正常新生儿脑容积的MSCT测量

目的:观测正常新生儿脑容积,为新生儿颅脑疾病的诊断提供正确的CT解剖数据。方法:从行颅脑CT扫描的新生儿中选取42例无异常发现者的CT图像进行测量,利用容积测量软件,用等灰度法均匀涂布所选区域,测量项目为脑容积9项。结果:获得新生儿脑容积9项指标的平均值,全脑容积(419.15±5.33)cm3,左侧大脑半球容积(187.62±2.91)cm3,右侧大脑半球容积(187.61±3.38)cm3,左侧小脑半球容积(17.15±1.05)cm3,右侧小脑半球容积(16.99±0.85)cm3,左侧侧脑室容积(3.76±0.07)cm3,右侧侧脑室容积(3.75±0.08)cm3,第三脑室容积(0.22±0.01)cm3,第四脑室容积(0.24±0.01)cm3,左右大脑半球容积、左右小脑半球容积及左右侧脑室容积差异无显著性(P均>0.05)。结论:MSCT可准确测量正常活体新生儿脑容积,从影像学角度认识正常新生儿脑容积的解剖。     

骨质疏松老年妇女腰椎骨密度及结构的多层螺旋CT研究

目的评价容积性定量CT(vQCT)技术测量的腰椎骨密度(BMD)参数区分骨质疏松性椎体骨折与无骨折老年妇女的能力,对骨质疏松老年妇女腰椎结构与正常老年妇女进行比较。方法将有骨质疏松脊椎骨折的26例老年妇女归为第1组,选择年龄与其相匹配的无脊椎骨折的30例骨质疏松妇女归为第2组。应用多层螺旋CT(MSCT)对56例病人腰椎L1、L2椎体行容积扫描,在横断面影像中经传统的QCT法测量L1、L2小梁骨BMD(2D-TRAB)、整体骨BMD(2D-INTGL);在经计算机工作站行容积再现(VR)三维处理的影像中应用直方图功能测量L1、L2椎体整体骨BMD(3D-INTGL)、皮质骨BMD(3D-CORT)、小梁骨BMD(3D-TRAB)。双能X线吸收仪(DXA)测量参数为腰椎正位BMD(AP-SPINE)、腰椎正位表观BMD(BMAD)。比较2组老年妇女间上述7组的BMD值。另对10例2D-TRAB正常的老年妇女在VR像中测量L1椎体中部边长为20mm的正方体内骨小梁容积比值,并与在56例妇女中随机选取的10例的数值比较。结果DXA测量中AP-SPINE、BMAD在第1组妇女为(0·796±0·170)g/cm2、(272·7±27·7)mg/cm3,与第2组妇女(0·817±0·140)g/cm2、(249·5±26·5)mg/cm3之间差异无统计学意义;vQCT中第1组的2D-TRAB为(70·4±22·2)mg/cm3、2D-INTGL为(138·3±35·1)mg/cm3、3D-INTGL为(139·4±34·9)mg/cm3、3D-CORT为(133·8±26·9)mg/cm3、3D-TRAB为(69·9±18·6)mg/cm3,比第2组数值(89·1±21·8)mg/cm3、(170·6±34·5)mg/cm3、(180·5±28·2)mg/cm3、(163·2±27·5)mg/cm3、(83·8±17·1)mg/cm3下降18%~23%。10例骨质疏松老年妇女L1椎体骨小梁容积比值为(8·12±1·96)%,明显低于正常老年妇女的(39·13±2·15)%,差异有统计学意义(P<0·01)。结论MSCT中vQCT参数区分骨质疏松性椎体骨折与无骨折老年妇女的能力优于DXA,三维重组影像显示的骨质疏松老年妇女椎体骨小梁容积明显低于正常老年妇女。     

CT定量研究衰老时脑萎缩

作者选择483名男性和497名女性,年龄10～88岁,每10岁分组,包括高血压,糖尿病,肺病和肾病患者作CT 检查,均无神经学缺陷。颅腔和脑脊液(CSF)间隙容积测量:平均CT值,脑室7.9±0.8(6例),白质29.3±1.7(64例),灰质35.5±1.5(64例),与年龄变异无关。     

