Application Of DWI And DCE MRI Sequences For Normal Sacroiliac Joint Imaging Performance

ObjectiveExplored the best b-value of MRI DWI sequences in displaying the sacroiliac jointsand to get the normal range of the ADC value in best b-value.Calculated DCE-MRI sequences Fenh, Senh and Tmax values and to clear the TICcurve type and fortification in normal sacroiliac joint region.Investigated the correlation between ADC and Fenh, Senh values and doublequantified the normal sacroiliac joints,and to research application value of normalsacroiliac joints between MRI DWI and DCE-MRI sequences.Materials and MethodsScaned diffusion weighted imaging (b=0,400,600,800,1000) in65healthy volunteerssacroiliac joint, male32cases, female33cases, at different b values measured ADC valueof sacroiliac joint marrow area (iliac side、sacral side) in65healthy volunteers, comparedwith the difference of the mean ADC value of the sacroiliac joint bone marrow in65healthy volunteers, Statistical comparison using one-way ANOVA, P<0.05was statistically significant for the existence of differences. Selected randomly21volunteers (13males,8females) to do DCE-MRI scanning in sacroiliac joint and used GE processingworkstation MRAW4.6to plot the TIC curve, calculated the value of the enhanced factorFenh and the enhanced slope Senh from the measured data, used one-way ANOVA to dostatistical comparative analysis on calculated Fenh, Senh value and peak time Tmax valuesand determined the type of TIC curve, cleared the fortification and perfusion situation inthe bone marrow region of sacroiliac joint. Used Spearman rank correlation to analyze therelationship of ADC values with Fenh, Senh values and to define the correlation of themand to do double quantization in the bone marrow region of sacroiliac joint. ResultsIn65healthy volunteers sacroiliac joint bone marrow region, when it was b=400s/mm2,the mean ADC value (×10-4mm2/s) were right iliac side (3.506±0.968), left iliacside (3.453±0.936), right sacral side (3.355±0.886) and left sacral side (3.381±0.908);when it was b=600s/mm2, they were right iliac side (3.472±0.441), left iliac side(3.402±0.425), right sacral side (3.272±0.398) and left sacral side (3.249±0.401); when itwas b=800s/mm2,they were right iliac side (3.409±0.461), left iliac side (3.367±0.463),right sacral side (3.301±0.374) and left sacral side (3.279±0.385); when it was b=1000s/mm2, the image is blurred due to the SNR decline so that the selected region ofinterest clearly will not be able to complete the measurement of ADC value. when theywere b=400,600,800s/mm2, the differences of the measured ADC values in bilateralsacroiliac joint bone marrow region were not statistically significant (P>0.05); themeasured ADC values in bilateral sacroiliac joint bone marrow region was more accuracyin600,800s/mm2than that in400s/mm2, it displayed much clearer intuitive and bettercontrast in600s/mm2than that in800s/mm2on the sacroiliac joints and surroundingtissues、structures such as muscles、bones,etc. when it was b=600s/mm2, the differences ofthe measured ADC values on both sides of the sacroiliac joint bone marrow region werenot statistically significant (P>0.05).Done DCE-MRI scanning in21healthy volunteers,42sacroiliac joints, the TIC curvehad three types,4iliac side,3sacral side of bone marrow region were in typeⅠ,34iliacside,36sacral side of bone marrow areas were in type Ⅲ,4iliac side,3sacral side ofbone marrow areas were in typeⅡ;the mean value of Fenh and Senh value in theiliac,sacral bone marrow region of the sacroiliac joint were within20%<Fenh<90%and10%min<Senh<40%min, to indicate sacral iliac bone area perfusion and vary difference,the differences of the derived variables Fenh, Senh and Tmax values on left and right sidesand the iliac, sacral bone marrow region of the sacroiliac joint were not statisticallysignificant(P>0.05);4iliac side,3sacral side of bone marrow areas were no way tostrengthen,38iliac side,39sacral side of bone marrow areas were mild enhancementmode,42sacroiliac joint bone marrow region were no heavy fortification.There was a a positive correlation between ADC value and Fenh value in bonemarrow region sacroiliac joint of21healthy volunteers, linear correlation coefficientvalues between ADC value and Fenh value was rs=0.356; while no linear correlationbetween ADC value and Senh value, linear correlation coefficient values between ADCvalue and Senh value was rs=0.153. ConclusionThe results of this study showed the best b value of MR-DWI sequence that displayed thesacroiliac joint was600s/mm2, the normal range of the mean ADC value(×10-4mm2/s) onsacroiliac joint area were iliac side (3.437±0.434), sacral side (3.260±0.399). Analyed therange of the calculated Fenh, Senh and Tmax values in DCE-MRI sequence,to know theblood flow perfusion and vary difference in healthy volunteers sacroiliac joint bonemarrow region. its main modes were non-enhancement and mild enhancement, there werethree types on time-signal intensity curve (TIC curve), the bone marrow area was major intype Ⅲ. There was a a positive correlation between ADC value and Fenh value in bonemarrow region sacroiliac joint and no linear correlation between ADC value and Senhvalue.normal sacroiliac joints were semi-quantitative analysis, the studied sequencesprovided a normal group to early diagnosis and subsequent treatment of ankylosingspondylitis.