Dynamic chest radiography for pulmonary vascular diseases: clinical applications and correlation with other imaging modalities

Dynamic chest radiography (DCR) is a novel functional radiographic imaging technique that can be used to visualize pulmonary perfusion without using contrast media. Although it has many advantages and clinical utility, most radiologists are unfamiliar with this technique because of its novelty. This review aims to (1) explain the basic principles of lung perfusion assessment using DCR, (2) discuss the advantages of DCR over other imaging modalities, and (3) review multiple specific clinical applications of DCR for pulmonary vascular diseases and compare them with other imaging modalities.

The Feasibility of Deep Learning-Based Reconstruction for Low-Tube-Voltage CT Angiography for Transcatheter Aortic Valve Implantation

OBJECTIVE

The purpose of this study is to evaluate the efficacy of deep learning reconstruction (DLR) on low-tube-voltage computed tomographic angiography (CTA) for transcatheter aortic valve implantation (TAVI).

METHODS

We enrolled 30 patients who underwent TAVI-CT on a 320-row CT scanner. Electrocardiogram-gated coronary CTA (CCTA) was performed at 100 kV, followed by nongated aortoiliac CTA at 80 kV using a single bolus of contrast material. We used hybrid-iterative reconstruction (HIR), model-based IR (MBIR), and DLR to reconstruct these images. The contrast-to-noise ratios (CNRs) were calculated. Five-point scales were used for the overall image quality analysis. The diameter of the aortic annulus was measured in each reconstructed image, and we compared the interobserver and intraobserver agreements.

RESULTS

In the CCTA, the CNR and image quality score for DLR were significantly higher than those for HIR and MBIR ( P < 0.01). In the aortoiliac CTA, the CNR for DLR was significantly higher than that for HIR ( P < 0.01) and significantly lower than that for MBIR ( P ≤ 0.02). The image quality score for DLR was significantly higher than that for HIR ( P < 0.01). No significant differences were observed between the image quality scores for DLR and MBIR. The measured aortic annulus diameter had high interobserver and intraobserver agreement regardless of the reconstruction method (all intraclass correlation coefficients, >0.89).

CONCLUSIONS

In low tube voltage TAVI-CT, DLR provides higher image quality than HIR, and DLR provides higher image quality than MBIR in CCTA and is visually comparable to MBIR in aortoiliac CTA.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Refined scan protocol for the evaluation of pulmonary perfusion standardized image quality and reduced radiation dose in dynamic chest radiography

PURPOSE

Dynamic chest radiography (DCR) is a novel imaging technique used to noninvasively evaluate pulmonary perfusion. However, the standard DCR protocol, which is roughly adapted to the patient's body size, occasionally causes over- or underexposure, which could influence clinical evaluation. Therefore, we proposed a refined protocol by increasing the number of patient body mass index (BMI) categories from three to seven groups and verified its usefulness by comparing the image sensitivity indicators (S-values) and entrance surface doses (ESDs) of the conventional protocol with those of our refined protocol.

METHODS

This retrospective observational study included 388 datasets (standing position, 224; supine position, 164) for the conventional protocol (December 2019-April 2021) and 336 datasets (standing position, 233; supine position, 103) for the refined protocol (June-November 2021). The conventional protocol (BMI-3 protocol) divided the patients into three BMI groups (BMI < 17, 17≤BMI < 25, and BMI ≥ 25 kg/m2 ), whereas the refined protocol (BMI-7 protocol) divided the patients into seven BMI groups (BMI < 17, 17 ≤ BMI < 20, 20 ≤ BMI < 23, 23 ≤ BMI < 26, 26 ≤ BMI < 29, 29 ≤ BMI < 32, and BMI ≥ 32 kg/m2 ). The coefficients of variation (CVs) for the S-values and ESDs acquired using the two protocols were compared.

RESULTS

The CVs of the S-values in the BMI-7 protocol group were significantly lower than those in the BMI-3 protocol group for the standing (28.8% vs. 16.7%; p < 0.01) and supine (24.5% vs. 17.7%; p < 0.01) positions. The ESDs of patients scanned using the BMI-7 protocol were significantly lower than those scanned using the BMI-3 protocol in the standing (1.3 vs. 1.1 mGy; p < 0.01) and supine positions (2.5 vs. 1.6 mGy; p < 0.01), although the mean BMI of the two groups were similar.

CONCLUSION

We introduced the BMI-7 protocol and demonstrated its standardized image quality and reduced radiation exposure in patients undergoing DCR.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Correlation Between Contrast-Detail Analysis and Clinical Image Quality Assessment of Intrapulmonary Lesions in Dual-Energy Subtraction Chest Radiography Using the Two-Shot Method: A Phantom Study

RATIONALE AND OBJECTIVES

Dual-energy subtraction (DES) imaging constitutes a technique that has demonstrated efficacy in enhancing the detectability of pulmonary nodules on chest radiographs. However, a simple and quantitative methodology for evaluating the clinical image quality of DES images is currently lacking. The objective of this study was to investigate the applicability of contrast-detail (C-D) phantom analysis to the visual clinical image quality evaluation of chest DES images.

MATERIALS AND METHODS

We employed a custom-made phantom incorporating the C-D phantom and a multipurpose anthropomorphic adult chest phantom. Two phantom sizes were utilized to simulate standard- and large-bodied adult patients for each phantom. The custom-made phantom images were scored automatically using dedicated software, yielding an inverse image quality figure (IQFinv) value. The multipurpose anthropomorphic adult chest phantom was employed in a visual grading analysis (VGA) study that was conducted by two experienced radiologists and five radiological technologists. Each nodule placed in the chest phantom image was rated on a 4-point Likert scale.

RESULTS

A statistically significant correlation was observed between the VGA scores of the seven observers and the obtained IQFinv values.

CONCLUSION

The findings of this study suggest that DES image analysis of the C-D phantom possesses the potential to be utilized for the evaluation of clinical DES image quality based on chest lesion detectability.

Technical Considerations for Performing Safe and Effective Balloon Pulmonary Angioplasty in Patients with Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a late complication of acute pulmonary thromboembolism owing to incomplete clot dissolution in pulmonary artery. Pulmonary endarterectomy is the first-line treatment for CTEPH. However, 40% of patients are not candidates for surgery because of distal lesions or age. Balloon pulmonary angioplasty (BPA), a catheter-based intervention, is increasingly being used worldwide for treating inoperable CTEPH. Previous BPA strategy had a major concern of reperfusion pulmonary edema as a complication. However, recent refined strategies promise safe and effective BPA. Five-year survival rate after BPA is 90% for inoperable CTEPH, comparable with that of operable CTEPH.

