正常成人内耳系统液体容积的磁共振测量与分析

目的 探讨磁共振三维水成像技术在内耳液体容积测量中的应用价值.方法 30例正常成人志愿者均采用GE1.5T磁共振机、8通道头部相控阵线圈,行内耳内听道水成像序列扫描(三维真稳态进动快速成像序列),所采集信号传送至工作站AW4.2进行多平面重建和容积重建,测量耳蜗、前庭-半规管和内听道容积,初步建立其正常值范围,并分别比较耳别、性别及年龄段间有无差异.结果 30例(60耳)正常志愿者的耳蜗、前庭-半规管和内听道容积分别为(101.2±11.1)mm3、(151.5±19.9)mm3和(220.1±58.7) mm3;正常值范围分别为(79.4～123.0)mm3、(112.5～190.5)mm3和(105.0～335.2)mm3;变异系数分别为0.11、0.13和0.27.内耳系统液体容积在耳别、性别及年龄段间差异均无统计学意义(P＞0.05).结论磁共振三维水成像技术可用于活体内耳系统液体容积的测量,为临床上内耳腔道结构的评估及内耳畸形的分类、分型提供影像解剖学依据.     

MR内耳水成像技术在人工耳蜗植入术中的应用价值

目的 探讨MR内耳水成像技术在人工耳蜗植入术中的应用价值。方法 回顾性分析2015年4月—2016年3月在黑龙江省医院和哈尔滨医科大学附属第四医院行人工耳蜗植入术的128例患者的影像资料,其中男68例、女60例,年龄4～48岁,右耳植入101例、左耳植入27例。患者术前、术后均行头颅内听道螺旋CT及MR内耳水成像检查,并比较两种检测方法对患者内耳、中耳畸形及病变的检出率。结果 MR内耳水成像内听道总体异常检出率90.63%(116/128),CT检出率为76.56%(98/128),二者比较差异有统计学意义(χ²=9.228,P＜0.05)。在前庭导水管异常、耳蜗畸形、内听道狭窄、耳蜗纤维化等疾病,MR诊断的灵敏度、特异度、准确度、阳性预测值和阴性预测值均高于CT,但差异均无统计学意义(P值均>0.05)。结论 在人工耳蜗植入术前、术后进行MR内耳水成像技术检查,可有效了解患者内听道解剖学信息,对治疗方案的选择具有指导性意义,值得临床进一步推广应用。     

CT与磁共振图像融合技术对显示正常内耳结构的应用价值

目的 探讨内耳CT与磁共振成像(MRI)图像融合的可行性以及融合图像对正常内耳结构的显示能力.方法 对20例(40耳)双侧内耳及内听道形态正常的感音神经性耳聋患者行多层螺旋CT(MSCT)和MRI扫描,并应用西门子图像融合软件将CT与MRI图像进行配准、融合,然后半定量评价融合图像对正常内耳和内听道结构的显示能力.结果 CT与MRI融合可有9种融合模式,在不同融合模式的图像中CT不反相+MRI反相对骨迷路显示最清晰;CT反相+MRI不反相、CT反相+MRI伪彩对膜迷路显示最清晰、立体感强;CT不反相+MRI反相、CT与MRI均反相对面神经、听神经及蜗神经显示最清晰、最直观、立体感最强;CT不反相+MRI反相、CT反相+MRI不反相、CT伪彩+MRI反相对蜗孔处蜗神经显示最好.结论 CT与MRI图像可以进行精确配准和融合,不同模式融合图像对内耳不同结构的显示清晰度不同.     

