对比增强磁化传递MRI在肺癌脑内小转移灶成像中的价值

目的　探讨对比增强磁化传递 (magnetisationtransfer,MT)MRI在肺癌脑内小转移灶的应用。方法　对 6 0例病人 (含 172个转移灶 )进行对比增强磁化传递前后的对照研究。对比增强磁化传递前采用SE序列T1WI。然后 ,注射钆喷替酸葡甲胺 (Gd DTPA) (0 1mmol/kg)增强后 ,进行SE序列T1WI和SE序列T1WIMT技术成像。通过比较对比度 /噪声比值 (C/Ns值 ) ,对采用MT技术与否的影像结果进行评估 ;再对采用MT技术与否所显示的转移灶数量进行对照。结果　所有采用T1WI对比增强MT技术的图像C/Ns值比常规T1WI对比增强图像的C/Ns值高。采用MT技术图像的C/Ns值为 2 6 98± 7 0 6 ( x±s) ,常规T1WI对比增强图像的C/Ns值为 15 5 1± 8 5 4 ,t =8 0 2 ,P <0 0 1。T1WI对比增强MT技术比常规T1WI对比增强能显示更多的转移灶数目 (6 0个 ) ,χ2 =7 79,P <0 0 1。结论　在显示肺癌脑内小转移灶方面 ,T1WIMT对比增强比常规T1WI对比增强更为敏感 ,对评估中枢神经系统转移性疾病具有重要的临床价值。     

Contrast-enhanced magnetisation transfer MRI in metastatic lesions of the brain

Our purpose was to compare prospectively the sensitivity of contrast-enhanced magnetisation transfer (MT) MRI and gradient-echo (GE) T1-weighted images in metastatic disease of the brain. We studied 52 patients with brain metastases, using conventional T1-weighted GE and MT spin-echo (SE) images after the same standard dose of gadolinium. Axial 5-mm reconstructions of GE data were compared with 5-mm MT images in the same plane. Metastases were counted independently by two neuroradiologists. In 12 patients (23 %) MT imaging showed more metastases than GE images (P = 0.03). We detected 68 more metastases with the former technique. Received: 27 July 1997 Accepted: 22 April 1998     

Tissue characterisation of intracranial tumours: the value of magnetisation transfer and conventional MRI

We performed MRI on 85 patients with intracranial tumours to evaluate quantitative analysis in tumour characterisation. Signal intensities were measured on standard T2-and T1-weighted images, Gd-enhanced T1-weighted images and magnetisation transfer (MT) images. Statistically significant differences between tumour types were observed, but overlapping reduces their value. T2-weighted imaging was superior to T1-weighted imaging for tumour characterisation. Quantification of Gd enhancement was useful in the diagnosis of pituitary adenomas and haemangioblastomas, but of minor importance in other tumours, because of large nonspecific variation. The contribution of MT contrast to tumour characterisation resembled that of T2 contrast. However, MT imaging was superior to other sequences in the classification of intra-axial tumours. Low-grade astrocytomas, haemangioblastomas and craniopharyngiomas could be differentiated from other tumours on the basis of MT contrast. Reliable discrimination between meningiomas, high-grade astrocytomas and metastases was not possible by any of the methods.     

Diffusion- and magnetisation transfer-weighted MRI in childhood moya-moya

Abstract MRI in two children with moya-moya demonstrated low signal on T2-weighted images in the acute and subacute phases of ischaemia. Gradient-echo sequences, more sensitive to magnetic susceptibility, demonstrated these abnormalities better. Signal loss, due to temporary accumulation of iron, decreases progressively and disappears in the chronic stage of the disease. Diffusion-weighted MRI allows early detection of ischaemic lesions and can be used to monitor progressive spreading of the lesions. Magnetisation transfer maps provide sharp contrast, useful for demonstrating cortical atrophy. Received: 14 August 1997 Accepted: 22 September 1997     

Use of magnetisation transfer contrast to improve cerebral 3D MR angiography

To improve 3D-time of flight (3D-TOF) magnetic resonance angiography, we used magnetisation transfer (MT) to increase the contrast between flowing blood and stationary tissues. With a 1.5 KHz off-resonance radio-frequency MT applied for 16 ms at a maximum power within specific absorption rate (SAR) limits, a 37% decrease in the signal of white matter was obtained, whereas the signal from flowing blood decreased by only 8%. An improvement in maximum intensity projection (MIP) image quality was obtained all MT-3DTOF studies on seven volunteers using progressively more powerful MT pulses. Routine clinical use of MT-3DTOF appears promising and can be achieved at any strength field.     

