Host space, not energy or symbiont size, constrains feather mite abundance across passerine bird species.

Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constrains symbiont populations. We parameterized metabolic theory equations to investigate how bird species' body size and the body size of their feather mites relate to mite abundance according to four potential energy (uropygial gland size) and space constraints (wing area, total length of barbs and number of feather barbs). Predictions were compared with the empirical scaling of feather mite abundance across 106 passerine bird species (26,604 individual birds sampled), using phylogenetic modelling and quantile regression. Feather mite abundance was strongly constrained by host space (number of feather barbs) but not by energy. Moreover, feather mite species' body size was unrelated to the body size of their host species. We discuss the implications of our results for our understanding of the bird-feather mite system and for symbiont abundance in general.

Multimodality Imaging Appearance of Intrapericardial Paragangliomas.

Paragangliomas are neuroendocrine tumors of the sympathetic and parasympathetic nervous system that originate from neural crest cells. Less than 1% of paragangliomas are found in the heart, originating from intrinsic cardiac ganglia cells in the posterior wall the atria, atrioventricular groove, and along the root of the great vessels. A 10-year review of our institution's database identified nine patients who had documented intrapericardial paragangliomas. We describe the multimodality imaging appearance of these tumors. The most common findings include embedment and wrapping around the great vessels and atrioventricular groove within the confines of the pericardium, markedly avid heterogeneous enhancement, distinct engorged neovascularization, and in large lesions, central low attenuation areas compatible with hemorrhage, necrosis, or cystic degeneration.

Cardiac gated multidetector computed tomography (MDCT) to determine valvular leaflet thrombosis and leaflet restriction.

The evaluation of patients following aortic valve replacement has evolved, with multiple imaging modalities available that complement each other and permit better and prompt delineation of specific structural or functional valve complications. Multidetector computed tomography (MDCT) is one of the diagnostic modalities with significant technologic advancements that have made possible to evaluate high detail of the moving heart. The ability to deliver three-dimensional and multiplanar dynamic imaging with fine detail has demonstrated the technique is well suited to investigate valve complications. In this review article, we focus on some of the most contributing roles of MDCT in the diagnosis of complications associated with valvular pathology.

Computed tomography findings in septic pulmonary embolism: A case report and literature review.

This case report describes the findings of septic pulmonary embolism (SPE) in a young adult male with a history of intravenous drug use who initially presented with signs and symptoms of acute sepsis. The patient underwent evaluation by computed tomography (CT) imaging as well as blood cultures and echocardiography, which confirmed the diagnosis of SPE secondary to Staphylococcus aureus positive bacterial endocarditis. In this case report, we discuss the presentation and characteristic CT imaging findings of SPE as well as highlight the value of this imaging modality in the timely diagnosis and management of this urgent condition.

Pitfalls in the imaging of pulmonary embolism.

Pulmonary embolism (PE) can present with a wide spectrum of clinical symptoms that can overlap considerably with other cardiovascular diseases. To avoid PE related morbidity and mortality, it is vital to identify this disease accurately and in a timely fashion. Several clinical criteria have been developed to standardize the diagnostic approach for patients with suspected PE. Computed tomographic pulmonary angiogram has significantly improved the detection of pulmonary embolism and is considered the imaging modality of choice to diagnose this disease. However, there are several potential pitfalls associated with this modality which can make diagnosis of PE challenging. In this review, we will discuss various pitfalls routinely encountered in the diagnostic work up of patients with suspected PE, approaches to mitigate these pitfalls and incidental pulmonary embolism.

Corrigendum to 'Pulmonary vein occlusion: A delayed complication following radio frequency ablation for atrial fibrillation' [Radiology Case Reports 16 (2021) 3666-3671].

[This corrects the article DOI: 10.1016/j.radcr.2021.09.015.].

Pitfalls and Pearls in Esophageal Carcinoma.

The management of patients with esophageal carcinoma (EC) requires accurate clinical staging and post-therapeutic evaluation. Currently, esophagogastroduodenoscopy/endoscopic ultrasound (EGD/EUS), endoscopic ultrasound-fine needle aspiration (EUS-FNA), computed tomography (CT), 18F- fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) and magnetic resonance (MR) imaging are used for the initial clinical staging, evaluation of therapeutic response and follow-up in patients with EC. However, there are limitations and pitfalls that are commonly encountered when imaging these patients that can limit accurate assessment. Knowledge of the limitations and pitfalls associated with the use of these different imaging modalities is essential in avoiding misinterpretation and guaranteeing the appropriate management for patient with EC.

