Steady-state Free Procession Research Articles

Association Between Myocardial Oxygenation and Fibrosis in Duchenne Muscular Dystrophy: Analysis by Rest Oxygenation-Sensitive Magnetic Resonance Imaging.

Myocardial hypoxia has been demonstrated in many cardiomyopathies and is related to development of myocardial fibrosis. However, myocardial hypoxia and its association with myocardial fibrosis are understudied in Duchenne muscular dystrophy (DMD)-associated cardiomyopathy. To evaluate myocardial hypoxia by oxygenation-sensitive (OS) cardiac magnetic resonance imaging, and further explore its association with fibrosis. Prospective. Ninety-one DMD boys (8.78 ± 2.32) and 30 healthy boys (9.07 ± 2.30). 3 T, Balanced steady-state free procession, Modified Look-Locker inversion recovery sequence and Single-shot phase-sensitive inversion recovery sequence. Cardiac MRI data, including left ventricular functional, segmental native T1, and oxygenation signal-intensity (SI) according to AHA 17-segment model, were acquired. Patients were divided into LGE+ and LGE- groups. In patients with LGE, all segments were further classified as positive or negative segments by segmentally presence/absence of LGE. Variables were compared using Student's t, Wilcoxon, Kruskal-Wallis test and one-way analysis of variance. Bivariate Pearson or Spearman correlation were calculated to determine association between oxygenation SI and native T1. Variables with P < 0.10 in the univariable analysis were included in multivariable model. Receiver operating characteristic analysis was used to assess the performance of OS in diagnosing myocardial hypoxia. The myocardial oxygenation SI of DMD was significantly decreased in all segments compared with normal controls, and more obvious in the LGE+ segments (0.46 ± 0.03 vs. 0.52 ± 0.03). For patients with and without LGE, myocardial oxygenation SI were significantly negatively correlated with native T1 in all segments (r = -0.23 to -0.42). The inferolateral oxygenation SI was a significant independent associator of LGE presence (adjusted OR = 0.900). Myocardial hypoxia evaluated by the OS-Cardiac-MRI indeed occurs in DMD and associate with myocardial fibrosis, which might be used as a biomarker in assessing myocardial damage in DMD. 1 TECHNICAL EFFICACY: Stage 1.

Ferumoxytol-enhanced magnetic resonance imaging with volume rendering: A new approach for the depiction of internal placental structure in vivo

IntroductionPlacental function is vitally important, but placental assessment is limited by current imaging methods in vivo. The goal of this study is to determine if ferumoxytol-enhanced MR studies might be used to depict placental structure during pregnancy. MethodsTen pregnant women were referred for MRI evaluation of abnormal placentation. The study group was composed five of these patients whose placentas were normal at pathology. MR studies consisted of pre-contrast SSFSE (single-shot fast spin-echo), SSFP (steady-state free procession), diffusion, and ferumoxytol-enhanced acquisitions. The post-contrast sequences were compared to pre-contrast SSFSE, SSFP, and diffusion acquisitions for features of correspondence. MR images were also compared to histopathology for anatomic landmarks including the three-ring pattern of the functional vascular exchange unit (the placentone) created by this central cavity surrounded by a ring of clustered villi, and an outer ring of dispersed villi corresponding to the maternal venous outflow channel. The measured sizes of these features on MR were compared to reported sizes. ResultsPost-ferumoxytol images showed enhancement of the maternal blood within the placenta, notably the intervillous space and the myometrial vessels. The unenhanced fetal vessels were most visible on the MinIP (minimum intensity projection) images; the enhanced maternal vessels were most visible on the MIP (maximum intensity projection) images. Composite MIP/MinIP images show the relation of maternal and fetal circulations. The signal intensities replicate the relative contributions from enhanced maternal blood and unenhanced chorionic villi. DiscussionFerumoxytol-enhanced MR imaging can depict the internal anatomy of the placenta in vivo of clarity and detail. This could represent a new diagnostic approach to placental disorders.

Right Ventricular Remodeling Assessed by MRI in Duchenne Muscular Dystrophy.

In Duchenne muscular dystrophy (DMD), the right ventricle (RV) tends to be relatively well preserved, but characterization remains difficult due to its complex architecture. Tissue phase mapping (TPM) is a phase contrast cine MRI technique that allows for multidirectional assessment of myocardial velocities. To use TPM to elucidate relationships between myocardial structure, function, and clinical variables in DMD. Retrospective. A total of 20 patients with muscular dystrophy (median age: 16 years); 18 age-matched normal controls (median age: 15 years). Three-directional velocity encoded cine gradient echo sequence (TPM) at 1.5T, balanced steady-state free procession (bSSFP), T1 mapping with extracellular volume (ECV), and late gadolinium enhancement (LGE). TPM in basal, mid, and apical short-axis planes was performed as part of a standard MRI study with collection of clinical data. Radial, circumferential, and longitudinal velocities (Vr, Vφ, and Vz, respectively) and corresponding time to peak (TTP) velocities were quantified from TPM and used to calculate RV twist as well as intraventricular and interventricular dyssynchrony. The correlations between TPM velocities, myocardial structure/function, and clinical variables were assessed. Unpaired t-test, Wilcoxon rank-sum test, Bland-Altman analyses were used for comparisons between DMD patients and controls and between DMD subgroups. Pearson's test was used for correlations (r). Significance level: P< 0.05. Compared to controls, DMD patients had preserved RV ejection fraction (RVEF 53% ± 8%) but significantly increased interventricular dyssynchrony (Vφ: 0.49 ± 0.21 vs. 0.72 ± 0.17). Within the DMD cohort, RV dyssynchrony significantly increased with lower LV ejection fraction (intraventricular Vr and Vz: r=-0.49; interventricular Vz: r=0.48). In addition, RV intraventricular dyssynchrony significantly increased with older age (Vz: r=0.67). RV remodeling in DMD occurs in the context of preserved RVEF. Within DMD, this abnormal RV deformation is associated with older age and decreased LVEF. 4. Stage 2.

