多层螺旋CT面神经管曲面重建与解剖对照研究

目的探讨螺旋CT面神经管曲面重建(curved p lanar reform ation,CPR)的方法并研究其解剖学的可靠性。方法20具(40侧颞骨)成人尸头标本行高分辨CT扫描及面神经管轴位、冠状位和矢状位曲面重建并测量各段长度、直径和2个弯曲的角度,观察重建图像上面神经管各段的形态及走行;对40侧颞骨标本的面神经管进行解剖,测量相应各段长度、直径和2个弯曲角度,并观察面神经管形态及走行。结果①3个方向CPR图均能将面神经管全程直观地显示在1幅图像上,可清楚的显示面神经管在颞骨内的走行、形态和管壁等情况;②重建图像均可准确测得各段长度、直径及锥曲角度,冠状位和矢状位能准确测量膝状神经节角度,与解剖测量结果一致(P>0.05);③迷路段和膝状神经节的形态与走行方向在冠状位CPR显示好,水平段、锥曲及垂直段形态和走行在轴位CPR显示好,与解剖具有很好的对应性。结论面神经管高分辨率CT图像的CPR为研究面神经管影像解剖良好的、可靠的方法,可代替解剖测量与观察。     

大前庭导水管综合征的高分辨率CT及MRI表现

目的 探讨大前庭导水管综合征的高分辨率CT(HRCT)及MRI表现.方法 回顾性分析21例大前庭导水管综合征患者的影像资料,包括HRCT多平面重组(MPR)、曲面重组(CPR)图像及MRI,观察病变侧内、中耳各解剖结构的形态,测量病变前庭导水管的径线,总结分析本病的影像学特征.结果 21例患者中,双侧患病18例,单侧3例,18例为单纯前庭导水管扩大,2例合并双侧耳蜗发育不良,1例合并单侧听骨链畸形.结论 综合应用HRCT的MPR、CPR图像及MRI,可更全面诊断大前庭导水管综合征及其伴发畸形.     

胆脂瘤型中耳炎对面神经管破坏的高分辨率CT评价

目的 探讨HRCT及图像后处理技术对胆脂瘤型中耳炎继发面神经管破坏的诊断价值.方法 对80例胆脂瘤型中耳炎患者进行颞骨轴位HRCT扫描,利用多平面重建(MPR)、双斜位MPR及曲面重建(CPR)技术进行面神经管重建.结果 71例患者为单侧胆脂瘤,9例为双侧胆脂瘤(共89耳).64耳发现面神经管骨质破坏,表现面神经管壁骨质模糊、缺损,以鼓室段最多见,占73.44%(47/64),Austin Ⅲ～Ⅳ度胆脂瘤累及面神经管的比例占87.5%(56/64),其中13耳为多节段破坏.手术发现39耳面神经管骨质缺损,破坏范围>5 mm占82.05%(32/39).结论 HRCT扫描及图像后处理技术能准确诊断中耳胆脂瘤继发的面神经管破坏,对临床手术有重要指导意义.     

面神经管的多层螺旋CT曲面重建

目的　研究应用多层螺旋CT在同一幅图像上显示双侧面神经管全貌的方法。方法用多层螺旋CT对 6 0个病人的颞骨行高分辨率CT轴面扫描。扫描参数 :12 0kV ,2 0 0～ 2 5 0mAs ,准直0 .5mm ,螺距 0 .875 ,扫描时间 0 .75s/周 ,矩阵 5 12× 5 12。重建间隔 0 .1～ 0 .2mm ,重建矩阵 10 2 4×10 2 4。用PhilipsMx80 0 0工作站 ,分别在轴面及多平面重建 (MPR)的冠状面、矢状面图像上行面神经管的曲面重建 (CPR)。轴面上的面神经管重建时 ,使用曲面重建功能绘制 1条沿一侧面神经管走行的CPR参考线 ;自内耳道起始部开始 ,沿着面神经管的走行 ,参照矢状面和冠状面面神经管的位置 ,在各层面上不断校正CPR参考线 ,使之位于面神经管的中央 ,直至茎乳孔 ,即可获得一侧面神经管全貌的曲面重建图 ;并将CPR参考线自内耳道起始端延伸至对侧 ,依上述步骤校正此线 ,即可在同一幅图像上获得双侧面神经管的全貌。在MPR的冠状面及矢状面上行单侧或双侧面神经管的CPR ,方法与轴面上的CPR相似。结果　 6 0例中的 5 6例轴面及MPR冠状面上CPR图像能清晰显示单侧或双侧面神经管的全貌 ;MPR的矢状面上同时行双侧面神经管的曲面重建 ,结果不满意 ,往往一侧显示清晰 ,另一侧只能显示部分面神经管 ,因此 ,只能左右侧分别重建显示。 4例面     

