Contrast-enhanced Abdominal CT Research Articles

A case of spontaneous mesenteric hematoma with diagnostic difficulty

BackgroundSpontaneous mesenteric hematoma (SMH) is a rare condition characterized by intraperitoneal hemorrhage of unknown etiology. SMH without worsening of general status allows conservative management; however, patients showing chronological changes on imaging require surgical intervention to rule out possible malignancy.Case presentationA 69-year-old man was referred to our hospital to evaluate an abdominal mass with no associated clinical symptoms. He had a history of chronic hepatitis C and diabetes mellitus. Six months earlier, computed tomography (CT) revealed a 75-mm tumor arising from the jejunum, suspected to be a gastrointestinal stromal tumor (GIST) of the small intestine. Following a further 6 months of observation, the patient was referred to our hospital. Abdominal contrast-enhanced CT revealed a well-defined heterogeneous round tumor with a maximum diameter of 75 mm adjacent to the upper jejunum. The tumor was accompanied by calcification at the periphery, with no evidence of augmentation over the prior 6 months. Diffuse lymphadenopathy was observed around the aorta and splenic artery. Under the diagnosis of GIST arising from small intestine, the patient underwent elective surgery. The resection revealed an elastic soft tumor at the mesentery adjacent to the upper jejunum with severe adhesion between the tumor and jejunum. The tumor origin was unclear; thus, we performed mesenteric excision and partial enterectomy without lymph node dissection.The tumor was surrounded by fibrous capsular tissue containing massive hemosiderin deposits and cholesterol crystals showing partial calcification, resulting in a diagnosis of spontaneous hematoma of the mesentery.ConclusionsWe report a case of SMH mimicking small intestinal GIST. It is difficult to diagnose long-established SMH because its radiological features change with time, and more case reports are needed to improve the accuracy of diagnosis.

The Value of Low-dose Prospective Dual-energy Computed Tomography with Iodine Mapping in the Diagnosis of Gastric Cancer.

This study investigated the radiation dose and value of prospective dualenergy computed tomography (DECT) in the diagnosis of gastric cancer. Sixty patients scheduled for computed tomography (CT) for preoperative staging were divided into two groups. Thirty patients (Group A) underwent a single contrast-enhanced abdominal CT acquisition using a dual-source mode (100 kV/140 kV). Weighted average images of the two-kilovolt acquisitions and iodine maps were created. The remaining 30 patients underwent a standard CT scan (Group B). Two observers performed a blinded read of the images for gastric lesions, evaluating the image quality and recording effective dose. During the blinded read, observers found 90% (27/30) of the cancers in both groups. The mean imaging quality scores were 2.1±0.9 for Group A, and 2.3±1.1 for Group B. The effective mean doses were 6.59±0.59 mSv and 25.86±0.44 mSv for Groups A and B, respectively. Compared with the control group (B), the imaging quality in the low-dose group decreased a little, but the radiation dose substantially decreased by 74.6%. The new DECT technique is valuable for examining gastric cancer patients. The dualkV scan mode can substantially reduce radiation dose while preserving good diagnostic image quality.

Performance evaluation of two iterative reconstruction algorithms, MBIR and ASIR, in low radiation dose and low contrast dose abdominal CT in children.

