Research Presentation Session: Chest

RPS 304 - MRI in thoracic imaging

February 28, 11:30 - 12:30 CET

7 min
Elexacaftor/Tezacaftor/Ivacaftor improves bronchial artery dilatation detected by magnetic resonance imaging in patients with cystic fibrosis
Lena Wucherpfennig, Heidelberg / Germany
Author Block: L. Wucherpfennig1, S. Wege1, H-U. Kauczor1, C. P. Heussel1, O. Sommerburg1, M. Stahl2, M. Mall2, M. Eichinger1, M. Wielpütz1; 1Heidelberg/DE, 2Berlin/DE
Purpose: It was previously shown that magnetic resonance imaging (MRI) detects improvements in mucus plugging and bronchial wall thickening, but not lung perfusion in patients with cystic fibrosis (CF) treated with elexacaftor/tezacaftor/ivacaftor (ETI). It is still unclear, whether bronchial artery dilatation (BAD), a key feature of advanced lung disease, indicates irreversibility of perfusion abnormalities and whether BAD could be reversed in CF patients treated with ETI.
Methods or Background: 59 adults with CF underwent longitudinal chest MRI including MR angiography (MRA) twice, 35 CF patients (mean age 31±7 years) before (MRI1) and after (MRI2) at least one month (mean duration 8±4 months) on ETI therapy and 24 control CF patients (mean age 31±7 years) without ETI. MRI was assessed using the validated chest MRI score, and presence and total lumen area of BAD were assessed with commercial software.
Results or Findings: The MRI global score was stable in the control group from MRI1 to MRI 2 (mean difference: 1.1±3.4, P=0.054), and was reduced in the ETI group (-10.1±4.2, P<0.001). In the control as well as in the ETI group, BAD was present in almost all patients at baseline (95% and 94%, respectively) and presence did not change at MRI2. The BAD total lumen area was stable in the control group from MRI1 to MRI2 (mean difference: 1.0±3.0 mm2, P=0.099), but decreased in the ETI group (-6.6±5.8 mm2, P<0.001). This decrease correlated with improvements in the MRI global score (r=0.540, P<0.001).
Conclusion: Our data show that BAD may be partially reversible under ETI therapy in adult CF patients with established disease.
Limitations: The number of patients treated with ETI was only moderate. Moreover, our study was conducted in adults with CF, excluding children with milder lung disease.
Funding for this study: This study was supported by grants from the German Federal Ministry of Education and Research (82DZL00401, 82DZL004A1, 82DZL009B1), the German Research Foundation (STA 1685/1-1 to M.S.) and the Mukoviszidose e.V. (S02/09, C-H-P 1504). Funders had no involvement in the collection, analysis and interpretation of data, in the writing of the report and in the decision to submit the article for publication.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the ethics committee of Heidelberg Medical Faculty.
7 min
Magnetic resonance imaging detects delayed perfusion inside perfusion defects in patients with cystic fibrosis
Patricia Leutz-Schmidt, Heidelberg / Germany
Author Block: P. Leutz-Schmidt1, J. Grolig1, S. Triphan1, M. Mall1, O. Sommerburg1, A. Koeppe1, B. Nestler2, H-U. Kauczor1, M. Wielpütz1; 1Heidelberg/DE, 2Karlsruhe/DE
Purpose: Dynamic contrast-enhanced perfusion MRI (DCE-MRI) detects perfusion abnormalities in patients with cystic fibrosis (CF) from preschool age related to a reduction in inflow through pulmonary arteries. However, little is known about the alterations of bronchial arterial inflow from the systemic circulation. We hypothesised that in perfusion defect areas a delayed perfusion from bronchial arteries may be observed related to bronchial artery dilatation (BAD).
Methods or Background: Morpho-functional MRI incl. DCE-MRI from 75 patients with CF (mean age 15.3±5.5 years, range 6-29 years) were included. The lungs were segmented on coronal 3D T1 and registered onto DCE-MRI. The arterial input function (AIF) was calculated automatically, in order to quantify pulmonary blood flow (PBF) and mean transit time (MTT). Perfusion defects were classified in percent (QDP). Quantitative perfusion parameters were compared in areas with normal perfusion vs perfusion defects.
