Thin section MR study of the basal ganglia in the differential diagnosis between striatonigral degeneration and Parkinson disease

PURPOSE: Signal abnormalities within the putamen in MRI have been related to tissue degeneration in the striatonigral variant of multiple system atrophy (MSA-P). While previous work demonstrated the high specificity of these MR findings, sensitivity rates were unsatisfactory. We evaluated the specificity and sensitivity of an acquisition protocol using thin section MRI to differentiate MSA-P from Parkinson disease (PD). METHOD: Axial 3-mm-thick conventional T2 and proton density spin echo images at the level of basal ganglia were acquired at 1.5 T in 24 patients with MSA-P and 27 patients with PD. RESULTS: We found an abnormal putaminal T2 hypointensity in 21 of 24 MSA-P patients (87.5% sensitivity) and a proton density hyperintensity in 20 of 24 MSA-P patients (83.3% sensitivity). Three among 27 PD patients had an abnormal putaminal T2 hypointensity (88.8% specificity) and there were no proton density abnormalities (100% specificity). CONCLUSION: Our thin section conventional spin echo protocol showed a substantial increase in MR sensitivity compared with previous reports. We believe that a better depiction of even mild signs of degeneration in the putamen may allow a more widespread use of this technique in the differential diagnosis of parkinsonisms.     

MR imaging in progressive supranuclear palsy and Shy-Drager syndrome

Previous reports have suggested that putaminal hypointensity in T2-weighted images at high field strength (1.5 T) magnetic resonance (MR) is a common finding in atypical parkinsonian syndromes, including progressive supranuclear palsy (PSP) and Shy-Drager syndrome (SDS). We have reviewed nine patients with PSP and five with SDS, selected on strict clinical criteria. Only in one PSP patient was abnormal signal intensity (putaminal hypointensity more marked than pallidal) found. However, hypointensity was often marked in the substantia nigra and occasionally in the superior colliculi. Focal midbrain atrophy, involving particularly the upper part of the quadrigeminal plate, was obvious in five cases. In general there was no uniformity of findings and MR appears unable to consistently support the clinical diagnosis of PSP. In SDS patients the findings were more uniform, with hypointensity in the putamen, superior or equal to that of the pallidum. At low or intermediate field strength, there was absence of magnetic susceptibility effect in the putamen, which appeared hyperintense. This was probably because of increased water content due to gliosis and/or cell loss. The constancy of the MR findings in our SDS series suggests a supportive diagnostic role for MR imaging.     

Progressive supranuclear palsy: MRI and pathological findings

Our purpose was to investigate brain atrophy and signal intensity changes on MRI in patients with progressive supranuclear palsy (PSP) and to correlate them with pathological features. We reviewed MRI and brain specimens of six patients with PSP, nine with Parkinson's disease (PD) and six with striatonigral degeneration (SND). Sagittal T1-weighted images showed that four patients with PSP had obvious reduction of anteroposterior midbrain diameter. T2-weighted images demonstrated diffuse high-signal lesions in the tegmentum and tectum of the midbrain of four patients, the upper pontine tegmentum of four, and the lower pontine tegmentum of two, but in no patient with PD or SND. The inferior olivary nuclei gave high signal intensity on T2-weighted images in one patient with PSP These signal intensity changes were consistent with the pathological findings. One patient with PSP showed abnormal signal intensity in the upper pontine tegmentum without atrophy of the midbrain. Midbrain atrophy and diffuse high-signal lesions on T2-weighted images in the tegmentum and tectum of the brain stem are characteristic of PSP     

MR imaging of middle cerebellar peduncle width: differentiation of multiple system atrophy from Parkinson disease

