Insights into Long COVID: Unraveling Risk Factors, Clinical Features, Radiological Findings, Functional Sequelae and Correlations: A Retrospective Cohort Study.

BACKGROUND: The long-term symptomatology of COVID-19 has yet to be comprehensively described. The aim of the study was to describe persistent COVID-19 symptoms in a cohort of hospitalized and home-isolated patients. METHODS: A retrospective cohort study was conducted on long COVID patients. Long COVID symptoms were identified, and patients were divided into hospitalized (in-patients) and home-isolated (out-patients) as well as according to the number of symptoms. Patients were examined by a multydisciplinary medical team. Blood tests, high resolution chest computed tomography (CT), physical and infectious examination were performed. Finally, in-patients were evaluated at two time-points: on hospital admission (T0) and after three months from discharge (Tpost). RESULTS: Three hundred and sixty-four COVID-19 patients were enrolled. 82% of patients reported at least one or more symptoms. The most reported symptom was fatigue. Chest CT showed alteration in 76% of patients and pulmonary function alterations were observed in 44.7% of patients. A higher risk of presenting at least one symptom was seen in patients treated with corticosteroid and a higher risk of presenting chest CT residual lesion was observed in hospitalized patients and in patients that received hydroxychloroquine treatment. Moreover, a higher risk of altered pulmonary function was observed in older patients. CONCLUSION: Long-term sequelae are present in a remarkable number of long COVID patients and pose a new challenge to the healthcare system to identify long-lasting effects and improve patients' wellbeing. Multi-disciplinary teams are crucial to develop preventive measures, and clinical management strategies.

Percutaneous thermal segmentectomy for liver malignancies over 3 cm: mid-term oncological performance and predictors of sustained complete response from a multicentric Italian retrospective study.

INTRODUCTION: Percutaneous thermal segmentectomy is a single-step combination of microwave ablation, performed during arterial occlusion obtained with a balloon micro catheter, followed in the same session by balloon-occluded TACE. The aim of this multicenter retrospective study is to report the mid-term oncological performance of this technique for liver malignancies > 3.0 cm and to identify risk factors for the loss of sustained complete response. METHODS: Oncological results were evaluated with CT or MRI according to m-RECIST (HCC) and RECISTv1.1 (metastasis/intra-hepatic cholangiocarcinoma, iCC) at 1-month, 3-6-month and then at regular-6-month intervals. To identify predictive variables associated with not achieving or losing complete response two mixed-effects multivariable logistic regression models were constructed. RESULTS: Sixty-three patients (40/23, male/female) with primary liver malignancies (HCC = 49; iCC = 4) and metastasis (n = 10) were treated. Median diameter of target lesion was 4.5 cm (range 3.0-7.0 cm). The median follow-up time was 9.2 months. At one-month follow-up, 79.4% of patients presented with a complete response and the remaining 20.6% were partial responders. At the 3-6-month follow-up, reached by 59 of the initial 63 patients, 83.3% showed a sustained complete response, while 10.2% had a partial response and 8.5% a local recurrence. At the last follow-up, 69.8% of the lesions showed a complete response. The initial diameter of the target lesion ≥ 5.0 cm was the only independent variable associated with the risk of failure in maintaining a complete response at 6 months (OR = 8.58, 95% CI 1.38-53.43; P = 0.02). CONCLUSION: Percutaneous thermal segmentectomy achieves promising oncological results in patients with tumors > 3.0 cm, with tumor dimension ≥ 5.0 cm being the only risk factor associated with the failure of a sustained complete response.

The New Frontiers of Fetal Imaging: MRI Insights into Cardiovascular and Thoracic Structures.

