| Partâ… To Study the Technical Parameters of Hepatic 10-phase Dynamic Enhancement with Liver Acceleration Volume Acquisition(LAVA) at 3.0T MRIPurpose:To analyze the signal intensity time curves and the phase of hepatic vascular reconstruction at normal liver and hepatic cirrhosis by whole liver perfusion weighted imaging,in order to investigate the technical parameters of hepatic 10-phase dynamic enhancement with liver acceleration volume acquisition(LAVA) at 3.0 T MRI.Materials and Methods:Perfusion weighted images of whole liver were performed in 8 health adults and 8 patients with hepatic cirrhosis,in order to investigate the technical parameters of hepatic 10-phases dynamic enhancement with liver acceleration volume acquisition(LAVA) at high field 3.0 T MRI.(1) After bolus injection 20 ml GD-DTPA(the injection rate was 3ml/s) of 10 seconds in anterior ulnar vein by high-pressure syringe,perfusion weighted images of whole liver were performed with LAVA technique at quiet breath by a 3.0 T MRI(GE medical system). With section thickness of 4.4 mm,scan time of 7s,40 slices of whole liver were scan every phase.The total 864 slices(72 slices were reconstructed every phase) were reconstructed with 12 phases scan continuously at 84 seconds.(2) The scanned images were processing by adw4.2 workstation.The signal intensity-time curves of abdominal aorta,portal vein,hepatic vein and liver parenchyma were drawn and the peak time,fluctuant time and the simultaneously reach time of balanced phase were analyzed in both normal liver and hepatic cirrhosis. Results:(1) The signal intensity time curve of abdominal aorta was rapid ascending and rapid descending both at health adults and patients with hepatic cirrhosis.The peak time of the abdominal aorta enhancement was 25.75s,26.63s;Time segments of fluctuant state were 17～31s,17～38s respectively.The signal intensity time curve of portal vein was rapid ascending and slow descending.The peak time of portal vein enhancement were 45s,53.75s,Time segments of the fluctuant state were 31～59s and 38～66s respectively.The peak time of portal vein was longer than abdominal aorta and the intensity of enhancement was weaker than abdominal aorta obviously.The signal intensity time curve of hepatic vein was slow ascending and slow descending. The peak time of hepatic vein enhancement was 59.88s,68.63;Time segments of the fluctuant state were 45～73s and 52～80s respectively.The signal intensity time curve of liver parenchyma was slow ascending and slow descending.The signal intensity of liver parenchyma increases slowly in arterial phase and rapidly reached the peak in portal phase.And then,it decreases slowly and keeps relative stationary state.The peak time of hepatic parenchyma enhancement was 52.88s,59.88s;Time segments of the fluctuant phase were 38～66s and 45～73s respectively.The simultaneously reached equilibrium phase time of abdominal aorta,portal vein,hepatic vein and liver parenchyma was 68.25s,77.38s;the time segments of equilibrium phase were 66～94s, 73～94s respectively.(2) The peak time of abdominal aorta has no significant difference between health adult and patients with hepatic cirrhosis(P＞0.05).But the peak time of portal vein,hepatic vein and liver parenchyma and the real time of equilibrium phase have significant difference(P＜0.05).It illustrates the blood supply of portal vein in patients with hepatic cirrhosis longer than the healthy.(3)There was significant difference between the peak time phase and other phase of showing the quality of hepatic artery,portal vein and hepatic vein imaging(P＜0.05).Conclusion:(1) The scan mode can reflect the hemodynamic alteration procedure at both normal liver and liver cirrhosis;it is an ideal and practical pre-scan procedure, which included hepatic artery,portal vein,hepatic vein,liver parenchyma and equilibrium phase entirely.The optimal phases to observe and reconstruct vessel of hepatic artery,portal vein and hepatic vein are the peak time phase images correspondingly.