HU In Aorta Research Articles

Impact of Pancreaticoduodenectomy on Remnant Pancreas Vascular Enhancement Patterns: Raising the Specter of Pancreatic Recovery

Introduction: Pancreatic cancer is well recognized to cause changes in the non-tumoral pancreatic parenchyma. The aim of this investigation was to examine the impact of pancreaticoduodenectomy on postoperative pancreatic parenchymal enhancement patterns. Methods: Consecutive patients who underwent pancreaticoduodenectomy for IPMN or non-IPMN associated pancreatic adenocarcinoma were selected. ROIs were selected in the proximal pancreatic bod. The pancreatic values were normalized to the HU in aorta and porta vein. Median values with standard deviations were calculated and ratios were compared by two tailed Student’s t-testing. Results: A total of 85 patients were included (38 with adenocarcinoma, 47 with IPMN and IPMN associated cancer). No patients had chronic pancreatitis and 19% received neoadjuvant therapy. There was improvement in arterial pancreatic parenchymal enhancement postoperatively (0.33 to 0.44 normalized HU ratios, p<0.0001) with 63% of patients improving in arterial enhancement(0.85 ± 0.5 normalized HU ratio), and venous kinetic enhancement pattern (0.64 to 0.58, P=0.02). When patients were stratified into those who had normal vs abnormal kinetic enhancement preoperatively, no differences were seen in the postresection enhancement values (see Table). Among those with an abnormally enhancing gland preop, 85% had improvement, with significantly higher improvement than those with normal gland. Conclusions: After pancreaticoduodenectomy, there is a measurable improvement in pancreatic enhancement patterns on axial imaging. The improvement in the briskness of arterial enhancement is even more marked in those who have an abnormal parenchymal pattern preoperatively. These data suggest the possibility of some amount of parenchymal recovery for the remnant gland after pancreaticoduodenectomy.

복부 CT 검사 시 이중에너지 기법을 통한 적정한 조영제 양에 관한 연구

이중에너지 기법을 이용한 복부 CT 검사에서 적정한 조영제 양에 대하여 알아보고자 하였다. 일반적인 단일에너지 복부 CT 검사를 시행했던 환자들 중 이중에너지 기법을 이용하여 추적검사를 시행한 30명을 대상으로 하였다. 단일에너지 복부 검사에서 사용했던 조영제 양 대비 30%, 40%, 50%, 60%, 70%로 각각 설정하여 영상을 획득한 후 대동맥, 하대정맥, 간문맥, 간실질에 관심영역을 설정하여 조영증강정도(hounsfield unit; HU)를 구하여 단일에너지에서 측정된 부위와의 값을 비교 분석하였다. 그 결과 기존대비 60%로 조영제를 설정한 군에서는 대동맥 HU : <TEX>$210.80{\pm}13.609$</TEX>, 하대정맥 HU : <TEX>$190.40{\pm}25.215$</TEX>, 간문맥 <TEX>$198.40{\pm}21.232$</TEX>, 간실질 HU : <TEX>$119.20{\pm}7.98$</TEX>로 각각 측정되었으며. 단일에너지 복부 CT 검사는 대동맥 HU : <TEX>$205.40{\pm}16.426$</TEX>, 하대정맥 HU : <TEX>$188.20{\pm}21.476$</TEX>, 간문맥 HU : <TEX>$195.40{\pm}22.744$</TEX>, 간실질 HU : <TEX>$121.00{\pm}6.595$</TEX> 이었다. 따라서 이중에너지를 이용하여 복부 조영 CT검사를 시행할 때 조영제의 양을 60%로 설정한 후 검사하는 것이 각 장기에서의 단일에너지 조영검사시와 비슷한 조영증강정도를 획득할 수 있어 기존 조영제 양의 감소와 동시에 조영제를 낮은 속도로 주입할 수 있어 신장기능 저하환자, 정맥혈관이 약한 환자, 과거 조영제 부작용이 있었던 환자에게 유용한 검사라 사료된다. The purpose of this study is finding optimum contrast medium quantity during abdominal CT using dual energy technique. The study subjects are 30 patients who had received general single energy abdominal CT and received double energy technique follow-up abdominal CT. dual energy technique abdominal CT images were obtained after setting contrast medium quantities at 30%, 40%, 50%, 60% and 70% of contrast medium quantity at the time of single energy technique. Then the contrast enhancement (Hounsfield Unit; HU) was estimated by setting-up the regions of interest at aorta, inferior vena cava, hepatic portal vein and hepatic parenchymal. The obtained values were compared to the values of the same parts measured during single energy technique abdominal CT. The results of the study were as following. The 60% set up group had HU in aorta : <TEX>$210.80{\pm}13.609$</TEX>, IVC : <TEX>$190.40{\pm}25.215$</TEX>, hepatic portal vein : <TEX>$198.40{\pm}21.232$</TEX> and hepatic parenchymal : <TEX>$119.20{\pm}7.98$</TEX>, The single energy abdomianl CT images had HU in aorta : <TEX>$205.40{\pm}16.426$</TEX>, IVC : <TEX>$188.20{\pm}21.476$</TEX>, hepatic portal vein : <TEX>$195.40{\pm}22.744$</TEX> and hepatic parenchymal : <TEX>$121.00{\pm}6.595$</TEX>. Therefore, it is possible to obtain contrast enhancement by dual energy technique abdominal CT similar to the same by single energy technique abdominal CT by setting-up the quantity of contrast medium at 60% of contrast medium at the time of single energy technique abdominal CT. Based on the result of this study, it is possible to decrease existing quantity of contrast medium by _% and the injection velocity can be also decreased. Accordingly, it is believed that the result of study would be quite useful for patients who have renal function disorder, weak vein or side effect of contrast medium in the past.