Magnetisation transfer imaging of the normal adenohypophysis: the effect of sex and age

Magnetisation transfer (MT) techniques provide tissue contrast depending mainly on the concentration of macromolecules. Because many macromolecules are involved in the secretory activity of the pituitary gland, MT techniques might be useful in the study of pituitary gland disorders. Our purpose was to establish a quantitative database of the MT ratio (MTR) of the normal adenohypophysis and to see whether there are age- and sex-related differences. Using a three-dimensional gradient-echo sequence for MT we studied the adenohypophysis in 56 males and 61 females aged 7 months-77 years; postsaturation images were obtained using an on-resonance binomial prepulse. The images were normal in all but three patients, two with meningiomas, one with a schwannoma). Adenohypophyseal MTR increased in both sexes up to 19 years of age (r = 0.47 males, 0.39 females, P < 0.05 ). In men after 20 years and in women from 20–49 years MTR decreased (r = –0.68, P < 0.001, r = –0.46, P < 0.05, respectively). In women aged 50–59 years the MTR again increased slightly. The MTR in males was slightly higher at all ages except before 9 and after 50 years of age. These differences were not statistically significant except in the 40–49 year group (P < 0.05). Received: 11 August 2000 Accepted: 8 September 2000     

Magnetisation transfer ratios of contrast-enhancing and nonenhancing lesions in multiple sclerosis

Magnetisation transfer (MT) is a recently introduced technique for assessing the water content of tissues in vivo and its relationship to macromolecules or membranes. It has been suggested that MT could provide indirect evidence of the characteristics of multiple sclerosis (MS) lesions (oedema, demyelination, or gliosis). Our aims were to characterise brain MS lesions and to compare the magnetisation transfer ratio (MTR) values of lesions with different patterns of contrast enhancement. In patients with MS we measured the MTR of 65 gadolinium-enhancing and 292 nonenhancing lesions. Using the equation published by Dousset et al. we studied 29 patients with clinically definite MS and 10 healthy controls. Lesions had significantly lower MT than the normal-appearing white matter of the patients or the normal white matter of healthy controls. There was no difference in the MTR of enhancing and nonenhancing lesions. Enhancement was homogeneous in 45 and ring-like in 20 lesions; MTR values were lower in the latter. These findings are presumably related to the differences in pathological features of enhancing (different amounts of proteins and inflammatory cells, oedema and demyelination) and nonenhancing (gliosis, demyelination and axonal loss) lesions.     

高压氧综合治疗对非动脉炎性前部缺血性视神经病变患者的临床疗效

目的:探讨高压氧综合治疗非动脉炎性前部缺血性视神经病变(non-arteritic anterior ischemic optic neuropathy,NAION)患者的临床疗效。方法:选取2017年1月至2019年1月郑州市第二人民医院收治的NAION患者110例,采用随机数字表法将患者分为对照组(55例)和高压氧...     

The effect of magnetisation transfer contrast on cerebrospinal fluid on motion artefacts on fluid-attenuated inversion-recovery images

We assessed possible advantages of the use of fluid-attenuated inversion-recovery (FLAIR) sequences with magnetisation-transfer contrast (MTC) over conventional FLAIR images. We carried out cranial MRI at 1 tesla on 50 patients with both sequences. In nine patients with multiple sclerosis (MS) we performed a quantitative comparison of the two sequences, looking at the contrast-to-noise ratio between lesions and normal white matter and counting the number of lesions shown using each method. A qualitative comparison on all patients consisted of the analysis of the appearance of the normal parenchyma, of any lesions, and of artefacts, with particular reference to cerebrospinal fluid (CSF) motion artefacts. The quantitative analysis showed no meaningful difference between the two sequences. The cerebral parenchyma and lesions appeared substantially the same with both techniques. With FLAIR MTC there was a clear, and consistent reduction in CSF motion artefacts. FLAIR MTC sequences can usefully be used in place of the conventional sequence at 1 tesla.     

