全膝关节置换术中股骨假体旋转对线的比较研究

目的 比较全膝关节置换术(TKA)中以经上髁轴和股骨后髁轴外旋3°置放股骨假体外侧支持带的松解率.方法 150例膝关节骨性关节炎患者随机分成两组,一组采用股骨上髁轴确定股骨假体的旋转对线(股骨上髁组),另一组参照股骨后髁连线外旋3°确定股骨假体旋转对线(股骨向髁组).假体安装完毕后以"无拇指"技术评价髌骨轨迹,决定是否需要做外侧支持带松解.结果 股骨上髁轴组外侧支持带松解率为6.3%,股骨后髁轴组外侧支持带松解率为15.8%(P＜0.05). 结论 TKA中股骨假体旋转对线对于髌股轨迹的优劣有着显著影响,股骨上髁轴作为旋转对线的参照可以显著改善髌股轨迹,降低外侧支持带松解率.     

股骨后髁角与股骨假体旋转对线在人工全膝关节置换术中的应用

全膝关节置换术(total knee arthroplasty,TKA)中,股骨假体对线决定了髌骨轨迹及膝关节屈膝间隙的稳定性[3].若股骨假体安放不当会导致髌骨与股骨假体的过度磨损,从而使假体寿命缩短或出现一系列髌骨并发症及膝前痛等症状.股骨外科上髁轴(surgical epicondylar axis,SEA)是膝关节屈伸旋转轴线.传统的根据股骨后髁轴(posterior condylar line,PCL)外旋3°截骨安放股骨假体的方案缺乏个性化,有学者建议在TKA之前行CT检查测量股骨后髁角(posterior condylar angle,PCA),从而使TKA术中股骨假体的旋转对线尽量与SEA平行,从而达到最好的力学重建效果[3].笔者通过测量TKA术后患者股骨假体PCA及髌骨适合角(congruence angle,CA)和外侧髌股角(lateral patellofemoral angle,LPTA),旨在分析术后假体PCA与CA及LPTA间的相关关系,以及不同手术方式对患者术后CA及LPTA的影响.     

股骨滑车轴作为全膝置换股骨旋转截骨轴线的可靠性评估

目的 研究股骨滑车轴( trochleare line,TL)作为全膝置换股骨假体旋转对位标志的可靠性. 方法 对89例正常成人膝关节CT扫描,在横断面图像上定位外科经股骨上髁轴(surgical transepicondylar axis,STEA)、股骨后髁轴(posterior condylar line,PCL)和TL.测量TL相对于STEA旋转的角度(TSA)、TL相对于PCL旋转的角度(TPA)、PCL相对于STEA旋转的角度(PCA),比较它们相对STEA的可靠性. 结果 TSA为(6.77±3.12)°、TPA为(4.22±2.64)°、PCA为(2.95±1.77)°,三种角度2×2析因分析性别、左右差异均无统计学意义(P＞0.05),秩和检验( HC=66.837,P＜0.01)结果 提示三组角度总体分布不同.TSA的变异系数较小,但标准差较大(3.12°).结论 TL仅可作为股骨假体旋转对位的辅助性标志.     

维吾尔族正常膝关节参数的测量结果及其意义

目的：应用CT测量维吾尔族正常膝关节参数并探讨其临床价值及膝关节假体设计的指导作用。方法根据纳入标准招募维吾尔族志愿者120名,男性62名,女性58名;年龄18～70岁,平均（35.1±2.7）岁。行膝关节伸直中立位CT扫描,扫描图像行三维重建处理后,随机选取左侧或右侧膝关节,分别测量记录髌骨厚度,胫骨平台内翻角（ PT角）,小腿机械轴垂直线与双侧股骨髁远端切线的夹角（ FT角）和胫骨内侧平台最低点至腓骨头尖端高度的差距（ DPF）等膝关节参数。将所得数据分别按男女组进行统计学处理,并将所得数值同汉族相关研究所得数据进行统计学比较。结果维吾尔族正常膝关节髌骨厚度、PT角、FT角、DPF,男性与女性之间的差异均有统计学意义。与汉族相比髌骨厚度、PT角、FT角之间的差异无统计学意义,DPF之间的差异有统计学意义。结论对维吾尔族患者行全膝关节置换术、髌骨置换术等操作时,不能直接参考其他人群相关数据;为确保操作的精确性,设计国人膝关节假体时应考虑到性别及不同族别人群间的差异。     

