AI Cardiac MRI Scar Analysis Aids Prediction of Major Arrhythmic Events in the Multicenter DERIVATE Registry.

Background Scar burden with late gadolinium enhancement (LGE) cardiac MRI (CMR) predicts arrhythmic events in patients with postinfarction in single-center studies. However, LGE analysis requires experienced human observers, is time consuming, and introduces variability. Purpose To test whether postinfarct scar with LGE CMR can be quantified fully automatically by machines and to compare the ability of LGE CMR scar analyzed by humans and machines to predict arrhythmic events. Materials and Methods This study is a retrospective analysis of the multicenter, multivendor CarDiac MagnEtic Resonance for Primary Prevention Implantable CardioVerter DebrillAtor ThErapy (DERIVATE) registry. Patients with chronic heart failure, echocardiographic left ventricular ejection fraction (LVEF) of less than 50%, and LGE CMR were recruited (from January 2015 through December 2020). In the current study, only patients with ischemic cardiomyopathy were included. Quantification of total, dense, and nondense scars was carried out by two experienced readers or a Ternaus network, trained and tested with LGE images of 515 and 246 patients, respectively. Univariable and multivariable Cox analyses were used to assess patient and cardiac characteristics associated with a major adverse cardiac event (MACE). Area under the receiver operating characteristic curve (AUC) was used to compare model performances. Results In 761 patients (mean age, 65 years ± 11, 671 men), 83 MACEs occurred. With use of the testing group, univariable Cox-analysis found New York Heart Association class, left ventricle volume and/or function parameters (by echocardiography or CMR), guideline criterion (LVEF of ≤35% and New York Heart Association class II or III), and LGE scar analyzed by humans or the machine-learning algorithm as predictors of MACE. Machine-based dense or total scar conferred incremental value over the guideline criterion for the association with MACE (AUC: 0.68 vs 0.63, P = .02 and AUC: 0.67 vs 0.63, P = .01, respectively). Modeling with competing risks yielded for dense and total scar (AUC: 0.67 vs 0.61, P = .01 and AUC: 0.66 vs 0.61, P = .005, respectively). Conclusion In this analysis of the multicenter CarDiac MagnEtic Resonance for Primary Prevention Implantable CardioVerter DebrillAtor ThErapy (DERIVATE) registry, fully automatic machine learning-based late gadolinium enhancement analysis reliably quantifies myocardial scar mass and improves the current prediction model that uses guideline-based risk criteria for implantable cardioverter defibrillator implantation. ClinicalTrials.gov registration no.: NCT03352648 Published under a CC BY 4.0 license. Supplemental material is available for this article.

Imaging for the assessment of the arrhythmogenic potential of mitral valve prolapse.

Mitral valve prolapse (MVP) is the most common valve disease in the western world and recently emerged as a possible substrate for sudden cardiac death (SCD). It is estimated an annual risk of sudden cardiac death of 0.2 to 1.9% mostly caused by complex ventricular arrhythmias (VA). Several mechanisms have been recognized as potentially responsible for arrhythmia onset in MVP, resulting from the combination of morpho-functional abnormality of the mitral valve, structural substrates (regional myocardial hypertrophy, fibrosis, Purkinje fibers activity, inflammation), and mechanical stretch. Echocardiography plays a central role in MVP diagnosis and assessment of severity of regurgitation. Several abnormalities detectable by echocardiography can be prognostic for the occurrence of VA, from morphological alteration including leaflet redundancy and thickness, mitral annular dilatation, and mitral annulus disjunction (MAD), to motion abnormalities detectable with "Pickelhaube" sign. Additionally, speckle-tracking echocardiography may identify MVP patients at higher risk for VA by detection of increased mechanical dispersion. On the other hand, cardiac magnetic resonance (CMR) has the capability to provide a comprehensive risk stratification combining the identification of morphological and motion alteration with the detection of myocardial replacement and interstitial fibrosis, making CMR an ideal method for arrhythmia risk stratification in patients with MVP. Finally, recent studies have suggested a potential role in risk stratification of new techniques such as hybrid PET-MR and late contrast enhancement CT. The purpose of this review is to provide an overview of the mitral valve prolapse syndrome with a focus on the role of imaging in arrhythmic risk stratification. CLINICAL RELEVANCE STATEMENT: Mitral valve prolapse is the most frequent valve condition potentially associated with arrhythmias. Imaging has a central role in the identification of anatomical, functional, mechanical, and structural alterations potentially associated with a higher risk of developing complex ventricular arrhythmia and sudden cardiac death. KEY POINTS: • Mitral valve prolapse is a common valve disease potentially associated with complex ventricular arrhythmia and sudden cardiac death. • The mechanism of arrhythmogenesis in mitral valve prolapse is complex and multifactorial, due to the interplay among multiple conditions including valve morphological alteration, mechanical stretch, myocardial structure remodeling with fibrosis, and inflammation. • Cardiac imaging, especially echocardiography and cardiac magnetic resonance, is crucial in the identification of several features associated with the potential risk of serious cardiac events. In particular, cardiac magnetic resonance has the advantage of being able to detect myocardial fibrosis which is currently the strongest prognosticator.

