Automated image quality assessment for selecting among multiple magnetic resonance image acquisitions in the German National Cohort study.

In magnetic resonance imaging (MRI), the perception of substandard image quality may prompt repetition of the respective image acquisition protocol. Subsequently selecting the preferred high-quality image data from a series of acquisitions can be challenging. An automated workflow may facilitate and improve this selection. We therefore aimed to investigate the applicability of an automated image quality assessment for the prediction of the subjectively preferred image acquisition. Our analysis included data from 11,347 participants with whole-body MRI examinations performed as part of the ongoing prospective multi-center German National Cohort (NAKO) study. Trained radiologic technologists repeated any of the twelve examination protocols due to induced setup errors and/or subjectively unsatisfactory image quality and chose a preferred acquisition from the resultant series. Up to 11 quantitative image quality parameters were automatically derived from all acquisitions. Regularized regression and standard estimates of diagnostic accuracy were calculated. Controlling for setup variations in 2342 series of two or more acquisitions, technologists preferred the repetition over the initial acquisition in 1116 of 1396 series in which the initial setup was retained (79.9%, range across protocols: 73-100%). Image quality parameters then commonly showed statistically significant differences between chosen and discarded acquisitions. In regularized regression across all protocols, 'structured noise maximum' was the strongest predictor for the technologists' choice, followed by 'N/2 ghosting average'. Combinations of the automatically derived parameters provided an area under the ROC curve between 0.51 and 0.74 for the prediction of the technologists' choice. It is concluded that automated image quality assessment can, despite considerable performance differences between protocols and anatomical regions, contribute substantially to identifying the subjective preference in a series of MRI acquisitions and thus provide effective decision support to readers.

Safety and efficacy of two-drug combination in elderly patients with locally advanced non-small cell lung cancer and validation of the Charlson Index as a predictor of survival.

Background: The best platinum-based chemotherapy regimen remains to be determined in elderly patients treated with definitive chemoradiotherapy for advanced non-small cell lung cancer (NSCLC). Predictive indexes for toxicity and survival are also needed to give the safest and most effective treatment for this population. Methods: This is a retrospective cohort study. Patients with histologically confirmed stage IIIA, IIIB or IIIC NSCLC over 70 years of age, treated with radiotherapy and chemotherapy, were included. Patients from two cancer centers treated between 12/2006 and 08/2019 were included in the data analysis. Results: Fifty-eight patients were enrolled in the study. The median age was 76.6 years [interquartile range (IQR): 71.6-83.4]. Thirty-nine patients were treated with concomitant chemoradiotherapy and 19 with a sequential strategy. The chemotherapy regimen consisted in a combination of platinum and taxanes. At a median follow-up of 52 months (IQR: 7-69), the 2-year progression-free survival (PFS) and overall survival (OS) were 35.5% and 66.9%, respectively. Male sex and a high Charlson index were identified as independent prognostic factors for worse OS. Acute grade 3-5 toxicities occurred in 34.4% of patients, including 1 grade 5 toxicity, and grade 3-4 late toxicities occurred in 17.2% of patients. In the whole cohort a high Charlson index was the only predictive factor for a higher risk of grade 3-5 acute toxicities (statistical trend in the concurrent cohort, P=0.06). Conclusions: The Charlson index correlated with toxicity and survival in elderly patients treated with chemoradiotherapy in locally advanced NSCLC. The addition of taxanes to platinum chemotherapy was safe in the present study and warrants further exploration.

Adipose tissue is associated with kidney function parameters.

