Skeletal muscle protein turnover responses to parenteral nutrition in patients with alcoholic liver cirrhosis and sarcopenia.

Alcoholic liver cirrhosis (ALC) is accompanied by sarcopenia. The aim of this study was to investigate the acute effects of balanced parenteral nutrition (PN) on skeletal muscle protein turnover in ALC. Eight male patients with ALC and seven age- and sex-matched healthy controls were studied for 3 h of fasting followed by 3 h of intravenous PN (SmofKabiven 1,206 mL: amino acid = 38 g, carbohydrates = 85 g, and fat = 34 g) 4 mL/kg/h. We measured leg blood flow and sampled paired femoral arteriovenous concentrations and quadriceps muscle biopsies while providing a primed continuous infusion of [ring-2d5]-phenylalanine to quantify muscle protein synthesis and breakdown. Patients with ALC exhibited shorter 6-min walking distance (ALC: 487 ± 38 vs. controls: 722 ± 14 m, P < 0.05), lower hand-grip strength (ALC: 34 ± 2 vs. controls: 52 ± 2 kg, P < 0.05), and computed tomography (CT)-verified leg muscle loss (ALC: 5,922 ± 246 vs. controls: 8,110 ± 345 mm2, P < 0.05). Net leg muscle phenylalanine uptake changed from negative (muscle loss) during fasting to positive (muscle gain) in response to PN (ALC: -0.18 ± +0.01 vs. 0.24 ± 0.03 µmol/kg muscle·min-1; P < 0.001 and controls: -0.15 ± 0.01 vs. 0.09 ± 0.01 µmol/kg muscle·min-1; P < 0.001) but with higher net muscle phenylalanine uptake in ALC than controls (P < 0.001). Insulin concentrations were substantially higher in patients with ALC during PN. Our results suggest a higher net muscle phenylalanine uptake during a single infusion of PN in stable patients with ALC with sarcopenia compared with healthy controls.NEW & NOTEWORTHY Muscle protein turnover responses to parenteral nutritional (PN) supplementation have not previously been studied in stable alcoholic liver cirrhosis (ALC). We applied stable isotope tracers of amino acids to directly quantify net muscle protein turnover responses to PN in sarcopenic males with ALC and healthy controls. We found a higher net muscle protein gain in ALC during PN, thereby providing the physiological rationale for future clinical trials of PN as a potential countermeasure to sarcopenia.

The interaction between metformin and physical activity on postprandial glucose and glucose kinetics: a randomised, clinical trial.

AIMS/HYPOTHESIS: The aim of this parallel-group, double-blinded (study personnel and participants), randomised clinical trial was to assess the interaction between metformin and exercise training on postprandial glucose in glucose-intolerant individuals. METHODS: Glucose-intolerant (2 h OGTT glucose of 7.8-11.0 mmol/l and/or HbA1c of 39-47 mmol/mol [5.7-6.5%] or glucose-lowering-medication naive type 2 diabetes), overweight/obese (BMI 25-42 kg/m2) individuals were randomly allocated to a placebo study group (PLA, n = 15) or a metformin study group (MET, n = 14), and underwent 3 experimental days: BASELINE (before randomisation), MEDICATION (after 3 weeks of metformin [2 g/day] or placebo treatment) and TRAINING (after 12 weeks of exercise training in combination with metformin/placebo treatment). Training consisted of supervised bicycle interval sessions with a mean intensity of 64% of Wattmax for 45 min, 4 times/week. The primary outcome was postprandial glucose (mean glucose concentration) during a mixed meal tolerance test (MMTT), which was assessed on each experimental day. For within-group differences, a group × time interaction was assessed using two-way repeated measures ANOVA. Between-group changes of the outcomes at different timepoints were compared using unpaired two-tailed Student's t tests. RESULTS: Postprandial glucose improved from BASELINE to TRAINING in both the PLA group and the MET group (∆PLA: -0.7 [95% CI -1.4, 0.0] mmol/l, p = 0.05 and ∆MET: -0.7 [-1.5, -0.0] mmol/l, p = 0.03), with no between-group difference (p = 0.92). In PLA, the entire reduction was seen from MEDICATION to TRAINING (-0.8 [-1.3, -0.1] mmol/l, p = 0.01). Conversely, in MET, the entire reduction was observed from BASELINE to MEDICATION (-0.9 [-1.6, -0.2] mmol/l, p = 0.01). The reductions in mean glucose concentration during the MMTT from BASELINE to TRAINING were dependent on differential time effects: in the PLA group, a decrease was observed at timepoint (t) = 120 min (p = 0.009), whereas in the MET group, a reduction occurred at t = 30 min (p < 0.001). V̇O2peak increased 15% (4.6 [3.3, 5.9] ml kg-1 min-1, p < 0.0001) from MEDICATION to TRAINING and body weight decreased (-4.0 [-5.2, -2.7] kg, p < 0.0001) from BASELINE to TRAINING, with no between-group differences (p = 0.7 and p = 0.5, respectively). CONCLUSIONS/INTERPRETATION: Metformin plus exercise training was not superior to exercise training alone in improving postprandial glucose. The differential time effects during the MMTT suggest an interaction between the two modalities. FUNDING: The Beckett foundation, A.P Møller Foundation, DDA, the Research Foundation of Rigshospitalet and Trygfonden. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03316690). Graphical abstract.