PURPOSE: To prospectively assess if middle cerebellar peduncle (MCP) atrophy, evaluated at magnetic resonance (MR) imaging, can help differentiate multiple system atrophy (MSA) from Parkinson disease (PD). MATERIALS AND METHODS: All participants provided informed consent for participation in the study, which was approved by the institutional review board. Sixteen consecutive patients with MSA, 26 consecutive patients with PD, and 14 healthy control subjects were examined with MR imaging. Images were interpreted independently by two experienced neuroradiologists blinded to clinical information, who visually inspected the images for the presence or absence of putaminal atrophy, putaminal hypointensity, slitlike hyperintensity in the posterolateral margin of the putamen, brainstem atrophy, hyperintensity of the MCP, and cruciform hyperintensity of the pons. Measurements of MCP width on T1-weighted volumetric spoiled gradient-echo images were performed in all subjects. Differences in MCP width among the groups were evaluated by using the Kruskall-Wallis test, followed by the Mann-Whitney U test for multiple comparisons and Bonferroni correction. RESULTS: All patients (mean age, 63.88 years; range, 55-72 years) with MSA had at least one of the features commonly observed in this disease on MR images, whereas control subjects (mean age, 66.93 years; range, 61-77 years) and all but one patient with PD (mean age, 65.31 years; range, 51-79 years) had normal MR images. The average MCP width was significantly smaller in patients with MSA (6.10 mm+/-1.18 [standard deviation]) than in those with PD (9.32 mm+/-0.77, P<.001) or control subjects (9.80 mm+/-0.66, P<.001). CONCLUSION: Measurement of MCP width on MR images may be useful for distinguishing patients with MSA from those with PD.     

P型多系统萎缩的神经影像征象分析

 

目的 探讨MRI T₂WI壳核裂隙征以及壳核扩散加权低信号征、脑桥萎缩、桥臂萎缩在诊断P型多系统萎缩(Parkinsonism type of MSA , MSA-P)中的作用。方法 选取2014-09至2019-07就诊于解放军总医院第六医学中心神经疑难疾病会诊中心的86例MSA患者中诊断为MSA-P型的患者20例,并从影像储存与传输系统(picture achiving and communications system, PACS)上选取年龄性别匹配的健康对照组20例。对MSA-P型患者和健康成人的头颅常规MRI扫描序列,包括轴位及矢状位T₂加权,轴位T₁加权及弥散加权成像序列进行影像学征象分析。对两组患者的脑桥、桥臂萎缩,及壳核扩散加权低信号征,壳核背外侧裂隙征进行评价。结果 20例MSA-P患者中,T₂加权像成像裂隙征70%(14/20),壳核扩散加权低信号征90%(18/20);脑桥萎缩30%(6/20),单侧或双侧桥臂萎缩40%(8/20)。MSA-P型患者组的T₂加权像成像裂隙征及壳核扩散加权低信号征与健康对照组对比,差异有统计学意义(P<0.01)。结论 MSA-P患者T₂加权像成像裂隙征及壳核扩散加权低信号征阳性率明显高于桥臂及脑桥萎缩阳性率,是诊断P型多系统萎缩的主要征象,具有较高的临床诊断价值。

     

Microcystic meningioma: importance of obvious hypointensity on T1-weighted magnetic resonance images

PURPOSE: To investigate the sensitivity and specificity of various magnetic resonance imaging findings for microcystic meningioma. METHODS: Magnetic resonance images of 26 patients with microcystic meningioma (8 from our series and 18 from the literature) and 32 control subjects with other types of meningiomas were evaluated for obvious hypointensity relative to the cerebral cortex on T1-weighted images (T1WIs), obvious hyperintensity relative to the cerebral cortex on T2-weighted images (T2WIs), a radial or sunburst vascular pattern, marginal and reticular enhancement, severe peritumoral brain edema, and the dural tail sign. Differences in the frequencies of these findings between the microcystic and control groups were examined by means of the chi2 test. The sensitivity, specificity, positive predictive value, and negative predictive value of these findings in the diagnosis of microcystic meningioma were calculated. Multivariate analysis of the findings was also performed. RESULTS: The frequencies of obvious hypointensity on T1WI, obvious hyperintensity on T2WI, marginal and reticular enhancement, and severe peritumoral brain edema significantly differed between the microcystic and control groups (all P < 0.005). Sensitivities and specificities of hypointensity on T1WI and hyperintensity on T2WI in the diagnosis of microcystic meningioma were greater than 87%. After multivariate analysis, obvious hypointensity on T1WI was the only significant predictor of microcystic meningioma, with an odds ratio of 75.0 (95% confidence interval, 3.7-1536.0). CONCLUSION: Obvious hypointensity relative to the cerebral cortex on T1WI was the most valuable magnetic resonance finding in the diagnosis of microcystic meningioma.     