Feasibility of Single-Breath-Hold Compressed Sensing Real-Time Cine Imaging for Assessment of Ventricular Function and Left Ventricular Strain in Cardiac Magnetic Resonance

To explore the feasibility of single-breath-hold compressed sensing real-time cine imaging (CS-cine) in the assessment of ventricular function and left ventricular (LV) strain. A total of 70 subjects were enrolled prospectively, and all subjects underwent cardiac magnetic resonance imaging (cardiac MRI) using both the standard steady-state free procession cine (sta-cine) acquisition and a prototype CS-cine sequence. For both CS-cine and sta-cine imaging, continuous short-axis cine images were acquired from the base to the apex to cover the entire left ventricle, and long-axis cine images including two-, three-, and four-chamber views were also acquired. The scanning range, number of slices, slice thickness and intervals were kept identical for the two cine images of the same participant. Subjective evaluation of the image quality was performed on all cine images. For both sequences, the conventional function parameters of the left and the right ventricles and LV strain values were assessed with post-processing software analysis. The cine image quality, conventional ventricular function parameters, and LV strain values were compared between the two cine groups and the differences were examined. Inter- and intraobserver agreements for CS-cine images were measured using intraclass correlation coefficient ( ICC). Bland-Altman analysis was performed to assess reproducibility between the two cine methods. The median scanning time of CS-cine was 21 s versus 272 s for sta-cine ( P<0.001). The median image quality scores of two groups were significantly different, 4 points for sta-cine and 2 points for CS-cine ( P<0.001). Bi-ventricular end-diastolic volumes (EDV), stroke volume (SV) and ejection fraction (EF) were significantly smaller in CS-cine ( P<0.001). Nevertheless, no significant differences between the two groups in bi-ventricular ESV or LV mass were observed ( P>0.05). LV strain parameters, including the peak radial strain, peak circumferential strain and peak longitudinal strain derived from LV mid-ventricular slice, were significantly different in the two sequences ( P<0.001). Moreover, CS-cine-derived functional parameters and strain measurements have a good correlation with those of sta-cine (for RV function parameters, and left ventricular PLS, PCS values, more than 95% points fell within the limits of agreement [ LoA]; meanwhile, more than 91% points fell within the LoA for other parameters) and inter- and intraobserver agreements were strong ( ICC=0.88 to 0.99) for CS-cine. CS-cine can well realize the rapid acquisition of cine images for quantitative analysis of cardiac function, and the conventional ventricular function parameters and LV globalized strain values obtained from CS-cine imaging have good reproducibility.

Clinical usefulness of labyrinthine three-dimensional fluid-attenuated inversion recovery magnetic resonance images in idiopathic sudden sensorineural hearing loss.

Literature on the use of current magnetic resonance imaging (MRI) for patients with idiopathic sudden sensorineural hearing loss (ISSNHL) is reviewed, emphasizing the role of three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) MRI. The discussion focuses on the diagnostic role of temporal bone MRI using 3D-FLAIR and the relationship between MRI findings, clinical symptoms, and hearing outcome. The currently suggested MRI protocol for SSNHL includes a 3D T2-weighted steady-state free procession sequence or its equivalent, pre and postcontrast T1-weighted, and pre and postcontrast 3D-FLAIR sequences. The 3D-FLAIR image identifies an underlying labyrinthine condition in 24-57% of patients with ISSNHL, contributing to understanding the pathophysiologic mechanisms (e.g., labyrinthitis or labyrinthine hemorrhage). Recent studies demonstrated consistent results that initial hearing loss could be related to the signal change on the 3D-FLAIR image. Various results on 3D-FLAIR image value prediction for the final hearing outcome were shown. 3D-FLAIR MRI application identifies an underlying labyrinthine condition. Abnormal MRI findings correlate with initial hearing loss and accompanying symptoms and hearing outcome. Performing temporal bone MRI with 3D-FLAIR sequence may clarify probable ISSNHL pathophysiology, improve diagnostic accuracy, provide prognostic information to physicians, and possibly guide toward a more specific treatment.

