Laterality of CT-measured hepatic extracellular volume fraction in patients with chronic thromboembolic pulmonary hypertension.

PURPOSE: This study examines the hepatic extracellular volume fraction (ECV) disparity between the left and right lobes (ECV_left and ECV_right) in patients with chronic thromboembolic pulmonary hypertension (CTEPH), its association with right heart catheterization (RHC) metrics, and with intolerance to increased pulmonary hypertension (PH)-targeted medication dosages. METHODS: We retrospectively analyzed 72 CTEPH-diagnosed patients who underwent equilibrium-phase abdominal dual-energy CT (DECT) and RHC. Hepatic ECVs, derived from DECT's iodine maps using circular regions of interest in the liver and aorta, were correlated with RHC parameters via Spearman's rank correlation and lobe differences through the Wilcoxon signed-rank test. Logistic regression assessed cases with ECV_left exceeding ECV_right by > 0.05, while receiver operating characteristic curve analysis gauged ECVs' predictive power for medication intolerance. RESULTS: Of the 72 patients (57 females; median age 69), ECV_total (0.24, IQR 0.20-0.27) moderately correlated with RHC parameters (rs = 0.28, -0.24, 0.3 for mean pulmonary arterial pressure, cardiac index [CI], and pulmonary vascular resistance index, respectively). ECV_left significantly surpassed ECV_right (0.25 vs. 0.22, p < 0.001), with a greater ECV_left by > 0.05 indicating notably lower CI (p < 0.001). In 27 patients on PH medication, ECV_left effectively predicted medication intolerance (AUC = 0.84). CONCLUSION: In CTEPH patients, hepatic ECV correlated with RHC metrics, where elevated left lobe ECV suggested reduced CI and potential medication intolerance.

Covering the intercostal artery branching of the Adamkiewicz artery during endovascular aortic repair increases the risk of spinal cord ischemia.

Objectives: This study aimed to determine the relationship between covering the intercostal artery branching of the Adamkiewicz artery (ICA-AKA) and spinal cord ischemia (SCI) during thoracic endovascular aortic repair (TEVAR). Methods: Patients who underwent TEVAR from 2008 to 2022 were enrolled. Stent grafts covered the ICA-AKA in 108 patients (covered AKA group) and stent grafts didn't cover the ICA-AKA in 114 patients (uncovered AKA group). The characteristics of 58 patients from each group were matched based on propensity scores. Results: No significant differences in SCI rates were detected between the covered AKA (10%; 11/108) and uncovered AKA (3.5%; 4/114) groups (P = .061). Shaggy aorta (odds ratio [OR], 5.16; 95% confidence interval [CI], 1.74-15.3, P = .003), iliac artery access (OR, 6.81; 95% CI, 2.22-20.9, P = .001), and procedural time (OR, 1.01; 95% CI, 1.00-1.02, P = .003) were risk factors for SCI in the entire cohort. Although covering the ICA-AKA (OR, 2.60; 95% CI, 0.86-7.88, P = .058) was not a significant risk factor, shaggy aorta (OR, 8.15; 95% CI, 2.07-32.1, P = .003), iliac artery access (OR, 9.09; 95% CI, 2.22-37.2, P = .002), and procedural time (OR, 1.01; 95% CI, 1.01-1.02, P = .008) were risk factors for SCI in the covered AKA group. No significant risk factors were detected in the uncovered AKA group. Conclusions: Covering the ICA-AKA was not an independent risk for SCI in TEVAR. However, covering the ICA-AKA was indirectly associated with the risk of SCI in patients with shaggy aorta, iliac access, and procedural time.

Interference of cardiac implantable electronic devices and computed tomography imaging in the current era with a phantom model.

