ESR Essentials: Imaging in colorectal cancer-practice recommendations by ESGAR.

Colorectal cancer (CRC) is a significant global health concern. Diagnostic imaging, using different modalities, has a pivotal role in CRC, from early detection (i.e., screening) to follow-up. The role of imaging in CRC screening depends on each country's approach: if an organized screening program is in place, the role of CT colonography (CTC) is limited to the study of either individuals with a positive stool test unwilling/unable to undergo colonoscopy (CC) or in patients with incomplete CC. Although CC is the most common modality to diagnose CRC, CRC can be also incidentally detected during a routine abdominal imaging examination or at the emergency room in patients presenting with intestinal occlusion/subocclusion or perforation. Staging is a crucial aspect of CRC management, guiding treatment decisions and providing valuable prognostic information. An accurate local staging is mandatory in both rectal and colon cancer to drive the appropriate therapeutic workflow. Important limitations of US, CT, and MR in N-staging can be partially solved by FDG PET/CT. Distant staging is usually managed by CT, with MR and FDG PET/CT which can be used as problem-solving techniques. Follow-up is performed according to the general recommendations of the oncological societies. CLINICAL RELEVANCE STATEMENT: It is essential to summarize each phase of colorectal cancer workup, differentiating the management for colon and rectal cancer supported by the main international guidelines and literature data, with the aim to inform the community on the best practice imaging in colorectal cancer. KEY POINTS: • Colorectal cancer is a prevalent disease that lends itself to imaging at each stage of detection and management. • Various imaging modalities can be used as adjuncts to, or in place of, direct visualization methods of screening and are necessary for evaluating metastatic disease. • Reevaluation of follow-up strategies should be considered depending on patients' individual risk of recurrence.

CT colonography: can we achieve an adequate bowel preparation without diet restriction?

OBJECTIVE: To evaluate if an adequate bowel preparation for CT colonography, can be achieved without diet restriction, using a reduced amount of cathartic agent and fecal tagging. To investigate the influence of patients' characteristics on bowel preparation and the impact on patients' compliance. METHODS: In total, 1446 outpatients scheduled for elective CT colonography were prospectively enrolled. All patients had the same bowel preparation based on a reduced amount of cathartic agent (120 g of macrogol in 1.5 l of water) the day before the exam and a fecal tagging agent (60 ml of hyperosmolar oral iodinated agent) the day of the exam. No dietary restrictions were imposed before the exam. The bowel preparation was evaluated using a qualitative and quantitative score. Patients were grouped by age, gender, and presence of diverticula in both scores. Patients' compliance has been evaluated with a questionnaire after the end of the exam and with a phone-calling interview the day after the exam. RESULTS: According to the qualitative score, adequate bowel preparation was achieved in 1349 patients (93.29%) and no statistical differences were observed among the subgroups of patients. Quantitative scores demonstrated that colon distension was significantly better in younger patients and without diverticula. A good patients' compliance was observed and most patients (96.5%) were willing to repeat it. CONCLUSIONS: The lack of diet restriction does not affect the quality of CTC preparation and good patient's compliance could potentially increase the participation rate in CRC screening programs. KEY POINTS: • An adequate quality bowel preparation for CT colonography can be achieved without diet restriction, using a reduced amount of cathartic agent (120 g of macrogol in 1.5 l of water) and fecal tagging (60 ml of hyperosmolar oral iodinated agent). • A bowel preparation based on the combination of a reduced amount of cathartic agent and fecal tagging, without diet restriction, allows obtaining good quality in more than 90% of patients. • The bowel preparation scheme proposed reduces the distress and discomfort experienced by the patients improving adherence to CTC.

Peri-gastric appendagitis with lesser omentum hemorrhagic infarction: US, CT, and MRI findings of a rare entity.

Peri-gastric appendagitis followed associated with gastro-hepatic ligament/lesser omentum hemorrhagic infarction has not been well investigated yet. With an accurate radiological diagnosis of peri-gastric appendagitis, even in case of hemorrhagic infarction, the patient can receive supportive measures for the self-limited pain and can forgo surgery, endoscopy, and further invasive testing.

Cell Adhesion and Initial Bone Matrix Deposition on Titanium-Based Implants with Chitosan-Collagen Coatings: An In Vitro Study.