Potential for increasing conspicuity of short-T1 lesions in the brain using magnetisation transfer imaging

We investigated the feasibility of using T1-weighted magnetisation transfer sequences to generate tissue contrast and increase the conspicuity of short-T1 areas within the brain. We imaged two normal volunteers with and without saturating off-resonance radiofrequency irradiation at a range of repetition times (TR 200–760 ms). T1 values and magnetisation transfer ratios for white matter and deep grey matter were calculated. We studied eight patients with intracranial lesions showing short-T1 areas, using mildly T1-weighted sequences with and without magnetisation transfer contrast. Lesion numbers, areas and signal intensities were measured and lesion-to-background contrast was calculated. Comparison was made with conventional T1-weighted spin-echo images. In the normal volunteers, contrast between the thalamus, caudate and lentiform nuclei and white matter showed striking visual differences, with magnetisation transfer weighting, with decreasing TR. In all patients, short-T1 lesions were seen more clearly on magnetisation transfer-weighted images, with significant increase in lesion number, area and contrast, when compared with conventional T1-weighted scans.     

Degenerative diseases of the cervical spine: comparison of a multiecho data image combination sequence with a magnetisation transfer saturation pulse and cervical myelography and CT

Assessing degenerative disease in the cervical spine remains a challenge. There is much controversy about imaging the cervical spine using MRI. Our aim in this prospective study was to compare a T2*-weighted 2D spoiled gradient-echo multiecho sequence (MEDIC) with a magnetisation transfer saturation pulse with cervical myelography and postmyelographic CT. Using an assessment scale we looked at the vertebral bodies, intervertebral discs, neural foramina, anterior and posterior nerve roots, grey matter, ligamenta flava, oedema in the spinal cord and stenosis of the spinal canal. We also evaluated postmyelography CT and the MEDIC sequence for assessing narrowing of the neural foramina in a cadaver cervical spine. We examined 67 disc levels in 18 patients, showing 18 disc prolapses and 21 osteophytes narrowing the spinal canal or the neural foramina. All MRI studies showed these abnormalities findings equally well. Postmyelography CT was significantly better for showing the bony structures and the anterior and posterior nerve roots. The MEDIC sequence provided excellent demonstration of soft-tissue structures such as the intervertebral disc and ligamentum flavum. No statistical differences between the imaging modalities were found in the assessment of narrowing of the neural foramina or the extent of spinal stenosis. The cadaver measurements showed no overestimation of abnormalities using the MEDIC sequence.     

MRI of the anterior optic pathways following enucleation

We examined five patients who had enucleation of one eye for inflammatory or neoplastic disease, using MRI at 1.5 Tesla. None had symptoms referable to the enucleated orbit. In addition, age- and-sex matched individuals were imaged as control subjects, and a further 15 subjects, referred for other than orbital disease, were reviewed. Measurements were made retrospectively of the dimensions of the optic chiasm to establish normal values. All five patients showed abnormalities on MRI following enucleation: abnormal signal within the optic nerve remnant on short τ inversion recovery (STIR) images, and atrophy of the nerve remnant and the chiasm. These findings were not apparent in the control or normal subjects. Such findings are to be expected following enucleation and should not be interpreted as indicating active pathology. Received: 17 June 1996 Accepted: 7 March 1997     