(2) The optimal scan mode include with breath holding method,the time of arterial 3 phases at 10～31s,12～33s,vein 3 phases at 40～61s,45～66s, equilibrium 3 phases at 70～91s,75～96s for normal adults and patients with hepatic cirrhosis respectively,which could include all the fluctuant phases and equilibrium phases of whole liver entirely. Partâ…¡The Detection and Diagnosis of Hepatic Nodular Lesions with 3.0T MRI Ten-phase Dynamic ScanningObjective:To assess the value of MRI ten-phase dynamic scanning in the detection and diagnosis of hepatic nodular lesions,to analyze the sensitivity,specificity, accuracy,false negative rate and false positive rate of multi-phase combination scans, and to summarize the enhancement features of nodular lesions in different phase and their optimal enhancing scan projects.Materials and Methods:Ten-phase dynamic enhanced images of whole liver were performed with LAVA volume technique in 180 cases with hepatic nodular lesions (hepatic cirrhosis after hepatitis with or without hepatic cancer,Hepatic Metastases and other rare nodular lesions).All images were processed with adw4.2 workstation and GC RIS PACS,time-intensity curves for abdominal aorta,portal veins and hepatic parenchyma were obtained.Ten-phase images including arterial three phases, portal vein three phases,hepatic venous three phases and balanced 3 phases were analyzed.The values of different phase to demonstrate lesions were assessed,as well as multi-phase combination.The dynamic enhancement features of hepatic nodular lesions and their optimal scan projects were summarized.Results:148 cases(82.2%) completed scans of ten phases including arterial three phases,portal vein three phases,hepatic venous three phases,balanced three phases and delayed phase.1 Enhancing features in different phase(1) 80 lesions in 54 cases of hepatic cirrhosis after hepatitis with liver cancer:â‘ Enhancement persists for 2 or 3 phases in 65%and 28.75%respectively.â‘¡Enhancement mainly begins at arterial phase,arterial early phases in 25%,arterial middle phase in 62.5%and arterial late phase in 12.5%.â‘¢Optimal phases to observe enhancement(enhancing phase) were arterial middle phase in 87.5%and arterial late phase in 93.75%.â‘£Fastest signal attenuation of tumors was observed at portal middle phase in 72.5%(fastest attenuation phase).⑤The optimal phases to observe signal attenuation(attenuation phase) were portal middle,late phase,hepatic venous late phase and balanced phase in 75%,86.25%,96.25%and 100%respectively.(2) 33 lesions in 20 cases with liver cancer after intervention treatment:â‘ Enhancement persists for 2 or 3 phases in cases of 75.76%and 24.24%respectively.â‘¡Enhancement mainly begins at arterial phase,arterial early phase in 15.15%, arterial middle phase in 63.63%and arterial late phase in 21.21%.â‘¢The optimal phases to observe enhancement were arterial middle phase in 78.79%,and arterial late phase in 90.91%.â‘£Fastest signal attenuation of tumors(fastest attenuation phase) were observed at portal middle phase in 45.45%and portal late phase in 36.36%.⑤The optimal phases to observe signal attenuation(attenuation phase) were portal middle,late phase and hepatic venous middle phase in 54.55%,90.90%and 100% respectively.(3) 29 lesions in 56 cases with hepatic cirrhosis after hepatitis accompanying liver cancer or not,including 12 cases with regenerative nodules or dysplastic nodular(RN or DN):â‘ Enhancement persists for 2 or 3 phases in 58.62%and 34.48%respectively.â‘¡Enhancement begins at arterial phase for most lesions,arterial early phases in 31.03%and arterial middle phase in 62.07%.â‘¢The optimal phases to observe enhancement were arterial early,middle and late phase in 31.03%,82.76%and 34.48%respectively.â‘£Fastest signal attenuation of tumors were observed at arterial late phase in 55.17%and portal middle phase in 34.48%.⑤The optimal phases to observe signal attenuation(attenuation phase) were arterial late phase in 65.52%and portal middle phase in 100%.