Giant dilatation of pancreatic duct associated with congenital anomaly of the pancreatic ductal system and small neuroendocrine tumor.

Dilatation of the main pancreatic duct (MPD) ˃50 mm is a rare phenomenon. We present the case of successful surgical treatment a 63-year-old female patient who presented epigastric pain and weight loss of 10 kg in 6 months. Based on preoperative examination, the dilatation of MPD was 75 mm. The preliminary diagnosis was main duct intraductal papillary mucinous neoplasm. Extended pylorus-preserving pancreatoduodenectomy with resection of the body of the pancreas was performed. According to the results of pathological and immunohistochemical studies, performed by independent experts, the final diagnosis of congenital anomaly of the ductal system and neuroendocrine tumor of the accessory pancreatic duct was made.

Massive Localized Abdominal Lymphedema: A Case Report with Literature Review.

Massive localized lymphedema (MLL) is a rare disease caused by the obstruction of lymphatic vessels with specific clinical morphological and radiological characteristics. People with morbid obesity are mainly affected by MLL. Lymphedema is easily confused with soft tissue sarcoma and requires differential diagnosis, both the possibility of an MLL and also carcinoma manifestations in the soft tissues. The possible causes of massive lymphedema include trauma, surgery, and hypothyroidism. This report is the first case of MLL treated surgically in the Russian Federation. Detailed computed tomography (CT) characteristics and an electron microscope picture of MLL are discussed. A 50-year-old woman (body mass index of 43 kg/m 2 ) with MLL arising from the anterior abdominal wall was admitted to the hospital for surgical treatment. Its mass was 22.16 kg. A morphological study of the resected mass confirmed the diagnosis of MLL. We review etiology, clinical presentation, diagnosis, and treatment of MLL. We also performed an electron-microscopic study that revealed interstitial Cajal-like cells telocytes not previously described in MLL cases. We did not find similar findings in the literature. It is possible that the conduction of an ultrastructural examination of MLL tissue samples will further contribute to the understanding of MLL pathogenesis.

Radiomics model-based algorithm for preoperative prediction of pancreatic ductal adenocarcinoma grade.

OBJECTIVE: To develop diagnostic radiomic model-based algorithm for pancreatic ductal adenocarcinoma (PDAC) grade prediction. METHODS: Ninety-one patients with histologically confirmed PDAC and preoperative CT were divided into subgroups based on tumor grade. Two histology-blinded radiologists independently segmented lesions for quantitative texture analysis in all contrast enhancement phases. The ratio of densities of PDAC and unchanged pancreatic tissue, and relative tumor enhancement (RTE) in arterial, portal venous, and delayed phases of the examination were calculated. Principal component analysis was used for multivariate predictor analysis. The selection of predictors in the binary logistic model was carried out in 2 stages: (1) using one-factor logistic models (selection criterion was p < 0.1); (2) using regularization (LASSO regression after standardization of variables). Predictors were included in proportional odds models without interactions. RESULTS: There were significant differences in 4, 16, and 8 texture features out of 62 for the arterial, portal venous, and delayed phases of the study, respectively (p < 0.1). After selection, the final diagnostic model included such radiomics features as DISCRETIZED HU standard, DISCRETIZED HUQ3, GLCM Correlation, GLZLM LZLGE for the portal venous phase of the contrast enhancement, and CONVENTIONAL_HUQ3 for the delayed phase of CT study. On its basis, a diagnostic model was built, showing AUC for grade ≥ 2 of 0.75 and AUC for grade 3 of 0.66. CONCLUSION: Radiomics features vary in PDAC of different grades and increase the accuracy of CT in preoperative diagnosis. We have developed a diagnostic model, including texture features, which can be used to predict the grade of PDAC. KEY POINTS: • A diagnostic algorithm based on CT texture features for preoperative PDAC grade prediction was developed. • The assumption that the scanning protocol can influence the results of texture analysis was confirmed and assessed. • Our results show that tumor differentiation grade can be assessed with sufficient diagnostic accuracy using CT texture analysis presented in this study.

Computed tomography-based radiomics approach in pancreatic tumors characterization.

