Pulmonary ventilation imaging in asthma and cystic fibrosis using oxygen-enhanced 3D radial ultrashort echo time MRI

Background

A previous study demonstrated the feasibility of using 3D radial ultrashort echo time (UTE) oxygen-enhanced MRI (UTE OE-MRI) for functional imaging of healthy human lungs. The repeatability of quantitative measures from UTE OE-MRI needs to be established prior to its application in clinical research.

Purpose

To evaluate repeatability of obstructive patterns in asthma and cystic fibrosis (CF) with UTE OE-MRI with isotropic spatial resolution and full chest coverage.

Study Type

Volunteer and patient repeatability.

Population

Eighteen human subjects (five asthma, six CF, and seven normal subjects).

Field Strength/Sequence

Respiratory-gated free-breathing 3D radial UTE (80 μs) sequence at 1.5T.

Assessment

Two 3D radial UTE volumes were acquired sequentially under normoxic and hyperoxic conditions. A subset of subjects underwent repeat acquisitions on either the same day or ≤15 days apart. Asthma and CF subjects also underwent spirometry. A workflow including deformable registration and retrospective lung density correction was used to compute 3D isotropic percent signal enhancement (PSE) maps. Median PSE (MPSE) and ventilation defect percent (VDP) of the lung were measured from the PSE map.

Statistical Tests

The relations between MPSE, VDP, and spirometric measures were assessed using Spearman correlations. The test–retest repeatability was evaluated using Bland–Altman analysis and intraclass correlation coefficients (ICC).

Results

Ventilation measures in normal subjects (MPSE = 8.0%, VDP = 3.3%) were significantly different from those in asthma (MPSE = 6.0%, P = 0.042; VDP = 21.7%, P = 0.018) and CF group (MPSE = 4.5%, P = 0.0006; VDP = 27.2%, P = 0.002). MPSE correlated significantly with forced expiratory lung volume in 1 second percent predicted (ρ = 0.72, P = 0.017). The ICC of the test–retest VDP and MPSE were both ≥0.90. In all subject groups, an anterior/posterior gradient was observed with higher MPSE and lower VDP in the posterior compared to anterior regions (P ≤ 0.0021 for all comparisons).

Data Conclusion

3D radial UTE OE-MRI supports quantitative differentiation of diseased vs. healthy lungs using either whole lung VDP or MPSE with excellent test–retest repeatability.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2017.

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Correlation between glycolytic activity on [18F]-FDG-PET and cell density on diffusion-weighted MRI in lymphoma at staging

Background

[18F]-FDG-PET/MR carries a high diagnostic value in whole-body oncologic imaging and allows simultaneous quantitative measurements of glucose metabolism (SUV) and cell density (ADC).

Purpose

To determine the relationship between SUV and ADC values extracted from simultaneously acquired [18F]-FDG-PET/MR data of patients with FDG-avid lymphomas at staging.

Study Type

Prospective.

Population

Patients with histologically proven lymphoma referred for staging.

Field Strength/Sequences

Hybrid PET/MR device (3T); axial, two-point Dixon, 3D, volume-interpolated, T₁-weighted breath-hold sequence; coronal T₂-weighted half-Fourier acquisition single-shot turbo spin-echo. Single-shot, echo-planar imaging-based, spectral adiabatic inversion recovery diffusion-weighted imaging.

Assessment

Staging was performed according to the modified Ann Arbor system by a board-certified radiologist and a board-certified nuclear medicine physician, blinded to the clinical and histological information, in consensus. SUVs and ADCs values were collected, for each positive nodal and extranodal region, from the lesion demonstrating the largest diameter.

Statistical Tests

Descriptive data included absolute frequencies and percentages for categorical data, and arithmetic means and 95% confidence intervals for scale-type data. The Pearson correlation coefficient was used to assess the relationship between SUVs and ADCs (P ≤ 0.05). Additional separate analyses were performed according to histological lymphoma subtype, for nodal and extranodal lesions and excluding bone lesions.

Results

Overall, 100 patients were examined (55 males, 45 females; age ± SD in years, 51.6 ± 19.5). Histology revealed Hodgkin-lymphoma and non-Hodgkin-lymphoma in 26 and 74 patients, respectively. Twenty patients were stage I, 21 stage II, 24 stage III, and 31 stage IV on [18F]-FDG-PET/MR (ie, four patients negative at imaging). Based on 391 lesions (ie, 367 excluding bone lesions) no significant correlations between SUVmax and ADCmin, or between SUVmean and ADCmean, emerged (respectively, r = 0.091, P = 0.073, 95% CI [–0.01, 0.19] and r = –0.032, P = 0.527, 95% CI [–0.13, 0.07] including bone lesions; r = 0.06, P = 0.21, 95% CI [–0.04, 0.17] and r = –0.05, P = 0.32, 95% CI [–0.15, 0.05] excluding bone lesions). A significant correlation was observed only between ADCmean and SUVmean for follicular lymphoma (r = −0.33, P = 0.001).