Radiomics and machine learning analysis by computed tomography and magnetic resonance imaging in colorectal liver metastases prognostic assessment.

OBJECTIVE: The aim of this study was the evaluation radiomics analysis efficacy performed using computed tomography (CT) and magnetic resonance imaging in the prediction of colorectal liver metastases patterns linked to patient prognosis: tumor growth front; grade; tumor budding; mucinous type. Moreover, the prediction of liver recurrence was also evaluated. METHODS: The retrospective study included an internal and validation dataset; the first was composed by 119 liver metastases from 49 patients while the second consisted to 28 patients with single lesion. Radiomic features were extracted using PyRadiomics. Univariate and multivariate approaches including machine learning algorithms were employed. RESULTS: The best predictor to identify tumor growth was the Wavelet_HLH_glcm_MaximumProbability with an accuracy of 84% and to detect recurrence the best predictor was wavelet_HLH_ngtdm_Complexity with an accuracy of 90%, both extracted by T1-weigthed arterial phase sequence. The best predictor to detect tumor budding was the wavelet_LLH_glcm_Imc1 with an accuracy of 88% and to identify mucinous type was wavelet_LLH_glcm_JointEntropy with an accuracy of 92%, both calculated on T2-weigthed sequence. An increase statistically significant of accuracy (90%) was obtained using a linear weighted combination of 15 predictors extracted by T2-weigthed images to detect tumor front growth. An increase statistically significant of accuracy at 93% was obtained using a linear weighted combination of 11 predictors by the T1-weigthed arterial phase sequence to classify tumor budding. An increase statistically significant of accuracy at 97% was obtained using a linear weighted combination of 16 predictors extracted on CT to detect recurrence. An increase statistically significant of accuracy was obtained in the tumor budding identification considering a K-nearest neighbors and the 11 significant features extracted T1-weigthed arterial phase sequence. CONCLUSIONS: The results confirmed the Radiomics capacity to recognize clinical and histopathological prognostic features that should influence the choice of treatments in colorectal liver metastases patients to obtain a more personalized therapy.

Drug-resistant epilepsy at the age extremes: Disentangling the underlying etiology.

The incidence of epilepsy is highest at the extreme age ranges: childhood and elderly age. The most common syndromes in these demographics - self-limited epilepsies of childhood and idiopathic generalized epilepsies in pediatric age, focal epilepsy with structural etiology in older people - are expected to be drug responsive. In this work, we focus on such epilepsy types, overviewing the complex clinical background of unexpected drug-resistance. For self-limited epilepsies of childhood and idiopathic generalized epilepsies, we illustrate drug-resistance resulting from syndrome misinterpretation, reason on possible unexpected courses of epilepsy, and explicate the influence of inappropriate treatments. For elderly-onset epilepsy, we show the challenges in differential diagnosis possibly leading to pseudoresistance and analyze how drug-resistant epilepsy can arise in stroke, neurocognitive disorders, brain tumors, and autoimmune encephalitis. In children and senior people, drug-resistance can be regarded as a hint to review the diagnosis or explore alternative therapeutic strategies. Refractory seizures are not only a therapeutic challenge, but also a cardinal sign not to be overlooked in syndromes commonly deemed to be drug-responsive.