The adverse effect of low-dose CT on image quality may be mitigated using iterative reconstructions. The purpose of this study was to evaluate the performance of the full model-based iterative reconstruction (MBIR) and adaptive statistical reconstruction (ASIR) algorithms in low radiation dose and low contrast dose abdominal contrast-enhanced CT (CECT) in children. A total of 59 children (32 males and 27 females) undergoing low radiation dose (100kVp) and low contrast dose (270 mgI/ml) abdominal CECT were enrolled. The median age was 4.0years (ranging from 0.3 to 13years). The raw data were reconstructed with MBIR, ASIR and filtered back-projection (FBP) algorithms into 6 groups (MBIR, 100%ASIR, 80%ASIR, 60%ASIR, 40%ASIR and FBP). The CT numbers, standard deviations, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of liver, pancreas, kidney and abdominal aorta were measured. Two radiologists independently evaluated the subjective image quality including the overall image noise and structure display ability on a 4-point scale with 3 being clinically acceptable. The measurements among the reconstruction groups were compared using one-way ANOVA. The overall image noise score and display ability were 4.00 ± 0.00 and 4.00 ± 0.00 with MBIR and 3.27 ± 0.33 and 3.25 ± 0.43 with ASIR100%, respectively, which met the diagnostic requirement; other reconstructions couldn't meet the diagnostic requirements. Compared with FBP images, the noise of MBIR images was reduced by 62.86-65.73% for the respective organs (F = 48.15-80.47, P < 0.05), and CNR increased by 151.38-170.69% (F = 22.94-38.02, P < 0.05). MBIR or ASIR100% improves the image quality of low radiation dose and contrast dose abdominal CT in children to meet the diagnostic requirements, and MBIR has the best performance.

Branch-like gas in a commercial diver’s liver: a case report

We report the case of a 42-year-old commercial diver who presented with palpitations, arthralgia, tachypnea and vomiting after three hours of repetitive dives to 25-30 meters below sea level (msw). He was diagnosed with severe decompression sickness (Type II DCS) based on his dive history, his abrupt ascent to the surface within minutes, and systemic symptoms with mild hypovolemic shock. Besides remarkable cutis marmorata on the torso, the patient was also found positive for diffuse branch-like pneumatosis in the liver, mesentery and intestines on an abdominal computed tomography (CT). His vitals were relatively stable, with a soft distended abdomen and mild tenderness over the right upper quadrant. He was treated with hyperbaric oxygen (HBO2) treatment in addition to essential crystalloid resuscitation. The abdominal pneumatosis resolved completely after two HBO2 sessions. Post-diving intra-abdominal pneumatosis is a rare complication of DCS. In our case it was difficult for dive doctors to diagnose promptly because an emergency abdominal CT was not a routine for potential DCS cases. We propose that a contrast-enhanced abdominal CT, which usually involves a intravenous injection of imaging agent, should be considered in emergency management of these patients, especially when they present with gastrointestinal symptoms.

Evaluation of inferior mesenteric vessel and ureter by contrast-enhanced abdominal pelvic CT and its clinical influence on laparoscopic rectal surgery

Objective: To assess the anatomic relationship of inferior mesenteric artery (IMA)/inferior mesenteric vein (IMV) with ureter by contrast-enhanced abdominal pelvic CT, in order to provide guidance for vascular management and ureteral protection in laparoscopic rectal surgery. Methods: A retrospective cohort study was conducted. Image data of contrast-enhanced abdominal pelvic CT at Department of Medical Radiography of Peking University First Hospital in November 2018 were enrolled. Exclusion criteria: (1) previous history of abdominal or pelvic surgery; (2) scoliosis deformities; (3) missing images; (4) minors; (5) inferior mesenteric vascular disease or tumor involvement resulting in suboptimal imaging; (6) poor image quality. Finally, contrast-enhanced abdominal pelvic CT data of 249 cases were collected, including 120 males and 129 females with mean age of (60.1±13.4) years. Multi-planar reconstruction (MPR) and maximum intensity projection (MIP) were used to evaluate the anatomic relationship of IMA/IMV with ureter. IMA root location, IMA length, branch types of IMA, distance between major branches, distance between IMA/IMV and ureter at the level of root of IMA, left colic artery (LCA) root, abdominal aortic bifurcation, and sacral promontory were measured and association between IMA/IMV and ureter site was summarized. Results: The distance from IMA root to the aortic bifurcation and sacral promontory was (42.0±8.5) mm and (101.8±14.0) mm, respectively. The length of IMA was (38.5±10.7) mm. The proportion of IMA roots locating at levels of the 2nd, 3rd, and 4th lumbar vertebra was 3.2% (8/249), 79.5% (198/249), and 17.3% (43/249), respectively. The higher the level of the lumbar vertebra, the longer the IMA [length of IMA originating from the 2nd, 3rd, 4th lumbar vertebra level: (42.4±10.9) mm, (39.5±10.4) mm, (33.0±10.9) mm, respectively; F=7.48, P<0.001]. In 111 cases (44.6%), LCA arose independently from IMA (type 1), and the distance between LCA and the first branch of sigmoid artery (SA) was (15.0±7.4) mm; in 56 cases (22.5%), LCA and SA had a common trunk (type 2), with a length of (11.0±8.5) mm; in 78 cases (31.3%), LCA branched with SA at the same point (type 3); LCA was absent in 4 cases (1.6%)(type 4). The length of IMA in LCA-deficient type 4 was (54.8±18.0) mm, which was longer than (38.2±10.5) mm in LCA-presence type (type 1, type 2 and type 3) and the difference was statistically significant (t=-3.11, P=0.002). The distance between the ureter and IMA was the longest at the level of IMA root [(35.7±8.1) mm], was the shortest at the level of the aortic bifurcation [(22.4±6.4) mm], and the distance between the ureter and IMA in different planes was significantly different (F=185.70, P<0.001). The distance between the ureter and IMV was the longest at the level of the sacral promontory [(21.1±9.0) mm], was the shortest at the level of LCA root [(12.0±5.7) mm], whose difference was also statistically significant (F=87.66, P<0.001). Conclusions: CT post-processing techniques including MPR and MIP can efficiently and accurately assess the branch types of IMA and anatomical relationship between IMA/IMV and ureter, and provide insights into laparoscopic rectal surgery for surgeons. IMA/IMV and ureter depart farthest at the level of IMA root. Artery first and plane second strategy in the middle approach of laparoscopic rectal surgery is considerable and feasible.