The efficacy of using computer-aided detection (CAD) for detection of breast cancer in mammography screening: a systematic review.

BACKGROUND: Early detection of breast cancer (BC) is crucial in lowering the mortality. PURPOSE: To present an overview of studies concerning computer-aided detection (CAD) in screening mammography for early detection of BC and compare diagnostic accuracy and recall rates (RR) of single reading (SR) with SR + CAD and double reading (DR) with SR + CAD. MATERIAL AND METHODS: PRISMA guidelines were used as a review protocol. Articles on clinical trials concerning CAD for detection of BC in a screening population were included. The literature search resulted in 1522 records. A total of 1491 records were excluded by abstract and 18 were excluded by full text reading. A total of 13 articles were included. RESULTS: All but two studies from the SR vs. SR + CAD group showed an increased sensitivity and/or cancer detection rate (CDR) when adding CAD. The DR vs. SR + CAD group showed no significant differences in sensitivity and CDR. Adding CAD to SR increased the RR and decreased the specificity in all but one study. For the DR vs. SR + CAD group only one study reported a significant difference in RR. CONCLUSION: All but two studies showed an increase in RR, sensitivity and CDR when adding CAD to SR. Compared to DR no statistically significant differences in sensitivity or CDR were reported. Additional studies based on organized population-based screening programs, with longer follow-up time, high-volume readers, and digital mammography are needed to evaluate the efficacy of CAD.

Glucose turnover at whole-body and skeletal muscle level in response to parenteral nutrition in male patients with alcoholic liver cirrhosis.

BACKGROUND & AIMS: Cirrhosis is associated with insulin resistance and impaired glucose tolerance, which may be caused by impairments at different tissue levels (liver, skeletal muscle, and/or beta cell). METHODS: Here, glucose kinetics at whole-body and skeletal muscle level in patients with cirrhosis (Child-Pugh A and B) were studied during parenteral nutrition using the isotope dilution technique and arteriovenous balance approach across the leg. As opposed to the euglycemic hyperinsulinemic clamp or glucose tolerance tests applied in previous studies, this approach provides a nutrient composition more similar to a normal meal while circumventing any possible portal-systemic shunting, impaired hepatic uptake and incretin effect. RESULTS: We confirmed the presence of hepatic and peripheral insulin resistance in our patient population. Endogenous glucose production was less suppressed in response to parenteral nutrition. However, glucose uptake in skeletal muscle was increased. CONCLUSION: Our results suggests that in our study participants with cirrhosis, the hepatic and peripheral insulin resistance is compensated for by increased insulin secretion and thus, increased glucose uptake in muscle. Hereby, glucose homeostasis is maintained.

Performance and Agreement When Annotating Chest X-ray Text Reports-A Preliminary Step in the Development of a Deep Learning-Based Prioritization and Detection System.