Rapid versus slow withdrawal of antiepileptic monotherapy in two-year seizure-free adults patients with epilepsy (RASLOW) study: A pragmatic multicentre, prospective, randomized, controlled study.

PURPOSE: To establish whether a slow or a rapid withdrawal of antiepileptic monotherapy influences relapse rate in seizure-free adults with epilepsy and calculates compliance and differences in the severity of relapses, based on the occurrence of status epilepticus, seizure-related injuries, and death. METHODS: This is a multicentre, prospective, randomized, open label, non-inferiority trial in people aged 16 + years who were seizure-free for more than 2 years. Patients were randomized to slow withdrawal (160 days) or rapid withdrawal (60 days) and were followed for 12 months. The primary outcome was the probability of a first seizure relapse within the 12-months follow-up. The secondary outcomes included the cumulative probability of relapse at 3, 6, 9, and 12 months. A non-inferiority analysis was performed with non-inferiority margin of - 0.15 for the difference between the probabilities of seizure recurrence in slow versus rapid withdrawal. RESULTS: The sample comprised 48 patients, 25 randomized to slow withdrawal and 23 to rapid withdrawal. Median follow-up was 11.9 months. In the intention-to-treat population, 3 patients in the slow-withdrawal group and 1 in the rapid withdrawal group experienced seizure relapses. The corresponding probabilities of seizure recurrence were 0.12 for slow withdrawal and 0.04 for rapid withdrawal, giving a difference of 0.08 (95% CI - 0.12; 0.27), which is entirely above the non-inferiority margin. No patients developed status epilepticus and seizure-related injuries or died. Risks were similar in the Per-Protocol population. CONCLUSIONS: Seizure-relapse rate after drug discontinuation is lower than in other reports, without complications and unrelated to the duration of tapering.

Radiomics in pulmonary neuroendocrine tumours (NETs).

OBJECTIVES: The aim of this single-centre, observational, retrospective study is to find a correlation using Radiomics between the analysis of CT texture features of primary lesion of neuroendocrine (NET) lung cancer subtypes (typical and atypical carcinoids, large and small cell neuroendocrine carcinoma), Ki-67 index and the presence of lymph nodal mediastinal metastases. METHODS: Twenty-seven patients (11 males and 16 females, aged between 48 and 81 years old-average age of 70,4 years) with histological diagnosis of pulmonary NET with known Ki-67 status and metastases who have performed pre-treatment CT in our department were included. All examinations were performed with the same CT scan (Sensation 16-slice, Siemens). The study protocol was a baseline scan followed by 70 s delay acquisition after administration of intravenous contrast medium. After segmentation of primary lesions, quantitative texture parameters of first and higher orders were extracted. Statistics nonparametric tests and linear correlation tests were conducted to evaluate the relationship between different textural characteristics and tumour subtypes. RESULTS: Statistically significant (p < 0.05) differences were seen in post-contrast enhanced CT in multiple first and higher-order extracted parameters regarding the correlation with classes of Ki-67 index values. Statistical analysis for direct acquisitions was not significant. Concerning the correlation with the presence of metastases, one histogram feature (Skewness) and one feature included in the Gray-Level Co-occurrence Matrix (ClusterShade) were significant on contrast-enhanced CT only. CONCLUSIONS: CT texture analysis may be used as a valid tool for predicting the subtype of lung NET and its aggressiveness.

FLORA software: semi-automatic LGE-CMR analysis tool for cardiac lesions identification and characterization.

