磁共振二维扰相梯度回波小角度激励序列在半月板损伤中的诊断价值

目的探讨磁共振二维扰相梯度回波小角度激励序列（FLASH-2D）在半月扳损伤中的诊断价值．方法回顾性分析55俐膝关节半月板损伤的磁共振与关节镜资料．．磁共振均行SE序列T1WI、PD＋T2WI矢状位和冠状位扫描及FLASH-2D序列矢状位扫描。以关节镜为标准，对比半月板损伤在磁共振各种成像序列中的显示情况。结果本组关节镜检查诊断半月板损伤51例，SE序列T1WI、PD＋T2WI正中矢状位和冠状位诊断半月板损伤45例．敏感性为78％．特异性为90%；FLASH-2D序列矢状位诊断半月板损伤49例，敏感性为90％，特异性为97％。结论FLASH-2D序列矢状位与SE序列T1WI、PD＋T2WI正中矢状位和冠状位相比，具有更高的敏感性和特异性，在半月板损伤中具有更高的诊断价值。     

膝关节的磁共振成像技术与临床应用探讨

目的 探讨膝关节的磁共振成像技术与临床应用价值.方法回顾性分析60例关节镜或骨科手术确诊的膝关节病变MRI影像资料,扫描序列包括矢状位、冠状位、横断位T2WI/SPIR 及矢状位T2WI、T1WI、T2WI/FFE.结果优片率达85%以上.T2WI/FFE序列诊断半月板撕裂或变性30例,关节软骨损伤20例,均优于T2WI/SPIR、T2WI/TSE、T1WI/TSE序列,P值均小于0.01;T2WI/SPIR 诊断膝关节挫伤20例,侧副韧带损伤10例,均优于T2WI/FFE、T2WI/TSE、T1WI/TSE序列,P值均小于0.01;交叉韧带损伤,各序列之间差异性无统计学意义,P值大于0.01.结论膝关节MRI扫描中采用多方位成像、多序列组合,从而准确诊断膝关节损伤的程度、大小、范围,为临床制定正确的治疗方案提供可靠、直观的依据.     

MRI不同序列在骨挫伤诊断中的应用价值

[目的]探讨MRI不同序列在骨挫伤诊断中的应用价值。[方法]对2006年8月～2006年12月间的45例骨挫伤患者行MRI检查，MRI扫描前均经CR、DR或CT扫描证实没有发生骨皮质的断裂与移位。临床主要表现为局部肿胀、疼痛及活动受限。使用SiemensNovus1．5T超导MRI机器，脊柱扫描使用肢体线圈，膝关节扫描使用膝关节线圈，行矢状位、冠状位及横断扫描。扫描序列包括自旋回波序列（SE）T1WI、快速自旋回波序列（TSE）T2WI、梯度回波序列（FL2D）T2WI、脂肪抑制序列T2WI。[结果]自旋回波序列（sE）T1WI检出44例，检出率为97．7％，快速自旋回波序列（TSE）T2WI检出37例，检出率82．2％，梯度回波序列（FL2D）T2WI检出24例，检出率75％，脂肪抑制序列T2WI检出45例，检出率100％。骨挫伤检出率脂肪抑制序列T2WI高于TSET2WI（P〈0．05），TSET2WI高于FL2DT2WI（P〈0．05）。骨挫伤高场MRI信号改变主要表现为T1WI呈低信号，rISET2WI呈等高信号，FL2DT2WI呈混杂稍高信号，脂肪抑制序列T2WI呈明显高信号。边界不清，信号不均匀。[结论]对于骨挫伤脂肪抑制序列T2WI检查好于TSET2WI及FL2DT2WI，与SE T1WI相结合能够更敏感的发现骨挫伤改变。     

