Pulmonary hypertension (PH) is broadly defined as a mean pulmonary arterial pressure (mPAP) exceeding 20 mm Hg at rest. Pulmonary arterial hypertension (PAH) is a specific subset of PH characterized by a normal pulmonary arterial wedge pressure (PAWP), combined with elevated mPAP and increased pulmonary vascular resistance (PVR), without other causes of pre-capillary hypertension such as lung diseases or chronic thromboembolic pulmonary hypertension. The majority of PAH cases are idiopathic; other common etiologies include connective tissue disease-associated PAH, congenital heart disease, and portopulmonary hypertension. To a lesser extent, genetic and familial forms of PAH can also occur. The pathophysiology of PAH involves the following four primary pathways: nitric oxide, endothelin-1, prostacyclin, and activin/bone morphogenetic protein (BMP). Dysregulation of these pathways leads to a progressive vasculopathy marked by vasoconstriction, vascular proliferation, elevated right heart afterload, and ultimately right-sided heart failure. Diagnosing PAH is challenging and often occurs at advanced stages. The gold standard for diagnosis remains invasive right heart catheterization. Along with invasive hemodynamic measurements, several noninvasive imaging modalities such as echocardiography and ventilation-perfusion scanning are key adjunct techniques. Also, recent advancements in cardiac magnetic resonance (CMR) have opened a new era for PAH management. Additionally, CMR and echocardiography not only enable diagnosis but also aid in evaluating disease severity and monitoring treatment responses. Current PAH treatments focus on targeting molecular pathways, reducing inflammation, and inhibiting right-sided heart failure. Integrating imaging with basic science techniques is crucial for enhanced patient diagnosis, and precision medicine is emerging as a key strategy in PAH management. Additionally, the incorporation of artificial intelligence into both molecular and imaging approaches holds significant potential. There is a growing need to integrate new imaging modalities with high resolution and reduced radiation exposure into clinical practice. In this review, we discuss the molecular pathways involved in PAH, the imaging modalities utilized for diagnosis and monitoring, and current targeted therapies. Advances in molecular understanding and imaging technologies, coupled with precision medicine, could hold promise in improving patient outcomes and revolutionizing the management of PAH patients.

Radiology: Cardiothoracic Imaging publishes research, technical developments, and reviews related to cardiac, vascular, and thoracic imaging. The current review article, led by the Radiology: Cardiothoracic Imaging trainee editorial board, highlights the most impactful articles published in the journal between November 2023 and October 2024. The review encompasses various aspects of cardiac, vascular, and thoracic imaging related to coronary artery disease, cardiac MRI, valvular imaging, congenital and inherited heart diseases, thoracic imaging, lung cancer, artificial intelligence, and health services research. Key highlights include the role of CT fractional flow reserve analysis to guide patient management, the role of MRI elastography in identifying age-related myocardial stiffness associated with increased risk of heart failure, review of MRI in patients with cardiovascular implantable electronic devices and fractured or abandoned leads, imaging of mitral annular disjunction, specificity of the Lung Imaging Reporting and Data System version 2022 for detecting malignant airway nodules, and a radiomics-based reinforcement learning model to analyze serial low-dose CT scans in lung cancer screening. Ongoing research and future directions include artificial intelligence tools for applications such as plaque quantification using coronary CT angiography and growing understanding of the interconnectedness of environmental sustainability and cardiovascular imaging. Keywords: CT, MRI, CT-Coronary Angiography, Cardiac, Pulmonary, Coronary Arteries, Heart, Lung, Mediastinum, Mitral Valve, Aortic Valve, Artificial Intelligence © RSNA, 2025.

