The Diagnosis And Treatment Value Of Low-dose Imaging By Spiral Dual-source CT In Children With Superficial Vascular Anomalies

Part 1 The application of dual-source CT with high-pitch and individualized low-dose scanning parameters in children with superficial vascular anomaliesObjectThe goal of this study was to explore the imaging feasibility of dual-source CT(DSCT)with high-pitch and individualized low-dose scanning technique in children with superficial vascular anomalies(VAs).Material and MethodsThis study was approved by the institution of Shandong Medical Imaging and the informed consent was obtained from children's parents.Children of clinical or pre-ultrasound suspected VAs were collected from April 2017 to March 2018.CT examination was performed for all patients.Excluded the patients of allergy to contrast agent,poor function of heart,liver or kidney,and excluded the patients who were unable to cooperate with the examination.A total of 38 patients were included in this study,including 15 males and 23 females,with an average age of 3.1 years.All patients underwent a second-generation dual-source CT with high-pitch scan,combined with low-dose scanning protocol of 70KV tube voltage and individualized tube current setted according to patients',weight.Scanning for images of the arterial and venous phases.The image quality evaluation included objective and subjective evaluation.Referring to the measurement value of the system,the average signal-to-noise ratio(SNR)is calculated as the objective image quality evaluation.Two senior imaging physicians used double blind 5-point score method to subjectively evaluate the image quality.5 for a excellent image quality,the blood vessel and the anatomical structure is very clear,and it can be accurately diagnosed;4 for a good image quality,the blood vessel and anatomical structure is good,and it can be diagnosed well;3 for a general image quality,the blood vessel and anatomical structure can be displayed,and the diagnosis can be made;2 for a poor image quality,the blood vessel and anatomical structure is unclear,and the diagnosis is difficult.1 for no useful information obtained.And images of score 3 or higher were considered sufficient for diagnostic purposes.The consistency of the subjective score was obedient to the Kappa test,k?0.81 means to a excellent consistency,k=0.61-0.80 means to a good consistency.Single phase scan time(ST),single and total phase dose-length product(DLP)were recorded,and the effective radiation doses were calculated.ResultsThe average SNR of imaging with high-pitch and low-dose scanning protocol was 48.52±11.07.The subjective quality score of overall images were above 3 points,the average scores of the two doctors were(3.8410.50)and(3.86±0.51),respectively.And there was a excellent consistency,k=0.81.The single phase ST was(0.50±0.16)s,the single phase and total phase DLP were(10.02±3.22)mGy*cm and(27.92±9.56)mGy*cm,and the total phase ED was(0.91±0.45)mSV.ConclusionThe dual-source CT with high-pitch and individualized low-dose scan protocol can excellently imaging in children with superficial vascular anomalies.We can obtain excellent images for diagnosis and reduce the radiation dose obviously at the same time.This low-dose imaging scheme can be used for the examnation of superficial VAs in children.Part 2 The value of low-dose imaging by dual-source CT in the selection of therapeutic schemes for children with superficial vascular anomaliesObjectTo explore the value of low-dose imaging by dual-source CT in the selection of therapeutic schemes for children with superficial vascular anomalies(VAs).Materials and Methods38 children(15males,23 females,mean age of 3.1 years)collected during April 2017 to March 2018 were included in this study,who were suspected to be superficial VAs and underwent high-pitch combined with individualized low-dose imaging by CT in Shandong Institute of Medical Imaging.Excluded the patients of allergy to contrast agent,poor function of heart,liver or kidney,and excluded the patients who were unable to cooperate with the examination.The CT original axial images were transfered to the three-dimensional reformation workstation(syngo CT workplace).The three-dimensional reformation included maximal intensity projection(MIP),multiple planar reconstruction(MPR)and volume rendering(VR).Then the location,size,shape and enhancement characteristics of lesions were observed,and the adjacent anatomy were displayed by three-dimensional reformation.It was importment to show the feeding arteries and draining veins of high flow lesion.For the lesions of the extremities,we determined the extent of the lesions and whether they were accompanied by changes in the adjacent bone.For the lesions located in maxillofacial region,we determined whether the lesions involve the intracranial structure and have the blood supply of the intracranial vessels.Images were diagnosed by two senior imaging physicians basing on CT original axial and reformation images.Clinicians choosed the appropriate treatment according to the characteristics of the lesions,and we followed up the clinical treatment.ResultsAltogether 45 lesions were identified in 38 children.24 high flow VAs,including 11 with hemangioma and 13 with arteriovenous malformation.14 low flow VAs,including 12 with venous malformation and 2 with lymphatic malformation.Among the 11 patients of hemangioma,3 were treated with proprolol,5 were treated with intraductal interventional embolism,and 3 were resected surgically.Among the 13 patients of arteriovenous malformations,6 were treated with intraductal interventional embolism,4 with were treated with percutaneous sclerosing embolism,and 3 were treated with resection after sclerosing.14 low flow VAs were all treated with percutaneous sclerosing embolism.For 11 patients treated with intraductal interventional embolism,the diagnostic results of CT were agreement with DSA,and the accuracy was 100%.For 6 patients treated with resection,the diagnostic results of CT were consistent with the pathology,and the accuracy was 100%,as well.ConclusionAs a fast and effective imaging examination,low-dose imaging by DSCT not only can distinguish the high and low flow lesions,but also had more advantages in the details of the lesions,especially in the display of small arteriovenous vessels.Combined with CT three-dimensional reformation technology,it can display the vascular details and anatomical characteristics of the lesions more stereoscopically and intuitively,which was of great importantance in guiding the choice of clinical treatment plan.