Efficacy of Dynamic Chest Radiography for Chronic Thromboembolic Pulmonary Hypertension

Background While current guidelines require lung ventilation-perfusion (V/Q) scanning as the first step to diagnose chronic pulmonary embolism in pulmonary hypertension (PH), its use may be limited by low availability and/or exposure to ionizing radiation. Purpose To compare the performance of dynamic chest radiography (DCR) and lung V/Q scanning for detection of chronic thromboembolic PH (CTEPH). Materials and Methods Patients with PH who underwent DCR and V/Q scanning in the supine position from December 2019 to July 2021 were retrospectively screened. The diagnosis of CTEPH was confirmed with right heart catheterization and invasive pulmonary angiography. Observer tests were conducted to evaluate the diagnostic accuracy of DCR and V/Q scanning. The lungs were divided into six areas (upper, middle, and lower for both) in the anteroposterior image, and the number of lung areas with thromboembolic perfusion defects was scored. Diagnostic performance was compared between DCR and V/Q scanning using the area under the receiver operating characteristic curve. Agreement between the interpretation of DCR and that of V/Q scanning was assessed using the Cohen kappa coefficient and percent agreement. Results A total of 50 patients with PH were analyzed: 29 with CTEPH (mean age, 64 years ± 15 [SD]; 19 women) and 21 without CTEPH (mean age, 61 years ± 22; 14 women). The sensitivity, specificity, and accuracy of DCR were 97%, 86%, and 92%, respectively, and those of V/Q scanning were 100%, 86%, and 94%, respectively. Areas under the receiver operating characteristic curve for DCR and V/Q scanning were 0.92 (95% CI: 0.79, 0.97) and 0.93 (95% CI: 0.78, 0.98). Agreement between the consensus interpretation of DCR and that of V/Q scanning was substantial (κ = 0.79 [95% CI: 0.61, 0.96], percent agreement = 0.9 [95% CI: 0.79, 0.95]). Conclusion Dynamic chest radiography had similar efficacy to ventilation-perfusion scanning in the detection of chronic thromboembolic pulmonary hypertension. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Wandtke and Koproth-Joslin in this issue.

Visibility of Pulmonary Valve and Pulmonary Regurgitation on Intracardiac Echocardiography in Adult Patients with Tetralogy of Fallot

Pulmonary regurgitation (PR) is a risk factor for sudden cardiac death in adult patients with repaired tetralogy of Fallot (TOF). However, transthoracic echocardiography (TTE) cannot fully visualize the pulmonary valve (PV) and PR. We investigated whether intracardiac echocardiography (ICE) could visualize the PV and PR better than TTE. Thirty adult patients with TOF (mean age 33 ± 15 years) scheduled for cardiac catheterization underwent ICE. The visualization of PV and the severity of PR were classified into three grades. ICE depicted the PV better than TTE (ICE vs. TTE: not visualized, partially visualized, and fully visualized: n = 1 [3%], n = 13 [43%], and n = 16 [53%] vs. n = 14 [47%], n = 13 [43%], and n = 3 [10%], p < 0.001). Especially in patients after pulmonary valve replacement (PVR), the PV was more fully visualized by ICE. The assessment of PR by TTE underestimated the severity of PR in comparison to cardiac magnetic resonance imaging (MRI) (severe PR: 8 [28%] vs. 22 [76%], p = 0.004), while there was no discrepancy between the results of ICE and MRI (21 [72%] vs. 22 [76%], p = 1.000). In comparison to TTE, ICE can safely provide better visualization of the PV and PR in adults with TOF, especially in patients who have undergone PVR.

Right ventricular strain and volume analyses through deep learning-based fully automatic segmentation based on radial long-axis reconstruction of short-axis cine magnetic resonance images

OBJECTIVE

We propose a deep learning-based fully automatic right ventricle (RV) segmentation technique that targets radially reconstructed long-axis (RLA) images of the center of the RV region in routine short axis (SA) cardiovascular magnetic resonance (CMR) images. Accordingly, the purpose of this study is to compare the accuracy of deep learning-based fully automatic segmentation of RLA images with the accuracy of conventional deep learning-based segmentation in SA orientation in terms of the measurements of RV strain parameters.

MATERIALS AND METHODS

We compared the accuracies of the above-mentioned methods in RV segmentations and in measuring RV strain parameters by Dice similarity coefficients (DSCs) and correlation coefficients.

RESULTS

DSC of RV segmentation of the RLA method exhibited a higher value than those of the conventional SA methods (0.84 vs. 0.61). Correlation coefficient with respect to manual RV strain measurements in the fully automatic RLA were superior to those in SA measurements (0.5-0.7 vs. 0.1-0.2).

DISCUSSION

Our proposed RLA realizes accurate fully automatic extraction of the entire RV region from an available CMR cine image without any additional imaging. Our findings overcome the complexity of image analysis in CMR without the limitations of the RV visualization in echocardiography.

High-resolution systolic T1 mapping with compressed sensing for the evaluation of the right ventricle: a phantom and volunteer study

To investigate the usefulness of high-resolution systolic T1 mapping using compressed sensing for right ventricular (RV) evaluation. Phantoms and normal volunteers were scanned at 3 T by using a high-resolution (HR) modified look-locker inversion recovery (MOLLI) pulse sequence and a conventional MOLLI pulse sequence. The T1 values of the left ventricular (LV) and RV myocardium and blood pool were measured for each sequence. T1 values of HR-MOLLI and MOLLI sequences were compared in the LV myocardium, blood pool, and RV myocardium. The T1 values of HR-MOLLI and MOLLI showed good agreement in both phantoms and the LV myocardium and blood pool of volunteers. However, there was a significant difference between HR-MOLLI and MOLLI in the RV myocardium (1258 ± 52 ms vs. 1327 ± 73 ms; P = 0.0005). No significant difference was observed between the T1 value of RV and that of LV (1217 ± 32 ms) in HR-MOLLI, whereas the T1 value of RV was significantly higher than that of LV in MOLLI (P < 0.0001). The interclass correlation coefficients of intraobserver variabilities from HR-MOLLI and MOLLI were 0.919 and 0.804, respectively, and the interobserver variabilities from HR-MOLLI and MOLLI were 0.838 and 0.848, respectively. Assessment of RV myocardium by using HR systolic T1 mapping was superior to the conventional MOLLI sequence in terms of accuracy and reproducibility.