In orthopedics, titanium (Ti)-alloy implants, are often considered as the first-choice candidates for bone tissue engineering. An appropriate implant coating enhances bone matrix ingrowth and biocompatibility, improving osseointegration. Collagen I (COLL) and chitosan (CS) are largely employed in several different medical applications, for their antibacterial and osteogenic properties. This is the first in vitro study that provides a preliminary comparison between two combinations of COLL/CS coverings for Ti-alloy implants, in terms of cell adhesion, viability, and bone matrix production for probable future use as a bone implant. Through an innovative spraying technique, COLL-CS-COLL and CS-COLL-CS coverings were applied over Ti-alloy (Ti-POR) cylinders. After cytotoxicity evaluations, human bone marrow mesenchymal stem cells (hBMSCs) were seeded onto specimens for 28 days. Cell viability, gene expression, histology, and scanning electron microscopy evaluations were performed. No cytotoxic effects were observed. All cylinders were biocompatible, thus permitting hBMSCs' proliferation. Furthermore, an initial bone matrix deposition was observed, especially in the presence of the two coatings. Neither of the coatings used interferes with the osteogenic differentiation process of hBMSCs, or with an initial deposition of new bone matrix. This study sets the stage for future, more complex, ex vivo or in vivo studies.

A Focus on the Synergy of Radiomics and RNA Sequencing in Breast Cancer.

Radiological imaging is currently employed as the most effective technique for screening, diagnosis, and follow up of patients with breast cancer (BC), the most common type of tumor in women worldwide. However, the introduction of the omics sciences such as metabolomics, proteomics, and molecular genomics, have optimized the therapeutic path for patients and implementing novel information parallel to the mutational asset targetable by specific clinical treatments. Parallel to the "omics" clusters, radiological imaging has been gradually employed to generate a specific omics cluster termed "radiomics". Radiomics is a novel advanced approach to imaging, extracting quantitative, and ideally, reproducible data from radiological images using sophisticated mathematical analysis, including disease-specific patterns, that could not be detected by the human eye. Along with radiomics, radiogenomics, defined as the integration of "radiology" and "genomics", is an emerging field exploring the relationship between specific features extracted from radiological images and genetic or molecular traits of a particular disease to construct adequate predictive models. Accordingly, radiological characteristics of the tissue are supposed to mimic a defined genotype and phenotype and to better explore the heterogeneity and the dynamic evolution of the tumor over the time. Despite such improvements, we are still far from achieving approved and standardized protocols in clinical practice. Nevertheless, what can we learn by this emerging multidisciplinary clinical approach? This minireview provides a focused overview on the significance of radiomics integrated by RNA sequencing in BC. We will also discuss advances and future challenges of such radiomics-based approach.

Pneumonia Frequency and Severity in Patients With Symptomatic COVID-19: Impact of mRNA and Adenovirus Vector Vaccines.

BACKGROUND. Additional evidence of the role of COVID-19 vaccination in reducing pneumonia frequency and severity in the setting of breakthrough infection could help combat ongoing vaccine hesitancy. OBJECTIVE. The purpose of this article was to compare the frequency and severity of pneumonia on chest CT in patients with confirmed COVID-19 between patients who are unvaccinated and those who are fully vaccinated by messenger RNA (mRNA) or adenovirus vector vaccines. METHODS. This retrospective single-center study included 467 patients (250 men, 217 women; mean age, 65 ± 17 [SD] years) who underwent chest CT between December 15, 2021, and February 18, 2022, during hospitalization for symptomatic COVID-19, confirmed by reverse transcriptase-polymerase chain reaction assay. A total of 216 patients were unvaccinated, and 167 and 84 patients were fully vaccinated (defined as receipt of the second dose at least 14 days before COVID-19 diagnosis) by the BNT162b2 mRNA vaccine or the ChAdOx1-S adenovirus vector vaccine, respectively. Semiquantitative CT severity scores (CT-SS; 0-25 scale) were determined; CT-SS of 0 indicated absence of pneumonia. Presence of bilateral involvement was assessed in patients with pneumonia. Associations were explored between vaccination status and CT findings. RESULTS. The frequency of the absence of pneumonia was 15% (32/216) in unvaccinated patients, 29% (24/84) in patients fully vaccinated with ChAdOx1-S vaccine, and 51% (85/167) in patients fully vaccinated with BNT162b2 vaccine (unvaccinated and ChAdOx1-S vs BNT162b2: p < .001; unvaccinated vs ChAdOx1-S: p = .08). Mean CT-SS was significantly higher in unvaccinated patients (9.7 ± 6.1) than in patients fully vaccinated with BNT162b2 (5.2 ± 6.1) or ChAdOx1-S (6.2 ± 5.9) vaccine (both p < .001). Full vaccination was significantly associated with CT-SS independent of patient age and sex (estimate = -4.46; p < .001). Frequency of bilateral lung involvement was significantly higher in unvaccinated patients (158/184, 86%) and in patients fully vaccinated with ChAdOx1-S vaccine (54/60, 90%) than in patients fully vaccinated with BNT162b2 vaccine (47/82, 57%) (both p < .001). CONCLUSION. Pneumonia frequency and severity were lower in patients with full vaccination by mRNA and adenovirus vector vaccines who experienced breakthrough infections in comparison with unvaccinated patients. CLINICAL IMPACT. The visual observation by radiologic imaging of the protective effect of vaccination on lung injury in patients with breakthrough infections provides additional evidence supporting the clinical benefit of vaccination.