Chronic injuries of the spinal cord: assessment with MR imaging

Seventy-six patients with persistent myelopathy secondary to chronic spinal cord injuries underwent examination with magnetic resonance (MR) imaging, the results of which were correlated with neurologic findings. Twenty-one patients received follow-up study during and after the acute stage; 55 patients were examined only at a chronic stage. Spinal cord abnormalities were seen in 48 patients according to five patterns: (a) normal signal intensity on T1- and T2-weighted images (pattern N/N, n = 28), (b) normal signal intensity on T1-weighted and hyperintensity on T2-weighted images (pattern N/Hi, n = 18), (c) hypointensity on T1-weighted and hyperintensity on T2-weighted images (pattern Lo/Hi, n = 17), (d) cord atrophy (n = 5), and (e) longitudinal syrinx formation with hypointensity on T1- and hyperintensity or isointensity on T2-weighted images (n = 8). Patients with pattern N/N had only slight neurologic damage and an excellent prognosis. Patients with pattern N/Hi had mild neurologic impairment, frequently associated with cord compression. Patients with pattern Lo/Hi had the worst prognosis. Atrophy was observed in patients with a long history of myelopathy.     

Putaminal lesion in multiple system atrophy: postmortem MR-pathological correlations

INTRODUCTION: Posterior putaminal atrophy, putaminal T2-hyper and/or hyposignal changes have been observed in patients with multiple system atrophy (MSA) with parkinsonism. METHODS: Postmortem T2-weighted images were compared with histological findings in seven autopsy-proven cases of putaminal lesions of MSA. All cases were evaluated on 1.5T magnetic resonance imaging (MRI) scanners and three cases were evaluated on 3T scanners. RESULTS: There were three types of putaminal changes: Type 1, mild putaminal atrophy and isointensity; Type 2, putaminal atrophy and diffuse hyperintensity with a hyperintense putaminal rim (HPR); Type 3, putaminal atrophy and iso-or-hypointensity with HPR. The signal intensities of the putamen in Types 1 and 3 were more hypointense on 3T images than on 1.5T images. In Type 1, mild putaminal atrophy showed mild neuronal loss and gliosis and diffuse ferritin deposition. In Types 2 and 3, the areas of putaminal atrophy, severe in the posterior region, showed severe neuronal loss and gliosis, many pigments that were positive for ferritin and Fe (3+) and diffuse ferritin deposition. Although, tissue rarefaction was more severe in Type 2 than in Type 3, pigment deposition was more severe in Type 3. The HPR showed a severe loss of myelin and axons with tissue rarefaction of the external capsule or putaminal rim in Types 2 and 3. CONCLUSION: Posterior putaminal atrophy reflects neuronal loss and gliosis. While putaminal iso-or -hypointensity reflects diffuse ferritin and Fe(3+) deposition, hyperintensity reflects tissue rarefaction. The HPR reflects degeneration of the putaminal lateral margin and/or external capsule. These findings reflect characteristic histological findings of MSA with parkinsonism.     

Morning glory sign: a particular MR finding in progressive supranuclear palsy.

BACKGROUND AND PURPOSE: We have encountered a peculiar atrophic change in the midbrain in some patients with parkinsonian syndromes. We discovered these patients had vertical supranuclear gaze-palsy, an eye movement disorder. The purpose of this study was to elucidate whether this atrophic pattern of the midbrain (which we have termed morning glory sign) is related to the vertical eye movement disorder, in particular to progressive supranuclear palsy (PSP). METHODS: We reviewed T2-weighted axial images obtained from 42 patients with parkinsonian syndromes, including five patients with PSP, 23 patients with Parkinson's disease, and 14 patients with multiple system atrophy (MSA). We focused on a specific atrophy of the midbrain, the morning glory sign, which is a concavity of the lateral margin of the tegmentum of the midbrain. RESULTS: The morning glory sign was detected in four of the five patients with PSP and in one (striatonigral degeneration; SND) of the14 patients with MSA. All morning glory sign patients had vertical supranuclear gaze-palsy, as did the one PSP patient without the morning glory sign. Vertical supranuclear gaze-palsy was seen in no other patients (23 patients with Parkinson's disease and 13 patients with MSA) who lacked the morning glory sign. CONCLUSIONS: Morphologically, the morning glory sign is believed to be related to vertical supranuclear gaze-palsy. This sign should be considered a useful clue when diagnosing PSP.     