Fetal magnetic resonance imaging (fMRI) represents a second-line imaging modality that provides multiparametric and multiplanar views that are crucial for confirming diagnoses, detecting associated pathologies, and resolving inconclusive ultrasound findings. The introduction of high-field magnets and new imaging sequences has expanded MRI's role in pregnancy management. Recent innovations in ECG-gating techniques have revolutionized the prenatal evaluation of congenital heart disease by synchronizing imaging with the fetal heartbeat, thus addressing traditional challenges in cardiac imaging. Fetal cardiac MRI (fCMR) is particularly valuable for assessing congenital heart diseases, especially when ultrasound is limited by poor imaging conditions. fCMR allows for detailed anatomical and functional evaluation of the heart and great vessels and is also useful for diagnosing additional anomalies and analyzing blood flow patterns, which can aid in understanding abnormal fetal brain growth and placental perfusion. This review emphasizes fMRI's potential in evaluating cardiac and thoracic structures, including various gating techniques like metric optimized gating, self-gating, and Doppler ultrasound gating. The review also covers the use of static and cine images for structural and functional assessments and discusses advanced techniques like 4D-flow MRI and T1 or T2 mapping for comprehensive flow quantification and tissue characterization.

Circulating adipose-tissue miRNAs in gastrointestinal cancer patients and their association with the level and type of adiposity at body composition analysis.

Background: Adipose tissue (AT) wasting in cancer is an early catabolic event with negative impact on outcomes. Circulating miRNAs may promote body weight loss and cachexia. We measured circulating miRNAs linked to AT alterations and compared their levels between i) gastrointestinal (GI) cancer patients and controls, ii) cachectic and non-cachectic cancer patients, and iii) according to adiposity level and its distribution. Methods: Patients with GI cancer and subjects with benign diseases as controls were considered. Cachexia was assessed and adiposity evaluated by CT-scan for subcutaneous AT area (SAT), visceral AT area and the total AT area (TAT). MiRNAs involved were measured in plasma by RT-qPCR. Results: 37 naïve GI cancer patients and 14 controls were enrolled. Patients with cachexia presented with lower SAT compared to non-cachectic (p < 0.05). In cancer patients, we found higher levels of miR-26a, miR-128, miR-155 and miR-181a vs. controls (p < 0.05). Cancer patients with BMI < 25 kg/m2 showed higher levels of miR-26a vs. those with BMI ≥ 25 (p = 0.035). MiR-26a and miR-181a were higher in cachectic and non-cachectic vs. controls (p < 0.05). Differences between cachectic and controls were confirmed for miR-155 (p < 0.001) but not between non-cachectic vs. control (p = 0.072). MiR-155 was higher in cachectic patients with low TAT vs. those without cachexia and high TAT (p = 0.036). Conclusion: Our data confirm a modulation of specific and different miRNAs involved in AT metabolism in cancer and cachexia. MiR-155 levels were higher in patients presenting with cachexia and low adiposity with implications in the pathogenic mechanisms and clinical consequences of GI cancer patients.

Long-Term Outcomes of Balloon TACE for HCC: An European Multicentre Single-Arm Retrospective Study.

PURPOSE: To report response rates (using mRECIST), overall survival (OS), progression-free survival and local tumour recurrence-free survival (LRFS) of balloon-occluded transarterial chemoembolisation (bTACE) for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Patients from five European centres treated with conventional or drug-eluting microsphere bTACE for HCC were included, and patients already lost to follow-up before 12 months were excluded. Possible factors contributing to LRFS and OS were evaluated with Cox proportional hazards models. RESULTS: Seventy-three patients were enrolled. The mean number of nodules per patient was 2.07(± 1.68), and the average maximum diameter of the nodules was 37 ± 19.9 mm. The response of the target lesion at 6 months was complete response (CR) in 58.9%, partial response (PR) in 28.8%, stable disease (SD) in 6.8% and progressive disease (PD) in 5.5%. The median follow-up time was 31 months; at the last follow-up, target tumour response was CR in 49.3%, PR in 12.3%, SD in 5.5% and PD 32.9%. Overall response at the last follow-up was CR in 17.8%, PR in 9.6%, SD 2.7% and PD in 69.9% (for new lesions in 37% of patients). Median OS was not reached; mean overall survival was 50.0 months, while median LRFS was 31.0 months. At uni- and multivariable analysis, only tumour maximum diameter was related to LRFS (hazard ratio [HR] = 1.021; 95% CI 1.004-1.038, P = 0.015). CONCLUSIONS: bTACE demonstrated high efficacy for HCC, with a complete response in 58.9% of patients, a median local recurrence-free survival of 31.0 months and a mean overall survival of 50.0 months.

