Development of automatic extraction of the corpus callosum from magnetic resonance imaging of the head and examination of the early dementia objective diagnostic technique in feature analysis

We examined the objective diagnosis of dementia based on changes in the corpus callosum. We examined midsagittal head MR images of 17 early dementia patients (2 men and 15 women; mean age, 77.2+/-3.3 years) and 18 healthy elderly controls (2 men and 16 women; mean age, 73.8+/-6.5 years), 35 subjects altogether. First, the corpus callosum was automatically extracted from the MR images. Next, early dementia was compared with the healthy elderly individuals using 5 features of the straight-line methods, 5 features of the Run-Length Matrix, and 6 features of the Co-occurrence Matrix from the corpus callosum. Automatic extraction of the corpus callosum showed an accuracy rate of 84.1+/-3.7%. A statistically significant difference was found in 6 of the 16 features between early dementia patients and healthy elderly controls. Discriminant analysis using the 6 features demonstrated a sensitivity of 88.2% and specificity of 77.8%, with an overall accuracy of 82.9%. These results indicate that feature analysis based on changes in the corpus callosum can be used as an objective diagnostic technique for early dementia.     

阿尔茨海默病与血管性痴呆的胼胝体MR定量研究

目的　比较MR影像上阿尔茨海默病 (Alzheimer′sdisease ,AD)组、血管性痴呆 (vasculardementia ,VD)组、正常对照 (normalcontrol,NC)组胼胝体面积及胼胝体不同部位的厚度 ,为进一步探讨AD、VD的发病机理提供参考。方法　本研究 70例中AD 2 6例 ,VD 14例 ,年龄匹配的正常对照 3 0例。行磁共振扫描 ,取T1WI正中矢状面测量胼胝体面积及胼胝体前、前中、中、中后、后 5个部位的厚度。结果　AD组与VD组及NC组胼胝体标准化面积分别为 :(3 5 5± 0 5 2 )cm2 ;(3 48± 0 90 )cm2 ;(4 2 3± 0 43 )cm2 。AD组与VD组及NC组胼胝体前、前中、中、中后、后 5个部位标准化厚度分别为 :AD (5 3 4± 1 14)mm ,VD (5 5 3± 1 86)mm ,NC (7 0 6± 1 11)mm ;AD (2 5 3± 0 62 )mm ,VD (2 5 3±0 86)mm ,NC (3 46± 0 66)mm ;AD (2 85± 0 5 4)mm ,VD (2 84± 1 0 4)mm ,NC (3 5 4± 0 61)mm ;AD (2 0 1± 0 5 0 )mm ,VD (1 90± 0 72 )mm ,NC (2 49± 0 65 )mm ;AD (5 46± 0 96)mm ,VD (5 2 2±1 40 )mm ,NC (6 82± 1 0 2 )mm。AD组与VD组胼胝体前、前中、中、中后、后 5个部位的萎缩率分别为 :AD (2 4 3 6± 16 13 ) % ,VD (2 1 70± 2 6 3 5 ) % ;AD (2 6 75± 17 97) % ,VD (2 6 78± 2 4     

Factor analysis of medical image sequences in MR of head and neck tumors.

PURPOSETo evaluate factor analysis of medical image sequences (FAMIS), a means whereby physiologic contrast enhancement kinetics, called factors, and their spatial distribution, termed factor images, are estimated after acquisition of dynamic MR images. The method is intended to recognize and characterize the different tissue kinetics automatically.METHODSThis method was evaluated in a series of 22 patients with head and neck tumors. Eleven patients presented with a previously untreated lesion. Six were examined for tumor recurrence, previously treated by multiple therapies. Five patients had preoperative chemotherapy and underwent MR before and after chemotherapy. In all cases, MR images were correlated with surgical and pathologic data. MR examinations were performed on a 1.5-T unit with static sequences and dynamic sequences acquired after bolus injection of gadolinium and processed by FAMIS.RESULTSFAMIS was able to identify three factors representing contrast-enhancement kinetics and their associated factor images. The neoplastic component was associated with the earlier factor image, F1. Fibrosis and chemotherapy and/or radiation-induced changes were associated with the two later factors, F2 and F3. The limits of this method were highly vascularized tissues whose earlier factor was similar to that of neoplastic tissues (mucosae and salivary glands), patient motion, responsible for artifacts in FAMIS, and lesions of less than 5 mm.CONCLUSIONFAMIS of dynamic MR studies was useful for differentiating neoplastic tissue from tissue having undergone changes by chemotherapy and/or radiotherapy, but it did not improve the ability of MR to characterize neoplastic tissues in previously untreated patients.     

