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Objective To investigate the MRI features of pleomorphic xanthoastrocytoma (PXA).Methods 1 5 pathologically confirmed PXA cases were analyzed retrospectively.Clinical history and imaging features including location,size,shape,signal intensi-ty,enhancement and surrounding changes of those lesions were analyzed.Results All 1 5 cases were supratentorial and solitary le-sions,of which 9 lesions located in temporal lobe(60%).14 lesions contacted with the leptomeninges,and 1 lesion contacted with lat-eral ventricle wall.All lesions were solid-cystic,with different proportion of solid/cystic components.8 large lesions were predomi-nantly cystic(53.3%),3 small lesions were predominantly solid(20%),and 4 lesions had roughly equal cystic and solid proportions (26.7%).Solid components showed iso-intense or mild hypo-intense on T1 WI,iso-intense or mild hyper-intense on T2 WI,and signif-icant enhancement with contrast.Cyst fluid showed slightly hyper-intense in some cases.Cyst wall or septa enhancement was seen in 7 cases,and leptomeningeal enhancement was seen in 8 cases.Conclusion The MRI features of PXA are the characteristic of suprat-entorial solid-cystic lesions commonly seen in temporal lobe and contacting with leptomeninges.The typical features include “cyst with mural nodule”and “multiple cysts with irregular eccentric nodule”with significant enhancement of solid component and some cyst wall.MRI features of PXA is valuable in diagnosis and differential diagnosis of PXA.
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OBJECTIVE@#To evaluate signal intensity-time (SI-Time) curve and quantitative dynamic contrast-enhanced 3.0T magnetic resonance imaging in diagnosis and differentiating neoplasm of uterus. @*METHODS@#A total of 42 cases of uterine neoplasm (20 were malignant and 22 were benign) were evaluated in our study. All cases received dynamic contrast-enhanced scanning on 3.0T MRI. The raw data was processed by Siemens Tissue 4D software and the SI-Time curve was obtained and analyzed. Pharmacokinetic modeling of Tofts with a modeled vascular input function was used for calculating volume parameters: volume transfer constant (Ktrans), reverse volume transfer constant (Kep), the extravascular extracellular space volume per unit volume of tissue (Ve). The correlation of these parameters at each groups were investigated. The SI-Time curve and the data of perfusion parameters between the 2 groups were compared by T test. @*RESULTS@#Among 20 malignant tumors, 12 were cervical carcinoma and 8 were endometrial cancer. Among the benign tumors, 13 were leiomyomas, 3 were endometrial polyp, 3 were endometrial hyperplasia, and 3 were adenomyosis. 59.1% cases of benign tumors belong to Type I curve and 65% cases of malignant tumors belong to Type II curve. There was significant difference in SI-Time curve between benign and malignant tumors (P=0.011). If Type I curve was used as diagnostic criteria for benign tumors, and Type II and III curve were for malignant tumors, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value were 90.0%, 59.1%, 66.7%, and 86.7%, respectively. Ve was 0.477 ± 0.143 in malignant and 0.614 ± 0.146 in control group with significant difference (P=0.004). Ve was 0.477 ± 0.143 in malignant and 0.589 0.176 in benign group with significant difference (P=0.004). Ktrans was (0.178 ± 0.067) min⁻¹ in malignant and (0.263 ± 0.111) min⁻¹ in control group with significant difference (P=0.003). Ktrans was (0.182 ± 0.096) min⁻¹ in benign and (0.263 ± 0.111) min⁻¹ in control group with significant difference (P=0.011). @*CONCLUSION@#The type of SI-Time curve and perfusion parameters were important for differentiating benign and malignant uterine tumors in dynamic enhanced MRI. These parameters provide a supplement for conventional morphological MR diagnosis.
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Female , Humans , Contrast Media , Magnetic Resonance Imaging , Sensitivity and Specificity , Uterine Neoplasms , Diagnosis , Uterus , PathologyABSTRACT
Objective To analyses the CT characteristics of primary malignant ovarian tumors and metastatic ovarian carcinoma and its diagnosis and differential diagnosis.Methods CT findings in 31 patients with pathologically-proved malignant ovarian tumors,encountered during 1999-04~2003-11 were retrospectively analyzed.The observation of the lesion was focused on the following aspects:location,internal density,septa,wall,intra-cystic and extra-cystic vegetation,the composition of the soft tissue,ascites,peritoneum,mental implantation and metastatic lymphadenopathy.The characteristic of each in both primary malignant ovarian tumor and metastatic ovarian tumor were compared.Results Among the 24 primary malignant ovarian tumors,13 patients had lesions in both sides of ovary,type Ⅱa:n=3,Type Ⅱb:n=11,Type Ⅱc:n=7,Type Ⅲ:n=3.Among the metastatic ovarian carcinomas,Type Ⅱa:n=6,Type Ⅱc:n=1.Conclusion Type Ⅱb and Ⅱc are commonly seen in primary malignant ovarian tumors.Type Ⅱa is always seen in metastatic ovarian carcinoma.The metastatic tumors often happen in the right peritoneum,epiploon,and liver."arborization and silk screen likely"are the characteristic representation of the metastatic ovarian carcinoma.