Differences in left ventricular mass and morphology and right ventricular function differentiate phenotype-negative sarcomere gene mutation carriers from healthy volunteers

Abstract Funding Acknowledgements Type of funding sources: None. Carriers of pathogenic DNA variants (G+) causing hypertrophic cardiomyopathy (HCM) can be identified by genetic testing, before manifestation of left ventricular hypertrophy (LVH). These G+/LVH- subjects are routinely monitored for phenotypic expression, which, alongside LVH, can include other HCM-related abnormalities, including crypts and myocardial fibrosis. Cardiovascular magnetic resonance (CMR) imaging has emerged as a valuable technique in diagnosing and follow-up of HCM. In this study, we identified clinical features of subclinical HCM in a G+/LVH- population compared to healthy subjects. We studied 33 G+ subjects with CMR and a maximal wall thickness (MWT) &amp;lt;13mm, and compared them to an age- and gender-matched group of 35 healthy controls (44 ± 14 vs 48 ± 10 y, p = 0.17; 11 (33%) vs 12 (34%) men, p = 0.93). The CMR imaging protocol consisted of 1) steady state free procession cine imaging, 2) 2-dimensional late gadolinium enhancement (LGE) images in the G+ patients and 3) pre-contrast T1 mapping using a modified look-locker inverse recovery sequence. We assessed CMR examinations for features of HCM. Forward logistic regression analysis was performed to determine which of the CMR characteristics were predictive of G+ status. G+ subjects had a higher MWT (10.9 ± 1.6 vs 10.2 ± 1.3 mm, p = 0.04), a similar interventricular septal wall (IVS) thickness (8.8 ± 1.6 vs 8.7 ± 1.6 mm, p = 0.85), a smaller posterior wall (PW) and a higher IVS/PW ratio (6.6 ± 1.2 vs 7.7 ± 1.3mm, p &amp;lt; 0.001; 1.4 ± 0.3 vs 1.1 ± 0.2, p = 0.001). Indexed left ventricular (LV) mass was significantly lower in the G+ group (Table). LV function was similar (63 ± 6 vs. 61 ± 5%, p = 0.12), but right ventricular (RV) function was higher in the G+ group. They often had a characteristic hook-shaped thickening of the basal anterior wall (7 (21%) vs 0, p &amp;lt; 0.004; Figure) and more frequently exhibited myocardial crypts. Midwall LGE was present in 3 (9%) G+ subjects. Native septal T1 values were elevated in G+ patients compared to controls, although mostly within the normal range (986 ± 31 vs 963 ± 28 ms, p &amp;lt; 0.01). Crypts, indexed LV mass and RV ejection fraction were significant predictors of G+ status in logistic regression analysis (Table). CMR demonstrates significant morphological differences between the G+/LVH- population and healthy controls. Further studies are needed to assess the prognostic significance of these morphological features. Predictors of genotype-positive status Variables G+ subjects (n = 33) Controls (n = 35) P value OR for G+ status P value Left ventricular mass/BSA (g/m&amp;sup2;) 45 ± 7.4 53 ± 7.9 &amp;lt;0.001 0.86 [0.78-0.95] 0.003 Right ventricular ejection fraction (%) 58 ± 6 53 ± 4 &amp;lt;0.001 1.15 [1.00-1.32] 0.047 Crypts 17 (55%) 4 (11%) &amp;lt;0.001 9.62 [1.93-48.00] 0.006 G+: genotype-positive, OR: odds ratio Abstract Figure. CMR findings

Incremental value of cardiovascular magnetic resonance imaging in family screening for hypertrophic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Genetic testing in relatives of hypertrophic cardiomyopathy (HCM) patients can lead to early identification of carriers of pathogenic DNA variants (G+), before onset of left ventricular hypertrophy (LVH). Repeated evaluation by electrocardiography (ECG) and transthoracic echocardiography (TTE) is recommended to detect HCM during follow-up. Cardiovascular magnetic resonance (CMR) imaging has become valuable in the work-up of HCM, although its role in G+ subjects has not been extensively evaluated. In this study, we investigated the value of CMR in the G+/LVH- population. We included 55 G+ subjects who underwent CMR in addition to ECG and TTE, with a maximal wall thickness (MWT) &amp;lt;15mm on TTE. The CMR imaging protocol consisted at least of steady state free procession imaging and 2-dimensional late gadolinium enhancement (LGE) images. ECGs were considered abnormal in case of pathologic Q waves, T wave inversion or signs of LVH (by voltage criteria including Sokolow-Lyon and a Romhilt-Estes score ≥4). TTEs were abnormal in case of LVH (defined as MWT≥10mm). For both modalities, the diagnosis of HCM was based on a MWT≥13mm. The yield of CMR relative to ECG/TTE was assessed by comparing the proportion of HCM diagnoses and the presence of other phenotypic features. Forward step logistic regression was used to assess whether the presence of TTE/ECG abnormalities could predict reclassifications or abnormalities (crypts and LGE) on CMR. An overview of ECG/TTE and CMR findings is shown in the Figure. Two of 16 (13%) subjects diagnosed with HCM on TTE were reclassified as having no HCM on CMR, and 8 of 39 (21%) subjects without HCM on TTE were reclassified as HCM on CMR. These 8 subjects had a mean MWT of 15.4 ± 2.6 mm on CMR and a mean MWT difference of 4.5 ± 2.9 mm (range 1.7-9.4) compared to TTE, which in 3 cases was explained by a hook-shaped thickening of the basal anterior wall in the 2 chamber view, not visible on TTE. Compared to subjects without HCM on both modalities, the reclassified group had a significantly higher QRS duration (104 ± 14 vs 93 ± 11 ms, p = 0.03) and anterior mitral valve leaflet length (30 ± 4 vs 26 ± 3 mm, p = 0.01). Of the 13 subjects with normal ECG/TTE results, none were reclassified as HCM using CMR. The proportion of additional CMR abnormalities was large in subjects with and without abnormal ECG/TTE results (57% vs 38%, p = 0.24). Subjects with poor TTE image quality were equally likely to be reclassified compared to those with sufficient image quality (10% vs 24%, p = 0.19). Logistic regression demonstrated that the presence of TTE/ECG abnormalities (odds ratio [OR] 8.7 [1.3-59.0], p = 0.03) and age (OR 1.1 [1.0-1.2], p &amp;lt; 0.01) independently predicted reclassifications or presence of abnormalities using CMR. Additional CMR imaging reclassifies 18% of subjects. Subjects with normal ECG and TTE results are not diagnosed as HCM on CMR, but the prevalence of HCM-related abnormalities on CMR was high in subjects with and without ECG/TTE abnormalities. Abstract Figure. Diagnostic approach and CMR findings