Dynamic Chest Radiography of Acute Pulmonary Thromboembolism

Supplemental material is available for this article.

Is the image quality of conventional chest radiography obtained from a two-layer flat panel detector affected by the internal structure of the detector?

PURPOSE

Recently developed and commercialized dual-layer flat panel detectors (DL-FPDs) with two indirect scintillators are capable of acquiring dual-energy X-ray images. However, in clinical practice, they are utilized to perform conventional radiography using diagnostic X-rays with a wide energy spectrum. The two layers of the DL-FPD may affect the obtained image quality, even when only using one layer for conventional image acquisition, and these effects are yet to be substantiated. Therefore, in this study, we quantitatively evaluated the image quality of a conventional chest radiography using DL-FPD and visually verified the characteristics of the chest anthropomorphic phantom images.

METHODS

The physical characteristics of the system were evaluated using the pre-sampled modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE), for beam quality RQA 7 and RQA 9. In addition, the subjective visibility of the anthropomorphic chest phantom and simple objects images were compared with those of a conventional single-layer flat-panel detector (SL-FPD).

RESULTS

No significant differences were found in the MTF between the SL-FPD and DL-FPD images. In addition, a higher DQE was observed at some exposure doses and in the high spatial frequency regions wherein NNPSs were lower for DL-FPD than for SL-FPD. Furthermore, no significant differences were found in the subjective visibility of the chest phantoms in each system.

CONCLUSIONS

We concluded that the image quality of the conventional radiography acquired with DL-FPD is comparable to or better than that of the SL-FPD.

Evaluation of MR imaging findings differentiating parotid basal cell adenomas from other parotid tumors

PURPOSE

To evaluate the usefulness of magnetic resonance imaging (MRI) to differentiate basal cell adenomas (BCAs) from other parotid tumors.

METHOD

A total of 136 patients with histologically proven parotid gland tumors (13 BCAs, 66 pleomorphic adenomas [PAs], 30 Warthin tumors [WTs], and 27 parotid cancers [PCs]) who underwent a cervical MRI study between December 2011 and March 2019 were retrospectively enrolled. The MRI findings of the tumors were evaluated by two board-certified radiologists.

RESULTS

All 13 of the BCAs showed smooth margins, while 19 of the 27 PCs showed irregular margins (p < 0.0001). Eleven BCAs had some cystic components, and five were cyst-dominant. The BCAs had significantly more cystic components than the PAs (p = 0.0077). The mean apparent diffusion coefficient (ADC) value of the BCAs was 1.21 ± 0.20 × 10^-3 mm²/sec, which was equivalent to that of the PCs (1.12 ± 0.25 × 10^-3 mm²/sec, p = 0.76), significantly lower than that of the PAs (1.61 ± 0.32 × 10^-3 mm²/sec, p < 0.0001), and significantly higher than that of the WTs (0.81 ± 0.19 × 10^-3 mm²/sec, p = 0.0004). The plateau time-intensity curve (TIC) was the most common type for both BCAs and PCs, seen in 8 of 12 BCAs and 21 of 26 PCs, with no significant difference between these groups (p = 0.34).

CONCLUSIONS

BCA should be considered a possibility when a parotid lesion has smooth margins with an entire capsule and includes a cystic component, even if the TIC and diffusion-weighted MR images suggest a malignant pattern.

Model-based iterative reconstruction for 320-detector row CT angiography reduces radiation exposure in infants with complex congenital heart disease

PURPOSE

We investigated the impact of model-based iterative reconstruction (MBIR) on 320-detector row computed tomography angiography (CTA) in infants with complex congenital heart disease (CHD).

METHODS

Seventy infants with complex CHD who underwent 320-detector row CTA (40 boys and 30 girls; age range, 0-22 months; median age, 60 days) were retrospectively evaluated. First, the images were reconstructed by filtered back projection (FBP), hybrid iterative reconstruction (HIR), or MBIR in 20 cases, and variables were compared among the three iterative reconstruction methods (IR test). Second, the variables were compared between 25 cases scanned using HIR and 25 cases scanned using MBIR, with a 20 standard deviation noise level for both. Attenuation values and contrast-to-noise ratios (CNRs) of the great vessels and heart chambers were calculated. Total dose-length products were recorded for all patients (radiation dose: RD test).

RESULTS

In the IR test, the mean CNR values were 4.8±1.3 for FBP, 6.9±1.4 for HIR, and 8.2±1.7 for MBIR (P < 0.0001). The best subjective image qualities in the great vessels and heart chambers were obtained with MBIR. In RD testing, no significant differences between HIR and MBIR in image quality (CNR: HIR, 8.4±2.4; MBIR, 8.3±2.4) were observed. The effective dose was significantly lower for MBIR than for HIR (0.7±0.2 vs. 1.1±0.3 mSv; P < 0.001).

CONCLUSION

The MBIR algorithm significantly improved image quality and decreased radiation exposure in 320-row CTA of infants with complex CHD, providing an alternative to FBP or HIR that is both safer and produces better results.

AB0436 OUTCOMES OF DOSE-REDUCTION OR DISCONTINUATION OF TOCILIZUMAB IN PATIENTS WITH EARLY DIFFUSE CUTANEOUS SYSTEMIC SCLEROSIS

Background:

Potential efficacy and favorable safety profiles of tocilizumab (TCZ) have been demonstrated in patients with diffuse cutaneous systemic sclerosis (dcSSc) [1, 2]. However, clinical outcomes after dose-reduction or discontinuation of TCZ due to an improvement of skin thickness remain unclear.

Objectives:

To investigate the clinical outcomes after dose-reduction or discontinuation of TCZ in patients with dcSSc in a real-world setting.

Methods:

This is a single-center, retrospective, observational study using a database of consecutive SSc patients who visited our center between April 2014 and October 2020. For this study, we selected eligible patients from the database based on the following criteria: patients who (i) fulfilled the ACR/EULAR classification criteria, (ii) were classified as having dcSSc, (iii) had been treated with TCZ for at least 6 months, and (iv) were follow-up >6 months after TCZ introduction. Clinical information including demographic and clinical characteristics at TCZ introduction; dosing, administration route, and adherence of TCZ; and serial clinical parameters (modified Rondan total skin thickness score [mRSS], and percent predicted forced vital capacity [%FVC]), safety profiles, and outcomes after TCZ introduction regardless of TCZ continuation were extracted from the database.