A chest X-ray report is a communicative tool and can be used as data for developing artificial intelligence-based decision support systems. For both, consistent understanding and labeling is important. Our aim was to investigate how readers would comprehend and annotate 200 chest X-ray reports. Reports written between 1 January 2015 and 11 March 2022 were selected based on search words. Annotators included three board-certified radiologists, two trained radiologists (physicians), two radiographers (radiological technicians), a non-radiological physician, and a medical student. Consensus labels by two or more of the experienced radiologists were considered "gold standard". Matthew's correlation coefficient (MCC) was calculated to assess annotation performance, and descriptive statistics were used to assess agreement between individual annotators and labels. The intermediate radiologist had the best correlation to "gold standard" (MCC 0.77). This was followed by the novice radiologist and medical student (MCC 0.71 for both), the novice radiographer (MCC 0.65), non-radiological physician (MCC 0.64), and experienced radiographer (MCC 0.57). Our findings showed that for developing an artificial intelligence-based support system, if trained radiologists are not available, annotations from non-radiological annotators with basic and general knowledge may be more aligned with radiologists compared to annotations from sub-specialized medical staff, if their sub-specialization is outside of diagnostic radiology.

Four-Dimensional Flow MRI of Abdominal Veins: A Systematic Review.

The aim of this systematic review is to provide an overview of the use of Four-Dimensional Magnetic Resonance Imaging of vector blood flow (4D Flow MRI) in the abdominal veins. This study was composed according to the PRISMA guidelines 2009. The literature search was conducted in MEDLINE, Cochrane Library, EMBASE, and Web of Science. Quality assessment of the included studies was performed using the QUADAS-2 tool. The initial search yielded 781 studies and 21 studies were included. All studies successfully applied 4D Flow MRI in abdominal veins. Four-Dimensional Flow MRI was capable of discerning between healthy subjects and patients with cirrhosis and/or portal hypertension. The visual quality and inter-observer agreement of 4D Flow MRI were rated as excellent and good to excellent, respectively, and the studies utilized several different MRI data sampling strategies. By applying spiral sampling with compressed sensing to 4D Flow MRI, the blood flow of several abdominal veins could be imaged simultaneously in 18-25 s, without a significant loss of visual quality. Four-Dimensional Flow MRI might be a useful alternative to Doppler sonography for the diagnosis of cirrhosis and portal hypertension. Further clinical studies need to establish consensus regarding MRI sampling strategies in patients and healthy subjects.

The Added Effect of Artificial Intelligence on Physicians' Performance in Detecting Thoracic Pathologies on CT and Chest X-ray: A Systematic Review.

Our systematic review investigated the additional effect of artificial intelligence-based devices on human observers when diagnosing and/or detecting thoracic pathologies using different diagnostic imaging modalities, such as chest X-ray and CT. Peer-reviewed, original research articles from EMBASE, PubMed, Cochrane library, SCOPUS, and Web of Science were retrieved. Included articles were published within the last 20 years and used a device based on artificial intelligence (AI) technology to detect or diagnose pulmonary findings. The AI-based device had to be used in an observer test where the performance of human observers with and without addition of the device was measured as sensitivity, specificity, accuracy, AUC, or time spent on image reading. A total of 38 studies were included for final assessment. The quality assessment tool for diagnostic accuracy studies (QUADAS-2) was used for bias assessment. The average sensitivity increased from 67.8% to 74.6%; specificity from 82.2% to 85.4%; accuracy from 75.4% to 81.7%; and Area Under the ROC Curve (AUC) from 0.75 to 0.80. Generally, a faster reading time was reported when radiologists were aided by AI-based devices. Our systematic review showed that performance generally improved for the physicians when assisted by AI-based devices compared to unaided interpretation.

The effects of different doses of exercise on pancreatic ß-cell function in patients with newly diagnosed type 2 diabetes: study protocol for and rationale behind the "DOSE-EX" multi-arm parallel-group randomised clinical trial.