Assessment of ureteric diameter using contrast-enhanced helical abdominal computed tomography

BackgroundAssessment of ureteric size is imperative for diagnosis of urinary tract abnormalities especially with regard to obstructive pathologies. The ureteric opacification and distension obtained from contrast-enhanced computed tomography allows for differentiation from surrounding soft tissue and better assessment of ureteric diameter. Abdominal computed tomographic scans are commonly requested for the evaluation of the urinary tract, and we therefore aim to establish a normal reference value of the ureteral diameter using contrast-enhanced computed tomographic scans of the abdomen.Method With the purpose of establishing our local normogram of ureteric diameter, we did a retrospective study of archived images of 170 patients referred to the radiology department of a tertiary hospital for contrast-enhanced abdominal CT from January 2016 to June 2018. The largest transverse dimension along the course of the ureter beginning 1–2 cm below the ureteropelvic junction was measured at the delayed phase and obtained data subjected to analysis using SAS software version 9.3 with statistical level of significance set at 0.05.ResultA total number of 340 ureters in 170 patients were analyzed with the mean age of 47.9 years (range 1.0–94.0 years) and male-to-female ratio of 1.2:1. The mean left ureteric diameter of all patients was 4.3 mm (range 1.7–8.0 mm) while the mean right ureteric diameter of all patients was 4.4 mm (range 1.5–8.0 mm). Ninety-five percent of ureters in our study measured 6.9 mm and less with no significant difference in ureteric sizes across gender and ages.ConclusionThe mean CT normogram for ureteric caliber is 4.3–4.4 mm with no significant age and gender difference and 7 mm proposed as upper limit of normal.

Radiomic mapping model for prediction of Ki-67 expression in adrenocortical carcinoma

To determine the value of contrast-enhanced computed tomography (CT)-derived radiomic features in the preoperative prediction of Ki-67 expression in adrenocortical carcinoma (ACC) and to detect significant associations between radiomic features and Ki-67 expression in ACC. For this retrospective analysis, patients with histopathologically proven ACC were reviewed. Radiomic features were extracted for all patients from the preoperative contrast-enhanced abdominal CT images. Statistical analysis identified the radiomic features predicting the Ki-67 index in ACC and analysed the correlation with the Ki-67 index. Fifty-three cases of ACC that met eligibility criteria were identified and analysed. Of the radiomic features analysed, 10 showed statistically significant differences between the high and low Ki-67 expression subgroups. Multivariate linear regression analysis yielded a predictive model showing a significant association between radiomic signature and Ki-67 expression status in ACC (R2=0.67, adjusted R2=0.462, p=0.002). Further analysis of the independent predictors showed statistically significant correlation between Ki-67 expression and shape flatness, elongation, and grey-level long run emphasis (p=0.002, 0.01, and 0.04, respectively). The area under the curve for identification of high Ki-67 expression status was 0.78 for shape flatness and 0.7 for shape elongation. Radiomic features derived from preoperative contrast-enhanced CT images show encouraging results in the prediction of the Ki-67 index in patients with ACC. Morphological features, such as shape flatness and elongation, were superior to other radiomic features in the detection of high Ki-67 expression.

