Detection Of Sacroiliac Joint By Ultrasound/CT Fusion Imaging And Primary Application Of Blood Flow Parameters Of The First Foraminal Ramus Of The Lateral Sacral Artery In Sacroiliitis

Part Ⅰ Fusion of real-time ultrasound with CT images to detect sacroiliac jointObjectiveApplication of ultrasound/CT fusion imaging technology,real time ultrasound scanned the posterior wall of the human pelvis.To summarize the sonographic features of the posterior pelvic wall with emphasis on the sacroiliac joint,and to provide an imaging basis for the diagnosis of sacroiliitis in ankylosing spondylitis(AS).MethodsA total of 50 patients with suspected AS underwent CT scan of sacroiliac joint were enrolled.CT data were imported into ultrasound instrument,which was equipped with a magnetic navigation system.Point-plane image registration method was used to fuse ultrasound and CT images.The posterior pelvic wall was subjected to a complete cross-sectional ultrasound scan.We summarized the key operative points and the timing of sacroiliac joint fusion imaging.CT imaging was used to determine the ultrasound sectional anatomy of the posterior wall of the pelvis.ResultsFusion imaging was successful in all 50 subjects.The image fusion was performed in 2-8 minutes with an average of(4.0±0.6)minutes.Ultrasonography can show the main anatomic structures of the posterior wall of the pelvis,such as the sacrum,the ilium,the sacroiliac joint and the posterior sacral foramen.The sacrum and the ilium were hyperechoic,accompanied by acoustic shadow.The sacroiliac joint and the posterior sacral foramen were hypoechoic.According to the main structure of ultrasonic scan in different cross-sectional,the posterior wall of the pelvis can be divided into two types of image,transverse section across the posterior sacral foramen and transverse sectionbetween the posterior sacral foramen.In the former ultrasonography,two hypoechoic pores were seen,representing the posterior sacral foramen and sacroiliac joint.The posterior sacral foramen was located at the inside and the sacroiliac joint at the outside;in the latter ultrasonography,only one hypoechoic pore was seen,representing the sacroiliac joint.The sacroiliac joint was mainly located at the level between the first posterior sacral foramen and the second posterior sacral foramen.In some patients the sacroiliac joint was still visible at the third posterior sacral foramen.ConclusionThe posterior wall of the pelvis can be successfully detected by ultrasound and CT fusion imaging.CT images are helpful for the recognition of bony structures by ultrasound.The location and sonographic features of the sacroiliac joint and the posterior sacral foramen show obvious characteristics,and ultrasound detection has higher accuracy.Part Ⅱ Anatomical and Doppler ultrasonographic study of the first foraminal ramus of the lateral sacral arterySection ⅠAnatomical study of the first foraminal ramus of the lateral sacral artery ObjectiveTo confirm the first foraminal ramus(FFR)of the lateral sacral artery is the supply artery of the sacroiliac joint by anatomy.The aim of thisstudyis to provide a theoretical basis for the clinical application of the FFR blood flow parameters for the evaluation of sacroiliitis.MethodsA total of 12 FFRs of the lateral sacral artery were studied in 6 adult cadavers.The anatomy of the bilateral posterior sacral region was performed.The blood vessel and its branches are separated,and the origin,course,branch and caliber of the blood vessel were recorded.Results1.The origin and number of the lateral sacral arteryOf the 12 lateral sacral arteries,7 originated from the internal iliac artery,3 from the inferior gluteal artery,and 2 from the superior gluteal artery.Each lateral sacral artery had 1-3 branches.8 cases had 2 branches,which was the most common situation.2.The course and branches of the FFRThe lateral sacral artery had two branches,the FFR originated from the upper branch and entered the first sacral foramen.In 11 cases,it sent out three branches.A branch went laterally into the lateral nutrient foramen of the sacrumattached to the back of the sacrum,supplying the lateral sacral bone(sacral branch).The second branch extended to the superficial muscles(muscular branch).The third branch went medially and into the vertebral body(spinal branch).In one case,the FFR had only two branches,the sacral branch and the spinal branch.3.The average diameter of the FFR was(1.46±0.15)mm.ConclusionThe FFR originated from the upper branch of the lateral sacral artery,went through the first sacral foramen and branched out of the posterior sacral foramen,one of which supplied blood for the lateral sacral.Section ⅡDiagnostic value of sacroiliitis for Doppler sonography detecting the first foraminal ramus of the lateral sacral