Ⅰ型先天性胆管囊肿及合并症的MR诊断与术前评估

目的探讨磁共振(MR)对Ⅰ型先天性胆管囊肿及其合并症的诊断及术前评估价值。方法回顾分析13例Ⅰ型先天性胆管囊肿及合并症的MR影像特点,并与手术结果比较。MR检查序列包括轴位T2WI、T1WI平扫,真稳态自由进动快速成像序列(true-FISP)冠状面扫描,2D-MRCP和轴位Gd剂增强T1WI扫描。结果13例患者均表现为胆总管呈囊状扩张。①6例合并结石及感染,表现为囊壁均匀增厚和明显强化,囊肿内结石影。②合并胆管癌7例,其中4例以胆管壁不规则增厚为主要表现,3例表现为腔内的软组织肿块;6例一期手术切除,1例因广泛局部浸润而行姑息手术治疗。13例的MR影像特点与手术结果完全相符合。结论MR不仅能清晰显示先天性胆总管囊肿,而且还能准确诊断其合并症。     

磁共振腰骶椎矢状位Dixon序列对急性腰腿痛的诊断价值

目的探讨磁共振腰骶椎矢状位Dixon序列对急性腰腿痛患者的临床诊断价值。方法纳入急性腰腿痛患者230例,行腰骶椎磁共振检查,扫描序列包括：矢状位Dixon、TSE T2WI、TSE T1WI,横轴位TSE T2WI,比较分析矢状位Dixon序列和矢状位TSE T2WI序列在急性腰腿痛患者中的阳性检出率。结果矢状位Dixon序列检出病变的敏感性显著高于矢状位TSE T2WI（P〈0.05）。结论磁共振腰骶椎矢状位Dixon序列对急性腰腿痛患者的诊断效能高,能敏感地显示常规T2WI序列难以显示的病变。     

MR在脊椎新旧骨折鉴别诊断中的作用

目的探讨MR在脊椎新旧骨折鉴别诊断中的意义。方法对137例脊椎骨折的病人进行MR多序列扫描,与临床和司法认可相对照,总结新旧骨折在各序列中的表现。结果137例中177个椎体骨折,其中141个椎体是新鲜骨折,36个椎体是陈旧性骨折。新鲜骨折典型表现:骨折线T1WI呈稍低信号,T2WI呈高信号。周围骨髓水肿呈T1WI稍低信号,T2WI呈稍高信号,可伴有软组织肿胀、椎间盘及脊髓损伤。陈旧性骨折典型表现T1WI和T2WI椎体信号与正常椎体一致,或骨折线T1WI及T2WI呈低信号,T2WI脂肪抑制序列呈低信号。结论MR多序列扫描可以做出脊椎骨折是新鲜骨折或陈旧骨折的诊断,使司法鉴定更加公正、合理、合法。     

前交叉韧带损伤:3.0TMR影像与关节镜对照分析

目的分析膝关节前交叉韧带损伤的3．0TMRI特征,并与关节镜手术结果对照。方法回顾性分析来我院行3．0T MR膝关节检查的36例前交叉韧带损伤患者的40个膝关节,全部病例经关节镜检查确诊。应用3．0T MR机（Philips Achieva型）,膝关节专用线圈,进行斜矢状位TSE T1WI、TSE T2WI、PD-SPIR和冠状位、轴位TSE T2WI扫描。前交叉韧带损伤分为完全断裂、撕裂（部分断裂）及胫骨端撕脱。将膝关节前交叉韧带损伤的3．0T MR影像特征与关节镜手术结果进行对照分析。结果前交叉韧带完全断裂MRI直接征象表现为韧带连续性中断,断端肿胀（21／25）,间接征象为交叉韧带过度弯曲、T2WI和PD-SPIR股骨髁间窝外侧骨挫伤;MRI与关节镜诊断完全符合率为84．00％。前交叉韧带撕裂（部分断裂）MRI直接征象为ACL矢状T2WI和PD-SPIR显示形态不规则、部分撕裂,ACL局部肿胀增粗,信号增高,仍可见连续存在的纤维低信号;MRI与关节镜诊断完全符合率为66．67％。前交叉韧带胫骨端撕脱MR检查直接征像为胫骨近端可见T1WI、T2WI低信号撕脱骨片（3／3）,ACL水肿、形态不规则,周围可见出血、积液,MRI与关节镜诊断符合率为100％。结论高场强3．0TMR膝关节诊断的多平面、多序列影像相结合可形成ACL立体影像观,结合临床能够有效诊断ACL损伤。     