膝关节低场MRI最佳检查方法的回顾分析

目的:探讨膝关节低场磁共振的最佳检查方法。方法:在76例77个膝关节MRI检查中,冠状面图像的第一定位线是在横断面图像上内、外侧髁后缘连线的平行线;第二定位线是在矢状面图像上以胫骨髁间隆起的上缘为中心做股骨-胫骨长轴的平行线。矢状面图像的第一定位线是在冠状面图像上内、外侧半月板中心连线的垂线向外上内下倾斜,第二定位线是在横断面上内、外侧髁后缘连线的垂线向内前外后倾斜。结果:冠状面显示半月板、侧副韧带最佳,矢状面显示半月板、交叉韧带最佳,矢状面第一定位线平均倾斜角度(-x±s)为6.9°±1.3°,第二定位线倾斜角度平均为5.8°±1.4°。结论:在做膝关节MRI检查时,矢状面扫描双定位线的角度和方向要做适当调整,以便清晰显示前交叉韧带。     

渐变形面膝关节假体设计及接触应力分析

目的研究膝关节假体形面轮廓对假体关节面间接触应力的影响。方法基于MRI(magnetic resonance imaging)图像采集建立多角度正常膝关节模型。依据自然膝关节的解剖结构,从中提取出个体膝的结构尺寸及形面特征,设计出渐变形面的膝关节假体,按照全膝关节置换手术的规范流程建立植入渐变形面假体后的全膝三维模型,并通过有限元分析,比较植入假体后对股骨/胫骨关节面等效应力的影响。结果植入渐变形面的假体膝在屈曲角度0°~60°时对于髁面的应力分布影响不大,但大于60°,尤其是80°时,应力分布变化明显;另外,对内/外侧髁面的最大等效应力有较大的改变。结论在膝关节假体的设计建模中,尽量重现人体关节构造,益于保证置换后整个膝关节的协调运作。整个设计过程及方法对于完善和改进假体的设计具有重要的参考意义。     

螺旋CT在儿童漏斗胸中的应用

目的探讨Haller指数和心脏旋转角对漏斗胸的应用价值。方法对我院2004-03—2005-07间经手术治疗的35例患漏斗胸的患儿胸部CT检查进行回顾性的分析。Haller指数的计算方法为胸部最大内横径与同层面最小前后深度的比值。心脏旋转角的测量方法为:胸椎椎体前缘至心尖连线及其与胸矢状线的夹角。在CT图像上测定漏斗胸患者于手术前、手术后及正常对照组之间的Haller指数及心脏旋转角,并对测量数据进行统计学分析。结果35例漏斗胸患者均显示有不同程度的胸骨凹陷。手术前测量的Haller指数为5.4±1.8,手术后为3.1±1.6,两者间差异有非常显著性意义(t=7.34,P<0.01)。手术前心脏旋转角为67.8°±10.8°,手术后为62.1°±9.3°,两者间有显著性差异(t=2.42,P<0.05)。正常对照组的Haller指数为2.4±0.3,心脏旋转角为49.4°±2.5°。Haller指数增加,心脏旋转角也增大,两者间呈正相关,其相关系数为0.82(P<0.01)。4例术前CT检查提示有肺部病变,7例术后CT检查显示有肺实变。结论Haller指数和心脏旋转角是评价儿童漏斗胸的2个重要指标。     

前交叉韧带股骨止点的放射学研究

目的:通过分析前交叉韧带(ACL)股骨止点的X线影像学位置与特点,为ACL双束重建时股骨骨道定位及术后评估提供依据。方法:30例成人膝关节标本,屈膝60°,根据纤维张力的不同将ACL分成前内束(anteromedial band,AMB)和后外束(posterolateral band,PLB),将两束自股骨止点切除,用金属丝标记ACL股骨止点边缘及两束交界线,用金属钉标记两束股骨止点中心点;同时标记模拟ACL重建术AMB股骨骨道的中心点。测量膝关节髁间窝位X线片及侧位片中的上述标记位置。结果:在髁间窝位X线平片上:AMB股骨止点范围是9∶55±16.52′~11∶20±4.50′(右膝),0∶42±6.12′~2∶08±14.50′(左膝),其中心点位于10∶18±12′(右膝),1∶40±10′(左膝);PLB股骨止点的范围是8∶55±7.17′~10∶23±21.17′(右膝),1∶38±17.5′~2∶08±5.70′(左膝),其中心点位于9∶30±16.32′(右膝),2∶32±14.12′(左膝);模拟ACL重建中AMB股骨骨道中心点位置是10∶55±5′(右膝),1∶03±8′(左膝);AMB、PLB股骨止点分界线的位置在9∶55±16.52′~10∶23±21.17′(右膝),1∶38±17.15′~2∶08±14.50′(左膝)。在侧位X线平片上:AMB股骨止点范围在股骨外髁长度的7.23±4.09%~38.66±8.06%,股骨外髁高度的3.99±4.48%~41.38±10.44%,其中心点位于股骨外髁长度的22.0±4.43%、高度的27.1±8.08%;PLB股骨止点范围在股骨外髁长度的13.05±6.37%~46.22±12.88%,股骨外髁高度的38.32±22.37%~65.41±14.25%,其中心点位于股骨外髁长度的32.7±6.20%、高度的51.2±9.65%;模拟ACL重建中AMB股骨骨道中心点位置为股骨外髁长度的16.0±6.57%、高度的14.97±6.36%。结论:AMB股骨等长重建点与AMB止点解剖中心点不重合。ACL股骨止点X线影像学研究可以为ACL双束重建术中的股骨骨道定位及术后骨道位置评估提供实验依据。     

