Magnetic resonance imaging of the muscles in patients with polymyositis and dermatomyositis

Magnetic resonance imaging (MRI) of the muscles was performed in patients with polymyositis and dermatomyositis. Lesions with high intensity on T2-weighted image, but normal intensity on T1-weighted image, were observed in 7 of 8 patients in the active stage of the disease. Following clinical improvement with corticosteroid therapy in 4 patients, the high intensity lesions reverted to normal. The high intensity lesions seen on T2-weighted image in the active stage may represent edema and inflammation of the muscle. MRI of the muscle may serve as a diagnostic tool and be useful for follow-up of the patients with polymyositis or dermatomyositis.     

磁共振成像在多发性肌炎、皮肌炎诊断中的应用

目的 研究多发性肌炎(PM)、皮肌炎(DM)的磁共振成像(MRI)表现，评价MRI在PM及DM诊断中应用价值。方法 对5例PM及4例DM患者行MRI检查，选择骨盆、双侧大腿及小腿肌肉，采用自旋回波序列(SE)、快速自旋回波序列(FSE)及短时反转恢复序列(STIR)进行扫描。结果 5例PM及4例DM患者的受累肌群均表现为斑片状等T1长T2异常信号，2例PM患者尚可见小斑片状短T1长T2异常信号影；6例患者肌筋膜增厚，呈长T2线样高信号改变；4例DM患者的表皮及皮下结缔组织尚可见条带状及网格状长T1长T2异常信号影。受累肌群主要表现为炎症水肿样改变，晚期受累肌肉可见少量脂肪替代改变；病变双侧不对称，以内收肌受累最重，股中间肌受累最轻。结论 PM与DM患者的MRI表现具有一定的特征性，MRI能为PM及DM的定位诊断、疗效判断及病情随访提供客观资料，并能为临床选取准确的活检部位提供帮助。     

Magnetic resonance imaging of skeletal muscles in idiopathic inflammatory myopathies of adults

The purpose of the study was to describe typical MRI findings in various types of idiopathic inflammatory myopathies in adulthood and to correlate the MRI with histopathological and electromyographic findings, and the serum creatine kinase (CK) activity. A third goal was to assess the diagnostic value of the use of gadolinium-DTPA (Gd-DTPA). Fifty-eight patients (35 women, 23 men), aged 21–83 years (median age 59 years), suffering from idiopathic myositides (13 with acute and 45 chronic diseases; 25 with polymyositis, 14 with dermatomyositis, 8 with granulomatous and 11 with inclusion body myositides) were examined with MRI. Seventeen of them received an intravenous infusion of Gd-DTPA. Histopathological and MRI findings of 21 muscles of 18 patients were compared. MRI of skeletal muscles showed abnormal signal intensities in 56 (96.6%) of the 58 patients. MRI abnormalities were found more often than elevated CK activity (P < 0.001). The hyperintensity of T2-weighted images was more conspicuous than on T1-weighted images in 26 (44.8%) patients, indicating oedema-like abnormalities. MRI of 50 (86.2%) patients showed fat replacement. In acute myositides, oedema-like abnormalities were more often visible and in muscle lipomatosis less often visible than in chronic diseases (P < 0.05 each). In dermatomyositis oedema-like abnormalities were more and lipomatosis less frequent than in the other types of myositis (P < 0.005) and correlated with the acuteness of the disease. In 3 of 17 patients in whom contrast-enhanced T1-weighted images were obtained in addition to plain T1- and T2-weighted images, T2-weighted images were more sensitive in the detection of oedema-like abnormalities than the contrast-enhanced T1-weighted images. In no patient was the opposite true. Thus, contrast-enhanced T1-weighted images did not provide more information than T2-weighted images. Nine patients with poly-, dermato- and inclusion body myositis showed clearly asymmetrical findings. Imaging of the thighs and legs was of similar sensitivity. The different types of myositides showed typical but not specific distributions of the mesenchymal abnormalities in MRI. The findings indicate that MRI of skeletal muscles in myositides can visualize the presence and distribution of oedema-like abnormalities and intramuscular lipomatosis and is suitable for the assessment of the chronicity and severity of the disease.     