Radiomics (or texture analysis) is a new imaging analysis technique that allows calculating the distribution of texture features of pixel and voxel values depend on the type of ROI (3D or 2D), their relationships in the image. Depending on the software, up to several thousand texture elements can be obtained. Radiomics opens up wide opportunities for differential diagnosis and prognosis of pancreatic neoplasias. The aim of this review was to highlight the main diagnostic advantages of texture analysis in different pancreatic tumors. The review describes the diagnostic performance of radiomics in different pancreatic tumor types, application methods, and problems. Texture analysis in PDAC is able to predict tumor grade and associates with lymphovascular invasion and postoperative margin status. In pancreatic neuroendocrine tumors, texture features strongly correlate with differentiation grade and allows distinguishing it from the intrapancreatic accessory spleen. In pancreatic cystic lesions, radiomics is able to accurately differentiate MCN from SCN and distinguish clinically insignificant lesions from IPMNs with advanced neoplasia. In conclusion, the use of the CT radiomics approach provides a higher diagnostic performance of CT imaging in pancreatic tumors differentiation and prognosis. Future studies should be carried out to improve accuracy and facilitate radiomics workflow in pancreatic imaging.

Extracorporeal Partial Nephrectomy with Orthotopic Autotransplantation under Pharmaco-Cold Ischaemia for Cancer of a Single Kidney: A Case Report.

Up to 10% of patients with renal cell carcinoma (RCC) have locally advanced disease with venous tumour thrombosis involving the inferior vena cava (IVC). 30-50% of them present with synchronous metastatic disease. Surgical treatment remains the only potentially radical method for patients suffering from RCC and IVC tumour thrombosis without distant metastases. Five-year cancer-specific survival for such patients is 40-60%. The role of surgery in the treatment of RCC is significant, even if only cytoreductive operation is possible. Nephron-sparing surgery (NSS) is reasonably preferable for patients suffering from single kidney RCC, but it is not always radical enough. Extracorporeal approach allows to perform a radical dissection of the tumour in special complicated cases, but it is seldom used because of technical difficulties. We present a case of successful NSS by extracorporeal approach in our modification for RCC with IVC tumour thrombosis.

Leiomyosarcoma of the inferior vena cava.

Leiomyosarcoma of the inferior vena cava (IVC) is a rare malignancy. Approximately 350 cases of this disease are known worldwide. Surgical treatment of this condition remains an extremely difficult task. In this case report, we present an experience of successful radical treatment of a leiomyosarcoma of the suprarenal IVC without vascular reconstruction. The patient was treated with resection of the suprarenal portion of the IVC with the tumor; however, in view of adequate blood outflow from the right lobe of the liver, prosthetic replacement of the IVC with right hepatic vein reimplantation was not performed.

Giant hepatic angiomyolipoma: a case report.

Hepatic angiomyolipoma (AML) is a rare mesenchymal tumour with an undetermined malignant potential. Clinical symptoms are non-specific. The radiological hallmarks are high vascularization of lesion and presence of macroscopic fat. The proportion of fatty tissue varies significantly and discrepancies between pre-operative imaging and histological findings are observed in more than 50% of cases. Visualization of the draining vein may aid in differentiation between AML and hepatocellular carcinoma with abundant fatty component. Biopsy is indicated in ambiguous cases. Presence of clinical symptoms warrants surgical treatment. We present a clinical case of giant hepatic AML, discuss its typical features and treatment options.

Nonhypervascular pancreatic neuroendocrine tumors: Spectrum of MDCT imaging findings and differentiation from pancreatic ductal adenocarcinoma.

PURPOSE: The purpose of our study was to determine contrast-enhanced MDCT features to differentiate nonhypervascular pancreatic neuroendocrine tumors (PNETs) from pancreatic ductal adenocarcinomas (PDACs). METHODS: and materials: We included 74 patients with PNETs and 80 patients with PDACs who underwent preoperative MDCT. Two radiologists evaluated the morphologic characteristic and enhancement patterns of the tumors. Quantitative and qualitative analysis was performed, including evaluation of tumor size, homogeneity, contrast enhancement pattern, presence of pancreatic duct dilatation and tumor invasion to the adjacent vessels and peripancreatic infiltration. Tumor-to-pancreas enhancement ratio was defined as the Hounsfield units (HU) value of the tumor divided by the HU value of the pancreas. the first group was hypervascular PNETs showing hyperenhancement on arterial phase images and nonhypervascular PNETs, showing iso- or hypoenhancement on arterial phase images. After that, two radiologists estimated the possibilities of PNET or PDAC were for nonhypervascular PNETs. RESULTS: On the basis of arterial enhancement, 43 PNETs were hypervascular and 31 were nonhypervascular. When compared to PDAC, nonhypervascular PNETs more frequently had well-defined tumor margins, intratumoral cystic components, calcifications and blood vessels and less frequently had main pancreatic duct dilatation, peripancreatic infiltration and vascular invasion (p < 0.01 for all). Nonhypervascular PNETs had higher tumor-to-pancreas enhancement ratio in venous phase (1.02 vs. 0.78, p = 0.012). Nonhypervascular PNETs more often had portal-venous hyperenhancement or persistent isoenhancement, while PDAC more often had persistent hypoenhancement or gradual delayed enhancement (p < 0.001). The absence of pancreatic duct dilatation and portal-venous hyperenhancement or persistent isoenhancement were the independent predictors for nonhypervascular PNETs. (The most accurate MDCT-findings to predict nonhypervascular PNET were the absence of pancreatic duct dilatation and peripancreatic infiltration (79% and 92% accuracy), portal-venous phase hyperenhancement or persistent isoenhancement (77%), the presence of intratumoral blood vessels (77%) and relative enhancement intensity in venous phase >0.9 (76%). Using these criteria, the area under curve for differentiation of PNET from PDAC was 0.906-0.846. CONCLUSION: Combined assessment of the enhancement and morphologic characteristics can improve the differentiation between nonhypervascular PNETs and PDAC at contrast-enhanced MDCT.