Results or Findings: Mean QDP was 35.4±23.0%. Mean PBF was 165.2±90.4 ml/100 ml per minute in normal vs 56.9±24.2 ml/100ml per minute in perfusion defect areas (P<0.001). Corresponding MTT was 5.4±1.7 seconds in normal vs 6.9±2.2 seconds in defect areas (P<0.001). 48 CF patients had BAD, and 27 did not show BAD on DCE-MRI. Patients with BAD had higher QDP (46.2±21.3 vs 16.1±9.0, P<0.001), lower PBF (91.9±54.8 vs 178.3±77.4, P<0.001) and tended to have shorter MTT (5.5±1.2 vs 6.2±2.2, P<0.06) for the whole lung. Considering defect areas only, MTT was shorter in patients with BAD vs without (6.3s ±1.8s vs 8.1s ± 2.6s, P<0.001).
Conclusion: Lung areas with perfusion defects in the pulmonary arterial phase show delayed perfusion in the systemic arterial phase in patients with CF. Patients with BAD have more severe perfusion defects and reduced PBF. Increased inflow through BAD can potentially be quantified by MTT.
Limitations: Ground truth is missing for the validation of quantitative perfusion results.
Funding for this study: This study was funded by the German Center for Lung research (DZL)
This study was supported by grants from the German Federal Ministry of Education and Research (BMBF) (82DZL004A1).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by an ethics committee; the vote number is S-211/2011.
7 min
Delta-radiomics features of ADC maps as early predictors of treatment response in lung cancer
Christian Marcel Heidt, Heidelberg / Germany
Author Block: C. M. Heidt1, J. Bohn1, O. von Stackelberg1, O. Weinheimer1, J. Vogel-Claussen2, F. L. Giesel3, H-U. Kauczor1, C. P. Heußel1, G. Heußel1; 1Heidelberg/DE, 2Hannover/DE, 3Düsseldorf/DE
Purpose: The purpose of this study was to investigate the feasibility of detecting very early treatment-induced tumour tissue changes in patients with advanced lung adenocarcinoma using diffusion-weighted MRI-derived radiomics features.
Methods or Background: This prospective study included 144 patients receiving TKI (n=64) or chemotherapy (n=80) for lung adenocarcinoma. Patients underwent diffusion-weighted MRI at baseline as well as +1, +7 and +14 days after treatment initiation. Radiomics features quantifying shape, textures and intensities were extracted from tumour ROI segmentations and feature changes over time were analysed for correlation with treatment response (TR) according to RECIST and progression-free survival (PFS).
Results or Findings: Out of 14 selected delta-radiomics features, 6 showed significant correlations with PFS or TR. Most significant correlations were found after 14 days. Features quantifying ROI heterogeneity, such as short run emphasis (P = 0.037 (pfs) / 0.006 (tr)), gradient short run emphasis (P = 0.058 (pfs) / 0.012 (tr)) and zone percentage (P = 0.019 (pfs) / 0.013 (tr)) increased in patients with overall better TR. Patients with worse overall response and survival instead showed an increase in features quantifying ROI homogeneity, such as normalised inverse difference (P = 0.012 (pfs)/ 0.043 (tr)). Clustering of these imaging features allows stratification of patients into groups of longer and shorter survival.
Conclusion: As early as 2 weeks after initiation of treatment, diffusion MRI of lung adenocarcinoma reveals quantifiable tissue-level insights that correlate well with future treatment (non-)response. Diffusion MRI derived radiomics thus shows promise as an early, radiation-free decision-support to assess efficacy and potentially alter treatment course early.
Limitations: The study was performed on a small, single-centre data set, pending validation on external data.
Funding for this study: Funding was provided by the German Center for Lung Research (FKZ 82DZLF14A2).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Approval was granted by Heidelberg Medical School Ethics committee Ethics Vote S-445/2015.
7 min
3.0T MRI with functional sequences and respiratory motion-resolved compressed sensing reconstruction of free-breathing radial acquisition for immediate response assessment of lung tumour postablation
Danyang Zhao, Shanghai / China
Author Block: D. Zhao, L. Liu, X. Ye, k. liu, C. Yiheng, S. Yuanxin, F. Wang, H. Sun; Shanghai/CN
Purpose: The purpose of this study was to use serial magnetic resonance imaging (MRI) examinations to observe changes in malignant lung tumours within a short time postablation.