Results:

Of 404 patients enrolled in the database, 13 dcSSc patients were eligible for this study. Baseline characteristics included a mean age of 51 ± 9 years, 85% female, disease duration of 27 ± 24 months, and mRSS of 19.5 ± 10.6. Seven patients (54%) had HRCT-confirmed ILD at baseline, and 9 (69%) were positive for anti-topoisomerase I antibody. Two (14%) and 11 (85%) were on mycophenolate mofetil and low-dose prednisolone (7.2 ± 6.0 mg/day), respectively. Seven patients (54%) each had active skin disease and elevated inflammatory markers defined in the phase III clinical trial [2], while only 4 (31%) fulfilled the inclusion criteria. TCZ was initially administered intravenously (8 mg/kg every 4 weeks) in 8 patients and subcutaneously in 5 (162 mg every 2 weeks in 4 and every week in one). At one year, mRSS was improved from 20.9 ± 11.4 to 10.7 ± 8.9 in 11 patients (p = 0.007), and %FVC was stable in 7 patients with ILD (76.8 ± 15.0 to 78.6 ± 16.1). During the observation period of 60.4 ± 26.7 months, 4 patients were treated with a stable dose of TCZ, while TCZ dose was reduced and/or discontinued in 9. Four of them discontinued TCZ due to adverse events (n = 2; acute lung injury and phlegmon) or prominent improvement of skin thickening (n = 2). Of 9 patients with dose reduction/discontinuation of TCZ, 4 patients who discontinued TCZ (n = 3) or received dose reduction of TCZ (n = 1) experienced a recurrence of progressive skin thickening together with inflammatory complications, including edematous induration of the skin, progression of ILD, polyarthritis, and/or pericarditis with increased inflammatory markers. The interval between dose-reduction/discontinuation of TCZ and clinical worsening ranged from 2 to 11 months. These manifestations were promptly improved by dose-escalation or resumption of TCZ in all patients except one who experienced progressive ILD and died of respiratory failure 27 months later.

Conclusion:

In dcSSc patients who experienced improvement of skin thickness during treatment with TCZ, dose-reduction or discontinuation of TCZ may result in a recurrence of the disease. Randomized comparative studies are necessary to examine optimal timing for dose-reduction or discontinuation of TCZ in dcSSc patients after improvement of skin thickness.

References:

[1]Khanna, D., et al., Safety and efficacy of subcutaneous tocilizumab in systemic sclerosis: results from the open-label period of a phase II randomised controlled trial (faSScinate). Ann Rheum Dis, 2018. 77(2):212-220.

[2]Khanna, D., et al., Tocilizumab in systemic sclerosis: a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Respir Med, 2020; 8(10): 963-974.

Disclosure of Interests:

Yohei Isomura: None declared, Yoshioki Yamasaki Speakers bureau: Boehringer-Ingelheim, Nippon Shinyaku, Bristol Myers, Yuichiro Shirai Speakers bureau: Janssen, Grant/research support from: Janssen, Masataka Kuwana Speakers bureau: Abbie, Astellas, Asahi Kasei Parma, Boehringer-Ingelheim, Chugai, Eisai, Janssen, MBL, Mochida, Nippon Shinyaku, Ono Pharmaceuticals, Pfizer, Tanabe-Mitsubishi, Consultant of: Boehringer-Ingelheim, Chugai, Corbus, MBL, Mochida, Grant/research support from: Boehringer-Ingelheim, Chugai, Eisai, MBL, Ono Pharmaceuticals, Tanabe-Mitsubishi

Dynamic Chest Radiography of Pulmonary Arteriovenous Malformation

Online supplemental material is available for this article.

Usefulness of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnosis of Infective Endocarditis in Patients With Adult Congenital Heart Disease

BACKGROUND

Infective endocarditis (IE) in patients with adult congenital heart disease (ACHD) remains a diagnostic challenge due to difficulties in detecting endocardial lesions by echocardiography. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) has shown good diagnostic performance in prosthetic valve IE. This study aimed to assess its additional diagnostic value in ACHD-associated IE and to characterize its advantages.Methods and Results:Overall, 22 patients with ACHD and clinical suspicion of IE were retrospectively studied. ¹⁸F-FDG PET/CT was performed in addition to conventional assessment based on the modified Duke criteria. The final IE diagnosis was determined by an expert team during a 3-month clinical course, resulting in 18 patients diagnosed with IE. Seven patients (39%) were diagnosed with definite IE only by initial echocardiography. An ¹⁸F-FDG PET/CT assessment revealed endocardial involvement in the other 9 patients, resulting in the diagnosis of definite IE in 16 in total (88%). Right-sided endocardial lesions were more common (n=12, 67%) but rarely identified by echocardiography, whereas ¹⁸F-FDG PET/CT revealed right-sided lesions in 9 patients. A negative ¹⁸F-FDG PET/CT (n=7, 39%) assessment was associated with a native valve IE (71% vs. 0%). In 4 patients who were identified with not-IE, neither echocardiography nor ¹⁸F-FDG PET/CT detected any suspicious cardiac involvement.

CONCLUSIONS

In the diagnosis of ACHD-associated IE, characterized by right-sided IE, ¹⁸F-FDG PET/CT assessment should be useful.

Right Ventricular Extracellular Volume with Dual-Layer Spectral Detector CT: Value in Chronic Thromboembolic Pulmonary Hypertension

