Does High-field MR Imaging Have an Influence on the Classification of Patients with Clinically Isolated Syndromes According to Current Diagnostic MR Imaging Criteria for Multiple Sclerosis?

BACKGROUND AND PURPOSE: Current MR imaging criteria for multiple sclerosis (MS) do not specify the magnetic field strength. The aim of this study was to investigate whether different MR imaging field strengths, specifically high-field MR imaging, have an impact on the classification of patients with clinically isolated syndromes suggestive of MS, according to MR imaging and diagnostic criteria. METHODS: In a prospective intraindividual comparative study, we examined 40 patients with clinically isolated syndromes (CIS) consecutively with a 1.5 T and 3T MR imaging system, including axial sections of T2 turbo spin-echo, fluid-attenuated inversion recovery, and T1 spin-echo, before and after injection of gadolinium-diethylene-triaminepentaacetic acid. Constant resolution parameters were used for both field strengths. High-signal-intensity white matter lesions with a size of >3 mm were counted and categorized according to their anatomic location in infratentorial, callosal, juxtacortical, periventricular, and other white matter areas. Assessment of the fulfilled Barkhof MR imaging and McDonald diagnostic criteria was made separately for both field strengths in every patient. RESULTS: Eleven patients fulfilled more MR imaging criteria at 3T. Two of these patients fulfilled the criterion of dissemination in space (DIS) according to the first definition of McDonald criteria, which is based on imaging criteria alone. Another patient had DIS only at 3T, according to the second definition of the McDonald criteria including CSF parameters. CONCLUSION: MR field strength, specifically high-field MR imaging, has a substantial influence on the classification of patients with CIS according to imaging and a mild influence on the classification according diagnostic criteria for MS, leading to consequences for prognostic classification, imaging guidelines, and clinical trials.     

儿童急性播散性脑脊髓炎与临床孤立综合征的临床及影像学比较研究

目的探讨急性播散性脑脊髓炎(acute disseminated encephalomyelitis,ADEM)与临床孤立综合征(clini-cally isolated syndrome,CIS)的鉴别诊断要点。资料与方法搜集39例患儿首发中枢神经系统脱髓鞘病变时的临床及影像学资料。其中CIS 18例,包括女13例,男5例;ADEM共21例,其中女8例,男13例。平均随访时间4.2年,最短随访时间为2年。由一名儿科神经医师对CIS及ADEM的临床表现进行了归类总结。由一名资深神经影像学医师对患者ADEM及CIS头颅MRI表现进行分析,内容包括病灶的位置、大小、形态。对计数资料采用Fisher精确检验,对计量资料进行非参数Mann-Whitney U检验。分别应用几种CIS的诊断标准对患儿进行评价,比较分析每种标准诊断的特异性、敏感性、阳性预测值及阴性预测值。结果 39例儿童ADEM与CIS患者中,ADEM发病年龄小,平均约(6.14±3.41)岁;CIS平均发病年龄(10.05±2.87)岁,两者之间差异有统计学意义(P=0.000);ADEM临床表现以发热和运动障碍为主,分别占76%和71%,高于CIS的33%和22%(P=0.011,0.004)。而CIS中视力障碍及脑脊液寡克隆带阳性出现率分别占50%和61%,与ADEM的0%和24%比较,差异具有统计学意义(P=0.000,0.025)。随访中儿童ADEM的改良的Rankin量表评分不如CIS。影像学特征中,与CIS比较,中央白质病变及脑萎缩在ADEM中表现更为明显,分别占100%和38%(P=0.001,0.023);ADEM病灶分布相对对称。CIS的视神经及脊髓病变出现率分别为22%、17%,ADEM未出现此类病变(P=0.037,P=0.089)。"黑洞"在CIS中具有显著特异性,与ADEM比较差异具有统计学意义(P=0.037)。Callen诊断MS的标准敏感性最高,为87%。KIDMUS(2个均满足)MS诊断标准及Callen的鉴别MS与ADEM标准特异性均较高,分别为92%和90%。KID-MUS敏感性最差,为33%。Barkhof的成人MS标准在儿童中敏感性及特异性均较低,分别为22%和57%。结论临床及影像学特征的结合,可以帮助早期诊断与鉴别ADEM与CIS。在诊断CIS时应该用Callen诊断MS标准为主,而鉴别ADEM和CIS时可以用Callen的鉴别标准。     