原发性青光眼患者双侧视放射及视皮质的磁化传递成像

目的 应用磁化传递成像(MTI)研究原发性青光眼患者双侧视放射、视皮质的异常,探讨青光眼性损伤对后视路的影响.方法 选取20例常规颅脑MR检查无异常的原发性青光眼患者(青光眼组)及31名正常志愿者(对照组)行MTI检查,采用扰相梯度回波序列(SPGR)成像,分别于施加磁化传递饱和脉冲前后进行扫描.将扫描图像进行后处理分析,测量双侧视放射及视皮质的磁化传递率(MTR).组间各部位MTR值的比较采用两样本t检验(方差不齐则采用Satterthwaite近似t检验).结果 青光眼组左、右两侧视放射的MTR值分别为(32.8±2.2)％、(32.7±2.0)％,对照组相应部位MTR值分别为(34.6±1.4)％、(34.8±1.3)％,青光眼组低于对照组,差异有统计学意义(左侧t=3.284,右侧t=4.040;P值均＜0.01).青光眼组左、右两侧视皮质的MTR值分别为(30.1±2.0)％、(30.8±1.8)％,对照组相应部位MTR值分别为(32.3±1.2)％、(32.4±1.2)％,青光眼组低于对照组,差异也有统计学意义(左侧t =4.319,右侧t=3.445;P值均＜0.01).结论 青光眼患者后视路发生了潜在神经病理学变化,提示青光眼是累及全视路的病变.MTI能在肉眼可见的影像学改变之前提供微观病理方面的信息,是活体人青光眼视觉通路跨突触损害研究的有用方法,也为青光眼临床诊治及评估预后提供了新的思路.     

Diagnostic use of isotropic diffusion-weighted MRI in patients with ischaemic stroke: detection of the lesion responsible for the clinical deficit

We examined the diagnostic use of isotropic diffusion-weighted (DW) MRI in 140 consecutive patients suspected of or diagnosed as having an ischaemic stroke. Isotropic DW imaging could demonstrate the lesion responsible for the clinical deficit in patients with multiple cerebral infarts at an early stage, even small lesions without a perifocal oedema or mass effect. Accurate diagnosis by DW images may, however, be difficult about 2 weeks after the onset of stroke. Received: 15 November 1998 Accepted: 12 February 1999     

MRI of the intraorbital optic nerve in patients with autosomal dominant optic atrophy

Measurements of the intraorbital optic nerve were made using high-resolution coronal MRI in 10 adults with autosomal dominant optic atrophy. Comparisons were made with previous studies of 10 normal adult subjects. The cross-sectional diameters of the optic nerve and the perineural subarachnoid space were measured and a ratio of there diameters at anterior, mid and posterior positions along the optic nerve was determined. We found a statistically significant difference in the mean optic nerve: sheath ratio between the control group and patients with autosomal dominant optic atrophy. At anterior, mid and posterior locations along the optic nerve it is significantly smaller in patients with optic atrophy. We have demonstrated that the loss of ganglion cells, previously documented in dominant optic atrophy, is associated with a significant loss of optic nerve tissue and thinning of the nerve along its length. Received: 6 July 1999/Accepted: 22 July 1999     

视交叉病变的MRI分析

目的 分析视交叉病变的MRI表现，探讨MRI对视交叉病变的诊断价值。方法 回顾性分析经临床或病理证实的117例视交叉病变的MRI表现。男54例，女63例，年龄9个月至67岁，平均37．4岁。117例均行MR扫描，101例同时行增强扫描。结果 直接累及视交叉的病变24例，占20．5％。其中胶质瘤11例，表现为视交叉增粗或肿块，伴有视神经或(和)视束受累；炎性病变5例，表现为视交叉弥漫性增粗伴周围结构异常强化，特别是脑膜的炎症；转移瘤5例，其中4例表现为球内肿块沿视神经向球后及颅内侵犯累及视交叉，1例表现为视交叉边缘线状强化伴广泛脑膜强化；脑膜瘤1例，表现为视交叉局限性强化伴视神经肿块；外伤1例，表现为视交叉形态异常伴额叶软化灶；出血1例，表现为视交叉不规则增粗，呈短T1、长T2信号。引起视交叉移位的病变93例，占79．5％，其中视交叉向上移位51例，向前移位2例，向下移位10例，向后移位1例。视交叉一侧受压13例，视交叉显示不清16例。结论 MRI能清晰地显示视交叉病变的特点，对临床诊断与治疗有重要价值。     