The normal and abnormal genu of the corpus callosum: an evolutionary,embryologic, anatomic,and MR analysis.

PURPOSETo define the normal and abnormal genu of the corpus callosum by examining its evolution and embryology and by analyzing its normal and abnormal appearance on MR images.METHODSA reference line was drawn from the mamillary body through the anterior commissure and corpus callosum-the MAC line. This line was used to evaluate the genu in adult mammal brains, in human fetal brains, on MR images of 1800 patients with normal corpora callosi, and on MR images of 113 patients with callosal anomalies.RESULTSIn primates, increased frontal lobe size is associated with an anteriorly shifted genu. In human fetal development, the anterior body of the corpus callosum develops before the definitive genu. The normal human genu always projects in front of the MAC line. In none of the 113 patients with callosal anomalies was there only a normal genu.CONCLUSIONSThe human corpus callosum develops bidirectionally, not from front to back. The MAC line is a useful frame of reference to study the evolution and embryology of the genu and to distinguish the normal from the abnormal genu of the human corpus callosum.     

健康成年人与血管性痴呆患者胼胝体及侧脑室体积的比较

目的：采用3.0T MRI对健康成年人及血管性痴呆患者胼胝体体积及侧脑室体积进行定量测量,探讨健康成年人不同年龄组、性别间胼胝体体积、侧脑室体积有无差别,并与血管性痴呆患者行对照研究。方法：选取健康成年人200例,男112例,女88例,年龄20-69岁,平均（42.81±13.43）岁;血管性痴呆患者31例,男15例,女16例,年龄45-86岁,平均（68.52±9.85）岁,采用3.0T MRI体积软件行侧脑室及胼胝体体积定量测量。结果：①健康成年人不同年龄组间侧脑室体积及胼胝体体积间均存在差别（P〈0.05）;②健康成年人男女不同性别间侧脑室体积及胼胝体体积之间比较差异亦具有统计学意义（P〈0.05）;③血管性痴呆患者组与老年健康对照组比较,侧脑室体积及胼胝体体积均有明显差别（P〈0.05）。结论：健康成年人60岁之前各年龄组间侧脑室体积无明显差别,60岁以后侧脑室体积扩大;健康成年人胼胝体体积在39岁之前随年龄增长有逐渐增大趋势,50岁以后体积逐渐萎缩,60岁后明显萎缩;男性侧脑室体积及胼胝体体积均较女性大;血管性痴呆组与老年健康对照组比较侧脑室明显扩大,胼胝体萎缩。     

MR imaging findings of the corpus callosum region in the differentiation between multiple sclerosis and neuromyelitis optica

Purpose

To evaluate MR imaging findings in corpus callosum region for the discrimination between opticospinal multiple sclerosis (OSMS) and neuromyelitis optica (NMO).

Materials and methods

Forty-two definite OSMS with seronegative NMO-IgG and 23 NMO with seropositive NMO-IgG, and 27 age-matched normal controls (NC) were recruited. Sagittal T2-FLAIR images with 2-mm slice thickness were obtained. Subcallosal dot-dash (SCDD) sign and subcallosal striations (SCS) sign were reviewed.

Results

SCDD was more commonly detected in OSMS (28 of 42 patients) than in NMO (5 of 23 patients) (P < 0.05). SCS showed no difference between OSMS (31 of 42 patients) and NMO (12 of 23 patients) (P > 0.05). For comparing ROC analysis among SCDD, SCS, and SCDD + SCS for predicted probability through binary logistic regression analysis, SCDD + SCS had the largest area under ROC curve (0.777) than SCDD (0.725) and SCS (0.608).

Conclusion

SCDD may be helpful in distinguishing OSMS from NMO. The regression equation may also be a simple and effective method of choice for the differentiation between OSMS and NMO.     

Endorectal MR imaging in the evaluation of seminal vesicle invasion: diagnostic accuracy and multivariate feature analysis

