Artificial Intelligence Algorithm-Based Computerized Tomography Image Features Combined with Serum Tumor Markers for Diagnosis of Pancreatic Cancer.

The objective of this study was to analyze the value of artificial intelligence algorithm-based computerized tomography (CT) image combined with serum tumor markers for diagnoses of pancreatic cancer. In the study, 68 hospitalized patients with pancreatic cancer were selected as the experimental group, and 68 hospitalized patients with chronic pancreatitis were selected as the control group, all underwent CT imaging. An image segmentation algorithm on account of two-dimensional (2D)-three-dimensional (3D) convolution neural network (CNN) was proposed. It also introduced full convolutional network (FCN) and UNet network algorithm. The diagnostic performance of CT, serum carbohydrate antigen-50 (CA-50), serum carbohydrate antigen-199 (CA-199), serum carbohydrate antigen-242 (CA-242), combined detection of tumor markers, and CT-combined tumor marker testing (CT-STUM) for pancreatic cancer were compared and analyzed. The results showed that the average Dice coefficient of 2D-3D training was 84.27%, which was higher than that of 2D and 3D CNNs. During the test, the maximum and average Dice coefficient of the 2D-3D CNN algorithm was 90.75% and 84.32%, respectively, which were higher than the other two algorithms, and the differences were statistically significant (P < 0.05). The penetration ratio of pancreatic duct in the experimental group was lower than that in the control group, the rest were higher than that in the control group, and the differences were statistically significant (P < 0.05). CA-50, CA-199, and CA-242 in the experimental group were 141.72 U/mL, 1548.24 U/mL, and 83.65 U/mL, respectively, which were higher than those in the control group, and the differences were statistically significant (P < 0.05). The sensitivity, specificity, positive predictive value, and authenticity of combined detection of serum tumor markers were higher than those of CA-50, CA-199, and CA-242, and the differences were statistically significant (P < 0.05). The results showed that the proposed algorithm 2D-3D CNN had good stability and image segmentation performance. CT-STUM had high sensitivity and specificity in diagnoses of pancreatic cancer.

Judgement of the Clinical Value of Spiral CT Three-Dimensional Reconstruction in the Diagnosis of Lumbar Degenerative Osteoporosis.

With the aging of the population, there are more and more degenerative diseases of the lumbar spine that accompany osteoporosis. Lumbar degenerative osteoporosis has also become fragile and high in incidence, which has also attracted the attention of experts and scientists in related fields. Degeneration of the lumbar spine often causes pain in the waist and surrounding patients and even affects their life safety. The lesions such as the shoulders and lower back often show varying degrees of softening or induration in the fracture line or osteoporosis will directly produce adverse reactions to joint activities and then cause the development and deterioration of various complications. At present, spiral CT three-dimensional reconstruction technology has been widely used in the field of medical imaging and has played a very important role in the diagnosis and treatment of some diseases. Therefore, combined with three-dimensional reconstruction of spiral CT, this paper discusses its clinical value in the diagnosis of lumbar degenerative osteoporosis. In this experiment, in order to understand the image results after three-dimensional reconstruction, five groups of cases were selected for testing. The test items include the whole lesion site, vertebral imaging, soft tissue lesion site, and lumbar lesion site. In addition, in order to understand the clinical value of spiral CT three-dimensional reconstruction in the diagnosis of lumbar degenerative osteoporosis, this technique was compared and tested with other imaging methods. The selected imaging methods include X-ray, CT, and MRI. The test items include sensitivity, accuracy, positive predictive value, and negative predictive value. To explore the clinical value of spiral CT three-dimensional reconstruction in the diagnosis of lumbar degenerative osteoporosis, from the experimental results, the relevant image clarity and accuracy of the five groups of cases are high, the image quality after three-dimensional reconstruction is good, and the clarity and accuracy are high. In addition, the sensitivity and accuracy of spiral CT three-dimensional reconstruction are higher than those of other imaging methods. It has great clinical value in the diagnosis and treatment of lumbar degenerative osteoporosis.