Magnetic resonance imaging in clinical psychiatry

Although psychiatric researchers have been quick to adopt magnetic resonance imaging (MRI) of the brain in their investigations, its clinical application has been slow to develop and most psychiatrists remain unaware of its potential advantages and disadvantages compared with CT scanning. In this article the procedures are compared and the potential advantages of MRI highlighted with the help of neuropsychiatric case histories. Clinical situations are then discussed in which a psychiatrist should consider ordering a MRI scan subsequent to or instead of a CT scan.     

Magnetic resonance imaging markers for early diagnosis of Parkinson’s disease

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by selective and progressive degeneration, as well as loss of dopaminergic neurons in the substantia nigra. In PD, approximately 60-70% of nigrostriatal neurons are degenerated and 80% of content of the striatal dopamine is reduced before the diagnosis can be established according to widely accepted clinical diagnostic criteria. This condition describes a stage of disease called "prodromal", where non-motor symptoms, such as olfactory dysfunction, constipation, rapid eye movement behaviour disorder, depression, precede motor sign of PD. Detection of prodromal phase of PD is becoming an important goal for determining the prognosis and choosing a suitable treatment strategy. In this review, we present some non-invasive instrumental approaches that could be useful to identify patients in the prodromal phase of PD or in an early clinical phase, when the first motor symptoms begin to be apparent. Conventional magnetic resonance imaging (MRI) and advanced MRI techniques, such as magnetic resonance spectroscopy imaging, diffusion-weighted and diffusion tensor imaging and functional MRI, are useful to differentiate early PD with initial motor symptoms from atypical parkinsonian disorders, thus, making easier early diagnosis. Functional MRI and diffusion tensor imaging techniques can show abnormalities in the olfactory system in prodromal PD.     

急性期脑梗死的磁共振化学位移成像研究

目的采用磁共振化学位移成像(CSI)研究急性期脑梗死不同部位代谢产物浓度变化 的差异及其与弥散加权成像(DWI)表现的相关性。方法28例发病3d内非腔隙性脑梗死患者完成 CSI和DWI检查。测算梗死区N-乙酰天门冬氨酸(NAA),肌酸(Cr),胆碱化合物(Cho)与对侧相应 正常脑区代谢产物比值(rNAA、rCr、rCho)及同侧乳酸／胆碱值(Lac／Cho),比较不同部位各代谢产物 相对浓度;比较:DWI上梗死区相对信号强度(rDWI)、表观弥散系数(rADC)值与代谢产物浓度的相 关性。结果(1)与对应脑区比较,急性期脑梗死灶内NAA明显降低,Lac明显增加(P<0.001),cr、Cho无显著变化(P=0.543,0.817)。(2)梗死核心区、内缘、外缘及正常组织间rNAA及Lac／Cho差异均有显著意义(均P<0.001),rCr及rCho各部位间差异无显著意义(P=0.266,0.737)。rNAA梗死外缘与正常区域间差异无显著意义(P=0.733);Lac／Cho外缘与正常区域差异有显著意义(P=0.003)。(3)急性期脑梗死rNAA与Lac／Cho(r=0.496)、rADC(r=0.405)成正相关,与rDWI成负相关(r=-0.432);Lac／Cho与rDWI成负相关(r=-0.587),与rADC成正相关(r=0.561)。结论(1)急性期梗死灶NAA降低局限于DWI高信号范围内,而Lac升高范围可超过NAA下降和DWI高信号区域,可能预示缺血半影区。(2)急性期梗死区La     

Magnetic resonance imaging of the brain in patients with acute monosymptomatic optic neuritis