Differentiation of multiple sclerosis from other inflammatory disorders and cerebrovascular disease: value of spinal MR imaging

PURPOSE: To determine the value of magnetic resonance (MR) imaging in the spinal cord to differentiate multiple sclerosis (MS) from other inflammatory disorders and cerebrovascular diseases (together, other neurologic disease [OND]). MATERIALS AND METHODS: The study population included 66 patients with OND and 25 patients with MS, who were matched for age, sex, and symptom duration or severity. Brain MR imaging included gadolinium-enhanced T1-weighted and dual-echo T2-weighted spin-echo sequences to assess the number, size, and appearance of lesions, contrast enhancement, and compatibility with diagnostic criteria for MS. Spinal cord MR imaging included cardiac-triggered gadolinium-enhanced sagittal T1-weighted spin-echo and dual-echo T2-weighted sequences to assess the general appearance (normal, focal lesion, diffuse abnormality) and number or size of focal lesions. Images obtained in MS and OND patients were compared. Specificity, sensitivity, accuracy, and positive and negative predictive values with MR images were calculated. RESULTS: Brain images were abnormal in all MS patients and in 65% of OND patients. Abnormal cord images were found in 92% of MS and 6% of OND patients. The combination of brain and spinal cord images increased accuracy of diagnosis compared with use of brain images alone. CONCLUSION: In contrast to MS, cord lesions are very uncommon in OND. This finding can help differentiate these disorders.     

A novel method for automatic determination of different stages of multiple sclerosis lesions in brain MR FLAIR images.

It is very important to detect stages of multiple sclerosis (MS) lesions in order to exactly quantify involved voxels. In this paper, a novel method is proposed for automatic detection of different stages of MS lesions in the brain magnetic resonance (MR) images, in fluid attenuated inversion recovery (FLAIR) studies. In the proposed method, firstly, MS lesion voxels are segmented in FLAIR images based on adaptive mixtures method (AMM) and Markov Random Field (MRF) model. Then, signal intensity of each lesion voxel is modeled as a linear combination of signals related to the normal and also abnormal parts, in the voxel. By applying an optimal threshold, voxels with new intensities are primarily classified into two stages: previously destructed (chronic) and on going destruction (acute) lesions. Finally, the acute lesions, according to their activities, are classified, by another optimal threshold, into two new stages, early and recent acute. Evaluation of the proposed method was performed by manual segmentation of chronic and enhanced (early) acute lesions in gadolinium enhanced T1-weighted (Gad-E-T1-w) images by studying T1-weighted (T1-w) and T2-weighted (T2-w) images, using similarity criteria. The results showed a good correlation between the lesions segmented by the proposed method and by experts manually. Thus, the suggested method is useful to reduce the need for paramagnetic materials in contrast enhanced MR imaging which is a routine procedure for separation of acute and chronic lesions.     

Contribution of magnetic resonance imaging to the diagnosis and monitoring of multiple sclerosis

Magnetic resonance (MR) imaging is an extremely sensitive modality for detecting focal changes to the white matter (WM) in patients with multiple sclerosis (MS). For this reason, it has become an integral part of the diagnostic workup of patients with clinically isolated syndromes who are at risk of developing definite MS, and it is always recommended in patients with definite MS to confirm the diagnosis and monitor the disease course. Crucial to the use of MR imaging for diagnostic purposes is the identification of lesion features — in terms of site, shape and size — that may be considered suggestive or typical for MS, and thus help in the differential diagnosis with other neurological diseases with similar clinical presentation to MS. This need has led to the publication of several guidelines for characterising MS lesions on both dualecho (T2 and proton density) and T1-weighted sequences after administration of contrast material. Developments in clinical research into MS have highlighted the need to formulate a diagnosis as far as possible on the basis of objective and reproducible criteria. Currently, when making a clinical diagnosis and monitoring patients with suspected MS, neurologists and neuroradiologists make use of specific diagnostic criteria that have changed over the years and will probably continue to be updated. It is therefore crucial for radiologists to become familiar with these criteria in order to improve the quality of their diagnostic assessment. In patients with a definite diagnosis of MS, on the other hand, the main problem is to define standard procedures for monitoring the course of the disease and response to pharmacological treatments. even though no guidelines currently exist, it is possible to suggest some strategies to improve the assessment in this setting.     