What the urologist needs to know before radical prostatectomy: MRI effective support to pre-surgery planning.

BACKGROUND: Radical prostatectomy (RP) is recommended in case of localized or locally advanced prostate cancer (PCa), but it can lead to side effects, including urinary incontinence (UI) and erectile dysfunction (ED). Magnetic resonance imaging (MRI) is recommended for PCa diagnosis and staging, but it can also improve preoperative risk-stratification. PURPOSE: This nonsystematic review aims to provide an overview on factors involved in RP side effects, highlighting anatomical and pathological aspects that could be included in a structured report. EVIDENCE SYNTHESIS: Considering UI evaluation, MR can investigate membranous urethra length (MUL), prostate volume, the urethral sphincter complex, and the presence of prostate median lobe. Longer MUL measurement based on MRI is linked to a higher likelihood of achieving continence restoration. For ED assessment, MRI and diffusion tensor imaging identify the neurovascular bundle and they can aid in surgery planning. Finally, MRI can precisely describe extra-prostatic extension, prostate apex characteristics and lymph-node involvement, providing valuable preoperative information for PCa treatment. CONCLUSIONS: Anatomical principals structures involved in RP side effects can be assessed with MR. A standardized MR report detailing these structures could assist urologists in planning optimal and tailored surgical techniques, reducing complications, and improving patients' care.

The spectrum of cardiac abnormalities in patients with acromegaly: results from a case-control cardiac magnetic resonance study.

PURPOSE: Cardiac abnormalities are common in patients with acromegaly, contributing to the increased morbidity and mortality. Cardiac magnetic resonance (CMR) is the gold standard for measuring cardiac morpho-functional changes. This study aims to detect cardiac alterations in acromegaly through CMR, even when the disease is adequately controlled. METHODS: In this, multicentre, case-control study, we compared consecutive patients with acromegaly, cured after surgery or requiring medical treatment, with matched controls recruited among patients harbouring non-functioning adrenal incidentalomas. RESULTS: We included 20 patients with acromegaly (7 females, mean age 50 years) and 17 controls. Indexed left ventricular-end-diastolic volume (LV-EDVi) and LV-end-systolic volume (LV-ESVi) were higher in patients than in controls (p < 0.001), as were left ventricular mass (LVMi) (p = 0.001) and LV-stroke volume (LV-SVi) (p = 0.028). Right ventricle (RV) EDVi and ESVi were higher, whereas RV-ejection fraction (RV-EF) was lower (p = 0.002) in patients than in controls (p < 0.001). No significant differences were observed in the prevalence of cardiometabolic comorbidities, including hypertension, glucose and lipid metabolism impairment, obstructive sleep apnoea syndrome, and obesity. IGF1 x upper limit of normal significantly predicted LVMi (b = 0.575; p = 0.008). Subgroup analysis showed higher LVMi (p = 0.025) and interventricular septum thickness (p = 0.003) in male than female patients, even after adjusting cardiac parameters for confounding factors. CONCLUSIONS: The CMR analysis reveals a cluster of biventricular structural and functional impairment in acromegaly, even when the biochemical control if achieved. These findings appear specifically triggered by the exposure to GH-IGF1 excess and show sex-related differences advocating a possible interaction with sex hormones in cardiac disease progression.

Ventilatory efficiency in long-term dyspnoeic patients following COVID-19 pneumonia.

