Topological Assisted Abdominal Three-dimensional 64-slice Spiral Computed Tomographic Reconstruction In Laparoscopy-assisted Radical Gastrectomy

backgroundsince1994, Kitano etl firstly undertook laparoscopic radical gastrectomy for early gastric cancer. Compared with the traditional open operation, laparoscopic radical gastrectomy for gastric cancer with less trauma, less postoperative pain, small affect immune function, faster recovery of gastrointestinal function, shorter time of hospitalization, similar mortality in operation, complications rate, postoperative survival rate and other aspects with the caesarean operation, is More and more recognized by surgeons. In recent years, the high level of medical evidence about LAG was showing in the East.JCOG0703 confirmed the short-term clinical curative effect of laparoscopic operation for early gastric cancer. The fourth Versionof the "Japanese gastric cancer treatment guidelines" released in 2014 clearly stipulates laparoscopy as the routine diagnosis and treatment options for distal stage I gastric cancer. Focusing the long term survival and quality of life large-scale prospective, JCOG0912 and KLASS01 of South Korea are in progress, including JCOG0912 completedin 2013, which worth waiting result. Laparoscopic treatment of locally advanced gastric cancer is still controversial in Japan and South Korea, three gastric cancer, oriental country, which launched the CLASS01, JLSSG0901, KLASS02 in three large prospective randomized controlled study, look forward to in the near future to get a high level of evidence. For Laparoscopic treatment of locally advanced gastric cancer is still controversial, Japan, China and South Korea, the three gastric cancer popular country, launched the CLASS01, JLSSG0901, KLASS02, the three large prospective randomized controlled study. We can look forward to get a high level of evidence in the near future.However, in laparoscopic radical gastrectomy for gastric cancer, for lack of the direct touch of hand, it is difficult to distinguish the tissue and vascular. Compared with stereo vision in open operation, laparoscopic operation is limited by the narrow laparoscopic two-dimensional field of vision, which influenced the accuracy of space conformation judging for the abdominal organs. Furthermore, local amplification allows the operators to easily lose the whole judgment on gastric peripheral tissue adjacent to the relationship and other defects, which make it hard for Laparoscopic to anatomize celiac artery and its branches.Since 1970 three-dimensional CT reconstruction was proposed by Greenleaf JF, with the evolvement of this technology over past years, it has been generally applied to chirurgery, for example, orthopedics, neurosurgery, which plays an important role in diagnosis, illness evaluation, operational design and treatment effectiveness assessment.Unfortunately, three-dimensional CT epigastric reconstruction was restricted to vessel and parenchymal organs, subjected to the properties of epigastric organ: insignificant density variation and displacement caused by respiratory or gastrointestinal autonomic activities. restricted to the difficulty, the insignificant density variation and displacement caused by respiratory or gastrointestinal autonomic activities, an effective method for a comprehensive display of three-dimensional relationship of abdominal organs and blood vessels is absent. This inadequacy restricted the application and development of this technology, though numerous studies and experts emphasized the importance of preoperative enhancement CT and three-dimensional reconstruction to preoperative evaluation and surgical safety.Topology as a branch of mathematics can be formally defined as "the study of qualitative properties of certain objects (called topological spaces) that are invariant under a certain kind of transformation (called a continuous map), especially those properties that are invariant under a certain kind of equivalence (called homeomorphism)." Playing a unique role in image analysis and tree-dimensional reconstruction, topology is very important among various CT reconstruction methods.Because topology is an area of mathematics concerned with the properties of space that are preserved under continuous deformations including stretching and bending, but not tearing or gluing. This includes such properties as connectedness, continuity and boundary. Unaffected by the gastrointestinal autonomic activities topological analysis may reduce the error in image analysis due to individual differences in organ shape and positionFor the topological characteristic of geometry, our study analyzed CT data in topological way on the basis of traditional CT reconstruction and established the corresponding relationship among objects reconstructed and the anatomical organs. With assistance of the classic anatomy, we improved three-dimensional CT reconstruction in limited conditions.ObjectiveThe first part of this paper is to analyze the topological relationship of abdominal organ at the base of the stable front data. In the processing of 3D reconstruction, topology analyze was introduced to ensure the location of organs and vascular. Through mapping the blood vessels and comparing anatomic locations and topological relationship, we tried a new way, topological