Successful surgical treatment with ex vivo technique in a patient with renal artery aneurysm rupture and bilateral arteriovenous fistula.

Renal arteriovenous fistulas are pathologic communications between the renal arteries and veins without interconnecting capillaries. Reports on the combination of fibromuscular dysplasia, aneurysms, and renal arteriovenous fistula are extremely rare in the literature. In the case of renal arteriovenous aneurysm rupture, urgent nephrectomy was the only life-saving procedure reported. The ex vivo approach seems to be an appropriate alternative to nephrectomy. This article presents a case of successful treatment of bilateral fibromuscular dysplasia with aneurysm and arteriovenous fistulas complicated by renal artery aneurysm rupture.

Value of two-phase dynamic multidetector computed tomography in differential diagnosis of post-inflammatory strictures from esophageal cancer.

AIM: To characterize the computed tomography (CT) findings in patients with post-inflammatory esophageal strictures (corrosive and peptic) and reveal the optimal scanning phase protocols for distinguishing post-inflammatory esophageal stricture and esophageal cancer. METHODS: Sixty-five patients with esophageal strictures of different etiology were included in this study: 24 patients with 27 histopathologically confirmed corrosive strictures, 10 patients with 12 peptic strictures and 31 patients with esophageal cancer were evaluated with a two-phase dynamic contrast-enhanced MDCT. Arterial and venous phases at 10 and 35 s after the attenuation of 200 HU were obtained at the descending aorta, with a delayed phase at 6-8 min after the start of injection of contrast media. For qualitative analysis, CT scans of benign strictures were reviewed for the presence/absence of the following features: "target sign", luminal mass, homogeneity of contrast medium uptake, concentric wall thickening, conically shaped suprastenotic dilatation, smooth boundaries of stenosis and smooth mucous membrane at the transition to stenosis, which were compared with a control group of 31 patients who had esophageal cancer. The quantitative analysis included densitometric parameter acquisition using regions-of-interest measurement of the zone of stenosis and normal esophageal wall and the difference between those measurements (ΔCT) at all phases of bolus contrast enhancement. Esophageal wall thickening, length of esophageal wall thickening and size of the regional lymph nodes were also evaluated. RESULTS: The presence of a concentric esophageal wall, conically shaped suprastenotic dilatation, smooth upper and lower boundaries, "target sign" and smooth mucous membrane at the transition to stenosis were suggestive of a benign cause, with sensitivities of 92.31%, 87.17%, 94.87%, 76.92% and 82.05%, respectively, and specificities of 70.96%, 89.66%, 80.65%, 96.77% and 93.55%, respectively. The features that were most suggestive of a malignant cause were eccentric esophageal wall thickening, tuberous upper and lower boundaries of stenosis, absence of mucous membrane visualization, rupture of the mucous membrane at the upper boundary of stenosis, cup-shaped suprastenotic dilatation, luminal mass and enlarged regional lymph nodes with specificities of 92.31% 94.87%, 67.86%, 100%, 97.44%, 94.87% and 82.86%, respectively and sensitivities of 70.97%, 80.65%, 96.77%, 80.65%, 54.84%, 87.10% and 60%, respectively. The highest tumor attenuation occurred in the arterial phase (mean attenuation 74.13 ± 17.42 HU), and the mean attenuation difference between the tumor and the normal esophageal wall (mean ΔCT) in the arterial phase was 23.86 ± 19.31 HU. Here, 11.5 HU of ΔCT in the arterial phase was the cut-off value used to differentiate esophageal cancer from post-inflammatory stricture (P = 0.000). The highest attenuation of post-inflammatory strictures occurred in the delayed phase (mean attenuation 71.66 ± 14.28 HU), and the mean ΔCT in delayed phase was 34.03 ± 15.94 HU. Here, 18.5 HU of ΔCT in delayed phase was the cut-off value used to differentiate post-inflammatory stricture from esophageal cancer (P < 0.0001). CONCLUSION: The described imaging findings reveal high diagnostic significance in the differentiation of benign strictures from esophageal cancer.