Application and Evaluation of a 64-Slice CT Three-Dimensional Fusion Technique in the Determination of the Effective Ablation Margin after Radiofrequency Ablation of Hepatocellular Carcinoma.

Due to the low accuracy of traditional three-dimensional fusion technology in radiofrequency ablation of hepatocellular carcinoma, this paper studies the advantages of three-dimensional CT fusion technology over traditional two-dimensional imaging technology in preoperative visualization and radiofrequency ablation path selection of hepatocellular carcinoma. To study the prognostic differences of hepatocellular carcinoma patients with different ablation margins (AM) in the three groups, so as to explore the best AM value, so as to minimize the liver injury caused by radiofrequency ablation. The selected patients underwent CT plain scan and three-phase enhancement at 1, 3, 6, and 12 months after operation and were rechecked every 6 months. For recurrent patients, CT was rechecked every three months. The images were obtained by GE 64-slice spiral CT. The thickness of the reconstruction layer is 1 mm, and the interval is 1 mm. The reconstructed image is imported into 3D fusion software. The three-dimensional images of tumor focus, hepatic artery, portal vein, and hepatic vein were reconstructed by two experienced doctors by superimposing the saved tumor images, merging the vascular images into the display, and measuring the ablation boundary (AM value). The results showed that the recurrence rate in group A was higher than that in group B (P = 0.041), and there was no significant difference between group B and group C (P = 1.000). Compared with traditional two-dimensional imaging, three-dimensional CT fusion technology can display the anatomical structure and three-dimensional spatial relationship of tumors and blood vessels and select the best radiofrequency ablation path, so as to achieve accurate radiofrequency ablation.

Independent Association of Lipoprotein(a) and Coronary Artery Calcification With Atherosclerotic Cardiovascular Risk.

BACKGROUND: Elevated lipoprotein(a) [Lp(a)] and coronary artery calcium (CAC) score are individually associated with increased atherosclerotic cardiovascular disease (ASCVD) risk but have not been studied in combination. OBJECTIVES: This study sought to investigate the independent and joint association of Lp(a) and CAC with ASCVD risk. METHODS: Plasma Lp(a) and CAC were measured at enrollment among asymptomatic participants of the MESA (Multi-Ethnic Study of Atherosclerosis) (n = 4,512) and DHS (Dallas Heart Study) (n = 2,078) cohorts. Elevated Lp(a) was defined as the highest race-specific quintile, and 3 CAC score categories were studied (0, 1-99, and ≥100). Associations of Lp(a) and CAC with ASCVD risk were evaluated using risk factor-adjusted Cox regression models. RESULTS: Among MESA participants (61.9 years of age, 52.5% women, 36.8% White, 29.3% Black, 22.2% Hispanic, and 11.7% Chinese), 476 incident ASCVD events were observed during 13.2 years of follow-up. Elevated Lp(a) and CAC score (1-99 and ≥100) were independently associated with ASCVD risk (HR: 1.29; 95% CI: 1.04-1.61; HR: 1.68; 95% CI: 1.30-2.16; and HR: 2.66; 95% CI: 2.07-3.43, respectively), and Lp(a)-by-CAC interaction was not noted. Compared with participants with nonelevated Lp(a) and CAC = 0, those with elevated Lp(a) and CAC ≥100 were at the highest risk (HR: 4.71; 95% CI: 3.01-7.40), and those with elevated Lp(a) and CAC = 0 were at a similar risk (HR: 1.31; 95% CI: 0.73-2.35). Similar findings were observed when guideline-recommended Lp(a) and CAC thresholds were considered, and findings were replicated in the DHS. CONCLUSIONS: Lp(a) and CAC are independently associated with ASCVD risk and may be useful concurrently for guiding primary prevention therapy decisions.

The Value of CT Angiography Based on Intelligent Segmentation Algorithm for Survival of Hemodialysis Patients.