PURPOSE: Today there is a growing interest in the quantification of late gadolinium enhancement (LGE) in ischemic and non-ischemic cardiac pathologies. We build an automatic self-made free software FLORA (For Late gadOlinium enhanced aReas clAssification) for the recognition, classification and quantification of LGE areas that allows to improve the observer's performances and that homogenizes the evaluations between different operators. MATERIAL AND METHODS: We have retrospectively selected 120 CMR exams: 40-ischemic with evident scar tissue on LGE sequences; 40-non-ischemic cardiomyopathy; 40-any myocardial alteration on CMR, especially on LGE sequences. FLORA's performance was compared to the radiologist's evaluation. RESULTS: FLORA identified both ischemic and non-ischemic myocardial lesions in almost all cases (80/80 and 79/80 for the double-Gaussian fit method and fixed-shift method, respectively, with sensitivity and specificity of 100%/98.8% and 55%/50%, respectively). The best results were obtained from the classification of ischemic myocardial damage, which was correctly identified in 85%-95% of cases. FLORA also increases the agreement between observers and allows a quantitative evaluation of transmurality. CONCLUSIONS: FLORA has proven to be an applicable tool that improves and facilitates the classification of LGE areas allowing their quantification.

Correlation of CT radiomic features for GISTs with pathological classification and molecular subtypes: preliminary and monocentric experience.

PURPOSE: Our primary purpose was to search for computed tomography (CT) radiomic features of gastrointestinal stromal tumors (GISTs) that could potentially correlate with the risk class according to the Miettinen classification. Subsequently, assess the existence of features with possible predictive value in differentiating responder from non-responder patients to first-line therapy with Imatinib. METHODS: A retrospective study design was carried out using data from June 2009 to December 2020. We analyzed all the preoperative CTs of patients undergoing surgery for GISTs. We segmented non-contrast-enhanced CT (NCECT) and contrast-enhanced venous CT (CECT) images obtained either on three different CT scans (heterogeneous cohort) or on a single CT scan (homogeneous cohort). We then divided the patients into two groups according to Miettinen classification criteria and based on the predictive value of response to first-line therapy with Imatinib. RESULTS: We examined 54 patients with pathological confirmation of GISTs. For the heterogeneous cohort, we found a statistically significant relationship between 57 radiomic features for NCECT and 56 radiomic features for CECT using the Miettinen risk classification. In the homogeneous cohort, we found the same relationship between 8 features for the NCECT and 5 features for CECT, all included in the heterogeneous cohort. The various radiomic features are distributed with different values in the two risk stratification groups according to the Miettinen classification. We also found some features for groups predictive of response to first-line therapy with Imatinib. CONCLUSIONS: We found radiomic features that correlate with statistical significance for both the Miettinen risk classification and the molecular subtypes of response. All features found in the homogeneous study cohort were also found in the heterogeneous cohort. CT radiomic features may be useful in assessing the risk class and prognosis of GISTs.

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs): a radiomic model to predict tumor grade.

PURPOSE: The aim of this single-center retrospective study is to assess whether contrast-enhanced computed tomography (CECT) radiomics analysis is predictive of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) grade based on the 2019 World Health Organization (WHO) classification and to establish a tumor grade (G) prediction model. MATERIAL AND METHODS: Preoperative CECT images of 78 patients with GEP-NENs were retrospectively reviewed and divided in two groups (G1-G2 in class 0, G3-NEC in class 1). A total of 107 radiomics features were extracted from each neoplasm ROI in CT arterial and venous phases acquisitions with 3DSlicer. Mann-Whitney test and LASSO regression method were performed in R for feature selection and feature reduction, in order to build the radiomic-based predictive model. The model was developed for a training cohort (75% of the total) and validated on the independent validation cohort (25%). ROC curves and AUC values were generated on training and validation cohorts. RESULTS: 40 and 24 features, for arterial phase and venous phase, respectively, were found to be significant in class distinction. From the LASSO regression 3 and 2 features, for arterial phase and venous phase, respectively, were identified as suitable for groups classification and used to build the tumor grade radiomic-based prediction model. The prediction of the arterial model resulted in AUC values of 0.84 (95% CI 0.72-0.97) and 0.82 (95% CI 0.62-1) for the training cohort and validation cohort, respectively, while the prediction of the venous model yielded AUC values of 0.7877 (95% CI 0.6416-0.9338) and 0.6813 (95% CI 0.3933-0.9693) for the training cohort and validation cohort, respectively. CONCLUSIONS: CT-radiomics analysis may aid in differentiating the histological grade for GEP-NENs.