(4) Hyper-vascular Hepatic Metastases(70 lesions in 24 cases with primary breast carcinoma):â‘ Enhancement persists for 2 or 3 phases in cases of 57.14%and 32.86%respectively.â‘¡Enhancement begins at arterial phase for most lesions,arterial early,middle and late phase in 14.29%,51.43%and 34.29%,respectively.â‘¢The optimal phases to observe enhancement(enhancing phase) were arterial middle,late phase,portal middle and late phase in 65.71%,97.14%,47.14%and 30%respectively.â‘£Fastest signal attenuation of tumors were observed at portal middle,late phase and hepatic venous phase in 44.29%,25.71%and 24.29%respectively.⑤Optimal phases to observe signal attenuation(attenuation phase) were portal middle,late phase, hepatic venous middle phase and balanced phase in 44.29%,70%,94.29%and 94.29%respectively.(5) Hypo-vascular Hepatic Metastases(126 lesions in 43 cases with primary digestive tract or lung tumors):â‘ Enhancement persists for 2 or 3 phases in cases of 65.08% and 30.95%respectively.â‘¡Enhancement begins at arterial phase for most lesions, arterial middle and late phase in 20.63%and 65.87%,respectively.â‘¢The optimal phases to observe enhancement(enhancing phase) were arterial middle,late phase, portal middle and late phase in 20.63%,85.61%,87.30%and 34.92%,respectively.â‘£Fastest signal attenuation of tumors were observed at portal late phase in 65.08% and hepatic venous middle phase in 26.19%.⑤The optimal phases to observe signal attenuation(attenuation phase) were portal late phase,hepatic venous middle phase and balanced phase in 65.08%,91.27%and 99.21%respectively.(6) 8 lesions in 5 cases with focal nodular hyperplasia:â‘ Enhancement persists for 2 or 3 phases in cases of 25%and 62.5%respectively.â‘¡Enhancement mainly begins at arterial early and middle phases in 37.5%and 62.5%respectively.â‘¢The optimal phases to observe enhancement were early arterial and peak phase in 37.5%,100% respectively.â‘£Fastest signal attenuation of tumors was observed at portal peak phase for 50%and late portal phase for 50%.⑤Central scars enhancement begins at late portal phase and balanced liver parenchyma phase in 25%and 62.5%respectively.2 The diagnosis value of LAVA ten phases and multi-phase combination(1)The sensitivity,specificity,accuracy,false negative rate and false positive rate in diagnosis of liver cancer with ten-phase combination were 96.25%,96.57%,96.49%, 3.75%and 3.43%respectively;nine-phase were 96.25%,96.57%,96.49%,3.75%and 3.43%respectively;eight-phase were 93.75%,96.57%,95.85%,6.25%and 3.43% respectively;six-phase were 96.25%,96.57%,96.49%,3.75%and 3.43%respectively; four-phase were 92.50%,94.85%,94.25%,7.50%and 5.15%respectively; three-phase were 88.75%,92.27%,91.37%,11.25%and 7.73%respectively.(2)The diagnosis of liver cancer with multi-phase combination through ROC:Area under curves was 0.985(p=0.000) for ten-phase combination,0.984(p=0.009) for nine-phase,0.980(p=0.009) for eight-phase,0.983(p=0.009) for six-phase,0.969 (p=0.000) for four-phase and 0.955(p=0.000) for three-phase.(3) The sensitivity,specificity,accuracy,false negative rate and false positive rate in diagnosis of regenerative nodules or dysplastic nodular lesions of liver with ten-phase combination were 93.10%,98.59%,98.08%,6.90%and 1.41%respectively; nine-phase were 86.21%,98.59%,97.44%,13.79%and 1.41%respectively; eight-phase were 68.97%,98.59%,95.85%,31.03%and 1.41%respectively; six-phase were 96.25%,96.57%,96.49%,3.75%and 3.43%respectively;four-phase were 58.62%,97.89%,94.23%,41.38%and 2.11%respectively;three-phase were 51.72%,97.18%,92.97%,48.28%and 2.82%respectively.(4) The diagnosis of liver regenerative nodular or dysplastic nodular lesions with multi-phase combination through ROC:Area under curves was 0.980(p=0.000) for ten-phase combination,0.961(p=0.000) for nine-phase,0.921(p=0.000) for eight-phase,0.881(p=0.000) for four-phase and 0.839(p=0.000) for three-phase.Conclusions:Nodular lesions are often multiple in the liver.Ten-phase dynamic scanning is important in the detection and diagnosis of hepatic lesions,which can provide more characteristic and definite information than route three-phase or four-phase scans.