BACKGROUND: Lifestyle intervention, i.e. diet and physical activity, forms the basis for care of type 2 diabetes (T2D). The current physical activity recommendation for T2D is aerobic training for 150 min/week of moderate to vigorous intensity, supplemented with resistance training 2-3 days/week, with no more than two consecutive days without physical activity. The rationale for the recommendations is based on studies showing a reduction in glycated haemoglobin (HbA1c). This reduction is supposed to be caused by increased insulin sensitivity in muscle and adipose tissue, whereas knowledge about effects on abnormalities in the liver and pancreas are scarce, with the majority of evidence stemming from in vitro and animal studies. The aim of this study is to investigate the role of the volume of exercise training as an adjunct to dietary therapy in order to improve the pancreatic ß-cell function in T2D patients less than 7 years from diagnosis. The objective of this protocol for the DOSE-EX trial is to describe the scientific rationale in detail and to provide explicit information about study procedures and planned analyses. METHODS/DESIGN: In a parallel-group, 4-arm assessor-blinded randomised clinical trial, 80 patients with T2D will be randomly allocated (1:1:1:1, stratified by sex) to 16 weeks in either of the following groups: (1) no intervention (CON), (2) dietary intervention (DCON), (3) dietary intervention and supervised moderate volume exercise (MED), or (4) dietary intervention and supervised high volume exercise (HED). Enrolment was initiated December 15th, 2018, and will continue until N = 80 or December 1st, 2021. Primary outcome is pancreatic beta-cell function assessed as change in late-phase disposition index (DI) from baseline to follow-up assessed by hyperglycaemic clamp. Secondary outcomes include measures of cardiometabolic risk factors and the effect on subsequent complications related to T2D. The study was approved by The Scientific Ethical Committee at the Capital Region of Denmark (H-18038298). TRIAL REGISTRATION: The Effects of Different Doses of Exercise on Pancreatic ß-cell Function in Patients With Newly Diagnosed Type 2 Diabetes (DOSE-EX), NCT03769883, registered 10 December 2018 https://clinicaltrials.gov/ct2/show/NCT03769883 ). Any modification to the protocol, study design, and changes in written participant information will be approved by The Scientific Ethical Committee at the Capital Region of Denmark before effectuation. DISCUSSION: The data from this study will add knowledge to which volume of exercise training in combination with a dietary intervention is needed to improve ß-cell function in T2D. Secondarily, our results will elucidate mechanisms of physical activity mitigating the development of micro- and macrovascular complications correlated with T2D.

Can Computed Tomography Perfusion Predict Treatment Response After Prostate Artery Embolization: A Feasibility Study.

Prostate artery embolization (PAE) is an emerging therapy for benign prostatic hyperplasia (BPH). Optimal patient selection is an important step when introducing new treatments and several characteristics associated with a good clinical outcome has previously been proposed. However, no prognostic tool is yet available for PAE. Computed tomography perfusion is an imaging technique that provides hemodynamic parameters making it possible to estimate the prostatic blood flow (PBF). This study investigated the relationship between PBF and the response to PAE. A post hoc analysis including prostate-specific antigen (PSA) measurements before and 24-h after embolization from two prospective studies on sixteen patients undergoing PAE with BPH or prostate cancer were performed. The primary outcome was the correlation between baseline PBF and the change in PSA as a surrogate measure of treatment response. Prostate volume strongly correlated with treatment response and the response was greater with incremental amounts of injected embolic material. PBF was not associated with elevation in PSA and added no information that could guide patient selection.

Automatic Pulmonary Nodule Detection Applying Deep Learning or Machine Learning Algorithms to the LIDC-IDRI Database: A Systematic Review.

The aim of this study was to provide an overview of the literature available on machine learning (ML) algorithms applied to the Lung Image Database Consortium Image Collection (LIDC-IDRI) database as a tool for the optimization of detecting lung nodules in thoracic CT scans. This systematic review was compiled according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only original research articles concerning algorithms applied to the LIDC-IDRI database were included. The initial search yielded 1972 publications after removing duplicates, and 41 of these articles were included in this study. The articles were divided into two subcategories describing their overall architecture. The majority of feature-based algorithms achieved an accuracy >90% compared to the deep learning (DL) algorithms that achieved an accuracy in the range of 82.2%⁻97.6%. In conclusion, ML and DL algorithms are able to detect lung nodules with a high level of accuracy, sensitivity, and specificity using ML, when applied to an annotated archive of CT scans of the lung. However, there is no consensus on the method applied to determine the efficiency of ML algorithms.