The aortic and hepatic contrast enhancement at CT and its correlations with various body size index

Objective To evaluate the effect of height (HT), total body weight (TBW), body mass index (BMI), lean body weight (LBW), body surface area (BSA) and blood volume (BV) on aortic and liver contrast enhancement during upper abdominal contrast-enhanced CT scans. Methods One hundred and thirteen enrolled patients underwent upper abdominal multiphase contrast-enhanced CT scans. The enhancement (ΔHU) of aorta in hepatic arterial phase and liver parenchyma in portal venous phase were measured and calculated. The ΔHU values difference of aorta and liver parenchyma in subgroups between males and females, TBW<60 kg and TBW≥60 kg, BMI<25 kg/m2 and BMI≥25 kg/m2 were compared. To evaluate the effect of the patient′s body parameters on aortic and hepatic enhancement, we performed simple linear regression analyses between the change in CT numbers per gram of iodine (ΔHU/gI) at aorta and liver and each of the following: HT, TBW, BMI, LBW, BSA, and BV. Pearson and t test were used. Results The mean ΔHU values of aorta and liver were significantly lower at males than that of at females (P<0.05). They were higher at TBW<60 kg patients than at TBW≥60 kg patients(P<0.05), and the mean ΔHU values of the liver at BMI<25 kg/m2 patients were significantly higher than at BMI≥25 kg/m2 patients(P<0.05). The proportion of the ΔHU values at liver less than 50 HU was higher at males (18.3%, 11/60) than at females (7.5%, 4/53). The most obvious negative correlation coefficients were found between the ΔHU/gI of aorta and LBW at hepatic arterial phase (r=-0.559, P<0.01), and between the ΔHU/gI of liver and BSA at portal venous phase (r=-0.680, P<0.01). Conclusion LBW or BSA could be the alternative body index to TBW for the calculation of personalized iodine dose protocol at aortic and liver enhanced CT scans. Key words: Contrast media; Tomography, X-ray computed; Aorta; Liver

Renal Parenchymal Volumetric Expansion Assessed by CT Imaging After Laparoscopic Cyst Decortication.

To delineate the expansion of the renal parenchyma using volumetric CT imaging before and after the laparoscopic cyst decortication procedure and to determine the possible associations between parenchymal expansion and laboratory parameters and cyst volume. Thirty-five patients that underwent laparoscopic cyst decortication were included in this prospective study. Abdominal contrast-enhanced CT was performed in all patients in the preoperative and postoperative period. Semi-automatic volume quantification was undertaken offline, and renal parenchymal volumes before and after cyst decortication, as well as serum creatinine and estimated glomerular filtration rate (eGFR) were compared. The changes in serum creatinine and eGFR in the postoperative period were non-significant. The mean postoperative renal parenchymal volumes were higher compared to the preoperative measurements for both observations (P = .014 and .034 for the first and second measurements, respectively). There was no correlation between the volumetric change and the cyst volume (r = -0.18, P = .560). In patients undergoing laparoscopic cyst decortication, post-operative parenchymal expansion can be detected using volumetric CT imaging to confirm the immediate benefits of the procedure.

The orthogonal measurements approach in estimating spleen size on CT images.