Iron deposition in multiple sclerosis lesions measured by susceptibility-weighted imaging filtered phase: a case control study

Purpose:

To investigate phase lesions identified on susceptibility‐weighted imaging (SWI)‐filtered phase images in patients with multiple sclerosis (MS), clinically isolated syndrome (CIS) and healthy controls (HC). To relate phase lesion characteristics to other clinical and MRI outcomes.

Materials and Methods:

95 relapsing‐remitting (RR), 40 secondary‐progressive (SP) MS patients, as well as 19 CIS patients and 49 age‐ and sex‐matched HC, were scanned on a 3T scanner. Phase‐, T1‐, and T2‐lesion characteristics were determined. Overlap of T1‐ and T2‐weigthed imaging (WI) lesions with phase lesions (T1P and T2P), as well as brain atrophy outcomes, was assessed.

Results:

MS patients showed significantly greater numbers and larger volume of phase lesions, compared with HC (P < 0.001). 23.6% of T2 lesions overlapped with phase lesions, whereas the same figure for T1 lesions was 37.3%. Conversely, 33.4% and 69.7% of phase lesions were not visible on T2‐ or T1‐WI, respectively. Phase, T1P and T2P lesions were not related to clinical outcomes, but phase lesions were related to ventricular enlargement.

Conclusion:

Phase lesions were present in both MS and CIS patients, and showed partial overlap with lesions observed using conventional MRI. The role of phase lesions in clinical progression remains unclear and should be further explored. J. Magn. Reson. Imaging 2012;36:73–83. © 2012 Wiley Periodicals, Inc.     

Spinal cord magnetic resonance imaging in suspected multiple sclerosis

We examined the value of spinal cord magnetic resonance imaging (MRI) in the diagnostic work-up of multiple sclerosis (MS). Forty patients suspected of having MS were examined within 24 months after the start of symptoms. Disability was assessed, and symptoms were categorized as either brain or spinal cord. Work-up further included cerebrospinal fluid analysis and standard proton-density, T2-, and T1-weighted gadolinium-enhanced brain and spinal cord MRI. Patients were categorized as either clinically definite MS (n = 13), laboratory-supported definite MS (n = 14), or clinically probable MS (n = 4); four patients had clinically probable MS, and in nine MS was suspected. Spinal cord abnormalities were found in 35 of 40 patients (87.5 %), consisting of focal lesions in 31, only diffuse abnormalities in two, and both in two. Asymptomatic spinal cord lesions occurred in six patients. All patients with diffuse spinal cord abnormality had clear spinal cord symptoms and a primary progressive disease course. In clinically definite MS, the inclusion of spinal imaging increased the sensitivity of MRI to 100 %. Seven patients without a definite diagnosis had clinically isolated syndromes involving the spinal cord. Brain MRI was inconclusive, while all had focal spinal cord lesions which explained symptoms and ruled out other causes. Two other patients had atypical brain abnormalities suggesting ischemic/vascular disease. No spinal cord abnormalities were found, and during follow-up MS was ruled out. Spinal cord abnormalities are common in suspected MS, and may occur asymptomatic. Although diagnostic classification is seldom changed, spinal cord imaging increases diagnostic sensitivity of MRI in patients with suspected MS. In addition, patients with primary progressive MS may possibly be earlier diagnosed. Finally, differentiation with atypical lesions may be improved. Received: 21 April 1999; Revised: 3 August 1999; Accepted: 7 August 1999     

Increased accumulations of AMsopropyl-p-[123I]-iodoamphetamine related to tumefactive multiple sclerosis

We present a 21-year-old woman with tumefactive multiple sclerosis (MS) that exhibited a rapidly progressive course. There were multiple tumor-mimicking contrast-enhance lesions with surrounding edema and mass effect on magnetic resonance imaging. Both early and delayed brain single photon emission computed tomography (SPECT) with N-isopropyl-p-[123I]-iodoamphetamine demonstrated increased accumulations of the tracer and a high retention on the lesions. The SPECT findings represent a diagnostic pitfall for distinguishing MS from malignant brain tumors in patients with intracranial tumor-like lesions.     

