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Background Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of pulmonary embolism potentially curable by surgery. Perfusion scintigraphy is currently advocated as the imaging modality of choice to exclude CTEPH due to its high sensitivity. We have evaluated the diagnostic utility of lung perfusion MRI. Methods Consecutive patients attending a pulmonary hypertension referral centre undergoing lung perfusion MRI, perfusion scintigraphy, CT pulmonary angiography (CTPA) and right heart catheterisation within 14 days were identified. Results Of 132 patients, 78 were diagnosed as having CTEPH. Lung perfusion MRI correctly identified 76 patients as having CTEPH with an overall sensitivity of 97%, specificity 92%, positive predictive value 95% and negative predictive value 96% compared with perfusion scintigraphy (sensitivity 96%, specificity 90%) and CTPA (sensitivity 94%, specificity 98%). No cases of surgically accessible CTEPH were missed with either modality. Conclusions Lung perfusion MRI has high sensitivity equivalent to perfusion scintigraphy in diagnosing CTEPH but does not require ionising radiation, making it an attractive initial imaging modality to assess patients with suspected CTEPH.

Background Native T1 may be a sensitive, contrast-free, non-invasive cardiovascular magnetic resonance (CMR) marker of myocardial tissue changes in patients with pulmonary artery hypertension. However, the diagnostic and prognostic value of native T1 mapping in this patient group has not been fully explored. The aim of this work was to determine whether elevation of native T1 in myocardial tissue in pulmonary hypertension: (a) varies according to pulmonary hypertension subtype; (b) has prognostic value and (c) is associated with ventricular function and interaction. Methods Data were retrospectively collected from a total of 490 consecutive patients during their clinical 1.5 T CMR assessment at a pulmonary hypertension referral centre in 2015. Three hundred sixty-nine patients had pulmonary hypertension [58 ± 15 years; 66% female], an additional 39 had pulmonary hypertension due to left heart disease [68 ± 13 years; 60% female], 82 patients did not have pulmonary hypertension [55 ± 18; 68% female]. Twenty five healthy subjects were also recruited [58 ±4 years); 51% female]. T1 mapping was performed with a MOdified Look-Locker Inversion Recovery (MOLLI) sequence. T1 prognostic value in patients with pulmonary arterial hypertension was assessed using multivariate Cox proportional hazards regression analysis. Results Patients with pulmonary artery hypertension had elevated T1 in the right ventricular (RV) insertion point (pulmonary hypertension patients: T1 = 1060 ± 90 ms; No pulmonary hypertension patients: T1 = 1020 ± 80 ms p  < 0.001; healthy subjects T1 = 940 ± 50 ms p  < 0.001) with no significant difference between the major pulmonary hypertension subtypes. The RV insertion point was the most successful T1 region for discriminating patients with pulmonary hypertension from healthy subjects (area under the curve = 0.863) however it could not accurately discriminate between patients with and without pulmonary hypertension (area under the curve = 0.654). T1 metrics did not contribute to prediction of overall mortality (septal: p  = 0.552; RV insertion point: p  = 0.688; left ventricular free wall: p  = 0.258). Systolic interventricular septal angle was a significant predictor of T1 in patients with pulmonary hypertension ( p  < 0.001). Conclusions Elevated myocardial native T1 was found to a similar extent in pulmonary hypertension patient subgroups and is independently associated with increased interventricular septal angle. Native T1 mapping may not be of additive value in the diagnostic or prognostic evaluation of patients with pulmonary artery hypertension.

Assessment of lung function in PCD may have a significant clinical overlap with cystic fibrosis (CF) (3), the aim being to identify small but clinically significant airways obstruction within the lung. Hyperpolarized gas ventilation magnetic resonance imaging (MRI) has been proven to be highly sensitive to early lung disease (7, 8), response to treatment (9), and the deterioration of lung function (10) in CF, and is well tolerated by children as young as 5 years of age (11). From these images two indices were calculated: 1) ventilation defect percentage (VDP), which quantifies the percentage of the lung volume that is not ventilated; and 2) the mean coefficient of variance of ventilated image signal intensity (CV), a metric of regional ventilation heterogeneity. 1H steady-state free precession magnetic resonance images were separately acquired for assessment of lung morphology and mucus (15). [...]ventilation defects are present in children with PCD even in the presence of normal LCI and FEV1.

