Renal MRI: From Nephron to NMR Signal

Renal diseases pose a significant socio-economic burden on healthcare systems. The development of better diagnostics and prognostics is well-recognized as a key strategy to resolve these challenges. Central to these developments are MRI biomarkers, due to their potential for monitoring of early pathophysiological changes, renal disease progression or treatment effects. The surge in renal MRI involves major cross-domain initiatives, large clinical studies, and educational programs. In parallel with these translational efforts, the need for greater (patho)physiological specificity remains, to enable engagement with clinical nephrologists and increase the associated health impact. The ISMRM 2022 Member Initiated Symposium (MIS) on renal MRI spotlighted this issue with the goal of inspiring more solutions from the ISMRM community. This work is a summary of the MIS presentations devoted to: 1) educating imaging scientists and clinicians on renal (patho)physiology and demands from clinical nephrologists, 2) elucidating the connection of MRI parameters with renal physiology, 3) presenting the current state of leading MR surrogates in assessing renal structure and functions as well as their next generation of innovation, and 4) describing the potential of these imaging markers for providing clinically meaningful renal characterization to guide or supplement clinical decision making. We hope to continue momentum of recent years and introduce new entrants to the development process, connecting (patho)physiology with (bio)physics, and conceiving new clinical applications. We envision this process to benefit from cross-disciplinary collaboration and analogous efforts in other body organs, but also to maximally leverage the unique opportunities of renal physiology. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.

Coronary artery disease and revascularization associated with immune checkpoint blocker myocarditis – report from an international registry

Purpose

Immune-checkpoint-blocker (ICB) associated myocarditis (ICB-myocarditis) may present similarly and/or overlap with other cardiac pathology including acute coronary syndrome presenting a challenge for prompt clinical diagnosis.

Methods

An international registry was used to retrospectively identify cases of ICB-myocarditis. Presence of coronary artery disease (CAD) was defined as coronary artery stenosis >70% in patients undergoing coronary angiogram.

Results

Among 261 patients with clinically suspected ICB-myocarditis who underwent a coronary angiography, CAD was present in 59/261 (22.6%) (Table 1). Coronary revascularization was performed during the index hospitalization in 19/59 (32.2%) patients. Patients undergoing coronary revascularization less frequently received steroids administration within 24h of admission compared to the other groups (p=0.029). Myocarditis related 90-day mortality was 9/17 (52.7%) in the revascularized cohort, compared to 5/31 (16.1%) in those not revascularized and 25/156 (16.0%) in those without CAD (p=0.001). irAE-related 90-day mortality was 9/17 (52.7%) in the revascularized cohort, compared to 6/31 (19.4%) in those not revascularized and 31/156 (19.9%) in no CAD groups (p=0.007) (Figure 1). All-cause 90-day mortality was 11/17 (64.7%) in the revascularized cohort, compared to 13/31 (41.9%) in no revascularization and 60/158 (38.0%) in no CAD groups (p=0.10). After adjustment on age and sex, coronary revascularization remained associated with ICB-myocarditis-related death at 90 days (Hazard ratio [HR]=4.03, 95%confidence interval [CI] 1.84–8.84, p<0.001) and was marginally associated with all-cause death (HR=1.88, 95% CI 0.98–3.61, p=0.057).

Conclusion

CAD may exist concomitantly with ICB-myocarditis and portend a poorer outcome when revascularization is performed. This is potentially mediated thru delayed diagnosis and treatment or more severe presentation of ICB-myocarditis.

Funding Acknowledgement

Type of funding sources: None.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Short-term changes observed in multiparametric liver MRI following therapy with direct-acting antivirals in chronic hepatitis C virus patients

Methods

We applied multiparametric MRI to assess changes in liver composition, perfusion and blood flow in 17 patients before direct-acting antiviral (DAA) therapy and after treatment completion (within 12 weeks of last DAA tablet swallowed).

Results

We observed changes in hepatic composition indicated by a reduction in both liver longitudinal relaxation time (T1, 35 ± 4 ms), transverse relaxation time (T2, 2.5 ± 0.8 ms; T2* 3.0 ± 0.7 ms), and liver perfusion (28.1 ± 19.7 ml/100 g/min) which we suggest are linked to reduced pro-inflammatory milieu, including interstitial oedema, within the liver. No changes were observed in liver or spleen blood flow, splenic perfusion, or superior mesenteric artery blood flow.