Assessment of multiple sclerosis lesions by magnetic resonance imaging

Fifty patients clinically suspected to have multiple sclerosis (MS), who were classified by Schumacher's criteria into three clinical categories (definite, probable, or possible MS), underwent complete brain magnetic resonance (MR) scans. The T2-weighted spin echo (SE) pulse sequence was more sensitive than inversion recovery (IR) in detecting MS lesions. Greater than 50% of the lesions demonstrated by SE were missed on the corresponding IR slices. However, lesions in the brainstem were more readily assessed using IR. MS lesions appeared larger on SE than on IR. Fifty-five percent of SE-demonstrated lesions were 1 to 2 cm or larger in size, while only 32% of IR-demonstrated lesions were greater than 1 cm. Axial and coronal planes of study demonstrated the same number, size, and location of lesions.     

Magnetization transfer imaging in patients with clinically isolated syndromes suggestive of multiple sclerosis

BACKGROUND AND PURPOSE: In patients with multiple sclerosis (MS), reduced magnetization transfer ratios (MTRs) have been reported in white matter that appears normal on studies obtained with conventional imaging techniques. The stage in the disease when this first becomes detectable is unclear. The purpose of this study was to measure the MTR of normal-appearing white matter (NAWM) and lesions in patients with clinically isolated syndromes (CIS), many of whom are at the earliest stages of MS, and to determine the prognostic value of any observed changes. METHODS: Twenty-seven CIS patients and 13 matched control subjects were studied. The mean MTR was measured from 10 regions of NAWM and, when present, from lesions. The patients were followed-up clinically for a median of 12 months. RESULTS: There was no significant difference in the mean MTR between NAWM in control subjects (38.5% units) and that in CIS patients (38.4% units). After 12 months' follow-up, MS developed in 26% of the patients. The MTR of NAWM in these patients did not differ from that of the other patients or the control subjects. CONCLUSION: The reduced MTR in NAWM, described in established MS, was not detectable in patients with CIS. MTR did not provide prognostic information for this short period of follow-up.     

Magnetic resonance imaging of liver lesions: exceptions and atypical lesions

On state-of-the-art magnetic resonance imaging, most lesions can be detected and characterized with confidence according to well-known criteria. However, atypical characteristics in some common lesions and the incidental encounter with rare lesions may pose diagnostic difficulties. In this article, six challenging hepatic lesions will be discussed and evaluated on the most important magnetic resonance imaging sequences, with histological correlation when available. In addition, the background information concerning these lesions will be described based on the most recent available literature. By reading this article, the reader will be able to (1) categorize the lesion in solid and fluid-containing lesions, based on the T2 signal intensity; and (2) define the benign or malignant nature of the lesion, in relation to the signal intensity and dynamic enhancement pattern, despite the presence of atypical characteristics of some lesions.     

Interobserver agreement for diagnostic MRI criteria in suspected multiple sclerosis