创伤后应激障碍的海马容积和氢质子波谱研究

目的运用MRI研究创伤后应激障碍(PTSD)海马的容积和波谱改变,探讨PTSD海马损伤可能存在的病理生理机制。方法17例PTSD患者和17例年龄匹配的健康志愿者(对照组),用1.5T超导MR扫描系统进行MRI及双侧海马多体素氢质子波谱(1HMRS)采集,测定N乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)代谢物浓度,各代谢物水平的测定以波谱覆盖的面积为准。用容积分析软件测量海马和颅内容积大小,并根据颅内容积的大小对海马容积进行标准化处理。把PTSD组代谢物的浓度和海马的容积分别和对照组进行配对比较。结果PTSD组左右侧海马的容积分别是(2130±221)mm3、(2571±190)mm3,对照组左右侧海马的容积分别是(2382±157)mm3、(2572±186)mm3,左侧海马的容积与健康对照组左侧海马容积差异有统计学意义(P<0.001);右侧海马容积两组间差异无统计学意义(P>0.05)。PTSD组两侧海马NAA和Cr均明显下降(左侧:NAA为2.8±0.7,Cr为2.3±0.6;右侧:NAA为2.9±0.9,Cr为2.3±0.7),与对照组(左侧:NAA为3.8±0.8,Cr为2.7±0.5;右侧:NAA为3.9±0.8,Cr为2.8±0.5)差异均具有统计学意义(P<0.05)。Cho两组两侧差异均无统计学意义(P>0.05)。结论结果支持海马参与了PTSD的病理生理过程,海马容积和(或)代谢的改变对PTSD的临床诊断和PTSD海马损伤的病理生理机制的探讨具有重要的价值。     

MR流体定量技术在脑脊液循环障碍疾病诊断中的应用

目的:无创性定量研究脑脊液循环改变及其临床意义。材料和方法:应用MR相位对比电影法,测定了15例正常志愿者,67例脑脊液循环障碍患者(交通性脑积水32例、阻塞性脑积水31例、Chiaril畸形4例)以及15例脑萎缩患者的中脑导水管、C2水平及部分第三脑室底部造瘘口水平的脑脊液动力学指标(峰值流速、流量及CSF流动波型)。结果:(1)正常志愿组中脑导水管脑脊液流动在一个心动周期内均表现为双向流动,即收缩期向下流动和舒张期向上流动,向下及向上峰速分别为12.60±4.42mm/s和10.10±3.58mm/s;(2)交通性脑积水组脑脊液循环表现为高动力学改变,向下及向上峰速分别为26.60±9.06mm/s和22.61±7.92mm/s,与正常志愿组比较有显著差异(P<0.05)。脑积水分流前后比较导水管循环减慢者提示有效;阻塞性脑积水组表现为低动力学或流动波消失,2例行第三脑室造瘘者导水管流动不规则,造瘘口出现上下流动现象;Chiaril畸形组C2水平脊髓后间隙缩小,流动减慢,脊髓前间隙增宽,1例合并空洞者囊腔内出现高动力学改变;(3)脑萎缩组表现为低动力学改变,向下及向上峰速分别为11.71±4.75mm/s和8.54±3.08mm/s,与正常志愿组、交通性脑积水组比较均有显著差异(P<0.05)。结论:MR相位对比电影法可有效评价脑脊液循环动力学改变,可丰富脑脊液循环     

