Predicting the image quality of respiratory-gated and breath-hold 3D MRCP from the breathing curve: a prospective study.

OBJECTIVES: To compare the image quality of breath-hold magnetic resonance cholangiopancreatography (BH-MRCP) and respiratory-gating MRCP (RG-MRCP), and to explore breathing curve-based factors and patient-related data affecting image quality. METHODS: A total of 126 participants who underwent RG-MRCP and BH-MRCP on a 3-T magnetic resonance (MR) scanner were enrolled from May to December 2021. The images were evaluated by three radiologists on a 5-point scale. Respiratory parameters were extracted from the breathing curves. The Wilcoxon test was used to compare the image quality between the two MRCPs. Logistic regression analyzes were performed to identify age, sex, abdominal pain, and breathing predictor variables of better image quality. RESULTS: BH-MRCP performed better in visualizing intrahepatic bile ducts and overall image quality than RG-MRCP (p < 0.01). Factors predicting relatively good image quality included lower standard deviation of the respiratory amplitude (SDamp)-minimum-peak (odds ratio = 0.16, p < 0.01) for RG-MRCP and lower SDamp (OR = 0.69, p < 0.01) for BH-MRCP. CONCLUSIONS: BH-MRCP had significantly better overall image quality than RG-MRCP. Respiratory conditions exerted a significant impact on MRCP image quality, and parameters derived from the breathing curve could help predict the image quality of both sequences. KEY POINTS: • Both breath-hold (BH) and respiratory-gating (RG) MRCP demonstrate satisfying image quality. • BH-GRASE-MRCP is significantly better than RG-MRCP at the group level, but not for every individual. • Respiratory conditions exert a significant impact on the image quality, and the breathing curve can help predict the image quality.

The Atlas of the Inferior Mesenteric Artery and Vein under Maximum-Intensity Projection and Three-Dimensional Reconstruction View.

(1) Background: Understanding vascular patterns is crucial for minimizing bleeding and operating time in colorectal surgeries. This study aimed to develop an anatomical atlas of the inferior mesenteric artery (IMA) and vein (IMV). (2) Methods: A total of 521 patients with left-sided colorectal cancer were included. IMA and IMV patterns were identified using maximum-intensity projection (MIP) and three-dimensional (3D) reconstruction techniques. The accuracy of these techniques was assessed by comparing them with surgical videos. We compared the amount of bleeding and operating time for IMA ligation across different IMA types. (3) Results: Most patients (45.7%) were classified as type I IMA, followed by type II (20.7%), type III (22.6%), and type IV (3.5%). Newly identified type V and type VI patterns were found in 6.5% and 1% of patients, respectively. Of the IMVs, 49.9% drained into the superior mesenteric vein (SMV), 38.4% drained into the splenic vein (SPV), 9.4% drained into the SMV-SPV junction, and only 2.3% drained into the first jejunal vein (J1V). Above the root of the left colic artery (LCA), 13.1% of IMVs had no branches, 50.1% had one, 30.1% had two, and 6.7% had three or more branches. Two patients had two main IMV branches, and ten had IMVs at the edge of the mesocolon with small branches. At the IMA root, 37.2% of LCAs overlapped with the IMV, with 34.0% being lateral, 16.9% distal, 8.7% medial, and both the marginal type of IMV and the persistent descending mesocolon (PDM) type represented 1.4%. MIP had an accuracy of 98.43%, and 3D reconstruction had an accuracy of 100%. Blood loss and operating time were significantly higher in the complex group compared to the simple group for IMA ligation (p < 0.001). (4) Conclusions: A comprehensive anatomical atlas of the IMA and IMV was provided. Complex IMA patterns were associated with increased bleeding and operating time.

[Individualized surgical treatment and prognosis of intraductal papillary mucinous neoplasms of the pancreas].