A narrative review on current imaging applications of artificial intelligence and radiomics in oncology: focus on the three most common cancers.

The use of artificial intelligence (AI) and radiomics in the healthcare setting to advance disease diagnosis and management and facilitate the creation of new therapeutics is gaining popularity. Given the vast amount of data collected during cancer therapy, there is significant concern in leveraging the algorithms and technologies available with the underlying goal of improving oncologic care. Radiologists will attain better precision and effectiveness with the advent of AI technology, making machine-assisted medical services a valuable and important option for future oncologic medical care. As a result, it is critical to figure out which specific radiology activities are best positioned to gain from AI and radiomics models and methods of oncologic imaging, while also considering the algorithms' capabilities and constraints. Our purpose is to overview the current evidence and future prospects of AI and radiomics algorithms used in oncologic imaging efforts with an emphasis on the three most frequent cancers worldwide, i.e., lung cancer, breast cancer and colorectal cancer. We discuss how AI and radiomics could be used to detect and characterize cancers and assess therapy response.

Diagnostic accuracy and interobserver variability of CO-RADS in patients with suspected coronavirus disease-2019: a multireader validation study.

OBJECTIVE: To conduct a multireader validation study to evaluate the interobserver variability and the diagnostic accuracy for the lung involvement by COVID-19 of COVID-19 Reporting and Data System (CO-RADS) score. METHODS: This retrospective study included consecutive symptomatic patients who underwent chest CT and reverse transcriptase-polymerase chain reaction (RT-PCR) from March 2020 to May 2020 for suspected COVID-19. Twelve readers with different levels of expertise independently scored each CT using the CO-RADS scheme for detecting pulmonary involvement by COVID-19. Receiver operating characteristic (ROC) curves were computed to investigate diagnostic yield. Fleiss' kappa statistics was used to evaluate interreader agreement. RESULTS: A total of 572 patients (mean age, 63 ± 20 [standard deviation]; 329 men; 142 patients with COVID-19 and 430 patients without COVID-19) were evaluated. There was a moderate agreement for CO-RADS rating among all readers (Fleiss' K = 0.43 [95% CI 0.42-0.44]) with a substantial agreement for CO-RADS 1 category (Fleiss' K = 0.61 [95% CI 0.60-0.62]) and moderate agreement for CO-RADS 5 category (Fleiss' K = 0.60 [95% CI 0.58-0.61]). ROC analysis showed the CO-RADS score ≥ 4 as the optimal threshold, with a cumulative area under the curve of 0.72 (95% CI 66-78%), sensitivity 61% (95% CI 52-69%), and specificity 81% (95% CI 77-84%). CONCLUSION: CO-RADS showed high diagnostic accuracy and moderate interrater agreement across readers with different levels of expertise. Specificity is higher than previously thought and that could lead to reconsider the role of CT in this clinical setting. KEY POINTS: • COVID-19 Reporting and Data System (CO-RADS) demonstrated a good diagnostic accuracy for lung involvement by COVID-19 with an average AUC of 0.72 (95% CI 67-75%). • When a threshold of ≥ 4 was used, sensitivity and specificity were 61% (95% CI 52-69%) and 81% (95% CI 76-84%), respectively. • There was an overall moderate agreement for CO-RADS rating across readers with different levels of expertise (Fleiss' K = 0.43 [95% CI 0.42-0.44]).

Imaging alternatives to colonoscopy: CT colonography and colon capsule. European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline - Update 2020.

