Research Presentation Session
06:10L. Pennig, Cologne / DE
Purpose:
To compare a novel compressed SENSE accelerated (factor 9) ECG- and respiratory-triggered 3D relaxation-enhanced angiography without contrast and triggering (REACT-non-CE-MRA) with standard non-ECG-triggered time-resolved 4D contrast-enhanced MRA (4D CE-MRA) for imaging of the pulmonary vasculature in patients with congenital heart disease (CHD) at 1.5T.
Methods and materials:This retrospective analysis of 25 patients (06/2018-04/2019) with known or suspected CHD was independently conducted by two radiologists executing measurements on REACT-non-CE-MRA and 4D CE-MRA on 7 dedicated points (inner-edge): main pulmonary artery (MPA), right and left pulmonary artery, right superior and inferior pulmonary vein, left superior (LSPV), and inferior pulmonary vein. The image quality for arteries and veins was evaluated on a four-point scale in consensus.
Results:23 of 25 patients presented with CHD. There was a high interobserver agreement for both methods of imaging at the pulmonary arteries (ICC ≥ 0.96); at pulmonary veins, REACT-non-CE-MRA showed a slightly higher agreement, pronounced at LSPV (ICC 0.946 vs 0.895). Measurements in 4D CE-MRA reached higher diameter values compared to REACT-non-CE-MRA at the pulmonary arteries with significant difference (e. g. MPA: mean 0.408 cm, p=0.002). REACT-non-CE-MRA (average acquisition time 07:01 ± 02:44 min) showed significantly better image quality than 4D CE-MRA at the pulmonary arteries (3.84 vs 3.32, p=0.0002) and veins (3.32 vs 2.72, p=0.0152).
Conclusion:Compressed SENSE accelerated 3D REACT-non-CE-MRA allows for reliable and fast imaging of the pulmonary vasculature with higher image quality and slightly higher interobserver agreement than 4D CE-MRA without contrast agent and associated disadvantages. Therefore, it represents a clinically suitable technique for patients requiring repetitive imaging of the pulmonary vessels, e.g. patients with CHD.
Limitations:A retrospective study. No comparison to DSA.
Ethics committee approvalEthics committee approval was given and consent was waived.
Funding:No funding was received for this work.
05:18M. Sorkun, İstanbul / TR
Purpose:
Although congestive hepatopathy is well explained in Fontan circulation and intravoxel incoherent motion (IVIM) was performed for liver injury, no reports have been published about liver injury in post-repair TOF patients by IVIM parameters. We aimed to research in post-repair TOF patients whether cardiac MRI (CMR) and laboratory findings correlate with liver injury by IVIM parameters.
Methods and materials:30 patients with post-repair TOF (15.46±7.64 years old, F/M: 15/15) and 25 healthy controls (18.53±5.73 years old, F/M: 15/10) were included. IVIM sequences were revealed after CMR examination by a 1.5T scanner and 32-channel phased-array surface coil.
IVIM values (D, D*, and perfusion fraction) were measured by locating ROI in 8 segments of the liver. Pulmonary artery regurgitation fraction (RF), right and left end-diastolic volume index (LVEDVI, RVEDVI), and ejection fraction (LV-EF, RV-EF) were correlated with IVIM parameters in post-repair TOF patients.
Results:Mean LVEDVI, LV-EF, RVEDVI, RV-EF, and pulmonary artery RF were 92.3±21.43ml/m2, 48.63±5.96%, 172.57±41.32ml/m2, 39.53±6.37%, and 46.03±10.83, respectively. There was a significant difference between DWI, DTrue, and perfusion fraction of post-repair TOF (DWI: 177.50±126.78 mm2/second versus 205.70±82.15 mm2/second (p = 0.00318), DTrue 0.00165±0.0005 mm2/second versus 0.00144±0.0008 mm2/second, D* 0.068±0.075 versus 0.079±0.074 mm2/second (p = 0.12602), perfusion fraction 34.68±16.95% versus 29.57±12.56% (p =0.00001), and D*fraction 0.365±0.089 % versus 0.380±0.077%, respectively). There was no statistically significant correlation between IVIM parameters and CMRI measurements.