OBJECTIVE: To investigate the clinical manifestation, individualized surgical treatment, and prognosis of intraductal papillary mucinous neoplasms (IPMN) of pancreas. METHODS: The clinical data of 56 IPMN cases treated between January 2007 and December 2011 was retrospectively analyzed. Among the 56 patients (38 male and 18 female, mean age (61 ± 7) years), 26 were main-duct type, 18 were branch-duct type, 12 were mixed type. Pancreatectomy was performed on 48 cases, including pancreaticoduodenectomy on 29 patients, distal pancreatectomy on 17 patients, and total pancreatectomy on 2 patients. RESULTS: The overall postoperative morbidity rate was 27.1% (13/48), there was no perioperative mortality. Pathology showed 31 cases of noninvasive IPMN, 17 cases of invasive IPMN, and 7 cases of lymph node metastasis. The rate of invasive tumors was 46.2% (12/26) in main duct type, 3/12 in mixed type, and 2/18 in branch duct type IPMN, the difference was statistically significant (χ(2) = 6.385, P = 0.041). The five-year survival rate for patients with noninvasive and invasive neoplasms was 100% and 24.6%, respectively. The prognosis of invasive cases with lymph node metastasis was significantly worse than those without lymph node metastasis (P = 0.017). A regular follow-up without surgical treatment was performed on 8 cases with asymptomatic side branch IPMN less than 3 cm in diameter, and no progression was found during the follow-up. CONCLUSIONS: IPMN has a relative good prognosis. Main duct type and mixed type IPMN have a higher malignant potential, and should receive a surgical treatment. Patients of branch duct type IPMN with a <3 cm diameter lesion and no clinical manifestations can be managed with close follow-up only.

Automatic quantitative evaluation of normal pancreas based on deep learning in a Chinese adult population.

OBJECTIVE: To develop a 3D U-Net-based model for the automatic segmentation of the pancreas using the diameters, volume, and density of normal pancreases among Chinese adults. METHODS: A total of 2778 pancreas images (dataset 1) were retrospectively collected and randomly divided into training (n = 2252), validation (n = 245), and test (n = 281) datasets. The segmentation model for the pancreas was constructed through cascaded application of two 3D U-Net networks. The segmentation efficiency for the pancreas was evaluated by the Dice similarity coefficient (DSC). Another dataset of 3189 normal pancreas CT images (dataset 2) was obtained for external validation, including 1063 non-contrast images, 1063 arterial phase images, and 1063 portal venous phase images. The pancreas segmentation in dataset 2 was assessed objectively and manually revised by two radiologists. Then, the pancreatic volume, diameters, and average CT value for each phase of pancreas images in dataset 2 were calculated. The relationships between pancreas volume and age, sex, height, and weight were analyzed. RESULTS: In dataset 1, a mean DSC of 0.94 for the test dataset was achieved. In dataset 2, the objective assessment yielded a 90% satisfaction rate for the automatic segmentation of the pancreas as external validation. The diameters of the pancreas were 43.71-44.28 mm, 67.40-68.15 mm, and 114.53-117.06 mm, respectively. The average pancreatic volume was 63,969.06-65,247.75 mm3, which was greatest at the age of 18-38 and then decreased to a minimum at the age of 69-85. The CT value of the pancreas also decreased with age, from a maximum value of 38.87 ± 9.70 HU to a minimum of 27.72 ± 10.85 HU. CONCLUSION: The pancreas segmentation tool based on deep learning can segment the pancreas on CT images and measure its normal diameter, volume, and CT value accurately and effectively.

An individualization approach for head-related transfer function in arbitrary directions based on deep learning.

This paper provides an individualization approach for head-related transfer function (HRTF) in arbitrary directions based on deep learning by utilizing dual-autoencoder architecture to establish the relationship between HRTF magnitude spectrum and arbitrarily given direction and anthropometric parameters. In this architecture, one variational autoencoder (VAE) is utilized to extract interpretable and exploitable features of full-space HRTF spectra, while another autoencoder (AE) is employed for feature embedding of corresponding directions and anthropometric parameters. A deep neural networks model is finally trained to establish the relationship between these representative features. Experimental results show that the proposed method outperforms state-of-the-art methods in terms of spectral distortion.

Anatomical Study of the Hepatic Veins in Segment 4 of the Liver Using Three-Dimensional Visualization.