Ophthalmologists and neurologists from a catchment area of 1.5 million people were asked to refer all patients with symptoms and signs of optic neuritis (ON) to our neurological department immediately. A total of 68 consecutive patients were extensively screened for known etiologies of ON. Eleven had definite multiple sclerosis (MS); 7 patients could not participate for various reasons. The cerebrum, cerebellum and brainstem of the remaining 50 untreated patients with monosymptomatic ON were MRI scanned at 1.5 T with 2 sequences (slice thickness 4 mm, voxel size 1.2 x 1.2 x 4 mm3): double spin-echo (TR = 1.8 s, TE = 30 and 90 ms, 12 slices axially) and inversion recovery (TR = 2.45 s, TI = 400 ms, TE = 30 ms, 5 slices sagittaly). Magnetic resonance imaging (MRI) was performed within 3-49 (median 16) days from onset of symptoms. MRI demonstrated multiple asymptomatic central nervous system (CNS) lesions in 62% of patients. The appearance, locations and extents of lesions were consistent with demyelination. A scoring system based on number and size of lesions is proposed. Seven of 50 patients developed definite MS during a median follow-up of 11 months; they all had CNS lesions on the first scan. MRI has thus improved the pathophysiological knowledge of idiopathic ON, which from the very onset is a manifestation of MS in at least two thirds of cases. Patients who have early CNS lesions run a much higher risk of later developing clinically definite MS.     

Magnetic resonance imaging and computed tomography in Alzheimer's disease

Structural neuroimaging with CT and MRI plays an important role in the routine clinical investigation of dementia patients. One major purpouse of the technique is to exclude secondary, treatable dementia disorders. In this respect these techniques are of utmost importance. Another major purpose of these techniques is to differentiate AD from healthy controls and other dementias.
Although some research groups have reported a high sensitivity and specificity for diagnosing AD by measuring the volumes (with MRI) of structures in the temporal lobes, there are no unequivocal "radiological" markers (such as the size of the lateral ventricles or sulci) that can differentiate AD from controls or vascular dementia. There have been a large number of CT and MRI studies showing that the volumes of the temporal lobes or part of the temporal lobes, such as the hippocampal formation are reduced in AD, as compared to healthy subjects.
The role of white matter changes (WMH, leukoaraiosis) in the development of AD or as a diagnostic marker for AD is unclear. The degree of WMH has been shown to be strongly age dependent and there are contradictory data concerning its relation to cognitive decline. There is stronger agreement concerning the relationship between LA assessed with CT and cognitive functions than there is between WMH on MRI and cognitive functions.
Correlative studies with MRI, CT and SPECT or PET are few. Usually the sensitivity and specificity of diagnosing AD can be increased by combining two or more modalities. One other goal with this approach is to use one structural modality, such as MRI or CT as a template for functional images in order to obtain a higher accuracy in measurement of blood perfusion or glucose metabolism.     

Magnetic resonance imaging findings of shoulders in Parkinson's disease

The aim of this study is to evaluate shoulder disturbances in Parkinson's disease (PD) patients using magnetic resonance imaging (MRI) which is the best tool in the demonstration of complex shoulder pathologies; and to determine probable relations between shoulder pathologies and PD clinical features. Twenty‐eight PD patients with a total of 56 shoulders were used as the study group while 13 age‐matched cases with 26 shoulders were used as the control group (CG) in the study. Both patients with PD and the CG underwent shoulder MRI. The Hoehn and Yahr (H&Y) disability scale and Unified Parkinson's Disease Rated Scale (UPDRS) were used to determine the severity of the disease. Our results showed that patients with full‐thickness supraspinatus (SSP) tear have statistically significant higher UPDRS (P = 0.012), tremor (P = 0.023), rigidity (P = 0.023), and total (P = 0.002) scores. Mild group patients (P = 0.045) showed significantly higher frequency resting tremor and subcoracoid effusion than those of severe group patients (P = 0.002). Subcoracoid effusion was observed in patients with significantly higher UPDRS (P = 0.045) and rigidity (P = 0.022) scores. When the resting tremor and subcoracoid effusion groups were compared according to the severity of the resting tremor but not according to the H&Y, higher frequency of full‐thickness tear in SSP tendon was detected in the group of resting tremor (P = 0.053). Longer duration of disease was also observed in patients with full‐thickness SSP tear (P = 0.029) and acromioclavicular joint changes (P = 0.018). Higher UPDRS, tremor, rigidity and total scores and longer PD duration appear as the predisposing factors for the development of shoulder disturbances in PD in this study. © 2010 Movement Disorder Society     