This study was to explore the application value for central venous stenosis and occlusion in hemodialysis patients under the CT angiography based on intelligent segmentation algorithm, so that patients can survive better. Spiral CT was used to examine upper limb swelling in 62 uremic hemodialysis patients at a speed of 3.8 mL/s. Nonionic iodine contrast agent was injected around the contralateral limb. The total dosage of 90-102 mL, it was scanned by intelligent trigger technology. The trigger scanning threshold was set. The monitoring point was located in the superior vena cava. CT with convolutional neural network intelligent segmentation algorithm was used to process image data. Finally, the quality of life and related biochemical levels of patients before and after hemodialysis were detected. Under the CT angiography of intelligent segmentation algorithm, 77 stenoses were found in 62 uremic patients, including 48 stenoses of the brachial vein and 17 stenoses of the superior vena cava. The correlation coefficient between CT angiography and digital subtraction angiography (DSA) imaging results of intelligent segmentation algorithm was 0.411. Segmentation effect of the algorithm in this study: automatic segmentation accuracy was greater than 79%. After hemodialysis treatment, the scores of physical fitness, pain, social function, and energy status of patients were significantly increased compared with those before treatment, and the levels of albumin, serum phosphorus, and parathyroid hormone were significantly decreased (P < 0.05). In summary, CT angiography with intelligent segmentation algorithm can obtain clear, intuitive, and complete vascular walking images, and better display subclavian vein, brachiocephalic vein, and superior vena cava. It can provide more valuable support for surgical intervention and has certain application value for better survival of hemodialysis patients.

Intelligent Algorithm-Based Multislice Spiral Computed Tomography to Diagnose Coronary Heart Disease.

In this study, dictionary learning and expectation maximization reconstruction (DLEM) was combined to denoise 64-slice spiral CT images, and results of coronary angiography (CAG) were used as standard to evaluate its clinical value in diagnosing coronary artery diseases. 120 patients with coronary heart disease (CHD) confirmed by CAG examination were retrospectively selected as the research subjects. According to the random number table method, the patients were divided into two groups: the control group was diagnosed by conventional 64-slice spiral CT images, and the observation group was diagnosed by 64-slice spiral CT images based on the DLEM algorithm, with 60 cases in both groups. With CAG examination results as the standard, the diagnostic effects of the two CT examination methods were compared. The results showed that when the number of iterations of maximum likelihood expectation maximization (MLEM) algorithm reached 50, the root mean square error (RMSE) and peak signal to noise ratio (PSNR) values were similar to the results obtained by the DLEM algorithm under a number of iterations of 10 when the RMSE and PSNR values were 18.9121 dB and 74.9911 dB, respectively. In the observation group, 28.33% (17/60) images were of grade 4 or above before processing; after processing, it was 70% (42/60), significantly higher than the proportion of high image quality before processing. The overall diagnostic consistency, sensitivity, specificity, and accuracy (88.33%, 86.67%, 80%, and 85%) of the observation group were better than those in the control group (60.46%, 62.5%, 58.33%, and 61.66%). In conclusion, the DLEM algorithm has good denoising effect on 64-slice spiral CT images, which significantly improves the accuracy in the diagnosis of coronary artery stenosis and has good clinical diagnostic value and is worth promoting.

Multislice Spiral Computed Tomography Postprocessing Technology in the Imaging Diagnosis of Extremities and Joints.

OBJECTIVE: To improve the clinical detection rate of bone and joint fractures of the extremities and to explore the value and significance of the application of multislice spiral computed tomography (MSCT) postprocessing technology in diagnosis. METHODS: 80 patients with bone and joint fractures of the extremities admitted to the hospital were selected as the research objects. The patients received X-ray digital radiography (DR) plain film examination and then MSCT examination. At the same time, multiplane reconstruction (MPR) and surface shadow display (SSD) and volume rendering three-dimensional imaging (VRT) technology and other postprocessing technologies compare the differences in the detection rate of limbs and joint fractures between the two inspection methods. RESULTS: A total of 100 fractures were found in 80 patients. The detection rate of X-ray DR was 69%. After MSCT postprocessing technology, the detection rates of MPR, SSD, and VRT were 96%, 98%, and 99%, respectively. The accuracy of MSCT postprocessing technology in diagnosing extremity bone and joint fractures was significantly higher than that of DR, and the difference between groups was statistically significant. CONCLUSION: MSCT postprocessing technology for patients with extremity bone and joint fractures has a good effect. It is not only noninvasive but also has a high detection rate. It can significantly reduce the missed and misdiagnosed rate and provide detailed imaging data for the formulation of clinical treatment plans.