BACKGROUND: Long COVID is defined as persistency of symptoms, such as exertional dyspnea, twelve weeks after recovery from SARS-CoV-2 infection. OBJECTIVES: To investigate ventilatory efficiency by the use of cardiopulmonary exercise testing (CPET) in patients with exertional dyspnea despite normal basal spirometry after 18 (T18) and 36 months (T36) from COVID-19 pneumonia. METHODS: One hundred patients with moderate-critical COVID-19 were prospectively enrolled in our Long COVID program. Medical history, physical examination and lung high-resolution computed tomography (HRCT) were obtained at hospitalization (T0), 3 (T3) and 15 months (T15). All HRCTs were revised using a semi-quantitative CT severity score (CSS). Pulmonary function tests were obtained at T3 and T15. CPET was performed in a subset of patients with residual dyspnea (mMRC ≥ 1), at T18 and at T36. RESULTS: Remarkably, at CPET, ventilatory efficiency was reduced both at T18 (V'E/V'CO2 slope = 31.4±3.9 SD) and T36 (V'E/V'CO2 slope = 31.28±3.70 SD). Furthermore, we identified positive correlations between V'E/V'CO2 slope at T18 and T36 and both percentage of involvement and CSS at HRCT at T0, T3 and T15. Also, negative linear correlations were found between V'E/V'CO2 slope at T18 and T36 and DLCO at T3 and T15. CONCLUSIONS: At eighteen months from COVID-19 pneumonia, 20 % of subjects still complains of exertional dyspnea. At CPET this may be explained by persistently reduced ventilatory efficiency, possibly related to the degree of lung parenchymal involvement in the acute phase of infection, likely reflecting a damage in the pulmonary circulation.

The performance of the node reporting and data system 1.0 (Node-RADS) and DWI-MRI in staging patients with cervical carcinoma according to the new FIGO classification (2018).

PURPOSE: To evaluate the diagnostic accuracy of the Node-RADS score and the utility of apparent diffusion coefficient (ADC) values in predicting metastatic lymph nodes (LNs) involvement in cervical cancer (CC) patients using magnetic resonance imaging (MRI). The applicability of the Node RADS score across three readers with different years of experience in pelvic imaging was also assessed. MATERIAL AND METHODS: Among 140 patients, 68 underwent staging MRI, neoadjuvant chemotherapy and radical surgery, forming the study cohort. Node-RADS scores of the main pelvic stations were retrospectively determined to assess LN metastatic likelihood and compared with the histological findings. Mean ADC, relative ADC (rADC), and correct ADC (cADC) values of LNs classified as Node-RADS ≥ 3 were measured and compared with histological reports, considered as gold standard. RESULTS: Sensitivity, specificity, positive and negative predictive values (PPVs and NPVs), and accuracy were calculated for different Node-RADS thresholds. Node RADS ≥ 3 showed a sensitivity of 92.8% and specificity of 72.5%. Node RADS ≥ 4 yielded a sensitivity of 71.4% and specificity of 100%, while Node RADS 5 yielded 42.9% and 100%, respectively. The diagnostic performance of mean ADC, cADC and rADC values from 78 LNs with Node-RADS score ≥ 3 was assessed, with ADC demonstrating the highest area under the curve (AUC 0.820), compared to cADC and rADC values. CONCLUSION: The Node-RADS score provides a standardized LNs assessment, enhancing diagnostic accuracy in CC patients. Its ease of use and high inter-observer concordance support its clinical utility. ADC measurement of LNs shows promise as an additional tool for optimizing patient diagnostic evaluation.

Cardiac magnetic resonance reveals biventricular impairment in Cushing's syndrome: a multicentre case-control study.