Magnetic resonance imaging and temporal lobe epilepsy

Surgical treatment is a well established option for patients with medically refractory temporal lobe epilepsy. Magnetic resonance imaging (MRI) has revolutionized the evaluation of these patients. New techniques can identify structural, metabolic and functional abnormalities associated with the epileptogenic zone. Mesial temporal sclerosis is the most common pathological finding and presents as hippocampal atrophy, which can be detected by visual inspection in most cases. Volumetric analysis of medial temporal structures offers the advantage of detecting bilateral abnormalities. Magnetic resonance spectroscopy can detect metabolic abnormalities associated with the epileptogenic focus. Functional MRI allows for the non-invasive evaluation of cognitive function, allowing for the localization of the neuroanatomic substrate of motor, sensory and cognitive functions. Intraoperative MRI-based image guided systems are a useful adjunct in the surgical treatment of this epileptic syndrome.     

Magnetic resonance imaging of subacute myelopathy due to cobalamin deficiency

A 77-year-old woman presented with rapidly ascending sensory ataxia. Magnetic resonance imaging (MRI) showed extensive involvement of the dorsal columns of the spinal cord. Hematological data were normal despite severe cobalamin deficiency. The contribution of magnetic resonance imaging in subacute degeneration of the spinal cord is discussed.     

Magnetic resonance imaging of muscle injury and atrophy in glycolytic myopathies

Exertional muscle pain, contractures, recurrent rhabdomyolysis, and pigmenturia are common in certain muscle glycolytic disorders. However, the frequency, distribution, and long-term significance of these findings are poorly understood. First we performed magnetic resonance imaging (MRI) of the extremities as a screening test for the detection of muscle abnormalities incurred in activities of daily living in four patients with myophosphorylase deficiency (MPD) and three with muscle phosphofructokinase deficiency (PFKD). MRI findings of abnormal muscles detected upon screening were next compared with changes observed in a prospective study of muscle contractures involving the forearms of four of the patients (two MPD, two PFKD). Screening revealed abnormalities of proximal thigh muscles in three of seven patients, in two of whom (one MPD, one PFKD) a recent history of exertional myalgia coincided with increases in T1 and T2 estimates of isolated thigh muscles. In the third patient (PFKD), focal atrophy of the adductor magnus was present bilaterally. In prospective studies, focal areas of prolonged T1 and T2 appeared in the flexor digitorum superificalis in all four cases and in the flexor digitorum profundus in two cases. Serial imaging suggested that the onset of MRI abnormalities begins within 24 hours of contracture and persists for at least several days and possibly for much longer, with complete recovery apparently the rule. These cases suggests a high prevalence of focal muscle abnormalities in patients with glycolytic myopathies and show the potential of MRI to detect them.     