MAIN RECOMMENDATIONS: 1. ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia. Strong recommendation, high quality evidence. ESGE/ESGAR do not recommend barium enema in this setting. Strong recommendation, high quality evidence.2. ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. The timing depends on an interdisciplinary decision including endoscopic and radiological factors. Strong recommendation, low quality evidence. ESGE/ESGAR suggests that, in centers with expertise in and availability of colon capsule endoscopy (CCE), CCE preferably the same or the next day may be considered if colonoscopy is incomplete. Weak recommendation, low quality evidence.3. When colonoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with alarm symptoms. Strong recommendation, high quality evidence. Because of lack of direct evidence, ESGE/ESGAR do not recommend CCE in this situation. Very low quality evidence. ESGE/ESGAR recommend CTC as an acceptable alternative to colonoscopy for patients with non-alarm symptoms. Strong recommendation, high quality evidence. In centers with availability, ESGE/ESGAR suggests that CCE may be considered in patients with non-alarm symptoms. Weak recommendation, low quality evidence.4. Where there is no organized fecal immunochemical test (FIT)-based population colorectal screening program, ESGE/ESGAR recommend CTC as an option for colorectal cancer screening, providing the screenee is adequately informed about test characteristics, benefits, and risks, and depending on local service- and patient-related factors. Strong recommendation, high quality evidence. ESGE/ESGAR do not suggest CCE as a first-line screening test for colorectal cancer. Weak recommendation, low quality evidence.5. ESGE/ESGAR recommend CTC in the case of a positive fecal occult blood test (FOBT) or FIT with incomplete or unfeasible colonoscopy, within organized population screening programs. Strong recommendation, moderate quality evidence. ESGE/ESGAR also suggest the use of CCE in this setting based on availability. Weak recommendation, moderate quality evidence.6. ESGE/ESGAR suggest CTC with intravenous contrast medium injection for surveillance after curative-intent resection of colorectal cancer only in patients in whom colonoscopy is contraindicated or unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in this setting. Very low quality evidence.7. ESGE/ESGAR suggest CTC in patients with high risk polyps undergoing surveillance after polypectomy only when colonoscopy is unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in post-polypectomy surveillance. Very low quality evidence.8. ESGE/ESGAR recommend against CTC in patients with acute colonic inflammation and in those who have recently undergone colorectal surgery, pending a multidisciplinary evaluation. Strong recommendation, low quality evidence.9. ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp ≥6 mm detected at CTC or CCE. Follow-up CTC may be clinically considered for 6-9-mm CTC-detected lesions if patients do not undergo polypectomy because of patient choice, comorbidity, and/or low risk profile for advanced neoplasia. Strong recommendation, moderate quality evidence. Source and scope This is an update of the 2014-15 Guideline of the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR). It addresses the clinical indications for the use of imaging alternatives to standard colonoscopy. A targeted literature search was performed to evaluate the evidence supporting the use of computed tomographic colonography (CTC) or colon capsule endoscopy (CCE). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence.

Preoperative measurement of the hiatal surface with MDCT: impact on surgical planning.

OBJECTIVE: To evaluate the accuracy and reproducibility of hiatal surface area (HSA) measurement on dedicated multidetector computed tomography (MDCT) acquisition, in patients, previously subjected to laparoscopic sleeve gastrectomy (LSG), and affected by gastroesophageal reflux disease (GERD). Intraoperative HSA measurement was considered the reference standard. METHODS: Fifty-two candidates for laparoscopic hiatal hernia repair were prospectively included in the study. MDCT images were acquired during swallowing of oral iodinated contrast media and during strain. Measurements were performed by nine readers divided into three groups according to their experience. Results were compared with intraoperative measurements by means of Spearman correlation coefficient. Reproducibility was evaluated with intra- and interreader agreement by means of weighted Cohen's kappa and intraclass correlation coefficient (ICC). RESULTS: Significant differences between MDCT and intraoperative HSA measurements were observed for swallowing imaging for less experienced readers (p = 0.037, 0.025, 0.028 and 0.019). No other statistically significant differences were observed (p > 0.05). The correlation between HSA measured intraoperatively and on MDCT was higher for strain imaging compared to swallowing (r = 0.94-0.92 vs 0.94-0.89). The overall reproducibility of MDCT HSA measurement was excellent (ICC of 0.95; 95% CI 0,8993 to 0,9840) independently of reader's experience CONCLUSION: HSA can be accurately measured on MDCT images. This method is reproducible and minimally influenced by reader experience. The preoperative measurement of HSA has potential advantages for surgeons in terms of correct approach to hiatal defects in obese patient.