PURPOSE: To retrospectively determine the accuracy of endorectal magnetic resonance (MR) imaging in demonstrating seminal vesicle invasion (SVI) and to investigate the MR imaging features that can predict SVI. MATERIALS AND METHODS: The Institutional Review Board granted exempt status for this retrospective study, with waiver of informed consent; patient data were collected and handled in accordance with HIPAA regulations. Fifty-one men (age range, 44-73 years) with SVI and 303 men (age range, 40-76 years) without SVI who underwent endorectal MR imaging before radical prostatectomy between January 2000 and October 2004 were included in the study. Endorectal MR images were retrospectively and independently analyzed by two radiologists for SVI, tumor at prostate base, extracapsular extension, and other features considered indicative of SVI. Areas under the receiver operating characteristic curves (AUCs) were used to assess the accuracy of detecting SVI at endorectal MR imaging. A multiple logistic regression was used to explore the combinations of MR imaging features that might facilitate the detection of SVI. RESULTS: Readers 1 and 2 had an AUC of 0.93 and 0.81, respectively, for the detection of SVI. For both readers, the features that had the highest sensitivity and specificity were low signal intensity within the seminal vesicle and lack of preservation of seminal vesicle architecture. At multiple regression analysis, tumor at the prostate base that extended beyond the capsule and low signal intensity within a seminal vesicle that has lost its normal architecture were highly predictive of SVI. CONCLUSION: Endorectal MR imaging is accurate in demonstrating SVI prior to radical prostatectomy, and recognition of the most predictive features may facilitate the use of this modality.     

Correlation of diffusion tensor and dynamic perfusion MR imaging metrics in normal-appearing corpus callosum: support for primary hypoperfusion in multiple sclerosis

BACKGROUND AND PURPOSE: Hypoperfusion of the normal-appearing white matter in multiple sclerosis (MS) may be related to ischemia or secondary to hypometabolism from wallerian degeneration (WD). This study evaluated whether correlating perfusion and diffusion tensor imaging (DTI) metrics in normal-appearing corpus callosum could provide support for an ischemic mechanism for hypoperfusion. MATERIALS AND METHODS: Fourteen patients with relapsing-remitting MS (RRMS) and 17 control subjects underwent perfusion MR imaging and DTI. Absolute measures of cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) were calculated. Mean diffusivity (MD) and fractional anisotropy (FA) maps were computed from DTI data. After visual coregistration of perfusion and DTI images, regions of interest were placed in the genu, central body, and splenium of normal-appearing corpus callosum. Pearson product-moment correlation coefficients were calculated using mean DTI and perfusion measures in each region. RESULTS: In the RRMS group, CBF and CBV were significantly correlated with MD in the splenium (r = 0.83 and r = 0.63, respectively; both P < .001) and in the central body (r = 0.86 and r = 0.65, respectively; both P < .001), but not in the genu (r = 0.23 and 0.25, respectively; both P is nonsignificant). No significant correlations were found between MTT and DTI measures or between FA and any perfusion measure in the RRMS group. No significant correlations between diffusion and perfusion metrics were found in control subjects. CONCLUSION: In the normal-appearing corpus callosum of patients with RRMS, decreasing perfusion is correlated with decreasing MD. These findings are more consistent with what would be expected in primary ischemia than in secondary hypoperfusion from WD.     

CT与MR图像融合技术在听神经瘤检查中的初步应用

听神经瘤(acoustic neurinoma)发病率较高~([1]).治疗前的准确定性诊断及病变范围的精确勾画对临床治疗非常重要,影像检查主要依赖CT或MRI,由于CT、MRI对骨质和钙化、软组织的分辨率各有优势,笔者拟将同一患者的CT、MR图像进行融合,探讨CT与MR图像融合技术在听神经瘤检查中的应用价值.     

A computer system for image feature analysis of chest radiographs in CT-documented interstitial lung diseases]

This paper reports the clinical significance of a computer-analyzing system to detect and characterize interstitial lung diseases in chest radiographs. One hundred and sixty-four ROIs were selected in the right lungs of 41 patients with normal and those of 41 with diffuse interstitial involvement proved by X-ray CT. Selected ROIs were processed by 4-directional Laplacian-Gaussian filtering, binarization, and determination of linear shadows. For quantitative analysis of interstitial shadows, radiographic index, normalized percent-area of shadows in a ROI, was determined and evaluated in the images. Then, the radiographic indices were compared with CT-documented characteristics of interstitial lung shadows. The results were as follows: 1) Abnormal and normal lungs were well differentiated each other by all kinds of the radiographic indices obtained from the images filtered by 4-directional Laplacian-Gaussian filters and from those processed by determination of linear shadows. 2) ROIs with honeycombing shadows and with other interstitial shadows (interstitial changes other than honeycombing and nodulation) shown in CT were differentiated each other by the radiographic indices obtained from the summation image and the vertical directional image processed by determination of linear shadows (p less than .01). However, ROIs with multiple nodular shadows and with other interstitial shadows were not classified by these radiographic indices. These results indicate that this system may be useful for detection and characterization of interstitial diseases in chest radiographs.     