Lipoprotein(a) is robustly associated with aortic valve calcium.

OBJECTIVES: To investigate the prevalence and quantity of aortic valve calcium (AVC) in two large cohorts, stratified according to age and lipoprotein(a) (Lp(a)), and to assess the association between Lp(a) and AVC. METHODS: We included 2412 participants from the population-based Rotterdam Study (52% women, mean age=69.6±6.3 years) and 859 apparently healthy individuals from the Amsterdam University Medical Centers (UMC) outpatient clinic (57% women, mean age=45.9±11.6 years). All individuals underwent blood sampling to determine Lp(a) concentration and non-enhanced cardiac CT to assess AVC. Logistic and linear regression analyses were performed to investigate the associations of Lp(a) with the presence and amount of AVC. RESULTS: The prevalence of AVC was 33.1% in the Rotterdam Study and 5.4% in the Amsterdam UMC cohort. Higher Lp(a) concentrations were independently associated with presence of AVC in both cohorts (OR per 50 mg/dL increase in Lp(a): 1.54 (95% CI 1.36 to 1.75) in the Rotterdam Study cohort and 2.02 (95% CI 1.19 to 3.44) in the Amsterdam UMC cohort). In the Rotterdam Study cohort, higher Lp(a) concentrations were also associated with increase in aortic valve Agatston score (ß 0.19, 95% CI 0.06 to 0.32 per 50 mg/dL increase). CONCLUSIONS: Lp(a) is robustly associated with presence of AVC in a wide age range of individuals. These results provide further rationale to assess the effect of Lp(a) lowering interventions in individuals with early AVC to prevent end-stage aortic valve stenosis.

The role of trans-thoracic echocardiography in the assessment of aortic annular diameter.

ABSTRACT: We aimed to compare two-dimension transthoracic echocardiogram (2D-TTE) and three-dimension transthoracic echocardiogram (3D-TTE) measurements of the aortic annular diameter using multi-detector CT (MDCT) as a gold standard.This prospective observational study included 50 consecutive patients who came to the cardiology department, Al-Azhar University Hospital, New Damietta, for MDCT coronary angiography. The study was carried out in the period from July 2016 until February 2017. All patients were subjected to informed consent, clinical history, physical examination, transthoracic echocardiography 2D and 3D, and MDCT.The aortic annular areas measured by MDCT and 3D-TTE were significantly larger than areas by 2D-TTE. A good correlation (r = 0.82) was observed between the areas obtained by 3D-TTE and MDCT; however, the correlation between the values by 2D-TTE and MDCT was rough (r = 0.30). Eccentricity Index (EI) values in 28% of the patients were greater than 0.1, that is, the aortic annulus was elliptical.Accuracy of aortic annular diameter measurement by 3D-TTE was superior to that by 2D-TTE. Three-D TTE and MDCT revealed that the shape of the aortic annulus was elliptical in 28% to 30% respectively of study subjects. There is a strong concordance between the minimum and the maximum diameter determine by 3D-TTE and MDCT.

Implementation of Institutional Triaging Algorithms Decreases Head and Neck MDCT Use in Blunt Trauma.