Orthotopic heart transplant (OHT) is a well-established therapy for end-stage heart failure that leads to improved long-term survival rates, with careful allograft surveillance essential for optimizing clinical outcomes after OHT. Unfortunately, complications can arise after OHT that can compromise the success of the OHT. Cardiac MRI is continually evolving, with a range of advanced techniques that can be applied to evaluate allograft structure and function. Understanding the unique features of cardiac MRI in OHT recipients, identifying findings suggestive of acute or chronic complications, and recognizing the limitations of this imaging modality are essential for accurate interpretation of cardiac MRI findings and subsequent clinical reporting. The authors address the anticipated postsurgical anatomy and functionality of the OHT. Emphasis is placed on the advanced functional and tissue characterization features that can be seen in the stable OHT recipient, including global longitudinal strain, late gadolinium enhancement, native T1 and T2 mapping, and extracellular volume fraction. Subsequently, the evidence for detection of acute cardiac allograft rejection with cardiac MRI comprehensive tissue characterization techniques and the role of quantitative myocardial perfusion for cardiac allograft vasculopathy screening are discussed, with reference to their comparative standard of reference screening tests, including endomyocardial biopsy, invasive coronary angiography, and myocardial rest and stress perfusion PET/CT. Cardiac MRI has been included in contemporary OHT management guidelines and therefore can be considered a complementary tool for allograft evaluation. The authors demonstrate the complementary role cardiac MRI can play in cardiac allograft surveillance, with clinical examples. ©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Agarwal in this issue.

Noncirrhotic portal hypertension (NCPH) is an uncommon but important entity caused by impaired flow dynamics in the portal venous system in the absence of advanced fibrosis. The exact prevalence of this disease is unknown since many patients with NCPH are labeled as having cryptogenic cirrhosis. Numerous disease processes performed with different mechanisms can result in this entity. Based on the anatomic level of impairment of portal flow, NCPH is classified into prehepatic, intrahepatic, and posthepatic forms. The exact pathophysiology in many cases of intrahepatic NCPH is not well known, and there are overlapping terminologies used to describe histopathologic changes in the liver. The clinical and imaging findings are heterogeneous and are influenced by the mechanism and the underlying cause. In particular, patterns of portal hypertension and liver morphology are different among pre-, intra-, and posthepatic forms. All causes of NCPH can result in liver dysmorphism, but these changes are more drastic with intrahepatic and posthepatic forms (especially when associated with nodular regenerative hyperplasia) and can occasionally mimic cirrhosis. Prehepatic NCPH classically results in marked splenomegaly and large collateral formation with no ascites. On the other hand, ascites is the most common sign in posthepatic NCPH. Venographic pressure measurement and liver biopsy are required for definitive diagnosis. The authors review the current understanding of the mechanisms and causes of NCPH and discuss the approach to imaging findings, role of elastography, management, and complications. ©RSNA, 2025 Supplemental material is available for this article.

Quantitative stress perfusion (qPerf ) cardiac magnetic resonance (CMR) imaging is a noninvasive approach used to quantify myocardial blood flow (MBF). Compared with visual analysis, qPerf CMR has superior diagnostic accuracy in the detection of myocardial ischemia and assessment of ischemic burden. In the evaluation of epicardial coronary artery disease (CAD), qPerf CMR improves the distinction of single-vessel from multivessel disease, yielding a more accurate estimate of the ischemic burden, and in turn improving patient management. In patients with chest pain without epicardial CAD, the findings of lower stress MBF and myocardial perfusion reserve (MPR) allow the diagnosis of microvascular dysfunction (MVD). Given its accuracy, MBF quantification with stress CMR has been introduced into the most recent recommendations for diagnosis in patients who have ischemia with nonobstructive CAD. Recent studies have shown a greater decrease in stress MBF and MPR in patients with three-vessel CAD compared with those in patients with MVD, demonstrating an important role that quantitative stress CMR can play in differentiating these etiologies in patients with stable angina. In cases of hypertrophic cardiomyopathy and cardiac amyloidosis, qPerf CMR aids in early diagnosis of ischemia and in risk assessment. Ischemia also results from alterations in hemodynamics that may occur with valve disease such as aortic stenosis or in cases of heart failure. qPerf CMR has emerged as a useful noninvasive tool for detection of cardiac allograft vasculopathy in patients who have undergone heart transplant. The authors review the basic principles and current primary clinical applications of qPerf CMR