Conclusion

For the first time, our study has shown that treatment of HCV with DAAs in patients with cirrhosis leads to an acute reduction in liver T1, T2 and T2* and an increase in liver perfusion measured using MR parameters. The ability of MRI to characterise changes in the angio-architecture of patients with cirrhosis after intervention in the short term will enhance our understanding of the natural history of regression of liver disease and potentially influence clinical decision algorithms.

Key Points

• DAAs have revolutionised the treatment of hepatitis C and achieve sustained virological response in over 95% of patients, even with liver cirrhosis.

• Currently available non-invasive measures of liver fibrosis are not accurate after HCV treatment with DAAs, this prospective single-centre study has shown that MRI can sensitively measure changes within the liver, which could reflect the reduction in inflammation with viral clearance.

• The ability of MRI to characterise changes in structural and haemodynamic MRI measures in the liver after intervention will enhance our understanding of the progression/regression of liver disease and could potentially influence clinical decision algorithms.

The ratio of erythrocyte sedimentation rate to C-reactive protein is useful in distinguishing infection from flare in systemic lupus erythematosus patients presenting with fever

Background Both C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) can be elevated in systemic lupus erythematosus (SLE) flare and infection, and are therefore of limited utility for distinguishing between the two conditions in febrile SLE patients. Methods A medical records review of hospitalizations (1997-2006) of SLE patients in the Michigan Lupus Cohort was performed. Eligible hospitalizations were those in which patients presented with a temperature of >100.3°F or with subjective fevers as a presenting complaint at admission. Detailed demographic, clinical, and laboratory data were collected. Multivariable logistic regression was used to examine the associations between ESR and CRP and the outcome of flare vs infection, adjusted for confounders. Results Among 557 SLE patients screened, there were 53 eligible hospitalizations (28 flares and 25 infections). Each unit increase in the ratio of ESR:CRP was associated with a 17% increase in the odds of fever being attributable to SLE flare compared to infection (OR 1.17, 95% CI 1.04, 1.31; p = 0.009), when adjusted for white blood cell count, SLE duration, sex, race, and age. ESR and CRP were not individually associated with flare vs infection when modeled with their ratio. Conclusions The ratio of ESR:CRP may provide diagnostic value beyond individual ESR and CRP levels in distinguishing flare vs infection in SLE patients presenting with fever.

Detection of Salmonella enterica Serovar Montevideo and Newport in Free-ranging Sea Turtles and Beach Sand in the Caribbean and Persistence in Sand and Seawater Microcosms

Salmonellae are Gram-negative zoonotic bacteria that are frequently part of the normal reptilian gastrointestinal flora. The main objective of this project was to estimate the prevalence of non-typhoidal Salmonella enterica in the nesting and foraging populations of sea turtles on St. Kitts and in sand from known nesting beaches. Results suggest a higher prevalence of Salmonella in nesting leatherback sea turtles compared with foraging green and hawksbill sea turtles. Salmonella was cultured from 2/9 and identified by molecular diagnostic methods in 3/9 leatherback sea turtle samples. Salmonella DNA was detected in one hawksbill turtle, but viable isolates were not recovered from any hawksbill sea turtles. No Salmonella was detected in green sea turtles. In samples collected from nesting beaches, Salmonella was only recovered from a single dry sand sample. All recovered isolates were positive for the wzx gene, consistent with the O:7 serogroup. Further serotyping characterized serovars Montevideo and Newport present in cloacal and sand samples. Repetitive-element palindromic PCR (rep-PCR) fingerprint analysis and pulsed-field gel electrophoresis of the 2014 isolates from turtles and sand as well as archived Salmonella isolates recovered from leatherback sea turtles in 2012 and 2013, identified two distinct genotypes and four different pulsotypes, respectively. The genotyping and serotyping were directly correlated. To determine the persistence of representative strains of each serotype/genotype in these environments, laboratory-controlled microcosm studies were performed in water and sand (dry and wet) incubated at 25 or 35°C. Isolates persisted for at least 32 days in most microcosms, although there were significant decreases in culturable bacteria in several microcosms, with the greatest reduction in dry sand incubated at 35°C. This information provides a better understanding of the epizootiology of Salmonella in free-ranging marine reptiles and the potential public health risks associated with human interactions with these animals in the Caribbean.

