Inter-observer variability of expert-derived morphologic risk predictors in aortic dissection.

OBJECTIVES: Establishing the reproducibility of expert-derived measurements on CTA exams of aortic dissection is clinically important and paramount for ground-truth determination for machine learning. METHODS: Four independent observers retrospectively evaluated CTA exams of 72 patients with uncomplicated Stanford type B aortic dissection and assessed the reproducibility of a recently proposed combination of four morphologic risk predictors (maximum aortic diameter, false lumen circumferential angle, false lumen outflow, and intercostal arteries). For the first inter-observer variability assessment, 47 CTA scans from one aortic center were evaluated by expert-observer 1 in an unconstrained clinical assessment without a standardized workflow and compared to a composite of three expert-observers (observers 2-4) using a standardized workflow. A second inter-observer variability assessment on 30 out of the 47 CTA scans compared observers 3 and 4 with a constrained, standardized workflow. A third inter-observer variability assessment was done after specialized training and tested between observers 3 and 4 in an external population of 25 CTA scans. Inter-observer agreement was assessed with intraclass correlation coefficients (ICCs) and Bland-Altman plots. RESULTS: Pre-training ICCs of the four morphologic features ranged from 0.04 (-0.05 to 0.13) to 0.68 (0.49-0.81) between observer 1 and observers 2-4 and from 0.50 (0.32-0.69) to 0.89 (0.78-0.95) between observers 3 and 4. ICCs improved after training ranging from 0.69 (0.52-0.87) to 0.97 (0.94-0.99), and Bland-Altman analysis showed decreased bias and limits of agreement. CONCLUSIONS: Manual morphologic feature measurements on CTA images can be optimized resulting in improved inter-observer reliability. This is essential for robust ground-truth determination for machine learning models. KEY POINTS: • Clinical fashion manual measurements of aortic CTA imaging features showed poor inter-observer reproducibility. • A standardized workflow with standardized training resulted in substantial improvements with excellent inter-observer reproducibility. • Robust ground truth labels obtained manually with excellent inter-observer reproducibility are key to develop reliable machine learning models.

Thoracic Cardiovascular Complications of Tuberculosis.

ABSTRACT: Mycobacterium infection remains a leading cause of morbidity and mortality worldwide. Although rare, thoracic cardiovascular complications are associated with devastating consequences if not promptly diagnosed using computed tomography. Intrapulmonary complications include tuberculous aortitis, Rasmussen aneurysms, involvement of bronchial and nonbronchial systemic arteries, and thromboembolic events. Extrapulmonary complications include pericarditis, myocarditis, endocarditis, involvement of coronary arteries, annular-subvalvular left ventricle aneurysms and mediastinal fibrosis. This article will review these complications and their computed tomography features.

Radiographic Review of Current Therapeutic and Monitoring Devices in the Chest.

Chest radiographs are obtained as a standard part of clinical care. Rapid advancements in medical technology have resulted in a myriad of new medical devices, and familiarity with their imaging appearance is a critical yet increasingly difficult endeavor. Many modern thoracic medical devices are new renditions of old designs and are often smaller than older versions. In addition, multiple device designs serving the same purpose may have varying morphologies and positions within the chest. The radiologist must be able to recognize and correctly identify the proper positioning of state-of-the-art medical devices and identify any potential complications that could impact patient care and management. To familiarize radiologists with the arsenal of newer thoracic medical devices, this review describes the indications, radiologic appearance, complications, and magnetic resonance imaging safety of each device. ©RSNA, 2018.

CT for evaluation of acute pericardial emergencies in the ED.

Acute pericardial emergencies may present with acute chest pain. Although complete diagnosis and physiological effects of acute pericardial disease may require a combination of different imaging, CT plays a critical role in identifying the cause of chest pain in the ED. Many of these pericardial diseases can be fatal unless emergent treatment is obtained. The presentation can often be non-specific and symptoms can be overlapping with other diseases originating in the thorax or abdomen. Optimizing the CT scan is imperative when acute pericardial disease is suspected from clinical examination or preliminary imaging. The interpreting radiologist needs to be aware of the different entities which represent acute pericardial emergencies requiring urgent therapeutic intervention. Time is the essence, the clock is ticking, and every minute counts!

Pulmonary Tuberculosis: Role of Radiology in Diagnosis and Management.

Tuberculosis is a public health problem worldwide, including in the United States-particularly among immunocompromised patients and other high-risk groups. Tuberculosis manifests in active and latent forms. Active disease can occur as primary tuberculosis, developing shortly after infection, or postprimary tuberculosis, developing after a long period of latent infection. Primary tuberculosis occurs most commonly in children and immunocompromised patients, who present with lymphadenopathy, pulmonary consolidation, and pleural effusion. Postprimary tuberculosis may manifest with cavities, consolidations, and centrilobular nodules. Miliary tuberculosis refers to hematogenously disseminated disease that is more commonly seen in immunocompromised patients, who present with miliary lung nodules and multiorgan involvement. The principal means of testing for active tuberculosis is sputum analysis, including smear, culture, and nucleic acid amplification testing. Imaging findings, particularly the presence of cavitation, can affect treatment decisions, such as the duration of therapy. Latent tuberculosis is an asymptomatic infection that can lead to postprimary tuberculosis in the future. Patients who are suspected of having latent tuberculosis may undergo targeted testing with a tuberculin skin test or interferon-γ release assay. Chest radiographs are used to stratify for risk and to assess for asymptomatic active disease. Sequelae of previous tuberculosis that is now inactive manifest characteristically as fibronodular opacities in the apical and upper lung zones. Stability of radiographic findings for 6 months distinguishes inactive from active disease. Nontuberculous mycobacterial disease can sometimes mimic the findings of active tuberculosis, and laboratory confirmation is required to make the distinction. Familiarity with the imaging, clinical, and laboratory features of tuberculosis is important for diagnosis and management. ©RSNA, 2017.