Introduction: Cardiac implantable electronic devices are used in patients with cardiac rhythm disorders. Computed tomography irradiation is not prohibited for patients with cardiac implantable electronic devices, despite adverse events being reported. Hence, appropriate preparation and knowledge are required before computed tomography irradiation can be carried out in these patients. Since there is limited knowledge or literature about the influence of computed tomography irradiation in cases with recent cardiac implantable electronic devices, we aimed to evaluate the adverse events and elucidate the necessary and sufficient safety measures associated with this therapy. Methods and Results: We placed cardiac implantable electronic devices on an anthropomorphic phantom model and observed their electrical activity in electrograms, while various protocols of computed tomography irradiation were implemented and adverse events evaluated. Oversensing with pauses of up to 3.2 s was observed in standard computed tomography protocols, but ventricular tachyarrhythmia or other clinically significant events could not be confirmed. Oversensing with pauses of up to 8.0 s was observed and ventricular tachyarrhythmia was detected in the maximum-dose protocols. However, treatments such as antitachycardia pacing or shock therapy for ventricular tachyarrhythmia were not observed because of their absence. Conclusion: Computed tomography irradiation for patients using cardiac implantable electronic devices is highly unlikely to cause clinically significant adverse events with the device settings and computed tomography protocols currently being used. Changing or monitoring the device settings routinely before computed tomography irradiation is not necessarily required for most patients.

Characterization of plaque phenotypes exhibiting an elevated pericoronary adipose tissue attenuation: insights from the REASSURE-NIRS registry.

Inflammation has been considered to promote atheroma instability. Coronary computed tomography angiography (CCTA) visualizes pericoronary adipose tissue (PCAT) attenuation, which reflects coronary artery inflammation. While PCAT attenuation has been reported to predict future coronary events, plaque phenotypes exhibiting high PCAT attenuation remains to be fully elucidated. The current study aims to characterize coronary atheroma with a greater vascular inflammation. We retrospectively analyzed culprit lesions in 69 CAD patients receiving PCI from the REASSURE-NIRS registry (NCT04864171). Culprit lesions were evaluated by both CCTA and near-infrared spectroscopy/intravascular ultrasound (NIRS/IVUS) imaging prior to PCI. PCAT attenuation at proximal RCA (PCATRCA) and NIRS/IVUS-derived plaque measures were compared in patients with PCATRCA attenuation ≥ and < -78.3 HU (median). Lesions with PCATRCA attenuation ≥ -78.3 HU exhibited a greater frequency of maxLCBI4mm ≥ 400 (66% vs. 26%, p < 0.01), plaque burden ≥ 70% (94% vs. 74%, p = 0.02) and spotty calcification (49% vs. 6%, p < 0.01). Whereas positive remodeling (63% vs. 41%, p = 0.07) did not differ between two groups. On multivariable analysis, maxLCBI4mm ≥ 400 (OR = 4.07; 95%CI 1.12-14.74, p = 0.03), plaque burden ≥ 70% (OR = 7.87; 95%CI 1.01-61.26, p = 0.04), and spotty calcification (OR = 14.33; 95%CI 2.37-86.73, p < 0.01) independently predicted high PCATRCA attenuation. Of note, while the presence of only one plaque feature did not necessarily elevate PCATRCA attenuation (p = 0.22), lesions harboring two or more features were significantly associated with higher PCATRCA attenuation. More vulnerable plaque phenotypes were observed in patients with high PCATRCA attenuation. Our findings suggest PCATRCA attenuation as the presence of profound disease substrate, which potentially benefits from anti-inflammatory agents.

Deep Learning-based Post Hoc CT Denoising for the Coronary Perivascular Fat Attenuation Index.

RATIONALE AND OBJECTIVES: Coronary inflammation related to high-risk hemorrhagic plaques can be captured by the perivascular fat attenuation index (FAI) using coronary computed tomography angiography (CCTA). Since the FAI is susceptible to image noise, we believe deep learning (DL)-based post hoc noise reduction can improve diagnostic capability. We aimed to assess the diagnostic performance of the FAI in DL-based denoised high-fidelity CCTA images compared with coronary plaque magnetic resonance imaging (MRI) delivered high-intensity hemorrhagic plaques (HIPs). MATERIALS AND METHODS: We retrospectively reviewed 43 patients who underwent CCTA and coronary plaque MRI. We generated high-fidelity CCTA images by denoising the standard CCTA images using a residual dense network that supervised the denoising task by averaging three cardiac phases with nonrigid registration. We measured the FAIs as the mean CT value of all voxels (range of -190 to -30 HU) located within a radial distance from the outer proximal right coronary artery wall. The diagnostic reference standard was defined as HIPs (high-risk hemorrhagic plaques) using MRI. The diagnostic performance of the FAI in the original and denoised images was assessed using receiver operating characteristic curves. RESULTS: Of 43 patients, 13 had HIPs. The denoised CCTA improved the area under the curve (0.89 [95% confidence interval (CI) 0.78-0.99]) of the FAI compared with that in the original image (0.77 [95% CI, 0.62-0.91], p = 0.008). The optimal cutoff value for predicting HIPs in denoised CCTA was -69 HU with 0.85 (11/13) sensitivity, 0.79 (25/30) specificity, and 0.80 (36/43) accuracy. CONCLUSION: DL-based denoised high-fidelity CCTA improved the AUC and specificity of the FAI for predicting HIPs.