Dynamics of piscine francisellosis differs amongst tilapia species (Oreochromis spp.) in a controlled challenge with Francisella noatunensis subsp. orientalis

A 25-week immersion challenge was conducted exposing Oreochromis mossambicus, Oreochromis aureus and Oreochromis urolepis hornorum to Francisella noatunensis subsp. orientalis (Fno). Two populations were compared for each fish species; 'resident fish' were defined as fish maintained in tanks since week 0 of challenge, whereas 'naïve fish' were defined as fish added to tanks once temperature in water reached <26 °C at 21 weeks post-challenge. Fno genome equivalents (GEs) in water were similar in all treatments 1 h post-challenge; however, significantly lower Fno GEs were detected 2 weeks post-challenge in all tanks, and the only treatment with detectable Fno GE after 4 weeks of challenge were the O. mossambicus tanks. Twenty-one weeks post-challenge, naïve fish were stocked with 'resident' cohorts. Over a 4-week period, mortalities occurred consistently only in O. mossambicus naïve cohorts. Overall presence of granulomas in spleen of survivors was similar (>55%) in all resident populations; however, in naïve populations, only O. mossambicus presented granulomas. Similarly, only O. mossambicus presented viable Fno in the spleen of survivors, and Fno GEs were only detected in O. mossambicus, and in resident O. aureus. In conclusion, the results of this study suggest different susceptibility of tilapia species to piscine francisellosis.

Supplementary management of benign prostatic hypertrophy with Prostaquil. An 8-week registry

The aim of this registry was to evaluate the management of initial symptoms of benign prostatic hyperthrophy (BPH) in otherwise healthy subjects, using Prostaquil® (Alchem) in a 8-week registry. Prostaquil was used at the dosage of 200 mg/day. The product includes Pygeum extract (100 mg) and Saw palmetto oil (35 mg). The two resulting groups standard management and supplement) were comparable.

RESULTS

No side effects or comparability problems were observed and compliance was optimal with more than 95% of the capsules correctly used. Empting, frequency, intermittency, urgency, weak flow, straining, nocturia were all significantly improved with Prostaquil (p<0.05) and the improvement - globally and evaluating any single item - was significantly superior to the one observed in controls (p<0.05). Quality of life with the supplement was also significantly better in comparison with controls (p<0.05). The residual vescical volume was 94.7;5,8 ml in the supplement group at inclusion and decreased to 39.3;5 ml (p<0.05) at 8 weeks. This decrease was equivalent to a reduction of 58.5%(vs a decrease of 27.9% in controls)(p<0.05; ANOVA). In conclusion, the most common symptoms of BPH are controlled by Prostaquil a new standardized supplement including Pygeum.

FlexiQule (Boswellia extract) in the supplementary management of osteoarthritis: a supplement registry

The aim of the present pilot, registry study was an assessment in a supplement study of FlexiQule (standardized Boswellia extract) capsules in the supplementary management of patients with symptomatic knee osteoarthritis (OA) also treated with the "standard management" (SM) in comparison with a group of patients only managed with SM.

METHODS

This 4-week study included patients with symptomatic knee arthrosis (X-ray). Registry subjects were able to perform a treadmill walking test and to understand questions from the WOMAC questionnaire. Exclusion criteria were conditions requiring drug treatment, Body Mass Index >25, metabolic disorders, surgery within three months prior to inclusion, oncological condition or inability to walk.

RESULTS

Twenty-seven registry subjects using the supplement+SM and 28 using only SM completed the registry; at inclusion, the two groups were comparable including Karnofsky scale, WOMAC Score and the Treadmill Test. Of the subjects completing the registry 24 preferred to use the combination SM and the supplement. Safety evaluation: no problems - indicating the suspension of the supplementation ‑ were observed. Routine blood tests were normal at inclusion and did not significantly vary at 4 weeks. The Karnofski Scale at 4 weeks was improved in both groups: from 74.3;3.1 to 88.9;5.3 (P<0.05) in the Boswellia group in comparison with a variation from 75.3;5.2 to 79.4;3.3 (P<0.05) in the SM. The effects of the supplement were significantly higher (P<0.05). The WOMAC Score was decreased significantly more in the supplement+SM group in comparison with controls considering pain, stiffness and physical functions (P<0.05). Social/emotional functions improved better with the supplement (P<0.05). Both groups improved their walking distance at 4 weeks. The improvement was higher (P<0.05) in the Boswellia group. The need for other drugs or tests during the registry period was reduced more in the supplement group (P<0.05).

CONCLUSION

The difference between SM and the supplementation associated to SM was significant) in favor of the supplementation with Boswellia for all target measurements evaluated in the registry at 4 weeks.