Cardiac MRI for Evaluation of Right Heart Function before and after Catheter-directed Therapy in Submassive Pulmonary Embolism: A Prospective Study of Feasibility and Potential Utility.

Cardiac MRI is clinically feasible in the setting of submassive pulmonary embolism and is able to demonstrate measurable differences of right heart function before and after catheter-directed therapy.

Pulmonary vein occlusion: A delayed complication following radiofrequency ablation for atrial fibrillation.

This case reports demonstrates the rare but potentially serious complication of pulmonary vein stenosis and subsequent thrombosis diagnosed two years after radiofrequency ablation of the pulmonary veins for atrial fibrillation. Pulmonary vein stenosis can remain asymptomatic until significant occlusion occurs, after which it can present with a variety of symptoms, mimicking a myriad of cardiovascular and pulmonic pathologies. Early diagnosis and treatment rely on consistent follow up using appropriate diagnostic imaging modalities and is paramount in preventing severe complications.

HRCT Diagnosis of Pleuroparenchymal fibroelastosis: Report of two cases.

Pleuroparenchymal fibroelastosis (PPFE) is a rare idiopathic interstitial pneumonia that is often underdiagnosed on computed tomography scans. The disease process involves a combination of fibrosis involving the visceral pleura and fibroelastic changes within the subpleural lung parenchyma. Although definitive diagnosis is based on pathological evaluation, this is often not feasible and pattern recognition on CT as "definite PPFE" or "consistent with PPFE" is important given that sub group of patients will undergo rapid progression with clinical deterioration.

Aortic aneurysms and dissections: Unmet needs from physicians and engineers perspectives.

The treatment of aortic disease is complex, requiring cardiothoracic and vascular surgeons to make pre-, post- and intraoperative decisions directly influencing patient survival and well-being. Despite tremendous advancement in vascular surgery and endovascular techniques in the last two decades, along with the abundance of research in the field, many unmet needs and unanswered questions remain. Tight collaboration between engineers and physicians is a keystone in translating new tools, techniques, and devices into practice. Here, we have gathered our perspective, as physicians and engineers, in several pressing issues associated with the diagnosis and treatment of aortic aneurysms and dissection, referring to the current knowledge and practice, signifying unmet needs as well as future directions.

Esophageal Cancer: Tumor-Node-Metastasis Staging.

Esophageal cancer is an uncommon malignancy that ranks sixth in terms of mortality worldwide. Squamous cell carcinoma is the predominant histologic subtype worldwide whereas adenocarcinoma represents the majority of cases in North America, Australia, and Europe. Esophageal cancer is staged using the American Joint Committee on Cancer and the International Union for Cancer Control TNM system and has separate classifications for the clinical, pathologic, and postneoadjuvant pathologic stage groups. The determination of clinical TNM is based on complementary imaging modalities, including esophagogastroduodenoscopy/endoscopic ultrasound; endoscopic ultrasound-fine-needle aspiration; computed tomography of the chest, abdomen, and pelvis; and fluorodeoxyglucose PET/computed tomography.

Pitfalls and Misinterpretations of Cardiac Findings on PET/CT Imaging: A Careful Look at the Heart in Oncology Patients.

Positron emission tomography (PET) computed tomography (CT) with 2-[fluorine-18] fluoro-2-deoxy-d-glucose (FDG) has been established as an effective modality for evaluation of cancer. Interpretations of patterns of physiologic 18F-FDG uptake by the heart is particularly difficult given the wide normal variations of 18F-FDG metabolic activity observed. Atypical patterns of focal or diffuse physiologic cardiac 18F-FDG uptake and post-therapeutic effects after radiation therapy, systemic diseases, or cardiomyopathy may also be confused with malignant disease on 18F-FDG PET/CT. In this article, we review the variations of normal cardiac 18F-FDG uptake observed in oncology patients and the appearances of other patterns of pathologic metabolic activity, related or not related to the malignancy being investigated, that may lead to false-negative and false-positive results.

Diagnosing conduit leak after esophagectomy for esophageal cancer by computed tomography leak protocol and standard esophagram: Is old school still the best?

The imaging modalities available to evaluate anastomotic leak complicating esophagectomy include CT-Esophageal Protocol (CTEP) and esophagram. The purpose of this study was to compare the performance of these two modalities, alone or in combination, with the final diagnosis of leak established by endoscopy, surgery and/or the clinical course and evaluate management implications.

18FDG-PET/CT is useful in the follow-up of surgically treated patients with oesophageal adenocarcinoma.