To find out which single measurement and/or linear regression model correlates well with splenic volume using the orthogonal measurements approach. The study relied on retrospective analysis of 205 contrast-enhanced abdominal CT examinations carried out in adult patients using a 320-detector CT system. CT volumetry was conducted by a semi-automated, model and threshold based segmentation algorithm that enables voxel-based volume calculation of abdominal organs. The orthogonal measurements were carried out in axial sections by measuring the maximum diameters of spleen projected in sagittal, coronal and transverse planes. In addition, we calculated the diagonal diameter of spleen, which is a derivative of orthogonal measurements. Statistical analysis included calculation of interobserver agreement on orthogonal measurements, followed by model building using linear regression analysis of the measurements. The interobserver agreement between two radiologists was very strong for all orthogonal measurements (r ≥ 0.971). The highest model performance was detected with the diagonal diameter (r2 = 0.956), followed by the superoinferior diameter (r2 = 0.857). Agreement statistics revealed that the regression formula derived from the diagonal diameter outperformed that of superoinferior diameter. The diagonal diameter appears to be the best parameter which correlates with splenic volume, whereas the superoinferior diameter can be an alternative in daily CT reporting practice. The orthogonal measurements approach not only provides a high interobserver agreement, but also the diagonal diameter can be translated into ultrasound studies.

Diagnostic efficacy of routine contrast-enhanced abdominal CT for the assessment of osteoporosis in the Turkish population

Background/aim This study aimed to evaluate the diagnostic efficacy of vertebral Hounsfield unit (HU) values on routine contrast-enhanced abdominal computed tomography (CT) scans for the assessment of osteoporosis using dual-energy X-ray absorptiometry (DXA) T-scores as a reference standard.Materials and methods A total of 111 consecutive patients who underwent contrast-enhanced abdominal CT examination for any indication and DXA within a 6-month period were retrospectively analyzed. The CT attenuation values of trabecular bone in HUs were measured in axial and sagittal planes from lumbar vertebrae 1–4 (L1–L4). The correlation between the DXA T-scores and HU values measured on the CT scans was evaluated by Pearson’s correlation test. Areas under the curves (AUCs) were calculated by receiver operating characteristic analysis for diagnostic proficiency, and threshold values were determined. Paired t-test and Bland–Altman plot test were used to evaluate the correlation between axial and sagittal HU values.Results There was a strong correlation between the DXA T-scores and HU values of all the lumbar vertebrae (P < 0.001). The highest correlation was for the L3 vertebra; L3 was thus chosen for additional analyses. The mean axial and sagittal L3 attenuations were 133.7 HU and 131.9 HU, respectively. The axial measurements were not significantly different from the sagittal measurements, with a mean difference of 1.8 HU (P > 0.05). The L3 axial CT attenuation threshold for 90% sensitivity was 170 HU and that for 90% specificity was 102 HU for distinguishing osteoporosis from osteopenia and normal bone mineral density (BMD). To distinguish the low BMD group from the normal group, the L3 axial CT attenuation threshold for approximately 90% sensitivity was 102 HU and for 90% specificity was 165 HU.Conclusion The HUs derived from routine contrast-enhanced abdominal CT scans can be used for the evaluation of osteoporosis, without additional radiation exposure and cost.

Unusual ovarian vein thrombosis: A case report and review of the literature

Introduction: Ovarian vein thrombosis (OVT) is an uncommon but potentially serious clinical disorder, which mostly present in the postpartum period but can also occur with malignant and inflammatory conditions in the non-obstetrical patient. The diagnosis is mainly based on imaging techniques, in particular computed tomography (CT) and magnetic resonance, for their sensitivity and specificity. Case Report: We present a case of a 59-year-old female who was diagnosed with endometrial carcinoma. Her abdominal contrast-enhanced CT revealed an expanded right ovarian vein with soft tissue attenuation material in its lumen extending into the inferior vena cava, reaching the right atrium and ventricle. Conclusion: We describe this case of OVT, because, even though rare, it is a diagnosis to consider. Prompt recognition and treatment are crucial to avoid more severe outcomes.

