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Objective To characterize the features of Nasopharyngeal non-Hodgkin's lymphoma (NHL) on MR imaging and find the main points to differentiate it from the other nasopharyngeal tumors.Methods The MR images of 41 patients with pathologically and immunohistochemically proven nasopharyngeal NHLs were reviewed retrospectively. Images were assessed by the size, invasive extent,signal intensity of primary nasopharyngeal tumor, and the distribution of cervical lymphadenopethy. The difference of regional tissues invasion and cervical lymphadenopathy distribution between the patients with B-cell NHLs and the patients with T-cell or NK/T-cell NHLs were analyzed by Pearson's Chi-Square test or Fisher's exact test Results Of the 41 patients, 26 patients had mature B-cell lymphoma, two patients with mature T-cell Iymphoma, and thirteen patients showed Nature killer/T-cell lymphoma in nasopharynx. MRI revealed that NHLs of nasopharynx can be showed as thickening of nasopharyngeal mucosa and (or) lumps in nasopharynx, which were slightly hyper-intensity on T2-weighted images, and intermediate signal intensity (similar to muscle) on T1 -weighted images, with mild or moderated enhancement following contrast medium administration. Twenty four cases had symmetrical disease of all walls of nasopharynx, and 17 cases had unsymmetrical tumor. Of all cases, 5 cases had superficial ulcerations, 9 cases had exceed nasoharynx invasion spreads superficially along the mucosa, 23 cases had invasion of lingual and (or) palatine tonsils,20 cases showed invasion of parapharygeal muscles, 12 cases suffered from skull base bone infiltration,25 cases had retropaharyngeal lymphadenopathy, and 27 cases had cervical lymhadenopathy. Patient with nasopharyngeal Nature killer/T-cell lymphoma had a higher incidence of exceed nasopharynx invasion,parapharyngeal structures invasion, and superficial ulcerations (the cases were 8, 11, 4 in patient with T-cell or N K/T-cell lymphoma, and 4, 10, 1 in patients with B-cell lymphoma, respectively). Patients with nasopharyngeal B-cell lymphoma had a higher incidence of inasion of lingual and (or) palatine tonsils.Conclusions Nasopharyngeal NHL is a homogeneous tumor that tends to diffusely involve all walls of the nasopharynx and spread in an exophytic fashion to fill the airway, rather than infiltrating into the deep tissues. Different pathological types of nasopharyngeal NHLs have some different appearance on MRI between each other. A large tumor in nasopharynx that fills the nasopharynx cavity, with no or minimal invasion into deep structures, but with invasion extend down into the lingual and(or)palatine tonsils, may suggest the diagnosis of nasopharyneal NHL.
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Objective To study the imaging features of Kimura disease to improve diagnostic ability prior to surgery.Methods The clinical manifestations and CT and MR findings of 11 patients with histologically confirmed Kimura disease were retrospectively analyzed.All 11 tumors originated from (or involved)the parotid region in 7 cases, the maxillofacial region in 2 cases, the palate in one case and the groin in one case.Clinically, the lesions showed asymptomatic tumors with the mean clinical course over 2 years.The increase of cosinophilic granulocyte was found in all 11 cases.Results On CT and MRI,5 patients were single masses and others were muhi-nodular masses.The smallest lesion was 6 mm×3 mm,and the largest lesion was 60 mm × 34 mm.The lesions were almost ill-defined in the subcutaneous tissue,especially 10 locating underlying superficialfascia in head and neck.On CT,the lesions showed homogeneous hypodense to the muscle in 9 patients.The lesions appeared isointeuse signal or slightly hypointense on MR T1WI and slightly hyperinteuse on T2WI in 3 patients.All lesions revealed moderate or marked, and homogeneous or inhomngeneous enhancement.Regional lymph nodes (eight cases in the maxillofacial region and one in the groin) enlarged without necrosis and fusion, and with marked enhancement.Conclusion The clinical and imaging findings of Kimura disease have some characteristics, the diagnosis can be made combined with the laboratory examination.