蜗神经发育不良患者的影像及听力学表现分析

目的 探讨蜗神经发育不良（CND）患者的影像学表现和听力学表现以及两者的相关性。方法 对北京大学第三医院耳鼻咽喉科拟行单侧人工耳蜗植入,合并蜗神经发育异常的患者共7例（12耳）进行回顾性分析,对患者进行听力学检查,以及颞骨高分辨率CT及内耳道MRI等影像学检查,并在颞骨CT中测量内耳道（IAC）及蜗神经管（BCNC）直径,在内耳道MRI中测量内耳道内神经束数目、蜗神经有无狭窄或缺失等指标,并观察有无内耳畸形。分析不同影像学表现下听力情况的差异。结果 7例患者影像学表现均提示蜗神经发育不良。颞骨CT中,3例（5耳）提示内耳道异常,6例（9耳）提示蜗神经管狭窄或缺失,内耳道MRI所见中;7例（12耳）提示蜗神经狭窄或缺失,其内耳道内神经束数目在0～3根不等。此外,影像学检查发现,4例（8耳）合并不同类型的内耳畸形。7例患者听力学表现均为双耳重度或极重度感音神经性听力下降。CND的不同影像学表现（包括IAC、BCNC、内耳道神经束数目、有无内耳畸形等）下,各组间平均听阈差异不显著（P>0.05）。结论 蜗神经发育异常的影像学特点包括颞骨CT中内耳道及蜗神经管的异常,内耳道MRI中神经束数目及蜗神经的异常等,听力多表现为重度或极重度感音神经性聋,影像学及听力学表现之间未发现明显关联。对该类患者的人工耳蜗植入存在较大的挑战。     

15例成年国人内耳膜迷路及内耳道MRI最大密度投影三维重建图像的解剖学研究

目的研究成年国人内耳膜迷路及内耳道最大密度投影(MIP)三维重建图像,观测内耳主要结构磁共振成像(MRI)的正常解剖测量值,为临床耳显微外科及神经外科手术提供解剖学依据。方法选用15名健康志愿者,使用GE-signal 1．5T超导型核磁共振机,环行耳颞部线圈,三维快速自旋回波序列(3D／FSE／T2W1)(水成像)及脂肪抑制技术,对两侧耳部同时进行扫描。原始扫描图像行MIP三维重建,多角度旋转对内耳主要结构进行解剖学观测。所得数据用SPSS10．0软件进行统计学分析。结果MIP三维重建能满意显示两侧内耳膜迷路及内耳道的解剖结构,其中3个膜半规管、椭圆囊、球囊、蜗管及内耳道呈高信号。测量结果内耳主要结构均无显著的侧别差异。结论临床MIP三维重建能直观、立体地显示内耳膜迷路及内耳道的结构,为成年国人内耳主要结构MRI正常解剖测量值的确立提供了一定的基础资料。     

1.5T MRI常规序列及水成像用于儿童内耳畸形的诊断价值

目的探讨MRI在儿童内耳畸形中的应用价值。方法选择2013年7月至2015年12月在深圳市龙华新区人民医院和北京大学深圳医院诊治的疑似内耳畸形患儿30例(60耳),其中男性13例,女性17例;年龄1~14岁,平均年龄9岁。选择6例内耳正常志愿者(对照组),其中男性3例,女性3例;年龄1~16岁,平均年龄10岁。采用Philips Achieva 1.5 T MRI扫描仪对临床拟诊为感音性神经性耳聋(SNHL)患儿进行蜗神经MRI成像和内耳水成像,正常志愿者进行MRI对照检查。结果 30例患儿中,内耳重型畸形9例(30%)(Michel畸形4例7耳,Mondini畸形2例4耳,蜗神经缺如3例5耳);内耳相对轻型畸形21例(70%)(共腔畸形2例4耳,蜗管发育不全性聋2例4耳,Scheibe型畸形5例10耳,前庭导水管扩大10例19耳,内听道畸形而耳蜗及蜗神经发育正常或不良2例3耳)。其中含有3例两组交叉复合畸形即左右耳分别为重型和相对轻型内耳畸形。结论 MRI较为准确判断患儿内耳畸形、蜗神经发育状况,并可对畸形轻重程度分类,可为人工耳蜗植入适应证与禁忌证提供影像证据,在诊断SNHL中发挥着重要价值。     

正常踝关节的高场强磁共振成像扫描

目的:探讨正常踝关节高场强磁共振(MR)扫描技术.方法:6例人踝关节新鲜标本磁共振成像(MRI)扫描,应用两种不同的扫描条件分别行T1加权像(T1WI)、T2加权像(T2WI)、质子密度加权(PDW)、T2WI脉冲序列(SPAIR)冠状位、水平位,T2WI快速梯度回波(FFE)矢状位扫描.结果:在高场强的MRI运用小视野(FOV)(130 mm)、薄层扫描(2.0/1.0)、较大矩阵(410×510)及运用表面柔性线圈可提高踝关节MRI的分辨率.T1WI及PDW可提供最佳的解剖结构;提示T2WI能清晰地显示病变组织;提示SPAIR成像可良好地显示骨及软骨病变及区分脂肪组织内病变结构.结论:高场强MRI扫描是踝关节的理想影像学检查方法.     