Main pancreatic duct (MPD) diameter: contrast enhanced computed tomography (CECT) measurement in normal subjects in Sri Lanka

Introduction Dilatation of the MPD is associated with number of significant pancreatic pathologies. To identify the dilated MPD, it is of great importance to study the demographic data of the normal size of the MPD in a given population. Objective To assess the diameter of MPD in normal subjects. Methodology Prospective descriptive study was carried out at Colombo South Teaching Hospital from March 2016 to May 2016. All CECT abdomen and pelvis examinations performed during this period with clinical, biochemical and radiological evidence of normal pancreas were included. CT measurements of the MPD diameter were obtained by two individuals independently on the subjects who underwent abdominal CECT scans (16 section MDCT, 1-5mm increments, and dual phase) and each measurement was obtained in venous phase images for three times and mean value was taken. Results There were 190 men and 132 women with age ranging from 20–88 years (mean 53.6). MPD was adequately visualized only in 72% (n=231) of subjects. The mean diameter of the MPD in the head, body and tail were 2.9, 2.2 and 1.6 mm respectively. There is no statistical significant difference observed in MPD diameter between two sexes and the two age groups of 40 years (p>0.05). Conclusion The diameter values of MPD in our study are comparable to that of foreign population groups. However there was no correlation between MPD diameter with the age or sex in the study which was different to the published data which showed higher proportion of MPD diameter with increasing age and female gender.

Two cases of a perforated duodenal diverticulum after gastrectomy with Roux-en-Y reconstruction

BackgroundWhat type of reconstruction procedure should be applied is one of the important issues in surgery for gastric cancer. We have several options for reconstruction procedure after distal gastrectomy. The Billroth II and Roux-en-Y reconstruction have a duodenal stump while the Billroth I does not have it, which is the biggest structural difference in these procedures. An increase in intraduodenal pressure due to the formation of duodenum stump occasionally causes severe complication such as duodenal stump leakage; however, a duodenal diverticulum perforation after the Roux-en-Y reconstruction has not yet been reported. Herein, we report two cases of a perforated duodenal diverticulum after gastrectomy with the Roux-en-Y reconstruction.Case presentationThe first case was a 66-year-old man who presented to our hospital with an acute onset right-upper-quadrant abdominal pain. He had undergone laparoscopic distal gastrectomy with the Roux-en-Y reconstruction for the early gastric cancer 15 months before. A large periampullary diverticulum had been detected during the checkup before the gastrectomy. Abdominal contrast-enhanced CT showed a retroperitoneal fluid collection with gas present at the second part of the duodenum. Therefore, a perforated duodenal diverticulum with abdominal abscess was diagnosed, and an emergency laparotomy was performed. Pancreaticoduodenectomy was performed because of severe duodenal inflammation and surrounding tissue damage. The second case was a 52-year-old man who had undergone open distal gastrectomy for locally advanced gastric cancer. Multiple non-ampullary duodenal diverticula had also been identified during the preoperative checkup. On the 2nd postoperative day, he presented with a sudden-onset abdominal pain with peritoneal irritation signs, and intestinal fluid was identified through the intraperitoneal drainage tube placed in a suprapancreatic site during his previous gastrectomy. Therefore, an emergency laparotomy was performed. During laparotomy, a perforated diverticulum at the second part of the duodenum was detected. The perforated duodenum diverticulum was directly sutured with drainage of the retroperitoneal space.ConclusionsIt is necessary to recognize that the Roux-en-Y reconstruction after gastrectomy for gastric cancer patients with duodenal diverticulum might cause a perforation of the diverticulum.

Prediction of Histopathologic Growth Patterns of Colorectal Liver Metastases with a Noninvasive Imaging Method.