Assessing Patient-Specific Mechanical Properties of Aortic Wall and Peri-Aortic Structures From In Vivo DENSE Magnetic Resonance Imaging Using an Inverse Finite Element Method and Elastic Foundation Boundary Conditions.

The establishment of in vivo, noninvasive patient-specific, and regionally resolved techniques to quantify aortic properties is key to improving clinical risk assessment and scientific understanding of vascular growth and remodeling. A promising and novel technique to reach this goal is an inverse finite element method (FEM) approach that utilizes magnetic resonance imaging (MRI)-derived displacement fields from displacement encoding with stimulated echoes (DENSE). Previous studies using DENSE MRI suggested that the infrarenal abdominal aorta (IAA) deforms heterogeneously during the cardiac cycle. We hypothesize that this heterogeneity is driven in healthy aortas by regional adventitial tethering and interaction with perivascular tissues, which can be modeled with elastic foundation boundary conditions (EFBCs) using a collection of radially oriented springs with varying stiffness with circumferential distribution. Nine healthy IAAs were modeled using previously acquired patient-specific imaging and displacement fields from steady-state free procession (SSFP) and DENSE MRI, followed by assessment of aortic wall properties and heterogeneous EFBC parameters using inverse FEM. In contrast to traction-free boundary condition, prescription of EFBC reduced the nodal displacement error by 60% and reproduced the DENSE-derived heterogeneous strain distribution. Estimated aortic wall properties were in reasonable agreement with previously reported experimental biaxial testing data. The distribution of normalized EFBC stiffness was consistent among all patients and spatially correlated to standard peri-aortic anatomical features, suggesting that EFBC could be generalized for human adults with normal anatomy. This approach is computationally inexpensive, making it ideal for clinical research and future incorporation into cardiovascular fluid-structure analyses.

Rare Cardiac Mass Assessed by Cardiac Magnetic Resonance

Abstract A 43 year old male was referred to our center for assessment of the cardiac involvement in Erdheim-Chester disease (EHD) by cardiac magnetic resonance (CMR). The patient presented with a history of bone involvement as well as retroperitoneal mass, demonstrated to consist fibrosis as well as histiocyte infiltration. The CMR examination included cine (SSFP – steady state free procession), T1 weighted (T1w) and T2 weighted (T2w) sequences, as well as late enhancement images 10 minutes after gadolinium based contrast injection (0.2 mmol/kg). The acquired images showed normal dimensions and function for both right and left cardiac chambers. However, a cardiac mass was revealed in the free wall of the right atrium and the junction with the right ventricle, with clear borders and a diameter of 2.5 cm (Image 1). The tissue was best viewed on axial sequences and was isointense on cine, T1w and T2w images and was mildly enhanced on LGE images. Consequently, the diagnosis of cardiac involvement in EHD was confirmed. The patient was started on specific treatment for EHD and 3-year CMR follow-up showed regression of cardiac involvement. Erdheim-Chester disease is a rare disorder most frequently characterized by non-Langerhans histiocytic multifocal osteosclerotic lesions, with multisystemic granulomatosis and widespread manifestations, as well as highly variable severity(1). ECD affects the cardiovascular system in 75% of patients with infiltration of the pericardium and the right atrioventricular septum being the most common presentation. Typically the mass appears isointense on T1 and T2 weighted images and has low contrast enhancement, as was the case in our patient. In approximately 60% of cases death occurs because of cardiac complications, like pericardial tamponade, myocardial infarction, cardiomyopathy or arrhythmias(2). Patients may sometimes be successfully treated with biologic therapy, interferon alpha or radiotherapy.