Optimization of null point in Look-Locker images for myocardial late gadolinium enhancement imaging using deep learning and a smartphone.

OBJECTIVES: To determine the optimal inversion time (TI) from Look-Locker scout images using a convolutional neural network (CNN) and to investigate the feasibility of correcting TI using a smartphone. METHODS: In this retrospective study, TI-scout images were extracted using a Look-Locker approach from 1113 consecutive cardiac MR examinations performed between 2017 and 2020 with myocardial late gadolinium enhancement. Reference TI null points were independently determined visually by an experienced radiologist and an experienced cardiologist, and quantitatively measured. A CNN was developed to evaluate deviation of TI from the null point and then implemented in PC and smartphone applications. Images on 4 K or 3-megapixel monitors were captured by a smartphone, and CNN performance on each monitor was determined. Optimal, undercorrection, and overcorrection rates using deep learning on the PC and smartphone were calculated. For patient analysis, TI category differences in pre- and post-correction were evaluated using the TI null point used in late gadolinium enhancement imaging. RESULTS: For PC, 96.4% (772/749) of images were classified as optimal, with under- and overcorrection rates of 1.2% (9/749) and 2.4% (18/749), respectively. For 4 K images, 93.5% (700/749) of images were classified as optimal, with under- and overcorrection rates of 3.9% (29/749) and 2.7% (20/749), respectively. For 3-megapixel images, 89.6% (671/749) of images were classified as optimal, with under- and overcorrection rates of 3.3% (25/749) and 7.0% (53/749), respectively. On patient-based evaluations, subjects classified as within optimal range increased from 72.0% (77/107) to 91.6% (98/107) using the CNN. CONCLUSIONS: Optimizing TI on Look-Locker images was feasible using deep learning and a smartphone. KEY POINTS: • A deep learning model corrected TI-scout images to within optimal null point for LGE imaging. • By capturing the TI-scout image on the monitor with a smartphone, the deviation of the TI from the null point can be immediately determined. • Using this model, TI null points can be set to the same degree as that by an experienced radiological technologist.

Thoracic endovascular aortic repair with collateral vessels from the femoral artery to Adamkiewicz's artery.

Identification of the Adamkiewicz's artery (AKA) prior to the operation is one of the spinal cord ischaemia preventive measures. A 75-year-old man presented with the rapid expansion of thoracic aortic aneurysm. Collateral vessels from the right common femoral artery to the AKA were observed on preoperative computed tomography angiography. The stent graft was successfully deployed through the contralateral side via a pararectal laparotomy to avoid collateral vessel injury supplying the AKA. This case highlights the significance of preoperative identification of collateral vessels to the AKA.

Structural characteristics of patients with superior vena cava foci initiating atrial fibrillation: Analysis with electrocardiogram-triggered computed tomography.

INTRODUCTION: The superior vena cava (SVC) is the most common source of non-pulmonary vein foci in atrial fibrillation (AF); therefore, predicting the existence of non-pulmonary vein foci before the catheter ablation procedure helps construct a proper ablation strategy in preparation for SVC isolation. This study aimed to clarify the structural characteristics of patients with SVC foci initiating AF. METHODS: We enrolled 331 consecutive patients with AF who underwent cardiac computed tomography imaging before radiofrequency catheter ablation treatment, and they were divided into SVC (+) and (-) groups based on the presence or absence of SVC foci initiating AF. RESULTS: The SVC (+) group (n = 27) exhibited SVC crescent signs-defined as a curve-shaped SVC with two narrow pointed ends-more frequently (37% vs. 9%, p < .001), and larger right atrial volume (95.6 ± 20.8 vs. 80.5 ± 26.1 mL, p = .004) than the SVC (-) group (n = 304). Multivariate logistic regression analysis revealed that the SVC crescent sign (odds ratio, 8.88; 95% confidence interval [CI], 3.21-24.60) and right atrial volume (odds ratio, 1.03; 95% CI, 1.01-1.04) were independent predictors of SVC foci. CONCLUSION: Patients with SVC foci exhibited more frequent SVC crescent signs and larger right atrial volumes, and these characteristics may help clinicians choose the appropriate ablation technology.