PURPOSE: Cushing's syndrome (CS) is associated with severe cardiovascular (CV) morbidity and mortality. Cardiac magnetic resonance (CMR) is the non-invasive gold standard for assessing cardiac structure and function; however, few CMR studies explore cardiac remodeling in patients exposed to chronic glucocorticoid (GC) excess. We aimed to describe the CMR features directly attributable to previous GC exposure in patients with cured or treated endogenous CS. METHODS: This was a prospective, multicentre, case-control study enrolling consecutive patients with cured or treated CS and patients harboring non-functioning adrenal incidentalomas (NFAI), comparable in terms of sex, age, CV risk factors, and BMI. All patients were in stable condition and had a minimum 24-month follow-up. RESULTS: Sixteen patients with CS and 15 NFAI were enrolled. Indexed left ventricle (LV) end-systolic volume and LV mass were higher in patients with CS (p = 0.027; p = 0.013); similarly, indexed right ventricle (RV) end-diastolic and end-systolic volumes were higher in patients with CS compared to NFAI (p = 0.035; p = 0.006). Morphological alterations also affected cardiac function, as LV and RV ejection fractions decreased in patients with CS (p = 0.056; p = 0.044). CMR features were independent of metabolic status or other CV risk factors, with fasting glucose significantly lower in CS remission than NFAI (p < 0.001) and no differences in lipid levels or blood pressure. CONCLUSION: CS is associated with biventricular cardiac structural and functional impairment at CMR, likely attributable to chronic exposure to cortisol excess independently of known traditional risk factors.

Two-dimensional perfusion angiography permits direct visualization of redistribution of flow in hepatocellular carcinoma during b-TACE.

OBJECTIVES: To demonstrate in vivo redistribution of the blood flow towards HCC's lesions by utilizing two-dimensional perfusion angiography in b-TACE procedures. MATERIAL AND METHODS: In total, 30 patients with 35 HCC nodules treated in the period between January 2019 and November 2021. For each patient, a post-processing software leading to a two-dimensional perfusion angiography was applied on each angiography performed via balloon microcatheter, before and after inflation. On the colour map obtained, reflecting the evolution of contrast intensity change over time, five regions of interests (ROIs) were assessed: one on the tumour (ROI-t), two in the immediate peritumoural healthy liver parenchyma (ROI-ihl) and two in the peripheral healthy liver parenchyma (ROI-phl). The results have been interpreted with a novel in silico model that simulates the hemodynamics of the hepatic arterial system. RESULTS: Among the ROIs drawn inside the same segment of target lesion, the time-to-peak of the ROI-t and of the ROI-ihl have a significantly higher mean value when the balloon was inflated compared with the ROIs obtained with deflated balloon (10.33 ± 3.66 s vs 8.87 ± 2.60 s (p = 0.015) for ROI-t; 10.50 ± 3.65 s vs 9.23 ± 2.70 s (p = 0.047) for ROI-ihl). The in silico model prediction time-to-peak delays when balloon was inflated, match with those observed in vivo. The numerical flow analysis shows how time-to-peak delays are caused by the obstruction of the balloon-occluded artery and the opening of intra-hepatic collateral. CONCLUSION: The measurements identify predictively the flow redistribution in the hepatic arteries during b-TACE, supporting a proper positioning of the balloon microcatheter.

Imaging biomarkers in cardiac CT: moving beyond simple coronary anatomical assessment.

Cardiac computed tomography angiography (CCTA) is considered the standard non-invasive tool to rule-out obstructive coronary artery disease (CAD). Moreover, several imaging biomarkers have been developed on cardiac-CT imaging to assess global CAD severity and atherosclerotic burden, including coronary calcium scoring, the segment involvement score, segment stenosis score and the Leaman-score. Myocardial perfusion imaging enables the diagnosis of myocardial ischemia and microvascular damage, and the CT-based fractional flow reserve quantification allows to evaluate non-invasively hemodynamic impact of the coronary stenosis. The texture and density of the epicardial and perivascular adipose tissue, the hypodense plaque burden, the radiomic phenotyping of coronary plaques or the fat radiomic profile are novel CT imaging features emerging as biomarkers of inflammation and plaque instability, which may implement the risk stratification strategies. The ability to perform myocardial tissue characterization by extracellular volume fraction and radiomic features appears promising in predicting arrhythmogenic risk and cardiovascular events. New imaging biomarkers are expanding the potential of cardiac CT for phenotyping the individual profile of CAD involvement and opening new frontiers for the practice of more personalized medicine.