人工关节置换治疗晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形

目的 探讨晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形患者采用普通假体髋关节置换的手术方法及临床疗效.方法 本组男9例,女6例;年龄30～42岁,平均37岁.前倾角40°～50°,术前Harris评分(59±8)分,术中通过将股骨假体缩小前倾角20°～30°,同时将髋臼杯前倾角增大10°～15°,使其基本恢复正常对合关系,防止关节前脱位.术后定期影像学检查和临床疗效Harris髋评分.结果 术后15例患者均获得随访2.5～3.7年(平均2.9年),关节假体稳定性良好,关节活动度基本正常.术后2年Harris评分为(88±6)分,与术前相比,疗效显著(P<0.01).结论 晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形患者手术中通过对普通的股骨假体及髋臼杯安放的角度的联合调整,使关节置换术后人工假体与髋臼的对合基本恢复正常,疗效显著,同时避免了使用小柄股骨假体、转子下截骨或使用特殊前倾角股骨假体等治疗方法.     

显露增强技术与股骨髁推顶技术在膝关节镜内侧半月板后角修复中应用

目的探讨应用显露增强技术与股骨髁推顶技术治疗膝关节半月板后角的临床疗效。方法选取北部战区空军医院自2016年1月至2019年6月收治的52例内侧半月板损伤患者为研究对象。应用半月板缝合系统,采用显露增强技术与股骨髁推顶技术修复内侧半月板后角水平撕裂,术后采用Lysholm评分系统进行疗效评价。结果患膝术后平均活动度为(131.5°±17.3°),显著大于术前的(114.2°±10.7°),差异有统计学意义(P<0.05);患者术后Lysholm评分为(85.3±7.1)分,显著高于术前的(65.9±9.3)分,差异有统计学意义(P<0.05)。所有患者均未出现关节内或浅表感染、下肢深静脉血栓等并发症。结论显露增强技术与股骨髁推顶技术修复内侧半月板后角疗效满意,有利于改善膝关节疼痛、活动度,增强残余半月板的稳定性。     

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young healthy volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

MR angiography of congenital heart disease: Value of segmented two-dimensional inflow technique and maximum-intensity-projection display

Magnetic resonance (MR) angiography of the cardiovascular system was evaluated in 41 patients with congenital heart disease by using a two-dimensional (2D) inflow technique based on a magnetization-prepared gradient-echo pulse sequence with segmented k-space data acquisition and electrocardiographic gating at 0.5 T. Inversion and saturation prepulses were used to suppress stationary tissue and enhance intravascular signal. Presaturation slabs were applied where certain vascular structures had to be suppressed. Sequence parameters were optimized by evaluating signal intensity and contrast characteristics for various flip angles and inversion and saturation delay times. The heart and intrathoracic vasculature were encompassed with 40–50 overlapping sections. Both 2D angiograms and maximum-intensity-projection images were evaluated. Combining data sets acquired in the sagittal and transverse orientations provided the most satisfactory information about the pulmonary arteries. The highest signal-to-noise ratios were obtained with a flip angle of 65° and short prepulse delay times. Two-dimensional MR angiography can provide useful diagnostic information but requires a thorough understanding of in-plane and hemodynamically induced signal intensity changes.     