Generative adversarial network-based post-processed image super-resolution technology for accelerating brain MRI: comparison with compressed sensing.

BACKGROUND: It is unclear whether deep-learning-based super-resolution technology (SR) or compressed sensing technology (CS) can accelerate magnetic resonance imaging (MRI) . PURPOSE: To compare SR accelerated images with CS images regarding the image similarity to reference 2D- and 3D gradient-echo sequence (GRE) brain MRI. MATERIAL AND METHODS: We prospectively acquired 1.3× and 2.0× faster 2D and 3D GRE images of 20 volunteers from the reference time by reducing the matrix size or increasing the CS factor. For SR, we trained the generative adversarial network (GAN), upscaling the low-resolution images to the reference images with twofold cross-validation. We compared the structural similarity (SSIM) index of accelerated images to the reference image. The rate of incorrect answers of a radiologist discriminating faster and reference image was used as a subjective image similarity (ISM) index. RESULTS: The SR demonstrated significantly higher SSIM than the CS (SSIM=0.9993-0.999 vs. 0.9947-0.9986; P < 0.001). In 2D GRE, it was challenging to discriminate the SR image from the reference image, compared to the CS (ISM index 40% vs. 17.5% in 1.3×; P = 0.039 and 17.5% vs. 2.5% in 2.0×; P = 0.034). In 3D GRE, the CS revealed a significantly higher ISM index than the SR (22.5% vs. 2.5%; P = 0.011) in 2.0 × faster images. However, the ISM index was identical for the 2.0× CS and 1.3× SR (22.5% vs. 27.5%; P = 0.62) with comparable time costs. CONCLUSION: The GAN-based SR outperformed CS in image similarity with 2D GRE for MRI acceleration. In addition, CS was more advantageous in 3D GRE than SR.

Deep learning-based noise reduction for coronary CT angiography: using four-dimensional noise-reduction images as the ground truth.

BACKGROUND: To assess low-contrast areas such as plaque and coronary artery stenosis, coronary computed tomography angiography (CCTA) needs to provide images with lower noise without increasing radiation doses. PURPOSE: To develop a deep learning-based noise-reduction method for CCTA using four-dimensional noise reduction (4DNR) as the ground truth for supervised learning. MATERIAL AND METHODS: \We retrospectively collected 100 retrospective ECG-gated CCTAs. We created 4DNR images using non-rigid registration and weighted averaging three timeline CCTA volumetric data with intervals of 50 ms in the mid-diastolic phase. Our method set the original reconstructed image as the input and the 4DNR as the target image and obtained the noise-reduced image via residual learning. We evaluated the objective image quality of the original and deep learning-based noise-reduction (DLNR) images based on the image noise of the aorta and the contrast-to-noise ratio (CNR) of the coronary arteries. Further, a board-certified radiologist evaluated the blurring of several heart structures using a 5-point Likert scale subjectively and assigned a coronary artery disease reporting and data system (CAD-RADS) category independently. RESULTS: DLNR CCTAs showed 64.5% lower image noise (P < 0.001) and achieved a 2.9 times higher CNR of coronary arteries than that in original images, without significant blurring in subjective comparison (P > 0.1). The intra-observer agreement of CAD-RADS in the DLNR image was excellent (0.87, 95% confidence interval = 0.77-0.99) with original CCTAs. CONCLUSION: Our DLNR method supervised by 4DNR significantly reduced the image noise of CCTAs without affecting the assessment of coronary stenosis.

Patient positioning during pediatric cardiothoracic computed tomography using a high-resilience pad system and pre-scan measurement of chest thickness.