The Performance of Deep Learning Algorithms on Automatic Pulmonary Nodule Detection and Classification Tested on Different Datasets That Are Not Derived from LIDC-IDRI: A Systematic Review.

The aim of this study was to systematically review the performance of deep learning technology in detecting and classifying pulmonary nodules on computed tomography (CT) scans that were not from the Lung Image Database Consortium and Image Database Resource Initiative (LIDC-IDRI) database. Furthermore, we explored the difference in performance when the deep learning technology was applied to test datasets different from the training datasets. Only peer-reviewed, original research articles utilizing deep learning technology were included in this study, and only results from testing on datasets other than the LIDC-IDRI were included. We searched a total of six databases: EMBASE, PubMed, Cochrane Library, the Institute of Electrical and Electronics Engineers, Inc. (IEEE), Scopus, and Web of Science. This resulted in 1782 studies after duplicates were removed, and a total of 26 studies were included in this systematic review. Three studies explored the performance of pulmonary nodule detection only, 16 studies explored the performance of pulmonary nodule classification only, and 7 studies had reports of both pulmonary nodule detection and classification. Three different deep learning architectures were mentioned amongst the included studies: convolutional neural network (CNN), massive training artificial neural network (MTANN), and deep stacked denoising autoencoder extreme learning machine (SDAE-ELM). The studies reached a classification accuracy between 68-99.6% and a detection accuracy between 80.6-94%. Performance of deep learning technology in studies using different test and training datasets was comparable to studies using same type of test and training datasets. In conclusion, deep learning was able to achieve high levels of accuracy, sensitivity, and/or specificity in detecting and/or classifying nodules when applied to pulmonary CT scans not from the LIDC-IDRI database.

Assessing Tumor Response to Treatment in Patients with Lung Cancer Using Dynamic Contrast-Enhanced CT.

The aim of this study was to provide an overview of the literature available on dynamic contrast-enhanced computed tomography (DCE-CT) as a tool to evaluate treatment response in patients with lung cancer. This systematic review was compiled according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only original research articles concerning treatment response in patients with lung cancer assessed with DCE-CT were included. To assess the validity of each study we implemented Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). The initial search yielded 651 publications, and 16 articles were included in this study. The articles were divided into groups of treatment. In studies where patients were treated with systemic chemotherapy with or without anti-angiogenic drugs, four out of the seven studies found a significant decrease in permeability after treatment. Four out of five studies that measured blood flow post anti-angiogenic treatments found that blood flow was significantly decreased. DCE-CT may be a useful tool in assessing treatment response in patients with lung cancer. It seems that particularly permeability and blood flow are important perfusion values for predicting treatment outcome. However, the heterogeneity in scan protocols, scan parameters, and time between scans makes it difficult to compare the included studies.

Interobserver and Intraobserver Reproducibility with Volume Dynamic Contrast Enhanced Computed Tomography (DCE-CT) in Gastroesophageal Junction Cancer.

The purpose of this study was to assess inter- and intra-observer reproducibility of three different analytic methods to evaluate quantitative dynamic contrast-enhanced computed tomography (DCE-CT) measures from gastroesophageal junctional cancer. Twenty-five DCE-CT studies with gastroesophageal junction cancer were selected from a previous longitudinal study. Three radiologists independently reviewed all scans, and one repeated the analysis eight months later for intraobserver analysis. Review of the scans consisted of three analysis methods: (I) Four, fixed small sized regions of interest (2-dimensional (2D) fixed ROIs) placed in the tumor periphery, (II) 2-dimensional regions of interest (2D-ROI) along the tumor border in the tumor center, and (III) 3-dimensional volumes of interest (3D-VOI) containing the entire tumor volume. Arterial flow, blood volume and permeability (k(trans)) were recorded for each observation. Inter- and intra-observer variability were assessed by Intraclass Correlation Coefficient (ICC) and Bland-Altman statistics. Interobserver ICC was excellent for arterial flow (0.88), for blood volume (0.89) and for permeability (0.91) with 3D-VOI analysis. The 95% limits of agreement were narrower for 3D analysis compared to 2D analysis. Three-dimensional volume DCE-CT analysis of gastroesophageal junction cancer provides higher inter- and intra-observer reproducibility with narrower limits of agreement between readers compared to 2D analysis.