To predict histopathologic growth patterns (HGPs) in colorectal liver metastases (CRLMs) with a noninvasive radiomics model. Patients with chemotherapy-naive CRLMs who underwent abdominal contrast-enhanced multidetector CT (MDCT) followed by partial hepatectomy between January 2007 and January 2019 from two institutions were included in this retrospective study. Hematoxylin- and eosin-stained histopathologic sections of CRLMs were reviewed, with HGPs defined according to international consensus. Lesions were divided into training and validation datasets based on patients' sources. Radiomic features were extracted from pre- and post-contrast (arterial and portal venous) phase MDCT images, with review focusing on the segmented tumor-liver interface zones of CRLMs. Minimum redundancy maximum relevance and decision tree methods were used for radiomics modeling. Multivariable logistic regression analyses and ROC curves were used to assess the predictive performance of these models in predicting HGP types. A total of 126 CRLMs with histopathologic-demonstrated desmoplastic (n = 68) or replacement (n = 58) HGPs were assessed. The radiomics signature consisted of 20 features of each phase selected. The 3 phases fused radiomics signature demonstrated the best predictive performance in distinguishing between replacement and desmoplastic HGPs (AUCs of 0.926 and 0.939 in the training and external validation cohorts, respectively). The clinical-radiomics combined model showed good discrimination (C-indices of 0.941 and 0.833 in the training and external validation cohorts, respectively). A radiomics model derived from MDCT images may effectively predict the HGP of CRLMs, thus providing a basis for prognostic stratification and therapeutic decision-making.

Abdominal visceral adipose tissue is associated with unsuspected pulmonary embolism on routine CT scans in patients with gastrointestinal cancer.

Unsuspected pulmonary embolism (UPE) has been increasingly diagnosed as an incidental finding on CT scans for routine staging in cancer patients. Previous studies suggest that obesity is an independent risk factor for venous thromboembolism in patients with malignant tumors. In this study, we aimed to investigate the association between abdominal adipose tissue, especially visceral adipose tissue (VAT) and the occurrence of UPE in hospitalized patients with gastrointestinal cancer. Routine contrast-enhanced chest and abdominal CT scans of 1974 patients were retrospectively assessed for the presence of UPE, of which 58 patients were identified with UPE and 108 non-UPE patients were selected as the non-UPE control group based on several matching criteria. Abdominal adipose tissue was measured by volumes of VAT and subcutaneous adipose tissue (SAT) at the navel level. VAT, SAT, indwelling venous catheters, surgery, chemotherapy, and bed rest or immobilization were associated with the occurrence of UPE. Higher VAT volumes were associated with increased risk of UPE (odds ratio: 1.96; 95% confidence interval: 1.25, 3.06; p = 0.003) adjusting body mass index (BMI), bed rest or immobilization, surgery, chemotherapy and smoking, while SAT was not associated with UPE adjusting the same confounders (p = 0.117). No statistical association was found between BMI and UPE (p = 0.102). Higher VAT rather than SAT is associated with an increased risk of unsuspected pulmonary embolism on routine CT scans in hospitalized gastrointestinal cancer patients. Our findings indicate that VAT is a stronger risk factor for unsuspected pulmonary embolism than BMI and SAT in hospitalized patients with gastrointestinal cancer.

Pancreatic cancer: Assessment of neoadjuvant chemotherapy outcome based on radiomics of pretreatment computed tomography.

56 Background: To evaluate contrast enhanced-computed tomography (CE-CT) features to predicting treatment response and survival after neoadjuvant chemotherapy (NAC) for patients with borderline resectable and locally advanced pancreatic cancer. Methods: Sixty-one patients with pancreatic cancer receiving NAC were enrolled and underwent pre-treatment abdominal CE-CT. The patients were divided into groups according to post-treatment tumor size changes. Based on the pretreatment CE-CT images, 396 radiomic features were extracted from three-dimensional regions of interest. The optimal features were selected and three supervised machine learning classifiers were developed. Finally, univariate and multivariate analyses were performed to evaluate the ability of the selected features to predict the histopathological response and outcome. Results: Nine, seven, and five radiomic features, respectively, were selected as optimal features in three experiments. Two features, Haralick Entropy and Histogram Entropy, were consistent among the experiments and both were higher in patients with enlarged tumors. Moreover, a lower Histogram Entropy score was significantly associated with a better histopathological response (p = 0.008) and smaller tumor size (p = 0.041) in patients after tumor resection. In univariate Cox regression analysis, lower Histogram Entropy (p = 0.006) and lower Haralick Entropy (p = 0.001) predicted a better prognosis. Meanwhile, lower Haralick Entropy (p = 0.048) was an independent predictor of longer survival time in multivariate Cox regression analysis. Conclusions: Radiomic features are strongly correlated with NAC treatment response and prognosis in pancreatic cancer, suggesting the potential of imaging radiomics to help tailor the treatment of pancreatic cancer in the era of personalized medicine.