先天性内耳发育畸形的高分辨率CT表现

目的探讨先天性内耳畸形的高分辨率CT表现。方法回顾性分析29例(46耳)婴幼儿先天性内耳发育畸形患者的CT表现,所有患者均做多层螺旋高分辨率CT横断面扫描及多平面重建,必要者利用容积再现技术对骨迷路进行三维重建。结果29例先天性内耳发育畸形患者双侧畸形者17例,单侧畸形者12例,内耳发育畸形共计46耳。具体分布如下:(1)Michel型(2耳),(2)耳蜗未发育(6耳),(3)共同腔畸形(5耳),(4)不完全分隔Ⅰ型(5耳),(5)不完全分隔Ⅱ型(传统Mondini型)(17耳),(6)耳蜗形态正常仅前庭及(或)半规管畸形(9耳),(7)单纯内耳道畸形(2耳)。结论高分辨率CT对先天性内耳骨迷路畸形具有重要的诊断价值,并可为人工耳蜗植入术适应证的选择提供重要依据。     

正常人内耳MR成像观察及测量研究

目的 :为内耳疾病的定位诊断和显微手术提供正常人内耳的MRI图像及解剖学数据。方法 :选择 33例无任何耳部疾病的正常志愿者 ,采用MRI技术对两侧内耳同时进行三维重建成像 ,观察其形态结构 ,3个半规管和内听道进行测量。结果 :(1) 33例均能满意显示两侧内耳的解剖结构 ,前庭、耳蜗、半规管、内听道显示清晰。 (2 ) 3个半规管内周长、外周长、管腔面积均以后半规管最长 ,上半规管次之 ,外半规管最短。 (3) 3个半规管脚间距以上半规管最大 ,外半规管次之 ,后半规管最小。 (4 ) 3个半规管壶腹端直径均大于 2mm ,外半规管单脚端直径为 (1.37±0 .34)mm ,上、后半规管总脚端直径为 (1.73± 0 .15 )mm。 (5 )内听道四壁中以前壁最长 ,后壁最短。内耳门处上下径小于前后径 ;内听道面积为 35 .4 5mm2 。结论 :利用MRI技术能立体而直观地显示内耳的细微结构。     

脑干薄层3D-TOF磁共振扫描在原发性三叉神经痛的诊断价值

目的 三叉神经根部与周围血管关系的临床意义.方法 观察脑干薄层3D-TOF扫描的病例150例,MR 检查采用SIMENS3.0T磁共振机,使用头部8 通道线圈平扫,采用3DTOF 扫描程序,扫描参数:TR 23 ms,TE 3.6 ms,翻转角15°,FOV 165×220,层厚1 mm.统计分析了三叉神经痛组69例及...     

Noninvasive Technique for Monitoring Drug Transport Through the Murine Cochlea using Micro-Computed Tomography

Local delivery of drugs to the inner ear has the potential to treat inner ear disorders including permanent hearing loss or deafness. Current mathematical models describing the pharmacokinetics of drug delivery to the inner ear have been based on large rodent studies with invasive measurements of concentration at few locations within the cochlea. Hence, estimates of clearance and diffusion parameters are based on fitting measured data with limited spatial resolution to a model. To overcome these limitations, we developed a noninvasive imaging technique to monitor and characterize drug delivery inside the mouse cochlea using micro-computed tomography (μCT). To increase the measurement accuracy, we performed a subject-atlas image registration to exploit the information readily available in the atlas image of the mouse cochlea and pass segmentation or labeling information from the atlas to our μCT scans. The approach presented here has the potential to quantify concentrations at any point along fluid-filled scalae of the inner ear. This may permit determination of spatially dependent diffusion and clearance parameters for enhanced models.     

