Pulmonary Histoplasmosis Complicated by Nonvalvular Right Ventricular Wall Histoplasma capsulatum Endocarditis.

Histoplasmosis is commonly a self-limited fungal disease that primarily affects the lung and reticuloendothelial system. Cardiac involvement by histoplasmosis is uncommon. In this report, we provide a detailed description of severe pulmonary histoplasmosis complicated by the disease involvement of the free wall of the right ventricle. A 55-year-old female presented with cough, fevers, dyspnea, and 30-pound unintentional weight loss in 6 months. Her past medical history was significant for supraventricular tachycardia with permanent pacemaker implantation. Imaging studies revealed an intracardiac mass accompanied by mediastinal lymphadenopathy and bilateral lung nodules. Endobronchial ultrasound-guided transbronchial needle aspiration of station 4R lymph nodes revealed numerous yeast forms, morphologically consistent with Histoplasma capsulatum. The diagnosis was further corroborated by the elevated titers of serum antibodies against Histoplasma capsulatum. The right ventricular mass debulking with biopsy showed necrotizing granulomatous inflammation involving nonvalvular endocardium and myocardium of the free wall of the right ventricle. The report documents an unusual presentation of pulmonary histoplasmosis accompanied by nonvalvular endocarditis and suggests a possible association between the site of the cardiac infection and the presence of a permanent intravascular pacer device.

A Case of Mediastinal Carcinosarcoma With Beta-HCG Production and KRAS Mutation.

Carcinosarcomas of mediastinum are rare and only few well-documented cases are available in the literature. We report a detailed description of mediastinal carcinosarcoma with unique clinical manifestations and immunohistochemical and molecular profiles. A 44-year-old female with an enlarging anterior mediastinal mass was found to have a positive pregnancy test. Thoracoscopic biopsy revealed that the mass represented a carcinosarcoma with adenocarcinoma and chondrosarcoma components. The tumor focally expressed beta-HCG by immunohistochemistry and had KRAS G12A missense mutation by next generation sequencing. The case documents a rare presentation of carcinosarcoma within the mediastinum with uncommon paraneoplastic syndrome and genetic profile. Awareness of these unusual clinical and pathological manifestations of the tumor will help in reaching correct diagnosis and proper management of such patients.

Pulmonary artery size on computed tomography is associated with major morbidity after pulmonary lobectomy.

OBJECTIVE: To investigate the relationship of pulmonary artery diameter (PAD) measured by computed tomography (CT) with outcomes following lobectomy. METHODS: Records of patients undergoing pulmonary lobectomy for lung cancer between 2011 and 2018 were reviewed. Baseline characteristics and postoperative outcome data were derived from the institutional Society of Thoracic Surgeons database. Luminal diameter of the central pulmonary arteries and ascending aorta were measured on preoperative CTs. Logistic regression analyses were performed to test the association of PAD with complications. RESULTS: A total of 736 lobectomy patients were included, who had a preoperative CT scan (25% with contrast, 75% noncontrast) available for review. A total of 141 (19.2%) patients had an enlarged main PAD ≥30 mm, and 58 (7.9%) patients had a main PAD that was larger than the ascending aorta (PA/ascending aorta ratio > 1). The right or left PAD on the surgical side was associated with major complication (odds ratio per mm, 1.12; 95% confidence interval, 1.05-1.18; P < .001), unexpected intensive care unit admission (odds ratio per millimeter, 1.11; 95% confidence interval, 1.04-1.19; P = .002), and 30-day mortality (odds ratio per millimeter, 1.25; 95% confidence interval, 1.06-1.46; P = .007). On multivariable analysis, adjusted for cardiovascular comorbidities, pulmonary function, and the operative approach, surgical side PAD remained an independent factor associated with major complication. CONCLUSIONS: CT-based measurements of the PAD on the operative side may inform of the about the risk of major complications after lobectomy. Review of PA size on preoperative CT scans may help identify patients who would benefit from formal evaluation of PA pressures to improve the operative risk assessment.

Are quantitative features of lung nodules reproducible at different CT acquisition and reconstruction parameters?

Consistency and duplicability in Computed Tomography (CT) output is essential to quantitative imaging for lung cancer detection and monitoring. This study of CT-detected lung nodules investigated the reproducibility of volume-, density-, and texture-based features (outcome variables) over routine ranges of radiation dose, reconstruction kernel, and slice thickness. CT raw data of 23 nodules were reconstructed using 320 acquisition/reconstruction conditions (combinations of 4 doses, 10 kernels, and 8 thicknesses). Scans at 12.5%, 25%, and 50% of protocol dose were simulated; reduced-dose and full-dose data were reconstructed using conventional filtered back-projection and iterative-reconstruction kernels at a range of thicknesses (0.6-5.0 mm). Full-dose/B50f kernel reconstructions underwent expert segmentation for reference Region-Of-Interest (ROI) and nodule volume per thickness; each ROI was applied to 40 corresponding images (combinations of 4 doses and 10 kernels). Typical texture analysis metrics (including 5 histogram features, 13 Gray Level Co-occurrence Matrix, 5 Run Length Matrix, 2 Neighboring Gray-Level Dependence Matrix, and 3 Neighborhood Gray-Tone Difference Matrix) were computed per ROI. Reconstruction conditions resulting in no significant change in volume, density, or texture metrics were identified as "compatible pairs" for a given outcome variable. Our results indicate that as thickness increases, volumetric reproducibility decreases, while reproducibility of histogram- and texture-based features across different acquisition and reconstruction parameters improves. To achieve concomitant reproducibility of volumetric and radiomic results across studies, balanced standardization of the imaging acquisition parameters is required.

