The Influence On~1H-MRS Of Liver Lesion With The Method Of Probe And Spectrum Post-processing

Objective: To compare the difference among the1H-MRS images of metabolitesdetected of liver lesion both using Probe and using Spectrum methods.Material and methods:Review52the cases of1H-MRS of liver lesion includingthe hemangioma of the liver (16),23cases of hepatocellularcarcinoma and livermetastases (13), which are the typical imagesof liver lesion confirmed clinically andpathologically.We use GE1.5T superconducting NMRspectrometer with shaft positionof T2WI as its locating image, and in ROI the voxel is2cm×2cm×2cm.TO avoid capsulechanging，the bleeding and necrotic area, increase the pre-saturated zone all aroundROI,adopt breathing trigger technology and select three minutes and15seconds as thespectrum acquisition time. Theoriginal images are processed respectively with Probeand Spectrum methods for the post-processing. The software can automaticallycalculate the peak heights and the area under the peaks after selecting the metaboliteswave manually(about0.05error). Using Probe method we can observe the wave peaksof fat methylene1.3ppm, of choline complex3.2ppm and of other(including the peak offat methyl0.9ppm,of the adjacent hydroxyl and olefinic group2.0ppm and2.8ppm, ofglucose/glycogen3.6-3.9ppm).Also can we observe the display rates and thedifferencesof every peak height and the area under the peak. Using Spectrum method we can watchthe peaks of water4.7ppm, of fat methylene1.3ppm, of choline complex3.2ppm andget the display rates and the differences of every peak heights and the area under thepeaks. Every group of peak heights and the area under the peaks with thetwo methodsdon’t meet normal distribution.So we adopt the method of the rank sum test withP<0.05to get the comparisons of all three groups and each two groups in heights andthe area under the peaks.Results: the appear rate of the peak of1.3ppm and3.2ppm is100%by the Probe post-processing,while the other wave peaks (0.9ppm,2.0ppm,2.8ppm,3.6-3.9ppm)donot constantly appear. The other appear rates of peak heights of hepatocellularcarcinoma group respectively are69.57%、82.61%、26.09%、60.87%. The other appearrates of peak heights of liver metastases group respectively are84.62%、84.62%、61.54%、61.54%.The other appear rates of peak heights of hemangioma grouprespectively are37.50%、56.25%、0%、62.50%; The differences of peak heights in threegroups of3.2ppm peak have statistic significance (P<0.05), while the differences ofpeak heights between liver hemangioma group and hepatocellular carcinoma group，liver hemangioma group and liver metastases group have statistical significance(P <0.05). The differences of peak heights compared between the hepatocellular carcinomagroup and liver metastases group have no statistical significance (P>0.05). Thedifferences of the peak heights in trhree groups of lesions choline complex and betweentwo groups have no statistical significance in1.3ppm、0.9ppm、2.0ppm、3.6-3.9ppmpeak (P>0.05).2.8ppm peak have no appear in liver hemangioma group，Thedifferences of the peaks compared between hepatocellular carcinoma group and livermetastases group have no statistical significance (P>0.05).The differences of the areasunder the peaks in three groups of3.2ppm peak have statistic significance (P <0.05),and the differences of the areas under the peaks between liver hemangioma group andhepatocellular carcinoma group have statistic significance(P <0.05).The differences ofthe areas under the peaks compared between liver hemangioma group and livermetastases group, the hepatocellular carcinoma group and liver metastases group haveno statistical significance(P>0.05); The differences of the peak areas under the peaksin three groups of lesions choline complex and between two groups have nostatisticalsignificance in1.3ppm、0.9ppm、2.0ppm、3.6-3.9ppm peak (P>0.05)；2.8ppm peakhave no appear in liver hemangioma group，The differences of the areas under the peakscompared between hepatocellular carcinoma group and liver metastases group have nostatistical significance (P>0.05). The method of Spectrum post-processing mainlydisplay4.7PPM and1.3PPM peak, and the appearance both of them are100%.3.2ppm peak is not constant appear, of hepatocellular carcinoma group is78.26%（18/23）,of liver metastases group is69.23%（9/13）, of hemangioma group is37.50%（6/16）;The differences of peak heights in three groups of3.2ppm peak have statisticalsignificance (P<0.05), while the differences of peak heights between liver hemangiomagroup and hepatocellular carcinoma group have statistical significance(P <0.05). Thedifferences of peak heights compared between liver hemangioma group and liver metastases group, the hepatocellular carcinoma group and liver metastases group haveno statistical significance (P>0.05); The differences of peak heights of4.7ppm and1.3ppm in three groups of lesionscholine complex or between every two groups have nostatistic significance (P>0.05). The differences of the area under the peaks in threegroups of peak3.2ppm have statistic significance (P <0.05), and the differences of theareas under the peaks between liver hemangioma group and hepatocellular carcinomagroup have statistical significance(P <0.05). The differences of the areas under thepeaks compared between liver hemangioma group and liver metastases group, thehepatocellular carcinoma group and liver metastases group have no statisticalsignificance (P>0.05); The differences of the areas under the peaks4.7ppm comparedbetween liver hemangioma group and liver metastases group have statisticalsignificance (P <0.05)；The differences of the areas under the peaks1.3ppm in threegroups of lesions choline complex or between every two groups have no statisticsignificance (P>0.05).Conclusion: The method of Probe post-processing can show more peaks, which isadvantageous to observe when having less metabolite peaks. In this method the1.3ppmand3.2ppm peaks appear constantly,however do not the0.9ppm,2.0ppm,2.8ppm and3.6-3.9ppm peaks.Except the3.6-3.9ppm peaks, other metabolite peaks are shownmoreobviously in liver metastatic tumor group and hepatocellular carcinomagroup thanin liver hemangioma group.Then it can provide referent information in theidentification of malignant tumor or benign tumor. the2.8ppmpeaks do not appear inliver hemangioma group, and3.6-3.9ppm peaks have not obvious difference in all threegroups, so it is not valuable to identify them. And The method of Probe post-Spectrumonly can detect a little metabolite, which mainly are constantlyappearing4.7ppm and1.3ppm peaks and occasionally appearing of3.2ppm peaks. The appearing rate of3.2ppm peaks in liver metastatic tumor group and hepatocellular carcinoma group is higherthan in liver hemangioma group, which is mainly because the metabolism of cholinecomplex of malignant tumor is exuberant. Using the two methods, the statistical resultsof3.2ppm peaks are consistent in hepatocellular carcinoma group and liverhemangioma group. With the analysis of ROC diagram, it can provide better sensitivityusing spectrum post-processing than using probe post-processing in diagnosis of thehepatocellular carcinoma...