Obesity is characterized by the accumulation of adipose tissue in different body compartments. Whether adipose tissue directly affects kidney function is still unknown. We aimed to investigate the role of the adipose tissue and circulating creatinine, cystatin C and kidney function in subjects free of cardio-renal diseases. In the KORA-MRI population-based study, 377 subjects (mean age 56.2 ± 9.2 years; 41.6% female) underwent whole-body 3T-MRI examination. Adipose tissue defined as visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were quantified from T1-DIXON sequence using a semi-automatic algorithm. Serum creatinine and cystatin C were measured using standard laboratory and estimated glomerular filtration rate (e-GFR) was performed based on creatinine (e-GFRcrea), cystatin C (e-GFRcys) and creatinine-cystatin C (e-GFRcc). Linear regression analysis, adjusted for risk factors, was used to investigate the relationship between adipose tissue and circulating creatinine, cystatin C, and kidney function. In multivariate analyses VAT was inversely associated with eGFRcys (ß = - 4.88, p = < 0.001), and positively associated with serum cystatin C (ß = 0.05, p = < 0.001), respectively. No association was found between other adipose parameters such as total adipose tissue (TAT) and subcutaneous adipose tissue (SAT) and serum creatinine, urine microalbumin and eGFRcrea. Stratified analyses according to BMI revealed confirmatory results for category of BMI > 30. VAT is positively associated with serum cystatin C and inversely with eGFR based on cystatin C, suggesting a direct involvement of visceral adipose tissue in increased metabolism of cystatin C and consequently decreased kidney function.

Trajectories of glycaemic traits exhibit sex-specific associations with hepatic iron and fat content: Results from the KORA-MRI study.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) represents a major disease burden in the population. While the bidirectional association between NAFLD and diabetes is established, little is known about the association of hepatic iron content and glycaemia. Moreover, analyses of sex-specific effects and of dynamic changes in glycaemia are scarce. METHODS: We investigated 7-year sex-specific trajectories of glycaemia and related traits (HbA1c, fasting glucose, fasting insulin, HOMA-IR, 2-h glucose and cross-sectional 2-h insulin) in a sample from a population-based cohort (N = 365; 41.1% female). Hepatic iron and fat content were assessed by 3T-Magnetic Resonance Imaging (MRI). Two-step multi-level models adjusted for glucose-lowering medication and confounders were applied. RESULTS: In women and men, markers of glucose metabolism correlated with hepatic iron and fat content. Deterioration of glycaemia was associated with increased hepatic iron content in men (normoglycaemia to prediabetes: beta = 2.21 s-1 , 95% CI [0.47, 3.95]). Additionally, deterioration of glycaemia (e.g. prediabetes to diabetes: 1.27 log(%), [0.84, 1.70]) and trajectories of glucose, insulin and HOMA-IR were significantly associated with hepatic fat content in men. Similarly, deterioration of glycaemia as well as trajectories of glucose, insulin and HOMA-IR was significantly associated with increased hepatic fat content in women (e.g. trajectory of fasting insulin: 0.63 log(%), [0.36, 0.90]). CONCLUSIONS: Unfavourable 7-year trajectories of markers of glucose metabolism are associated with increased hepatic fat content, particularly in women, whereas the association with hepatic iron content was less clear. Monitoring changes of glycaemia in the sub-diabetic range might enable early identification of hepatic iron overload and steatosis.

Interventional Management of Vascular Complications after Renal Transplantation. / Interventionelle Therapieoptionen vaskulärer Komplikationen nach Nierentransplantation.

BACKGROUND: Kidney transplantations are increasing due to demographic changes and are the treatment of choice for end-stage renal disease. Non-vascular and vascular complications may occur in the early phase after transplantation and at later stages. Overall postoperative complications after renal transplantations occur in approximately 12 % to 25 % of renal transplant patients. In these cases, minimally invasive therapeutic interventions are essential to ensure long-term graft function. This review article focuses on the most critical vascular complications after renal transplantation and highlights current recommendations for interventional treatment. METHOD: A literature search was performed in PubMed using the search terms "kidney transplantation", "complications", and "interventional treatment". Furthermore, the 2022 annual report of the German Foundation for Organ Donation and the EAU guidelines for kidney transplantation (European Association of Urology) were considered. RESULTS AND CONCLUSION: Image-guided interventional techniques are favorable compared with surgical revision and should be used primarily for the treatment of vascular complications. The most common vascular complications after renal transplantation are arterial stenoses (3 %-12.5 %), followed by arterial and venous thromboses (0.1 %-8.2 %) and dissection (0.1 %). Less frequently, arteriovenous fistulas or pseudoaneurysms occur. In these cases, minimally invasive interventions show a low complication rate and good technical and clinical results. Diagnosis, treatment, and follow-up should be performed in an interdisciplinary approach at highly specialized centers to ensure the preservation of graft function. Surgical revision should be considered only after exhausting minimally invasive therapeutic strategies. KEY POINTS: · Vascular complications after renal transplantation occur in 3 % to 15 % of patients.. · Image-guided interventional procedures should be performed primarily to treat vascular complications of renal transplantation.. · Minimally invasive interventions have a low complication rate with good technical and clinical outcomes.. CITATION FORMAT: · Verloh N, Doppler M, Hagar MT et al. Interventional Management of Vascular Complications after Renal Transplantation. Fortschr Röntgenstr 2023; 195: 495 - 504.