Transient focal lesion in the splenium of the corpus callosum: MR imaging with an attempt to clinical-physiopathological explanation and review of the literature

PURPOSE: This article discusses the possible pathophysiological conditions responsible for magnetic resonance imaging (MRI) finding of transient focal lesions in the splenium of the corpus callosum on the basis of our experience and a review of the literature. MATERIALS AND METHODS: In six patients undergoing computed tomography (CT) and MRI examinations, focal nonhemorrhagic lesions of the splenium of the corpus callosum were incidentally discovered. Patients had been referred for suspected encephalitis (n=2), dural sinus thrombosis (n=1) and multiple sclerosis (n=3). MRI examinations were repeated after 4, 8 and 12 weeks and in two cases also after 6 and 9 months. MRI and medical records were retrospectively reviewed with respect to patients' clinical history, medication and laboratory findings to define lesion aetiology. RESULTS: In all patients, the lesions were isolated, reversible and with no contrast enhancement. In four patients, the lesion disappeared after complete remission of the underlying disease, whereas in two patients, they persisted for 6 and 9 months, respectively. CONCLUSIONS: To our knowledge and according to previous reports, the fact that these lesions are detected in a relatively large number of conditions with heterogeneous etiopathogenetic factors leads to the hypothesis that a common underlying pathophysiological mechanism that, considering signal characteristic, reversibility and white matter location, could be represented by vasogenic oedema.     

Focal lesion in the splenium of the corpus callosum on FLAIR MR images: a common finding with aging and after brain radiation therapy

BACKGROUND AND PURPOSE: Focal high signal intensity in the splenium of the corpus callosum on fluid-attenuated inversion-recovery (FLAIR) images is generally considered an abnormal MR finding. We identified high signal intensity in the splenium on FLAIR images in patients of advanced age with otherwise normal images and in patients who had received brain radiation therapy. We undertook an investigation to determine the frequency of this finding in these patient groups. METHODS: We reviewed the FLAIR images and medical records of 67 patients (group 1) imaged for suspicion of CNS disease and of 18 consecutive patients (group 2) with history of brain radiation therapy. All FLAIR images were evaluated for focal signal intensity abnormalities in the splenium and for diffuse white matter abnormalities. Also, autopsy specimens from two cases not part of either study group were examined. RESULTS: Among the initial 67 patients in group 1, focal high signal intensity in the splenium was associated with aging, radiation therapy, and white matter changes. Focal high signal intensity in the splenium was evident on FLAIR images in 16 of the 18 patients in the post-radiation therapy group. Histologic examination of the splenium in one autopsy case with a history of chest and neck radiation therapy demonstrated isomorphic gliosis. CONCLUSION: High signal intensity in the splenium of the corpus callosum on FLAIR images is a common finding after brain radiation therapy and can be seen with aging. The radiologist should be aware of this common finding and not mistake it for more commonly recognized causes of splenial lesions.     

正常成人脑区水平胼胝体纤维分支概率图谱的构建及连接模式分析

目的 基于扩散谱成像（DSI）技术,利用广义Q空间采样（GQI）重建技术构建正常成人脑区水平的胼胝体纤维分支概率图谱,并研究胼胝体纤维分支在脑区之间的连接模式。 方法 随机选取人类脑连接组计划（HCP）数据库（ https://www.humanconnectome.org）的100名健康成年人的影像资料,男女各50名,平均年龄（25.1±2.3）岁。对DSI数据进行标准化处理后,利用GQI重建技术以胼胝体为种子点进行确定性纤维示踪,基于自动解剖标记图谱（AAL）提取双侧大脑半球间任意2个脑区之间胼胝体纤维束分支,构建脑区水平胼胝体纤维分支概率图谱。采用Bonferroni校正的配对t检验,比较各脑区同源连接及异源连接强度的差异。 结果 构建的胼胝体纤维分支概率图谱（ https://gitee.com/yaojia01/CC）共包括156条胼胝体纤维束分支,主要分布于额、顶、枕叶共50个（25对）脑区中。同源连接18条,异源连接138条;其中双侧的尾状核、前扣带皮质、中扣带皮质、额下回岛盖部、顶下小叶、缘上回只有异源连接。50个脑区中有48个脑区的同源连接少于异源连接（P<0.05,Bonferroni校正）,另外2个脑区中,右侧直回脑区的同源连接多于异源连接（P<0.05,Bonferroni校正）,而右侧旁中央小叶的同源连接和异源连接差异无统计学意义（P>0.05）。 结论 根据构建的正常成人脑区水平胼胝体纤维分支概率图谱发现各脑区的胼胝体纤维连接以异源连接为主。     

Sinogram affirmed iterative reconstruction in head CT: Improvement of objective and subjective image quality with concomitant radiation dose reduction

Purpose

Iterative reconstruction has recently been revisited as a promising concept for substantial CT dose reduction. The purpose of this study was to assess the potential benefit of sinogram affirmed iterative reconstruction (SAFIRE) in head CT by comparing objective and subjective image quality at reduced tube current with standard dose filtered back projection (FBP).