Conclusion:Liver injury can be seen independently from cardiac parameters. Evaluation of the liver should be added to annual cardiac check-ups. DWI, DTrue, and perfusion fraction parameters can be used for evaluating liver injury in post-repair TOF patients and assessing capillary perfusion and connective tissue/cell density by IVIM sequences.
Limitations:A relatively small sample size. A lack of histopathologic correlation with imaging.
Ethics committee approvalInstitutional Review Board approval. Written informed consent was obtained.
Funding:No funding was received for this work.
03:57V. Bordonaro, Rome / IT
Purpose:
To evaluate the diagnostic role of native T1, ECV, and T2 values of paediatric cardiac tumours.
Methods and materials:We retrospectively included 8 paediatric patients (mean age 8.25 ± 3.62 years, range 2-16; 6 femmine) with suspected cardiac masses (2 fibromas, 2 angiomas, 1 rhabdomyoma, 1 teratoma, 1 myxoma, and 1 lipoma) who underwent cardiac MRI on a 1.5T scanner using T2 and pre- and post-contrast T1 mapping sequences. Native T1, ECV, and T2 values were obtained as an average among 3 non-overlapping ROIs placed into the lesion and an additional ROI covering the whole mass. The analysis was performed by two experienced readers, blinded to the suspected diagnosis.
Results:The 2 fibromas showed native T1 values of 972 ± 96 ms, ECV values of 100% ± 2, and T2 of 47 ± 2 ms. The 2 angiomas had native T1 of 1,310 ± 48 ms and ECV of 57% ± 5 and T2 of 78 ± 2 ms. The rhabdomyoma had native T1 of 1,420 ms, ECV of 29%, and T2 of 73 ms. The teratoma showed native T1 values of 1,378 ms, ECV of 29%, and T2 of 58 ms. The myxoma had native T1 values of 1,644 ms, ECV of 74%, and T2 of 126 ms. The lipoma showed native T1 values of 215 ms, undetectable ECV, and T2 of 89 ms.
Conclusion:Preliminary data obtained from this small series of paediatric tumours suggests that ECV values trend towards a higher reproducibility and better correlates with the suspected diagnosis derived from a conventional MRI approach compared to native T1 and T2 values (e.g. ECV=100% in fibromas, normal ECV in rhabdomyoma, and ECV equal to plasmatic component in angiomas).
Limitations:n/a
Ethics committee approvaln/a
Funding:No funding was received for this work.
06:00T. Tazhigaliyeva, Nur-Sultan / KZ
Purpose:
To explore the possibilities of CT-angiocardiography in the single ventricle of the heart (SVH) diagnostics.
Methods and materials:Studies were conducted in the radiology department of JSC “National Research Cardiac Surgery Center” from October 2011 to December 2018, inclusive. 1,844 patients with suspected CHD were examined, 125 (6,8%) of whom had a SVH: females - 59 (47,2%), males - 66 (52,8%).
Results:The studies results of 125 SVH patients were analysed; 70 (56%) via right ventricular hypoplasia (type A), 32 (25.6%) via left ventricular hypoplasia (type B), and 23 (18.4%) via a single ventricle (type C).
A single ventricle was diagnosed at the age of 1 up to 6 months in 74 (59.2%) patients, from 6 months to 1 year in 14 (11.2%) patients, from 1 to 5 years in 18 (14.4%) patient, from 5 to 10 years in 4 (3.2%) patients, and over 10 years in 15 (12%) patients.
SVH with other CHDs combination: atrial septal defect in 86 (68.8%) patients, patent ductus arteriosus in 70 (56%) patients, transposition of the great arteries in 51 (40.8%) patients, ventricular septal defect in 57 (45.6%) patients, pulmonary atresia in 28 (22.4%) patients, anomalous pulmonary veins drainage in 26 (20.8%) patients, patent foramen ovale in 19 (15.2%) patients, double superior vena cava in 15 (12%) patients, and coarctation of the aorta in 9 (7.2%) patients.
89 (71.2%) patients were operated on and 36 (28.8%) were not operated on, of which 56 had positive outcomes (62.9%) and 34 resulted in death (38.2%).