Reduced regional flow in the left ventricle after anterior acute myocardial infarction: a case control study using 4D flow MRI

BackgroundAcute myocardial infarction (AMI) alters left ventricular (LV) hemodynamics, resulting in decreased global LV ejection fraction and global LV kinetic energy. We hypothesize that anterior AMI effects localized alterations in LV flow and developed a regional approach to analyze these local changes with 4D flow MRI.Methods4D flow cardiac magnetic resonance (CMR) data was compared between 12 anterior AMI patients (11 males; 66 ± 12yo; prospectively acquired in 2016–2017) and 19 healthy volunteers (10 males; 40 ± 16yo; retrospective from 2010 to 2011 study). The LV cavity was contoured on short axis cine steady-state free procession CMR and partitioned into three regions: base, mid-ventricle, and apex. 4D flow data was registered to the short axis segmentation. Peak systolic and diastolic through-plane flows were compared region-by-region between groups using linear models of flow with age, sex, and heart rate as covariates.ResultsPeak systolic flow was reduced in anterior AMI subjects compared to controls in the LV mid-ventricle (fitted reduction = 3.9 L/min; P = 0.01) and apex (fitted reduction = 1.4 L/min; P = 0.02). Peak diastolic flow was also lower in anterior AMI subjects compared to controls in the apex (fitted reduction = 2.4 L/min; P = 0.01).ConclusionsA regional method to analyze 4D LV flow data was applied in anterior AMI patients and controls. Anterior AMI patients had reduced regional flow relative to controls.

In Vivo Quantification of Regional Circumferential Green Strain in the Thoracic and Abdominal Aorta by Two-Dimensional Spiral Cine DENSE MRI

Regional tissue mechanics play a fundamental role in the patient-specific function and remodeling of the cardiovascular system. Nevertheless, regional in vivo assessments of aortic kinematics remain lacking due to the challenge of imaging the thin aortic wall. Herein, we present a novel application of displacement encoding with stimulated echoes (DENSE) magnetic resonance imaging (MRI) to quantify the regional displacement and circumferential Green strain of the thoracic and abdominal aorta. Two-dimensional (2D) spiral cine DENSE and steady-state free procession (SSFP) cine images were acquired at 3T at either the infrarenal abdominal aorta (IAA), descending thoracic aorta (DTA), or distal aortic arch (DAA) in a pilot study of six healthy volunteers (22-59 y.o., 4 females). DENSE data were processed with multiple custom noise reduction techniques including time-smoothing, displacement vector smoothing, sectorized spatial smoothing, and reference point averaging to calculate circumferential Green strain across 16 equispaced sectors around the aorta. Each volunteer was scanned twice to evaluate interstudy repeatability. Circumferential Green strain was heterogeneously distributed in all volunteers and locations. The mean spatial heterogeneity index (standard deviation of all sector values divided by the mean strain) was 0.37 in the IAA, 0.28 in the DTA, and 0.59 in the DAA. Mean (homogenized) peak strain by DENSE for each cross section was consistent with the homogenized linearized strain estimated from SSFP cine. The mean difference in peak strain across all sectors following repeat imaging was -0.1±2.3%, with a mean absolute difference of 1.7%. Aortic cine DENSE MRI is a viable noninvasive technique for quantifying heterogeneous regional aortic wall strain and has significant potential to improve patient-specific clinical assessments of numerous aortopathies, as well as to provide the lacking spatiotemporal data required to refine patient-specific computational models of aortic growth and remodeling.

T2-weighted balanced steady-state free procession MRI evaluated for diagnosing placental adhesion disorder in late pregnancy.

This study evaluated the imaging characteristics and accuracy of T2-weighted (T2W) balanced steady-state free procession (b-SSFP) magnetic resonance imaging, relative to b-SSFP or single-shot fast spin echo (SSFSE), for the diagnosis of placental adhesion disorder (PAD). Fifty-one pregnant patients suspected of PAD were examined with T2W b-SSFP, b-SSFP and SSFSE. The image types were independently analysed for signs of PAD: abnormal placental bulge (APB), dark intraplacental bands (DIB), placental heterogeneity (PH) and placental protrusion into adjacent structures (PPAS). The sequences were compared for muscle-to-placenta signal ratio, signs of PAD and area under the receiver operating characteristic curve (AUC) for diagnostic accuracy of PAD. PAD was confirmed in 34 women. The muscle-to-placenta signal ratio was highest in the T2W b-SSFP. The diagnostic rates of APB in T2W b-SSFP were comparable to that of b-SSFP, but were significantly higher than that of SSFSE. The rates of PH in SSFE were comparable to that of b-SSFP, but both were significantly lower than that of T2W b-SSFP. The rates of DIB were significantly higher in T2W b-SSFP images compared with SSFSE. Rates of PPAS were comparable among three sequences. The AUCs of the T2W b-SSFP, b-SSFP and SSFSE were 0.966, 0.890 and 0.823, respectively. T2W b-SSFP has high diagnostic accuracy for PAD relative to SSFSE or b-SSFP, which may be due to its high SNR, T2-weighting and lack of blur. • Signal myometrium-to-placenta ratio was highest in the T2W b-SSFP images. • Diagnostic rate of APB in T2W b-SSFP was highest. • Diagnostic rate of DIB was higher in T2W b-SSFP than in SSFSE. • Diagnostic rate of PH in T2W b-SSFP was highest. • Maximum AUC for diagnostic accuracy of PAD was in T2W b-SSFP.