MRI在鉴别多系统萎缩与帕金森病中的价值

目的 探讨常规MR在鉴别多系统萎缩(MSA)与帕金森病(PD)中的价值. 资料与方法 回顾性分析经临床诊断为MSA的26例患者常规MR资料,另外搜集经临床诊断为PD的27例患者常规MR资料为对照组. 结果 12项MR表现中,幕下的MR表现有十字征、小脑中脚高信号、桥脑高信号、小脑萎缩、小脑中脚萎缩、延髓萎缩、桥脑萎缩、第四脑室扩大、桥前池扩大.幕上的MR表现有壳核边缘高信号、壳核高信号、壳核萎缩.幕下的MR表现鉴别MSA和PD均有统计学意义(P＜0.05).而幕上的MR表现鉴别MSA和PD均无统计学意义(P＞0.05).敏感性较高的是小脑中脚萎缩和小脑萎缩,特异性和阳性预测值较高的是十字征、小脑中脚高信号. 结论 常规MR有助于MSA与PD鉴别诊断.     

CT and MR imaging characteristics of intravestibular lipoma

BACKGROUND AND PURPOSE: Intracranial lipomas are uncommon congenital malformations that most often are asymptomatic. A rare subset of intracranial lipomas arises within the vestibule of the inner ear, which can cause sensorineural hearing loss. We present the CT and MR imaging characteristics of lipomas within the vestibule of the inner ear and propose a pathogenetic mechanism for this malformation. METHODS: We retrospectively reviewed five cases of vestibular lipoma. T1-weighted axial conventional spin-echo and T2-weighted axial fast spin-echo sequences were performed in all five cases. Four patients underwent T1-weighted fat-saturated imaging, and one underwent CT scanning with Hounsfield units measured. RESULTS: Four female patients ranging in age from 10 to 40 years and one 26-year-old male patient had sensorineural hearing loss. Two patients had progressive high-frequency loss; one, sudden-onset high-frequency loss; and two, congenital high-frequency loss. All had lesions within the vestibule that displayed hyperintensity on T1-weighted images, isointensity to slight hypointensity on T2-weighted fast spin-echo images, hypointensity with fat saturation, and fat attenuation on CT scans. Three of the cases were associated with lipoma of the cerebellopontine angle. In none of these cases were the cerebellopontine angle and labyrinthine lipomas contiguous. CONCLUSION: Intravestibular lipoma is considered when a focal hyperintense lesion is identified within the vestibule of the inner ear on T1-weighted MR images. Lesion hypointensity on fat-saturated T1-weighted MR images verifies its lipomatous nature and separates it from intralabyrinthine hemorrhage or highly proteinaceous fluid.     

Significance of apparent diffusion coefficient measurement for the differential diagnosis of multiple system atrophy, progressive supranuclear palsy, and Parkinson's disease: evaluation by 3.0-T MR imaging

Introduction

The clinical differentiation of Parkinson’s disease (PD) from multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) may be challenging, especially in their early stages. The aim of this study was to evaluate the utility of apparent diffusion coefficient (ADC) measurement to distinguish among these degenerative disorders.

Methods

Twenty-five MSA, 20 PSP, and 17 PD patients and 18 healthy controls were retrospectively studied. Axial diffusion-weighted and T2-weighted images were obtained using a 3-T MR system. Regions of interest (ROIs) were precisely placed in the midbrain, pons, putamen, globus pallidus, caudate nucleus, thalamus, superior cerebellar peduncle, middle cerebellar peduncle, cerebellar white matter, and cerebellar dentate nucleus, and the regional ADC (rADC) value was calculated in each ROI.

Results

In MSA, rADC values in the pons, middle cerebellar peduncle, cerebellar white matter, and cerebellar dentate nucleus were significantly higher than in PSP, PD, and controls. Furthermore, rADC values in the posterior putamen were significantly higher in MSA than in PSP and controls. In PSP, rADC values were significantly higher in the globus pallidus and midbrain than in MSA, PD, and controls. Furthermore, rADC values in the caudate nucleus and superior cerebellar peduncle were significantly higher in PSP than in MSA and controls. In PD, there were no significant differences in the rADC values compared to in MSA, PSP, and controls in all regions.

Conclusion

Evaluation of rADC values in characteristic lesions in MSA, PSP, and PD by placing ROIs using 3-T systems can provide useful additional information for differentiating these disorders.     

