单纯乳腺导管内癌的3．0T MR影像表现（附97例）分析

目的 分析乳腺导管内癌（DCIS）的3.0T MRI影像学特点,探讨磁共振扩散加权成像（DWI）对DCIS的诊断价值.方法 回顾性分析单纯DCIS 97例,依据乳腺影像报告和数据系统（BI-RADS-MRI）,记录DCIS的形态学、病变强化至120s时的峰值（％）、时间-信号曲线（TIC曲线）及DWI特征.结果 97例共检出100个DCIS病灶.其中点状/斑点状病灶3个（3％）,非肿块样强化病灶83个（83％）,肿块型病灶14个（14％）.非肿块样强化病灶中,以段状（48个）和局灶区域状（22个）分布最常见,43.4％呈集簇状强化.所有病灶平均120s强化峰值为172％±54％.TIC曲线以平台型（Ⅱ型）最多见.87个病灶DWI扩散受限,肿块型与非肿块型病变平均ADC值分别为（1.07±0.22）×10-3mm2/s及（1.23±0.15）×10-3 mm2/s.结论 DCIS的典型形态为段样分布的集簇状强化,TIC常表现为Ⅱ型.DWI可提高DCIS检出的敏感性.     

Nodular fasciitis: correlation of MRI findings and histopathology

OBJECTIVE: To compare the histopathology of nodular fasciitis (NF) with the magnetic resonance imaging (MRI) findings in order to evaluate the basis of the MR signal characteristics. DESIGN AND PATIENTS: Ten patients with NF, nine females and 1 male, with an age ranging from 13 to 58 years (mean 26.8 years) were studied. MRI findings, available in all 10 patients, were compared with the histopathology in nine patients, and an area-to-area comparative study of the whole specimen section histopathology and MRI was performed in two patients. RESULTS: On the basis of an excisional biopsy or resection specimen, the nine lesions were classified into myxoid ( n=4), cellular ( n=3) and fibrous ( n=2) subtypes. Four myxoid lesions with a subcutaneous location showed a homogeneous SI comparable with muscle on T1-weighted images, high SI on T2-weighted images, and had homogeneous enhancement. One cellular lesion presented with homogeneous, slightly higher SI than muscle on T1-weighted images and inhomogeneous, high SI on T2-weighted images. Alcian blue stain of the whole specimen section revealed the lesion had two parts corresponding to different enhancement patterns on MRI. The blue-stained myxoid part showed markedly diffuse enhancement, while the non-stained cystic space had only peripheral enhancement. Two other cellular lesions had the same appearance on both T1- and T2-weighted images and showed inhomogeneous, diffuse enhancement. One fibrous subtype lesion presented with inhomogeneous, overall slightly higher SI than muscle on T1-weighted images, lower SI at the periphery and high SI in the center on STIR images and only peripheral enhancement. Microscopy and CD-31 staining of the lesion showed more extracellular matrix, with poor vascularity in the center and more collagenous matrix with higher vascularity at the periphery. CONCLUSION: Although similar findings were found in some lesions, the large histologic variability of NF hampers the definition of a prototype of NF on MRI. However, the MRI appearance of the myxoid subtype is rather characteristic. Histologic findings reflect the different SI characteristics and enhancement pattern on MRI.     