MRI is the paraclinical test most widely used to support the diagnosis of multiple sclerosis (MS). We evaluated interobserver agreement in applying diagnostic criteria to MRI obtained at first presentation. Five experienced observers scored 25 sets of images consisting of unenhanced T2- and gadolinium-enhanced T1-weighted images (approximately half the sets were normal). We scored frontal, parietal, temporal, occipital, infratentorial and basal ganglia lesions and the total number of lesions on T2-weighted images; periventricular, callosal, juxtacortical and ovoid lesions and those > 5 mm in maximum diameter; contrast-enhancing and hypointense lesions. Based on a combination of imaging findings patients were classified as compatible or not compatible with MS according to composite criteria. Observer concordance was characterised by weighted kappa values (ϰ) and mean average difference to the median (MADM) scores. Using the raw scores, there was poor agreement for the total number of lesions on T2-weighted images, and for occipital, oval, juxtacortical and hypointense lesions. Moderate agreement was found for frontal, callosal, basal ganglia and large lesions on T2 weighting. Good agreement was attained for parietal, temporal, infratentorial and periventricular lesions. After dichotomisation according to accepted cut-off values, most criteria performed better, especially the number of lesions on T2-weighted images (P < 0.05). Good agreement was found for the criteria of Paty and Fazekas and moderate agreement for those of Barkhof. While experienced observers may not agree on the total number of lesions, they show quite good agreement for commonly used cut-off points and elements in the composite criteria. This validates the use of MRI in the diagnosis of MS, and the use of dichotomised and composite criteria. Reveived: 19 October 1998 Accepted: 17 November 1998     

Prognostic value of MR and magnetization transfer imaging findings in patients with clinically isolated syndromes suggestive of multiple sclerosis at presentation

BACKGROUND AND PURPOSE: The extent of abnormalities on T2-weighted MR images of the brain of patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS) at presentation is associated with an increased risk of developing clinically definite MS (CDMS). We evaluated whether subtle changes outside T2-visible lesions are present in the brain of these patients and whether their extent increases the risk of subsequent development of CDMS. METHODS: Dual-echo, T1-weighted, and magnetization transfer (MT) images of the brain were obtained from 24 patients with CIS at presentation. These patients were followed up for a mean period of 33 months (range, 25-42 months). Twenty age- and sex-matched healthy volunteers served as control subjects. To create MT histograms of the normal-appearing brain tissue (NABT), macroscopic lesions were segmented from dual-echo images, were superimposed automatically, and were nulled out from the coregistered and scalp-stripped MT ratio (MTR) maps. The following MTR histogram-derived measures were considered: average MTR, MTR(25), MTR(50), MTR(75), peak height, and peak position. T2 and T1 lesion loads, average lesion MTR, and brain volume were also measured. RESULTS: Patients with CIS had lower average NABT-MTR (P < .0001) and peak position (P = .002) than did control volunteers, but patient brain size was similar to that of volunteers. At follow-up, 10 (41%) patients developed CDMS. Patients who developed CDMS during the follow-up period had higher T2 lesion volume (P = .003) and lower average NABT-MTR (P = .005) and peak position (P = .006) than did those who did not develop CDMS. T2 lesion volume (odd ratio, 3.54; P = .0005) and average NABT-MTR (odd ratio, 0.81; P = .01) were independent predictors of the subsequent development of CDMS. CONCLUSION: Subtle changes occur outside lesions visible on conventional MR images among patients with CIS suggestive of MS at presentation. The greater the extent of such abnormalities is, the higher is the risk of subsequent development of CDMS.     

脊髓型临床孤立综合征的临床及MRI分析

目的 探讨脊髓型临床孤立综合征(CIS)的临床及磁共振成像(MRI)特征.方法 回顾分析63例临床早期表现为脊髓型CIS的多发性硬化(MS)患者的MRI表现及扩展的功能障碍状况量表(EDSS)评分.结果 52.9%的MS患者在早期表现为脊髓型CIS,其中88.9%以急性或亚急性起病,42.9%的首发症状为孤立的感觉障碍,54.9%为颈髓受累.首次MRI阳性率达91.1%,其中35.3%存在"多灶性"损害,45.1%病变范围在2个椎体节段内,81.7%的独立病灶在矢状位的长度不超过2个椎体高度,89.0%在轴位不超过脊髓横径的1/2.基线MRI的病灶数量、面积与确诊时的EDSS评分有正相关关系;皮质类固醇激素冲击治疗前后的EDSS评分有统计学差异(P=0.003).结论 脊髓型CIS以急性、亚急性起病、颈髓受累多见,脊髓损害不完全,MRI可有"多灶"损害,早期病灶定量分析对评估预后有一定价值,皮质类固醇激素冲击治疗能有效缓解症状.     