Maternal death review in selected countries of South East Asia Region

Understanding the underlying factors that led to maternal deaths through a maternal death review (MDR) throws light on the causes, characteristics and circumstances of the death. We reviewed and report on the implementation of MDR in India, Indonesia, Myanmar, Nepal and Sri Lanka, capturing the experiences of MDR initiatives, follow-up actions and lessons learnet. Overall, while the findings from MDRs have been used to design or change policies and strategies for improvement of services provided, there are still challenges in scaling up these initiatives, particularly in the larger countries.

Physiological measurements using ultra-high field fMRI: a review

Functional MRI (fMRI) has grown to be the neuroimaging technique of choice for investigating brain function. This topical review provides an outline of fMRI methods and applications, with a particular emphasis on the recent advances provided by ultra-high field (UHF) scanners to allow functional mapping with greater sensitivity and improved spatial specificity. A short outline of the origin of the blood oxygenation level dependent (BOLD) contrast is provided, followed by a review of BOLD fMRI methods based on gradient-echo (GE) and spin-echo (SE) contrast. Phase based fMRI measures, as well as perfusion contrast obtained with the technique of arterial spin labelling (ASL), are also discussed. An overview of 7 T based functional neuroimaging is provided, outlining the potential advances to be made and technical challenges to be addressed.

Serum free light chains, interferon-alpha, and interleukins in systemic lupus erythematosus

OBJECTIVE

Interleukin-6 (IL-6), interleukin-10 (IL-10), interferon-alpha (IFN-α), and free light chains (FLCs: lambda, kappa) have all been noted to be of importance in systemic lupus erythematosus (SLE). Herein, we quantified and explored the relationship between these inflammatory mediators and disease activity in SLE; and stratified by their current anti-dsDNA antibody status.

METHODS

Seventy-seven SLE patients underwent assessment of disease activity using the SLE disease activity index (SLEDAI). Serum FLC (lambda, kappa, and total), IL-6, IL-10, and IFN-α were quantified. Demographics of disease characteristics were determined by chart reviews. Statistical analyses included Mann-Whitney test, chi square, and linear regression analyses.

RESULTS

Mean (SD) age of the patients was 44.9 ± 12.7 years; SLEDAI (mean ± SD) was 3.4 ± 4.0. Serum lambda FLC levels had a moderate correlation (r = 0.46 with physician global assessment, 0.44 with SLEDAI) and the strongest correlation with disease activity as compared with other inflammatory mediators including current dsDNA antibody status. After adjusting for prednisone use, the correlation of lambda FLC with PGA (r = 0.48) and SLEDAI (r = 0.52) was better than of current dsDNA antibody status with PGA (r = 0.33) and adjusted SLEDAI (r = 0.24), respectively. IL-10 and IFN-α activity did not correlate with disease activity. Serum FLC and IL-6 levels could differentiate between active and inactive SLE patients. Serum lambda FLC and IL-6 levels differed significantly among patients with and without current dsDNA antibodies. Serum lambda FLC levels accounted for 31% of variance in SLEDAI scores.

CONCLUSION

Serum FLC and IL-6 are potentially useful biomarkers of disease activity in SLE. Further studies, with larger study sample and longitudinal design, are indicated.

Guidance of growth mode and structural character in organic–inorganic hybrid materials – a comparative study

We investigated the influence of the functionality of organic ligands on film properties in organic–inorganic hybrid thin films deposited by atomic layer deposition.

Infection control in United Kingdom neonatal units: variance in practice and the need for an evidence base

Infection prevention is a cornerstone of good neonatal care. There are, however, few research data to support infection control approaches in this population. Through a structured telephone interview we surveyed all neonatal units in the United Kingdom to identify infection control issues, practices and policies. Eighty seven percent of the 198 neonatal units participated. Twenty one units (12.2%) had closed with infection control issues in the last year; 14.1% had current infection control concerns; 81.5% of units decolonised MRSA positive infants, but over 15 regimens were used. Wide variations in hygiene measures were identified; 22.1% of units used theatre scrubs for all staff, 7.6% used aprons and 5.8% required gloves to be worn when entering clinical areas. Only 54% required hand washing and alcohol gel before entry to a patient care area; 11.6% required only the use of alcohol gel.

Although infection control issues are resulting in neonatal unit closures and risks to patients, there are considerable variations in hygiene and screening practices. There is little data to support the safety or efficacy of decolonisation in neonatal populations, but this is widely practised. Research needs to be carried out to evaluate the effectiveness of screening practices and decolonisation in order that a consistent evidence-based approach can be applied.