Lymphadenopathy at the medial epitrochlear region in cat-scratch disease

Our objective was to describe the imaging features of lymphadenopathy at the medial epitrochlear region as frequently seen in cat-scratch disease (CSD) and to compare these features with those seen in non-CSD. Ten patients (four males and six females) presented with a subcutaneous soft tissue mass at the medial epitrochlear region. Three patients were younger than 15 years. Magnetic resonance imaging was performed in all patients. All lesions turned out to be regional lymphadenopathy instead of soft tissue neoplasm. They were caused by benign disorders in eight cases, including seven CSD and one other infection, and in two cases by metastatic disease. All lesions, except for three benign ones, were solitary. On MRI, high signal intensity (SI) strands in the surrounding soft tissue on T2-weighted images (WI) were present in all cases. Three cases of CSD showed homogeneous SI on both T1- and T2WI. After contrast administration, a moderate, homogeneous enhancement was seen. The other seven lesions, except for one metastasis, had both solid and liquid components. Liquid components showed high SI on T2WI without enhancement, whereas solid components had intermediate SI on T2WI and marked enhancement after contrast administration. Pathological findings in seven patients, including four with CSD, supported the tentative diagnosis made on MRI. One of two patients with CSD had positive serological test. Cat-scratch disease is a major cause of a soft tissue swelling at the medial epitrochlear region. Identification of lymphadenopathy and its presentation on MRI may be helpful in eliciting an animal-scratch history and achieving diagnostic and therapeutic aims in patients without primary cancer. Electronic Publication     

Diagnostic usefulness of segmental and linear enhancement in dynamic breast MRI

The aim of this study was the evaluation of the diagnostic usefulness of ductal or segmental enhancement in dynamic breast MRI. Segmental and ductal enhancement have been established as the breast MRI hallmarks of intraductal breast cancer (DCIS); however, the positive predictive value of this imaging finding is still unknown. In our study, we analysed the overall prevalence of a segmental or a linear enhancement pattern on breast MRI for an unselected cohort of patients. The aim was to evaluate the diagnostic usefulness of segmental or linear enhancement. Second, we asked whether biopsy was necessary also in the absence of mammographic findings suggestive of DCIS. Prospective, consecutive evaluation of 1,003 patients undergoing bilateral dynamic breast MRI. Studies were interpreted by two experienced breast radiologists. A diagnostic or screening two-view mammogram was available for all patients. Biopsy or short-term breast MRI follow-up was recommended for patients showing a segmental or a linear enhancement pattern on breast MRI. The patients final diagnoses were established by imaging guided excisional or core biopsy or by clinical plus conventional imaging follow-up for a period of 2 years. The prevalence of segmental or linear enhancement was determined for patients with a final diagnosis of benign breast disease compared with those with a diagnosis of breast cancer. One hundred twenty patients had invasive breast cancer, 24 patients had DCIS and 859 patients had unsuspicious breast MRI or benign breast disease. A segmental or a linear enhancement pattern was found for 50/1,003 (5%) patients (17 DCIS, 33 benign breast diseases). Accordingly, the positive predictive value of segmental and linear enhancement is 34% (17/50); the specificity of this criterion is 96% (826/859). For 4/24 (17%) patients, DCIS was visible as segmental or linear enhancement on dynamic breast MRI, whereas no abnormalities were visible on the corresponding mammogram. The overall prevalence of a ductal or a segmental enhancement pattern on breast MRI is low. But this finding has a high specificity and a moderate positive predictive value for intraductal neoplastic changes. We conclude that if segmental or linear enhancement is identified on breast MRI further work-up is necessary. We recommend either direct MR-guided vacuum-assisted core biopsy or short-term follow-up breast MRI within 3 months. If ductal enhancement then persists, MR-guided biopsy should be recommended even in the absence of mammographically visible signs of DCISThis revised version was published online in May 2005 with corrections to Figs. 3c, 4c and 5c.     

The role of diffusion-weighted imaging and the apparent diffusion coefficient (ADC) values for breast tumors.

