The assessment of lymphatic system in lymphedema with magnetic resonance lymphangiography / 实用放射学杂志

Objective To evaluate the MR lymphangiography (MRL)in diagnosis of limb lymphedema.Methods A total of 582 patients with lymphedemtous limbs were enrolled in the study,MRL was performed at 3.0T MR.The morphology and enhancement of the lymph nodes,the number of lymphatic vessels and the lymph flow were evaluated.Results No matter in primary or secondary lymphedema,there were patients showed only lymph nodes affected,or only lymph vessels affected,and some patients showed both affected.Lymphatic aplasia,hypoplasia or hyperplasia were showed in primary lymphedema.Obstruction lymphatic vessels,and lym-phangiectasia were showed in secondary lymphedema.The velocity of lymph flow was (1.0±0.62)cm/min in affected limb of pa-tients with primary lymphedema,which was significantly slower than that of affected limb of patients with secondary lymphedema (2.22±1.64)cm/min(P<0.01)in dynamic contrast-enhanced MRL.In both type of lymphedema,the contrast enhanced lymph nodes showed less nodes with delayed enhancement and lower signal intensity,compared to that of lymph nodes in the contralateral normal side.Conclusion Dynamic contrast-enhanced MRL is helpful for assessing the anatomical and functional status of lymphatic system in lymphedematous limb.This new imaging techniques provides a powerful tool for the diagnosis of lymphedema.

Cross-sectional areas of calf soft tissue measured with MRI as a new method for staging gynecologic oncology-related extremity lymphedema / 实用放射学杂志

Objective To determine whether the cross-sectional area (CSA)of the calf measured with MRI could stage lower ex-tremity lymphedema (LEL)secondary to gynecological cancer treatments.Methods 148 patients were enrolled in this research.116 females with unilateral LEL and 32 without LEL after gynecological cancer treatments underwent calf MRI and water displacement. Total soft tissue CSA (T),muscle CSA (M)and subcutaneous tissue CSA (S)of affected calf,and difference of T (DT),M (DM) and S (DS)between calves were obtained on MRI at mid-calf level.Volume of affected calf and difference of volume (DV)between calves were obtained by water displacement.Statistical analysis was performed to determine feasibility of MRI measurements for ac-cessing LEL.Results There were close correlations between volume and T or S of affected calf,and between DV and DT or DS of calves.The correlations of stages of LEL with T and S of affected calf as well as DT and DS were stronger than the volume of affect-ed calf and DV (P< 0.01).Multivariate analysis showed more significant differences in T and S than in volume of affected calf,and in DS than in DV between LEL stages (P< 0.05).No difference was found in volume of affected calf and in DV between stage 0 andⅠ. For staging LEL,DS showed the most profound discrimination ability among all measurable parameters.Conclusion DS of calves could be the most reliable parameter recommended for staging and early diagnosis of LEL.

Differentiating peripheral lung cancers from inflammatory masses using dual energy spectral CT imaging / 中华放射学杂志

Objectives To investigate the clinical significance of dual energy spectral CT (DESCT) in quantitatively differentiating peripheral lung cancers from pulmonary inflammatory masses.Methods Sixty patients with 35 lung cancers and 25 inflammatory masses underwent DESCT to get arterial phase (AP) images and venous phase (VP) images.Iodine concentrations in the central and peripheral zone of the masses were measured and normalized to the aorta as normalised iodine concentration (NIC).The difference of NIC between central and peripheral zone of the masses (dNIC) was calculated.The spectral attenuation curve was obtained automatically and the slope of curve (λHU) was also calculated in the two groups.The quantitative parameters was presented as M (Q1,Q3),and Wilcoxon signed rank test was used to compare above two independent samples.Receiver operating characteristic (ROC) curves were generated to calculate the sensitivity and specificity.Results NICs in the central zone of peripheral lung cancers were significantly lower than that of inflammatory masses:mean NICs were 0.03 (0,0.05) versus 0.12 (0.07,0.20) in AP,and 0.14 (0.12,0.19) versus 0.30 (0.21,0.57) in VP (Z=-4.14,-3.70,respectively,P＜0.01).While the dNIC values of lung cancers were significantly higher than that of inflammatory masses:dNIC values were 0.08 (0.05,0.11) versus 0.04 (-0.02,0.08) in AP,and 0.23 (0.17,0.34)versus 0.07 (-0.04,0.08) in VP(Z=-2.56,-4.00,respectively,P＜0.05).Mean λHU values of lung cancers were also lower than inflammatory masses:1.03 (0.67,1.67)versus 2.75 (1.61,3.19) in AP,and 1.58 (1.30,2.17) versus 3.25 (2.37,4.54) in VP (Z=-3.90,-4.42 respectively,P＜0.01).According to ROC curves,cutoff value of λHU =2.11 in VP had the highest sensitivity (89％) and specificity (91％) in differentiating peripheral lung cancers from inflammatory masses.Conclusions Contrast-enhanced dual energy spectral CT imaging with some quantitative parameters such as normalised iodine concentration,dNIC,and the slope of spectral attenuation curves may be a promising new method for differentiating peripheral lung cancers from inflammatory masses.

Spectral CT imaging in the diagnosis of pulmonary embolism using quantitative iodine-based material decomposition images / 中华放射学杂志

Objective To assess the diagnostic value of CT spectral imaging using quantitative iodine-based material decomposition images in the evaluation of pulmonary embolism. Methods Fifty-three patients underwent CT angiography with spectral imaging mode on a GE Discovery CT750HD scanner. Iodine distribution in the lung parenchyma using the iodine-based material decomposition images was quantitatively measured by post-processing. Monochromatic CT angiographic images were reconstructed from the same data sets and thee images were reviewed for the identification and localization of pulmonary embolism as well as the degree ( partial or complete) of the embolic occlusion. The number and location of perfusion defects were recorded. The iodine content of perfusion defects and normal lung parenchyma on the iodine maps were measured by one reader using an ROI analysis. Comparative analyses were obtained using the Chi-square test for categorical data. Two independent samples rank test and 2 related samples signed-rank test were used to compare iodine densities between different groups. Results CT angiography showed no pulmonary embolism in 33 patients, and iodine distribution was homogeneous. A total of 93 clots with lobar ( n = 26), segmental (n = 54) and sub-segmental (n=13) distribution were detected in 19 patients; Fifty-one clots were occlusive and 42 clots were non-occlusive. The iodine-based material decomposition images of all occlusive clots showed lobar, segmental or sub-segmental iodine distribution defects; whereas eleven of 42 non-occlusive clots had evidence of iodine distribution defects. There was significant difference ( x2 = 39. 94,P＜0. 01 ) in the perfusion defects between occlusive and non-occlusive clots. There was a significant difference in iodine content between normal lung parenchyma [ (1.92 ±0. 54) g/L] and perfusion defects [ (0. 30 ± 0. 20)g/L] (Z= -5.63, P ＜ 0. 01 ). There was a significant difference in the iodine content of peffusion defects before [ (0. 26 ± 0. 23 )g/L] and after anticoagulation [ (0. 94 ± 0. 50 )g/L ] ( Z = -3.93,P ＜ 0. 01 ). Conclusion With the ability of iodine mapping, CT spectral imaging is areliable method in the evaluation of pulmonary embolism both qualitatively and quantitatively, and may be a useful tool in providing information regarding the severity of PE and monitoring therapeutic efficacy.