急性胰腺炎MRI诊断的临床研究

目的探讨MRI对急性胰腺炎的诊断价值。方法选择经临床确诊的急性胰腺炎患者68例,且全部进行过MRI检查,均采用了轴位的SE序列T1WI,FSE序列T2WI,脂肪抑制序列STIR,冠状位的SE序列T1WI,全部病例进行了MRCP检查。结果 MRI主要显示胰腺肿大,胰腺周围渗出,腹腔内可见积液,STIR序列显示周围渗出更具有优越性;MRCP显示胆总管扩张,胰腺管不规则扩张。结论 MRI对急性胰腺炎的诊断具有重要的诊断价值,STIR序列的应用更具有优越性。     

MRI诊断青少年运动员慢性肘关节运动损伤：成像序列的选择

目的探讨MRI诊断青少年运动员慢性肘关节损伤的价值以及成像序列的选择。方法以34名6-16岁运动员的40个肘关节作为研究对象,分别采用矢状位、冠状位及轴位MR扫描,分析图像特点。结果应用轴位T1W、矢状位T1W、T2W、STIR、PDW等序列明确显示肘关节软组织和骨骼解剖及其病变;矢状位T2W、STIR等序列能很好显示关节腔积液、骨膜增厚,PDW序列对骨质损伤、韧带受损及滑膜炎显示较好。结论 MRI可很好地显示青少年运动员慢性肘关节损伤的关节内、外骨骼肌肉组织受损情况;选择适当的成像序列是充分显示病变的基础。     

原发颈胸段骨肿瘤的MRI诊断及临床意义

目的：分析原发颈胸段骨肿瘤的MRI表现。材料与方法；采用美国GE公司2.0tsl扫描仪，扫描序列包括，矢状位，冠状位，横轴位T1WI。选择26例经术后病理和临床证实的颈胸段肿瘤，分别观察椎体，附件，椎间盘病变情况。椎体溶骨及软组织肿块MRI情况。结果：颈胸段原发肿瘤溶骨破坏均为T1WI高信号，软组织阴影T2WI为高信号，各种肿瘤又有不同影表现。结论：MRI对颈胸段原发肿瘤具有订前判断诊断价值。     

基于中国数字化人体的肩袖间隙薄层断面解剖与MRI对照研究

目的探讨基于中国数字化人体(CVH)和MRI对照,观察肩袖间隙(RI)薄层断面解剖特点,为临床应用提供影像解剖学依据。方法获取5个CVH肩关节解剖数据集,以斜冠状位、斜矢状位虚拟重建显示RI连续薄层断面解剖,并与20侧肩关节MR平扫T1WI,5侧肩关节MR造影(MRA)对照,用PhotoShop CS2软件观察RI。结果 3种显示方法中,CVH显示RI各边界最佳,优于MRI平扫T1WI和MRA。3个显示平面中,斜矢状位显示RI各边界结构及内容物最佳。在RI各边界显示中,其下界肩胛下肌腱、内界喙突在轴位、斜矢状位及斜冠状位3个平面中及CVH、平扫T1WI、MRA 3种显示方法中最易清楚显示。结论基于CVH的数据集研究RI边界及毗邻关系是较好的方法,以其斜矢状位显示肩袖间隙边界、内容物及毗邻关系为最佳,为肩袖间隙疾病影像诊断提供了重要的识别标志。     

Comparison of prognostic value of different MRI classifications of signal intensity change in cervical spondylotic myelopathy