Background Right ventricular (RV) extracellular volumes (ECVs), as a surrogate for histologic fibrosis, have not been sufficiently investigated. Purpose To evaluate and compare RV and left ventricular (LV) ECVs obtained with dual-layer spectral detector CT (DLCT) in chronic thromboembolic pulmonary hypertension (CTEPH) and investigate the clinical importance of RV ECV. Materials and Methods Retrospective analysis was performed on data from 31 patients with CTEPH (17 were not treated with pulmonary endarterectomy [PEA] or balloon pulmonary angioplasty [BPA] and 14 were) and eight control subjects who underwent myocardial delayed enhancement (MDE) DLCT from January 2019 to June 2020. The ECVs in the RV and LV walls were calculated by using iodine density as derived from spectral data pertaining to MDE. Statistical analyses were performed with one-way repeated analysis of variance with the Tukey post hoc test or the Kruskal-Wallis test with the Steel-Dwass test and linear regression analysis. Results The PEA- and BPA-naive group showed significantly higher ECVs than the PEA- or BPA-treated group and control group in the septum (28.2% ± 2.9 vs 24.3% ± 3.6, P = .005), anterior right ventricular insertion point (RVIP) (32.9% ± 4.6 vs 25.3% ± 3.6, P < .001), posterior RVIP (35.2% ± 5.2 vs 27.3% ± 4.2, P < .001), mean RVIP (34.0% ± 4.2 vs 26.3% ± 3.4, P < .001), RV free wall (29.5% ± 3.3 vs 25.9% ± 4.1, P = .036), and mean RV wall (29.1% ± 3.0 vs 26.1% ± 3.1, P = .029). There were no significant differences between the PEA- or BPA-treated group and control subjects in these segments (septum, P = .93; anterior RVIP, P = .38; posterior RVIP, P = .52; mean RVIP, P = .36; RV free wall, P = .97; and mean RV, P = .33). There were significant correlations between ECV and mean pulmonary artery pressure (PAP) or brain natriuretic peptide (BNP) in the mean RVIP (mean PAP: R = 0.66, P < .001; BNP: R = 0.44, P = .014) and the mean RV (mean PAP: R = 0.49, P = .005; BNP: R = 0.44, P = .013). Conclusion Right ventricular and right ventricular insertion point extracellular volumes could be noninvasive surrogate markers of disease severity and reverse tissue remodeling in chronic thromboembolic pulmonary hypertension. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Sandfort and Bluemke in this issue.

Topological metastability supported by thermal fluctuation upon formation of chiral soliton lattice in [Formula: see text]

Topological magnetic structure possesses topological stability characteristics that make it robust against disturbances which are a big advantage for data processing or storage devices of spintronics; nonetheless, such characteristics have been rarely clarified. This paper focused on the formation of chiral soliton lattice (CSL), a one-dimensional topological magnetic structure, and provides a discussion of its topological stability and influence of thermal fluctuation. Herein, CSL responses against change of temperature and applied magnetic field were investigated via small-angle resonant soft X-ray scattering in chromium niobium sulfide ([Formula: see text]). CSL transformation relative to the applied magnetic field demonstrated a clear agreement with the theoretical prediction of the sine-Gordon model. Further, there were apparent differences in the process of chiral soliton creation and annihilation, discussed from the viewpoint of competing between thermal fluctuation and the topological metastability.

New transluminal attenuation gradient derived from dynamic coronary CT angiography: diagnostic ability of ischemia detected by 13N-ammonia PET

Coronary computed tomography angiography (CCTA) has low specificity for detecting significant functional coronary stenosis. We developed a new transluminal attenuation gradient (TAG)-derived dynamic CCTA with dose modulation, and we investigated its diagnostic performance for myocardial ischemia depicted by ¹³N-ammonia positron emission tomography (PET). Data from 48 consecutive patients who had undergone both dynamic CCTA and ¹³N-ammonia PET were retrospectively analyzed. Dynamic CCTA was continuously performed in mid-diastole for five cardiac cycles with prospective electrocardiography gating after a 10-s contrast medium injection. One scan of the dynamic CCTA was performed as a boost scan for conventional CCTA at the peak phase of the ascending aorta. Absolute TAG values at five phases around the boost scan were calculated. The dynamic TAG index (DTI) was defined as the ratio of the maximum absolute TAG to the standard deviation of five TAG values. We categorized the coronary territories as non-ischemia or ischemia based on the ¹³N-ammonia PET results. A receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff of the DTI for identifying ischemia. The DTI was significantly higher for ischemia compared to non-ischemia (8.8 ± 3.9 vs. 4.6 ± 2.0, p < 0.01). The ROC analysis revealed 5.60 as the optimal DTI cutoff to detect ischemia, with an area under the curve of 0.87, 85.7% sensitivity, and 76.2% specificity. TAG provided no additional diagnostic value for the detection of ischemia. We propose the DTI derived from dynamic CCTA as a novel coronary flow index. The DTI is a valid technique for detecting functional coronary stenosis.

Balloon pulmonary angioplasty improves right atrial reservoir and conduit functions in chronic thromboembolic pulmonary hypertension

AIMS

Right atrial (RA) function largely contributes to the maintenance of right ventricular (RV) function. This study investigated the effect of balloon pulmonary angioplasty (BPA) on RA functions in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) using cardiac magnetic resonance imaging (CMRI).

METHODS AND RESULTS

CMRI and RV catheterization were performed before BPA sessions and at the follow-up periods in 29 CTEPH patients. Reservoir [RA longitudinal strain (RA-LS)], passive conduit [RA early LS rate (LSR)], and active (RA late LSR) phases were assessed by using cine CMRI and a feature-tracking algorithm. The relationships between the changes in RA functions and in brain natriuretic peptide (BNP) were evaluated in both the dilated and non-dilated RA groups. RA-LS (32.4% vs. 42.7%), RA LSR (6.3% vs. 8.3%), and RA early LSR (-2.3% vs. -4.3%) were improved after BPA, whereas no significant change was seen in RA late LSR. The changes in RA peak LS and in RA early LSR were significantly correlated with the changes in BNP (ΔRA-LS: r = -0.63, ΔRA-early LSR: r = 0.65) and pulmonary vascular resistance (PVR) (ΔRA-LS: r = -0.69, ΔRA-early LSR: r = 0.66) in the nondilated RA group.

CONCLUSION

The RA reservoir and passive conduit functions were impaired in inoperable CTEPH, whereas RA active function was preserved. BPA markedly reversed these impaired functions. The improvements in RA reservoir and conduit functions were significantly correlated with the changes in BNP levels and PVR in CTEPH patients with normal RA sizes.