Background Multidetector CT (MDCT) enables rapid and accurate diagnosis of head and neck (HN) injuries in patients with blunt trauma (BT). However, MDCT is overused, and appropriate selection of patients for imaging could improve workflow. Purpose To investigate the effect of implementing clinical triaging algorithms on use of MDCT in the HN in patients who have sustained BT. Materials and Methods In this retrospective study, patients aged 15 years or older with BT admitted between October 28, 2007, and December 31, 2013, were included. Patients were divided into pre- and postalgorithm groups. The institutional trauma registry and picture archiving and communication system reports were reviewed to determine which patients underwent MDCT of the head, MDCT of the cervical spine (CS), and MDCT angiography of the HN at admission and whether these examinations yielded positive results. Injury Severity Score, Acute Physiology and Chronic Health Evaluation II score (only those patients in the intensive care unit), length of hospital stay (LOS), length of intensive care unit stay (ICULOS), and mortality were obtained from the trauma registry. Results A total of 8999 patients (mean age, 45 years ± 20 [standard deviation]; age range, 15-101 years; 6027 male) were included in this study. A lower percentage of the postalgorithm group versus the prealgorithm group underwent MDCT of the head (55.8% [2774 of 4969 patients]; 95% CI: 54.4, 57.2 vs 64.2% [2589 of 4030 patients]; 95% CI: 62.8, 65.7; P < .001) and CS (49.4% [2452 of 4969 patients]; 95% CI: 48.0, 50.7 vs 60.5% [2438 of 4030 patients]; 95% CI: 59.0, 62.0; P < .001) but not MDCT angiography of the HN (9.7% [480 of 4969 patients]; 95% CI: 8.9, 10.5 vs 9.8% [393 of 4030 patients]; 95% CI: 8.9, 10.7; P > .99). Pre- versus postalgorithm groups did not differ in LOS (mean, 4.8 days ± 7.1 vs 4.5 days ± 7.1, respectively; P = .42), ICULOS (mean, 4.6 days ± 6.6 vs 4.8 days ± 6.7, respectively; P > .99), or mortality (2.9% [118 of 4030 patients]; 95% CI: 2.5, 3.5; vs 2.8% [141 of 4969 patients]; 95% CI: 2.4, 3.3; respectively; P > .99). Conclusion Implementation of a clinical triaging algorithm resulted in decreased use of multidetector CT of the head and cervical spine in patients who experienced blunt trauma, without increased adverse outcomes. © RSNA, 2021 See also the editorial by Munera and Martin in this issue.

Multidetector computed tomography utilization in an urban sub-Saharan Africa setting: user characteristics, indications and appropriateness.

INTRODUCTION: multidetector computed tomography (MDCT) is a widely used cross-sectional imaging modality despite increasing concerns about radiation exposure and overuse. The aim of this study was to describe the socio-demographic characteristics of MDCT users in an urban city in Cameroon and to assess the clinical indications for appropriateness. METHODS: we conducted a survey of MDCT users and collected data on demographic attributes and socialization patterns, clinical indications for MDCT and time to obtain MDCT. MDCT appropriateness was assessed using the American College of Radiologists Appropriateness Criteria®. Frequencies, percentages, odds ratios and 95% confidence intervals were used to summarize the data. RESULTS: with a response rate of 79%, 511 MDCT users were surveyed. The mean (standard deviation) age was 45(19) years and male to female sex ratio 1:1. Seventy-eight percent (95% confidence interval [CI]: 74-83%) of respondents reported not having any health insurance. Head scans accounted for 52% (95%CI: 47-56%) of all scans with trauma (19% [95%CI: 15-22%]), low back pain (18% [95%CI: 14-21%]) and suspected stroke (10% [95%CI: 7-13%]) being the most frequent indications. Sixteen percent (95%CI: 13-20%) of the scans were judged to be inappropriate. Predictors of MDCT appropriateness after multivariable logistic regression modeling were age (aOR=0.97; P=0.009; 95%CI=0.94-0.99), health insurance ownership (aOR=0.40; P=0.034; 95%CI=0.18-0.94) and being referred by non-specialist physicians (aOR=0.20; P<0.001; 95%CI=0.09-0.47). CONCLUSION: people from all social strata use MDCT, mostly appropriately and especially for head scans after trauma in this urban setting. However, the proportion of inappropriate studies was considerable suggesting the need for control measures.

Duodenal tumors on cross-sectional imaging with emphasis on multidetector computed tomography: a pictorial review.

Duodenal tumours are uncommon, but they can cause significant morbidity and mortality. As stomach and colon are a more common site of gastrointestinal malignancies, radiologists sometimes neglect the duodenum. Multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) can accurately locate and characterize mass-forming duodenal lesions, making them invaluable for the differential diagnosis and determining management strategies such as biopsy or surgery. Although conventional endoscopy continues to play an important role in the diagnosis of duodenal tumors, MDCT and MRI are very useful for evaluating the duodenal wall, extraduodenal space, and surrounding viscera, as well as the intraluminal content seen on endoscopy. This pictorial review aims to illustrate the most common benign and malignant mass-forming duodenal lesions and to focus on the imaging features that are most helpful in reaching the correct diagnosis.