Quantification of Left Atrial Size and Function in Cardiac MR in Correlation to Non-Gated MR and Cardiovascular Risk Factors in Subjects without Cardiovascular Disease: A Population-Based Cohort Study.

Background: In magnetic resonance imaging (MRI), the comparability of gated and non-gated measurements of the left atrial (LA) area and function and their association with cardiovascular risk factors have not been firmly established. Methods: 3-Tesla MRIs were performed on 400 subjects enrolled in the KORA (Cooperative Health Research in the Augsburg Region) MRI study. The LA maximum and minimum sizes were segmented in gated CINE four-chamber sequences (LAmax and LAmin) and non-gated T1 VIBE-Dixon (NGLA). The area-based LA function was defined as LAaf = (LAmax − LAmin)/LAmax. Inter-and intra-reader reliability tests were performed (n = 31). Linear regression analyses were conducted to link LA size and function with cardiovascular risk factors. Results: Data from 378 subjects were included in the analysis (mean age: 56.3 years, 57.7 % male). The measurements were highly reproducible (all intraclass correlation coefficients ≥ 0.98). The average LAmax was 19.6 ± 4.5 cm2, LAmin 11.9 ± 3.5 cm2, NGLA 16.8 ± 4 cm2 and LAaf 40 ± 9%. In regression analysis, hypertension was significantly associated with larger gated LAmax (ß = 1.30), LAmin (ß = 1.07), and non-gated NGLA (ß = 0.94, all p ≤ 0.037). Increasing age was inversely associated with LAaf (ß = −1.93, p < 0.001). Conclusion: LA enlargement, as measured in gated and non-gated CMR is associated with hypertension, while the area-based LA function decreases with age.

Association between Large Arteries Diameter and Heart Function in Subjects Free of Cardiovascular Diseases.

To investigate the association between Aorta (Ao), pulmonary artery (PA) diameters and the PA/Ao ratio with right (RV) and left ventricle (LV) volumetric properties in subjects free of cardiovascular diseases. In the KORA-MRI study, 339 subjects (mean age 56.3 ± 9.1 years; 43.7% female) underwent whole-body 3T-MRI. Ao and PA were measured on DIXON sequences. Cvi42 quantified cardiac functional parameters from a SSFP sequence. The relationship between ascending (AAo), and descending aorta (DAo), as well as PA diameters, and RV and LV function were assessed using linear regression models adjusted for age, sex, and cardiovascular risk factors. AAo and DAo diameter were associated with LV end-diastolic volume (ß = 4.52, p = 0.015; ß = 7.1, p ≤ 0.001), LV end-systolic volume (ß = 2.37, p = 0.031; ß = 3.66, p = 0.002), while DAo associated with RV end-diastolic volume (ß = 6.45, p = 0.006) and RV end-systolic volume (ß = 3.9, p = 0.011). PA diameter was associated with LV end-diastolic volume (ß = 4.81, p = 0.003). Interestingly, the PA/Ao ratio was only associated with RV end-diastolic and end-systolic volume (ß = 4.48, p = 0.029; ß = 2.82, p = 0.037). Furthermore, we found different relationships between men and women. Ao and PA diameter were associated with LV and RV volumetric parameters in subjects free of cardiovascular diseases suggesting that ventricular volumetric performance directly relates to vascular diameter properties.