Dynamic Contrast-Enhanced CT in Patients with Pancreatic Cancer.

The aim of this systematic review is to provide an overview of the use of Dynamic Contrast-enhanced Computed Tomography (DCE-CT) in patients with pancreatic cancer. This study was composed according to the PRISMA guidelines 2009. The literature search was conducted in PubMed, Cochrane Library, EMBASE, and Web of Science databases to identify all relevant publications. The QUADAS-2 tool was implemented to assess the risk of bias and applicability concerns of each included study. The initial literature search yielded 483 publications. Thirteen articles were included. Articles were categorized into three groups: nine articles concerning primary diagnosis or staging, one article about tumor response to treatment, and three articles regarding scan techniques. In exocrine pancreatic tumors, measurements of blood flow in eight studies and blood volume in seven studies were significantly lower in tumor tissue, compared with measurements in pancreatic tissue outside of tumor, or normal pancreatic tissue in control groups of healthy volunteers. The studies were heterogeneous in the number of patients enrolled and scan protocols. Perfusion parameters measured and analyzed by DCE-CT might be useful in the investigation of characteristic vascular patterns of exocrine pancreatic tumors. Further clinical studies are desired for investigating the potential of DCE-CT in pancreatic tumors.

Computed tomography (CT) perfusion as an early predictive marker for treatment response to neoadjuvant chemotherapy in gastroesophageal junction cancer and gastric cancer--a prospective study.

OBJECTIVES: To evaluate whether early reductions in CT perfusion parameters predict response to pre-operative chemotherapy prior to surgery for gastroesophageal junction (GEJ) and gastric cancer. MATERIALS AND METHODS: Twenty-eight patients with adenocarcinoma of the gastro-esophageal junction (GEJ) and stomach were included. Patients received three series of chemotherapy before surgery, each consisting of a 3-week cycle of intravenous epirubicin, cisplatin or oxaliplatin, concomitant with capecitabine peroral. The patients were evaluated with a CT perfusion scan prior to, after the first series of, and after three series of chemotherapy. The CT perfusion scans were performed using a 320-detector row scanner. Tumour volume and perfusion parameters (arterial flow, blood volume and permeability) were computed on a dedicated workstation with a consensus between two radiologists. Response to chemotherapy was evaluated by two measures. Clinical response was defined as a tumour size reduction of more than 50%. Histological response was evaluated based on residual tumour cells in the surgical specimen using the standardized Mandard Score 1 to 5, in which values of 1 and 2 were classified as responders, and 3 to 5 were classified as nonresponders. RESULTS: A decrease in tumour permeability after one series of chemotherapy was positively correlated with clinical response after three series of chemotherapy. Significant changes in permeability and tumour volume were apparent after three series of chemotherapy in both clinical and histological responders. A cut-off value of more than 25% reduction in tumour permeability yielded a sensitivity of 69% and a specificity of 58% for predicting clinical response. CONCLUSION: Early decrease in permeability is correlated with the likelihood of clinical response to pre-operative chemotherapy in GEJ and gastric cancer. As a single diagnostic test, CT Perfusion only has moderate sensitivity and specificity in response assessment of pre-operative chemotherapy making it insufficient for clinical decision purposes.

Comparison of the diagnostic performance of CT colonography interpreted by radiologists and radiographers.