Magnetic resonance in the differential diagnosis of dementia

Summary. Magnetic resonance became an important tool for the differential diagnosis of dementia. Magnetic resonance imaging is the preferred method to exclude treatable entities accompagnied by dementing symptoms. New techniques including diffusion and perfusion magnetic resonance imaging are helpful for the differentiation between vascular dementia and degenerative disorders. Magnetic Resonance spectroscopy evolves as a tool for the diagnosis of different forms of degenerative dementia. Multimodal magnetic resonance holds promise to diagnose Alzheimer's disease at early clinical stages and to monitor the progression of the disease. Received July 9, 2001; accepted November 19, 2001     

24例原发性中枢神经系统血管炎患者的MRI表现

目的观察24例原发性中枢神经系统血管炎(PACNS)的磁共振成像(MRI)表现,探讨PACNS的MRI诊断价值。方法对急性期进行了MRI检查的24例经病理证实的PACNS的MRI特点进行了回顾性分析。结果 24例患者中,病灶以幕上多见[19例(79.2%)],最常累及颞叶、额叶、顶叶及基底节区(包括丘脑),分别为13例(54.2%)、10例(41.7%)、8例(33.3%)、8例(33.3%);大部分病灶累及双侧大脑半球[15例(72.5%)],灰质和白质均受累[21例(87.5%)]。MRI上病灶可多发或单发,均为12例(50%)。病灶形态大致可分为四种类型:斑片状、肿块样、脑回状和混合性,分别为12例(50%)、8例(33.3%)、2例(8.3%)和2例(8.3%)。MRI上所有病灶均呈长(稍长)T1WI、长(稍长)T2WI异常信号,增强扫描可见病灶均有强化,FLAIR上均呈高或稍高信号,9例(37.5%)病灶中心呈散点状短T1WI、短T2WI混杂信号。17例行DWI和ADC序列检查者中,9例(52.9%)在DWI上呈高(稍高)信号,ADC上呈等信号或混杂信号影,8例(47.1%)在DWI及ADC上呈等信号。11例行GRE序列检查者,8例(72.7%)可见病灶局部有点状低信号影或病灶周围血管影增粗,余3例未见异常。8例行MRA序列检查者,仅1例发现异常,可见病灶供血区相应血管局部有狭窄。结论本组24例PACNS患者急性期头MRI均有异常,表现多样,病灶以幕上多见,可累及各个脑区,病灶可多发或单发,多数灰白质均受累。其形态可表现为斑片状、肿块样、脑回状或混合性,增强扫描均可见强化,以斑片状或脑回样强化多见。头MRI上病灶多变、灰白质受累、斑片状或脑回样强化等表现对PACNS诊断有一定提示性。     

Magnetic resonance perfusion imaging evaluation in perfusion abnormalities of the cerebellum after supratentorial unilateral hyperacute cerebral infarction

Magnetic resonance imaging (MRI) data of 10 patients with hyperacute cerebral infarction (≤6 hours) were retrospectively analyzed.Six patients exhibited perfusion defects on negative enhancement integral maps,four patients exhibited perfusion differences in pseudo-color on mean time to enhance maps,and three patients exhibited perfusion differences in pseudo-color on time to minimum maps.Dynamic susceptibility contrast-enhanced perfusion weighted imaging revealed a significant increase in region negative enhancement integral in the affected hemisphere of patients with cerebral infarction.The results suggest that dynamic susceptibility contrast-enhanced perfusion weighted imaging can clearly detect perfusion abnormalities in the cerebellum after unilateral hyperacute cerebral infarction.     

脑功能磁共振成像研究进展

主要综述fMRI产生的历史、成像原理、成像技术和方法、已经取得的成绩以及将来研究发展的方向等。fMRI产生技术广泛应用的20世纪90年代,主要受快速成像技术的影响,从有创走向无创,从而受到神经、认知和心理科学领域的极大关注。fMRI原理是根据神经元兴奋后局部氧耗与血流增幅不一致,而BOLD效应机制成像,间接显示神经元活动。成像主要采用平面回波成像（EPI）和快速小角度激发（FLASH）技术、二者在时间和空间分辨率上各有优劣。最后几年来,fMRI技术对脑功能的研究已取得了巨大的成绩,估计将在这一领域继续拥有非常重要的地位。将来fMRI可能主要在BOLD效应的生理过程、临床应用以及高场磁体的应用等领域进一步展开。     

Role of High-Resolution Magnetic Resonance Imaging in the Diagnosis of Primary Angiitis of the Central Nervous System

Background

Primary angiitis of the central nervous system (PACNS) is a rare disorder and is often difficult to diagnose due to the lack of a confirmatory test. PACNS can generally be diagnosed based on typical angiographic findings. We describe herein a patient diagnosed with PACNS despite the presence of normal findings on conventional angiography.