Multidetector row CT demonstration of inner and middle ear structures

The aim of this study is to evaluate the anatomical details of the inner ear and middle ear, using multidetector row CT. Temporal bone CT scans were obtained using 16-detector row CT scanner (Lightspeed 16, General Electric Medical Systems, Milwaukee, WI) in 30 patients with dizziness, vertigo, or hearing loss. The three-dimensional (3D) images were reconstructed with volume rendering techniques. The 3D images were reviewed by two radiologists and scored by using a three-point quality rating for qualitative assessment of the 23 representative structures of the middle and inner ear. The malleus, incus, and facial nerve canal were identified in all patients. The incudomalleolar joint appeared fused in all patients. The stapes were seen clearly in 27 (90%) of 30 patients except in three patients. Among the three remaining patients, there was one who had effusions in the middle ear cavity. Another patient had left cholesteatoma. The third patient had normal middle ear cavity. The cochlea and the three semicircular canals (anterior, posterior, and lateral) were well demonstrated in 29 (97%) of 30 patients except for one old woman with osteoporosis. Sixteen-detector row CT imaging of temporal bone with advanced 3D reformation yields state-of-the-art anatomical details of the temporal region useful to address anatomical localization issues and ease conceptual structural learning.     

Minimization of over-ranging in helical volumetric CT via hybrid cone beam image reconstruction--benefits in dose efficiency

Diagnostic computed tomography (CT) images are usually acquired in both helical and axial scans in the clinical applications using cone beam volumetric CT. In addition to faster patient throughput, a helical scan in volumetric CT can provide better image quality because of the satisfaction of data sufficiency condition, and thus has been performed far more frequently so far in the clinic. However, the first and last images in a helical scan are usually prescribed at the locations that are half helical turn indented from the starting and ending points of the scan. Due to such an indention, the dose efficiency of helical scan deteriorates with increasing detector dimension along z direction. To improve the dose efficiency of helical scan in volumetric CT, a hybrid helical cone beam filtered backprojection (CB-FBP) algorithm is presented here to reconstruct helical images beyond the conventional indented image zone. The hybrid algorithm is a combination of the ray-wise three-dimensional (3D) weighted CB-FBP algorithms that are recently proposed for helical and axial CB image reconstructions. Through the hybridization, the ray-wise 3D weighting becomes dependent on both helical pitch and image slice location. Phantom study shows that the conventional indented image zone in helical scan can be extended substantially by using the hybrid algorithm. Consequently, the dose efficiency of volumetric CT in helical scan can be improved significantly. It is believed that, with increasing detector dimension along z direction in cone beam volumetric CT, the hybrid algorithm will become more attractive in clinical applications.     

The tibial tuberosity-trochlear groove distance; a comparative study between CT and MRI scanning

CT scan is the gold standard for the measurement of the tibial tuberosity-trochlear groove distance (TTTG). The aim of this study was to evaluate the reliability of the TTTG on MRI compared to CT scan. Twelve knees in 11 patients underwent CT and MRI examination for patellofemoral instability or anterior knee pain. Both the bony and the cartilaginous landmarks of the trochlear groove were used for the measurement of the TTTG. The measurements were performed by two experienced musculoskeletal radiologists. The interrater, intermethod and interperiod reliability was calculated using a restricted maximum likelihood estimation and a Bland-Altman analysis. The mean TTTG referenced on bony landmarks was 14.4+/-5.4 mm on CT scans, and 13.9+/-4.5 mm on MR images. The mean TTTG referenced on cartilaginous landmarks was 15.3+/-4.1 mm on CT scans, and 13.5+/-4.6 mm on MR images. An excellent interrater (82%), intermethods (86%), and interperiod (91%) quantitative reliability was found. TTTG can be determined reliably on MRI using either cartilage or bony landmarks. Additional CT scans are not necessary.     