Patient positioning at the isocenter of the CT gantry is important for optimizing image quality and radiation dose, but accurate positioning is challenging in pediatric patients. We evaluated whether the high-resilience pad and pre-scan measurement of chest thickness allow accurate positioning in pediatric patients with congenital heart disease. Sixty-seven patients aged 7 years or younger who underwent cardiothoracic CT were enrolled. The ideal table height, defined as the position at which the scanner's and patient's isocenters coincided, was determined by radiographers either manually (manual group) or based on the pad's and chest's thickness (calculated group). The distance between the two isocenters and image quality were evaluated. The calculated group demonstrated smaller isocenter distance and standard deviation (distance: 0.2 ± 5.8 mm vs. - 8.3 ± 11.6 mm, p < 0.01; absolute value: 4.1 [1.9-8.0] mm vs. 12.3 [5.1-16.3] mm, p < 0.01), and higher signal-to-noise ratio (SNR) and dose-normalized SNR (SNRD) in the descending aorta than the manual group (SNR: 39.8 [31.0-53.7] vs. 31.9 [28.9-36.6], p = 0.048, SNRD: 39.8 [31.0-53.7] vs. 31.9 [28.9-36.6], p = 0.04). The system allowed for more accurate positioning in pediatric cardiothoracic CT, yielding higher image quality.

Balloon Pulmonary Angioplasty in the Management of Chronic Thromboembolic Pulmonary Hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH), which is classified as group 4 pulmonary hypertension (PH) in the 2015 European Society of Cardiology/European Respiratory Society guidelines for the diagnosis and treatment of PH, is regarded as a complication of pulmonary embolism and is caused by the transformation of incompletely resolved thrombi into fibrous tissue that occludes the pulmonary arteries. The current established reference standard curative therapy for CTEPH is pulmonary endarterectomy (PEA), which provides good long-term outcomes with a low mortality rate. For patients with inoperable disease with inaccessible lesions and risk factors for surgery or patients who are diagnosed with residual or recurrent PH after PEA, medical therapy with riociguat is recommended. Balloon pulmonary angioplasty (BPA) is an emerging alternative treatment option for patients with inoperable disease or those with residual or recurrent PH after PEA. BPA has been reported to improve hemodynamics, cardiac function, exercise capacity, and symptoms, as well as PEA. A detailed assessment of thromboembolic lesions in pulmonary arteries by using multiple imaging techniques and treatment strategies with multiple staged procedures based on the patient's condition is important for safe and effective BPA. However, this new technique may still induce life-threatening complications, such as reperfusion pulmonary edema, wire perforation, vessel dissection, and vessel rupture. Meticulous attention to technique is mandatory to minimize serious complications owing to the nature of the anatomic territory involved. The authors summarize the current roles, goals, and complications of BPA in patients with CTEPH and demonstrate ways to formulate an effective and safe treatment strategy. The future perspective of BPA is also discussed. Online supplemental material is available for this article. ©RSNA, 2022.

Assessment of the upper limb muscles in patients with Fukuyama muscular dystrophy: Noninvasive assessment using visual ultrasound muscle analysis and shear wave elastography.

Fukuyama-type congenital muscular dystrophy (FCMD) is severe, childhood-onset muscular dystrophy. Recently, our group has discovered a potential treatment using antisense oligonucleotides. Therefore, an effective, reliable, and objective method of assessing muscle is needed. Ultrasound is a minimally invasive tool that can be applied without radiation exposure or pain. Evaluating tissue stiffness by shear wave elastography (SWE) has especially recently attracted attention. Here, we aimed to evaluate SWE value of the upper limb muscles: biceps brachii, triceps brachii, brachioradialis, abductor pollicis brevis, and abductor finger muscle in patients with FCMD. Upper extremity function was evaluated by visual muscle ultrasound analysis (VMUA) and SWE in 13 patients with FCMD and 20 healthy controls. The motor function evaluation tool was used to evaluate motor function, and the correlation with the dynamics of the SWE was determined. VMUA scaled using the Heckmatt scale was higher in patients with FCMD. SWE was also significantly higher and stiffer in the biceps brachii and brachioradialis in patients with FCMD. Furthermore, the severity of FCMD symptoms was correlated with muscle stiffness. We conclude that VMUA and SWE can be useful tools for monitoring muscle atrophy and upper limb function in patients with FCMD.

Deep Learning-based Post Hoc CT Denoising for Myocardial Delayed Enhancement.