OBJECTIVE: We wanted to evaluate the role of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) for detecting breast tumors, as compared with the T1- and T2-weighted images. MATERIALS AND METHODS: Forty-one female patients underwent breast MRI, and this included the T1-, T2-, DWI and dynamic contrast-enhanced images. Sixty-five enhancing lesions were detected on the dynamic contrast-enhanced images and we used this as a reference image for detecting tumor. Fifty-six breast lesions were detected on DWI and the histological diagnoses were as follows: 43 invasive ductal carcinomas, one mucinous carcinoma, one mixed infiltrative and mucinous carcinoma, seven ductal carcinomas in situ (DCIS), and four benign tumors. First, we compared the detectability of breast lesions on DWI with that of the T1- and T2-weighted images. We then compared the ADCs of the malignant and benign breast lesions to the ADCs of the normal fibroglandular tissue. RESULTS: Fifty-six lesions were detected via DWI (detectability of 86.2%). The detectabilities of breast lesions on the T1- and T2-weighted imaging were 61.5% (40/65) and 75.4% (49/65), respectively. The mean ADCs of the invasive ductal carcinoma (0.89+/-0.18 x 10(-3)mm(2)/second) and DCIS (1.17+/-0.18 x 10(-3)mm(2)/ second) are significantly lower than those of the benign lesions (1.41+/-0.56 x 10(-3)mm(2)/second) and the normal fibroglandular tissue (1.51+/-0.29 x 10(-3)mm(2)/ second). CONCLUSION: DWI has a high sensitivity for detecting breast tumors, and especially for detecting malignant breast tumors. DWI was an effective imaging technique for detecting breast lesions, as compared to using the T1- and T2-weighted images.     

Mangafodipir trisodium‐enhanced MRI for the detection and characterization of focal hepatic lesions: Is delayed imaging useful?

PURPOSE: To investigate the usefulness of early and delayed hepatic MRI after mangafodipir trisodium (Mn-DPDP) administration for the detection and characterization of focal hepatic lesions. MATERIALS AND METHODS: Forty-five patients (31 males and 14 females, mean age = 61 years) with a total of 113 hepatic lesions (mean size = 3.5 cm) were included in this study (15 with hepatocellular carcinoma (HCC, N = 35), 20 with hepatic metastasis (N = 63), five with hemangioma (N = 10), three with cholangiocarcinoma (CC, N = 3), and two with liver abscess (N = 2)). T1-weighted gradient-echo MR images were obtained before and after Mn-DPDP administration, with a mean 18-hour delayed imaging. A qualitative analysis (including the size and signal intensity (SI)) and quantitative analysis (including enhancement and lesion-liver contrast-to-noise ratio (CNR)) were performed on pre- and postcontrast early and delayed MR images. RESULTS: Compared to postcontrast early imaging, 17 (48.6%) of 35 HCCs showed higher SI, 16 (45.7%) showed no SI change, and two (5.7%) showed lower SI on delayed imaging. All 63 metastases, 10 hemangiomas, three CCs, and two abscesses showed no SI change. On delayed imaging, ring enhancement was noted in 53 metastases (84.1%), three hemangiomas (30.0%), and one abscess (50.0%), but was not seen in HCCs or CCs. Eight metastases (12.7%) also showed ring enhancement on postcontrast early imaging. No newly detected hepatic lesions were revealed on postcontrast delayed MR images compared to postcontrast early images. Regarding CNR, the HCCs showed a significant increase in CNR from postcontrast early to delayed images after administration of Mn-DPDP (P < 0.01). However, none of the metastases, hemangiomas, CCs, and abscesses showed a significant increase of CNR from postcontrast early to delayed images. CONCLUSION: Postcontrast delayed MR images after Mn-DPDP administration were helpful in distinguishing hepatocellular from nonhepatocellular lesions, but were not useful for lesion detection and had limited utility for lesion characterization, since benign and malignant hepatic lesions looked the same.     

MR imaging of hepatocellular carcinoma: relationship between lesion size and imaging findings, including signal intensity and dynamic enhancement patterns

PURPOSE: To assess the relationship between lesion size and MR imaging findings of pathologically-proven hepatocellular carcinoma (HCC). MATERIALS AND METHODS: In a retrospective, single-center study, 37 consecutive patients were identified between 1999 and 2005 that underwent preoperative MRI and surgical resection of HCC. A total of 47 lesions (mean size = 6.85 cm, range = 1-25 cm) were assessed for signal intensity (SI), enhancement patterns, and secondary morphologic features. Interobserver rating, percentage enhancement, and contrast-to-noise-ratio (CNR) were determined. Lesions were assessed for combinations of typical MRI features. Regression analysis was used to assess relations between MRI findings and tumor size. RESULTS: On fat-suppressed T2-weighted (T2w) fast-spin-echo, smaller lesions had lower SI compared to larger lesions (P < 0.05). In the arterial phase, smaller lesions showed significantly higher percentage enhancement compared to larger lesions (P < 0.05). In the delayed phase, smaller lesions showed less pronounced washout (P < 0.05). Heterogeneity of the lesions, including fatty infiltration, internal nodules, or mosaic pattern, was observed significantly more frequently in larger lesions (P < 0.001). The classic combination of high T2w signal, strong arterial enhancement, and delayed phase washout was present in 23 of 44 lesions (52%). CONCLUSION: Smaller HCC often showed lower SI on T2w, more intense arterial enhancement, and less pronounced delayed washout compared to larger HCC.     