100例正常人脑底动脉直径的MR血管成像测量

目的　测量并建立国人正常脑底动脉直径磁共振血管成像 (MRA)正常值。方法　常规MR检查脑实质及脑动脉三维时间飞越法 ( 3DTOF)MRA检查脑底动脉表现无异常者 10 0例 ,其中男5 3例 ,女 47例 ,年龄 4～ 75岁 ,平均 45 8岁 ;≤ 14岁者 12例 ,>14岁者 88例。采用投影仪放大胶片间接测量法测量各脑动脉直径 ,分析其左右侧、年龄和性别上的差异性 ,并统计出各动脉直径的正常参考值。结果　各脑动脉直径测量值为 :眼动脉 (OphA)男为 ( 0 8± 0 2 )mm ,女为 ( 0 9± 0 2 )mm ;颈内动脉 (ICA)C2段男为 ( 3 0± 0 3)mm(≤ 14岁 )和 ( 3 5± 0 6 )mm( >14岁 ) ,女为 ( 2 8± 0 6 )mm(≤14岁 )和 ( 3 1± 0 5 )mm( >14岁 ) ;ICAC4段男为 ( 4 3± 0 6 )mm ,女为 ( 3 9± 0 6 )mm ;大脑前动脉(ACA)A1段男为 ( 2 1± 0 4)mm ,女为 ( 2 1± 0 4)mm ;前交通动脉 (ACoA)男为 ( 1 4± 0 4)mm ,女为( 1 3± 0 4)mm ;大脑中动脉 (MCA)M1段男为 ( 2 7± 0 4)mm ,女为 ( 2 6± 0 4)mm ;基底动脉 (BA)男为 ( 2 9± 0 5 )mm ,女为 ( 2 8± 0 4)mm ;大脑后动脉 (PCA)P1段男左为 ( 2 1± 0 5 )mm、右为 ( 2 0±0 5 )mm ,女左为 ( 2 0± 0 3)mm、右为 ( 1 9± 0 3)mm ;PCAP2段男为 ( 1 8± 0 4)mm     

正常成人垂体的磁共振测量研究

目的:观察正常垂体形态、测量其大小并探讨其与年龄、性别的变化关系。方法:选取300例非鞍区病变及内分泌症状的正常成年人。按性别、年龄分为5组:20~29岁组,30~39岁组,40~49岁组,50~59岁组及60岁以上组,每组男女各30例,MRI测量矢状位腺体及后叶前后径、高径以及垂体柄前后径;冠状位腺体宽径、高径及垂体柄宽径;比较分析不同性别、年龄段上述各径线MR测量值的变化特点。结果:成人男、女正常垂体冠状高径分别为(4.01±1.08)mm、(3.99±1.37)mm,冠状宽径分别为(9.75±1.63)mm(、10.17±1.59)mm;矢状高径分别为(4.46±1.24)mm(、4.68±1.61)mm;前后径分别为(10.15±1.51)mm(、10.24±0.90)mm;垂体后叶矢状高径分别为(4.01±1.43)mm(、4.59±1.17)mm,前后径分别为(2.01±0.66)mm、(1.98±0.70)mm;垂体柄冠状宽径分别为(1.56±0.21)mm、(1.59±0.21)mm,前后径分别为(1.50±0.23)mm、(1.52±0.22)mm。垂体高径在20~29年龄组最大,有随年龄增大而逐渐减小趋势;垂体宽径及前后垂体后叶及垂体柄各径线有先增大后减小趋势。结论:成人垂体各径线随年龄的变化有先变大后减小趋势。各径线与年龄有一定统计学差异而与性别无明显统计学差异。     

基于CT图像的纹理分析对体外冲击波碎石术疗效的预测价值

【摘要】目的：探讨基于CT图像的纹理分析对体外冲击波碎石术（ESWL）疗效的预测价值。方法：回顾性分析82例进行ESWL碎石的患者的病例资料，男63例，女19例，评估性别、年龄、结石位置、体重指数（BMI）、结石最大长径及最大横径、45°结石距体表距离（SSD）、平均CT密度值及CT纹理分析定量参数平均灰度值、标准差、偏度、峰度、熵、异质性对碎石结果的影响。依据治疗后残余结石是否＜4mm将患者分为碎石成功组及失败组，对比两组间各纹理参数的特征及不同参数组合预测碎石效果的效能。结果：碎石成功组与碎石失败组的平均CT值［(699.47±176.32)HU，(848.48±191.69)HU，t=-3.495，P＜0.01］、CT纹理参数平均灰度值（1723.47±176.32，1872.48±191.69，t=-3.495，P＜0.01）、峰度（-0.82±0.34，-1.07±0.28，t=3.400，P＜0.01）及熵（4.26±0.87，4.76±0.44，t=-2.809，P＜0.01）的差异具有统计学意义，平均灰度值、峰度以及参数组合平均灰度值+标准差、平均灰度值+熵、平均灰度值+标准差+熵、偏度+峰度、峰度+异质性、偏度+峰度+异质性的组合预测碎石效果的效能良好（0.7＜AUC＜0.9），余各纹理参数的AUC均在0.5～0.7之间，预测碎石效果的效能一般。结论：CT纹理分析定量参数有助于预测ESWL碎石疗效。     

