| Part I Different MR platform on liver Magnetic resonance Diffusion weighted imagingPurpose:To investigate the effect of two different MR platform on the ADC measurement and its reproducibility in liver DWI.Methods: Two groups of volunteers (33cases in each group) underwent liver DWI examination twice at using the same DWI sequence with b value of0and800s/mm2on a1.5Tesla Siemens and Philips MR scanner, respectively. On ADC maps,2Region-of-interests (ROIs) were placed on three central slices of the right and left liver lobe, respectively. The ADC measurements of6ROIs on the left and right liver lobe were averaged to represent the mean ADC values of the left and right liver lobe, respectively. The reproducibility of the ADC measurements was assessed by use of Bland-Altman method.Results: The ADC values measured on Siemens (the first, left:1.479±0.163×10-3mm2/s, right:1.282±0.071×10-3mm2/s; the second, left: 1.527±0.164×10-3mm2/s, right:1.295±0.084×10-3mm2/s) The ADC values measured on Philips (the first, left:1.443±0.154×10-3mm2/s, right:1.217±0.104×10-3mm2/s; the second, left:1.439±0.185×10-3mm2/s, right:1.226±0.115×10-3mm2/s)The ADC values measured on Siemens was significantly higher than those of Philips on the left and right liver lobe (t=2.045-2.713,P<0.05) and the ADC values of the left liver lobe were higher than those of the right liver lobe with both scanners (the first, left Siemens:1.479±0.163×10-3mm2/s, Philips:1.443±0.154×10-3mm2/s; the second, Siemens:1.527±0.164×10-3mm2/s, Philips:1.439±0.185×10-3mm2/s)(the first, right Siemens:1.282±0.071×10-3mm2/s, Philips:1.217±0.104×10-3mm2/s; the second, Siemens:1.295±0.084×10-3mm2/s, Philips:1.226±0.115×10-3mm2/s)(t=-10.561-7.263, P＜0.001). The reproducibility ADC measurement was comparable on both MR scanners, and all displayed higher reproducibility on the right liver lobe as compared to the left liver lobe,and the Bland-Altman analysis showed the agreement of7.55%and16.65%for the right and left liver lobe respectively with Siemens scanner, and7.85%and16.3%with the Philips scanner.Conclusions:The liver ADC values, but not its reproducibility were affected by the MR scanner; caution should be taken when to compare the ADC values measured on different MR scanners.Part Ⅱ Feasibility of magnetic resonance diffusion-weighted IVIM and its reproducibility in normal liver DWIPurpose: To investigate the feasibility of magnetic resonance diffusion-weighted IVIM and its reproducibility in normal liver DWI.Methods:Thirty-five young healthy volunteers underwent liver DWI examination twice with the same sequence and b values (b=0,10,20,30,40,50, 75,100,150,300,500,800s/mm2) on a1.5Tesla Philips MR scanner. D, D*and f maps were generated by a manufacturer-supplied software(PRIDE DWI Tool, version1.5, Philips Healthcare). Six Region-of-interests (ROIs)(3ROIs in left and right liver lobe, respectively) were drawn on three consecutive middle slices. The average values of D, D*and f were measured and compared between the left and right liver lobe. The reproducibility of D, D*and f were evaluated with Bland-Altman method.Results:The values of D, D*and f of left liver lobe [D(×10-3mm2/s):1.250±0.210, D*(×10-3mm2/s);101.906±15.063, f(%):22.954±5.268] were statistically higher than those of right liver lobe[D(×10-3mm2/s):1.039±0.124, D*(×10-3mm2/s):100.127±20.757, f(%):18.317±3.671](D, F:t=-9.685～5.838, P＜0.001; D*:t=-1.210-0.523, P=0.232-0.605), however their reproducibility of left liver lobe (limit of agreement[LOA]:22.55%,51.05%,39.3%, respectively) were lower than those of right liver lobe (LOA:20.3%,39.25%,33.9%). The D values had a best reproducibility in both the left and right liver lobe.Conclusions:The liver DWI-IVIM is feasible in liver, and the value of D,and f of left liver lobe were higher that those of right liver lobe but with worse reproducibility. The D value was most reproducible.Part Ⅲ Feasibility of magnetic resonance diffusion-kurtosiss imaging and its reproducibility in normal liverPurpose: To investigate the feasibility of magnetic resonance diffusion-kurtosiss imaging and its reproducibility in normal liver. Methods:Thirty-five young healthy volunteers underwent liver DKI examination twice with the same sequence and b values (b=0,10,20,30,40,50,75,100,150,300,500,,800s/mm2) on a1.5Tesla Philips MR scanner. D and K maps were generated by a manufacturer-supplied software(PRIDE DWI Tool, version1.5, Philips Healthcare). Six Region-of-interests (ROIs)(3ROIs in left and right liver lobe, respectively) were drawn on three consecutive middle slices. The average values of D and K were measured and compared between the left and right liver lobe. The reproducibility of D and K were evaluated with Bland-Altman method.Results:The values of D and K of left liver lobe (D:1.958×10-3mm2/s, K:1.548) were statistically higher than those of right liver lobe(D:1.722×10-3mm2/s, K:1.285)(D、K:t=-5.665-8.095, P<0.001), however their reproducibility of left liver lobe (limit of agreement[LOA]:30.2%and29.65%, respectively) were lower than those of right liver lobe (LOA:18.9%and17.4%).Conclusions:The liver DKI is feasible in liver, and the value of D and K values of left liver lobe were higher that those of right liver lobe but with worse reproducibility. |
PDF Full Text Request