| First part Study of ADC value of cirrhotic liver and its correlation with liver functionPurposeTo discuss the best b value range of diffusion-weighted imaging(DWI)in liver and the reason of Apparent diffusion coefficient(ADC)value changed in hepatic cirrhosis, and to explore the relationship between the ADC value and Child-Pugh score.Methods and MaterialsAll images were performed in 3.0T supraconduction MR scanner(Philips Achieva 3.0T),using 6 channels SENSE Torso body coil.Diffusion-weighted imaging of 20 healthy volunteers and 19 cirrhotic patients were scanned with 6 b value(0,200,400, 600,800,1000s/mm2).ADC maps were made by 2 b value DW imaging sequence such as b(0,200 s/mm2),b(0,400 s/mm2),b(0,600 s/mm2),b(0,800 s/mm2),b(0,1000 s/mm2).The ADC values were measured in three places of liver in five ADC maps,the means were calculated and named ADC1,ADC2,ADC3,ADC4,ADC5. Child-Pugh score were calculated in 19 cirrhotic patients.Comparisons of ADC values were performed in different b values,and between the normal and the cirrhotic patients. Correlations between ADC values and Child-Pugh score grade and scores in different b values were performed.Results①From 20 healthy volunteers,we found,when b value increased,hepatic signal intensity,tissue resolution and ADC value descend,and at the same time,the ADC value became steady.②The normal hepatic ADCs in low b value were higher than those in high b value.ADCs between cirrhotic and normal liver were significant difference when the b value was 200,400 s/mm2.When b value was 200 s/mm2,normal liver ADC value was 2.360±0.445×10-3mm2/s,cirrhotic liver was 2.174±0.516×10-3mm2/s.As b value was 400 s/mm2,they were 1.867±0.473×10-3mm2/s and 1.632±0.451×10-3mm2/s.③ There were 7 of 19 cirrhotic patients with liver function of Child-Pugh A grade, Child-Pugh B grade were 6 and another 6 were Child-Pugh C grade.No significant correlations were observed between Child-Pugh score grade and ADCs.④The coefficient of correlation(r)between Child-Pugh score and ADCs were -0.2398,0.2091, 0.3277,0.3267,0.0522,the P values were lager than 0.05.Conclusion①When b value 600～800s/mm2 was used,clear imaging and steady ADC value can be acquired,and b value should be lower than 400 s/mm2 when it is necessary to diagnose hepatocirrhosis.②ADC value can diagnose hepatocirrhosis,and its descending may caused by decreased blood perfusion in cirrhotic liver.③The ADC value may have little help to evaluate the function of cirrhotic liver.Second part Evaluate DWI ADC value in diagnosis of the dysplastic nodule and small hepatocellular carcinomaPurposeTo dicuss DWI ADC value in diagnosing dysplastic nodule(DN)and small hepatocellular carcinoma(sHCC)in cirrhotic liver.Methods and MaterialsT1WI,T2WI,DWI(b value was 0,600 s/mm2)and Gd-DTPA-enhanced MR imaging were performed in 50 cirrhotic patients.The signal intensity of DN and sHCC was detected in the DW imaging with b value 0 and 600s/mm2,and the ADC values were calculated by the detected signal intensity.Comparison of the ADC value between DNs and sHCCs were performed. ResultsThere were 7 DNs and 8 sHCCs were found in 50 cirrhotic patients.DNs were homogeneous high signal intensity in T1-weighted imaging,low signal intensity in T2-weighted imaging and DW imaging,almost same intensity in different phase of GD-DTPA enhanced imaging,sHCCs were low signal intensity in T1-weighted imaging, inhomogeneous high signal intensity in T2-weighted imaging and DW imaging,they were enhanced in arterial phase,became low signal intensity in delayed phase.The ADC values of DNs were 1.276±0.467×10-3mm2/s,and sHCCs were 0.833±0.076×10-3mm2/s. There was significant difference between them.ConclusionMagnetic resonance DW imaging can be a routine abdominal MRI sequence in diagnosing hepatic nodules.The ADC value of DN is higher than sHCC,ADC value show helpful to distinguish DN and sHCC.
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