Detection of endolymphatic hydrops using traditional MR imaging sequences

PurposeThe purpose of this study was to determine whether Meniere's disease (MD) produces endolymphatic cavity size changes that are detectable using unenhanced high-resolution T2-weighted MRI. Materials & methodsThis retrospective case-control study included patients with documented MD who had a high-resolution T2-weighted or steady-state free procession MRI of the temporal bones within one month of diagnosis, between 2002 and 2015. Patients were compared to age- and sex- matched controls. Cross sectional area, length, and width of the vestibule and utricle were measured in both ears along with the width of the basal turn of the cochlea and its endolymphatic space. Absolute measurements and ratios of endolymph to perilymph were compared between affected, contralateral, and control ears using analysis of variance and post-hoc pairwise comparisons. ResultsEighty-five case-control pairs were enrolled. Mean utricle areas for affected, contralateral, and control ears were 0.038cm2, 0.037cm2, and 0.033cm2. Mean area ratios for affected, contralateral, and control ears were 0.32, 0.32, and 0.29. There was a statistically significant difference between groups for these two variables; post-hoc comparisons revealed no difference between affected and contralateral ears in Meniere's patients, while ears in control patients were different from the ears of patients with MD. All other measurements failed to show significant differences. ConclusionsEnlargement of the endolymphatic cavity can be detected using non-contrast T2-weighted MRI. MRI, using existing protocols, can be a useful diagnostic tool for the evaluation of MD, and intratympanic or delayed intravenous contrast may be unnecessary for this diagnosis.

Reference values of cardiac ventricular structure and function by steady-state free-procession MRI at 3.0T in healthy adult chinese volunteers.

To establish normal reference values of left ventricular (LV) and right ventricular (RV) dimension, volume, mass, and ejection fraction in a Chinese population using cardiac magnetic resonance imaging (MRI). A total of 120 (60 males; 60 females; 23-83 years) healthy Han Chinese subjects without cardiovascular disease or risk factors were recruited. They underwent comprehensive MRI examination at 3.0T. LV/RV morphology and function were evaluated by steady-state free-procession (SSFP) sequence. Parameters were analyzed according to a standard postprocessing protocol. Significant differences in LV size, mass, volume, and ejection fraction (EF) between sexes were noted (all P < 0.05). After indexing using body surface area (BSA), LV end-diastolic volume (EDV), and LV mass index were greater in males than in females (76.5 vs. 68.7 mL/m, P < 0.001; 52.9 vs. 45.1 g/m, P < 0.001; respectively). LVEF was lower in males than in females (64.6% vs. 67.1%, P = 0.007, respectively). RV volume was higher and RVEF lower in males compared with females (75.3 vs. 62.7 mL/m, P < 0.001; 59.9% vs. 62.6%, P = 0.001, respectively). Age was associated significantly with indices of LV and RV volume in females (left ventricular end-diastolic volume index: r = -0.41 P = 0.001; left ventricular end-systolic volume index: r = -0.37 P = 0.004; left ventricular end-diastolic volume index: r = -0.53 P < 0.001; right ventricular end-systolic volume index: r = -0.43 P < 0.001), but not in males (all P > 0.05). These data suggest that sex and age affect ventricular parameters in healthy Han Chinese subjects without cardiovascular disease or risk factors. 2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1684-1692.

Cerebral oxygen delivery is reduced in newborns with congenital heart disease

ObjectiveTo investigate preoperative cerebral hemodynamics in newborns with congenital heart disease. We hypothesized that cerebral blood flow and oxygen delivery would be decreased in newborns with congenital heart disease compared with controls. MethodsUsing a “feed-and-sleep” approach to performing neonatal magnetic resonance imaging, we measured cerebral blood flow by using a slice prescription perpendicular to the right and left internal carotid arteries and basilar artery at the level of the clivus. We calculated brain volume by segmenting a 3-dimensional steady-state free procession acquisition of the whole brain, allowing quantification of cerebral blood flow indexed to brain volume. Cerebral oxygen delivery was calculated as the product of cerebral blood flow and preductal systemic arterial oxygen content obtained via a combination of conventional pulse oximetry and laboratory analysis of venous blood samples for hemoglobin concentration. ResultsA complete set of measurements were obtained in 32 newborns with heart disease and 31 controls. There was no difference in gestational age between the heart disease and control groups. There was no difference in cerebral blood flow compared with controls (103.5 ± 34.0 vs 119.7 ± 40.4 mL/min), whereas cerebral oxygen delivery was significantly lower in the congenital heart disease subjects (1881 ± 625.7 vs 2712 ± 915.7 mLO2/min). Ten newborns with congenital heart disease had diffuse excessive high signal intensity in their white matter and 2 had white matter injury whereas another 5 had both. ConclusionsNewborns with unrepaired cyanotic congenital heart disease have decreased cerebral oxygen delivery due to arterial desaturation. If brain growth and development are adversely affected through oxygen conformance, our findings could have clinical implications in terms of timing of surgical repair.