MRI在肝脏占位性病变诊断中的应用

目的:探讨MRI在肝脏占位病变诊断中的应用价值。材料与方法:对98例肝肿瘤患者的MRI影像分析了图像质量、病灶显示清晰度及病变信号特征。全部病例均用1.0T超导磁共振机检查,采用自旋回波(SE)及快速自旋回波(TSE)序列摄取横轴位T_1及T_2加权像。36例患者接受了Gd-DTPA增强,其中12例进行了动态增强检查。结果:图像优良者89％,较差者占11％。MRI能显示的最小病灶为0.5～1.4cm。转移瘤均呈不同程度的长T_1、长T_2信号,信号不均匀,无包膜。肝细胞癌呈不均匀长T_2信号,T_1加权像上7例呈等信号或轻度高信号,其余呈轻度低信号。5例可清晰显示包膜,3例可见门静脉内瘤栓形成。海绵状血管瘤呈均匀性长T_1低信号、长T_2显著高信号,轮廓清晰,边缘光整或呈分叶状。结论:MRI对肝占位病变的诊断敏感度高,特异性好,对发现病变及定性、定量诊断均具有重要价值,值得广泛应用。     

Imaging of benign hypervascular hepatocellular nodules in alcoholic liver cirrhosis: differentiation from hypervascular hepatocellular carcinoma

OBJECTIVES: To retrospectively describe imaging analyses of benign hypervascular hyperplastic liver nodules (HHN) that resulted from alcoholic liver cirrhosis and to examine the possibility of imaging differentiation between these nodules and hypervascular hepatocellular carcinoma (HCC). METHODS: Ten histopathologically confirmed HHN arise in alcoholic liver cirrhosis, and 9 HCC were examined. Magnetic resonance imaging (MRI) (10 HHN and 9 HCC), superparamagnetic iron oxide-enhanced T2-weighted MRI (6 HHN and 4 HCC), and dual-phase computed tomography hepatic arteriography (5 HHN and 6 HCC) were performed, respectively. RESULTS: On T1-weighted magnetic resonance images, 7 HHNs showed hyperintensity and 3 showed iso- to hypointensity, and all HCCs showed hypointensity compared with surrounding liver. On T2-weighted magnetic resonance images, 2 HHNs showed hyperintensity and 8 showed iso- to hypointensity. In contrast, 1 HCC showed hypointensity and 8 showed hyperintensity. On superparamagnetic iron oxide-enhanced T2 MRI, all HHNs showed iso- to hypointensity, and all HCCs showed hyperintensity. All HHN and HCCs subjected to dual-phase computed tomography hepatic arteriography showed enhancement on early-phase images and coronalike enhancement on late-phase images. CONCLUSIONS: Imaging findings of highly-well differentiated HCCs possibly overlap with HHN. So, for correct diagnosis of HHN, at first, we should suspect HHN based on clinical findings and MRI findings, and then perform core needle biopsy to verify the radiological diagnosis.     

椎管内微小占位性病变的MRI诊断

目的:研究椎管内微小占位性病变的MRI特征及其对病变定性、定位诊断的意义。材料与方法:24例椎管内微小占位性病变患者(男12例,女12例,年龄23～67岁,平均29.1岁)均经PHILIPS 1.0NT型MR仪行常规T_1WI、T_2WI磁共振成像,其中6例又经Gd-DTPA增强扫描。全部病例的椎管内占位病变均经病理证实,并对其MRI表现进行了回顾性分析。结果:24例的病变经病理证实,18例为胚胎源性肿瘤(10例表皮样囊肿,4例皮样囊肿,4例畸胎瘤),4例为神经源性肿瘤(3例神经鞘瘤,1例神经纤维瘤),以及脊膜瘤与脂肪瘤各1例。各种占位性病变的MRI表现随其不同的组织学来源而有很大差别。表皮样囊肿多为均质长T_1长T_2信号。皮样囊肿以短T_1,长T_2信号为主。畸胎瘤呈混杂信号。神经鞘瘤为T_1WI低信号、T_2WI高信号,Gd-DTPA增强扫描后,囊壁均匀强化,偶见强化附壁结节。神经纤维瘤呈均质长T_1、长T_2信号,Gd-DTPA增强扫描后,病灶呈异常对比增强。脊膜瘤呈长T_1、稍长T_2信号,Gd-DTPA增强扫描后,病灶呈异常对比强化,并见局部硬脊膜增厚强化而形成的硬膜尾征。结论:各种病变的MRI表现随其组织学来源不同而有明显差异,它们在椎管内微小占位性病变的定性、定位诊断中起着重要作用,其诊断准确性优于X线椎管造影与CT。     

Usefulness of 3D-PRESTO imaging in evaluating putaminal abnormality in parkinsonian variant of multiple system atrophy

Introduction  

Principles of echo shifting with a train of observations (PRESTO) sequence has long echo time which emphasizes the effect of T2* relaxation time and contribute to its high sensitivity to the susceptibility change. The aim of our study was to evaluate the ability of 3D-PRESTO sequence in detecting putaminal hypointensity in patients with parkinsonian variant of multiple system atrophy (MSA-P) and in discriminating between MSA-P and Parkinson's disease (PD).     