Preoperative Threshold for Normalizing Right Ventricular Volume After Transcatheter Closure of Adult Atrial Septal Defect

BACKGROUND

The latest guidelines recommend early intervention in adult atrial septal defect (ASD) patients with signs of right ventricular (RV) enlargement. However, the criteria of RV enlargement for optimal intervention remain unclear. We investigated the preoperative determinants for normalizing the RV volume after transcatheter closure of ASD in adults.Methods and Results:We retrospectively analyzed 52 ASD patients who underwent transcatheter closure. Cardiac magnetic resonance imaging (CMR) measured RV volume before and 1 year after the closure. The patients were divided into normalized (postoperative RV end-systolic volume index [RVESVI] <47 mL/m²and end-diastolic volume index [RVEDVI] <108 mL/m²) and non-normalized (postoperative RVESVI ≥47 mL/m²or RVEDVI ≥108 mL/m²) groups. Preoperative RVESVI was significantly smaller (72 mL/m²vs. 80 mL/m²) and RVEF was higher (56% vs. 51%) in the normalized group compared with the non-normalized group. Receiver-operating characteristic analysis for the normalization of postoperative RV volume showed that the preoperative threshold value of RVESVI was 75 mL/m². In addition, multivariate analysis showed that preoperative RVESVI was an independent predictor for normalization of RV volume.

CONCLUSIONS

Preoperative RVESVI is an independent predictor for normalization of RV volume at 1 year after transcatheter closure of ASD in adults. Early intervention before RVESVI reaches 75 mL/m²may confer optimal timing for normalizing RV volume.

Amide proton transfer (APT) imaging of parotid tumors: Differentiation of malignant and benign tumors

PURPOSE

To assess the usefulness of amide proton transfer (APT) imaging in differentiating parotid tumors.

MATERIAL AND METHODS

We retrospectively analyzed 43 histopathologically proven parotid solid tumors with diameters ≥2 cm. Twenty-one tumors were benign and 12 tumors were malignant. Two-dimensional APT imaging was performed using a saturation pulse with a duration of 2 s and a saturation power level of 2 μT. For acquiring Z-spectra, the imaging was repeated at 25 saturation frequency offsets from ω = -6 to +6 ppm with a step of 0.5 ppm as well as one scan acquired far off-resonance (-1560 ppm) for signal normalization. For the APT imaging, the asymmetry analysis at 3.5 ppm downfield from the water signal was calculated. The mean APT signal intensity (SI) was compared between the benign and malignant tumors.

RESULTS

The mean APT SI was 2.23 ± 0.80 % in the benign tumors and significantly higher at 2.99 ± 0.99 % in the malignant tumors (P = 0.01). A receiver operating curve analysis revealed that the optimal APT SI threshold was 2.40 for distinguishing malignant tumors from benign tumors with an area under the curve of 0.74. The sensitivity, specificity, and accuracy were 83.3%, 61.3%, and 67.4%, respectively.

CONCLUSION

The mean APT SI of the malignant parotid tumors was significantly higher than that of the benign parotid tumors.

Frequency and Significance of Coronary Artery Disease and Myocardial Bridging in Patients With Hypertrophic Cardiomyopathy

The etiology of chest pain in hypertrophic cardiomyopathy (HC) is diverse and includes coronary artery disease (CAD) as well as HC-specific causes. Myocardial bridging (MB) has been associated with HC, chest pain, and accelerated atherosclerosis. We compared HC patients with age-, gender- and CAD pre-test probability-matched outpatients presenting with chest pain to investigate differences in the presence of MB and CAD using coronary computed tomography angiography (CCTA). We studied 84 HC patients who underwent CCTA and compared these with 168 matched controls (age 54 ± 11 years, 70% men, pre-test probability 12% [5% to 32%]). MB, calcium score, plaque morphology and presence and extent of CAD were assessed for each patient. Linear mixed models were used to assess differences between cases and controls. MB was more often seen in HC patients (50% vs 25%, p <0.001). Calcium score and the presence of obstructive CAD were similar in both groups (9 [0 to 225] vs 4 [0 to 82] and 18% vs 19%; p = 0.22 and p = 0.82). In the HC group, MB was associated with pathogenic DNA variants (p = 0.04), but not with the presence of chest pain (74% vs 76%, p = 0.8), nor with worse outcome (log-rank p = 0.30). In conclusion, the prevalence and extent of CAD was equal among patients with and without HC, demonstrating that pre-test risk prediction using the CAD Consortium clinical risk score performs well in HC patients. MB was twice as prevalent in the HC group compared with matched controls, but was not associated with chest pain or decreased event-free survival in these patients.

Detectability of the artery of Adamkiewicz on computed tomography angiography of the aorta by using ultra-high-resolution computed tomography

PURPOSE

To evaluate the detectability of AKA on aortic computed tomography angiography (CTA) using ultra-high-resolution computed tomography (UHRCT).

MATERIALS AND METHODS

Twenty-eight patients were enrolled. They underwent aortic CTA with UHRCT (UHRCTA) and had previously undergone aortic conventional CTA (CCTA). The injection protocol of UHRCTA was the same as that of CCTA. The bolus tracking technique was used. UHRCTA images were reconstructed with adaptive iterative dose reduction (strong) and with forward-projected model-based iterative reconstruction solution. The matrix size and slice thickness on UHRCT were 1024 and 0.25 mm, respectively, and those on conventional CT were 512 and 0.5 or 0.67 mm, respectively. The UHRCTA and CCTA images were visually compared by using four scales. A score of 4 or 3 indicated that the AKA was assessable. In this instance, the contrast-to-noise ratios of each UHRCTA were measured. The exposure dose and signal-to-noise ratios were also investigated.

RESULTS

The AKA visualization scores obtained with UHRCTA with forward-projected model-based iterative reconstruction solution were significantly higher than those with adaptive iterative dose reduction (p = 0.018) and CCTA (p = 0.0024).

CONCLUSION

UHRCT can contribute to the better visualization of the AKA on aortic CTA.

Correction to: Development of a new phantom simulating extracellular space of tumor cell growth and cell edema for diffusion-weighted magnetic resonance imaging

The original version of this article unfortunately contained a mistake. Second column of "Cell edema" should read as.

Low Radiation Dose and High Image Quality of 320-Row Coronary Computed Tomography Angiography Using a Small Dose of Contrast Medium and Refined Scan Timing Prediction

OBJECTIVE

The aim of the study was to investigate the feasibility of coronary computed tomography (CT) angiography with a low kilovoltage peak scan and a refined scan timing prediction using a small contrast medium (CM) dose.

METHODS

In protocol A, 120-kVp scanning and a standard CM dose were used. The scan timing was fixed. In protocol B, 80 kVp and a 60% CM dose were used. The scan timing was determined according to the interval from the CM arrival to the peak time in the ascending aorta. We measured the CT number and recorded the radiation dose.