Takotsubo syndrome: left atrial and ventricular myocardial strain impairment in the subacute and convalescent phases assessed by CMR.

BACKGROUND: We investigated the differences in impairment of left ventricle (LV) and left atrium (LA) contractile dysfunction between subacute and convalescent takotsubo syndrome (TTS), using myocardial strain analysis by cardiac magnetic resonance (CMR) feature-tracking technique. METHODS: We retrospectively selected 50 patients with TTS clinical-radiological diagnosis who underwent CMR within 30 days since symptoms onset: 19 studied during the early subacute phase (sTTS, ≤ 7 days) and 31 during the convalescence (cTTS, 8-30 days). We measured the following: LV global longitudinal, circumferential, and radial strain (lvGLS, lvGCS, lvGRS) and strain rate (SR) and LA reservoir (laS_r), conduit (laS_cd), and booster pump strain (laS_bp) and strain rate (laSR_r, laSR_cd, laSR_bp). Patients were compared with 30 age- and sex-matched controls. RESULTS: All patients were women (mean age 63 years). TTS patients showed altered LV- and LA-strain features, compared to controls. sTTS was associated with increased laS_bp (12.7% versus 9.8%) and reduced lvEF (47.4% versus 54.8%), lvGLS (-12.2% versus 14.6%), and laS_cd (7.0% versus 9.5%) compared to cTTS (p ≤ 0.029). The interval between symptoms onset and CMR was correlated with laS_bp (r = -0.49) and lvGLS (r = 0.47) (p = 0.001 for both). At receiver operating characteristics analysis, laS_bp was the best discriminator between sTTS and cTTS (area under the curve [AUC] 0.815), followed by lvGLS (AUC 0.670). CONCLUSIONS: LA dysfunction persists during the subacute and convalescence of TTS. laS_bp increases in subacute phase with progressive decrease during convalescence, representing a compensatory mechanism of LV dysfunction and thus a useful index of functional recovery. RELEVANCE STATEMENT: Atrial strain has the potential to enhance the delineation of cardiac injury and functional impairment in TTS patients, assisting in the identification of individuals at higher risk and facilitating the implementation of more targeted and personalized medical therapies. KEY POINTS: • In TTS, after ventricular recovery, atrial dysfunction persists assessable with CMR feature tracking. • Quantitative assessment of atrial strain discriminates atrial functions: reservoir, conduit, and booster pump. • Atrial booster pump changes after acute TTS, regardless of ventricular function. • Atrial strain may serve as a temporal marker in TTS.

Competence of radiologists in cardiac CT and MR imaging in Europe: insights from the ESCR Registry.