11 Left ventricular end diastolic filling pressure predicted by left atrial strain measured by feature tracking

Introduction Left ventricular end-diastolic filling pressure (LVEDP) is an invasive measure of LV function obtained at cardiac catheterisation (CC) that predicts prognosis and guides therapeutic strategy. Echocardiographic E/E’ ratio has been shown to be inaccurate for estimation of LVEDP. Feature-tracking cardiovascular magnetic resonance (FT-CMR) is a novel method for quantification of myocardial deformation and can be used to quantitatively assess left atrial (LA) function. Currently there is no validated MRI parameter that estimates LVEDP. We hypothesised that LA strain correlates to LVEDP. Methods 14 patients in sinus rhythm, with severe AS underwent a 1.5T CMR protocol (Ingenia, Phillips Healthcare, Best, The Netherlands). LVEDP was recorded at the time of CC by standard techniques. 4 chamber and mid ventricular short axis steady state free procession cine images were obtained: LA endocardial and epicardial borders were traced manually on the end-diastolic slice and strain measurements were calculated using commercially available post-processing software (CVI42, Circle Cardiovascular Imaging, Calgary, Alberta, Canada). Results Patients were divided into 2 groups: low EDP (13 ± 2.4mmHg) and high EDP (36.1 ± 3.4mmHg) (p Conclusion LA function (PALS) as measured by FT-CMR is independently associated with LVEDP and may have a role in predicting LV filling pressures via a routine CMR protocol.

The accuracy and effectiveness of self-gating signals in free-breathing 3D cardiac cine MRI

Background Conventional cardiac cine magnetic resonance imaging (MRI) is typically based on the segmented data acquired by breath-hold 2D balanced steady-state free procession (SSFP) pulse sequence [1]. However, the slice misregistration caused by the variation of breath holding positions could compromise the effectiveness of 2D SSFP, and breath-hold makes it difficult for pediatric patients or patients who suffer from congestive heart failure to cooperate [2]. Recently, respiratory and cardiac selfgated free-breathing (FB) cardiac cine MRI have been proposed for overcoming these barriers [3]. This approach could provide similar image quality and functional measurements without using electrocardiographic (ECG) or any peripheral equipment compared with 2D SSFP. However, the precision comparison between the self-gating signals and the external signals needs to be studied systematically.

Cardiac MRI right ventricle / left ventricle (RV/LV) volume ratio improves detection of RV enlargement.

To determine the normal range of the ratio of right ventricular (RV) end-diastolic volume to left ventricular (LV) end-diastolic volume by magnetic resonance imaging (MRI) and examine whether combining this volume ratio with RVEDV indexed to body surface area (RVEDVi) increased the detection of RV dilation in patients with pulmonary arterial hypertension (PAH). MRI-derived ventricular function and volumes were measured in a control group (n = 152) and in patients with PAH (n = 46). Images were acquired with a 1.5T Siemens or a 1.5T Philips scanner using a steady-state free procession sequence. Proposed criteria for the detection of RV enlargement, including RVEDVi alone, RV/LV volume ratio alone, and combining both criteria, were evaluated in both groups. The range (mean ± 2 standard deviations) for the volume ratio in the normal population was found to be 0.906-1.266; there was no difference between genders (P = 0.70). Combining this ratio with RVEDVi detected RV enlargement in 21.7% (P < 0.001) PAH patients (volume ratio ≥1.27) who were not identified by the RVEDVi alone (>104 mL/m(2) for females and >113 mL/m(2) for males). Combining RV/LV volume ratio with indexed RVEDV increased detection of RV enlargement in a PAH population. This result may have potential impact in RV size assessment. J. Magn. Reson. Imaging 2016;43:1379-1385.

97 Men and Women differ in their Adaptation to Aortic Stenosis and in Reverse Remodelling following Aortic Valve Intervention