Imaging Evaluation of Lung Transplantation Patients: A Time and Etiology-based Approach to High-resolution Computed Tomography Interpretation.

Lung transplantation is an established therapeutic option for patients with irreversible end-stage pulmonary disease limiting life expectancy and quality of life. Common indications for lung transplantation include chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, pulmonary arterial hypertension, and alpha-1 antitrypsin deficiency. Complications of lung transplantation can be broadly divided etiologically into surgical, infectious, immunologic, or neoplastic. Moreover, specific complications often occur within a certain time interval following surgery, which can be broadly classified as early (<6 wk), intermediate (6 wk to 6 mo), and late (>6 mo). Thus, each group of complications can further be categorized on the basis of the time continuum from transplantation. Imaging, primarily by high-resolution computed tomography, plays a critical role in early diagnosis of complications after lung transplantation. Early recognition of complications by the radiologist, and initiation of therapy, contributes to improved morbidity and mortality. However, accurate diagnosis is only feasible if one has a thorough understanding of the major etiologic categories of complications and how they relate to the time course since transplantation. We review imaging manifestations of lung transplant complications via a framework that includes the following major etiologic categories: surgical; infectious; immunologic; and neoplastic; and the following time frames: surgery to 6 weeks; 6 weeks to 6 months; and beyond 6 months. We propose this approach as a logical, evidence-based algorithm to construct a narrow, optimal differential diagnosis of lung transplantation complications.

Incidence of aortic arch anomalies in patients with thoracic aortic dissections.

BACKGROUND AND AIM OF STUDY: Traditionally aortic arch anomalies have been viewed as a "normal" and clinically insignificant; therefore, they are often overlooked by radiologists and go unreported. Arch anomalies have been reported to occur in 7% to 15% of patients without thoracic aortic aneurysm or dissection. This study aims to define the incidence of aortic arch anomalies in patients with a thoracic aortic dissection (TAD). METHODS: We retrospectively reviewed all patients from 2006 to 2010 with a TAD admitted to a single institution. Thoracic computed tomography images of 176 patients with dissected thoracic aortas and 179 consecutive, unselected age-matched patients without dissection as controls were reviewed to determine the incidence of bovine arch and other arch anomalies. Statistical analysis of demographic data and clinical outcomes was performed to evaluate significant differences between the groups. RESULTS: Arch anomalies occurred in 34% of patients with TAD compared to controls (19%, p = 0.0017). The most common variant was a common origin of the innominate and left common carotid arteries ("bovine" arch) found in 31% of dissection patients compared to 15% in the control group (p = 0.0004). Overall arch anomalies occurred in 27% of all Type A dissections and 39% (p = 0.1409) of all Type B dissections. The association was statistically significant in patients ages 50 to 79 with TAD (36.4%, p = 0.0011) and in African Americans collectively (43.2%, p = 0.0033). CONCLUSIONS: Aortic arch anomalies occur frequently in patients with TAD and therefore may represent a proclivity for this life threatening condition.

Interparietal bone (Os Incae) in craniosynostosis.

The interparietal bone, Os Incae, is formed in a persistent mendosal suture. This suture is a normal variant in the human skull, well-known in anatomy and radiology textbooks. We report 11 children with craniosynostosis in the presence of an interparietal bone, five from Children's Hospital at Montefiore and six children from Children's Hospital Boston. The true incidence of an interparietal bone in patients with craniosynostosis or craniofacial anomalies is not known; nor are there recognized sequelae of an interparietal bone (bathrocephaly). Hypotheses regarding mechanisms that may contribute to the formation of an interparietal bone are discussed.

Regulation of Kv4.3 closed state inactivation and recovery by extracellular potassium and intracellular KChIP2b.

Mechanisms underlying Kv4 channel inactivation and recovery are presently unclear, although there is general consensus that the basic characteristics of these processes are not consistent with Shaker (Kv1) N- and P/C-type mechanisms. Kv4 channels also differ from Shaker in that they can undergo significant inactivation from pre-activated closed-states (closed-state inactivation, CSI), and that inactivation and recovery kinetics can be regulated by intracellular KChIP2 isoforms. To gain insight into the mechanisms regulating Kv4.3 CSI and recovery, we have analyzed the effects of increasing [K(+)](o) from 2 mM to 98 mM in the absence and in the presence of KChIP2b, the major KChIP2 isoform expressed in the mammalian ventricle. In the absence of KChIP2b, high [K(+)](o) promoted Kv4.3 inactivated closed-states and significantly slowed the kinetics of recovery from both macroscopic and closed-state inactivation. Coexpression of KChIP2b in 2 mM [K(+)](o) promoted non-inactivated closed-states and accelerated the kinetics of recovery from both macroscopic and CSI. In high [K(+)](o), KChIP2b eliminated or significantly reduced the slowing effects on recovery. Attenuation of CSI by the S4 charge-deletion mutant R302A, which produced significant stabilization of non-inactivated closed-states, effectively eliminated the opposing effects of high [K(+)](o) and KChIP2b on macroscopic recovery kinetics, confirming that these results were due to alterations of CSI. Elevated [K(+)](o) therefore slows Kv4.3 recovery by stabilizing inactivated closed-states, while KChIP2b accelerates recovery by destabilizing inactivated closed-states. Our results challenge underlying assumptions of presently popular Kv4 gating models and suggest that Kv4.3 possesses novel allosteric mechanisms, which are absent in Shaker, for coupling interactions between intracellular KChIP2b binding motifs and extracellular K(+)-sensitive regulatory sites.