MR imaging of disorders of the brachial plexus

The authors evaluated 64 consecutive patients with suspected brachial plexus (BP) abnormalities of diverse cause with magnetic resonance (MR) imaging, using the body coil and a standardized protocol. Of the 43 patients for whom follow-up was available, 25 were suspected of having neoplastic involvement of the BP, nine had sustained injuries, and nine presented with BP symptoms of uncertain cause. MR imaging was 63% sensitive, 100% specific, and 77% accurate in demonstrating the abnormality in this diverse patient population. When patients with neoplastic and traumatic disorders were considered separately, sensitivity increased to 81%, accuracy to 88%, and specificity remained unchanged. In the patients with a clinical diagnosis of idiopathic or viral plexitis, the MR imaging findings were normal, serving to exclude other structural abnormalities. It is concluded that MR imaging is valuable in the assessment of a wide range of BP disorders.     

MR imaging characteristics of noncancerous lesions of the prostate.

Radical prostatectomy specimens from 53 men with clinical stage A or B prostate cancer were retrospectively reviewed and compared with correlative axial T2-weighted magnetic resonance (MR) images obtained just before surgery. Non-cancerous lesions were evaluated for signal intensity and location. Focal high-signal-intensity areas (n = 72) were present in 81% of patients. The 26% of lesions seen in the central gland all correlated with cystic atrophy. Of the 53 lesions seen in the peripheral prostate, 47 (89%) were cystic atrophy without associated cancer, four (7.5%) cystic atrophy with cancer, and two (3.8%) focal inflammation. Focal low-signal-intensity areas (n = 42) were present in 60% of patients. Of the 31% of lesions in the central prostate, one-fifth correlated with benign prostatic hyperplasia (BPH) and four-fifths with fibrous tissue. Of the 69% of peripheral lesions, 83% corresponded to fibrous tissue, 10% to BPH, and 7% to normal tissue. Mixed lesions (n = 42) were present in 64% of patients; 86% of these were located centrally and 14% peripherally. All mixed central lesions were BPH; the peripheral lesions were areas of combined cystic atrophy and fibrosis. BPH of low or mixed signal intensity can extend into the peripheral prostate and mimic cancer. High-intensity cystic atrophy associated with cancer can mimic normal tissue.     

肾细胞癌的MRI研究进展

肾细胞癌是最常见的成人肾脏恶性肿瘤。近年来，多种功能MRI成像技术（如扩散加权成像、灌注加权成像等）、多参数MRI联合分析以及影像组学等新兴影像处理技术被证实在肾细胞癌的诊断中具有较大的价值。目前，研究热点多集中于良恶性肿瘤的鉴别、组织学亚型的区分、肿瘤分期、预测核分级及判断预后。就MRI新技术及图像处理技术在肾细胞癌中的研究进展予以综述。     

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise.     

Influence of in vivo copper on MR images of the liver in rats

To investigate the effects of in vivo copper on magnetic resonance (MR) images, the authors studied Long-Evans cinnamon rats, which develop hepatitis and hepatocellular carcinoma as a result of abnormal copper metabolism. The livers of the rats were imaged before hepatitis developed; the absence of hepatic disease was confirmed histopathologically. The copper that accumulated in the liver of the rats was thought to exist in the form of divalent ions, which were suspected of reducing the T1 and T2 of neighboring protons. However, the signal intensities of the liver on T1- and T2*-weighted images did not change, suggesting that in vivo copper, even when accumulated abnormally, does not influence the signal intensity of MR images.     

Techniques for high-resolution MR imaging of atherosclerotic plaque

Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.     

Dynamic MRI of the gallbladder lesions: Differentiation of benign from malignant

Forty-nine pathologically proven gallbladder lesions were evaluated in 45 patients using dynamic MRI with a spoiled gradient pulse sequence (SPGR), to access the ability of this technique to differentiate benign from malignant gallbladder lesions. The studies were reviewed retrospectively. Signal intensity of the lesions were measured. Twenty-one malignant and 28 benign lesions were classified into three categories: polypoid, diffuse wall thickening, and exophytic. Early and delayed enhancement patterns were evaluated. For the polypoid masses, malignant lesions (n = 9) demonstrated early and prolonged enhancements, whereas benign lesions (n = 14) had early enhancement with subsequent washout (P < .05). For diffuse gallbladder wall thickening, malignant lesions (n = 6) demonstrated early and prolonged enhancement and benign lesions (n = 14) showed relatively slow, prolonged enhancement (P < .05). The exophytic masses (n = 6) all were malignant and demonstrated early and prolonged enhancement. Dynamic MRI can help differentiate benign from malignant gallbladder lesions.