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Objective To compare with the advantage or shortage of several scan series in imaging of normal articular cartilage in knee.The MR manifestation were observed and thickness of different location of cartilage in knee in different series were calulated.Methods The knees of 30 healthy volunteers were imaged with five different MR imaging sequences including T 1-weighted,proton density-weighted,T 2-weighted FSE,STIR and 3D-FS-SPGR.The value of CNR were determined for cartilage versus a saline fluid phantom,marrow fat,and muscle.The MR 2D and 3D manifestation were observed and thickness of different location of cartilage in knee in different series were calculated.Results The value of CNR of 3D-FS-SPGR for cartilage versus a saline fluid phantom,marrow fat,and muscle were compared with other sequences and were significantly different.The values of cartilage thickness with 3D-FS-SPGR were more than those with other series.The mulplaner appearance was observed.There was five-plane manifestation when cartilage thickness was more than 4 mm.The value of cartilage thickness of male and female were 2.63 mm and 2.52 mm,respectively.Conclusion 3D-FS-SPGR sequences have significant advantage compared with other series in imaging normal articular cartilage of knee.The cartilage is show clearly than other sequences.The value of cartilage thickness with 3D-FS-SPGR is more accurate.Moreover it can also provide much information adding to 3D construction of cartilage.
RESUMO
Objective To recognize CT signs of parapharyngeal space (PPS) changing in nasopharyngeal carcinoma (NPC) further.Methods 30 patients with proven NPC by biopsy were performed CT and MR scanning before radiotherapy. Results According to CT findings,four types of PPS display in 30 cases were found,each of which was observed and compared with MR findings and were as follows: (1)PPS ,which had no changing on CT, showed fat-filled triangular space continuously on MRI. (2) PPS, which became narrow and linear hypodense on CT,showed that fat intensity was pressed, but continuously on MRI; (3) PPS, which became narrow and linear hyperdense on CT,showed fat intensity,was pressed exceedingly but continuously either on MRI. (4)PPS,which was diminished on CT, showed the mass occupied PPS and lateral pterygoid muscles was pushed, medial fatty space of which was diminished, but intensity of medial or lateral pterygoid muscles was normal or abnormal on MRI. Conclusion (1)When PPS becomes narrow on CT,whether PPS shows hyperdense or hypodense,the mass makes a breakthrough PPS. (2) When PPS is diminished completely on CT,the mass steps PPS to the infratemporal fossa.