Recommendations in pre-procedural imaging assessment for TAVI intervention: SIC-SIRM position paper part 2 (CT and MR angiography, standard medical reporting, future perspectives).

Non-invasive cardiovascular imaging owns a pivotal role in the preoperative assessment of patient candidates for transcatheter aortic valve implantation (TAVI), providing a wide range of crucial information to select the patients who will benefit the most and have the procedure done safely. This document has been developed by a joined group of experts of the Italian Society of Cardiology and the Italian Society of Medical and Interventional Radiology and aims to produce an updated consensus statement about the pre-procedural imaging assessment in candidate patients for TAVI intervention. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac and vascular radiology. Part 2 of the document will cover CT and MR angiography, standard medical reporting, and future perspectives.

Is extensive cardiopulmonary screening useful in athletes with previous asymptomatic or mild SARS-CoV-2 infection?

OBJECTIVE: During the COVID-19 pandemic, it is essential to understand if and how to screen SARS-CoV-2-positive athletes to safely resume training and competitions. The aim of this study is to understand which investigations are useful in a screening protocol aimed at protecting health but also avoiding inappropriate examinations. METHODS: We conducted a cohort study of a professional soccer team that is based on an extensive screening protocol for resuming training during the COVID-19 pandemic. It included personal history, antigen swabs, blood tests, spirometry, resting/stress-test ECG with oxygen saturation monitoring, echocardiogram, Holter and chest CT. We also compared the findings with prior data from the same subjects before infection and with data from SARS-CoV-2-negative players. RESULTS: None of the players had positive swab and/or anti-SARS-CoV-2 IgM class antibodies. Out of 30 players, 18 (60%) had IgG class antibodies. None had suffered severe SARS-CoV-2-related disease, 12 (66.7%) had complained of mild COVID-19-related symptoms and 6 (33.3%) were asymptomatic. None of the players we examined revealed significant cardiovascular abnormalities after clinical recovery. A mild reduction in spirometry parameters versus pre-COVID-19 values was observed in all athletes, but it was statistically significant (p<0.05) only in SARS-CoV-2-positive athletes. One SARS-CoV-2-positive player showed increased troponin I level, but extensive investigation did not show signs of myocardial damage. CONCLUSION: In this small cohort of athletes with previous asymptomatic/mild SARS-CoV-2 infection, a comprehensive screening protocol including blood tests, spirometry, resting ECG, stress-test ECG with oxygen saturation monitoring and echocardiogram did not identify relevant anomalies. While larger studies are needed, extensive cardiorespiratory and haematological screening in athletes with asymptomatic/mild SARS-CoV-2 infection appears unnecessary.

Gastrointestinal neuroendocrine neoplasms (GI-NENs): hot topics in morphological, functional, and prognostic imaging.

Neuroendocrine neoplasms (NENs) are heterogeneous tumours with a common phenotype descended from the diffuse endocrine system. NENs are found nearly anywhere in the body but the most frequent location is the gastrointestinal tract. Gastrointestinal neuroendocrine neoplasms (GI-NENs) are rather uncommon, representing around 2% of all gastrointestinal tumours and 20-30% of all primary neoplasms of the small bowel. GI-NENs have various clinical manifestations due to the different substances they can produce; some of these tumours appear to be associated with familial syndromes, such as multiple endocrine neoplasm and neurofibromatosis type 1. The current WHO classification (2019) divides NENs into three major categories: well-differentiated NENs, poorly differentiated NENs, and mixed neuroendocrine-non-neuroendocrine neoplasms. The diagnosis, localization, and staging of GI-NENs include morphology and functional imaging, above all contrast-enhanced computed tomography (CECT), and in the field of nuclear medicine imaging, a key role is played by 68Ga-labelled-somatostatin analogues (68Ga-DOTA-peptides) positron emission tomography/computed tomography (PET/TC). In this review of recent literature, we described the objectives of morphological/functional imaging and potential future possibilities of prognostic imaging in the assessment of GI-NENs.