The volumetric flow rate (VFR) waveform over the cardiac cycle in the cerebral vasculature is a significant factor in many studies, which involve cerebrovascular function. Perhaps contrary to expectation, the literature in this area is sparse and the characteristics of blood flow waveforms are ill defined. A better understanding of the variation of blood flow rate and pulsatility may aid our knowledge of risk factors involved in diseases and conditions, such as stroke, arteriovenous malformation, or aneurysm rupture. This study sought to characterise the blood flow waveform over the cardiac cycle at levels within the carotid artery and basilar artery (BA) in a normal cohort. The study cohort consisted of 22 subjects (recruitment age: 20 to 40 years) with no history of vascular disease (median age=26 years, interquartile range=25 to 32 years). Two-dimensional quantitative phase-contrast magnetic resonance imaging was performed on each subject at nine anatomic locations within the carotid artery and BA. Significant differences in pulsatility were present within the carotid tree. Archetypal VFR waveforms were established for this group at the nine locations. A normal individual's VFR waveform at a location within the carotid tree can be estimated by taking the group's archetypal waveform for that location, and scaling by the individual's average flow rate.

ObjectivesTo determine the prognostic value of patterns of right ventricular adaptation in patients with pulmonary arterial hypertension (PAH), assessed using cardiac magnetic resonance (CMR) imaging at baseline and follow-up.MethodsPatients attending the Sheffield Pulmonary Vascular Disease Unit with suspected pulmonary hypertension were recruited into the ASPIRE (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral Centre) Registry. With exclusion of congenital heart disease, consecutive patients with PAH were followed up until the date of census or death. Right ventricular end-systolic volume index adjusted for age and sex and ventricular mass index were used to categorise patients into four different volume/mass groups: low-volume-low-mass, low-volume-high-mass, high-volume-low-mass and high-volume-high-mass. The prognostic value of the groups was assessed with one-way analysis of variance and Kaplan-Meier plots. Transition of the groups was studied.ResultsA total of 505 patients with PAH were identified, 239 (47.3%) of whom have died at follow-up (median 4.85 years, IQR 4.05). The mean age of the patients was 59±16 and 161 (32.7%) were male. Low-volume-low-mass was associated with CMR and right heart catheterisation metrics predictive of improved prognosis. There were 124 patients who underwent follow-up CMR (median 1.11 years, IQR 0.78). At both baseline and follow-up, the high-volume-low-mass group had worse prognosis than the low-volume-low-mass group (p<0.001). With PAH therapy, 73.5% of low-volume-low-mass patients remained in this group, whereas only 17.4% of high-volume-low-mass patients transitioned into low-volume-low-mass.ConclusionsRight ventricular adaptation assessed using CMR has prognostic value in patients with PAH. Patients with maladaptive remodelling (high-volume-low-mass) are at high risk of treatment failure.

AbstractEnd points that are repeatable and sensitive to change are important in pulmonary arterial hypertension (PAH) for clinical practice and trials of new therapies. In 42 patients with PAH, test–retest repeatability was assessed using the intraclass correlation coefficient and treatment effect size using Cohen’s d statistic. Intraclass correlation coefficients demonstrated excellent repeatability for MRI, 6 min walk test and log to base 10 N-terminal pro-brain natriuretic peptide (log10NT-proBNP). The treatment effect size for MRI-derived right ventricular ejection fraction was large (Cohen’s d 0.81), whereas the effect size for the 6 min walk test (Cohen’s d 0.22) and log10NT-proBNP (Cohen’s d 0.20) were fair. This study supports further evaluation of MRI as a non-invasive end point for clinical assessment and PAH therapy trials.Trial registration number NCT03841344.