高压氧联合银杏达莫治疗前部缺血性视神经病变的疗效观察

目的 观察高压氧联合银杏达莫治疗前部缺血性视神经病变的疗效.方法 单眼前部缺血性视神经病变患者76例,经患者知情同意,并签署知情同意书后分为高压氧治疗组38例和对照组38例,在常规治疗的同时,高压氧治疗组给予高压氧联合银杏达莫治疗,对照组给予银杏达莫治疗,治疗周期30 d,以视力、视野改变为疗效判断指标进行观察分析.结果 治疗组总有效率92.1％,对照组73.7％,2组差异有统计学意义(P＜0.05).结论 高压氧联合银杏达莫治疗前部缺血性视神经病变具有较好的疗效.     

MRI techniques and cognitive impairment in the early phase of relapsing-remitting multiple sclerosis

Correlation studies between various conventional and non-conventional MRI parameters and cognitive impairment in the early stages of multiple sclerosis (MS) are lacking, although it is known that a number of patients with early MS have mild cognitive impairment. Our aim was to explore whether this cognitive impairment is dependent on the extent and severity of the burden of disease, diffuse microscopic brain damage or both. We studied 63 patients with clinically definite relapsing-remitting (RR) MS, duration of disease 1–10 years and Expanded disability status scale scores ≤ 5.0. Mean age was 35.4 years, mean duration of disease 5.8 years and median EDSS score 1.5. Neuropsychological performance, psychological function, neurological impairment and disability were assessed. The patients also underwent MRI, including magnetisation-transfer (MT) studies. We quantified the lesion load on T2- and T1-weighted images, the magnetisation transfer ratio (MTR) of normal-appearing brain tissue (NABT) and the brain parenchymal fraction (BPF). No significant difference was found between lesion loads in patients with and without cognitive impairment. In 15 patients (23.8 %) with overall cognitive impairment, median BPF and average NABT MTR were significantly lower than those in patients without cognitive impairment (0.868 vs 0.892, P = 0.02 and 28.3 vs 29.7 P = 0.046, respectively). Multiple regression analysis models demonstrated that the only variables independently correlated with cognitive impairment were: BPF (R = 0.89, P = 0.001) and average NABT MTR (R = 0.76, P = 0.012). Our findings support the hypothesis that, cognitive decline in patients with MS, a low disability score and short duration of disease is directly associated with the extent and severity of diffuse brain damage. The loss of brain parenchyma did not correlate with the severity of microscopic damage in the NABT, indicating that the two processes could be distinct in the early stages of the disease. Received: 7 August 2000 Accepted: 18 October 2000     

MR spectroscopy (MRS) and magnetisation transfer imaging (MTI), lesion load and clinical scores in early relapsing remitting multiple sclerosis: a combined cross-sectional and longitudinal study

The purpose of this study was to correlate magnetic resonance imaging (MRI)-based lesion load assessment with clinical disability in early relapsing remitting multiple sclerosis (RRMS). Seventeen untreated patients (ten women, seven men; mean age 33.0 ± 7.9 years) with the initial diagnosis of RRMS were included for cross-sectional as well as longitudinal (24 months) clinical and MRI-based assessment in comparison with age-matched healthy controls. Conventional MR sequences, MR spectroscopy (MRS) and magnetisation transfer imaging (MTI) were performed at 1.5 T. Lesion number and volume, MRS and MTI measurements for lesions and normal appearing white matter (NAWM) were correlated to clinical scores [Expanded Disability Status Scale (EDSS), Multiple Sclerosis Functional Composite (MSFC)] for monitoring disease course after treatment initiation (interferon β-1a). MTI and MRS detected changes [magnetisation transfer ratio (MTR), N-acetylaspartate (NAA)/creatine ratio] in NAWM over time. EDSS and lesional MTR increases correlated throughout the disease course. Average MTR of NAWM raised during the study (p < 0.05) and correlated to the MSFC score (r = 0.476, p < 0.001). At study termination, NAA/creatine ratio of NAWM correlated to the MSFC score (p < 0.05). MTI and MRS were useful for initial disease assessment in NAWM. MTI and MRS correlated with clinical scores, indicating potential for monitoring the disease course and gaining new insights into treatment-related effects. J. Bellmann-Strobl, H. Stiepani and J. Wuerfel contributed equally to this work.     