Imaging alternatives to colonoscopy: CT colonography and colon capsule. European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline - Update 2020.

1: ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia.Strong recommendation, high quality evidence.ESGE/ESGAR do not recommend barium enema in this setting.Strong recommendation, high quality evidence. 2: ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. The timing depends on an interdisciplinary decision including endoscopic and radiological factors.Strong recommendation, low quality evidence.ESGE/ESGAR suggests that, in centers with expertise in and availability of colon capsule endoscopy (CCE), CCE preferably the same or the next day may be considered if colonoscopy is incomplete.Weak recommendation, low quality evidence. 3: When colonoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with alarm symptoms.Strong recommendation, high quality evidence.Because of lack of direct evidence, ESGE/ESGAR do not recommend CCE in this situation.Very low quality evidence.ESGE/ESGAR recommend CTC as an acceptable alternative to colonoscopy for patients with non-alarm symptoms.Strong recommendation, high quality evidence.In centers with availability, ESGE/ESGAR suggests that CCE may be considered in patients with non-alarm symptoms.Weak recommendation, low quality evidence. 4: Where there is no organized fecal immunochemical test (FIT)-based population colorectal screening program, ESGE/ESGAR recommend CTC as an option for colorectal cancer screening, providing the screenee is adequately informed about test characteristics, benefits, and risks, and depending on local service- and patient-related factors.Strong recommendation, high quality evidence.ESGE/ESGAR do not suggest CCE as a first-line screening test for colorectal cancer.Weak recommendation, low quality evidence. 5: ESGE/ESGAR recommend CTC in the case of a positive fecal occult blood test (FOBT) or FIT with incomplete or unfeasible colonoscopy, within organized population screening programs.Strong recommendation, moderate quality evidence.ESGE/ESGAR also suggest the use of CCE in this setting based on availability.Weak recommendation, moderate quality evidence. 6: ESGE/ESGAR suggest CTC with intravenous contrast medium injection for surveillance after curative-intent resection of colorectal cancer only in patients in whom colonoscopy is contraindicated or unfeasibleWeak recommendation, low quality evidence.There is insufficient evidence to recommend CCE in this setting.Very low quality evidence. 7: ESGE/ESGAR suggest CTC in patients with high risk polyps undergoing surveillance after polypectomy only when colonoscopy is unfeasible.Weak recommendation, low quality evidence.There is insufficient evidence to recommend CCE in post-polypectomy surveillance.Very low quality evidence. 8: ESGE/ESGAR recommend against CTC in patients with acute colonic inflammation and in those who have recently undergone colorectal surgery, pending a multidisciplinary evaluation.Strong recommendation, low quality evidence. 9: ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp ≥ 6 mm detected at CTC or CCE.Follow-up CTC may be clinically considered for 6 - 9-mm CTC-detected lesions if patients do not undergo polypectomy because of patient choice, comorbidity, and/or low risk profile for advanced neoplasia.Strong recommendation, moderate quality evidence.

Hepatocellular carcinoma in adult thalassemia patients: an expert opinion based on current evidence.

Beta-thalassemia represents a heterogeneous group of haemoglobin inherited disorders, among the most common genetic diseases in the world, frequent in the Mediterranean basin. As beta-thalassemia patients' survival has increased over time, previously unknown complications are observed with increasing frequency. Among them, an increased risk of hepatocellular carcinoma (HCC) has been registered. Our aim is to reduce inequalities in diagnosis and treatment and to offer patients univocal recommendations in any institution.The members of the panel - gastroenterologists, radiologists, surgeons and oncologists -were selected on the basis of their publication records and expertise. Thirteen clinical questions, derived from clinical needs, and an integration of all the committee members' suggestions, were formulated. Modified Delphi approach involving a detailed literature review and the collective judgement of experts, was applied to this work.Thirteen statements were derived from expert opinions' based on the current literature, on recently developed reviews and on technological advancements. Each statement is discussed in a short paragraph reporting the current key evidence. As this is an emerging issue, the number of papers on HCC in beta-thalassemia patients is limited and based on anecdotal cases rather than on randomized controlled studies. Therefore, the panel has discussed, step by step, the possible differences between beta-thalassemia and non beta-thalassemia patients. Despite the paucity of the literature, practical and concise statements were generated.This paper offers a practical guide organized by statements describing how to manage HCC in patients with beta-thalassemia.