Real-world clinical validity of cardiac magnetic resonance tissue tracking in primitive hypertrophic cardiomyopathy.

OBJECTIVE: Cardiac magnetic resonance (CMR) is an uncontested diagnostic tool for identifying and assessing hypertrophic cardiomyopathy (HCM) patients. Concerning the necessity to identify valid prognosticators for predicting the individual risk of clinical evolution, this study aimed to evaluate the clinical validity of CMR tissue tracking (TT) analysis in patients affected by primitive HCM in a real-world setting. METHODS: This historical prospective study included 33 patients. Diagnostic validity and clinical validation were assessed for strain values. CMR-TT diagnostic validity was studied comparing HCM patients with healthy control groups and phenotypic presentation of HCM. The impact of strain values and all phenotypic disease characteristics were assessed in a long-term follow-up study. RESULTS: The inter-reading agreement was good for all strain parameters. Significant differences were observed between the control group and HCM patients. Similarly, hypertrophic and LGE + segments showed lower deformability than healthy segments. The AUC of predictive model, including conventional risk factors for MACE occurrence and all strain values, reached 98% of diagnostic concordance (95% CI .94-1; standard error: .02; p value .0001), compared to conventional risk factors only (86%; 95% CI .73-99; standard error: .07; p value .002). CONCLUSION: In patients with primitive HCM, CMR-TT strain proves high clinical validity providing independent and non-negligible prognostic advantages over clinical features and traditional CMR markers.

Epilepsy and brain channelopathies from infancy to adulthood.

Genetic brain channelopathies result from inherited or de novo mutations of genes encoding ion channel subunits within the central nervous system. Most neurological channelopathies arise in childhood with paroxysmal or episodic symptoms, likely because of a transient impairment of homeostatic mechanisms regulating membrane excitability, and the prototypical expression of this impairment is epilepsy. Migraine, episodic ataxia and alternating hemiplegia can also occur, as well as chronic phenotypes, such as spinocerebellar ataxias, intellectual disability and autism spectrum disorder. Voltage-gated and ligand-gated channels may be involved. In most cases, a single gene may be associated with a phenotypical spectrum that shows variable expressivity. Different clinical features may arise at different ages and the adult phenotype may be remarkably modified from the syndrome onset in childhood or adolescence. Recognizing the prominent phenotypical traits of brain channelopathies is essential to perform appropriate diagnostic investigations and to provide the better care not only in the paediatric setting but also for adult patients and their caregivers. Herein, we provide an overview of genetic brain channelopathies associated with epilepsy, highlight the different molecular mechanisms and describe the different clinical characteristics which may prompt the clinician to suspect specific syndromes and to possibly establish tailored treatments.

Cardiac magnetic resonance in hypertrophic and dilated cardiomyopathies.

Cardiomyopathies are a heterogeneous entity. The progress in the field of genetics has allowed over the years to determine its origin more and more often. The classification of these pathologies has changed over the years; it has been updated with new knowledge. Imaging allows to define the phenotypic characteristics of the different forms of cardiomyopathy. Cardiac magnetic resonance (CMR) allows a morphological evaluation of the associated (and sometimes pathognomonic) cardiac findings of any form of cardiomyopathy. The tissue characterization sequences also make magnetic resonance imaging unique in its ability to detect changes in myocardial tissue. This review aims to define the features that can be highlighted by CMR in hypertrophic and dilated forms and the possible differential diagnoses. In hypertrophic forms, CMR provides: precise evaluation of wall thickness in all segments, ventricular function and size and evaluation of possible presence of areas of fibrosis as well as changes in myocardial tissue (measurement of T1 mapping and extracellular volume values). In dilated forms, cardiac resonance is the gold standard in the assessment of ventricular volumes. CMR highlights also the potential alterations of the myocardial tissue.