Data Conclusion

SUVs and ADCs were demonstrated to be independent biomarkers in lymphomas. A moderate correlation between SUVs and ADCs likely is present in follicular lymphoma.

Level of Evidence: 1

Technical Efficacy: Stage 3

J. Magn. Reson. Imaging 2017.

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Liver volume as a predictor of functional improvement post DAA treatment

Background New direct antiviral agents (DAA) for HCV treatment result in sustained viral response (SVR) in most patients. However, predicting the point of no-return is still an unmet need for those with advanced liver disease. Aim to assess if baseline liver volume is a predictor of post-SVR liver function. Methods Cirrhotic patients assessed for liver transplantation (LT) and consecutively treated with DAA between September 2014 and 2015 who achieved an SVR were included. Pretreatment liver (LV) and spleen (SV) volumes adjusted by Body Surface Area (BSA) were calculated from CT/MR images. Liver function was assessed by Child-Turcotte-Pugh (CTP) and MELD scores and a multivariate mixed regression model was used to identify baseline factors associated with improvement of liver function overtime. Results We included 42 patients with a median age of 58.6 years (Q1-Q3: 52.7 - 68.8); MELD, 14 (11-17); CTP, 9 (8-10); LV, 1400.9 mL (1183.2-1601.4); SV, 782.9 mL (490.6-1118.8). MELD scores at baseline and at last control were 14 (11-17) and 10 (8-12), respectively (p

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Brain Integrity Changes underlying Cognitive and Functional Recovery Postliver Transplant Continue to Evolve Over 1 Year

Abstract: Background There is evidence of brain recovery on brain MRI early postliver transplant(LT) but the longer-term impact is unclear. Aim of this study was to determine the change in brain MRI parameters, cognition and health-related quality of life (HRQOL) between 6 and 12 months post-LT. Methods Listed cirrhotics underwent cognitive, HRQOL and brain MRI pre, 6 months (post-LT1) and 1-year (post-LT2) post-LT. Assessment of MRI changes between visits was performed for ammonia-associated metabolite changes using spectroscopy (MRS), white matter changes using Tract-based Spatial Statistics (TBSS) analysis on Diffusion Tensor Imaging (DTI) data and grey matter changes using Voxel-based morphometry (VBM) analysis on 3D high resolution T1-weighted images. Results Forty-five patients were included of which, twenty-three were tested at all visits. Cognitive and HRQOL scores improved between all visits compared to pre-LT values. This trend continued on MRS with reduced glutamine+glutamate(Glx) and higher myoinositol(mI), Choline(Cho) between pre-LT/post-LT1 but lower degrees of improvement between post-LT1/post-LT2. On DTI, mean-diffusivity(MD), linear-diffusivity(LD) and mode of anisotropy(MO) continued to increase in the posterior internal capsule at both post-LT visits. On VBM, a continued increase was seen in basal ganglia grey matter between both post-LT visits was seen. Conclusions HRQOL and cognition continue to improve compared to pre-LT values up to 1 year post-LT, although the rate of improvement slows down after 6 months. Grey matter increase is steady over time at 1 year although changes in ammonia-related metabolites and white matter integrity improve at a slower pace at 1 year post-LT. Corresponding Author: Jasmohan S Bajaj, MD, MS, Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, 1201 Broad Rock Boulevard, Richmond, VA, 23221, USA, Phone: (804) 675-5802, Fax: (804) 675 5816. Email: jasmohan.bajaj@vcuhealth.org Author contributions: JSB, VA, JS, FGM, JBW were involved in research design, performance of the research and data analysis, MBW, HSG, DMH, MF, EAG, AF, RKS, RTS, PP, AJS, MSS, SM, VL were involved in performance of the research, LRT was involved in data analysis, All authors participated in the writing of the paper. Funding: Partly supported by NIH RO1DK089713 and VA Merit Review 1I0CX001076 to JSB Disclosure: The authors declare no conflicts of interest Presentation: Portions of this study were presented as an oral presentation at the EASL conference in Amsterdam 2017. Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Asthma, hay fever and eczema share more than 100 genetic risk factors