Gain-of-function mutations in CTNNB1, gene encoding for β-catenin, are observed in 25–30

Purpose: To investigate diagnostic accuracy of virtual non contrast (VNC) images, based on dual-source dualenergy CT (dsDECT), for detection of at least moderate steatosis and to define a threshold value to make this diagnosis on VNC. Methods: This single-institution retrospective study included patients who had multi-phasic protocol dsDECT. Regions of interests were placed in different segments of the liver and spleen on true non-contrast (TNC), VNC, and portal-venous phase (PVP) images. At least moderate steatosis was defined as liver attenuation (LHU) < 40 HU on TNC. Diagnostic performance of VNC to detect steatosis was determined and the new threshold was tested in a validation cohort. Results: 236 patients were included in training cohort. Mean liver attenuation values were 51.3 +/- 10.8 HU and 58.1 +/- 11.5 HU for TNC and VNC (p < 0.001), with a mean difference (VNC - TNC) of 6.8 +/- 6.9 HU. Correlation between TNC and VNC was strong (r = 0.81, p < 0.001). The AUCs of LHU on VNC for detection of hepatic steatosis were 0.92 (95 % Cl: 0.86-0.98), 0.92 (95 % Cl: 0.87-0.97), 0.92 (95 % Cl: 0.86-0.99), 0.91 (95 % Cl: 0.84-0.97), and 0.87 (95 % Cl: 0.80-0.95) for entire liver, left lateral, left medial, right anterior, and right posterior segments, respectively. VNC had sensitivity/specificity of 100 % /42 % when using a threshold of 40 HU; they were 69 % and 95 %, respectively, when using optimized threshold of 46 HU. This threshold showed similar performance in validation cohort (n = 80). Conclusions: Hepatic attenuation on VNC has promising performance for detection of at least moderate steatosis. Proposed threshold of 46 HU provides high specificity and moderate sensitivity to detect steatosis.

BACKGROUND:In patients with bicuspid aortic valve (BAV), 4D flow MRI can quantify regions exposed to abnormal aortic hemodynamics, including high wall shear stress (WSS), a known stimulus for arterial wall dysfunction. However, the long-term multiscan reproducibility of 4D flow MRI-derived hemodynamic parameters is unknown. PURPOSE:To investigate the long-term stability of 4D flow MRI-derived peak velocity, WSS, and WSS-derived heatmaps in patients with BAV undergoing multiyear surveillance imaging. STUDY TYPE:Retrospective. POPULATION:20 BAV patients (mean age 48.4 ± 13.9 years; 14 males) with five 4D flow MRI scans, with intervals of at least 6 months between scans, and 125 controls (mean age: 50.7 ± 15.8 years; 67 males). FIELD STRENGTH/SEQUENCE:1.5 and 3.0T, prospectively ECG and respiratory navigator-gated aortic 4D flow MRI. ASSESSMENT:Automated AI-based 4D flow analysis pipelines were used for data preprocessing, aorta 3D segmentation, and quantification of ascending aorta (AAo) peak velocity, peak systolic WSS, and heatmap-derived relative area of elevated WSS compared to WSS ranges in age and sex-matched normative control populations. Growth rate was derived from the maximum AAo diameters measured on the first and fifth MRI scans. STATISTICAL TESTS:One-way repeated measures analysis of variance. P < 0.05 indicated significance. RESULTS:One hundred 4D flow MRI exams (five per patient) were analyzed. The mean total follow-up duration was 5.5 ± 1.1 years, and the average growth rate was 0.3 ± 0.2 mm/year. Peak velocity, peak systolic WSS, and relative area of elevated WSS did not change significantly over the follow-up period (P = 0.64, P = 0.69, and P = 0.35, respectively). The patterns and areas of elevated WSS demonstrated good reproducibility on semiquantitative assessment. CONCLUSION:4D flow MRI-derived peak velocity, WSS, and WSS-derived heatmaps showed good multiyear and multiscan stability in BAV patients with low aortic growth rates. These findings underscore the reliability of these metrics in monitoring BAV patients for potential risk of dilation. LEVEL OF EVIDENCE:3 TECHNICAL EFFICACY: Stage 1.