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Objective To evaluate the value of MR spectroscopy (MRS) in the differential diagnosis between recurrence and radiation encephalopathy after radiotherapy for nasopharyngeal carcinoma (NPC). Methods Muhi-voxel proton MRS was performed on 50 patients with NPC, who were suspected of intracalvarium tumor recurrence or radiation encephalopathy after radiotherapy by conventional MRI,including 44 males and 6 females. Among the 50 patients, 26 cases were finally diagnosised as basicranial tumor recurrence and 24 cases as radiation encephalopathy by clinical and MRI follow-up. The following metabolites, such as Cho, NAA, Cr, lactate and lipid, were analyzed comparatively between basicranial tumor recurrence and radiation encephalopathy(RE), and between the lesions and the relative normal brain tissue. Wilcoxon's rank sum test was used to analyze the data. Results The median of Cho/Cr, Cho/NAA,LI/Cr in tumor recurrence group were 2. 22, 2. 13, and 1.77, respectively, and 1.40, 1.31, and 0. 57,respectively, in RE group. The difference of Cho/Cr, Cho/NAA, and LL/Cr between the two groups were statistically significant (P < 0. 01). Those in tumor recurrence group were higher than in RE group. The median of Cho, Cr, NAA in tumor recurrence group and in RE group were 3366. 00, 1023.00, 1930. 00 and 2469.50, 1864.50, 1734.00. There were no significant difference of Cho, Cr, and NAA between the two groups (P > 0. 05). In the 14 cases whose normal brain tissue were compared with the recurrent tumor tissue in tumor recurrence group, the median of Cr, NAA, LL, Cho/Cr, Cho/NAA, LL/Cr of recurrent tumor tissue and normal brain tissue were 1023.00, 1930.00, 2090.00, 3.76, 2. 13, 3.39 and 2370.00, 3012.00, 1680.00, 1.64, 1.17, 0.75,The difference of Cr, NAA, LL, Cho/Cr, Cho/NAA, LL/Cr between the normal tissue and recurrent tumor tissue were significant (P <0.05). LL, Cho/Cr, Cho/NAA, LL/Cr of recurrent tumors were higher than those of the normal brain tissue,while NAA and Cr of recurrent tumors were lower than those of the normal brain tissue. In the 12 cases whose normal brain tissue were compared with the RE tissue in RE group, the median of Cho, Cr, NAA, LL, Cho/Cr, IX,/Cr of RE tissue and normal brain tissue were 390.00, 217.50, 427.50, 39.00, 1.30, 0.40 and 680.00, 360.00, 610.00, 30.00, 1.54, 0. 09. The difference of above-mentioned parameters between RE tissue and normal tissue were significant. Cho, Cr, NAA, Cho/Cr of RE were lower than those of normal tissue (P <0. 05) ,while LL and LL/Cr of RE were higher than those of normal tissue (P < 0. 05). Conclusion The changes of the metabolites in recurrent lesions and RE lesions were different on MRS. Parameters such as Cho/Cr, Cho/NAA and LL/Cr, which were higher in recurrent lesions than those of RE, were valuable for the differential diagnosis between basicranial tumor recurrence and radiation encephalopathy after radiotherapy for NPC.
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Objective To find the effective quantitative parameters for the differentiation of the breast lesions using the post-processing of time.signal curve of 3D dynamic-enhanced MRI.Methods Thirty patients with 35 lesions underwent 3D dynamic-enhanced MRI and the time-signal cHIve was deduced.The four quantitative parameters including SImax,PH,Slope and SlopeR were analyzed in benign andmalignant lesions of the breast.Independent samples t test and rank sum test were used for the statistics.Results Seyenteen benign lesions and 18 malignant lesions were included in this study.The SImax(M)of benign and malignant lesions were 375.2 and 158.1,the 95% confidence intervals of SImax were 278.2-506.0 and 160.5-374.8.The PH(M)of benign and malignant lesions were 114.4 and 87.8,the 95% confidence intervals of PH were 73.7-196.5 and 71.3-162.9.The Slope(M) of benign and malignant lesions were 22.3×10-3 and 44.0×10-3,the 95% confidence intervals of Slope were 13.7×10-3-41.1×10-3 and 46.1×10-3-81.8×10-3.The Slope"(M) of benign and malignant lesions were 2.6 and11.4,the 95% confidence intervals of SlopeR were 1.9-3.4 and 9.8-14.5.There were no significant differences on SImax and PH between benign and malignant lesions(P>0.05).The significant differences existed on Slope(P<0.01)and SlopeR(P<0.01)between benign and malignant lesions of the breast.Conclusion SlopeR is a very effective parameter in t}le differential diagnosis of breast lesions.