Researchers at Karolinska Institutet have contributed to a major international study in Nature Genetics that has identified more than 100 genetic risk factors for asthma, hay fever and eczema which explain why these conditions often coexist. Asthma, hay fever and eczema are allergic conditions that affect different parts of the body: the lung, the nose and the skin. Previous studies have shown that the three conditions share many genetic risk factors, but it has not been known exactly where in the genome those shared genetic risk factors are located. The new international study, led by researchers at QIMR Berghofer Medical Research Institute, Australia, aimed to determine which genes are involved in all three conditions by looking at data from the Swedish Twin Registry and analysing the genomes of more than 360,000 individuals. The researchers pinpointed 136 separate positions in the genome that are risk factors for developing these conditions by influencing whether nearby genes are switched on or off. They believe that these genes in turn influence the risk of asthma, hay fever and eczema by affecting how the cells of the immune system work. Environmental factors affect the genes The study also found that environmental factors affect whether many of these genes are switched on or off. For example, the researchers found one gene that is more likely to be switched off in people who smoke. When the gene is switched off, the risk of developing allergies increases. The mapping of genetic risk factors helps us understand why asthma, hay fever and eczema often coexist and provides new clues on how these conditions can be prevented or treated, according to co-author Catarina Almqvist Malmros, Professor at Karolinska Institutet's Department of Medical Epidemiology and Biostatistics. The study involved collaborators from Australia, Germany, the Netherlands, Norway, Sweden, the UK and the US and was supported by the Australian National Health and Medical Research Council (NHMRC), The Swedish Research Council and the Swedish Heart-Lung Foundation, among others. This news article is based on a press release from QIMR Berghofer Medical Research Institute. Publication "Shared genetic origin of asthma, hay fever and eczema elucidates allergic disease biology" Manuel A Ferreira , Judith M Vonk, Hansjörg Baurecht, Ingo Marenholz, Chao Tian, Joshua D Hoffman, Quinta Helmer, Annika Tillander, Vilhelmina Ullemar, Jenny van Dongen, Yi Lu, Franz Rüschendorf, Jorge Esparza-Gordillo, Chris W Medway, Edward Mountjoy, Kimberley Burrows, Oliver Hummel, Sarah Grosche, Ben M Brumpton, John S Witte, Jouke-Jan Hottenga, Gonneke Willemsen, Jie Zheng, Elke Rodríguez, Melanie Hotze, Andre Franke, Joana A Revez, Jonathan Beesley, Melanie C Matheson, Shyamali C Dharmage, Lisa M Bain, Lars G Fritsche, Maiken E Gabrielsen, Brunilda Balliu, The 23andMe Research Team, AAGC collaborators, BIOS consortium, LifeLines Cohort Study, Jonas B Nielsen, Wei Zhou, Kristian Hveem, Arnulf Langhammer, Oddgeir L Holmen, Mari Løset, Gonçalo R Abecasis, Cristen J Willer, Andreas Arnold, Georg Homuth, Carsten O Schmidt, Philip J Thompson, Nicholas G Martin, David L Duffy, Natalija Novak, Holger Schulz, Stefan Karrasch, Christian Gieger, Konstantin Strauch, Ronald B Melles, David A Hinds, Norbert Hübner, Stephan Weidinger, Patrik K E Magnusson, Rick Jansen, Eric Jorgenson, Young-Ae Lee, Dorret I Boomsma, Catarina Almqvist, Robert Karlsson, Gerard H Koppelman & Lavinia Paternoster. Nature Genetics, online 30 October 2017, doi:10.1038/ng.3985

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Regarding CEPN’s opinion on suspected misconduct in research

Comment: The Central Ethical Review Board's Expert Group for Misconduct in Research has now submitted its opinion to Karolinska Institutet regarding six articles of which Paolo Macchiarini is the main author. In June 2016, Karolinska Institutet requested that CEPN express its opinion in order to investigate suspected misconduct in research. The authors of the articles will now also be invited to give their opinions before the vice-chancellor of Karolinska Institutet reaches a decision on the matter. At the present time, it is not possible to state the date on which this decision will be made.

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KI researchers receive SEK 11 million from AFA Insurance

Four researchers at Karolinska Institutet will share SEK 11 million in research grants from AFA Insurance. Their research will contribute to reducing work-related injuries and long-term sick leave. Magnus Helgesson, Department of Clinical Neuroscience, will receive SEK 4,200,000 to study the role played by a combination of physical and psychosocial burdens on sick leave among employees in health and social care. The study will make it possible to identify how risk factors and determinants of health affect employees' sickness-related absenteeism. Sara Gunnare, Institute of Environmental Medicine, will receive SEK 2,878,000 to map the health of eyelash stylists and nail technologists, their working environments and knowledge of protective equipment. She will also measure exposure to acrylates contained in the products used by these professional groups, which can cause respiratory problems and eczema. Annika Lindahl Norberg, Institute of Environmental Medicine, will receive SEK 2,229,000 to investigate which work-environment factors affect the desire of nurses and midwives to remain in a position requiring night work. The study is intended to increase knowledge about how night and shift work can be combined with good health, high levels of motivation and dedication to the job. Anneli Julander, Institute of Environmental Medicine, will receive SEK 2,116,000 to map the effects of short-term and repeated skin contact with nickle in professions where exposure is not considered high. Previous research has carried out on professions exposed to high levels of nickle but knowledge is lacking regarding the effects of more diffuse daily contact.

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