Diagnostic imaging of typical lung carcinoids: relationship between MDCT, 111In-Octreoscan and 18F-FDG-PET imaging features with Ki-67 index.

AIMS: This study analyses the capability of contrast-enhanced multi-detector computed tomography (MDCT) and spectrum of molecular imaging to characterize typical carcinoids (TCs) of lung and their relationship with Ki-67 index. MATERIALS AND METHODS: We analysed 68 patients with histological diagnosis of pulmonary TC, which underwent both MDCT and nuclear molecular imaging (somatostatin receptor scintigraphy/SPECT with 111In-pentetreotide and 18F-FDG-PET/CT) at staging evaluation before surgery. The MDCT scan was reviewed for the following features: size, margins, contrast enhancement, presence of calcifications, bronchial obstruction, lymph nodes and metastases. In 111In-pentetreotide SPECT, tumour/non-tumour ratio was measured at 4- and 24-h post-injection and the per cent difference was calculated (T/NT%). FDG uptake was measured as the ratio between lesion SUVmax and liver SUVmean (SUV ratio). All imaging features were correlated between them and with Ki-67 index. RESULTS: Forty-four of the 68 lesions (65%) were in the right lung. In MDCT, scan lesions appeared as a well-defined nodule in 44 patients (65%) and irregular mass in 24 patients (35%). Contrast intense enhancement was present in 53 patients (78%), calcifications in 20 patients (29%) and bronchial obstruction in 24 patients (35%). Lymph nodes and metastasis were present in 13 (19%) and 15 (22%) patients. Ki-67 index was negatively correlated with T/NT% and positively with SUV ratio; T/NT% and SUV ratio were inversely correlated. The presence of irregular margins and metastases was negatively related to T/NT%. The presence of a mass, irregular margins, bronchial obstruction, lymph nodes and metastasis was positively related to higher SUV ratio. The presence of irregular margins, bronchial obstruction, lymph nodes and metastases was significantly correlated with a higher grade of Ki-67 index. CONCLUSIONS: MDCT and nuclear molecular imaging are important to characterize lung TCs. The majority of TCs appear as a well-defined nodule generally not associated with extra-thorax signs. We found a significant correlation between some MDCT aspects, nuclear medicine features and Ki-67 index. The association of MDCT and nuclear medicine imaging may be useful in predicting proliferative activity and prognosis of lung TCs.

SDHx and Non-Chromaffin Tumors: A Mediastinal Germ Cell Tumor Occurring in a Young Man with Germline SDHB Mutation.

Background: Mutations in genes encoding one of the subunits of succinate dehydrogenase (SDH) are involved in pheochromocytoma (PHEO) and paraganglioma (PGL) development. Over the last few years, such mutations have also been associated with non-chromaffin tumors. However, immunohistochemistry (IHC) on the tumor tissue and a study on the loss of heterozygosity (LOH) aimed at demonstrating the pathogenic role of SDHx genes have only been employed in a few cases. Case report: We describe the case of a 19-year-old Caucasian man with a germline SDHB mutation, who presented with acne vulgaris resistant to medical treatment. His follow-up for chromaffin tumors was negative, while hormonal tests revealed suppressed gonadotropins with testosterone in the upper range of normality and elevated ß-human chorionic gonadotropin (ß-hCG). At the whole-body enhanced CT scan, a mediastinal lesion suggestive of a germ cell tumor (GCT) was detected. 18FDG-PET (fluorodeoxyglucose-positron emission tomography) imaging showed low glucose metabolism at the mediastinal site. Surgical removal of the mass was uneventful. Pathology confirmed the diagnosis of GCT consisting of cystic teratoma (95%) and seminoma (5%). IHC for SDHB showed normal protein expression, and genetic analysis of the tumor tissue revealed the absence of SDHB LOH. Normalization of the hormonal tests and acne attenuation were achieved after surgery. Conclusion: We report an incidental association of a germinal SDHB mutation and mediastinal GCT in a young Caucasian man. Our paper highlights the importance of IHC and genetic analysis in confirming the etiologic role of SDHx genes in nonchromaffin tumors, thus excluding incidental associations.

