| Objective:To investigate the clinical value of intra-abdominal hernia on typing, grading with multi-slice spiral CT (MSCT). Materials and Methods:30patients were confirmed by surgery with intra-abdominal hernia, their clinical and imaging datas were retrospectively analyzed, including typing and grading results with MSCT compared to the surgical and pathological findings.Results:①Based on surgical findings, the incidence rates’of all kinds of intra-abdominal hernias, including foramen of Winslow hernia, paraduodenal hernia, intra-abdominal hernia due to banded adhesions, transmesenteric hernia, transomental hernia, the omentum hiatal hernia, anastomotic hernia after gastrectomy, pericecal hernia, hernia through the broad ligament and hernia through the Douglas fossa, were3%,23%,40%,7%,3%,3%,10%,7%,4%. Paraduodenal hernia was the most common type of congenital intra-abdominal hernias, while intra-abdominal hernia due to banded adhesions was the most common type of acquired ones.(2)The diagnostic accuracy of intra-abdominal hernias with CT was66.7%(20/30), and the accuracy rate of typing was53.3%(16/30). Among them, CT diagnostic accuracy rate was100%, and CT typing accuracy was81.1%(9/11) in Winslow hernia, paraduodenal hernia and pericecal hernia; But it was easy to misdiagnosis and missed diagnosis as closed loop small bowel obstruction for intra-abdominal hernia due to banded adhesions. ntra-abdominal hernia due to banded adhesions compared with traditional intra-abdominal hernia, ectopic accumulation of small intestine sign and sac-like pouch sign was often seen in the latter; closed loop sign was often seen in the former; As far as CT signs of strangulation were concened, the diagnostic results of both was similar.④In main CT signs of intra-abdominal hernia, the appeared rates of ectopic accumulation of small intestine sign, sac-like pouch sign, closed loop sign, target sign, whirl sign and bloody exudate sign were respectively70.0%,33.3%,56.7%,53.3%,20.0%,43.3%, which maybe regarded as positioning, quantitative and qualitative evaluation method for the establishment of diagnostic procedures.⑤transposition between small intestine and colon sign or transposition beween omental and adipose sign was one of special manifestations for ectopic accumulation of small intestine sign; Clustered distribution sign or mushroom-shaped sign was respectively one of early manifestations for sac-like pouch sign or closed loop sign; sac-like pouch sign was a special type of closed loop sign, it was also the unique typical signs of intra-abdominal hernia.⑥In all cases of intra-abdominal hernia, the accurate rate of staging with CT was83.3%(25/30), which was consistent with the surgical findings (Kappa=0.759, Z=5.000, P<0.05). Conclusion:Intra-abdominal hernia due to banded adhesions is an important complement for intra-traditional abdominal hernia on typing and epidemiology. It is valuable in assessment of the common pathological basis, main CT signs as well as grading of intra-abdominal hernia with MSCT for guiding the surgical programs. THE APPLICATION OF DUAL-SOURCE CTA SHOWING SUPERIOR MESENTERIC ARTERY DISEASESObjective:To investigate the clinical value of dual-source CT angiography(DSCTA) in diagnosis of superior mesenteric artery(SMA) diseases. Materials and Methods:91patients with suspected acute mesenteric ischemia(AMI) underwent dual energy (DE) sequence scanning with DSCT, compared with the results of digital subtraction angiography(DSA), intravascular catheter thrombolysis therapy and surgical vascular incision embolectomy. Among them, a total of60cases was regarded as a experimental group or DE group, excluding the condition of severe calcification, severe stenosis and incomplete image of SMA.60patients with suspected abdominal disease during the same period underwent conventional scanning with DSCT was treated as a control group or NDE group. The images of SMA and abdominal aortic(AA) were reconstructed with multi-planar reconstruction (MPR), maximum intensity projection (M1P), volume rendering (VR) and curved planar reconstruction (CPR). The region of interest (ROI):Area1, vertical segment with AA. Area2, parallel segment with AA. Area3, conical segment. Objective evaluation:Signal to noise ratio (SNR)=CT value of vascular/standard deviation (SD) values of vascular. Contrast to noise ratio (CNR)=(CT value of vascular-CT value of waist muscle)/SD value of air. Subjective scoring:The imaging quality was classified into four grades:score0with obvious blurred edges and artifacts, which could not be used to diagnose; score1with moderate blurred edges of SMA and artifacts; score2with slightly blurred edges of SMA and mild artifacts; score3with clear edges of SMA and without artifacts. The radiation dose calculation:volume ct dose index(CTDIvol) and the dose length product(DLP) were automatically generated by the machine after scanning, DLP=CTDIvol×L (scanning length); effective radiation dose (ED)=DLP×k(abdomen conversion coefficient). Then, the Impact of thickness and voltage on the image quality of the DE group was evaluated, and subjective scoring and radiation dose of DE group were compared with NDE group. Results:①In DE group, the images with layer thickness of5mm compared with those of1.5mm, SNR and CNR of the former in three ROIs were higher to the latter.②In DE group, the images with tube voltage of100kv compared with those of140kv, SNR of the former in ROI1and ROI2, were higher to the latter, while there was no significant difference for SNR in ROI3between two series of images, because the blood vessels are too small to produce measurement errors. CNR in the evaluation of image quality, compared with the SNR, subject to less influence of measurement errors.③As far as the baseline characteristics between DE group and NDE group were concerned, including gender, age, body mass index and scan range, there was no statistically significant difference; Although subjective scoring result of DE group was similar and that of NDE group, compared to the latter, the former reduced the radiation dose of more than50%(including unenhanced and arterial phase).④By the analysis of onset time, there were two incidence peaks in period of both March to May and September to December, with the highest morbidity rate in December.⑤By the analysis of etiology, there were16cases of developmental variation, including6cases of SMA syndrome and10cases of abnormal blood vessels; Thrombosis and embolism were the most common, the latter could lead to strangulated intestinal obstruction(SIO);There were18cases of dissection and6cases of aneurysms; Peripheral violations include eight cases involving the SMA, while two cases involving SMA and SMV.⑥By the analysis of small bowel obstruction(SBO) caused by SMA thrombosis or embolism, there were8cases who had occurred intestinal ischemic or necrosis,3cases without ischemic or necrosis and4cases missed or misdiagnosed. Conclusion:Through the objective evaluation and subjective scoring of three ROIs in different groups, Changing parameters enabled dual-source CT to optimize image quality; SMA diseases were critical, DSCTA with DE sequence scanning greatly reduced processing time and radiation dose, so that both doctors and patients could benefit from them. |
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