The role of the computerized tomography scanner in the cross-transmission of carbapenem-resistant Acinetobacter baumannii between hospitalized patients

ObjectiveTo assess the role of the computerized tomography (CT) scanner in cross-transmission of carbapenem-resistant Acinetobacter baumannii between hospitalized patients undergoing CT scan.MethodsA single-centre retrospective observational analysis of inpatients undergoing CT scans. Patient-unique CT scans were defined as ‘index cases’ (patients undergoing CT scan with carbapenem-resistant Acinetobacter baumannii (CRAB) colonization documented during the previous 60 days), ‘incident cases’ (patients found colonized with CRAB within 14 days following CT scan), and ‘negative cases’ (negative for CRAB before and after CT scan). CRAB acquisition was analysed by time interval between CT scan and CT scan of the prior index-case patient.ResultsAmongst 73 047 CT scans performed over 5 years, 4834 scans were performed within 12 hours of an index case. CRAB acquisition was detected in 20 patients (incident cases), including 16/2725 (5.8/1000 scans) who underwent CT scan within 6 hours of an index-case CT scan and 4/2109 (1.9/1000 scans) who had their CT scan 7–12 hours after the CT scan of an index-case patient (p 0.033, risk ratio 3.1, 95%CI 1.03–9.25). Patient characteristics for the two time periods were similar. While not the only significant predictor of CRAB acquisition (others included age and length of hospital stay prior to the CT scan), the time elapsed from an index case remained a significant predictor for CRAB acquisition on multivariate analysis (OR 0.84, 95%CI 0.74–0.95, p 0.007).ConclusionsPerforming a CT scan within 6 hours of a CT scan performed in a CRAB-positive patient was an independent predictor of CRAB acquisition, approximately tripling the risk. This probably reflects poor infection control practice in the CT suite.     

Influence of phantom diameter,kVp and scan mode upon computed tomography dose index

The computed tomography (CT) radiation dose to pediatric patients has received considerable attention recently. Moreover, it is important to be able to determine CT radiation doses for various patient sizes ranging from infants to large adults. The current AAPM protocol only measures CT radiation dose using a 16 cm acrylic phantom to represent an adult head and a 32 cm acrylic phantom to represent an adult body. The goal of this paper is to study the dependence of the computed tomography dose index (CTDI) upon the size of the phantom, the kVp selected and the scan mode employed. Our measurements were done on phantom sizes ranging from 6 cm to 32 cm. The x-ray tube potential ranged from 80 to 140 kVp. The scan modes utilized for the measurements included: consecutive axial scans, single-slice helical scans with variable pitch and multislice helical scans with variable pitch. The results were consolidated into simplified equations which related the phantom diameter and kVp to the measured CTDI. Some generalizations were made about the relationship between the scan modes of the various CT units to the measured radiation doses. The CTDI appears to be an exponential function of phantom diameter. For the same kVp and mAs, the radiation doses for smaller phantoms are much greater than for larger sizes. The derived relationship can be used to estimate the radiation doses for a variety of scan conditions and modes from measurements with the two standard reference phantoms. A method was also given for converting axial CT dose measurements to appropriate MSAD values for helical CT scans.     

正常中耳腔的CT仿真内窥镜技术

目的：探讨正常听骨链的CT仿真内窥镜(CTVE)成像技术方法及其对中耳结构显示程度。方法：15例无中耳疾病的健康人，层厚1mm、螺距1．0轴位薄层扫描，骨算法、0．1～0．2mm间隔重建，行CTVE成像，观察正常听骨链的情况。结果：采用CTVE技术，对锤骨、砧骨及锤砧关节及砧镫关节的显示率均能清晰的显示，砧镫关节呈“L”形。但镫骨底板和镫骨的前、后脚显示欠佳，约有1／3可以显示。结论：CTVE成像技术能很好地显示中耳腔内部的听骨链立体结构，特别是可以部分显示镫骨底板，该技术将在活体上对中耳腔形态及功能的研究有重要意义。     

Inner ear abnormalities in Kabuki make-up syndrome: report of three cases

Three patients, a female and two males, 28, 15, and 14 years of age, with Kabuki make-up syndrome (KMS) were studied for middle and inner ear abnormalities by using CT scanning of the petrous bones. All three patients had bilateral dysplasia of the inner ear, i.e., hypodysplasia of the cochlea, vestibule, and semicircular canals (so-called Mondini dysplasia), whereas their middle ears had no abnormalities. Audiometry demonstrated a sharp decrease in hearing of the high tone range, bilateral in one and unilateral in another, while the third patient was noncooperative. In view of these findings, it would be advisable to study each individual with KMS and hearing impairment for possible inner ear abnormalities.