Impact of leaflet thrombosis on hemodynamics and clinical outcomes after bioprosthetic aortic valve replacement: A meta-analysis.

BACKGROUND: Leaflet thrombosis (LT, also called cusp thrombosis) detected by multidetector computed tomography (MDCT) is common in bioprosthetic aortic valve replacement (bAVR). However, it remains contradictory whether MDCT-defined LT following bAVR is associated with hemodynamic deterioration and stroke. Thus, we performed the first meta-analysis to assess hemodynamic outcomes and updated the latest researches on the clinical outcomes of MDCT-defined LT after bAVR. HYPOTHESIS: MDCT-defined LT might be associated with worse hemodynamic and clinical outcomes after bAVR. METHOD: MEDLINE, EMBASE, Cochrane Library, and ClinicalTrial.gov were searched from inception to 15th April 2019. The fix-effect model was utilized to calculate odds ratio (OR) and 95% confidence interval (CI). The primary outcomes were hemodynamic stability indexes, including mean pressure gradient (MPG), left ventricular ejection fraction (LVEF), paravalvular leak (PVL), and clinical heart failure. The secondary endpoints were major adverse cardiovascular and cerebrovascular events (MACCEs), which consisted of myocardial infarction, all-cause death, stroke, and transient ischemic attack (TIA). RESULTS: Twelve studies with 4820 patients were included. The total prevalence of MDCT-defined LT was 9.7%. MDCT-defined LT was associated with a significantly increased risk of MPG (inverse variance 0.43, 95% CI: [0.30, 0.57]), MACCEs (OR 2.43, 95% CI: [1.45, 4.06]), stroke (OR 1.79, 95% CI: [1.03, 3.11]), and TIA (OR 4.09, 95% CI: [1.59, 10.54]). There were no differences for other outcomes. CONCLUSIONS: MDCT-defined LT after bAVR is associated with increased MPG and increased risk of adverse cerebrovascular events, including TIA and stroke. While LVEF, PVL, and clinical heart failure were similar between patient with and without LT.

Computed tomography angiography is not accurate in predicting surgical prosthetic aortic valve implant size.

BACKGROUND: Multidetector computed tomography is vital in preoperative sizing for transcatheter aortic valve replacement. The purpose of this study is to determine whether preoperative transcatheter aortic valve replacement multidetector computed tomography accurately predicts surgical aortic valve prosthesis size. METHODS: Between July 2012 and July 2017, 102 patients who underwent surgical aortic valve replacement had preoperative aortic valve sizing by multidetector computed tomography. The aortic annulus diameter calculated using multidetector computed tomography was compared with intraoperative valve sizing during surgical aortic valve replacement. RESULTS: Forty-one (40.2%) of the 102 patients studied had multidetector computed tomography aortic valve measurements that were accurate. Implanted valves were smaller than multidetector computed tomography calculation in 40 patients (39.2%) and were larger in 21 patients (20.6%). Multidetector computed tomography measurements remained inconsistent with intraoperative sizing regardless of aortic annulus diameter. The variance between multidetector computed tomography annulus measurements and intraoperative sizing was statistically significant. CONCLUSIONS: Preoperative aortic annulus measurements by our institutional transcatheter aortic valve replacement multidetector computed tomography protocol differed substantially from surgical implant size. There was no trend toward over nor under sizing for the entire cohort. However, patients with large measured annulus diameter were more likely to have a smaller valve implanted than predicted, and patients with small measured annulus diameter were more likely to have a larger valve implanted than predicted. These results may affect preoperative planning for patients undergoing aortic valve replacement.

Preoperative Evaluation of Liver Parenchyma of Potential Donors in Living Donor Liver Transplantation.