3.0T磁共振成像在甲状腺良恶性病变鉴别诊断中的价值研究

目的 探讨磁共振成像在甲状腺良恶性病变鉴别中的应用价值.方法 研究对象为2010年8月～2011年8月我院收治的甲状腺病变48例患者、54个病灶,经Philips 3.0T磁共振成像,比较分析T1WI、T2 WI、DWI(b值为150、300和500s/mm2)及动态增强中良性病灶及恶性病灶的MRI表现,并与病理对照.结果 T1 WI像良性病变呈等及略高信号,恶性病变为不均匀略高信号;T2 WI像良恶性病变均为略高信号,无统计学差异(P＞0.05);DWI成像(良性病变:b值为150时ADC值为2.489±0.442、b值为300时ADC值为1.974±0.369、b值为500时ADC值为1.649±0.445;恶性病变:b值为150时ADC值为1.733±0.326、b值为300时ADC值为1.399士0.258、b值为500时ADC值为1.214±0.302),具有统计学差异(P＜0.05).T1WI动态增强良性病变呈流出型强化曲线,恶性病变呈延迟性消退型曲线,具有一定特征性.结论 磁共振成像对甲状腺良恶性病变鉴别应用价值高,尤其是ADC值对良恶性病灶的鉴别意义较大.     

MR imaging of multiple sclerosis

Owing to its ability to depict the pathologic features of multiple sclerosis (MS) in exquisite detail, conventional magnetic resonance (MR) imaging has become an established tool in the diagnosis of this disease and in monitoring its evolution. MR imaging has been formally included in the diagnostic work-up of patients who present with a clinically isolated syndrome suggestive of MS, and ad hoc diagnostic criteria have been proposed and are updated on a regular basis. In patients with established MS and in those participating in treatment trials, examinations performed with conventional MR pulse sequences provide objective measures to monitor disease activity and progression; however, they have a limited prognostic role. This has driven the application of newer MR imaging technologies, including higher-field-strength MR units, to estimate overall MS burden and mechanisms of recovery in patients at different stages of the disease. These techniques have allowed in vivo assessment of the heterogeneity of MS pathologic features in focal lesions and in normal-appearing tissues. More recently, some of the finer details of MS, including macrophage infiltration and abnormal iron deposition, have become quantifiable with MR imaging. The utility of these modern MR techniques in clinical trial monitoring and in the assessment of the individual patient's response to treatment still need to be evaluated.     

Diagnosis of breast tumors by contrast-enhanced MR imaging: comparison between the diagnostic performance of dynamic enhancement patterns and morphologic features

PURPOSE: To compare the diagnostic performance of breast lesions by the enhancement patterns and morphologic criteria on magnetic resonance imaging (MRI). MATERIALS AND METHODS: Both T1-weighted 3D gradient-echo sequences with high temporal resolution and high-spatial-resolution MRI were performed on 190 patients with a total of 204 enhancing lesions (144 malignant and 60 benign). The enhancement patterns and morphologic features of each mass and nonmass lesion were analyzed, and the diagnostic performance was compared. RESULTS: The sensitivity and specificity of the morphologic criteria were statistically significantly higher than those of the enhancement patterns (sensitivity: P = 0.0012, specificity: P = 0.0003), and the A(z) values for the three observers were 0.900, 0.919, and 0.900. The diagnostic accuracy of the morphologic criteria for both types of lesions was superior, and the differences were statistically significant (mass: P = 0.0001, nonmass: P = 0.0389). CONCLUSION: The analysis of the morphologic features of enhancing breast lesions alone showed higher diagnostic performance; therefore, signal intensity (SI) time-course data may not be needed to diagnose malignant breast lesions.     

Cine cerebrospinal fluid imaging in multiple sclerosis

Purpose:

To investigate cerebrospinal fluid (CSF) dynamics in the aqueduct of Sylvius in multiple sclerosis (MS) patients and healthy controls (HC) using cine phase contrast imaging.

Materials and Methods:

In all, 67 MS patients (48 relapsing‐remitting [RR] and 19 secondary‐progressive [SP]), nine patients with clinically isolated syndrome (CIS), and 35 age‐ and sex‐matched HC were examined. CSF flow and velocity measures were quantified using a semiautomated method and compared with clinical and magnetic resonance imaging (MRI) disease outcomes.