Case Report

A 44-year-old man with a recent history of ischemic stroke in the right posterior cerebral artery territory developed acute-onset vertigo. Diffusion-weighted imaging revealed an acute infarction within the left posterior inferior cerebellar artery. His medical history was unremarkable except for hyperlipidemia; the initial examination revealed mild gait imbalance. During the 10 days of hospital admission, the patient experienced four recurrent ischemic strokes within the posterior circulation territory (occipital lobe, pons, and cerebellum). He was diagnosed with recurrent cerebral infarctions due to PACNS. The basilar artery exhibited no demonstrable luminal stenosis, but there were direct imaging signs of central nervous system angiitis including wall thickening and contrast enhancement. High-dose intravenous steroid therapy followed by oral prednisolone was administered. There was no further stroke recurrence and follow-up imaging of the arterial walls showed normalization of their characteristics.

Conclusions

The present case emphasizes the importance of wall imaging in the diagnosis and treatment of PACNS.     

Post-cranioplasty cerebrospinal fluid hydrodynamic changes: Magnetic resonance imaging quantitative analysis

Abstract

The syndrome ofthe trephined has been described in many patients with cranial defects as an indication for cranioplasty. Cerebral blood flow changes, the effect of the atmospheric pressure on the brain, as well as cerebrospinal fluid hydrodynamic changes have been postulated as the possible reasons for this syndrome. Using dynamic phase-contrast magnetic resonance imaging -we measured arteria II venous, and cerebrospinal fluid flow into and out of the skull, before and after cranioplasty in one patient whose bone flap was removed because of osteomyelitis. We report significant changes in the oscilla.tory CSF flow after. cranioplasty. A moderate increase in venous outflow as well as a two-fold increase in craniocaudal cerebrospinal fluid systolic flow velocity was measured after the skull closure. The changes in the cerebrospinal fluid oscillatory flow at the level of the eraniovertebraIjunction could reflect changes in the compliance of the craniospinal system produced by closure of the cranial defect. [Neural Res 1997; 19: 311–316]     

Magnetic resonance imaging of the brain used to detect early post-partum activation of multiple sclerosis

Post-partum relapses are a frequent phenomenon in multiple sclerosis (MS). The purpose of this study was to evaluate the timing and extent of new or growing T2-lesions after delivery in a cohort of Finnish MS patients. In addition to serial magnetic resonance imaging (MRI), the patients were followed up clinically with determination of relapse rate and expanded disability status scale. The annualized relapse rate was decreased during the last trimester of pregnancy [mean 0.14, standard deviation (SD) 0.14] when compared with the time before pregnancy (mean 0.64, SD 0.14; P  = 0.04) and to time post-partum (mean 1.50, SD 0.45; P  = 0.0002). New or enlarging lesions were detected in the post-partum images in 14 of 28 patients. Gadolinium-enhancing lesions in post-partum MRI were present in eight of 13 patients. There was a significant increase in the number of T2-lesions ( P  = 0.0009), in the total volume of MS-lesions measured from fluid-attenuated inversion recovery images ( P  = 0.0126) and in the number of diffusion weighted imaging hyperintense lesions ( P  = 0.0098) in the post-partum images. The clinical results support the earlier findings of decreased disease activity in late pregnancy. The clinical and MRI findings indicate that post-partum activation is an early and common phenomenon amongst mothers with MS.