method to improve the quality of abdominal organ 3D reconstruction. The second part of the paper was to study characteristics of abdominal organs and vascular of 64 slice spiral CT scanning image; to research 3D reconstruction of arteries based on 64 slice spiral CT scanning data and thorough research on the classification of abdominal blood vessel to discussion it on the significance of laparoscopic radical operation for gastric cancer.Method1. Topology reconstruction method improves the quality of 64 slice spiral CT three-dimensional reconstruction(1) Computed Tomographic Protocol:From 2014 March to 2014 May,18 patients underwent a colonic preparation consisting of a low-residue diet, starting 3 days before CT, augmented with fasting 6 hours above and drinking 600ml water to contrast enhancement before examination. All patients underwent multiphasic CT using a 64-slice multidetector CT scanner (CTSOMATOM Definition; Siemens). The CT parameters were as follows: collimated slice thickness,0.984 mm; pitch,0.3mm; gantry rotation time of 0.4 seconds. Automatic tube current modulation was used and the reference tube-current value was 250 mA. The automated tube current modulation (ATCM, Auto mA 3D; GE Healthcare) program was used.The multiphasic, patients CT protocol consisted of precontrast, early arterial phase (AP), portal venous phase (PVP), and equilibrium phases. After the precontrast CT scan was performed, iodinated contrast medium in the amount of 370 mgl/mL (iopromide, Ultravist 370; Bayer Schering, Berlin, Germany) at a dose of 1.2 mL/kg (555 mgl/kg) per body weight was injected for 30 seconds using a power injector (Double-syringe high pressure injector; Medrad, Indianola, Pa) and was followed by an injection of 30 to 40 mL of isotonic sodium chloride solution. The timing for the AP scan was determined using the bolus tracking technique; that is, AP scanning was automatically started 5 seconds after the attenuation coefficient of the abdominal aortic blood reached 100 Hounsfield units (HUs) at 160 kV(p). Portal venous phase and equilibrium phase scanning was obtained 45 seconds and 2 minutes, respectively, after the start of contrast-medium administration.(2) Image quality evaluationTo perform quantitative evaluation, a radiologist (B.Y.H., with 5 years of clinical experience) measured the CT numbers and their standard deviations, that is, objective image noise on each image set.For each image sets, image noise was measured as the standard deviation of the pixel value from a circular or ovoid region-of-interest (ROI) (mean,40 mm2; range, 5-238 mm2) placed in a homogeneous region of the subcutaneous fat of the anterior abdominal wall.To ensure consistency, all measurements were performed 3 times at the level of the right portal vein, after which the means were calculated.(3) Topological analysis and CT reconstructionA workstation (Mimics Research 17.0, materialize N.V) was used to generate 3D models of the anatomy. The 3D reconstruction was created using the segmentation tool while the threshold criteria were adjusted to optimize anatomic detail and minimize venous contamination. Specific prescribed threshold values were not applied. With the information of topological properties, The 3D reconstruction was improved by adding more anatomy information and detail using the 3D sculpting tool (3-matic Research 9.0m, materialize N.V). Then high-attenuation structures (e.g., bone, bowel containing oral contrast material, or surgical clips) were removed using the 3D sculpting tool (Autodesk 3ds Max 2012, Autodesk, Inc.). The estimated required to perform these manipulations ranged from 5 to 8 hours for each case.2. Value of 64-MSCT Three-dimensional Reconstruction in Laparoscopic-assisted gastrectomy for advanced gastric cancer(1) study subjects:from 2012 November to 2013 December,469 cases clinical recommendations for abdominal enhanced scan were randomly selected, including 322 male cases and 147 female cases, age 5-85 years old (mean 48 years) in this study. There are Liver occupying in 149 cases (including 13 cases complicated with hepatolithiasis and 6 cases complicated with esophageal varices), simple hepatobiliary calculi in 66 cases, gastric and duodenal placeholder in 61 cases (9 cases combined hepatobiliary calculi), simple esophageal and gastric varices in 111 cases, pancreatic neoplasms in 26 cases (combined with hepatolithiasis in 2 cases of), splenic space occupying lesion in 43 cases, normal in 13 cases.(2) Original 64 slice CT scan data acquisition equipment:SIEMENS 64 slice spiral CT scanner (Germany). High pressure injector:MEDRAD dual syringe injector (American). Post-processing Image workstation:SIEMENS 64 slice spiral CT scanner StartVitred workstation.(3)Scan condition:pip voitage120KV、tube current 250mAs、every cycle 0.4s、 pitch0.984、slice thickness 5mm(4) Plain scan and Enhanced scanPlain scan:the dectector 0.5X64, slice thickness 5mm, Pitch:0.984, scan sight 40-50cm, matrix 512X512.Enhanced scan:using small dose of pre injection technology:all the examiner accept the test dose(test bolus) (4ml/s,20ml) to get the pre injection time density curve of arterial phase of small dose. After the completion of the inspection, greater dose of contrast agent (1.2ml/KG, upper 100ml) is injected through A tube, while 20ml physiological saline is injection through B tube, both injection speed is 4ml/s. MSCTP volume scanning in the arterial phase of pre injection of small dose of the peak time.