BACKGROUND: Hepatic steatosis carries a risk of postoperative liver dysfunction in donors and graft nonfunction in recipients. This article discusses the evaluation of fatty infiltration in donor liver parenchyma on multidetector computed tomography. MATERIALS AND METHODS: The methods of hepatic fat estimation include measurement of hepatic attenuation in HU and calculation of the liver attenuation index (LAI). Liver attenuation values reflect the degree of steatosis. Average attenuation of liver parenchyma is calculated by placing the circular region of interest of at least 1 cm2 area at multiple places in the liver on noncontrast CT images. Splenic attenuation is measured by placing the circular region of interest at its upper, middle, and lower poles. The LAI is the difference between mean hepatic attenuation and mean splenic attenuation. RESULTS: A total of 52 donors were evaluated as potential recipients (34 men, 18 women; mean age, 33.2 years; range, 23-55 years). In 34 donors liver attenuation index (LAI) values were from 2 HU to 22 HU. An LAI > 5 HU correctly predicted the absence of significant macrovesicular steatosis. These donors were acceptable for a liver transplant. The LAI values of -10 to 5 HU were suggestive of mild to moderate steatosis (6%-30%); 18 (34.6%) volunteers did not proceed to donation because of negative LAI < -5 HU. In 2 cases with LAI of -7 and LAI of -8 liver biopsy was performed, and 30% steatosis was confirmed in the pathohistologic examination. Unacceptable liver biopsy result was considered as contraindication for donation. The LAI values of < -10 HU were suggestive of moderate to severe hepatic steatosis of 30% or greater. In these cases liver biopsy is not needed, as such donors are not acceptable for liver transplant. CONCLUSION: Computed tomography imaging provides a detailed evaluation of fatty infiltration in donor liver parenchyma.

Importance of Multislice Computed Tomography in Determining the Severity of Chronic Liver Disease State.

BACKGROUND: In the present study, we aimed to put forward the relationship between multidetector computed tomography findings and scores for liver function evaluation. METHOD: Included in the study were 51 patients with liver cirrhosis. Preoperative creatinine levels, international normalized ratio and alpha-fetoprotein values, albumin and sodium levels, the presence of ascites and varices, Model for End-Stage Liver Disease (MELD) scores, MELD-Sodium (MELD-Na) scores, and Child-Turcotte-Pugh Classification, the presence of ascites and varices, the size of liver, the size and diameter of the spleen, portal vein diameter, splenic artery diameter, and proper hepatic and right hepatic artery diameter were all determined. RESULTS: Although the correlation between the spleen diameter and the MELD scores (P <.001) and MELD-Na scores (P = .02) was strong, there was no association with the Child-Turcotte-Pugh Classification (P = .08). Despite the correlations between portal vein diameter (P = .04) and splenic artery diameter (P = .04) and MELD scores, no association was detected with MELD-Na scores and the Child-Pugh scores. Even though a negative correlation between proper hepatic artery diameter (P = .18) and MELD-Na scores was noted, no statistically significant correlation could be identified with any scoring systems. In the multivariate linear regression analyses, the correlation between the portal vein diameter and MELD scores was significant as a radiologic finding. In the multiple linear regression analyses, the negative correlation between the right hepatic artery and MELD-Na scores diameter was statistically significant. In the multiple linear regression analyses, there was no statistically significant correlation between preoperative radiologic findings and Child-Turcotte-Pugh Classification. CONCLUSION: We believe that preoperative multislice computed tomography imaging in patients with chronic liver disease may contribute to the diagnosis of disease, the determination of vascular anomalies, and the grading of the severity of the disease.

Whole-body computed tomography: a new point of view in a hospital check-up unit? Our experience in 6516 patients.