Background To improve myocardial delayed enhancement (MDE) CT, a deep learning (DL)-based post hoc denoising method supervised with averaged MDE CT data was developed. Purpose To assess the image quality of denoised MDE CT images and evaluate their diagnostic performance by using late gadolinium enhancement (LGE) MRI as a reference. Materials and methods MDE CT data obtained by averaging three acquisitions with a single breath hold 5 minutes after the contrast material injection in patients from July 2020 to October 2021 were retrospectively reviewed. Preaveraged images obtained in 100 patients as inputs and averaged images as ground truths were used to supervise a residual dense network (RDN). The original single-shot image, standard averaged image, RDN-denoised original (DLoriginal) image, and RDN-denoised averaged (DLave) image of holdout cases were compared. In 40 patients, the CT value and image noise in the left ventricular cavity and myocardium were assessed. The segmental presence of MDE in the remaining 40 patients who underwent reference LGE MRI was evaluated. The sensitivity, specificity, and accuracy of each type of CT image and the improvement in accuracy achieved with the RDN were assessed using odds ratios (ORs) estimated with the generalized estimation equation. Results Overall, 180 patients (median age, 66 years [IQR, 53-74 years]; 107 men) were included. The RDN reduced image noise to 28% of the original level while maintaining equivalence in the CT values (P < .001 for all). The sensitivity, specificity, and accuracy of the original images were 77.9%, 84.4%, and 82.3%, of the averaged images were 89.7%, 87.9%, and 88.5%, of the DLoriginal images were 93.1%, 87.5%, and 89.3%, and of the DLave images were 95.1%, 93.1%, and 93.8%, respectively. DLoriginal images showed improved accuracy compared with the original images (OR, 1.8 [95% CI: 1.2, 2.9]; P = .011) and DLave images showed improved accuracy compared with the averaged images (OR, 2.0 [95% CI: 1.2, 3.5]; P = .009). Conclusion The proposed denoising network supervised with averaged CT images reduced image noise and improved the diagnostic performance for myocardial delayed enhancement CT. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Vannier and Wang in this issue.

Crizotinib for ROS1-rearranged lung cancer and pulmonary tumor thrombotic microangiopathy under venoarterial extracorporeal membrane oxygenation.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rapidly progressive subtype of pulmonary hypertension (PH) associated with impaired right ventricular adaptation and very poor prognosis in cancer, and its rapid progression makes antemortem diagnosis and treatment extremely difficult. We describe the case of a 35-year-old woman who developed severe PH with subsequent circulatory collapse. The patient was clinically diagnosed with PTTM induced by lung adenocarcinoma harboring the c-ros oncogene 1 (ROS1) rearrangement within 1-2 weeks, while hemodynamics were stabilized by rescue venoarterial extracorporeal membrane oxygenation support. Crizotinib, an oral tyrosine kinase inhibitor targeting anaplastic lymphoma kinase, MET, and ROS1 kinase domains dramatically resolved PH, resulting in more than 3 years of survival. Targeted gene-tailored therapy with mechanical support can improve survival in PTTM.

Stereogram of the Living Heart, Lung, and Adjacent Structures.

Innovations in invasive cardiovascular diagnostics and therapeutics, not only limited to transcatheter approaches but also involving surgical approaches, are based on a precise appreciation of the three-dimensional living heart anatomy. Rapid advancements in three-dimensional cardiovascular imaging technologies in the 21st century have supported such innovations through the periprocedural assessment of the clinical anatomy of the living heart. However, even if high-resolution volume-rendered images are reconstructed, they cannot provide appropriate depth perception when displayed and shared on a two-dimensional display, which is widely used in clinical settings. Currently, images reconstructed from clinical datasets can visualize fine details of the cardiovascular anatomy. Therefore, this is an optimal time for cardiologists and cardiac surgeons to revisit the classic technology, stereopsis, and obtain bonus information from carefully reconstructed clinical images. Using anaglyphs or cross/uncross-fusion of paired images, striking depth perception can be readily obtained without the need for expensive equipment. This conventional technique, when applied to high-resolution volume-rendered images, may help in obtaining appropriate diagnostics, choosing optimal therapeutics, securing procedural success, and preventing complications. Furthermore, it can be used for anatomical education. In this review, we demonstrate multiple stereoscopic images reconstructed from cardiac computed tomographic datasets and discuss their clinical and educational implications.

Left coronary ostial stenosis developing 15 months after transcatheter aortic valve replacement with balloon-expandable valve.

We present the case of an 82-year-old man whose left coronary ostium became obstructed 15 months after transcatheter aortic valve replacement (TAVR) with a balloon-expandable valve. The patient underwent TAVR for symptomatic severe aortic stenosis with no complications. Fifteen months after the initial TAVR, the patient complained of chest pain while exercising, and the exercise stress myocardial perfusion scintigraphy demonstrated the development of regional myocardial ischemia in the region of the left coronary artery. Coronary angiography implied severe stenosis in the ostium of the left coronary artery. Computed tomography angiography and intravascular ultrasonography indicated a soft tissue component along with stent struts, which was considered to cause delayed coronary obstruction. Our report emphasizes the importance of having a low threshold for clinically suspecting delayed coronary obstruction in patients who have undergone TAVR, even after several years of the procedure. .

