Corona Mortis:The Application With Volume Helical Shuttle Of CT Scan And CTA Anatomy

Objective: Contrast CT volumetric spiral shuttle technique and CTA blood vessel display rate in CTA arteriovenous two-phase scan;Contrast between intraoperative CMOR vascular discovery rate and CTA blood vessel display rate in CTA volumetric spiral shuttle technique,analysis of preoperative CTA examination Clinical significance.Anatomical typing and measurement of CMOR vessels provides an imaging basis for the clinic.Materials and Methods: A total of 139 patients with pelvic CTA images were collected from patients who underwent pelvic CTA examination in Tianjin Hospital from January 20 to March 2019.Among the 138 subjects,the bilateral internal and external iliac vessels were clearly displayed.The pelvis was divided into the left and right pelvis by the median sagittal plane of the pubic symphysis.A total of 276 pelvic vessels of the semi-pelvis were obtained.According to different examination methods,the subjects were divided into two groups: group A was treated with CT volumetric spiral shuttle technique for pelvic CTA scan.The scan time ranged from early arterial to late venous,and arterial phase scan was performed using contrast tracer method.Abdominal aorta The region of interest is selected on the upper edge of the fork,and the CT value is monitored in real time.When the CT value of the region of interest reaches 200 HU(about 25 s from the injection time),the scan is started,and the arterial phase is continuously scanned 3 times.The venous phase was scanned continuously 3 times from 75-80 s after the injection of contrast agent,and a total shuttle scan was performed 6 times.In group B,two-stage arteriovenous scanning was performed.The scanning phase of arterial phase was the same as that of group A.The scanning time of venous phase was 90 s after contrast agent injection.Images of 276 unilateral pelvic vessels were analyzed by GE AW4.6 workstation.The study is divided into two parts: the first part is the value of CT volume spiral shuttle technique in the observation of "death crown";the second part is the related research of "death crown" anatomy.Statistical analysis was performed using Chi-Square Goodness-of-Fit Test and One-way ANOVA.Results:(1)VHS-CT can display dynamic and intravenous CMOR in multiple phases.The CMOR of group A was 15.5%(22/142),the rate of venous CMOR was 64.1%(91/142),the rate of CMOR in group B was 17.2%(23/134),and the rate of venous CMOR was 47.8.%(64/134);There was no significant difference in the display rate of CMOR vessels between the two groups(P>0.05).There was a statistically significant difference in the rate of venous CMOR blood vessels(P <0.05);There was a statistically significant difference in the rate of CMOR and venous CMOR between the group and the B group(P < 0.05).(2)A total of 13 cases of CMOR vessels in the semi-pelvis were observed in the operation.Among them,12 cases were consistent with CTA,7 cases were true positive,5 cases were true negative,and 1 case was false negative.The sensitivity was 85.71% and the specificity was 100%.The Kappa value in the consistency test was 0.84,indicating good agreement.(3)Type I(arterial type)accounted for 12%(21/175),type II(venous type)accounted for 74.29%(130/175),and type III(dynamic/venous mixed type)accounted for 13.71%(24/175).This study found types IIc and IIIb not reported in the literature.(4)The minimum distance between the arterial CMOR and the suprapubic branch was 1.53 ± 1.29 mm;the minimum distance between the venous CMOR and the suprapubic branch was 1.16 ± 1.32 mm.There was no significant difference in the minimum distance between different sex,left and right side,dynamic and intravenous CMOR and suprapubic branch(P>0.05).(5)The distance between the arterial CMOR and the ipsilateral pubic symphysis was 52.79±7.27 mm;the distance between the venous CMOR and the ipsilateral pubic symphysis was 56.35±11.14 mm.The difference in distance between the CMOR and the pubic symphysis was statistically significant(P < 0.05),and the distance between the venous CMOR and the ipsilateral pubic symphysis was far.(6)The arterial CMOR diameter was 2.14 ± 0.61 mm;the venous CMOR diameter was 2.50 ± 0.89 mm.Conclusion:(1)Both the VHS-CTA and the arteriovenous dual-phase scan can clearly show the arterial CMOR.The VHS technique of CT has a higher display rate of intravenous CMOR than the arteriovenous dual-phase scan.(2)Intravenous CMOR is more common in the human population than in arterial CMOR.(3)The display rate of VHS-CTA for CMOR is consistent with the CMOR found during surgery.(4)Type I(arterial type)CMOR is mainly type Ib;type II(venous type)CMOR is the most common,mainly type IIa;further classification of different subtypes helps to correctly identify CMOR.(5)The minimum distance between CMOR and suprapubic branch was not statistically different between gender and left and right sides.The distance between the venous CMOR and the pubic symphysis is farther than that of the arterial CMOR.Both arterial CMOR and intravenous CMOR are small diameter vessels.