Background ContextSignal intensity (SI) changes of the spinal cord on magnetic resonance imaging (MRI) in cervical spondylotic myelopathy (CSM) are thought to be a predictor of surgical outcome. However, the clinical significance of SI change remains controversial. Although several classifications exist for SI change, there are no previous studies comparing their prognostic significance.PurposeTo determine the MRI classification of SI changes in patients with CSM that is useful for prognostication of surgical outcome.Study DesignRetrospective case study.Patient SamplePatients who underwent cervical laminectomy for CSM between the time period of January 2000 and December 2005.Outcome MeasureClinical outcome was measured by the recovery rate (RR) and the postoperative Nurick grade.MethodsWe retrospectively studied 35 of the 77 CSM patients (mean age, 57.8 years; range, 30–69; preoperative symptom duration, 9.3 months) who underwent cervical laminectomy and who met the inclusion criteria. Postoperative MRIs were performed at a mean of 51.3 months postsurgery to assess for resolution of preoperative signal changes. The pattern of spinal cord SI was classified in three different ways: based on high SI on T2-weighted images (T2WI) (Grade 0—absent, Grade 1—obscure, and Grade 2—intense); based on the extent of SI change on T2WI into focal (confined to one disc level) and multisegmental (more than one disc level); and based on T1-weighted image (T1WI) and T2WI changes into Group A (MRI normal/normal), no intramedullary SI abnormality on T1WI or T2WI; Group B (MRI normal/high SI), no intramedullary SI abnormality on T1WI and high intramedullary SI on T2WI; Group C (MRI low/high SI changes), low-intensity intramedullary signal abnormality on T1WI and high-intensity intramedullary signal abnormality on T2WI. Preoperative clinical findings and MRI abnormalities were correlated with outcomes (Nurick scores, RR) after surgical intervention.ResultsPreoperative MRI studies demonstrated the following: Grade 0=1, Grade 1=13, Grade 2=13; focal=18, multisegmental=16; Group A=1; Group B=29; and Group C=5. Resolution of signal changes in T2WI was seen in most patients; however, four patients developed low SI in T1WI in the postoperative MRI. There was no significant difference in the RRs of patients with different grades in the T2WI or with focal or multisegmental SI changes (p=.47 and .28, respectively). In contrast, patients with low SI changes in T1WI were associated with a poor surgical outcome (p<.001). The linear regression model performed using low-intensity signal changes as a dependent variable and the RR as an independent variable confirmed the significance (p<.001) of low SI changes on T1WI as a predictor for surgical outcome.ConclusionsA classification system of MRI signal changes that accommodates both T1WI and T2WI is more predictive of surgical outcome than those that include T2W SI changes alone. Postoperative MRI is useful to identify late onset of low T1W intensity changes in patients with poor neurological recovery.     

Magnetic resonance microneurography of rabbit sciatic nerve on a 1.5-T clinical MR system correlated with gross anatomy

This study was performed to investigate the feasibility and accuracy of magnetic resonance (MR) microneurography of the rabbit sciatic nerve on a 1.5-T clinical MR system by correlation with the gross anatomy. The 3D T2-weighted imaging (3D-T2WI), 3D T2-weighted imaging plus spectral presaturation with inversion recovery (SPIR), and T1-weighted imaging (T1WI) of the sciatic nerve in ten rabbits were performed on a 1.5-T MR system. The radiological anatomy of the sciatic nerve was observed and correlated with the gross anatomy. The anterior-posterior diameter of the sciatic nerve trunk was measured on 3D T2WI and on gross anatomy. The T1 and T2 relaxation times were also measured with multiecho spin echo and mixed sequence, respectively. The tibial nerve and peroneal nerve in the sciatic nerve trunk in all ten rabbits could be clearly displayed on T2WI and T2WI. The fine branches of the gastrocnemius nerve, posterior femoral cutaneous nerve, and the posterior gluteal nerve could be clearly depicted on T2WI. The T1 and T2 relaxation times of the sciatic nerves were 915 and 40 ms, respectively. The anterior-posterior diameter of sciatic nerve trunk was measured grossly, and on T2WI was 3.17 +/- 0.21 mm and 3.15 +/- 0.19 mm, respectively. There was no statistically significant difference (t = 0.768, P = 0.462). With the 1.5-T clinical MR system, the microneurography of the sciatic nerve could be revisualized, and the finer structure of the sciatic nerve trunk could be clearly and accurately delineated.     

Relevance of magnetic resonance imaging for ventricular endoscopy.