Cluster analysis of signal-intensity time course in dynamic breast MRI: does unsupervised vector quantization help to evaluate small mammographic lesions?

We examined whether neural network clustering could support the characterization of diagnostically challenging breast lesions in dynamic magnetic resonance imaging (MRI). We examined 88 patients with 92 breast lesions (51 malignant, 41 benign). Lesions were detected by mammography and classified Breast Imaging and Reporting Data System (BIRADS) III (median diameter 14 mm). MRI was performed with a dynamic T1-weighted gradient echo sequence (one precontrast and five postcontrast series). Lesions with an initial contrast enhancement >or=50% were selected with semiautomatic segmentation. For conventional analysis, we calculated the mean initial signal increase and postinitial course of all voxels included in a lesion. Secondly, all voxels within the lesions were divided into four clusters using minimal-free-energy vector quantization (VQ). With conventional analysis, maximum accuracy in detecting breast cancer was 71%. With VQ, a maximum accuracy of 75% was observed. The slight improvement using VQ was mainly achieved by an increase of sensitivity, especially in invasive lobular carcinoma and ductal carcinoma in situ (DCIS). For lesion size, a high correlation between different observers was found (R(2) = 0.98). VQ slightly improved the discrimination between malignant and benign indeterminate lesions (BIRADS III) in comparison with a standard evaluation method.     

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.     

MR findings of Rosai-Dorfman disease in sellar and suprasellar region

Background

Rosai–Dorfman disease (RDD) in sellar/suprasellar region is a rare intracranial disorder. The diagnostic evaluation of this condition using magnetic resonance imaging (MRI) has seldom been described previously. The purpose of our study was to describe MRI characteristics of sellar/suprasellar region RDD.

Methods

Five patients with proved sellar/suprasellar region RDD from May 2005 to March 2010 were retrospectively reviewed. All the patients had undergone magnetic resonance scanning. The number, location, signal intensity (SI), and enhancement pattern of the lesions on MRI were retrospectively evaluated.

Results

Pathological diagnosis of RDD was achieved in all 5 cases including 4 by surgery and 1 by biopsy. The most common presenting symptoms were headache (n = 4) and blurred vision (n = 3). On MRI, isolated suprasellar lesion was found in 2 cases. Suprasellar lesion combined with intrasellar, dural, intra-axial and orbital lesions was found in 3 cases. All lesions showed homogeneous isointense SI on T1-weighted images and hypointense to isointense SI on T2-weighted images except one lesion in the midbrain with slight hyperintense SI on T2-weighted images. All lesions showed homogeneous enhancement.

Conclusion

Homogenously enhancing sellar/suprasellar masses of hypointense to isointense SI on T2-weighted images are suggestive of RDD, and central hypointensity on T2-weighted images may be a specific finding. Intra-axial and extra-axial involvements may coexist with sellar/suprasellar region RDD. Although radiological findings can provide some evidence for this rare entity, differential diagnosis is still needed.     