(1)Enhancing at arterial peak or late arterial phase,signal attenuation at portal peak or late portal phase and persistent enhancement for two or three phases are the features of liver cancer with or without intervention treatment and other lesions with hyper-vascular.Six-phase scan including arterial peak,late phase,portal peak and late phase,balanced and delayed phase is the basic scan project for such lesions.(2)Regenerative nodular or dysplastic nodular lesions in patients with hepatic cirrhosis after hepatitis often show enhancement at early arterial and peak phase,with short enhancement and attenuation phase.Six-phase scan including arterial three phases,portal peak and late phase,and balanced one phase is important to detect those lesions.(3)Hepatic metastasis tumors with hypo-vascular were often supplied by portal vein. Multi-phase scan including arterial peak,late phase,venous three phases,balanced and delayed phase can give enough information for diagnosis. Partâ…¢Evaluation of Diffusion Weighted Imaging on Differential Diagnosis and Quantitative Diagnosis of Nodular Hepatic Lesions and Diffused Liver Lesions at 3 Tesla Magnetic ResonanceObjective:To investigate the value of Diffusion-Weighted Imaging(DWI) on differential diagnosis and quantitative diagnosis of liver diffuse lesions and nodular hepatic lesions with 3.0 T MRI.Materials and Methods:Diffusion weighted imaging(DWI) was obtained in a total of 431 cases of nodular hepatic lesions and liver diffuse lesions including normal liver, liver cirrhosis,fatty liver,hepatocellular carcinoma(HCC),cholangiocellular carcinoma(CC) and secondary tumors of liver from Apr,2007 to Mar,2008.The quality of the DWI and apparent diffusion coefficient(ADC) values were analyzed.Results:(1) The quality of DWI attenuated homogeneously according to the gradient factor(b value).There was a significant difference between the quality of b=600 and b=800 DWI(p＜0.05).(2) The ADC value of the normal liver,fatty liver,liver cirrhosis Child-Pugh A,B,C was 1.36±0.13×10-3mm2/s,1.18±0.13×10-3mm2/s, 1.32±0.11×10-3mm2/s,1.23±0.11×10-3mm2/s,1.11±0.11×10-3mm2/s respectively. There was a significant difference between normal liver tissue,fatty liver and the liver cirrhosis,(P＜0.05),and significant difference were found among Child-Pugh A,B,C (P＜0.05).(3) The ADC value of the hepatocellular carcinoma(HCC),the HCC after transcatheter arterial chemoembolization(TACE) treatment,hypovascular Hepatic Metastases,hypervascular Hepatic Metastases,cholangiocarcinoma,haemangioma, and benign lesions was 1.38±0.15×10-3mm2/s,1.42±0.21×10-3mm2/s,1.36± 0.19×10-3mm2/s,1.49±0.19×10-3mm2/s,1.44±0.12×10-3mm2/s,1.90±0.16×10-3mm2/s,1.48±0.19×10-3mm2/s respectively,and the ADC value was higher in benign lesion than that in malignant tumor.With ADC value of 1.55×10-3mm2/s as the threshold for malignant tumors and benign lesions,the sensitivity,specificity, accuracy,positive predictive value,negative predictive value,positive likelihood ratio, and negative likelihood ratio were 80.18%,81.08%,80.41%,92.71%,57.69%,4.24, 0.24,respectively.Conclusion:(1) With b value increased,the ADC value and quality of DWI decreased at the same time.According to both the value of differential diagnosis and the quality of DWI,b=600 is a free parameters in DWI scanning to get appropriate imaging on 3.0T MRI.(2) DWI is relevant to the severity of hepatic cirrhosis and fatty liver,and may be a useful quantitative tool for evaluating the severity of hepatic cirrhosis and fatty liver.(3) ADC values of malignant tumors were lower than that of benign lesions.Proper threshold of ADC value was helpful to differentiating malignant tumor from benign lesion.
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