Diagnostic Yield of Computed Tomography for the Identification of Coronavirus Disease 2019 Using Repeated Reverse Transcriptase Polymerase Chain Reaction Testing or Confirmed True-Negative State as Reference Standard: Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of this study was to perform a meta-analysis assessing the diagnostic yield of computed tomography (CT) for the identification of coronavirus disease 2019 (COVID-19) using repeated reverse transcriptase polymerase chain reaction testing or confirmed true-negative state as reference standard. METHODS: In May 2020, we interrogated the MEDLINE, Embase, and CENTRAL databases. Pooled sensitivity, specificity, and diagnostic odds ratios of CT for COVID-19 identification were computed. Cumulative positive predictive value (PPV) and negative predictive value, stratified by disease prevalence, were calculated. RESULTS: Ten articles were included (1332 patients). Pooled sensitivity, specificity, and summary diagnostic odds ratio of CT were 82% [95% confidence interval (CI), 79%-84%], 68% (95% CI, 65%-71%), and 18 (95% CI, 9.8-32.8). The PPV and negative predictive value were 54% (95% CI, 30%-77%) and 94% (95% CI, 88%-99%) at a COVID-19 prevalence lower than 40%, and 80% (95% CI, 62%-91%) and 77% (95% CI, 68%-85%) at a prevalence higher than 40%. CONCLUSION: CT yields higher specificity and PPV, albeit lower sensitivity, than previously reported for the identification of COVID-19.

Myocarditis: imaging up to date.

Myocarditis is an inflammatory disease of the heart muscle, diagnosed by histological, immunological, and immunohistochemical criteria. Endomyocardial biopsy represents the diagnostic gold standard for its diagnosis but is infrequently used. Due to its noninvasive ability to detect the presence of myocardial edema, hyperemia and necrosis/fibrosis, Cardiac MR imaging is routinely used in the clinical practice for the diagnosis of acute myocarditis. Recently pixel-wise mapping of T1 and T2 relaxation time have been introduced into the clinical Cardiac MR protocol increasing its accuracy. Our paper will review the role of MR imaging in the diagnosis of acute myocarditis.

Systematic Review and Meta-Analysis Investigating the Diagnostic Yield of Dual-Energy CT for Renal Mass Assessment.

OBJECTIVE. The objective of our study was to perform a systematic review and meta-analysis to evaluate the diagnostic accuracy of dual-energy CT (DECT) for renal mass evaluation. MATERIALS AND METHODS. In March 2018, we searched MEDLINE, Cochrane Database of Systematic Reviews, Embase, and Web of Science databases. Analytic methods were based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Pooled estimates for sensitivity, specificity, and diagnostic odds ratios were calculated for DECT-based virtual monochromatic imaging (VMI) and iodine quantification techniques as well as for conventional attenuation measurements from renal mass CT protocols. I2 was used to evaluate heterogeneity. The methodologic quality of the included studies and potential bias were assessed using items from the Quality Assessment Tool for Diagnostic Accuracy Studies 2 (QUADAS-2). RESULTS. Of the 1043 articles initially identified, 13 were selected for inclusion (969 patients, 1193 renal masses). Cumulative data of sensitivity, specificity, and summary diagnostic odds ratio for VMI were 87% (95% CI, 80-92%; I2, 92.0%), 93% (95% CI, 90-96%; I2, 18.0%), and 183.4 (95% CI, 30.7-1093.4; I2, 61.6%), respectively. Cumulative data of sensitivity, specificity, and summary diagnostic odds ratio for iodine quantification were 99% (95% CI, 97-100%; I2, 17.6%), 91% (95% CI, 89-94%; I2, 84.2%), and 511.5 (95% CI, 217-1201; I2, 0%). No significant differences in AUCs were found when comparing iodine quantification to conventional attenuation measurements (p = 0.79). CONCLUSION. DECT yields high accuracy for renal mass evaluation. Determination of iodine content with the iodine quantification technique shows diagnostic accuracy similar to conventional attenuation measurements from renal mass CT protocols. The iodine quantification technique may be used to characterize incidental renal masses when a dedicated renal mass protocol is not available.

Patient centring and scan length: how inaccurate practice impacts on radiation dose in CT colonography (CTC).