脑肿瘤的多层螺旋CT灌注成像初步研究

目的运用多层螺旋CT(MSCT)获取脑肿瘤的灌注图像,评估CT灌注成像对脑肿瘤的诊断价值。方法对38例脑肿瘤患者行MSCT灌注成像,采用电影模式(1 s/周),扫描层厚5 mm,共4层,80 kV,200 mA,重组层厚10 mm,共2层。采用高压注射器注射非离子型碘对比剂50 ml (300 mg I/ml),流率3．5 ml/s,延迟5 s,数据采集45 s。38例脑肿瘤包括9例Ⅰ～Ⅱ级星形细胞胶质瘤(组1),10例Ⅲ～Ⅳ级星形细胞胶质瘤(组2),9例转移瘤(组3),10例脑膜瘤(组4)。分别测量38例脑肿瘤的血流量(BF)、血容积(BV)、表面通透性(PS),并进行统计学分析。结果组1～4的(BF)~(1/2)分别为(5．99±1．03)、(7．55±1．57)、(7．72±2．02)、(11．40±2．13)ml·min~(-1)·kg~(-1)；组1与组2比较t=6．89,组1与组3比较t=4．59,组1与组4比较t=11．03,组2与组4比较t=10．58,组3与组4比较t=7．65,P值均＜0．05；组2与组3比较t=1．17,P＞0．05。组1～4的(BV)~(1/2)分别为(1．01±0．19)、(1．42±0．38)、(1．25±0．33)、(1．60±0．24)ml·kg~(-1)；组1与组2比较t=7．15,组1与组3比较t=3．71,组1与组4比较t=5．93,组2与组3比较t=2．94,组2与组4比较t=2．72,组3与组4比较t=4．46,P值均＜0．05。组1～4的(PS)~(1/2)分别为(1．70±0．37)、(3．63±0．95)、(4．29±1．30)、(5．69±1．03)ml·min~(-1)·kg~(-1)；组1与组2比较t=11．53,组1与组3比较t=10．61,组1与组4比较t=16．77,组2与组3比较t=3．69,组2与组4比较t=9．94,组3与组4比较t=5．52,P值均＜0．05。结论MSCT脑灌注成像能科学地量化脑肿瘤的血液动力学改变,并有助于肿瘤的术前分级、原发与转移性恶性肿瘤的判断以及脑内与脑外肿瘤的鉴别诊断。     

多层螺旋CT计算心室容积的准确性及最佳层厚选择

目的(1)确定Simpson方法计算心室容积的最佳层厚;(2)评价多层螺旋CT计算心室容积的准确性。方法采用多层螺旋CT(东芝Aquilion)扫描系统对14个人的左室铸型和15个右室铸型进行扫描。分别以2.0、3.5、5.0、7.0及10.0mm层厚重建左、右心室短轴多平面重组(multiplanarreformattedimage,MPR)图像。采用标准Simpson法计算左、右心室铸型的容积。心室铸型的实际容积通过铸型排除水的容量来计算。结果各层厚计算的心室容积均高估相应心室的实际容积[左心室高估值介于(3.21±5.95)ml至(12.58±8.56)ml之间,右心室高估值介于(10.22±8.45)ml至(23.91±12.24)ml之间]。各层厚计算的心室容积均与相应的实际心室容积高度相关(左心室r值均>0.97,右心室r值均>0.95);心室容积的高估程度与选择的层厚呈显著正相关(左心室r=0.998,右心室r=0.996)。当层厚降至5mm时,计算的心室容积对实际容积的高估值与2mm层厚相比不再差异有统计学意义。结论采用多排Simpson法计算左、右心室容积时,5mm层厚是最有效率的层厚。MSCT可以准确计算左、右心室容积。     

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.     