Methods or Background: Patients with primary or metastatic lung tumours eligible for ablation were included in this study. Ablation was performed according to standard procedures. Unenhanced and dynamic contrast-enhanced MRI scans were performed preablation and in one week after ablation. Dynamic imaging were undergone with free-breathing imaging technique combining compressed sensing (CS) and parallel imaging with golden-angle radial sampling instead of conventional breath-hold volumetric interpolated breath-hold examination (VIBE) or liver acquisition volume acceleration (LAVA). At each time point, the signal intensity and parameters of the ablation zone in both perfusion imaging and DCE imaging were examined and analysed.
Results or Findings: Using CS technique we obtained T1-weighted imaging with high spatial resolution without requiring patients to hold their breath. A total of 19 nodules in 17 patients were included in the study. Among them, 16 nodules examined parameters of IVIM. The ablation zone in MRI imaging has been shown to have a central area with complete tissue necrosis showed no enhancement (19/19) on ceT1. The value of Ktrans (18/19), D*(10/16), iAUC90(19/19), CER(19/19) were significantly lower in the postablation zone compared to the preablation tumour, which represents decreased blood flow perfusion. The increase in D value (11/16) and ADC value (13/16) indicates that the diffusion of water molecules is less restricted compared to before.
Conclusion: Patients who cannot hold their breath autonomously can get high-quality images and stable parameter data by CS technique. The ablative margin and the changes of tumour activity and microvascular perfusion can be analysed via functional MRI images, which can be used to assess immediate response with technical success and ablative margin.
Limitations: The limitations of the study are the lack of cases and long-term follow-up data.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: The study is retrospective.
7 min
Feasibility of pulmonary MRI for lung nodule detection and quantification using AI-accelerated 3D gradient echo imaging
Alexander Wolfgang Marka, Munich / Germany
Author Block: A. W. Marka1, M. Steinhardt1, M. Graf1, A. Sauter1, K. Weiss2, M. Makowski1, D. C. Karampinos1, J. Gawlitza1, S. Ziegelmayer1; 1Munich/DE, 2Hamburg/DE
Purpose: Pulmonary MR imaging has made substantial progress in detecting lung nodules through optimisation and developing new sequences in recent years. Nevertheless, the widespread integration of MRI as an alternative method in lung cancer screening is limited either by long scan times or insufficient signal-to-noise ratio.
Methods or Background: In this prospective trial, patients with benign and malignant lung nodules admitted between December 2021 and December 2022 underwent low-dose chest CT and pulmonary MRI using a 3D gradient echo sequence, accelerated with a combination of parallel imaging, compressed sensing, and deep learning. 3D segmentation masks of 192 lung nodules were created in both modalities, and quantitative morphological features were extracted from the segmentation masks. Two readers evaluated all cases in a blinded setting and measured the most extensive lesion. The agreement and relationship between all features in both modalities were assessed.
Results or Findings: A total of 38 patients (mean [SD] age, 65±13 years; 19 women [50%]) with 192 pulmonary nodules were included and analysed. The average scan time was 2.5 minutes. The quantitative features showed a strong positive relationship between both modalities (maximum nodule diameter (r = 0.99 95% CI [0.95, 1.02]), surface-area (r = 1.00 95% CI [0.96, 1.04]), nodule volume (r = 1.00 CI [0.96, 1.04]). Mean differences in maximum diameter were 0.1 mm with a 95% CI of 2.09 mm and -1.89 mm. Nodule diameter measurements for the MR sequence showed excellent interrater agreement.
Conclusion: Pulmonary MRI with an accelerated 3D gradient echo sequence showed comparable quantitative measurements to low-dose CT. The average examination time of 2.5 minutes is a relevant factor for applying MRI in lung cancer screening as an alternative screening method.
Limitations: Our study included only 38 subjects with a consequently limited range of pathologies.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the ethics committee of Technical University of Munich School of Medicine.