Association of MRI-based adrenal gland volume and impaired glucose metabolism in a population-based cohort study.

OBJECTIVES: The aim of this study was to assess adrenal gland volume by using magnetic resonance imaging (MRI) and to study its role as an indirect marker of impaired glucose metabolism and hypothalamic-pituitary-adrenal (HPA) axis activation in a population-based cohort. METHODS: Asymptomatic participants were enrolled in a nested case-control study and underwent a 3-T MRI, including T1w-VIBE-Dixon sequences. For the assessment of adrenal gland volume, adrenal glands were manually segmented in a blinded fashion. Impaired glucose metabolism was determined using fasting glucose and oral glucose tolerance test. Cardiometabolic risk factors were also obtained. Inter- and intrareader reliability as well as univariate and multivariate associations were derived. RESULTS: Among 375 subjects included in the analysis (58.5% male, 56.1 ± 9.1 years), 25.3% participants had prediabetes and 13.6% had type 2 diabetes (T2DM). Total adrenal gland volume was 11.2 ± 4.2 ml and differed significantly between impaired glucose metabolism and healthy controls with largest total adrenal gland volume in T2DM (healthy controls: 10.0 ± 3.9 ml, prediabetes: 12.5 ± 3.8 ml, T2DM: 13.9 ± 4.6 ml; p < 0.001). In the multivariate analysis, association of T2DM and increased adrenal gland volume was independent of age, sex, hypertension, triglycerides and body mass index (BMI), but was attenuated in subjects with prediabetes after adjustment for BMI. CONCLUSIONS: T2DM is significantly associated with increased adrenal gland volume by MRI in an asymptomatic cohort, independent of age, sex, dyslipidaemia, hypertension and BMI. Adrenal gland volume may represent an indirect marker of impaired glucose metabolism and HPA axis dysfunction.

Association between Adipose Tissue Depots and Dyslipidemia: The KORA-MRI Population-Based Study.

Obesity increases the risk of cardiovascular diseases (CVD), however, whether adipose tissue relates to dyslipidemia, and consequently to cardiovascular events remains unknown. Thus, we investigated the association of adipose tissue with circulating lipoproteins and triglycerides (TG) in subjects without CVD. 384 participants from the KORA-MRI study (mean age 56.2 ± 9.2 years; 41.9% female) underwent whole-body 3T-MRI. Visceral (VAT) and subcutaneous adipose tissue (SAT) derived from T1-DIXON-sequence using a semi-automatic algorithm. Total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and TG were measured. Linear regression was applied to examine the relationships between adipose tissue, circulating lipoproteins, and TG, adjusting for risk factors. VAT was associated with total cholesterol (per SD increase) (ß = 0.39, p < 0.001). Total adipose tissue (TAT) and VAT were inversely associated with HDL (ß = -0.09, p = 0.009; ß = -0.14, p < 0.001), and positively associated with LDL (ß = 0.32, p < 0.001; ß = 0.37, p < 0.001). All adipose tissues were associated with TG (ß = 0.20, p < 0.001; ß = 0.27, p < 0.001; ß = 0.11, p = 0.004). Stratified analysis by sex and body mass index (BMI) was confirmatory in women and in individuals with BMI < 30. Our results suggest that adipose tissue plays an important role in increasing CVD risk independent of BMI, whereas gender imbalance may be explained by accurate characterization and quantification of adipose tissue.

Distribution and Associated Factors of Hepatic Iron-A Population-Based Imaging Study.