Objective: The current study aimed to examine the anatomical structure of the hepatic vein of segment IV liver (S4) of the liver using three-dimensional (3D) visualization technology in order to explore the surgical value of the middle hepatic vein (MHV) manipulation and highlight the importance of current research in hepatic surgery. Methods: Between January 2014 and December 2019, 52 patients with abdominal diseases(not including hepatic disease) were selected for multiphasic computed tomography-enhanced scans of the upper abdomen. A 3D visualization system was utilized to display the structural details of the hepatic veins in S4 of their livers. Couinaud's eight-segment classification system was used to denote the liver' sections. Results: The constructed 3D model clearly displayed vascular morphological characteristics and their location in the liver, hepatic artery and vein system, and portal vein system. Of the 52 patients, 43 had an umbilical fissure vein (UFV) (82.7%), 19 had an accessory S4 liver vein (36.5%), 16 had both a UFV (30.8%) and an accessory S4 liver vein, and 6 had neither (11.5%). A total of 79% of the patients with a UFV and 74.2% of those with an accessory S4 liver vein had venous blood returning into the left hepatic vein. Conclusion: 3D visualization technology was used to determine hepatic venous return of S4 hepatic veins and was found to improve the safety of evaluation in hepatic surgery.

Acute appendicitis complicated by mesenteric vein thrombosis: A case report.

BACKGROUND: Acute appendicitis with mesenteric vein thrombosis (MVT) is an uncommon condition and usually lacks specific clinical manifestations, which leads to a high rate of misdiagnosis or delayed diagnosis, especially when it is accompanied by other abdominal diseases. Prompt and accurate recognition is vital for treatment and prognosis. CASE SUMMARY: A 37-year-old woman had a history of acute metastatic right lower abdominal pain, nausea, and fever. A contrast-enhanced computed tomography (CT) scan showed a filling defect in the mesenteric vessels. The patient was diagnosed with acute appendicitis complicated by MVT and was treated with anticoagulation and intravenous antibiotics. The follow-up CT scan showed full resolution of the thrombosis and inflammation. CONCLUSION: Clinical awareness is essential for recognizing MVT, especially when it is accompanied by other common acute abdominal diseases, such as acute appendicitis. Contrast-enhanced CT is helpful for the diagnosis of MVT and is recommended for patients with acute abdominal diseases.

Preoperative differentiation of pancreatic mucinous cystic neoplasm from macrocystic serous cystic adenoma using radiomics: Preliminary findings and comparison with radiological model.

PURPOSE: To develop a radiomics model in the preoperative differentiation of mucinous cystic neoplasm (MCN) and macrocystic serous cystadenoma (MaSCA) and to compare its diagnostic performance with conventional radiological model. METHODS: 57 Patients (MCN = 31, MaSCA = 26) with preoperative multidetector computed tomography (MDCT) scans were retrospectively included in this study. A radiological model was constructed from radiological features evaluated by radiologists. A radiomics model was constructed with high-dimensional quantitative features extracted from manually segmented volume of interests (VOIs). A combined model was constructed using both radiomics features and radiological features. The diagnostic performance of three models were assessed by the area under the receiver-operating characteristic curve (AUC), sensitivity, specificity, accuracy, and the calibration curves. RESULTS: The radiological model yielded an AUC of 0.775, sensitivity of 74.2 %, specificity of 80.8, and accuracy of 77.2 %. The radiomics model yielded an AUC of 0.989, sensitivity of 93.6 %, specificity of 96.2 %, and accuracy of 94.7 %. The combined model yielded an AUC of 0.994, sensitivity of 96.8 %, specificity of 100 %, and accuracy of 98.2 %. Both combined model and radiomics model showed higher AUC, sensitivity, and accuracy than radiological model (all P <  .05). The combined model showed higher AUC than radiomics model, though no significant difference was found (P =  .41). The combined model showed better calibration than radiomics model (P =  .91 vs. P <  .001). CONCLUSIONS: Combined model which contained both radiomics features and radiological features outperformed radiomics model and radiological model in the preoperative differentiation of MCN and MaSCA.

The Application of Three-Dimensional Visualization in Preoperative Evaluation of Portal Vein Invasion in Hilar Cholangiocarcinoma.

OBJECTIVE: This study aimed to investigate the use of three-dimensional visualization for preoperative evaluation of portal vein invasion in hilar cholangiocarcinoma (HCCA). METHODS: This recombination study for preoperative computerized tomography images was completed in 42 patients undergoing radical resection of HCCA combined with hepatectomy. Portal vein invasion with postoperative pathology was used as a gold standard to decide if the diagnosis was correct or not. We compared the sensitivity, specificity, positive predictive value, negative predictive value, and total correctness of radiologists and a three-dimensional (3D) visualization model for the assessment of tumor-caused portal vein invasion. RESULTS: The findings for the estimation of portal vein invasion by radiologists based on CT images were as follows: sensitivity = 90.9%; specificity = 83.8%; positive predictive value = 66.7%; negative predictive value = 96.3%; and overall accuracy = 85.7%. The findings for estimation by the 3D visualization model were as follows: sensitivity = 90.9%; specificity = 96.8%; positive predictive value = 90.9%; negative predictive value = 96.8%; and overall accuracy = 90.5%. CONCLUSION: The positive predictive value of 3D visualization technology in the diagnosis of portal vein invasion is notably superior to that of subjective assessment by radiologists. This technique can thus play a significant role in preventing unnecessary resectioning of non-invaded portal veins and hepatectomy.