7 min
Conjugate gradient reconstruction for pulmonary thin-section MRI with ultra-short TE: capability for acquisition time reduction while maintaining image quality and nodule detection
Yoshiharu Ohno, Toyoake / Japan
Author Block: Y. Ohno1, K. Yamamoto2, M. Ikedo2, M. Yui2, M. Shinohara2, Y. Sano2, H. Nagata1, T. Ueda1, Y. Ozawa1; 1Toyoake/JP, 2Otawara/JP
Purpose: The purpose of this study was to compare the capability of conjugate gradient reconstruction (CG-Recon) for acquisition time reduction, image quality and nodule detection performance with conventional grid reconstruction (Grid-Recon) on pulmonary thin-section MRI with ultra-short TE (UTE-MRI) at in vitro and in vivo studies.
Methods or Background: Firstly, a commercially available NEMA phantom was scanned by UTE-MRI sequence under reduction of sampling spoke numbers as follows: original (n=1: UTEoriginal), 1/2 (UTE1/2), 1/4 (UTE1/4) and 1/6 (UTE1/6). Then, each piece UTE-MRI data was reconstructed using both methods. Secondly, 40 patients with lung nodule underwent thin-section CT and UTE-MRI by same sequences, and all UTE-MRI data were also reconstructed with each method. To determine the influence of spoke number reduction and reconstruction method on quantitative image quality at in vitro study, full width at half maximum (FWHM) of phantoms was assessed. At in vivo study, lung signal-to-noise ratio (SNR), overall image quality, artifact and probability for nodule presence were assessed by ROI measurement or 5-point scales. FWHM and SNR were compared among all UTE-MR data by Tukey's HSD test. All qualitative indexes were compared among all UTE-MR data by Wilcoxon's signed rank test.
Results or Findings: FWHM, SNR overall image quality and nodule detection probability of each UTEoriginal and UTE1/2 with CG-Recon were significantly better than those of others (P<0.05). Artifact of each UTEoriginal and UTE1/2 with CG-Recon were significantly lower than those of others (P<0.05).
Conclusion: Conjugate gradient reconstruction is useful for reducing acquisition time while maintaining image quality and nodule detection performance on pulmonary thin-section MRI with UTE.
Limitations: This was a single centre study with a limited study population.
Funding for this study: A research grant was received from Canon Medical Systems Corporation.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the IRB of Fujita Health University Hospital.
7 min
Longitudinal morpho-functional MRI for the management of incidental pulmonary nodules in patients with COPD: a nationwide multicentre trial
Lin Zhu, Shanghai / China
Author Block: L. Zhu1, L. Qian2, H-U. Kauczor2, M. O. Wielpütz2; 1Shanghai/CN, 2Heidelberg/DE
Purpose: The purpose of this study was to evaluate the capability to accurately diagnose and predict the long-term outcome of incidental pulmonary nodules in heavy smokers by MRI in multicentre trial research.
Methods or Background: Patients who participated in two rounds of same-day MRI and LDCT scans or who had histopathological proofs were included from 16 centres nationwide. The accuracy of MRI in predicting nodule growth and lung cancer was verified by LDCT and histopathological results, and the consistency of MRI and LDCT in judging the outcome of nodules was evaluated. MRI parsimonious and fuller multivariable logistic regression models were constructed.
Results or Findings: 248 patients were analysed in the present study out of 567 patients after their first round exam, with 11 patients having had histopathological proofs after the imaging examination. MRI has similar detection accuracy to LDCT for patients with malignant nodules and revealed a substantial intermethod agreement with LDCT on the long-term outcome judgment of incidental nodules based on two rounds of imaging assessment (κ=0.78-0.80). Our MRI full model showed significant improvement in the predictive accuracy of incidental nodule progression over the parsimonious model (AUC 0.91 vs 0.81, P<0.05), and shows no difference when compared to the LDCT model (P=0.45). This suggests that the MRI full model, which associated sociodemographic, clinical and characteristics based on MRI imaging, has similar potential to LDCT in diagnosing incidental pulmonary nodules as well as in progression prediction in high risk patients.
Conclusion: MRI plays a promising role in evaluating and predicting the outcome of incidental nodules in the at-risk population, which may contribute to radiation management and public health improvement.
Limitations: Most of the included incidental nodules were small and without surgery or biopsy, so LDCT served as the standard of reference for this part.
Funding for this study: This work was supported in part by grants from the German Federal Ministry of Education and Research BMBF to the German Center for Lung research (82DZL004A1, 82DZL009B1).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This research was approved by the ethics committee of the university of Heidelberg.

This session will not be streamed, nor will it be available on-demand!