RationaleAirways dysanapsis is defined by CT or spirometry as a mismatch between the size of the airways and lung volume and is associated with increased risk of developing chronic obstructive pulmonary disease (COPD). Lung disease in participants with dysanapsis and a label of asthma and/or COPD remains poorly understood.MethodsIn participants with asthma and/or COPD, we used 129Xe-MRI to assess ventilation, acinar dimensions and gas exchange, and pulmonary function tests, and compared people with spirometric dysanapsis (forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC)<−1.64 z and FEV1>−1.64 z) to those with normal spirometry (FEV1, FVC and FEV1/FVC>−1.64 z).ResultsFrom 165 participants assessed in the NOVELTY (NOVEL observational longiTudinal studY) ADPro (advanced diagnostic profiling) study with a physician-assigned diagnosis of asthma and/or COPD, 43 had spirometric dysanapsis and were age-matched to 43 participants with normal spirometry. Participants with dysanapsis had significantly increased ventilation defects (median difference (md) (95% CI) = 4.0% (1.42% to 5.38%), p<0.001), ventilation heterogeneity (md (95% CI) = 2.56% (1.31% to 3.56%), p<0.001) and measures of acinar dimensions (md (95% CI) = 0.004 cm2.s−1 (0.0009 to 0.007), p=0.009) from 129Xe-MRI, than those with normal spirometry. At the 1-year follow-up, only participants with dysanapsis had a significant increase in ventilation defects (md (95% CI)=0.45% (0.09% to 2.1%),p=0.016). Lower FEV1/FVC in the dysanapsis cohort was associated with increased ventilation defects (r=−0.64, R2=0.41, p<0.001) and increased acinar dimensions (r=−0.52, R2=0.38, p<0.001), with the highest values seen in those with an FVC above the upper limit of normal.ConclusionsParticipants with asthma and/or COPD, presenting to primary care with spirometric dysanapsis, exhibited increased lung abnormalities on 129Xe-MRI, when compared with those with normal spirometry. Spirometric dysanapsis in asthma and/or COPD is therefore associated with significant lung disease, and the FEV1/FVC is related to the degree of airways abnormality on 129Xe-MRI.

Airways dysanapsis is defined by CT or spirometry as a mismatch between the size of the airways and lung volume and is associated with increased risk of developing chronic obstructive pulmonary disease (COPD). Lung disease in participants with dysanapsis and a label of asthma and/or COPD remains poorly understood. In participants with asthma and/or COPD, we used Xe-MRI to assess ventilation, acinar dimensions and gas exchange, and pulmonary function tests, and compared people with spirometric dysanapsis (forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC)<-1.64 z and FEV1>-1.64 z) to those with normal spirometry (FEV1, FVC and FEV1/FVC>-1.64 z). From 165 participants assessed in the NOVELTY (NOVEL observational longiTudinal studY) ADPro (advanced diagnostic profiling) study with a physician-assigned diagnosis of asthma and/or COPD, 43 had spirometric dysanapsis and were age-matched to 43 participants with normal spirometry. Participants with dysanapsis had significantly increased ventilation defects (median difference (md) (95% CI) = 4.0% (1.42% to 5.38%), p<0.001), ventilation heterogeneity (md (95% CI) = 2.56% (1.31% to 3.56%), p<0.001) and measures of acinar dimensions (md (95% CI) = 0.004 cm .s (0.0009 to 0.007), p=0.009) from Xe-MRI, than those with normal spirometry. At the 1-year follow-up, only participants with dysanapsis had a significant increase in ventilation defects (md (95% CI)=0.45% (0.09% to 2.1%),p=0.016). Lower FEV1/FVC in the dysanapsis cohort was associated with increased ventilation defects (r=-0.64, R =0.41, p<0.001) and increased acinar dimensions (r=-0.52, R =0.38, p<0.001), with the highest values seen in those with an FVC above the upper limit of normal. Participants with asthma and/or COPD, presenting to primary care with spirometric dysanapsis, exhibited increased lung abnormalities on Xe-MRI, when compared with those with normal spirometry. Spirometric dysanapsis in asthma and/or COPD is therefore associated with significant lung disease, and the FEV1/FVC is related to the degree of airways abnormality on 129Xe-MRI.

Background. Four-dimensional flow cardiovascular magnetic resonance (4D flow CMR) is a noninvasive novel imaging technology that can be used to visualise and assess right ventricular function. The aim of this systematic review is to summarise the literature available on 4D flow CMR methods used to determine right ventricular diastolic function. Methods. A systematic review of current literature was carried out to ascertain what is known about right ventricular assessment by quantification of 4D flow CMR. Structured searches were carried out on Medline and EMBASE in December 2018. PG and NB screened the titles and abstracts for relevance. Results. Of the 20 articles screened, 5 studies met eligibility for systematic review. After a further search on pubmed 1 more relevant article was found and added to the review. Conclusions. These proposed methods using 4D flow CMR can quantify right ventricular diastolic assessment. The evidence gathered is mainly observational, featuring single-centred studies. Larger, multicentre studies are required to validate the proposed techniques, evaluate reproducibility, and investigate the clinical applicability that 4D flow CMR offers compared to standard practices. PROSPERO registration number is CRD42019121492.