Materials and methods

Non-contrast reduced dose head CT (255 mA s, CTDI_vol 47.8 mGy) was performed in thirty consecutive patients and reconstructed with SAFIRE and FBP. Images were assessed in terms of quantitative and qualitative image quality and compared with FBP of standard dose acquisitions (320 mA s, CTDI_vol 59.7 mGy).

Results

In reduced dose CT examinations, use of SAFIRE versus FBP resulted in 47% increase in contrast-to-noise ratio (CNR) (2.49 vs. 1.69; p < 0.0001). While reduction of tube current was associated with 13% decrease in CNR, quantitative degradation of image quality at lower dose was more than compensated through SAFIRE (2.49 vs. 1.96; p = 0.0004). Objective measurements of image sharpness were comparable between FBP and SAFIRE reconstructions (575.9 ± 74.1 vs. 583.4 ± 74.7 change in HU/Pixel; p = 0.28). Compared to standard dose FBP, subjective grading of noise as well as overall image quality scores were significantly improved when SAFIRE was used in reduced dose exams (1.3 vs. 1.6, p = 0.006; 1.3 vs. 1.7, p = 0.026).

Conclusion

At 20% dose reduction, reconstruction of head CT by SAFIRE provides above standard objective and subjective image quality, suggesting potential for more vigorous dose savings in neuroradiology CT applications.     

静脉尿路造影术与MR水成像技术在泌尿系统疾病检查中的对比分析

目的:评价静脉尿路造影技术(IVU)与低场强磁共振泌尿系水成像技术(MRU)在泌尿系统疾病检查 中的应用价值。方法:对20例(正常5例,输尿管结石8例,输尿管移行细胞癌1例,输尿管中下段狭窄、扭曲2例, 肾囊肿2例,肾透明细胞癌2例)泌尿系统疾病患者,均行IVU与MRU检查,并进行对比分析。结果:IVU和 MRU检查均能清晰显示输尿管的梗阻部位,定位正确率100%,而定性正确率MRU高于IVU,且对输尿管梗阻的 病变显示较佳,但MRU不能直接观察肾脏的分泌功能。结论:泌尿系统疾病患者应首选IVU检查,以观察其功能 和形态,而对输尿管有梗阻或肾脏有占位性病变的患者应选用MRU,对儿童及不能耐受IVU检查的患者MRU也 可作为首选。     

Measurements of diagnostic examination performance and correlation analysis using microvascular leakage,cerebral blood volume,and blood flow derived from 3T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in glial tumor grading

Introduction  

To assess the diagnostic accuracy of microvascular leakage (MVL), cerebral blood volume (CBV) and blood flow (CBF) values derived from dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MR imaging) for grading of cerebral glial tumors, and to estimate the correlation between vascular permeability/perfusion parameters and tumor grades.     

腰椎轴向负荷的CT、MR检查对腰椎退行性病变的诊断价值

目的：评价腰椎轴向负荷的CT、MR检查对腰椎退行性病变的诊断价值。方法：对100例腰腿痛的患者（79例表现为坐骨神经痛，20例为下腰痛，1例为神经性跛行）分别行腰大肌放松体位（PRP）和腰椎轴向负荷仰卧位（ACE）的CT或MR检查。其中CT检查40例，MR检查60例。硬膜囊面积在ACE检查中较PRP明显减小（〉15mm^2）并降到75mm^2以下、侧隐窝和（或）椎间孔狭窄、椎间盘突出程度增加及出现滑膜囊肿为腰椎轴向负荷检查的附加信息（AVI）。结果：40例CT检查的患者中，16例发现AVI。其中硬膜囊面积减小13例，椎间盘突出程度增加7例，侧隐窝和（或）椎间孔狭窄4例，未见滑膜囊肿的病例。60例MR检查的患者中，19例发现AVI，其中硬膜囊面积减小13例，椎间盘突出程度增加10例，侧隐窝和（或）椎间孔狭窄8例，未见出现滑膜囊肿的病例。79例坐骨神经痛的患者中32例（40．5％）出现AVI，20例下腰痛的患者中2例（10．0％）出现AVI（X2=7．45，P〈0．05）。结论：与常规腰椎CT、MR方法比较，腰椎轴向负荷的CT、MR检查更能反映腰椎直立状态下的椎间盘、硬膜囊、侧隐窝的状态。