Invited. Predictability of the size of laser-induced lesions in T1-weighted MR images obtained during interstitial laser-induced thermotherapy of benign prostatic hyperplasia

The purpose of this study was to predict diameters of lesions induced by laser-induced thermotherapy (LITT) of benign prostatic hyperplasia (BPH) from MRI signal/tissue temperature correlations during on-line monitoring with a temperature-sensitive fast low-angle shot (FLASH) sequence. Twenty LITT procedures with Nd:YAG (1,064 nm) and diode (830 nm) lasers were monitored on line with a T1-weighted FLASH sequence at 1.5 Tesla. Interstitial prostate temperature (T) was measured on line in 10 LITT procedures and laser energy deposition in 12. Slopes of linear regression curves for signal intensity (SI) over T were applied to determine SI at 60°C to estimate diameters of intraprostatic LITT lesions. Diameters of unperfused LITT lesion cores in contrast-enhanced T1-weighted images served as gold standards. Linear regression curves with an average slope of ?.54% SI/°C were obtained in 17 LITT procedures. Correlation coefficients were r = .92?.95 for SI/T and SI/energy deposition. Baseline variation of SI at body temperature was ±3.9%, corresponding to ±7°C. Prediction of size (13 lesions) from on-line FLASH imaging was correct in 10 of 13, whereas 3 lesions were overestimated. Prediction of LITT lesion diameters from on-line MRI monitoring is possible with a temperature-sensitive FLASH sequence in the prostate. Accuracy may suffice to assign target regions of interest to tissue locations to be protected from coagulation.     

MR重T2W首次通过灌注成像鉴别乳腺良恶性肿瘤的价值初探

目的　评价在同 1次检查中T1W动态增强成像之后进行重T2 W (T 2 W )首次通过灌注成像的可行性 ,以及后者在鉴别乳腺良恶性肿瘤方面的诊断价值。方法　 2 9例乳腺病患者在T1W动态增强后进一步行病灶局部的T 2 W首次通过灌注成像 ,分别根据病灶T1W动态增强的早期强化程度和T 2 W首次通过灌注成像的早期信号丢失程度判定病灶的良恶性 ,计算其敏感度、特异度 ,以进行两方法间的比较。结果　应用T1W动态增强成像序列 ,良、恶性病变的信号强度增加率之间差异有显著性意义 (t=2 5 6 3,P =0 0 16 ) ,但两者的早期增强程度范围有很大的重叠 ;早期增强率诊断的敏感度为 94 % ,特异度仅为 2 5 %。应用T 2 W首次通过灌注成像序列 ,良、恶性病变之间的T2 信号强度丢失程度差异有非常显著性意义 (t=4 777,P <0 0 0 1) ,良、恶性病变的早期信号丢失率之间重叠很少 ;早期信号丢失率诊断的敏感度为 88% ,特异度为 75 %。结论　T 2 W首次通过灌注成像在鉴别良恶性乳腺肿瘤方面具有较高特异度 ;在同一患者中 ,T 2 W首次通过灌注成像结合T1W动态增强成像检查是可行的 ,可以提高乳腺MR成像的诊断准确性。     

Value of opposed-phase gradient-echo technique in distinguishing between benign and malignant vertebral lesions

Our objective was to evaluate the possible role of opposed-phase gradient-echo (GRE) sequence in predicting the nature of vertebral lesions supposing that in the case of malignancy fat is completely replaced while in the case of benign lesion fat is still present. Eighty-six patients with vertebral lesions underwent MR examination at 0.5 T. The MR protocol included a T1-weighted spin-echo (SE) and an opposed-phase GRE using the same parameters (TR=280-320 ms, flip angle=90 degrees, slice thickness=3.5-4 mm, matrix=256x160-192, field of view=34-36 cm, no. of excitations=2-4) except for TE (10 ms in SE vs 7 ms in GRE) to obtain opposed-phased images. Qualitative (nature of lesion, detectability, degree of signal intensity (SI), marrow pattern) and quantitative (SI on opposed-phase GRE minus SI on T1-weighted SE minus SI ratio=SI on out-of-phase GRE images divided by SI on T1-weighted SE images) analysis were performed. The SI ratio values were analysed using Mann-Whitney rank-sum test and receiver operating characteristics (ROC) curve. Lesions resulted to be malignant in 45 and benign in 41 patients (23 biopsies, 20 MR follow-ups, 43 clinical and other imaging follow-ups). Based on visual inspection of opposed-phased images, visual SI was evaluated high in 38 (34 malignant, 34 benign), mild in 28 (9 malignant, 19 benign) and low in 20 (2 malignant, 18 benign) patients. Based on region-of-interest measurements, SI ratio values range was 0.36-6.2 (mean value=1.68+/-0.82) for malignant and 0.07-1.54 (mean value=0.77+/-0.44) for benign lesions. A cut-off value of 1.2 gave a sensitivity, specificity, accuracy, negative predictive value and positive predictive value, respectively, of 88.8, 80.49, 84.88, 86.4 and 83.33%. The ROC analysis of the SI ratio showed an area under ROC curve of 0.92 and a statistically significant difference between the two groups of lesions was observed ( p<0.01). The GRE opposed-phase sequence can help to predict the nature of a vertebral lesion. This fast and widely available technique together with morphological criteria can improve the accuracy of MRI.     