OBJECTIVE: To compare computed tomographic colonography (CTC) performance of four trained radiographers with the CTC performance of two experienced radiologists. METHODS: Four radiographers and two radiologists interpreted 87 cases with 40 polyps ≥6 mm. Sensitivity, specificity, and positive predictive value (PPV) were assessed on a per-patient basis. On a per-polyp basis, sensitivity was calculated according to the respective size categories (polyps ≥6 mm as well as polyps ≥10 mm). RESULTS: Overall per-patient sensitivity for polyps ≥6 mm was 76.2 % (95 % CI 61.4-91.0) and 76.2 % (95 % CI 61.7-90.6), for the radiographers and radiologists, respectively. Overall per-patient specificity for polyps ≥6 mm were 81.4 % (95 % CI 73.7-89.2) and 81.1 % (95 % CI 73.8-88.3) for the radiographers and the radiologists, respectively. For the radiographers, overall per-polyp sensitivity was 60.3 % (95 % CI 50.3-70.3) and 60.7 % (95 % CI 42.2-79.2) for polyps ≥6 mm and ≥10 mm, respectively. For the radiologists, overall per polyp sensitivity was 59.2 % (95 % CI 46.4-72.0) and 69.0 % (95 % CI 48.1-89.6) for polyps ≥6 mm and ≥10 mm, respectively. CONCLUSION: Radiographers with training in CT colonographic evaluation achieved sensitivity and specificity in polyp detection comparable with that of experienced radiologists. MAIN MESSAGES: • The diagnostic accuracy of trained radiographers was comparable to that of experienced radiologists. • The use of radiographers in reading CTC examinations is acceptable, however radiologists would still be necessary for the evaluation of extracolonic findings. • Skilled non-radiologists may play a vital role as a second reader of intraluminal findings or by performing quality control of examinations before patient dismissal.

Computed Tomography (CT) Perfusion in Abdominal Cancer: Technical Aspects.

Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed table position. Advances in reconstruction algorithms make it possible to reduce the radiation dose for each examination to acceptable levels. Regarding abdominal imaging, CT perfusion is still considered a research tool, but several studies have proven it as a reliable non-invasive technique for assessment of vascularity. CT perfusion has also been used for tumor characterization, staging of disease, response evaluation of newer drugs targeted towards angiogenesis and as a method for early detection of recurrence after radiation and embolization. There are several software solutions available on the market today based on different perfusion algorithms. However, there is no consensus on which protocol and algorithm to use for specific organs. In this article, the authors give an introduction to CT perfusion in abdominal imaging introducing technical aspects for calculation of perfusion parameters, and considerations on patient preparation. This article also contains clinical cases to illustrate the use of CT perfusion in abdominal imaging.

Effect of a tele-training programme on radiographers in the interpretation of CT colonography.

OBJECTIVE: To assess the performance of radiographers in CT colonography (CTC) after a tele-training programme, supervised by 2 experienced radiologists. MATERIALS AND METHODS: Five radiographers underwent training in CTC using a tele-training programme mainly based on the interpretation of 75 training cases performed in the novice department. To evaluate the educational performance, each radiographer was tested on 20 test cases with 27 lesions >6mm (12: 6-9 mm; 15: >10mm). Sensitivity, specificity and PPV for polyps ≥ 6 mm and ≥ 10 mm were calculated with point estimates and 95% confidence interval (95% CI). The results were compared by comparing 95% CI with a 5% significance level. RESULTS: In the training cases overall per-polyp sensitivity was 57% (95% CI 46.1-67.9) and 69.1% (95% CI 50.6-87.5) for lesions ≥ 6 mm and ≥ 10 mm, respectively. Overall per patient sensitivity, specificity and PPV were 86.4% (95% CI 76.7-96.1), 85.4% (95% CI 77-93.9) and 78.3% (95% CI 64.9-91.7), respectively. In the test cases overall per-polyp sensitivity was 80.7% (95% CI 69.5-92) and 94.7% (95% CI 85.6-100 ×) for lesions ≥ 6 mm and ≥ 10 mm, respectively. Overall per patient sensitivity, specificity and PPV were 92.9% (95% CI 83.1-100 ×), 64% (95% CI 13.1-100 ×) and 87.8% (95% CI 71.7-100 ×), respectively. There was a statistically significant improvement in per-polyp sensitivity for lesions ≥ 6 mm in the test cases. No statistically significant differences were found in per patient sensitivity, specificity and PPV, but there was an improvement. CONCLUSION: This training programme based on tele-training obtained good performance of radiographers in detecting tumoral lesions in CTC.