OBJECTIVE: Endoscopic procedures may represent an alternative to microsurgery or shunt operations in intra- or paraventricular pathologies. However, the operative results mainly depend on the selection of suitable patients. In the present study of 30 patients with occlusive hydrocephalus, the relevance of differentiated magnetic resonance (MR) imaging for evaluation of the pathophysiological and anatomic prerequisites was investigated. PATIENTS AND METHODS: Apart from conventional axial T(2) -weighted turbo spin echo (TSE) sequences (TR/TE 2126/100 ms) and T(1) -weighted spin echo (SE) sequences (TR/TE 450/15 ms) with and without the administration of Gd-DTPA, the MR protocol included sagittal and coronal thin-sliced T(2) -weighted TSE sequences, cardiac-triggered (TR/TE > 2700/120 ms, slice thickness 3.0 mm) or in volume technique (TR/TE 4000/180 ms, slice thickness 1.4 mm). For the visualization of CSF flow, a sagittal and axial phase-contrast-multi-heart-phase (PCMHP) measurement with 16 phases per cardiac cycle and flow sensitivity in the cranio-caudal direction (TR/TE 18/9.5 ms and 14/9.5 ms) was performed. RESULTS: The combination of imaging and flow sequences provided most information about the extent and the etiology of hydrocephalus. An obstruction of CSF pathways could be detected by the absence of flow voids in T(2) -weighted TSE sequences or of flow signals in PCMHP sequences. The size of the foramen of Monro and of the third ventricle could be evaluated in thin-sliced T(2) -weighted TSE sequences, for the foramen of Monro in coronal and sagittal and for the third ventricle in coronal and axial slice direction, respectively. The basal structures of the third ventricle, including its floor, the infundibular recess, the mamillary bodies, and the basilar artery, could be best identified in sagittal thin-sliced T(2) -weighted TSE scans, cardiac-triggered or in volume technique. CONCLUSION: In occlusive hydrocephalus, a differentiated MR protocol with thin-sliced T(2) -weighted TSE sequences and phase-contrast sequences allows a very precise estimation of the pathophysiological and the anatomic prerequisites for endoscopic procedures. Furthermore, MR imaging can be used for the follow-up documentation of ventriculo-cisternostomies, -cytostomies, or openings of other membranes.     

Diagnosis of transitory osteoporosis of the hip and its imaging in magnetic resonance tomography

Magnetic resonance (MR) imaging may distinguish transient osteoporosis of the hip from more severe hip diseases. 12 patients with transient osteoporosis of the hip underwent MR imaging. The initial and follow-up studies included T1- and T2-weighted images in coronal, transverse or sagittal planes. There were revealed 3 stages: diffuse-, focal-, and residual stage. This syndrome is characterized by hip pain, limping, and osteoporosis of the femoral head with preservation of the joint space. The clinical symptoms and abnormalities on MR images disappeared completely within 6-10 months.     

The role of magnetic resonance imaging in the management of traction injuries to the adult brachial plexus

Magnetic resonance imaging (MRI) of the cervical spine and brachial plexus was performed on 26 consecutive patients presenting with traction injuries of the brachial plexus during 1996 and 1997. These included T1 and T2 weighted coronal, sagittal and axial images of the cervical spine and coronal images of the brachial plexus. The results were compared with surgical findings, intraoperative neurophysiology, and subsequent clinical progress. Operations for exploration and repair have been performed in 23 and 26 patients scanned. Evidence of root avulsion was seen in 11 patients in the form of displacement or oedema of the spinal cord, haemorrhage or scarring within the spinal canal, absence of roots in the intervertebral foramena, and meningoceles. Characteristic abnormalities were evident in the MR scans of all cases where exploration confirmed some root avulsions. There were no false positives. MRI underestimated the number of individual roots avulsed; sensitivity was 81%. Post-ganglionic lesions were seen as swelling on T1 images associated with increasing signal on T2 images. It was usually possible to define the level of the injury within the plexus. This study suggests that MR imaging, performed early after traction injury to the brachial plexus, provides useful additional information towards establishing the level of the lesion. It also provides information about injury to the plexus outside the spinal canal.     