颞骨-中内耳解剖变异畸形高分辨CT表现及临床意义

目的探讨先天性颞骨-中内耳解剖变异畸形的高分辨CT(HRCT)特征表现,为耳科诊治疾病提供有价值的参考依据。方法收集41例(76耳)病例采用HRCT横断面扫描+冠状位扫描,分析先天性颞骨-中内耳解剖变异畸形的HRCT表现。结果颈静脉高位20例(23耳)、鼓室盖不连续13例(15耳)、乙状窦前位8例(13耳)、岩鳞隔过长8例、中颅窝低位5例、颈静脉裸露5例、乳突窦未发育1例、Michel畸形1例、Mondini畸形3例(6耳)。结论 HRCT可清晰显示颞骨-中内耳解剖变异畸形的表现,能明确颞骨-中内耳解剖变异畸形的诊断并对临床诊疗及手术路径具有指导意义。     

外伤性面瘫的多层螺旋CT研究

目的探讨多层螺旋CT(MSCT)在外伤性面瘫中的应用价值。方法用MSCT对41例外伤性面瘫的颞骨行高分辨率轴面扫描。用Ph ilipsMx8000MSCT工作站,行岩锥感兴趣区的多平面重建(MPR)及面神经管的曲面重建(CPR)。观察骨折类型,骨折线的走行,中耳腔、乳突积血及外耳、中耳、内耳和面神经管的受累情况。结果41例患者中,39例颞骨有不同部位、不同类型的骨折,其中岩骨纵行骨折34例,横行骨折2例,混合型2例,1例岩骨无骨折,但颞骨鳞部骨折,2例未发现骨折。其中2例为双侧岩骨骨折。面神经管的CPR及MPR显示21例患者面神经管受累,9例可见骨碎片。结论MSCT扫描及重建技术能清晰显示面神经管的全貌及其损伤,对外伤性面瘫的诊断有重要意义。     

后鼓索神经小管的CT多向调整多平面重组及曲面重组

目的 探讨多向调整多平面重组(MPR)及曲面重组(CPR)全程显示后鼔索神经小管的方法.方法 对76例(106耳)正常颞骨行高分辨率CT 各向同性扫描,再做多向调整MPR及CPR,以显示后鼔索神经小管并进行测量.结果 MPR及CPR的后鼔索神经小管显示率均为96.2%,但以后者图像为佳.有4耳经反复多次MPR及CPR均未能观察到后鼔索神经小管.1耳可见2支后鼔索神经小管在不同平面自乳突段分出,后又合并成单一的后鼔索神经小管.在轴面像上,后鼔索神经小管汇入处位于面神经管前外侧、外侧、后外侧及前方的分别为48.1%、45.1%、3.9%及2.9%.汇入处距茎乳孔距离为(2.93±2.72)mm.后鼔索神经小管与面神经管的夹角为36.10°±15.44°.显示后鼔索神经小管的MPR重组基线的轴位及冠状位旋转角度,右耳分别为顺时针18.66°±7.86°及逆时针10.60°±6.15°,左耳分别为逆时针17.75°±6.47°及顺时针11.54°±6.41°.后鼔索神经小管长度及内径分别为(9.34±2.51)mm及(0.41±0.07)mm.结论 多向调整MPR及CPR可全程显示后鼔索神经小管,是研究后鼔索神经小管解剖的重要方法.     