Conclusion:CT-angiocardiography is a highly informative and minimally invasive method for SVH diagnostics, replacing invasive methods such as cardiac catheterisation and angiocardiography. Sensitivity was 96.7%, specificity was 97.4%, and accuracy was 96.7%.
Limitations:n/a
Ethics committee approvaln/a
Funding:No funding was received for this work.
04:24A. Meloni, Pisa / IT
Purpose:
We evaluated if changes in myocardial iron overload (MIO) were related to baseline hepatic iron or changes in hepatic iron overload in children with thalassemia major (TM).
Methods and materials:We considered 68 TM patients enrolled in the MIOT project with <18 years at the first MRI and who performed a follow-up study at 18±3 months.
Myocardial and hepatic iron burdens were quantified by the T2* technique. Liver T2* values were converted into liver iron concentration (LIC) values.
Results:Baseline global heart T2* values were 29.72±11.21 ms and 16 patients showed baseline MIO (T2*<20 ms).
Mean percentage changes in global heart T2* values per month were 0.66±1.70 and they were significantly higher in patients with baseline MIO (1.99±2.53% vs 0.25±1.09% ms; P=0.002).
Percentage changes in global heart T2* values/month were not associated to initial MRI LIC values (R=0.048; P=0.695) or to final MRI LIC values (R=-0.134; P=0.277).
No correlation was detected between % changes in heart T2* and MRI LIC values (R=-0.244; P=0.067).
Conclusion:In paediatric TM patients, changes in MIO are not correlated to baseline MRI LIC values and changes in hepatic iron. Our data seems to not support the hypothesis that it is necessary to clean the liver before removing MIO.
Limitations:The limited sample size, however, TM is a rare disease.
Ethics committee approvalThe study complied with the Declaration of Helsinki. The institutional review board approved this study. For all patients, parents gave their informed consent to the protocol.
Funding:The MIOT project receives “no-profit support” from industrial sponsorships (Chiesi Farmaceutici S.p.A. and ApoPharma Inc.).
08:56T. Emrich, Mainz / DE
Purpose:
Left-to-right shunts (L-R-Shunt) lead to volume overload of the right ventricular system, pulmonary hypertension, and alterations of the RV myocardium, resulting in adverse cardiac events. CMR is able to detect L-R-Shunts by comparison of phase-contrast measurements of pulmonary and aortic flow (Qp/Qs-ratio), which is not routinely done in clinical CMR. T2-mapping is generally used for the analysation of myocardial oedema. Additionally, it is sensitive to the oxygenation of blood. This work evaluates an easy screening tool for the evaluation of L-R-Shunts using T2-mapping.
Methods and materials:We retrospectively analysed the ratio of T2-relaxation times of the LV/RV blood pool and Qp/Qs-ratio by phase-contrast-imaging from 5 patients with established relevant L-R-shunts. 7 healthy volunteers were used as a control group. Qp/Qs-ratio was calculated by dedicated measurements of pulmonary and aortic flow. In routinely acquired T2-maps of the mid-ventricular slice, the ratio between left and right ventricular blood pool T2-relaxation time was calculated.
Results:Compared to the control group, the L-R-Shunt-group showed relevant elevation of Qp/Qs and RV volume overload. T2 RV/LV-Ratio was significantly raised in patients with L-R-Shunts (0.93vs0.70, p=0.005). A ratio of >0.82 showed a 100% sensitivity and 85.7% specificity for detection of L-R-Shunts, resulting in a positive and negative predictive value of 83.3%, resp 100%. Alterations could also be depicted easily by visual assessment.
Conclusion:RV-LV blood pool T2-relaxation time ratio seems to be an easy and reliable method for the screening of L-R-Shunts. Elevated ratios of >0.82 should lead to a dedicated evaluation of Qp/Qs-ratio to determine the relevance of an L-R-Shunt. Despite its promising application, our preliminary results need to be validated in a larger study cohort.
Limitations:A single-centre study.
Ethics committee approvalThe study was approved by the local ethics committee (2018-13520/837.196.13/837.477.14).
Funding:No funding was received for this work.