中国汉族正常成人视束的高分辨率MRI测量

目的 研究中国汉族正常成人视束MRI形态特征,为建立中国标准脑提供视束形态学测量数据.方法 采用全国多中心临床研究形式,选取18～70岁健康中国成年志愿者共1000名,按照年龄18～30、31～40、41～50、51～60、61～70岁分为A、B、C、D、E组,每组男、女各100例.所有受试者均行3D磁化强度预备梯度回波序列T1WI采集容积数据,再采用多基线技术最佳化显示视束结构及形态,测量视束各径线:视束脑池段横径(TD1)、视束大脑脚周段横径(TD2)、视束起点池段到大脑脚周段长度(L)、视束夹角(AOT),以及视束从前到后5个断面上下径(H):视束起始点层面上下径(H1)、视束池-前联合层面上下径(H2)、视束乳头体层面上下径(H3)、视束室间孔层面上下径(H4)、视束近外侧膝状体节段上下径(H5).不同性别及年龄分组的视束测量值比较采用协方差分析,左、右视束侧别的比较采用配对样本t检验分析.结果 (1)男、女性别间视束径线比较:男性左、右侧L分别为(11.69±1.45)、(11.56±1.44)mm,女性左、右侧L分别为(10.58±1.29)、(10.40±1.34)mm,男性左、右侧H1分别为(2.56±0.28)、(2.60±0.29)mm,女性左、右侧H1分别为(2.57±0.31)、(2.63±0.32)mm,以上测量指标在性别间差异有统计学意义(F值分别为22.236、29.703、11.130、7.805,P值分别为0.000、0.000、0.000、0.005),男性L大于女性,男性H1小于女性;余测量径线性别差异无统计学意义(P值均>0.05);(2)年龄分组比较:左、右侧TD1、右侧TD2在5个年龄分组的值分别为:左TD1为(4.64±0.51)、(4.64±0.57)、(4.55±0.58)、(4.39±0.53)、(4.36±0.58)mm;右TD1为(4.84±0.53)、(4.80±0.60)、(4.77±0.65)、(4.60±0.59)、(4.57±0.59)mm;右TD2为(3.33±0.45)、(3.34±0.41)、(3.33±0.36)、(3.23±0.38)、(3.23±0.39)mm,在年龄分组间差异有统计学意义(F值分别为3.458、2.735、4.711,P值分别为0.008、0.028、0.001),且两两比较结果为50岁前后差异有统计学意义(P值均<0.05);左、右侧L在5个年龄分组的值分别为:左L为(11.09±1.37)、(10.99±1.58)、(10.96±1.43)、(11.15±1.53)、(11.50±1.40)mm;右L为(10.88±1.35)、(10.79±1.62)、(10.83±1.45)、(11.04±1.52)、(11.34±1.51)mm,在年龄分组间差异有统计学意义(F值分别为14.510、14.532,P值均为0.000),两两比较结果为60岁前后差异有统计学意义(P值均<0.05);左TD2及双侧H1～H5年龄分组差异无统计学意义(P值均>0.05);(3)视束测量径线的左、右侧别比较:左、右侧TD1分别为(4.52±0.57)、(4.72±0.60)mm,左、右侧H1分别为(2.56±0.30)、(2.61±0.30)mm,左、右侧H2分别为(2.66±0.30)、(2.70±0.30)mm,左、右侧L分别为(11.14±1.47)、(10.98±1.50)mm,以上测量指标侧别差异均有统计学意义(t值分别为12.460、-6.013、5.595、4.784,P值均为0.000),双侧TD2、H3、H4及H5侧别差异无统计学意义(P值均>0.05).结论 高分辨率MRI 3D数据重组能清晰显示视束形态,能准确测量视束各段径线.