Hip osteoarthritis (OA) is common and has detrimental consequences on mobility and quality of life . There is some concern of chondrotoxic effects of the steroid, as well as the anesthetic, with the risk of OA progression, also known as rapidly progressive or destructive osteoarthritis and was recently termed as rapidly progressive idiopathic arthritis (RPIA). The following article summarizes the pathophysiology of RPIA with the recent literature review on its prevalence. We will also provide our results regarding its prevalence and risk factors in our population, which is representative of an urban and suburban American population.

To determine a reliable threshold common duct diameter on CT, in combination with other ancillary CT and clinical parameters, at which the likelihood of pathology requiring further imaging or intervention is increased in post-cholecystectomy patients. In this IRB approved retrospective study, two attending radiologists independently reviewed CT imaging for 118 post-cholecystectomy patients, who were subsequently evaluated with MRCP, ERCP, or EUS, prompted by findings on the CT and clinical status. Measurements of the common duct (CD) were obtained at the porta hepatis, distal duct, and point of maximal dilation on axial and coronal CT scans. Patients were grouped by whether they required intervention after follow-up imaging. Pertinent baseline lab values and patient demographics were reviewed. Of the 118 post-cholecystectomy patients, 38 patients (31

Focal nodular hyperplasia-like (FNH-like) nodules are hepatocellular lesions with similar radiologic and pathologic features as typical FNH but occur within an abnormal liver. They arise due to alteration of hepatic vasculature at both the microscopic and macroscopic levels. Although these nodules are not thought to have malignant potential, their imaging features overlap with premalignant and malignant lesions including hepatocellular carcinoma (HCC) and arise in patients who may be at risk for HCC, posing a diagnostic and management dilemma. It is important to consider these benign entities when reviewing liver imaging of patients at risk for HCC to reduce unnecessary interventions.

Focal nodular hyperplasia-like (FNH-like) nodules are hepatocellular lesions with similar radiologic and pathologic features as typical FNH but occur within an abnormal liver. They arise due to alteration of hepatic vasculature at both the microscopic and macroscopic levels. Although these nodules are not thought to have malignant potential, their imaging features overlap with premalignant and malignant lesions including hepatocellular carcinoma (HCC) and arise in patients who may be at risk for HCC, posing a diagnostic and management dilemma. It is important to consider these benign entities when reviewing liver imaging of patients at risk for HCC to reduce unnecessary interventions.

Objective This study aimed to assess the diagnostic accuracy of magnetic resonance elastography (MRE) in detecting hepatic fibrosis and determining clinically relevant stiffness cutoff values per stage of fibrosis. Methods This retrospective study assessed 1488 hepatic MRE evaluations performed at a single institution for 5 years. Mean liver stiffness measurements were collected from 282 patients who had an MRE study within 1 year of histopathologic analysis. Areas under receiver operating characteristic curves were calculated for each stage of fibrosis with nonparametric ordinal measures of accuracy, and Youden Index was determined. Results Mean liver stiffness measurement values were as follows: F0, 2.5± 0.55 kPa; F1, 3.1± 0.80 kPa; F2, 3.4±0.95 kPa; F3, 4.7±1.44 kPa; and F4, 7.9± 2.64 kPa. Nonparametric ordinal measures of accuracy per fibrosis stage were as follows: F0: 0.934, P < 0.001; F0–F1: 0.917, P < 0.001; F0–F2: 0.944, P < 0.001; and F0–F3: 0.941, P < 0.001. Youden Index values for fibrosis stages F2, F3, and F4 were 3.9, 4.0, and 4.5 kPa, respectively. Conclusions Magnetic resonance elastography is an accurate diagnostic tool in assessing liver fibrosis.