多层螺旋CT曲面重建在先天性外耳道闭锁中面神经管异常的研究

目的用多层螺旋CT(MSCT)曲面重建(CPR)技术研究先天性外耳道闭锁中面神经管的异常。方法对15例(17耳)先天性外耳道闭锁患者进行多层螺旋高分辨率CT(HRCT)扫描,图像后处理在Philips Mx8000工作站进行。结果17耳中,外耳道狭窄2耳,外耳道膜性闭锁2耳,骨性闭锁13耳。外耳道先天性胆脂瘤及耳后瘘管1耳。鼓室畸形3耳。听小骨先天畸形7耳。内耳畸形1耳。面神经管异常17耳。其中面神经管总长度变短11耳,面神经管走行异常5耳,面神经管位置异常9耳,面神经管管径变细1耳,面神经管分叉1耳。结论MSCT高分辨率扫描加CPR技术能清晰显示先天性外耳道闭锁患者中面神经管的异常,有利于临床医生术前详尽了解面神经管的行程,减少不必要的面神经意外损伤。     

64排CT三维透明化重组在内耳畸形诊断中的应用

目的探讨三维透明化重组在内耳畸形诊断中的应用价值,为先天性内耳疾病提供准确的影像诊断和临床治疗信息。资料与方法回顾32耳内耳畸形的64排高分辨率CT(HRCT)容积数据,行三维透明化重组处理,按内耳畸形分类总结三维透明化重组方法及影像表现。结果 32耳的三维透明化容积再现(VR)图像结合透明化多平面重组(MPR)图像均能很好揭示内耳畸形病变部位及程度,内耳病变整体显示方面及蜗窗、前庭窗、半规管等细节病变显示中透明化VR像及透明化MPR像明显优于轴位像及普通MPR像;在耳蜗内部结构的显示中,透明化MPR、轴位像及普通MPR像优于透明化VR像。32耳先天内耳发育畸形有以下几种:耳蜗未发育(2耳);共同腔畸形(4耳);不完全分隔Ⅰ型(2耳,2例患者对侧耳均为共同腔畸形);不完全分隔Ⅱ型(即Mondini型)(16耳,多合并前庭、半规管及前庭导水管畸形);单纯前庭-半规管畸形(2耳);单纯前庭导水管扩大(6耳)。结论三维透明化个性重组能准确评价内耳先天性疾病的类型和程度,为临床治疗提供重要的参考依据。     

MSCT的MPR矢状位重建对慢性化脓性中耳炎的临床应用价值

目的探讨MSCT的MPR矢状位重建对慢性化脓性中耳炎的临床手术应用价值。方法对61例76耳慢性化脓性中耳炎行MSCT检查,在轴位HRCT及矢状位MPR图像上观察中耳结构及病变显示情况并与手术结果进行对照。结果矢状面MPR图像可良好显示颞骨结构及其周围结构的毗邻关系,对面神经鼓室段及垂直段、乙状窦板及颈静脉球等结构显示尤佳。在MPR矢状位重建图像上38耳中耳炎可见中耳骨壁及听骨链的“人”字形结构有不同程度的破坏。16耳(肉芽肿型5耳,胆脂瘤型11耳)面神经管破坏鼓室段12耳,乳突段4耳,其中3耳胆脂瘤型的面神经管鼓室段和乳突段均有骨质破坏;骨性半规管受累伴骨质破坏12耳;解剖变异有乙状窦前置8耳,乙状窦的前壁至外耳道后壁的最短距离约0.4～0.8cm,平均0.6cm;2例高位颈静脉球;均得到手术证实。结论矢状位MPR图像对慢性中耳炎累及面神经骨管损伤程度、位置及与周围位置的毗邻关系的显示具有重要的临床应用价值。     

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.