RATIONALE: To provide an overview of the current status of cardiac multimodality imaging practices in Europe and radiologist involvement using data from the European Society of Cardiovascular Radiology (ESCR) MRCT-registry. MATERIALS AND METHODS: Numbers on cardiac CT and MRI examinations were extracted from the MRCT-registry of the ESCR, entered between January 2011 and October 2023 (n = 432,265). Data collection included the total/annual numbers of examinations, indications, complications, and reporting habits. RESULTS: Thirty-two countries contributed to the MRCT-registry, including 29 European countries. Between 2011 and 2022, there was a 4.5-fold increase in annually submitted CT examinations, from 3368 to 15,267, and a 3.8-fold increase in MRI examinations, from 3445 to 13,183. The main indications for cardiac CT were suspected coronary artery disease (CAD) (59%) and transcatheter aortic valve replacement planning (21%). The number of patients with intermediate pretest probability who underwent CT for suspected CAD showed an increase from 61% in 2012 to 82% in 2022. The main MRI indications were suspected myocarditis (26%), CAD (21%), and suspected cardiomyopathy (19%). Adverse event rates were very low for CT (0.3%) and MRI (0.7%) examinations. Reporting of CT and MRI examinations was performed mainly by radiologists (respectively 76% and 71%) and, to a lesser degree, in consensus with non-radiologists (19% and 27%, respectively). The remaining examinations (4.9% CT and 1.7% MRI) were reported by non-radiological specialties or in separate readings of radiologists and non-radiologists. CONCLUSIONS: Real-life data on cardiac imaging in Europe using the largest available MRCT-registry demonstrate a considerable increase in examinations over the past years, the vast majority of which are read by radiologists. These findings indicate that radiologists contribute to meeting the increasing demands of competent and effective care in cardiac imaging to a relevant extent. CLINICAL RELEVANCE STATEMENT: The number of cardiac CT and MRI examinations has risen over the past years, and radiologists read the vast majority of these studies as recorded in the MRCT-registry. KEY POINTS: • The number of cardiac imaging examinations is constantly increasing. • Radiologists play a central role in providing cardiac CT and MR imaging services to a large volume of patients. • Cardiac CT and MR imaging examinations performed and read by radiologists show a good safety profile.

MRI for risk stratification of muscle invasion by upper tract urothelial carcinoma: a feasibility study.

BACKGROUND: Magnetic resonance imaging (MRI) is recommended in patients with upper tract urothelial carcinoma (UTUC) only when computed tomography (CT) is contraindicated. However, CT does not allow distinguishing ureter wall layers, making impossible to assess muscle invasion, a factor contributing to differentiate high- from low-risk UTUCs, which require different therapeutic approaches. We investigated the feasibility of MRI assessment of UTUC muscle invasion. METHODS: From June 2022 to March 2023, we prospectively enrolled patients suspected of UTUC, i.e., with positive urinary tract ultrasound and/or ureteroscopy, or positive urinary cytology and/or hematuria but negative cystoscopy and bladder ultrasound at two Italian centers. They underwent CT followed by MRI (≤ 24 h apart), independently reported by two experienced radiologists, blinded from histopathology results. After imaging confirmation, they all underwent nephroureterectomy and histopathology analysis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the receiver operating characteristic curve (AUC) were calculated. RESULTS: Thirty-nine lesions were detected in 30 patients on both CT and MRI. Muscle-invasive UTUC prevalence was 81% (21/26) among patients with MRI suspicion and 8% (1/13) among those without MRI suspicion (p < 0.001). Considering the assessment of muscle-layer invasion, the more experienced reader achieved 95% sensitivity (95% confidence interval 82-100), 71% specificity (47-88), 81% PPV (63-93), 92% NPV (70-100), 85% accuracy (67-96), and 0.84 AUC (0.70-0.98). Inter-reader agreement was substantial (κ = 0.73). CONCLUSIONS: MRI showed a promising diagnostic performance for the assessment of UTUC risk of muscle invasion. RELEVANCE STATEMENT: Resulting feasible both in technical and clinical terms, MRI could be helpful for upper tract urothelial carcinomas pre-operative risk stratification, to allow a personalized patients' management. These results play in favor of promoting preoperative MRI for UTUC, as already proven for bladder cancer. KEY POINTS: • Muscle invasion is a crucial information for tailored treatments of upper tract urothelial carcinomas. • CT does not distinguish ureter wall layers, making muscle invasion risk assessment not feasible. • MRI was shown to reliably diagnose muscle-layer invasion by upper tract urothelial carcinomas (sensitivity 95%, specificity 71%).

Diffusion-sensitized magnetic resonance imaging highlights placental microstructural damage in patients with previous SARS-CoV-2 pregnancy infection.