Hemoperitoneum caused by ovarian cyst rupture may necessitate intervention. The literature is lacking in descriptions of CT findings that help guide patient management. The purpose of this study is to consider CT findings associated with a need for intervention (surgical or interventional radiology management) versus conservative treatment (observation, pain management, and blood transfusions). Two radiologists retrospectively and independently reviewed 103 CTs of pre-menopausal women who presented with acute hemoperitoneum related to ruptured ovarian cysts between January 2010 and January 2019. The following imaging features were assessed: ovarian cyst characteristics, sentinel clot, contrast extravasation, and hemoperitoneum size. Findings were correlated with patient demographics, clinical parameters, and management with surgery/interventional radiology procedure (intervention group) versus conservative management (conservative group). Of the 103 patients with hemoperitoneum from cyst rupture, 16% (n = 16) required intervention, and 84% underwent conservative treatment (n = 87). Length of stay (p = .008) was higher in the intervention group. Statistically significant CT findings in the intervention versus conservative group included (p-value reader 1/p-value reader 2) greatest AP dimension of hemoperitoneum (p = .001/p = 0.02), posterior cul-de-sac AP dimension (p = 0.03/p = .006), total cul-de-sac AP dimension (p = .002/p = .007), and number of spaces with hemoperitoneum (p = .01/p = .02). There was good to excellent inter-reader agreement for these findings (ICC 0.68–0.91). Active contrast extravasation was significant for one reader (p = .02) with poor inter-reader agreement (ICC 0.36). In utilizing ROC curves, thresholds of 107 mm (greatest axial AP dimension of hemoperitoneum) yielded a sensitivity and specificity of 0.81 and 0.62 for reader 1 and 0.69 and 0.55 for reader 2; 45 mm (posterior cul-de-sac AP dimension) yielded a sensitivity and specificity of 0.75 and 0.63 for reader 1 and 0.94 and 0.49 for reader 2; 70 mm (total cul-de-sac AP dimension) yielded a sensitivity and specificity of 0.75 and 0.64 for reader 1 and 0.75 and 0.50 for reader 2; and greater than 5 spaces yielded a sensitivity and specificity of 0.75 and 0.58 for reader 1 and 0.69 and 0.70 for reader 2. CT findings associated with intervention in hemoperitoneum due to ovarian cyst rupture include size of hemoperitoneum, number of abdominopelvic spaces with hemoperitoneum, and contrast extravasation.

To evaluate performance of 3D magnetic resonance elastography (MRE) using spin-echo echo-planar imaging (seEPI) for assessment of hepatic stiffness compared with 2D gradient-recalled echo (GRE) and 2D seEPI sequences. Fifty-seven liver MRE examinations including 2D GRE, 2D seEPI, and 3D seEPI sequences were retrospectively evaluated. Elastograms were analyzed by 2 radiologists and polygonal regions of interests (ROIs) were drawn in 2 different fashions: “curated” ROI (avoiding liver edge, major vessels, and areas of wave interferences) and “non-curated” ROI (including largest cross section of liver, to assess the contribution of artifacts). Liver stiffness measurement (LSM) was calculated as the arithmetic mean of individual stiffness values for each technique. For 3D MRE, LSMs were also calculated based on 4 slices (“abbreviated LSM”). Intra-patient variations in LSMs and different methods of ROI placement were assessed by univariate tests. A p-value of < 0.05 was set as a statistically significant difference. Mean surface areas of the ROIs were 50,723 mm2, 12,669 mm2, 5814 mm2, and 10,642 mm2 for 3D MRE, abbreviated 3D MRE, 2D GRE, and 2D seEPI, respectively. 3D LSMs based on curated and non-curated ROIs showed no clinically significant difference, with a mean difference less than 0.1 kPa. Abbreviated 3D LSMs had excellent correlation with 3D LSMs based on all slices (r = 0.9; p < 0.001) and were not significantly different (p = 0.927). 3D MRE allows more reproducible measurements due to its lower susceptibility to artifacts and provides larger areas of parenchyma, enabling a more comprehensive evaluation of the liver.