Cardiac magnetic resonance in patients with mitral valve prolapse: Focus on late gadolinium enhancement and T1 mapping.

OBJECTIVES: To evaluate the incidence of late-gadolinium-enhancement (LGE) in mitral valve prolapse (MVP) (in the absence of other heart/valvular diseases), and its association with the degree of mitral regurgitation (MR) and/or with complex ventricular arrhythmia (ComVA), and to analyse the role of T1 mapping in the evaluation of MVP patients. METHODS: We included all consecutive patients with MVP who underwent during 2015-2016 a comprehensive cardiac magnetic resonance (CMR) examination at 1.5 T. We evaluated the association of LGE with the MR fraction and the presence of ComVA. We compared myocardial T1-native and post-contrast times and extracellular volume (ECV)-values between MVP patients, both with and without LGE, and the control group. RESULTS: Thirty-four patients with MVP were selected (56 ± 14 years old, 59% male). All patients had MR; LGE and ComVA were present in 15 (44%) and 11 (34%) patients, respectively. Significant associations of LGE with both MR severity and ComVA were not found (p=0.72 and 0.79, respectively). T1 mapping confirmed the presence of LGE in all cases. In one patient a thin signal alteration resulted in more evident T1 mapping than LGE. Patients with MVP had higher native T1-values, lower post-contrast T1-values and increased ECV-values compared with controls (p=0.01, 0.01 and 0.00, respectively). CONCLUSION: Focal fibrosis with LGE was found in about half the MVP patients and it was independent of the degree of the valve dysfunction and the presence of ComVA. T1 mapping allows diffuse myocardial wall alterations to be identified, but no significant associations between the MR severity and ComVA and T1/ECV values were found. KEY POINTS: • MVP is a common valvulopathy affecting 2-3% of the general population. • MVP has been associated with an increased risk of arrhythmic complications and sudden cardiac death. • CMR is a non-invasive imaging method that provides a precise and more accurate assessment of patients with MVP.

Clostridium difficile colitis: CT findings and differential diagnosis.

Clostridium difficile infection (CDI) is a severe and potentially deadly infectious colitis whose incidence is dramatically increasing in the last decades, with more virulent strains. CDI should be suspected in case of unexplained diarrhea and abdominal pain in patients with a recent history of antibiotic use and healthcare exposures; diagnosis is based on a combination of clinical and laboratory findings with demonstration of C. difficile toxins by stool test. The advantages of contrast-enhanced computed tomography (CECT) are the noninvasiveness and the ability to evaluate both the colonic wall and the adjacent soft tissues. Considerable overlap exists between the CECT findings of CDI and those of colitis of other origins, such as typhlitis, ischemic colitis, graft-versus-host disease, radiation colitis and inflammatory bowel diseases; however, some features may help distinguish between these conditions. This paper provides a comprehensive overview of the imaging features of Clostridium difficile colitis and its mimics, with a view to assist the radiologist in reaching the correct diagnosis.

Acute penile trauma: imaging features in the emergency setting.

In an emergency department, penile traumas are uncommon and a prompt diagnosis is necessary. Penile injury may result from penetrating and non-penetrating trauma. Non-penetrating injuries can produce cavernosal hematomas or fractures: if not treated promptly, these lesions can result in fibrosis or erectile dysfunction. Penile traumatic lesions need a clinical approach first, but a radiological study is often required: ultrasonography with color and spectral Doppler study is usually the first approach. In some cases, magnetic resonance imaging may be performed to better recognize even small discontinuity of the tunica albuginea. Radiologists have to be aware of the various radiological patterns of penile traumatic lesions, in order to establish a prompt and correct diagnosis.