Local staging with magnetic resonance imaging after neoadjuvant hormonal therapy for prostate cancer]

We retrospectively studied the staging accuracy of magnetic resonance (MR) imaging after neoadjuvant hormonal therapy (NAH) for 21 localized prostate cancers. MR imaging was performed using a 1.5-Tesla magnetic resonance system with a pelvic phased array coil. T2-weighted MR images were obtained on axial and coronal planes, and T1-weighted MR images using the dynamic technique with Gd-DTPA bolus enhancement were obtained in axial planes for each patient. On T2-weighted imaging, the signal intensity of the normal tissue in the peripheral zone became lower after NAH. Therefore, it was more difficult to detect residual malignant lesions in many cases than before NAH. The accuracy of T staging for prostate cancer after NAH in MRI was 71%. The accuracy, sensitivity, and specificity of the extracapsular invasion was 76%, 0% and 94%, respectively, and those of the seminal vesicular invasion 85%, 0% and 100%, respectively. While 2 of the 4 patients judged as downstaged cases in MRI showed corresponding pathological findings, 5 of the 21 cases (23.8%) were underdiagnosed. Local staging with only MRI for prostate cancer after NAH seems to have limits in applicability.     

Correlation of clinical, surgical, pathologic, and MR fat suppression results for head and neck cancer.

Magnetic resonance (MR) imaging provides superior soft tissue delineation of head and neck tumors compared to previous radiologic studies. Further refinements using fat suppression and gadolinium (Gd-DTPA) enhancement have added to these improved images. We performed MR studies of 16 patients with head and neck tumors with detailed clinical, surgical, and pathologic information. MR studies included standard spin-echo T1-weighted images (T1WI) with and without fat suppression and T2-weighted images (T2WI) with fat suppression. Gadolinium was also administered with fat suppression. Conventional and paired fat suppression MR images were compared by a grading system. Post-Gd-DTPA fat suppression T1WI, and T2WI with fat suppression, showed superior sensitivity for tumor delineation when compared to conventional T1WI. Fat suppression T2WI was the best technique to delineate squamous cell carcinoma both in the primary site and regional lymph nodes. Clinical, surgical, and pathologic results correlated perfectly with imaging findings. These refinements in MR imaging represent a significant advance in the radiologic evaluation of head and neck tumors.     

自发性脊柱硬膜外血肿的非典型MRI表现与鉴别诊断

目的 提高对自发性脊柱硬膜外血肿非典型MRI表现的认识.方法 对2000年至2008年来院的10例自发性脊柱硬膜外血肿非典型MRI表现进行分析,男7例,女3例;年龄12--64岁,平均32.1岁.所有病例均无明显的外伤史.常规行矢状位T1WI、T2WI,横轴位TwI,8例行增强扫描.结果 血肿呈梭形、椭圆形,位于脊髓的侧后方或后方的硬膜外腔.血肿发生于颈段5例,胸段3例,胸腰段2例.病灶与脊髓之间有一低信号线状影相隔,尤以T2WI显示最佳.血肿范围多在2～4个椎体,总量约5～10 ml,均值为(6.9±1.8)ml.在T1WI图像上,6例表现为等信号,4例表现为高信号;在T2WI图像上,6例表现为混杂高信号,4例表现为混杂低信号.5例血肿壁边缘轻度强化.6例血肿MRI信号比较典型.4例血肿MRI信号不典型.活动性出血以及血肿因时间而演变是血肿征象不典型的原因.本组4例误诊的原因:(1)活动性出血所致血肿征象不典型;(2)血肿位于狭窄的腔隙内;(3)临床上无外伤史.结论 根据血肿演变的规律,结合起病时间及可能存在活动性出血对血肿MRI信号进行分析,有利于对非典型血肿的诊断和鉴别诊断.     

Current role of CT and whole body MRI in multiple myeloma

Radiology of bone lacunae can help differentiate between smouldering and symptomatic myeloma. CT seems to be more apt for this purpose than a standard X-ray but appropriate principles must be applied when performing and reading it. Lesions visible in an MRI above all allow myelomas to be monitored during treatment. Because of the radiation dose, whole body CT must be performed with a slice thickness of 2 mm, increments of 1.5 and intensity of 40 mAs. It should be read associating the reading of the axial slices with reading the mean coronal and sagittal projections of a thickness of 2 cm. Whole body MRI must associate T1-weighted sagittal, STIR coronal and b-800 diffusion-weighted axial sequences. Changes in the disease correlate with changes in the diffusion, STIR and T1-weighted images interpreted together. While whole body CT has a place in clinical routine, the indication for whole body MRI still needs to be clarified and has yet to take its place in research protocols.