Low radiation dose 256-MDCT angiography of the carotid arteries: effect of hybrid iterative reconstruction technique on noise, artifacts, and image quality.

UNLABELLED: To evaluate the effect of hybrid iterative reconstruction on qualitative and quantitative parameters at low dose carotid CTA. MATERIALS AND METHODS: 44 consecutive patients were enrolled in the study. First group (n=22) was examined under 120 kV 250 mAs, second group (n = 22) - 100 kV 250 mAs. CT images in first group were reconstructed only with the filtered back projection (FBP). CT data in second group were reconstructed both with FBP and three levels of hybrid iterative reconstruction algorithm (iDose). We compared quantitative and qualitative parameters among the two groups and among four different reconstructions in second group. RESULTS: Effective dose in 120 kV and 100 kV group was 7.18 ± 1.19 mSv and 4.14 ± 1.03 mSv, respectively (p<0.0001). Mean arterial attenuation was about 25% higher in second group (236.5 ± 46 HU vs. 302.6 ± 32.7 HU; p<0.0001). Image noise at the level of humeral belt was 32.5 ± 12.5 in 100 kV group and 26.3 ± 13.3 in 120 kV (p = 0.115). Average noise decreased when using 3 levels of iDose up to 23.6 ± 6.4, 17.7 ± 5.6 and 13.7 ± 5.1, respectively (p = 0.00001). Mean CNR increased to 10.38 ± 3.87, 14.5 ± 5.21 and 18.32 ± 8.61, respectively (p<0.05). The presence of artifacts on the level of humeral belt in 120 kV group was 14%, in 100 kV - 41% (p = 0.002). The difference in visual scores between standard and low-dose protocol was significant (p = 0.008). When applying iterative reconstruction the frequency of streak artifacts decreased dramatically (p<0.0001). Most studies had excellent quality with no artifacts while using highest level of iDose. CONCLUSION: According to the results of our study low dose CT angiography using hybrid iterative reconstruction may provide sufficient image quality and allows for significant reduction of patient dose.

Virtual modeling of robot-assisted manipulations in abdominal surgery.

AIM: To determine the effectiveness of using multidetector computed tomography (MDCT) data in preoperative planning of robot-assisted surgery. METHODS: Fourteen patients indicated for surgery underwent MDCT using 64 and 256-slice MDCT. Before the examination, a specially constructed navigation net was placed on the patient's anterior abdominal wall. Processing of MDCT data was performed on a Brilliance Workspace 4 (Philips). Virtual vectors that imitate robotic and assistant ports were placed on the anterior abdominal wall of the 3D model of the patient, considering the individual anatomy of the patient and the technical capabilities of robotic arms. Sites for location of the ports were directed by projection on the roentgen-positive tags of the navigation net. RESULTS: There were no complications observed during surgery or in the post-operative period. We were able to reduce robotic arm interference during surgery. The surgical area was optimal for robotic and assistant manipulators without any need for reinstallation of the trocars. CONCLUSION: This method allows modeling of the main steps in robot-assisted intervention, optimizing operation of the manipulator and lowering the risk of injuries to internal organs.

Pancreatic adenocarcinoma: Outstanding problems.

Pancreatic adenocarcinoma remains the fourth leading cause of cancer-related death and is one of the most aggressive malignant tumors with an overall 5-year survival rate of less than 4%. Surgical resection remains the only potentially curative treatment but is only possible for 15%-20% of patients with pancreatic adenocarcinoma. About 40% of patients have locally advanced nonresectable disease. In the past, determination of pancreatic cancer resectability was made at surgical exploration. The development of modern imaging techniques has allowed preoperative staging of patients. Institutions disagree about the criteria used to classify patients. Vascular invasion in pancreatic cancers plays a very important role in determining treatment and prognosis. There is no evidence-based consensus on the optimal preoperative imaging assessment of patients with suspected pancreatic cancer and a unified definition of borderline resectable pancreatic cancer is also lacking. Thus, there is much room for improvement in all aspects of treatment for pancreatic cancer. Multi-detector computed tomography has been widely accepted as the imaging technique of choice for diagnosing and staging pancreatic cancer. With improved surgical techniques and advanced perioperative management, vascular resection and reconstruction are performed more frequently; patients thought once to be unresectable are undergoing radical surgery. However, when attempting heroic surgery, a realistic approach concerning the patient's age and health status, probability of recovery after surgery, perioperative morbidity and mortality and life quality after tumor resection is necessary.