(5) Image storing and processing:Transmit tomographic image to the StartVitred workstation, method of reconstruction is:① maximum intensity projection (MIP); ② Multi-Planar Reconstruction (MPR); ③volume rendering (VR). According to the above three kinds of reconstruction methods, adjust different domain values and modes, reconstruct the satisfactory 3D images. According to the system knowledge of anatomy, observe the image in the three-dimensional space as an arbitrary angle, analysis gastric peripheral arterial vessel, observe gastric peripheral artery display case and morphological differences. Two experienced radiology physician analyzed all the vascular reconstruction and reached consensus, if no agreement is reached, take the advice of the third radiologist. Arterial structural variation according to Michel’s classification and Ichirota lino classification standard, and then the analysis and classification.Result1. Topology reconstruction method improves the quality of 64 slice spiral CT three-dimensional reconstruction:Quantitative Analysis of Image Noise and CNR:We performed a matching and clustering analysis to suitable 18 cases. [AP<11.5, PVP<12.0, CNRAorta> 27.5, CNRPortal veln>9.5, CNRLiver> 5.61 was identified as screening criteria, which is based on previous experience, and we need further research to analyze the exact standards. Through the screening, the 18 cases were selected as the reconstruction objects.The number of sub-matrix we get from the each case ranges from 10 to 13. The bias exists mainly in some small blood vessels, for example, coronaria ventricul. But we found these biases did not affect discriminating the main the anatomical relationship in the subsequent analysis. Topological analysis and Three-dimensional computed tomographic (CT) reconstruction:We obtain the relationship among the sub-matrixes by connectivity analysis21 in the method mentioned before and improved the reconstruction showed presents gastric, liver, spleen, pancreas, abdominal aorta and its branches, the portal vein and its branches and position relationship. We reconstructed 5 cases, in which 4 cases reconstruction including the abdominal organs and abdominal arteriovenous, and 1 cases lacking gaster for data limitations.2. Value of 64-MSCT Three-dimensional Reconstruction in Laparoscopic-assisted gastrectomy for advanced gastric cancerBesides 5 cases for developing abnormal,3D reconstruction clearly showed the hepatic artery in 464 patients(98.9%).Because of individual differences in vascular perfusion, only part of patients with right gastric artery (n=337), the left gastroepiploic artery (n=350), right gastroepiploic artery (n=371) are clear display. The rest of the reconstruction results satisfied.Hepatic artery was clearly showed In 464 cases reconstruction. The most common branching pattern of the hepatic artery was Michel’s type Ⅰ in 346 patients (73.8%), while hepatic artery varied in 119 cases (26.1%).there are 28 cases of Michel’s type Ⅱ (6%),16 cases of type Ⅲ (3.4%),6 cases of type Ⅳ (1.3%),32 cases of type Ⅴ (6.8%), type Ⅵ was 2 cases (0.4%),2 cases of type Ⅶ (0.4%), type Ⅷ in 7 cases (1.5%), type Ⅸ 14 cases (3%),2 cases of Ⅹ type (0.4%) among the variation. There are other 9 cases (1.9%), which can’t be classified into Michel’s classification:including 2 cases which right hepatic arteryfrom the abdominal aorta, 6 cases of accessory left hepatic artery from the abdominal aorta issued, and 1 case of accessory left hepatic artery from the left gastric artery combined with right hepatic artery from a merger of abdominal aorta.The right gastric artery origin and walk were clearly showed in 337 cases reconstruction. According to classification of Ichirota lino, there are 54(11.5%) proximal (right gastric artery from the hepatic artery) cases,221 distal (47.1%) (right gastric artery from the proper hepatic artery and its branches) in case,56 (11.9%)tail type (right gastric artery from the gastroduodenal artery) cases and 6 other cases (1.2%), which including 3 cases from splenic artery and 3 cases from the superior mesenteric arteries.Conclusion1. For focusing on the topological relations between the organs, our reconstruction method would have the unique advantage on guaranteeing topological relations of organs. We would further explore the topological relations of organs and process or preview changes of these organs by topological transformation operation in the follow-up study. We establish the contact relation between topological and the anatomical relationship. Our topological method might play a particular role in analyzing position of anatomical organ. Nevertheless, the transform and analyzing are not complete until now. Further work is required to assess this arguably more pragmatic approach.2.3-D reconstruction can clearly reveal individual perigastric arteries. The anatomy of the stomach and perigastric arteries can be shown in vivo image, and can provide guidance for laparoscopic gastrectomy, might shorten the learning curve for beginners, might reduce intraoperative hemorrhage and other accidents, is a valuable preoperational examination for advanced gastric cancer laparoscopic operation.