequences, while air was not useful. Depiction of normal anatomy was enhanced with MR arthrography. After surgical creation of lesions in selected specimens, subtle tears were delineated exclusively with MR arthrography, and major tears were diagnosed more confidently. Intraarticular contrast material may enhance the diagnostic capabilities of MR imaging in the setting of joint disease.     

MR imaging and MR arthrography of paraglenoid labral cysts

OBJECTIVE: We investigated the pathophysiology of paraglenoid labral cysts on the basis of MR imaging, MR arthrography, and cyst aspiration. MATERIALS AND METHODS: From 2211 MR imaging examinations, 51 (2.3%) cysts in 46 patients were identified. MR arthrography (n = 5), cystography (n = 1), arthroscopy (n = 17), percutaneous needle aspiration (n = 4), and medical records were also reviewed (n = 46). RESULTS: On MR imaging and arthrography, cysts were best viewed on T2-weighted images. Mean cyst diameter and volume were 2.2 cm and 2.8 cm3, respectively. Fifty-seven percent of cysts were located adjacent to the posterior labrum. On MR imaging and arthroscopy, a labral tear was identified in 27 (53%) and 15 (88%) patients, respectively. Eight cysts that caused compression neuropathy were large (mean size, 3.1 cm; p = 0.04) and located next to the posterior or inferior labrum. In four of five patients, MR arthrograms showed no intraarticular contrast material in the cyst. Cystograms showed no communication with the glenohumeral joint space, and cyst aspiration resulted in temporary symptom relief; however, cysts recurred in three of four patients. CONCLUSION: Most paralabral cysts are associated with labral tears. Paralabral cysts may be difficult to identify on MR arthrography unless a T2-weighted sequence is performed. Direct communication between a cyst and joint space rarely occurs. A posterior or inferior cyst may cause compression neuropathy of the suprascapular or axillary nerve, respectively. Cyst aspiration may result in temporary relief of symptoms, but an untreated labral tear should be suspected if cysts recur.     

MR arthrography of the hip joint

MR arthrography of the hip joint is usually performed after a conventional MRI has been obtained to rule out other pathologies of the hip joint as for instance bone marrow edema or osteonecrosis of the hip. MR arthrography is mainly performed as a very special investigation, and it is executed in most cases if the clinician asks for the diagnosis of a labral lesion. In very rare cases, MR arthrography of the hip is performed to image cartilage disease or osteochondrosis dissecans or free intraarticular bodies. In this paper, the indications, the technique, and the most important pathology of the hip joint--labral lesions--will be described as well as variants of the normal acetabular labrum. After a conventional MRI of the hip joint has been performed, a MR arthrography of the hip will be obtained to search for labral pathology or cartilage disease. MR arthrography is obtained after the intraarticular injection of 10-20 ml of a 0.1 mmol solution of gadopentate-dimeglumine has been performed. The intraarticular injection can either be fluoroscopic-guided or CT-guided or directly MR-guided. After the intraarticular injection, MR arthrography will be performed by the use of paracoronal and parasagittal T1-weighted spin echo or gradient echo sequences. In cases of labral lesions (degeneration, labral tear, labral detachment) or cartilage disease MR arthrography proved to be more sensitive as conventional MRI as shown in the literature. The sensitivity of MRI to detect labral pathology was reported to be about 65%, and that of MR arthrography was reported to be about 92-95% compared to surgical results. According to the current literature, MR arthrography is the most sensitive method to delineate these kind of pathologies. Therefore, the invasive technique of MR arthrography may be justified for the correct diagnosis of these kind of pathologies after other pathologic entities have been ruled out by conventional MRI.     

MR arthrography of the lower extremity

MR arthrography by virtue of its ability accurately to demonstrate intra-articular structures and abnormalities of these structures has become an important tool for the evaluation of a variety of articular disorders. Although not necessary in all patients, MR arthrography may facilitate the evaluation of patients with suspected intra-articular pathology in whom conventional MRI is not sufficient for an adequate therapy planning. MR arthrography combines the advantages of arthrography, like joint distention and delineation of intra-articular structures, with the superior spatial resolution of MRI. This technique improves diagnostic confidence, particularly in the assessment of subtle lesions and of complex anatomic structures. MR arthrography is of high value in the evaluation of osteochondral defects, loose bodies, previously operated menisci, and acetabular labral lesions.