Application of three-dimensional visualization technique in preoperative planning of progressive hilar cholangiocarcinoma.

OBJECTIVE: This study aims to investigate the role of three-dimensional visualization technique in the diagnosis and treatment of progressive hilar cholangiocarcinoma. METHODS: From January 2014 to February 2017, a three-dimensional visualization model was set up in 23 patients with progressive hilar cholangiocarcinoma. The distributions and variations of the hepatic portal ducts were observed. The tumors were classified based on Bismuth classification. The simulation operation was performed and the operation plan was established. RESULTS: All 23 patients revealed a clear relationship between the intrahepatic and extrahepatic ducts, as well as the tumors and ducts. An individualized surgery program was established through the accurate calculation of liver volume and residual liver volume. Among these patients, 13 patients completed radical resection of hilar cholangiocarcinoma combined with massive hepatectomy. No bile leakage occurred and no operative death was found. CONCLUSION: For patients with progressive hilar cholangiocarcinoma, the optimized three-dimensional visualization technique can accurately demonstrate the dilated biliary tract system, provide a new standard to determine the presence of tumor and peripheral vascular invasion, help in establishing a reasonable individualized operation plan, reduce the incidence of bile leakage and liver failure after the operation, and improve the success rate of operation.

Three-Dimensional Measurement Applied in Design Eye Point of Aircraft Cockpits.

INTRODUCTION: Inappropriate design eye point (DEP) will lead to nonstandard sitting postures, including nonneutral head positions and other uncomfortable sitting postures, which are high risk factors for neck pain in fighter pilots exposed to high G forces. Therefore, application of a 3D measurement method to collect data regarding eye position while in the cruising sitting posture in the aircraft cockpit to guide the design eye point has been proposed. METHODS: A total of 304 male fixed wing aircraft pilots were divided into two groups. Subgroup A (N = 48) were studied to define the cruising posture during flight. Subgroup B (N = 256) were studied with Romer 3D measurement equipment to locate the cruising eye position of the pilots in a simulated cockpit. The 3D data were compared to DEP data in the current standard cockpit. RESULTS: According to 3D measurement, the vertical distance from the cruising eye point to the neutral seat reference point was 759 mm, which is 36 mm lower than that of the Chinese standard DEP and also lower than the U.S. military standard. The horizontal distance was 131 mm, which is 24 mm shorter than that of the Chinese standard. CONCLUSIONS: The current DEP data cannot fulfill the needs of fighter pilots and should be amended according to the results of the 3D measurement so that pilots can acquire the optimal cruising posture in flight. This new method has the value of practical application to investigate cockpit ergonomics and the measurement data can guide DEP design.Wang Y, Guo X, Liu Q, Xiao H, Bai Y. Three-dimensional measurement applied in design eye point of aircraft cockpits. Aerosp Med Hum Perform. 2018; 89(4):371-376.

A primary retroperitoneal anaplastic lymphoma kinase-positive anaplastic large cell lymphoma with tumor thrombosis.

Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) is a T cell subtype of non-Hodgkin's lymphoma (NHL). Typically, lymphoma rarely infiltrates vascular structure. In this article, we present a case of retroperitoneal ALK-positive ALCL with splenic venous tumor thrombosis. A 62-year-old patient presented to our institute with the symptoms of epigastric pain, abdominal distension, and reduced bowel movement. Physical examination indicated no enlarged peripheral lymph nodes or abdominal mass. Laboratory workup revealed granulocytosis, abnormal coagulation function, and normal level of lactic dehydrogenase (LDH). Contrast-enhanced computed tomography (CT) showed a retroperitoneal mass with involvement of pancreas and duodenum and formation of splenic venous tumor thrombus. Ultrasonography-guided retroperitoneal lesion biopsy confirmed the diagnosis of ALK-positive ALCL. The patient was able to tolerate oral intake after two cycles of chemotherapy and showed no sign of lymphoma by positron emission tomography (PET)-CT after the fourth cycle of chemotherapy. In spite of its rarity, lymphoma should be taken into account as a differential diagnosis of other malignancies with tumor thrombosis.