Contrast-enhanced CT Texture Parameters as Predictive Markers of High-risk Urodynamic Features in Adult Patients with Spina Bifida

ObjectiveTo investigate computed tomography (CT) texture analysis of the bladder wall as a predictor of urodynamics findings in adult patient with spina bifida. MethodsA single-center prospective trial was conducted from March 2015 to March 2017 including all consecutive adult spina bifida patients seen for urodynamic testing. A contrast-enhanced abdominal CT was systematically performed in all patients during the same visit. Texture features of the bladder wall related to the gray-level histogram and gray-level co-occurrence were evaluated on CT images. Multivariate analysis was performed to identify independent predictors of poor bladder compliance and detrusor overactivity among clinical and texture parameters. ResultsFourty patients were included. The Lasso penalized logistic regression analysis identified 2 texture parameters as potential predictors of poor bladder compliance: Skewness (coefficient weight, −1.81) and S.1.1.SumVarnc (coefficient weight, −3.52). Multivariate logistic regression analysis confirmed skewness (odds ratio [confidence interval 95%] = 0.40 [0.14, 0.97], P = .04) as an independent predictor of poor bladder compliance. The Lasso penalized logistic regression analysis identified one texture parameters as potential predictor of detrusor overactivity: Kurtosis (coefficient weight, −3.52), which was confirmed in multivariate logistic regression analysis (odds ratio [confidence interval 95%] = 1.12 [1.01, 1.55], P = .02). ConclusionOur findings demonstrate that CT texture analysis of the bladder wall might be an interesting tool to identify spina bifida patients with high risk urodynamic features.

Left superior pulmonary vein stump thrombosis and right renal infarction after left upper lobectomy: case report and literature review

Left upper lobectomy (LUL) has been considered to have a higher risk of thrombus formation in the pulmonary vein stump (PVS) than other lobectomies. A case of thrombus formation in the PVS and right renal infarction detected by contrast-enhanced computed tomography (CECT) 12days after LUL is presented. The thrombus in the PVS was considered to be related to the renal infarction because of the lack of other potential explanations. After intravenous heparin treatment for 1week and continuous oral anticoagulation, the thrombus in the PVS became smaller 3months after the operation, and it basically disappeared after 1year. Scar formation was detected in the area of renal infarction 3months after the operation, and no specific change was detected from then on. One should consider performing postoperative chest and abdominal CECT routinely within 1week after LUL, and, if thrombosis is found, antithrombotic therapy might then be given.

A dóziscsökkentés lehetőségei CT-képalkotás során az iteratív képrekonstrukció alkalmazásával

Introduction and aim: In case of imaging modalities using ionizing radiation, radiation exposure of the patients is a vital issue. It is important to survey the various dose-reducing techniques to achieve optimal radiation protection while keeping image quality on an optimal level. Method: We reprocessed 105 patients' data prospectively between February and April 2017. The determination of the radiation dose was based on the effective dose, calculated by multiplying the dose-length product (DLP) and dose-conversation coefficient. In case of image quality we used signal-to-noise ratio (SNR) based on manual segmentation of region of interest (ROI). For statistical analysis, one sample t-test and Wilcoxon signed rank test were used. Results: Using iterative reconstruction, the effective dose was significantly lower (p<0.001) in both native and contrast-enhanced abdominal, contrast-enhanced chest CT scans and in the case of the total effective dose. At native and contrast-enhanced abdominal CT scans, the noise content of the images showed significantly lower (p<0.001) values for iterative reconstruction images. At contrast-enhanced chest CT scans there was no significant difference between the noise content of the images (p>0.05). Conclusion: Using iterative reconstruction, it was possible to achieve significant dose reduction. Since the noise content of the images was not significantly higher using the iterative reconstruction compared to the filtered back projection, further dose reduction can be achievable while preserving the optimal quality of the images. Orv Hetil. 2019; 160(35): 1387-1394.