Liver cancer is the fastest-growing cause of cancer deaths in the United States and is a complex disease. The response of hepatocellular carcinoma (HCC) to treatment can be variable. Predicting response to determine the most effective therapy is an active area of research. Our understanding of underlying factors which drive response to therapy is continually increasing. As more therapies for the treatment of this disease evolve, it is crucial to identify and match the ideal therapy for a particular tumor and patient. The potential predicative imaging features of tumor behavior, while of research interest, have not been validated for clinical use and do not currently inform treatment planning. If further validated though, prognostic features may be used in the future to personalize treatment plans according to individual patients and tumors. Unexpected post-treatment responses such as potential tumor biology changes and abscopal effect which are important to be aware of. This review is intended for radiologists who routinely interpret post treatment HCC imaging and is designed to increase their cognizance about how HCC tumor biology drives response to therapy and explore rare responses to therapy.

Primary bone lymphoma is a rare entity and it usually occurs in long bones. Primary mandibular involvement is very rare, and it usually shows unspecific features, mimicking odontogenic inflammatory lesions. We present the unusual case of a diffuse large B-cell lymphoma (DLBCL) of the right mandibular body in a 91-year-old woman, who presented with acute pain in the mandibular region initially suspicious for odontogenic abscess. No significant findings were seen on orthopantomography (OPG) and her almost complete edentulism made the diagnosis of abscess unlikely. Computed tomography and magnetic resonance images showed an expansive mass around the right mandibular body with erosion of cortical bone and involving the right mandibular canal and nerve. Final diagnosis of DLBCL was pathologically proven. The presence of odontogenic-like pain in nearly complete edentulism should be suspicious for malignancy, and it needs further diagnostic workup despite the absence of signs on OPG.

Purpose To reconstruct virtual MR elastography (MRE) images based on traditional MRI inputs with a machine learning algorithm. Materials and Methods In this single-institution, retrospective study, 149 patients (mean age, 58 years ± 12 [standard deviation]; 71 men) with nonalcoholic fatty liver disease who underwent MRI and MRE between January 2016 and January 2019 were evaluated. Nine conventional MRI sequences and clinical data were used to train a convolutional neural network to reconstruct MRE images at the per-voxel level. The architecture was further modified to accept multichannel three-dimensional inputs and to allow inclusion of clinical and demographic information. Liver stiffness and fibrosis category (F0 [no fibrosis] to F4 [significant fibrosis]) of reconstructed images were assessed by using voxel- and patient-level agreement by correlation, sensitivity, and specificity calculations; in addition, classification by receiver operator characteristic analyses was performed, and Dice score was used to evaluate hepatic stiffness locality. Results The model for predicting liver stiffness incorporated four image sequences (precontrast T1-weighted liver acquisition with volume acquisition [LAVA] water and LAVA fat, 120-second-delay T1-weighted LAVA water, and single-shot fast spin-echo T2 weighted) and clinical data. The model had a patient-level and voxel-level correlation of 0.50 ± 0.05 and 0.34 ± 0.03, respectively. By using a stiffness threshold of 3.54 kPa to make a binary classification into no fibrosis or mild fibrosis (F0-F1) versus clinically significant fibrosis (F2-F4), the model had sensitivity of 80% ± 4, specificity of 75% ± 5, accuracy of 78% ± 3, area under the receiver operating characteristic curve of 84 ± 0.04, and a Dice score of 0.74. Conclusion The generation of virtual elastography images is feasible by using conventional MRI and clinical data with a machine learning algorithm.Keywords: MR Imaging, Abdomen/GI, Liver, Cirrhosis, Computer Applications/Virtual Imaging, Experimental Investigations, Feature Detection, Classification, Reconstruction Algorithms, Supervised Learning, Convolutional Neural Network (CNN) Supplemental material is available for this article. © RSNA, 2021.