RESULTS

Higher CT numbers were observed in the left circumflex (proximal, P = 0.0235; middle, P = 0.0007; distal, P < 0.0001) in protocol B compared with protocol A. The radiation dose in protocol B was significantly lower than in protocol A (2.2 ± 0.9 vs 4.3 ± 1.7 mSv).

CONCLUSIONS

Low-contrast, low-radiation dose, high-image quality coronary CT angiography can be performed with low kilovoltage peak scanning and a refined scan timing prediction.

P1825 Myocardial bridging and coronary artery disease in hypertrophic cardiomyopathy: a matched case control study

Funding Acknowledgements

None.

Introduction

The etiology of chest pain in hypertrophic cardiomyopathy (HCM) is diverse and includes coronary artery disease (CAD) as well as HCM-specific causes. Myocardial bridging (MB) has been associated with HCM, chest pain, and accelerated atherosclerosis. To investigate differences in the presence of MB and CAD, we compared HCM patients with age-, gender- and CAD pre-test probability (PTP)-matched outpatients presenting with chest pain.

Methods

We studied 84 HCM patients who underwent cardiac computed tomography and compared these with 168 matched controls (age 54 ± 11 years, 70% men, PTP 12% [5%–32%]). MB, calcium score, plaque morphology and presence and extent of CAD were assessed for each patient. Linear mixed models were used to assess differences between cases and controls.

Results

Differences between HCM patients and controls are described in the table. In summary, MB was more often seen in HCM patients (50% vs. 25%, p &lt; 0.001), who were also more likely to have &gt;1 segment affected (14% vs. 2%, p &lt; 0.05). In the HCM group, MB was associated with pathogenic mutation status. Calcium score and the presence of obstructive CAD were similar in both groups (9 [0-225] vs. 4 [0-82] and 18% vs. 19%; p &gt; 0.05 for both).

Conclusion

MB was twice as prevalent in the HCM group. However, in a matched analysis, the prevalence and extent of CAD was equal among patients with and without HCM. These finding illustrate that despite a higher prevalence of MB, the prevalence of CAD is similar between groups, also demonstrating satisfactory performance of pre-test risk prediction in HCM patients.

Assessment of CAD by CT HCM group(n = 84) Control group (n = 168) p-value Agatston score 9 [0-225] 4 [0-82] 0.22 No. of pts with score* 0.07 0-399 31 (89%) 149 (91%) &gt;400 8 (11%) 15 (9%) Obstructive CAD 15 (18%) 32 (19%) 0.82 No. of pts with MB 42 (50%) 42 (25%) &lt;0.001 No. of vessels with MB &lt;0.001 1 34 (40%) 39 (23%) 2 8 (10%) 3 (2%) No. of pts with &gt;1 segment with MB 12 (14%) 4 (2%) &lt;0.001 Abbreviations CAD = Coronary artery disease, MB = Myocardial bridging, pts = patients *Only measured in 73/84 HCM patients and in 164/168 control patients

P278 Pharmacokinetics, pharmacodynamics and efficacy of OPC-61815, prodrug of tolvaptan for intravenous administration, in patients with congestive heart failure

Funding Acknowledgements

Otsuka Pharmaceutical Co. Ltd.

On Behalf

OPC-61815 phase II investigators

Background/Introduction: Tolvaptan, a vasopression V2-receptor antagonist, is effective for congestion in patients with congestive heart failure (CHF), and hyponatremia in patients with CHF and SIADH. But, this drug is not readily soluble in water and not suited for development as an injection. OPC-61815, a prodrug of tolvaptan having improved water solubility, is suitable for intravenous administration.

Purpose

The phase-II clinical study (ClinicalTrials.gov Identifier: NCT03254108) was conducted to investigate the dose for intravenous administration of OPC-61815 achieving tolvaptan exposure equivalent to that for oral administration of tolvaptan 15-mg tablet in CHF patients.

Methods

This study was a multicenter, a double-blind, randomized, active-controlled, parallel-group comparison clinical pharmacology trial. Sixty patients aged between 20 and 85 years with CHF with volume overload despite the use of conventional diuretics were randomly assigned to four treatment cohorts to receive OPC-61815 at doses of 2, 4, 8, 16 mg (i.v.) or tolvaptan at 15 mg (p.o.). Both drugs were administered once a day for 5 days. The primary endpoint was to assess the dose of OPC-61815 equivalent to tolvaptan at 15 mg using Cmax and AUC24h values after the first administration. Pharmacodynamics (urine volume, urine osmolality, serum electrolyte concentration, biomarkers), efficacy (body weight change, congestive symptoms) and safety were also evaluated.

Results

The mean Cmax and AUC of the metabolite tolvaptan increased dose-dependently following single intravenous administration of OPC-61815 at 2, 4, 8, and 16 mg. Tolvaptan exposure (Cmax and AUC24h) on Day 1 following single intravenous administration of OPC-61815 at 16 mg was the closest and similar to that following single administration of tolvaptan 15-mg tablet. OPC-61815 increased urine volume from baseline, leading to decrease in body weight and improvement of lower limb edema. The incidence of treatment-emergent adverse events was 54.2% (26/48 subjects) in the OPC-61815 2 to 16-mg, and 83.3% (10/12 subjects) in the tolvaptan 15-mg groups. No clinically relevant changes from baseline were found in laboratory parameters, vital signs, or ECG findings.

Conclusions

Tolvaptan exposure on Day 1 following single intravenous administration of OPC-61815 at 16 mg was the most similar to that following single administration of tolvaptan 15-mg tablet. There was no marked difference in tolerability between OPC-61815 at 16 mg and tolvaptan 15-mg tablet, and no clinically significant problems were observed.

Feature-Tracking MRI Fractal Analysis of Right Ventricular Remodeling in Adults with Congenitally Corrected Transposition of the Great Arteries

Purpose

To assess a recently available technique for quantification of right ventricular (RV) trabeculae that is based on fractal analysis performed by using cardiac MRI feature tracking, in patients with congenitally corrected transposition of the great arteries (cc-TGA).