Hepatic iron overload can cause severe organ damage; therefore, an early diagnosis and the identification of potential risk factors is crucial. We aimed to investigate the sex-specific distribution of hepatic iron content (HIC) in a population-based cohort and identify relevant associated factors from a panel of markers. We analyzed N = 353 participants from a cross-sectional sample (KORA FF4) who underwent whole-body magnetic resonance imaging. HIC was assessed by single-voxel spectroscopy with a high-speed T2-corrected multi-echo technique. A large panel of markers, including anthropometric, genetic, and laboratory values, as well as behavioral risk factors were assessed. Relevant factors associated with HIC were identified by variable selection based on LASSO regression with bootstrap resampling. HIC in the study sample (mean age at examination: 56.0 years, 58.4% men) was significantly lower in women (mean ± SD: 39.2 ± 4.1 s-1) than in men (41.8 ± 4.7 s-1, p < 0.001). Relevant factors associated with HIC were HbA1c as well as prediabetes for men and visceral adipose tissue as well as age for women. Hepatic fat, alcohol consumption, and genetic risk score for iron levels were associated with HIC in both sexes. In conclusion, there are sex-specific associations of HIC with markers of body composition, glucose metabolism, and alcohol consumption.

Subclinical cardiac impairment relates to traditional pulmonary function test parameters and lung volume as derived from whole-body MRI in a population-based cohort study.

To evaluate the relationship of cardiac function, including time-volume-curves, with lung volumes derived from pulmonary function tests (PFT) and MRI in subjects without cardiovascular diseases. 216 subjects underwent whole-body MRI and spirometry as part of the KORA-FF4 cohort study. Lung volumes derived semi-automatically using an in-house algorithm. Forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and residual volume were measured. Cardiac parameters derived from Cine-SSFP-sequence using cvi42, while left ventricle (LV) time-volume-curves were evaluated using pyHeart. Linear regression analyses assessed the relationships of cardiac parameters with PFT and MRI-based lung volumes. Mean age was 56.3 ± 9.2 years (57% males). LV and right ventricular (RV) end-diastolic-, end-systolic-, stroke volume, LV peak ejection- and early/late diastolic filling rate were associated with FEV1, FVC, and residual volume (excluding late diastolic filling rate with FEV1, LV end-systolic/stroke volume and RV end-diastolic/end-systolic volumes with residual volume). In contrast, LV end-diastolic volume (ß = - 0.14, p = 0.01), early diastolic filling rate (ß = - 0.11, p = 0.04), and LV/RV stroke volume (ß = - 0.14, p = 0.01; ß = - 0.11, p = 0.01) were inversely associated with MRI-based lung volume. Subclinical cardiac impairment was associated with reduced FEV1, FVC, and residual volume. Cardiac parameters decreased with increasing MRI-based lung volume contrasting the results of PFT.

Dietary habits and the presence and degree of asymptomatic diverticular disease by magnetic resonance imaging in a Western population: a population-based cohort study.

BACKGROUND: Despite the worldwide burden of diverticular disease, the connections between diverticular disease and dietary habits remain poorly understood, particularly in an asymptomatic representative sample. We investigated the association between asymptomatic diverticular disease as assessed by magnetic resonance imaging (MRI) and dietary habits in a Western study cohort. METHODS: Participants from a cross-sectional sample of a population-based cohort study underwent whole-body 3T-MRI including an isotropic VIBE-Dixon sequence. The presence and extent of diverticular disease was assessed in blinded fashion. Habitual dietary intake was recorded using a blended approach, applying 24-h food lists and a food-frequency questionnaire. Traditional cardiometabolic risk factors were obtained by interviews and medical examination. Univariate and multivariate associations were calculated. RESULTS: A total of 308 subjects were included in this analysis (56% male, 56.4 ± 9.1 years). 39.9% had any form of diverticular disease and 15.3% had advanced asymptomatic diverticular disease. After adjustment for age, sex and total energy intake a higher intake of fiber and vegetables was associated with a lower odds for asymptomatic diverticular disease (fiber: OR 0.68 95% CI [0.48, 0.95]; vegetables: OR 0.72 95% CI [0.53, 0.97]) and an increased intake of meat was associated with an approximately two-fold higher odds for advanced asymptomatic diverticular disease (OR 1.84 95% CI [1.13, 2.99]). However, after additional adjustment for body-mass-index (BMI), alcohol consumption, smoking behavior and physical activity only a high fiber and vegetables intake remained significantly associated with lower odds of asymptomatic diverticular disease. CONCLUSION: Our results indicate that a high-fiber diet and increased intake of vegetables is associated with lower odds of having asymptomatic diverticular disease, independent of age, sex, total energy intake, BMI and other life-style factors.