Malignant lesions of the liver with high signal intensity on T1-Weighted MR images

Our purpose was to identify the histologic types of malignant liver lesions with high signal intensity (SI) on T1-weighted images and to describe the MR imaging features. Thirteen patients with malignant liver lesions high in SI on T1-weighted images were studied with a 1.5-T MR imager using pre- and serial postcontrast spoiled gradient-echo (SGE) sequences (all patients), T2-weighted fat-suppressed spin-echo sequences (all patients), precontrast T1-weighted fat-suppressed spin-echo sequences (five studies in five patients), and precontrast out-of-phase SGE sequences (seven studies in six patients). Images were reviewed retrospectively to determine number of lesions; lesion size; SI of lesions on T1-weighted, T2-weighted, and fat-attenuated T1-weighted images; distribution of high SI in lesions on T1-weighted images; and tumor enhancement pattern. Seven patients had multiple tumors high in SI on T1-weighted images and six patients had solitary tumors. Seventy-two lesions were less than 1.5 cm in diameter and 35 lesions were more than 1.5 cm in diameter. Nine patients had solid malignant lesions and four patients had cystic malignant lesions. All tumors more than 1.5 cm in diameter were heterogeneously high in SI on T1-weighted images, and all tumors less than 1.5 cm were completely homogeneous or homogeneous with a small central hypointense focus. All tumors were more conspicuous on T1-weighted fat-attenuated images, both on excitation spoiled fat-suppressed spin-echo or on out-of-phase SGE images with the exception of one fat-containing hepatocellular carcinoma (HCC). In one patient with melanoma metastases and one patient with multiple myeloma nodules, appreciably more lesions were detected on out-of-phase SGE images. Causes of hyperintensity were considered to be either fat, melanin, central hemorrhage, or high protein content, all of which may be seen in a variety of tumors. Fat-attenuation techniques are helpful in the detection of these lesions.     

Characteristics of ductal carcinoma in situ in magnetic resonance imaging

PURPOSE: The aim of this study was to evaluate typical dynamic and morphological characteristics of ductal carcinoma in situ (DCIS) in magnetic resonance imaging (MRI). An optimized diagnosis of DCIS is considered to be valuable for radiologists and clinicians, especially for early and successful treatment planning. MATERIALS AND METHODS: Magnetic resonance examinations of 74 patients with pure DCIS were evaluated. Categories were established for signal increase (C1=the same enhancement as glandular tissue; C2=slow and continuous; C3=strong initial and slow further increase; C4=strong initial increase and plateau phenomenon; and C5=strong initial increase followed by a washout phenomenon) and morphological findings (M0=no pattern observed; M1=linear or linear-branched; M2=segmental dotted or granular; M3=segmental homogenous; and M4=focal spotlike). All cases were associated with histopathological results. RESULTS: Regarding the 74 DCIS lesions, 37 (50%) showed a signal increase typical of malignancy (C4 and C5). Among all cases, 33.3% of G1 lesions, 68.4% of G2 lesions, and 55.5% of G3 lesions presented a C4 or C5 enhancement. Furthermore, 55.4% (n=41) showed a segmental dotted enhancement (M2), whereas 17.6% showed a focal spotlike enhancement (M4). The morphological features of the other lesions were as follows: 12.2% homogeneous (M3) and 4.0% linear (M1). In 8 cases (10.8%), no significant pattern was observed (M0). Combining dynamic and morphological characteristics, 68.9% presented an appearance comparable with the appearance of invasive breast cancer in MRI. CONCLUSIONS: Ductal CIS lesions show typical morphological and kinetic, but heterogeneous, characteristics in MRI, comparable with the histopathological variety of the disease. For detecting pure DCIS cases early and precisely, a combination of dynamic and morphological criteria seems to be important.     