Materials and Methods

A total of 19 patients (eight men, 11 women; mean age, 35 years ± 10 [standard deviation]) with consecutive cc-TGA who underwent cardiac MRI were enrolled in the study. For analysis, patients were divided into two groups: six patients (four men, two women; mean age, 34 years ± 14) with an end-systolic RV volume index higher than 72 mL/m² (indicative of adverse RV remodeling) and 13 patients (four men, nine women; mean age, 36 years ± 9) in whom this index was lower than or equal to 72 mL/m² (indicative of adapted RV). The following outcomes were quantified in the midsection of the RV: fractional fractal dimension (FD) and diastolic FD, circumferential strain, and radial strain. Receiver operating characteristic (ROC) analysis was performed to determine the cutoff FD values for the detection of adverse RV remodeling. Correlations among fractional FD, diastolic FD, circumferential strain, and radial strain were calculated by using Pearson correlation coefficient (r) analysis.

Results

The following ROC values were identified for fractional and diastolic FD: cutoff, 0.09 and 1.39, respectively; area under the ROC curve, 0.95 and 0.68, respectively; sensitivity, 1.00 and 0.33, respectively; and specificity, 0.92 and 1.00, respectively. Fractional FD correlated with circumferential strain and radial strain (r = -0.70 and 0.69, respectively; P < .01), as did diastolic FD (r = 0.37 and -0.38, respectively; P < .05).

Conclusion

The fractional FD derived from cardiac MRI feature-tracking analysis correlates with adverse RV remodeling, including a changed strain pattern and trabeculae, in patients with cc-TGA.© RSNA, 2019.

P6170Incremental value of on-site computed tomography-derived fractional flow reserve for the diagnosis and management strategy of obstructive coronary artery disease in the randomized CRESCENT trials

Background

Coronary computed tomography angiography (CCTA) accurately rules out coronary artery disease (CAD), but has a limited ability to predict hemodynamically significant CAD. Implementing on-site computed tomography-derived fractional flow reserve (CT-FFR) could improve the clinical value and efficiency of cardiac CT in the diagnostic work-up of patients with stable angina.

Purpose

To determine the impact of on-site CT-FFR on diagnostic effectiveness, management strategy and downstream invasive coronary angiography (ICA) in patients with suspected CAD.

Methods

196 patients (59.1±9.6 years, 47% women) with suspected CAD underwent a CCTA in the CRESCENT I and II trials. On-site CT-FFR analysis was performed in all patients with at least one ≥50% stenosis on CCTA (N=53). We assessed the effect of adding CT-FFR analysis to CCTA in terms of 1) diagnostic effectiveness, i.e. the number of additional tests required to determine the final diagnosis; 2) reclassification of the initial management strategy; 3) ICA efficiency, i.e. ICA rate without ≥50% CAD.

Results

CT-FFR was calculated in 42/53 (79%) of the eligible patients as it could not be calculated in patients with suspected coronary total occlusion (N=7), severe coronary calcification (N=2), severe CT artefacts (N=1) or missing CT images (N=1). CT-FFR ≤0.80 was present in 27/196 (14%) patients, including 8/196 (4%) patients with high-risk ischemia (CT-FFR ≤0.80 in all three vessels, left main or proximal left anterior descending coronary artery). The final diagnosis was achieved with CT-FFR in an additional 30/196 (15%) patients compared to CT alone (p<0.0001), and rendered 42/56 (75%) of additional tests unnecessary (p<0.0001). The initial management strategy was reclassified in 30/196 patients (15%, p<0.0001); 24/196 (12%) patients were reclassified to optimal medical therapy and 6/196 (3%) patients were reclassified directly to ICA including 4/8 (50%) patients with high-risk CAD on ICA. CT-FFR would result in 6/32 (19%, p=0.012) ICA cancellations in which none of the patients had high-risk CAD. The rate of ICA without ≥50% stenosis would decrease from 22% (7/32) to 11% (3/27) (p=0.012).

Conclusion

Implementation of CT-FFR has the potential for improved diagnostic effectiveness. Functional reclassification of CAD provides more efficient ICA referral in patients with suspected CAD compared to CTA alone.

Acknowledgement/Funding

Dutch Heart Foundation [NHS 2014T061 and NHS 2013T071]

Localized malignant pleural mesothelioma mimicking an anterior mediastinal tumor

Localized malignant pleural mesothelioma (LMPM) is an extremely rare tumor. We report the case of a 40-year-old Japanese male with an LMPM mimicking an anterior mediastinal tumor due to invasion to the anterior mediastinum, and we discuss mainly the differentiation of LMPM from an anterior mediastinal tumor. The present tumor had a long shape along the pleura, and LMPM could be one of the differential diagnoses.

Feasible scan timing for 320-row coronary CT angiography generated by the time to peak in the ascending aorta

PURPOSE

A 320-row CT scanner can briefly scan the entire heart. Therefore, the feasible scan timing is required. The aim of this study was to propose a refined method for feasible scan timing for coronary CT angiography (CCTA) using a time-density curve of the ascending aorta (AAo).

METHODS

One-hundred and twenty-nine patients were prospectively enrolled. All patients were performed test-bolus method. For the initial 65 patients, the scan timing was determined as a 3.0 s delay at the peak time in the AAo, which was defined as the conventional protocol (COV-P). For the next 64 patients, a scan timing of 1.0, 3.0, or 5.0 s delay was determined according to the interval from the contrast media arrival to peak time in the AAo, which was defined as the arrival to peak protocol (AP-P). The optimal scan timing was identified by the measurement of CT number in the left atrium, left ventricle, AAo, and descending aorta. The coronary enhancement and heterogeneity were compared between the two protocols.

RESULTS

The optimal scan timing was significantly higher in the AP-P than in the COV-P (85.9% vs. 61.5%, p = 0.0017). The CT number in the left circumflex artery (LCX) was significantly higher in the AP-P than the COV-P (344.5 Hounsfield units vs. 316.3 Hounsfield units, p = 0.0484). The heterogeneous index of the LCX was significantly greater for the COV-P than the AP-P (-36.8 vs. -25.8, p = 0.0028).

CONCLUSIONS

The AP-P can be used to determine the optimal scan timing for CCTA and contributes to stable coronary enhancement.

Tensile-Strain-Dependent Spin States in Epitaxial LaCoO_{3} Thin Films

The spin states of Co^{3+} ions in perovskite-type LaCoO_{3}, governed by the complex interplay between the electron-lattice interactions and the strong electron correlations, still remain controversial due to the lack of experimental techniques which can directly detect them. In this Letter, we revealed the tensile-strain dependence of spin states, i.e., the ratio of the high- and low-spin states, in epitaxial thin films and a bulk crystal of LaCoO_{3} via resonant inelastic soft x-ray scattering. A tensile strain as small as 1.0% was found to realize different spin states from that in the bulk.