Image Quality of Submillimeter High-Spatial-Resolution 2D Late Gadolinium-enhanced Images in Cardiac MRI: A Feasibility Study.

Purpose: To evaluate the image quality of high-spatial-resolution two-dimensional (2D) late gadolinium enhancement (LGE) cardiac MRI compared with conventional normal-resolution LGE MRI. Materials and Methods: This prospective study included participants suspected of having cardiomyopathy who underwent cardiac MRI between March 2021 and December 2021. Normal-resolution and high-resolution 2D LGE sequences (inversion recovery [IR] and phase-sensitive inversion recovery [PSIR]) were performed at 3 T. Resolution was compared between normal-resolution and high-resolution images obtained in a quality assurance phantom. In vivo image quality and resolution were evaluated qualitatively using a five-point scoring system. Receiver operating characteristic curve analysis was used for LGE detection performance. Border sharpness was assessed with profile curve measurement. The contrast-to-noise ratio (CNR) between hyperenhancement and remote myocardium and LGE detection performance were calculated using normal-resolution IR images as the reference. Results: In total, 120 participants were evaluated (mean age, 56 years ± 17 [SD]; 72 men). Features smaller than 1 mm were detectable only on high-resolution images of the phantom. In vivo, the image resolution score with high-resolution LGE was 4.14-4.24, which was higher than the normal-resolution LGE reference score of 2.99 (P < .05). Border sharpness was higher in high-resolution images (P < .001). Receiver operating characteristic curve analysis revealed no evidence of a difference in LGE detection between normal-resolution and high-resolution images. There was also no evidence of a change in CNR of LGE in IR and PSIR magnitude compared with reference images. Conclusion: Comparison of image quality in 2D high-resolution and normal-resolution LGE cardiac MRI demonstrated the highest resolution for high-resolution IR and high-resolution PSIR magnitude sequences.Keywords: Cartilage Imaging, MRI, Cardiac, Heart, Imaging Sequences, Comparative Studies Supplemental material is available for this article. © RSNA, 2022.

Mechanical Thrombectomy Up to 24 Hours in Large Vessel Occlusions and Infarct Velocity Assessment.

Background We retrospectively compared early- (<6 hours) versus late- (6-24 hours) presenting patients using perfusion-weighted imaging selection and evaluated clinical/radiographic outcomes. Methods and Results Large vessel occlusion patients treated with mechanical thrombectomy from August 2017 to July 2020 within 24 hours of onset were retrieved from a single-center database. Perfusion-weighted imaging was analyzed by automated software and final infarct volume was measured semi-automatically within 14 days. The primary end point was good outcome (modified Rankin Scale 0-2 at 90 days). Secondary end points were excellent outcome (modified Rankin Scale 0-1 at 90 days), symptomatic intracranial hemorrhage, and death. Clinical characteristics/radiological values including hypoperfusion volume and infarct growth velocity (baseline volume/onset-to-image time) were compared between the groups. Of 1294 patients, 118 patients were included. The median age was 74 years, baseline National Institutes of Health Stroke Scale score was 14, and core volume was 13 mL. The late-presenting group had more female patients (67% versus 31%, respectively; P=0.001). No statistically significant differences were seen in good outcome (42% versus 53%, respectively; P=0.30), excellent outcome (26% versus 32%, respectively; P=0.51), symptomatic intracranial hemorrhage (6.5% versus 4.6%, respectively; P=0.74), and death (3.2% versus 5.7%, respectively; P=0.58) between the groups. The late-presenting group had more atherothrombotic cerebral infarction (19% versus 6%, respectively; P=0.03), smaller hypoperfusion volume (median: 77 versus 133 mL, respectively; P=0.04), and slower infarct growth velocity (median: 0.6 versus 5.1 mL/h, respectively; P=0.03). Conclusions Patients with early- and late-time windows treated with mechanical thrombectomy by automated perfusion-weighted imaging selection have similar outcomes, comparable with those in randomized trials, but different in infarct growth velocities. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02251665.