<h3>Background</h3> Outcomes following aortic valve intervention may differ according to gender. It has been suggested that men and women adapt differently to aortic stenosis (AS) but the effect of gender on left ventricular (LV) remodelling following valve intervention is not well described. We sought to establish using cardiac magnetic resonance (CMR) imaging, the reference standard non-invasive technique for the assessment of LV mass (LVM) and function, whether there was any difference between genders in LV remodelling in severe AS at baseline and reverse remodelling six months following aortic valve intervention. <h3>Methods</h3> 100 patients (60 men) with symptomatic severe AS undergoing surgical or percutaneous aortic valve intervention were prospectively recruited between April 2009 and March 2014. Patients with contraindications to CMR were excluded and all patients provided informed written consent. All patients underwent an identical 1.5T CMR protocol (Intera, Philips) prior to and at a median of 6 months following aortic valve intervention (IQR 5–6 months). Multi slice, multiphase imaging was carried out using a standard steady-state free procession pulse sequence in axial and short axis to cover the entire left heart. Quantitative analysis was performed using dedicated computer software (CVI42, Circle Cardiovascular Imaging, Alberta, Canada). <h3>Results</h3> Basic demographic, clinical and echocardiographic data can be seen in Table 1. Women were older than men but were similar in terms of co-morbidity, surgical risk and valvular haemodynamics. At baseline, women had lower indexed LVM (LVMi) than men and a smaller indexed LV end diastolic volume (LVEDVi). Baseline LV ejection fraction (LVEF) and indexed left atrial volume (LAVi) were similar between sexes. Following valvular intervention, LVMi was significantly reduced in both sexes, however, this was more marked in men (18.28 ± 10.63 vs 12.69 ± 8.84, p = 0.007). There was an improvement in LV longitudinal function and a decrease in LAVi in men but not in women. Neither group experienced a significant change in LVEF following intervention (men 54.84 ± 12.94% to 56.52 ± 10.50%, p = 0.093; women 58.61 ± 10.57 to 60.20 ± 11.00, p = 0.129). Both groups also experienced a significant reduction in LVEDVi following valve intervention, with a trend towards a more pronounced reduction in men (men 11.55 ± 20.31 ml/m² vs women 5.39 ± 14.10 ml/m², p = 0.141). <h3>Conclusion</h3> Men and women with AS remodel differently with more hypertrophy and larger LV cavity size in men. Six months following valvular intervention, men but not women experience an improvement in LV longitudinal function and a decrease in left atrial size. These surrogate markers of a reduced left atrial pressure may be accounted for by the greater magnitude of LVM regression seen in men.

95 Left Ventricular Mass Regression Occurs very early following Transcatheter Aortic Valve Implantation for Severe Aortic Stenosis

<h3>Background</h3> The effect of transcatheter aortic valve replacement (TAVR) on very early left ventricular remodelling has not previously been evaluated. Left ventricular mass (LVM) regression at 30 days (assessed using echocardiography) has been linked to a 50% reduction in re-hospitalisation in the first year following TAVR. We sought to establish using cardiac magnetic resonance (CMR) imaging, the reference standard imaging technique for LVM quantification, whether LVM regression occurs very early following-TAVR. <h3>Methods</h3> 27 patients with symptomatic severe aortic stenosis undergoing TAVR were prospectively enrolled between June 2013 and April 2014. Patients with contraindications to CMR were excluded and all patients provided informed written consent. All patients underwent an identical 1.5T CMR protocol (Intera, Philips) prior to and at a median of 5 days following TAVR (IQR 2 days). Multislice, multi-phase cine imaging was carried out using a standard steady-state free procession pulse sequence in the short axis to cover the entire left ventricle. Quantitative analysis was performed using dedicated computer software (CVI⁴², Circle Cardiovascular Imaging, Alberta, Canada). LVM was calculated by the formula (epicardial volume – endocardial volume) x myocardial density (1.05 g/cm³). <h3>Results</h3> Basic patient, echocardiographic and procedural characteristics can be seen in Table 1. At a median of 5 days following TAVR, mean LVM regressed by 12% from 129.5 +/- 32.5 g to 114.2+/-31 g and indexed LVM (LVMi) reduced from 69.4 ± 15.2 g/m² to 61.3 ± 15.1 g/m²(Figure 1). There was no significant change in indexed left ventricular diastolic volume (96.9 ± 24.5 to 96.8 ± 19.3 ml/m², p = 0.79), LV ejection fraction (54.0 ± 14.6 to 58.4 ± 27.4%, p = 0.49) or indexed left atrial volume (71.5 ± 22.6 to 67.7 ± 22.1 ml/m², p = 0.43). Mean LVM regression was similar between the Medtronic and Boston valve types (14.3 ± 10.4 gVs 16.5 ± 9.9 g, p = 0.58). There was no correlation between Valvulo-arterial impedance (ZVA) and LVM regression (r = 0.02, p = 0.93). There was no difference in mean LVMi regression according to gender (women 8.3 ± 2.8 g/m² Vs men 8.0 ± 5.7 g/m², p = 0.83). TAVR valve size did not appear to impact on early LVM regression. LVMi regression was similar between those with a normal baseline LVM and those with an elevated baseline LVM (defined as 83 g/m² in men and 67 g/m²) in women (7.8 ± 4.8 g Vs 9.0 ± 5.7 g, p = 0.60). 16 patients had evidence of late gadolinium enhancement (LGE) at baseline. There was a trend towards increased LVMi regression in those without LGE at baseline compared with those with LGE (10.1 ± 4.7 g/m²Vs 6.4 ± 4.7 g/m², p = 0.07). <h3>Conclusions</h3> LVM regression begins very early following TAVR and occurs before changes in cavity size or ejection fraction which is likely to be a result of an immediate reduction in wall stress. The type of valve implanted does not appear to influence early LVM regression. <h3>Funding</h3> This study was part funded by the BHF (PG/11/126/29321).