OBJECTIVE: The purpose of this study was to evaluate fludeoxyglucose-positron emission ;tomography/CT's (FDG-PET/CT) performance in the follow ;up of patients with surgically treated oesophageal adenocarcinoma. METHODS: The follow-up FDG-PET/CT scans of 162 consecutive patients with surgically treated oesophageal adenocarcinoma were retrospectively reviewed. Histopathological and/or imaging examinations confirmed recurrent disease. The accuracy, sensitivity, specificity and negative and positive predictive values were calculated. RESULTS: Recurrence occurred in 71 (43%) patients, usually within the first year following surgery (60%) and in more than one site (76%). The sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of FDG-PET/CT for anastomotic recurrence were 77, 76, 16, 98 and 76%; for regional nodal recurrence were 88, 85, 43, 97 and 86%; and for distant metastatic recurrence were: 97, 96, 91, 99 and 96%. In 5 of the 42 patients (12%) with distant metastases, the metastatic sites were outside the area covered by a conventional follow-up chest-abdomen CT and in 4 patients (9%) metastases were barely perceptible on the CT component of the FDG-PET/CT and consequently were unlikely to be detected without the aid of the FDG uptake. CONCLUSION: FDG PET/CT is accurate in detecting oesophageal adenocarcinoma recurrence, especially within the first post-operative year when most recurrences occur, and is useful in identifying patients with a solitary metastasis. Advances in knowledge: FDG-PET/CT should be considered as a valuable tool in the routine follow ;up of surgically treated oesophageal cancer patients within the first 2 years after surgery.

Positron Emission Tomography/Computed Tomography in Esophageal Carcinoma: Applications and Limitations.

Squamous cell carcinoma and adenocarcinoma represent approximately 98% of esophageal malignant tumors. During the last 30 years, the incidence of adenocarcinoma has increased in Western countries (including the USA) where adenocarcinoma currently represents more than 60% of esophageal malignancies, although, worldwide, squamous cell carcinoma continues to be the predominant histologic type. Integrated positron emission tomography or computed tomography with 2-[fluorine18] fluro-2-deoxy-d-glucose is used in many institutions routinely as a tool in the initial staging and then repeated after therapy for the assessment of response to neoadjuvant therapy and detection of recurrent disease in patients with esophageal carcinoma. As with any other imaging modality, 2-[fluorine18] fluro-2-deoxy-d-glucose-positron emission tomography or computed tomography has strengths and limitations that should be understood in order to maximize its utility.

Intra- and Extra-Thoracic Muscle Flaps and Chest Wall Reconstruction Following Resection of Thoracic Tumors.

Improvements in surgical technique over the last decade enable surgeons to perform extensive resection and reconstruction in patients presenting with tumors involving the soft tissue or bony structures of the chest wall. The type of surgical resection and its size, depend on the type of tumor resected and its location. In addition to providing a better esthetic result, the reconstruction restores support and functionality of the thoracic cage. The approach to chest wall repair includes primary closure or reconstruction by using transposition flaps, free flaps, prosthetic material, or a mixture of a flap and prosthetic material.

Characterizing proton-activated materials to develop PET-mediated proton range verification markers.

Conventional proton beam range verification using positron emission tomography (PET) relies on tissue activation alone and therefore requires particle therapy PET whose installation can represent a large financial burden for many centers. Previously, we showed the feasibility of developing patient implantable markers using high proton cross-section materials ((18)O, Cu, and (68)Zn) for in vivo proton range verification using conventional PET scanners. In this technical note, we characterize those materials to test their usability in more clinically relevant conditions. Two phantoms made of low-density balsa wood (~0.1 g cm(-3)) and beef (~1.0 g cm(-3)) were embedded with Cu or (68)Zn foils of several volumes (10-50 mm(3)). The metal foils were positioned at several depths in the dose fall-off region, which had been determined from our previous study. The phantoms were then irradiated with different proton doses (1-5 Gy). After irradiation, the phantoms with the embedded foils were moved to a diagnostic PET scanner and imaged. The acquired data were reconstructed with 20-40 min of scan time using various delay times (30-150 min) to determine the maximum contrast-to-noise ratio. The resultant PET/computed tomography (CT) fusion images of the activated foils were then examined and the foils' PET signal strength/visibility was scored on a 5 point scale by 13 radiologists experienced in nuclear medicine. For both phantoms, the visibility of activated foils increased in proportion to the foil volume, dose, and PET scan time. A linear model was constructed with visibility scores as the response variable and all other factors (marker material, phantom material, dose, and PET scan time) as covariates. Using the linear model, volumes of foils that provided adequate visibility (score 3) were determined for each dose and PET scan time. The foil volumes that were determined will be used as a guideline in developing practical implantable markers.