Association of Habitual Dietary Intake with Liver Iron-A Population-Based Imaging Study.

Iron-related disorders of the liver can result in serious health conditions, such as liver cirrhosis. Evidence on the role of modifiable lifestyle factors like nutrition in liver iron storage is lacking. Thus, we aimed to assess the association of habitual diet with liver iron content (LIC). We investigated 303 participants from the population-based KORA-MRI study who underwent whole-body magnetic resonance imaging (MRI). Dietary habits were evaluated using repeated 24 h food lists and a food frequency questionnaire. Sex-stratified multiple linear regression models were applied to quantify the association between nutrition variables of interest and LIC, adjusting for liver fat content (LFC), energy intake, and age. Mean age of participants was 56.4 ± 9.0 years and 44.2% were female. Mean LIC was 1.23 ± 0.12 mg/g dry weight, with higher values in men than in women (1.26 ± 0.13 and 1.20 ± 0.10 mg/g, p < 0.001). Alcohol intake was positively associated with LIC (men: ß = 1.94; women: ß = 4.98, p-values < 0.03). Significant negative associations with LIC were found for fiber (ß = -5.61, p < 0.001) and potassium (ß = -0.058, p = 0.034) for female participants only. Furthermore, LIC was highly correlated with liver fat content in both sexes. Our findings suggests that there are sex-specific associations of habitual dietary intake and LIC. Alcohol, fiber, and potassium may play a considerable role in liver iron metabolism.

Automated MR-based lung volume segmentation in population-based whole-body MR imaging: correlation with clinical characteristics, pulmonary function testing and obstructive lung disease.

OBJECTIVES: Whole-body MR imaging is increasingly utilised; although for lung dedicated sequences are often not included, the chest is typically imaged. Our objective was to determine the clinical utility of lung volumes derived from non-dedicated MRI sequences in the population-based KORA-FF4 cohort study. METHODS: 400 subjects (56.4 ± 9.2 years, 57.6% males) underwent whole-body MRI including a coronal T1-DIXON-VIBE sequence in inspiration breath-hold, originally acquired for fat quantification. Based on MRI, lung volumes were derived using an automated framework and related to common predictors, pulmonary function tests (PFT; spirometry and pulmonary gas exchange, n = 214) and obstructive lung disease. RESULTS: MRI-based lung volume was 4.0 ± 1.1 L, which was 64.8 ± 14.9% of predicted total lung capacity (TLC) and 124.4 ± 27.9% of functional residual capacity. In multivariate analysis, it was positively associated with age, male, current smoking and height. Among PFT indices, MRI-based lung volume correlated best with TLC, alveolar volume and residual volume (RV; r = 0.57 each), while it was negatively correlated to FEV1/FVC (r = 0.36) and transfer factor for carbon monoxide (r = 0.16). Combining the strongest PFT parameters, RV and FEV1/FVC remained independently and incrementally associated with MRI-based lung volume (ß = 0.50, p = 0.04 and ß = - 0.02, p = 0.02, respectively) explaining 32% of the variability. For the identification of subjects with obstructive lung disease, height-indexed MRI-based lung volume yielded an AUC of 0.673-0.654. CONCLUSION: Lung volume derived from non-dedicated whole-body MRI is independently associated with RV and FEV1/FVC. Furthermore, its moderate accuracy for obstructive lung disease indicates that it may be a promising tool to assess pulmonary health in whole-body imaging when PFT is not available. KEY POINTS: • Although whole-body MRI often does not include dedicated lung sequences, lung volume can be automatically derived using dedicated segmentation algorithms • Lung volume derived from whole-body MRI correlates with typical predictors and risk factors of respiratory function including smoking and represents about 65% of total lung capacity and 125% of the functional residual capacity • Lung volume derived from whole-body MRI is independently associated with residual volume and the ratio of forced expiratory volume in 1 s to forced vital capacity and may allow detection of obstructive lung disease.