INTRODUCTION: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been a major global health problem since December 2019. This work aimed to investigate whether pregnant women's mild and moderate SARS-CoV-2 infection was associated with microstructural and vascular changes in the placenta observable in vivo by Intravoxel Incoherent Motion (IVIM) at different gestational ages (GA). METHODS: This was a retrospective, nested case-control of pregnant women during the SARS-CoV-2 pandemic (COVID-19 group, n = 14) compared to pre-pandemic healthy controls (n = 19). MRI IVIM protocol at 1.5T was constituted of diffusion-weighted (DW) images with TR/TE = 3100/76 ms and 10 b-values (0,10,30,50,75,100,200,400,700,1000s/mm2). Differences between IVIM parameters D (diffusion), and f (fractional perfusion) quantified in the two groups were evaluated using the ANOVA test with Bonferroni correction and linear correlation between IVIM metrics and GA, COVID-19 duration, the delay time between a positive SARS-CoV-2 test and MRI examination (delay-time exam+) was studied by Pearson-test. RESULTS: D was significantly higher in the COVID-19 placentas compared to that of the age-matched healthy group (p < 0.04 in fetal and p < 0.007 in maternal site). No significant difference between f values was found in the two groups suggesting no-specific microstructural damage with no perfusion alteration (potentially quantified by f) in mild/moderate SARS-Cov-2 placentas. A significant negative correlation was found between D and GA in the COVID-19 placentas whereas no significant correlation was found in the control placentas reflecting a possible accelerated senescence process due to COVID-19. DISCUSSION: We report impaired microstructural placental development during pregnancy and the absence of perfusion-IVIM parameter changes that may indicate no perfusion changing through microvessels and microvilli in the placentas of pregnancies with mild/moderate SARS-Cov-2 after reaching negativity.

Two-Compartment Perfusion MR IVIM Model to Investigate Normal and Pathological Placental Tissue.

BACKGROUND: Perfusion and diffusion coexist in the placenta and can be altered by pathologies. The two-perfusion model, where f1 and, f2 are the perfusion-fraction of the fastest and slowest perfusion compartment, respectively, and D is the diffusion coefficient, may help differentiate between normal and impaired placentas. PURPOSE: Investigate the potential of the two-perfusion IVIM model in differentiating between normal and abnormal placentas. STUDY-TYPE: Retrospective, case-control. POPULATION: 43 normal pregnancy, 9 fetal-growth-restriction (FGR), 6 small-for-gestational-age (SGA), 4 accreta, 1 increta and 2 percreta placentas. FIELD STRENGTH/SEQUENCE: Diffusion-weighted-echo planar imaging sequence at 1.5 T. ASSESSMENT: Voxel-wise signal-correction and fitting-controls were used to avoid overfitting obtaining that two-perfusion model fitted the observed data better than the IVIM model (Akaike weight: 0.94). The two-perfusion parametric-maps were quantified from ROIs in the fetal and maternal placenta and in the accretion zone of accreta placentas. The diffusion coefficient D was evaluated using a b ≥ 200 sec/mm2 -mono-exponential decay fit. IVIM metrics were quantified to fix f1 + f2 = fIVIM . STATISTICAL-TESTS: ANOVA with Dunn-Sidák's post-hoc correction and Cohen's d test were used to compare parameters between groups. Spearman's coefficient was evaluated to study the correlation between variables. A P-value<0.05 indicated a statistically significant difference. RESULTS: There was a significant difference in f1 between FGR and SGA, and significant differences in f2 and fIVIM between normal and FGR. The percreta + increta group showed the highest f1 values (Cohen's d = -2.66). The f2 between normal and percreta + increta groups showed Cohen's d = 1.12. Conversely, fIVIM had a small effective size (Cohen's d = 0.32). In the accretion zone, a significant correlation was found between f2 and GA (ρ = 0.90) whereas a significant negative correlation was found between fIVIM and D (ρ = -0.37 in fetal and ρ = -0.56 in maternal side) and f2 and D (ρ = -0.38 in fetal and ρ = -0.51 in maternal side) in normal placentas. CONCLUSION: The two-perfusion model provides complementary information to IVIM parameters that may be useful in identifying placenta impairment. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 1.