Results:

Significantly decreased CSF net flow was detected in MS patients compared to HC (?3.7 vs. ?7.1 μL/beat, P = 0.005). There was a trend for increased net positive flow between SP, RR, and CIS patients. Altered CSF flow and velocity measures were associated with more severe T1 and T2 lesion volumes, lateral and fourth ventricular volumes, and third ventricular width in MS and CIS patients (P < 0.01 for all). In CIS patients, conversion to clinically definite MS in the following year was related to decreased CSF net flow (P = 0.007). There was a trend between increased annual relapse rate and altered CSF flow/velocity measures in RRMS patients (P < 0.05).

Conclusion:

CSF flow dynamics are altered in MS patients. More severe clinical and MRI outcomes in RRMS and CIS patients relate to altered CSF flow and velocity measures. J. Magn. Reson. Imaging 2012;36:825–834. © 2012 Wiley Periodicals, Inc.

     

Improved in vivo detection of cortical lesions in multiple sclerosis using double inversion recovery MR imaging at 3 Tesla

Objective

To investigate the impact of a higher magnetic field strength of 3 Tesla (T) on the detection rate of cortical lesions in multiple sclerosis (MS) patients, in particular using a dedicated double inversion recovery (DIR) pulse sequence.

Methods

Thirty-four patients with clinically isolated syndromes or definite MS were included. All patients underwent magnetic resonance imaging (MRI) at 1.5 T and 3 T, including T2-weighted turbo spin echo (TSE), fluid-attenuated inversion recovery (FLAIR) and DIR sequences. All images were analysed for focal lesions categorised according to their anatomical location.

Results

The total number of detected lesions was higher at 3 T across all pulse sequences. We observed significantly higher numbers of lesions involving the cortex at 3 T using a DIR sequence. DIR at 3 T showed 192% more pure intracortical (p?<?0.001) and 30% more mixed grey matter-white matter lesions (p?=?0.008). No significant increase in cortical lesions could be detected on the FLAIR and T2-weighted images. Using the T2-weighted and FLAIR sequences, significantly more lesions could be detected at 3 T in the infratentorial, periventricular and juxtacortical white matter.

Conclusion

DIR brain MR imaging at 3 T substantially improves the sensitivity of the detection of cortical lesions compared with the standard magnetic field strength of 1.5 T.     

Magnetic resonance imaging features of papillary breast lesions

PurposeThis study was aimed to assess the role of magnetic resonance imaging (MRI) in the evaluation of the papillary lesions of the breast and their morphological relationship with the mammary ducts. The potential diagnostic contributory role of ductal oriented protocols to conventional dynamic magnetic resonance examination was also explored.Materials and methodsRetrospective data were collected from 46 patients who had been diagnosed with papillary breast lesions and undergone magnetic resonance examination.The presence of dilated ducts and their morphological relation with the lesion were recorded. Lesions were classified as follows: papilloma, papillomatosis and malignant papillary lesion. Statistical difference between groups was studied for each morphological and dynamic lesion characteristic.ResultsDilated ducts and characteristics of intraductal material can be identified by magnetic resonance imaging. Certain MRI findings such as a mass with crescentic peripheral fluid or focal intraductal mass on T2 weighted images may suggest the presence of an intraductal/papillary lesion. In this respect, non-fatsat T2 weighted images appear particularly useful. There was a significant difference between papilloma and papillomatosis with regard to segmental and heterogeneous contrast enhancement (p < 0.05 for both comparisons). In addition, there was a significant difference between papillomas and carcinomas with regard to homogenous, heterogeneous and segmental contrast enhancement (p < 0.05 for all). On the other hand, papillomatosis and carcinoma did not differ significantly in terms of any of the morphological or dynamical MR criteria compared.ConclusionPapillary lesions can be detected by MRI. Despite some overlaps in MRI findings between carcinoma, papilloma and papillomatosis, MRI may help differentiate these lesions. Major benefit of retroareolar imaging appears to arise from its ability to demonstrate ductal relation and extension of contrast enhanced regions.