Diagnostic value of MRI in tuberculous meningitis

In this study 15 patients with clinical findings and positive cerebrospinal fluid analyses for tuberculous meningitis were evaluated with magnetic resonance imaging (MRI). Tuberculous meningitis was diagnosed in 11 cases when thick meningeal enhancement was present after intravenous injection of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) in T1-weighted images. Intra-axial tuberculomas were present in 8 patients, 2 of whom had intra-axial tuberculomas without MRI evidence of meningitis. Tuberculomas showed ring or nodular enhancement in postcontrast T1-weighted images, but the most significant MR feature of intraparenchymal tuberculomas was the hypointense appearance of the lesions on T2-weighted images.Correspondence to: C. Tayfun     

脉络膜血管瘤的MRI表现及动态增强研究

目的 探讨眼脉络膜血管瘤的常规及动态增强MRI表现.方法 回顾性分析30例(31只眼共32个病灶)经临床、眼底相及荧光血管造影确诊的脉络膜血管瘤的MRI资料,其中行平扫和常规增强扫描30例,行动态增强扫描26例,观察各个序列MRI表现,计算动态增强曲线参数.结果 32个脉络膜血管瘤病灶中,位于视乳头颞侧26个病灶,呈梭形28个病灶;与玻璃体信号相比,T1WI呈等信号23个病灶,T2研呈等信号31个病灶;增强后明显强化32个病灶,强化均匀31个病灶,不均匀1个病灶,伴视网膜脱离18只眼;动态增强扫描出现填充征12个病灶,时间-信号曲线呈速升缓降型28个病灶,峰值时问为(91.00±25.27)s,上升斜率为3.03±1.13,流出率中位数为17.06%,强化率为2.87±0.79.结论 脉络膜血管瘤MRI现病灶形态、信号及动态增强具有一定特点,能为临床诊断和治疗方案制定提供重要信息.     

Unusual malignant tumors of the breast: MRI features and pathologic correlation

Unusual malignant breast tumors are well-differentiated subtypes of invasive ductal carcinoma, including mucinous, tubular, medullary and papillary carcinomas, and account for about 10% of malignant breast tumors. They are increasingly being encountered during magnetic resonance imaging (MRI) examinations of the breast. Therefore, breast radiologists should be aware of their appearance on MRI.This review provides an overview of MRI characteristics of a range of unusual tumors (mucinous carcinoma, medullary carcinoma, tubular carcinoma, intraductal papillary carcinoma, intracystic papillary carcinoma and invasive papillary carcinoma), highlighting specific clues for diagnosis and correlating MRI and pathologic features. Many unusual breast tumors exhibit MRI features similar to those of benign or low suspicious lesions (oval shape, well-defined margins, high signal intensity on T2-weighted images, continuous increase kinetics, i.e. type I dynamic curve), leading to a possible misdiagnosis. Nevertheless, an understanding of pathologic features of these tumors, especially tissue content (mucinous, fibrous) and growth pattern, can help to define some specific clues for their diagnosis.     

MR imaging of intracranial tuberculomas

Eight patients with intracranial tuberculomas were studied with CT and magnetic resonance (MR) imaging. Large, ring enhancing, solid lesions on CT showed low intensity on T2-weighted images and intermediate intensity on T1-weighted images. Small lesions, with ring enhancement on CT, showed central bright signal on T2-weighted images with a peripheral low intensity rim surrounded by high intensity edema. The MR imaging features of the tuberculomas were found to be distinct from those of abscesses, metastases, and gliomas.