BACKGROUND: There is a growing awareness that prevention and early diagnosis may reduce the high mortality associated with cancer, cardiovascular and other diseases. The role of whole-body computed tomography (WB-CT) in self-referred and asymptomatic patients has been debated. AIM: To determine frequency and spectrum of WB-CT findings in average-risk subjects derived from a Medical-Check-Up-Unit, to evaluate recommendations reported and distribution according to sex and age-groups. MATERIALS AND METHODS: We retrospectively reviewed 6516 subjects who underwent WB-CT (June 2004/February 2015). All were > 40 years and referred by Medical-Check-Up-Unit of our hospital. The main findings were categorized and classified as normal or not. Its distribution according to sex and age-groups was evaluated using Chi-square test and linear-by-linear association test, respectively. Number of recommendations, type and interval of follow-up were recorded. Descriptive statistics were used. RESULTS: WB-CT performed in 6516 patients (69% men, 31% women, mean age = 58.4 years) revealed chest (81.4%), abdominal (93.06%) and spine (65.39%) abnormalities. Only 1.60% had completely normal exploration. Abnormal WB-CT in men was significantly higher than women (98.64% vs. 97.87%; p = 0.021), with significant increase as age was higher (40-49 years: 95.65%; 50-59 years: 98.33%; 60-69 years: 99.47%; > 69 years: 99.89%) (p < 0.001). Although most findings were benign, we detected 1.47% primary tumors (96, mainly 35 kidneys and 15 lungs). 17.39% of patients received at least one recommendation predominantly in chest (78.19%) and follow-up imaging (69.89%). CONCLUSION: The most common WB-CT findings in asymptomatic subjects are benign. However, this examination allows identifying an important number of relevant and precocious findings that significantly increase with age, involving changes in lifestyle and precocious treatment.

Impact of Valve Over-Sizing After Transcatheter Aortic Valve Implantation With a Self-Expanding Valve: A Multislice Computed Tomography Study.

BACKGROUND: In transcatheter aortic valve implantation (TAVI), prosthesis over-sizing prevents paravalvular leak (PVL). Strategies of over-sizing for self-expanding bioprostheses are not well established at present. METHODS: Patients with aortic valve stenosis scheduled for TAVI underwent preprocedural multislice computed tomography. Based on the degree of over-sizing, a ROC curve was drawn to define the optimal value of valve sizing for reducing PVL after TAVI. RESULTS: A total of 152 consecutive patients were included in the study (mean age, 79.95 ± 7.71 years; log EuroScore: 23.87 ± 8.93%). Based on the ROC curve, sizing of 14% was the optimal that would lead to less moderate/severe PVL (P<.01). Group 1 was defined as sizing <14% (n = 49 patients) and group 2 was defined as sizing ≥14% (n = 103 patients). During a follow-up period of 36 ± 14 months, a total of 9 patients died from group 1 vs 4 patients from group 2 (P<.01). Two of the patients who died had moderate/severe PVL and 11 had no/mild PVL (P=.27). From the population, a total of 49 patients (32%) were found to be in the "borderline" zone. Patients who received the smaller valve had lower mean left ventricular outflow tract diameter (P=.048), higher rate of calcium load (mild: 10 [32%] vs 13 [72%]; moderate: 16 [52%] vs 3 [17%]; severe: 5 [16%] vs 2 [11%]; P=.02) and lower mean of sinus of Valsalva diameter (P=.046) compared with patients who received the bigger valve. CONCLUSIONS: In patients undergoing TAVI, over-sizing the prosthesis at least 14% reduces PVL. In borderline cases, taking into consideration additional anatomical parameters may result in low rates of PVL.

Tensor framelet based iterative image reconstruction algorithm for low-dose multislice helical CT.

In this study, we investigate the feasibility of improving the imaging quality for low-dose multislice helical computed tomography (CT) via iterative reconstruction with tensor framelet (TF) regularization. TF based algorithm is a high-order generalization of isotropic total variation regularization. It is implemented on a GPU platform for a fast parallel algorithm of X-ray forward band backward projections, with the flying focal spot into account. The solution algorithm for image reconstruction is based on the alternating direction method of multipliers or the so-called split Bregman method. The proposed method is validated using the experimental data from a Siemens SOMATOM Definition 64-slice helical CT scanner, in comparison with FDK, the Katsevich and the total variation (TV) algorithm. To test the algorithm performance with low-dose data, ACR and Rando phantoms were scanned with different dosages and the data was equally undersampled with various factors. The proposed method is robust for the low-dose data with 25% undersampling factor. Quantitative metrics have demonstrated that the proposed algorithm achieves superior results over other existing methods.