[Risk factors of anastomotic leakage after anterior resection for rectal cancer and the diagnostic value of computed tomography signs in anastomotic leakage].

OBJECTIVE: To investigate the risk factors and computed tomography (CT) diagnostic accuracy of anastomotic leakage after resection of rectal cancer (Dixon). METHODS: This retrospective study was conducted in Peking University First Hospital from January 2013 to June 2015. A cohort of 452 patients with rectal cancer was enrolled in the study. All the patients underwent anterior resection. The relationship between clinical-pathological data (including sex, age, body mass index (BMI), presence of diabetes, hypohemoglobin (Hb<90 g/L), hypoalbuminemia (Alb<35 g/L), the distance from the lower edge of the tumors to the anus, tumor diameter, tumor differentiation, tumor TNM stage, neoadjuvant therapy status, ligation of the left colonic artery(LCA), preventive colostomy, and anastomotic leakage was analyzed retrospectively. Univariate analysis using χ2 test and multivariate analysis by using the Ordered Classification Arguments Logistic regression model. RESULTS: Of all the cases, 281 and 171 patients were men and women, respectively. The median age was 64 years (range, 18-88 years). Forty-seven patients (10.4%) were diagnosed with anastomotic leakage, and the median diagnostic time of anastomotic leakage was 6.5 days(range, 3-31 days). One patient with anastomotic leakage died because of respiratory failure within 1 month postoperatively; 11 patients underwent salvage colostomy performed 2-34 days (median, 7 days) after the first surgery. All the 11 patients underwent colostomy closure within 2 years. The other 35 patients recovered by antibiotic and peritoneal lavage treatment. The mean length of postoperative hospital stay in patients without anastomotic leakage was 8.4±2.4 days, which was significantly shorter than that in patients with anastomotic leakage (34.6±15.7 days), and the difference was statistically significant (t=24.127, P=0.008). The results of the univariate analysis showed that BMI≥28 kg/m2(χ2=7.550, P=0.000), diabetes mellitus (χ2=5.055, P=0.025), Hb<90 g/L preoperatively (χ2=5.718, P=0.017), Alb<35 g/L preoperatively (χ2=8.096, P=0.004), distance of <6 cm from the lower edge of the tumors to the anus (χ2=8.205, P=0.004) and LCA ligation (χ2=16.540, P=0.000) were risk factors for the occurrence of anastomotic leakage. Multivariate analysis showed that BMI≥28 kg/m2 (OR=1.758, 95%CI: 1.265-2.454, P=0.021), distance of <6 cm from the lower edge of the tumors to the anus (OR=1.530, 95%CI: 1.035-2.117, P=0.037), LCA ligation (OR=1.551, 95%CI: 1.035-2.131, P=0.042) were independent risk factors for anastomotic leakage. The CT diagnostic sensitivity of anastomotic leakage was 91.2%(31/34). The false positive rate of CT for diagnosing anastomotic leakage was zero 7 days after the Dixon procedure. CONCLUSION: Important factors, including BMI of patients, LCA ligation, and the distance from the lower edge of the tumors to the anus are related with anastomotic leakage. The individual treatments should be considered based on the patient's clinical condition. CT was recommended 7 days postoperatively when anastomotic leakage was highly suspected.

[The linear dimensions of human body measurements of Chinese male pilots in standing posture].

OBJECTIVE: To provide the latest anthropometric data of Chinese male pilots on a large scale. METHOD: 94 linear dimensions of human body measurements were defined, of which there are 42 fundamental items and 52 recommended items. The computer databanks were programmed, in which the subprograms were preset for data checking such as extreme value examination, logical judgement for data relationship, and measuring-remeasuring difference test. All workers were well trained before pilot measurements. 1739 male pilots from China Air Force was measured for the 42 fundamental items, and of which 904 pilots were measured for the 52 recommended items. RESULT: Mean, standard deviation, the maximum value, the minimal value, and the 5th, 50th, 95th percentile data of all the 94 items were given. The quality of the data was stable and reliable. CONCLUSION: All data of the 94 linear dimensions of human body measurements were valid and reliable with high precision.