Magnetic resonance imaging features of fractures using the short tau inversion recovery (STIR) sequence: correlation with radiographic findings

The MRI characteristics of fractures have been described on the basis of spin echo (SE) images emphasizing T1 and T2 contrast. These previous studies were carried out for injuries in which radiographic proof was often lacking. In comparison with SE images, short tau inversion recovery (STIR) images have been shown to provide superior contrast between normal and abnormal marrow. To determine the MRI characteristics of fracture using STIR pulse sequences, we reviewed 28 patients who had radiographic evidence of fracture and were examined with T1-weighted SE and STIR sequences. MRI marrow signal abnormalities were demonstrated at all fracture sites ranging in age from less than 24 h to 8 weeks. The extent of marrow signal abnormalities exceeded the size of corresponding radiographic findings of fracture in all cases. The MRI features of fractures on T1-weighted SE images consisted of irregular intramedullary zones of hypointensity. On STIR images a corresponding zone of hyperintensity extended to the outer cortical margin. Intramedullary lines of hypointensity extending to the inner cortical margin were identified within the hyperintense marrow abnormality on STIR images in 64% of the fractures. The results of this study show that MRI using T1-weighted SE and STIR sequences can consistently demonstrate prominent signal abnormalities at fracture sites including those in which radiographic signs are subtle.     

A true aneurysm of the femoral artery in acromegaly

We report on an acromegalic patient who developed a true aneurysm in the right femoral artery. Plain computed tomography (CT) showed a soft tissue mass with low density adjacent to the right femoral artery. T1-weighted magnetic resonance (MR) images exhibited the lesion with moderate hypointensity peripherally, and hypointensity centrally. T2-weighted images showed the lesion to have areas of hypointensity, moderate hyperintensity, and marked hyperintensity. Surgery revealed an ectasia of the common femoral artery and a true aneurysm from the lateral femoral circumflex artery.     

Premature aging in persons with Down syndrome: MR findings.

PURPOSETo determine whether persons with Down syndrome have features of premature aging on routine MR imaging sequences.METHODSSixty MR studies (in 30 persons with Down syndrome and 30 age- and sex-matched control subjects) were reviewed retrospectively by two blinded examiners. Sagittal T1-weighted and axial T2-weighted spin-echo images were evaluated for the presence and severity of three markers of brain aging: atrophy, white matter lesions, and T2 hypointensity of the basal ganglia, referenced to the examiner''s internal standard of normal for that age and sex.RESULTSPersons with Down syndrome had higher prevalence and severity of the three markers studied than the control subjects. Atrophy and white matter lesions increased in prevalence with age; abnormal T2 hypointensity of the basal ganglia was more equally distributed with age.CONCLUSIONPersons with Down syndrome have features of premature aging detectable at routine MR imaging.     

Hyperintense putaminal rim sign is not a hallmark of multiple system atrophy at 3T

BACKGROUND AND PURPOSE: Hyperintense putaminal rim (HPR) on the T2-weighted imaging, which has been observed in our daily practice while reading 3T brain images, has been described as a finding typical of multiple system atrophy (MSA). We hypothesized that the HPR sign is not an exclusive hallmark of MSA at a high magnetic field strength, but rather may be a normal finding. METHODS: Ten consecutive clinically healthy age-matched adults who showed recognizable HPR at 3T were subsequently examined on a 1.5T imaging system within 2 hours. MR examination included axial T2-weighted fast spin-echo (FSE), fluid attenuated inversion recovery (FLAIR) on a 3T scanner, and equivalent T2-weighted FSE at 1.5T. MR images were obtained parallel to the intercommissural plane. All the images were interpreted by 2 experienced neuroradiologists. RESULTS: All 10 subjects (3 men and 7 women; aged 52 +/- 6.1 years [range, 44-61 years], expressed as mean +/- SD) with the positive HPR sign on axial T2-weighted FSE at 3T had negative findings at 1.5T. Such hyperintense rim was also vague or absent on the 3T-FLAIR images. CONCLUSION: Our data suggest that the HPR at 3T scans is a nonspecific, normal finding. FLAIR may be helpful in discriminating between normal subjects and patients with MSA in case of isolated HPR at 3T.