OBJECTIVE: The aim of this study was to acknowledge errors in patients positioning in CT colonography (CTC) and their effect in radiation exposure. MATERIALS AND METHODS: CTC studies of a total of 199 patients coming from two different referral hospitals were retrospectively reviewed. Two parameters have been considered for the analysis: patient position in relation to gantry isocentre and scan length related to the area of interest. CTDI vol and DLP were extracted for each patient. In order to evaluate the estimated effective total dose and the dose to various organs, we used the CT-EXPO® software version 2.2. This software provides estimates of effective dose and doses to the other various organs. RESULTS: Average value of the patients' position is found to be below the isocentre for 48 ± 25 mm and 29 ± 27 mm in the prone and supine position. It was observed that the increase in CTDI and DLP values for patients in Group 1, due to the inaccurate positioning, was estimated at about 30% and 20% for prone and supine position, respectively, while in Group 2, a decrease in CTDI and DLP values was estimated at about 16% and 18% for prone and supine position, respectively, due to an average position above isocentre. A dose increase ranging from 4 up to 13% was calculated with increasing the over-scanned region below anal orifice. CONCLUSION: Radiographers and radiologists need to be aware of dose variation and noise effects on vertical positioning and over-scanning. More accurate training need to be achieved even so when examination protocol varies from general practice.

Bowel preparation in CT colonography: Is diet restriction necessary? A randomised trial (DIETSAN).

OBJECTIVES: To investigate whether diet restriction affects quality of colon cleansing and patient tolerance during reduced bowel preparation for CT colonography (CTC). METHODS: Asymptomatic and symptomatic patients were enrolled in this pragmatic, single-centre, randomised trial. All patients were randomly assigned (1:1 ratio, blocks of ten) to receive a reduced bowel preparation and faecal tagging with (Diet-Restriction-Group [DR]) or without (No-Diet-Restriction-Group [NDR]) dietary restriction. Five readers performed a blinded subjective image analysis, by means of 4-point Likert-scales from 0 (highest score) to 3 (worst score). Endpoints were the quality of large bowel cleansing and tolerance to the assigned bowel preparation regimen. The trial is registered at ClinicalTrial.gov (URomLSDBAL1). RESULTS: Ninety-five patients were randomly allocated to treatments (48 in NDR-group, 47 in DR-group). Both groups resulted in optimal colon cleansing. The mean residual stool (0.22, 95%CI 0.00-0.44) and fluid burden (0.39, 95%CI 0.25-0.53) scores for patients in DR-group were similar to those in patients in NDR-group (0.25, 95%CI 0.03-0.47 [p = 0.82] and 0.49, 95%CI 0.30-0.67 [p = 0.38], respectively). Tolerance was significantly better in NDR-group. CONCLUSION: A reduced bowel preparation in association with faecal tagging and without any dietary restriction demonstrated optimal colon cleansing effectiveness for CTC, providing better patient compliance compared with dietary restriction. KEY POINTS: • Dietary restriction in reduced bowel preparation regimen can be avoided. • The quality of colon cleansing is not affected by dietary restriction. • The quality of faecal tagging is not affected by dietary restriction. • Avoidance of dietary restriction improves patients' tolerance for CTC.

Dual-Source Single-Energy Multidetector CT Used to Obtain Multiple Radiation Exposure Levels within the Same Patient: Phantom Development and Clinical Validation.

Purpose To develop, in a phantom environment, a method to obtain multidetector computed tomographic (CT) data sets at multiple radiation exposure levels within the same patient and to validate its use for potential dose reduction by using different image reconstruction algorithms for the detection of liver metastases. Materials and Methods The American College of Radiology CT accreditation phantom was scanned by using a dual-source multidetector CT platform. By adjusting the radiation output of each tube, data sets at six radiation exposure levels (100%, 75%, 50%, 37.5%, 25%, and 12.5%) were reconstructed from two consecutive dual-source single-energy (DSSE) acquisitions, as well as a conventional single-source acquisition. A prospective, HIPAA-compliant, institutional review board-approved study was performed by using the same DSSE strategy in 19 patients who underwent multidetector CT of the liver for metastatic colorectal cancer. All images were reconstructed by using conventional weighted filtered back projection (FBP) and sinogram-affirmed iterative reconstruction with strength level of 3 (SAFIRE-3). Objective image quality metrics were compared in the phantom experiment by using multiple linear regression analysis. Generalized linear mixed-effects models were used to analyze image quality metrics and diagnostic performance for lesion detection by readers. Results The phantom experiment showed comparable image quality between DSSE and conventional single-source acquisition. In the patient study, the mean size-specific dose estimates for the six radiation exposure levels were 13.0, 9.8, 5.8, 4.4, 3.2, and 1.4 mGy. For each radiation exposure level, readers' perception of image quality and lesion conspicuity was consistently ranked superior with SAFIRE-3 when compared with FBP (P ≤ .05 for all comparisons). Reduction of up to 62.5% in radiation exposure by using SAFIRE-3 yielded similar reader rankings of image quality and lesion conspicuity when compared with routine-dose FBP. Conclusion A method was developed and validated to synthesize multidetector CT data sets at multiple radiation exposure levels within the same patient. This technique may provide a foundation for future clinical trials aimed at estimating potential radiation dose reduction by using iterative reconstructions. © RSNA, 2016 Online supplemental material is available for this article.