arteryObjectiveThe purpose of the research is to study methodology of ultrasonography of FFR of the lateral sacral artery and to investigate the diagnostic value of its blood flow parameters for sacroiliitis in patients with ankylosing spondylitis(AS).MethodsEighty cases of active ankylosing spondylitis were selected as the patient group and 50 healthy subjects as control group.Doppler ultrasound detected both FFR in each subject.The observation indexes included systolic peak flow velocity(PSV),end diastolic flow velocity(EDV),resistance index(RI)and pulsatility index(PI).The reproducibility of the measurements was analyzed by repeated measurements of 30 volunteers from two ultrasound physicians.The hemodynamic parameters of the FFRwere comparedbetween two sides and different genders in control group.Hemodynamic parameters were also compared between case group and control group.ResultsThe age,sex and body mass index were not statistically different between the case group and the control group.The FFR was successfully detected by Doppler ultrasonography in all subjects except for one obese patient.Gray scale sonography failed to show the FFR.According to the anatomical findings,the first posterior sacral foramen with low echogenicity in the transverse sonogram was used as landmarks of the vessel.The intraclass correlation coefficient of the hemodynamics measured by two physicians was between the 0.80-0.88,which indicated good repeatability.In control group,the mean PSV of the FFR was(29.3±4.1)cm/s;the mean EDV was(5.3±1.1)cm/s;the mean RI was 0.82±0.04;the mean PI was 2.94±0.65.The differences of PSV,EDV,RI and PI between different genders and both sides were not statistically significant(P>0.05).Between case group and control group,there was no statistically significant difference in PSV,but there was a statistically significant difference in EDV,RI and PI(P < 0.05).ConclusionThe FFR of the lateral sacral artery can be detected by Doppler sonography at the first posterior sacral foramen.In the normal population,the FFR showed high resistance blood flow spectrum.In patient with active sacroiliitis,the RI and PI were decreased significantly.Blood flow parameters contribute to the diagnosis of sacroiliitis.Part Ⅲ The value of Doppler ultrasonography in detecting the first foraminal ramus of the lateral sacral artery in the treatment of sacroiliitisObjectiveTo analyse the change of hemodynamic parameters of FFR of the lateral sacral artery in active sacroiliitis patients with etanercept treatment and to investigate the value of ultrasound in detecting the blood vessel in the treatment of sacroiliitis.MethodsFifty patients were included in the study.They all fulfilled the modified New York classification criteria for AS.All patients were in the active phase of disease.Bath AS disease activity index(BASDAI)> 4.All the patients underwent 12 weeks of etanercept treatment.The blood flow parameters of the FFR(PSV,EDV,RI and PI)were detected by Doppler ultrasonography before and 12 weeks after treatment.BASDAI,Bath AS disease function index(BASFI),Bath AS disease measurement index(BASMI),visual analogous scale(VAS)of night back pain and general back pain,time of morning stiffness,erythrocyte sedimentation rate(ESR)and C reactive protein(CRP)before and after treatment were recorded.ResultsThere were 45 males and 5 females in the study,with an average age of(28.4±8.7)years,with an average duration of(4.8±4.1)years,with an average BMI of(22.1±5.2)kg/m2.HLA-B27 was positive in 46 cases,accounting for 92%.ESR increased in 47 cases,mean(45.2±32.6)mm/h;CRP increased in 49 cases,mean(26.5±18.4)mg/l.All subjects completed 12 weeks treatment of etanercept.After treatment,the PSV and EDV were not significantly changed(P > 0.05),RI and PI were significantly higher than those before treatment,the difference was statistically significant(P < 0.05).BASDAI,BASFI,BASMI,VAS of night back pain and general back pain and time of morning stiffness were improved significantly compared with those before treatment(P < 0.01).ESR,CRP levels decreased significantly than those before treatment,there were significant differences(P < 0.01).The change of RI was negatively correlated with the change of BASDAI after treatment,with a correlation coefficient of-0.56(P=0.02).The change of PI was negatively correlated with the change of BASDAI,with a correlation coefficient of-0.58(P=0.02).Conclusion1.After 12 weeks Etanercept treatment in patients with active AS,RI and PI of FFR were significantly higher than those of before treatment.These hemodynamic parameters can be used as a reference index of treatment.2.After 12 weeks Etanercept treatment,there were negatively correlated between the change of BASDAI and the change of RI and PI.3.Etanercept in the treatment of active AS patients is safe.