ABSTRACT
Objective To investigate the enhanced CT features of papillary renal cell carcinoma (PRCC)and its subtypes (PRCC-Ⅰ, PRCC-Ⅱ)and chromophobe renal cell carcinoma(CRCC).Methods The CT features of 30 tumors with pathologically proved PRCC and CRCC were analyzed retrospectively,including location,size,enhanced types,calcification and necrosis etc.The differences in the CT features among PRCC and its subtypes and CRCC were evaluated.Results 1 2 cases of PRCC with single lesion (7 in the right kidney and 5 in the left)were shown;1 case was multifocal PRCC with 1 lesion in the right kidney and 2 lesions in the left.1 5 cases of CRCC were single lesion(9 in the right kidney and 6 in the left).The medium tumor maximum size of CRCC was larger than that of PRCC,and the PRCC-Ⅰ tumors tended to be smaller than PRCC-Ⅱ ones.53% of the PRCC had heterogeneous enhancement,and all calcification and necrosis were found in PRCC-Ⅱ lesions.Of all the CRCC,27% had uniform enhancement,20% had calcification and 40% had necrosis or central scar.There was no significant difference between PRCC and its subtypes and CRCC in location, maximum size,heterogeneity,calcification,necrosis and central scar.The degree of enhancement of CRCC(89.53 HU)was significantly greater than that of PRCC(66.60 HU),PRCC-Ⅰ(71.75 HU)and PRCC-Ⅱ(64.73 HU)in the cortical phase(P<0.05).The enhancement peak in the nephrographic phase was CRCC,PRCC-Ⅰ,PRCC and PRCC-Ⅱ from high to low in turn,which were all higher than that in cortical phase.In the excretory phase,the enhancement of all lesions was declined.Conclusion Contrast-enhanced CT is of certain value in the differential diagnosis among PRCC and its subtypes and CRCC.The enhancement degree of CRCC in the cortical phase is significantly greater than that of PRCC and its subtypes.The enhancement peak of PRCC and its subtypes and CRCC appears in the nephrographic phase.
ABSTRACT
Objective To compare the image quality of diffusion-weighted MR neurography (DW-MRN) of the tibial nerve and the common peroneal nerve prospectively using different motion probing gradients (MPGs).Methods A total of 21 healthy volunteers underwent DW-MRN at the knee (unilateral imaging) on a 3.0 T magnetic resonance system with unidirectional MPGs.The protocol included anteriorposterior unidirectional,right-left unidirectional,three-directional and six-directional MPGs.The apparent SNR and CNR of tibial nerve and common peroneal nerve were calculated.Three-dimensional MIP images of the nerves were evaluated blindly by two radiologists using a four-point grading scale on basis of entirety depiction and the signal intensity.Significance was determined by using Friedman and paired Wilcoxon tests.Results The SNR of tibial nerves on DW-MRN with anterior-posterior,right-left,three directional and six directional MPGs were 4.17 (2.70-5.65),4.35 (0.47-4.69),3.46 (2.27-4.62) and 3.30 (2.06-4.43),respectively.CNR were 0.61 (0.46-0.70),0.63 (0.36-0.73),0.55 (0.39-0.64) and 0.53(0.35-0.63),respectively.The scores of tibial nerve image quality were 4.0 (2.0-4.0),4.0 (3.0-4.0),2.5 (2.0-3.5),2.0 (1.0-2.5),respectively.Interobserver agreement was good and the Kappa value was 0.69 (P ＜ 0.05).The SNR of the common peroneal nerves on DW-MRN with anteriorposterior,right-left,three directional and six directional MPGs were 3.05 (2.30-4.20),3.05 (2.26-4.34),2.72 (1.84-13.80) and 2.68 (1.87-3.67),respectively.CNR were 0.51 (0.39-0.62),0.51 (0.39-0.63),0.46(0.30-0.86) and 0.46(0.30-0.57),respectively.The scores of the common peroneal nerve image quality were 3.5 (2.0-4.0),4.0 (2.0-4.0),2.0 (1.0-3.0) and 2.0 (1.0-2.5),respectively.Interobserver agreement was good and the Kappa value was 0.70(P ＜0.05).For SNR,CNR and nerve image quality of the tibial nerves and the common peroneal nerves,there were significant differences among different MPGs (x2 =215.01,215.01,60.49 and 182.82,182.82,60.22,respectively,P ＜ 0.05).SNR,CNR and nerve image quality of the tibial nerves and the common peroneal nerves on DW-MRN with unidirectional MPGs were better than those with three-directional and sixdirectional MPGs (Z =-6.90-4.03,P ＜ 0.05).The SNR and CNR of the tibial nerves on DW-MRN with right-left direction were better than those with anterior-posterior unidirectional MPGs (Z =-3.53,-3.41,P ＜ 0.05),but there was no significant difference of image quality between right-left and anteriorposterior directional MPGs (Z =-0.58,P ＞ 0.05).DW-MRN of the tibial nerves with three-directional MPGs was better than that with six-directional MPGs (Z =-3.00,-2.80,-3.92,P ＜ 0.05).There were no significant differences between right-left and anterior-posterior unidirectional MPGs,or between three-directional and six-directional MPGs of common peroneal nerves (Z =-1.94--0.31,P ＞ 0.05).Conclusions DW-MRN has capability to provide three-dimensional visualization of the tibial and common peroneal nerves,and the image quality with unidirectional MPGs is better than that with three or six directional MPGs.