Characterization of Incidental Renal Mass With Dual-Energy CT: Diagnostic Accuracy of Effective Atomic Number Maps for Discriminating Nonenhancing Cysts From Enhancing Masses.

OBJECTIVE: The purpose of this study was to assess the diagnostic accuracy of effective atomic number maps reconstructed from dual-energy contrast-enhanced data for discriminating between nonenhancing renal cysts and enhancing masses. MATERIALS AND METHODS: Two hundred six patients (128 men, 78 women; mean age, 64 years) underwent a CT renal mass protocol (single-energy unenhanced and dual-energy contrast-enhanced nephrographic imaging) at two different hospitals. For each set of patients, two blinded, independent observers performed measurements on effective atomic number maps from contrast-enhanced dual-energy data. Renal mass assessment on unenhanced and nephrographic images, corroborated by imaging and medical records, was the reference standard. The diagnostic accuracy of effective atomic number maps was assessed with ROC analysis. RESULTS: Significant differences in mean effective atomic numbers (Zeff) were observed between nonenhancing and enhancing masses (set A, 8.19 vs 9.59 Zeff; set B, 8.05 vs 9.19 Zeff; sets combined, 8.13 vs 9.37 Zeff) (p < 0.0001). An effective atomic number value of 8.36 Zeff was the optimal threshold, rendering an AUC of 0.92 (95% CI, 0.89-0.94), sensitivity of 90.8% (158/174 [95% CI, 85.5-94.7%]), specificity of 85.2% (445/522 [95% CI, 81.9-88.2%]), and overall diagnostic accuracy of 86.6% (603/696 [95% CI, 83.9-89.1%]). CONCLUSION: Nonenhancing renal cysts, including hyperattenuating cysts, can be discriminated from enhancing masses on effective atomic number maps generated from dual-energy contrast-enhanced CT data. This technique may be of clinical usefulness when a CT protocol for comprehensive assessment of renal masses is not available.

Use of a Noise Optimized Monoenergetic Algorithm for Patient-Size Independent Selection of an Optimal Energy Level During Dual-Energy CT of the Pancreas.

PURPOSE: To investigate the impact of a second-generation noise-optimized monoenergetic algorithm on selection of the optimal energy level, image quality, and effect of patient body habitus for dual-energy multidetector computed tomography of the pancreas. MATERIALS AND METHODS: Fifty-nine patients (38 men, 21 women) underwent dual-energy multidetector computed tomography (80/Sn140 kV) in the pancreatic parenchymal phase. Image data sets, at energy levels ranging from 40 to 80 keV (in 5-keV increments), were reconstructed using first-generation and second-generation noise-optimized monoenergetic algorithm. Noise, pancreatic contrast-to-noise ratio (CNRpancreas), and CNR with a noise constraint (CNRNC) were calculated and compared among the different reconstructed data sets. Qualitative assessment of image quality was performed by 3 readers. RESULTS: For all energy levels below 70 keV, noise was significantly lower (P ≤ 0.05) and CNRpancreas significantly higher (P < 0.001), with the second-generation monoenergetic algorithm. Furthermore, the second-generation algorithm was less susceptible to variability related to patient body habitus in the selection of the optimal energy level. The maximal CNRpancreas occurred at 40 keV in 98% (58 of 59) of patients with the second-generation monoenergetic algorithm. However, the CNRNC and readers' image quality scores showed that, even with a second-generation monoenergetic algorithm, higher reconstructed energy levels (60-65 keV) represented the optimal energy level. CONCLUSIONS: Second-generation noise-optimized monoenergetic algorithm can improve the image quality of lower-energy monoenergetic images of the pancreas, while decreasing the variability related to patient body habitus in selection of the optimal energy level.