Controversies in cervical spine imaging in trauma patients

No area of emergency radiology has generated as much discussion in recent years as the subject of cervical spine imaging for trauma patients. This review will be in three parts. The first will examine the indications for cervical imaging and will focus on those factors that make patients at high risk or low risk for cervical injury. The second part will discuss the merits of radiography and computed tomography as the main screening diagnostic examination. In addition to the roles of each modality in the evaluation process, such factors as efficacy of diagnosis, time (duration) of study, and cost will be discussed. Finally, the third part will explore the methods currently employed to clear the cervical spine in comatose patients.Presented at the Annual Meeting of the American Society of Emergency Radiology, Las Vegas, Nevada, 22–25 October, 2003     

Uterine contractions: Possible diagnostic pitfall at MR imaging

A total of 206 nongravid patients with various gynecologic problems underwent pelvic magnetic resonance (MR) examinations that included both sagittal T2-weighted and contrast agent–enhanced T1-weighted images. MR images were retrospectively reviewed to identify changes in endometrial configuration on serial images obtained during the same MR examination. In 20 MR examinations (all in women of reproductive age), endometrial distortion due to myometrial bulging was noted on T2-weighted or contrast-enhanced T1-weighted images. It was absent on other MR images obtained at different times. Myometrial bulging exhibited low signal intensity in 18 examinations. The finding resembled adenomyosis or leiomyoma on T2-weighted or contrast-enhanced T1-weighted images. These results evidence the presence of transient myometrial bulging and transient low-intensity myometrium in the nongravid uterus. This phenomenon is thought to represent uterine contraction. Clinicians should be aware of the potential presence of transient low-signal-intensity myometrial bulging that could present diagnostic problems in the normal uterus.     

Brodie Abscess: MR imaging appearance in 10 patients

The magnetic resonance (MR) imaging features of Brodie abscess have not yet been fully evaluated. Ten patients with Brodie abscess, eight of long bone and two of vertebra, were studied with MR imaging. Long bone abscess had a characteristic “target” appearance with four layers: (a) a center with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR (short-inversion-time inversion recovery) images, (b) an inner ring isointense to muscle on T1-weighted images and with high signal intensity on T2-weighted and STIR images, (c) an outer ring hypoin-tense on all images, and (d) a peripheral halo hypointense on T1-weighted images. In six of eight cases, a soft-tissue mass was found. The two vertebral abscesses had a less specific appearance, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR images. Only the peripheral halo was clearly identified in both cases.     

Right-side aortic arch with aneurysm of aberrant left subclavian artery: MR imaging appearance.

Reports of aneurysms of the subclavian artery in both normal and anomalous aortic arches have been rare. The authors describe a patient with a right-side aortic arch and an aneurysm of the aberrant left subclavian artery, which, to the authors' knowledge, is a previously unreported association. At presentation, the aneurysm appeared as a calcified left superior mediastinal mass. Magnetic resonance imaging enabled preoperative diagnosis and guided surgical planning.     

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.     

Adrenal tissue characterization with 0.5-T MR imaging: Value of T2*-weighted images

The authors investigated the value of magnetic resonance (MR) imaging at 0.5 T for distinguishing adrenal adenomas from adrenal metastases. The series included 23 adrenal adenomas (18 nonhyperfunctioning, five hyperfunctioning) and 23 adrenal metastases from various organs. Adrenal tumor–liver signal intensity ratios on T1-, T2-, and T2*-weighted images were calculated for adrenal tissue characterization. Adrenal adenomas were more precisely distinguished from adrenal metastases on T2*-weighted images (21 of 23, 91%) than on T2-weighted images (15 of 23, 65%). T1-weighted images were not useful for this distinction. In conclusion, T2*-weighted images were better than routine T2-weighted images for distinguishing adrenal adenomas from adrenal metastases. It can be postulated that the total signal intensity of adrenal adenomas, which contain some fat components, decreased on T2*-weighted images because of an out-of-phase effect.     

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.