Minimally Invasive Versus Transcatheter and Surgical Aortic Valve Replacement: A Propensity Matched Study.

BACKGROUND: An increasing number of options exist for the treatment of severe symptomatic aortic stenosis. The study aim was to compare short-term outcomes in patients undergoing surgical aortic valve replacement (SAVR), minimally invasive aortic valve replacement (MIAVR), and transcatheter aortic valve replacement (TAVR). METHODS: A multi-institutional retrospective review of 2,571 patients undergoing SAVR (n = 842), MIAVR via right anterior thoracotomy (n = 699) and TAVR (n = 1,030) between 2011 and 2014 was conducted. TAVR patients were further stratified as either transfemoral (TF) or transapical (TA). Propensity matching was performed between MIAVR and SAVR (384 pairs), MIAVR and TA-TAVR (115 pairs), and MIAVR and TF-TAVR (247 pairs). RESULTS: Total numbers of AVR increased between 2011 and 2014. When stratified by procedure type, MIAVR and TF-TAVR accounted for most of the growth, while TA-TAVR and SAVR each experienced a decreased volume. Propensity matched comparisons of SAVR, TF-TAVR, and TA-TAVR versus MIAVR revealed no difference in 30-day mortality. TF-TAVR versus MIAVR revealed that MIAVR had a decreased rate of stroke (0.4% versus 3.6%, p = 0.02) and increased atrial fibrillation (AF; 19.4% versus 4%, p <0.01). When compared to SAVR, MIAVR had a lower incidence of AF (19% versus 32.6%, p <0.01). MIAVR exhibited decreased ventilation time (27.2 versus 134 h, p = 0.03) and intensive care unit time (63.7 versus 92.7 h, p = 0.02) compared to TA-TAVR. CONCLUSIONS: During recent years, MIAVR and TFTAVR have experienced significant growth in volume with near-comparable short-term outcomes, while SAVR and TA-TAVR volumes have declined. These results underscore the importance of surgeons adopting MIAVR and TF-TAVR techniques in order to offer patients optimal outcomes.

Predictors of intervention and mortality in patients with uncomplicated acute type B aortic dissection.

OBJECTIVE: Patients with uncomplicated acute type B aortic dissection (uATBAD) have historically been managed with medical therapy. Recent studies suggest that high-risk patients with uATBAD may benefit from thoracic endovascular aortic repair. This study aims to determine the predictors of intervention and mortality in patients with uATBAD. METHODS: All patients admitted with uATBAD from 2000 to 2014 were reviewed, and those with computed tomographic angiography imaging were included. Multiplanar reconstruction was used to obtain double orthogonal oblique measurements. All measurements were obtained by a specialized cardiovascular radiologist (D.O.). The maximum aortic diameter, proximal descending thoracic aorta false lumen (FL) diameter, and area were recorded. Outcomes, including the need for intervention and mortality, were tracked over time. Data were analyzed by stratified Kaplan-Meier and multiple Cox regression analysis using SAS v 9.4 (SAS Institute, Cary, NC). RESULTS: During the study period, 294 patients with uATBAD were admitted with 156 having admission computed tomographic angiography imaging available for analysis. The cohort had an average age of 60.6 years (±13.6 years); 60% were males. The average follow-up time was 3.7 years (interquartile range, 2.1-6.9). A stratified analysis demonstrated the most sensitive cutoff for mortality was aortic diameter >44 mm (P < .01), and it appeared to be a threshold effect with minimal additional information added by finer size stratification. FL diameter did not predict mortality in our series (P = .36). Intervention-free survival, alternatively, appeared to decrease over the range of diameters from 35 to 44 mm (P < .01). An FL diameter >22 mm was associated with decreased intervention-free survival (P < .04). Age >60 years on admission also demonstrated decreased survival compared with those ≤60 years of age (P < .01). Diameter >44 mm persisted as a risk factor for mortality (hazard ratio, 8.6; P < .01) after adjustment for diabetes (6.7; P < .01), age (1.06/y; P < .01), history of stroke (5.4; P < .01), connective tissue disorder (2.3; P < .01), and syncope on admission (9.5; P < .04). The 1-, 5-, and 10-year intervention rate for patients with admission aortic diameter >44 mm was 18.8%, 29.5%, and 50.3%, respectively, compared with 4.8%, 13.3%, and 13.3% in the ≤44 mm group (P < .01). CONCLUSIONS: Aortic diameter >44 mm is a predictor of mortality after adjustment for other significant risk factors. Age >60 years on admission is a predictor of mortality. An FL diameter >22 mm as well as those with maximum aortic diameter >44 mm on admission were associated with decreased intervention-free survival. Patients with these high-risk criteria may benefit from thoracic endovascular aortic repair. Further studies are needed to further define those patients at highest risk and, thus, most likely to benefit from early intervention.

Hypertrophic Cardiomyopathy from A to Z: Genetics, Pathophysiology, Imaging, and Management.

Hypertrophic cardiomyopathy (HCM) is a heterogeneous group of diseases related to sarcomere gene mutations exhibiting heterogeneous phenotypes with an autosomal dominant mendelian pattern of inheritance. The disorder is characterized by diverse phenotypic expressions and variable natural progression, which may range from dyspnea and/or syncope to sudden cardiac death. It is found across all racial groups and is associated with left ventricular hypertrophy in the absence of another systemic or cardiac disease. The management of HCM is based on a thorough understanding of the underlying morphology, pathophysiology, and clinical course. Imaging findings of HCM mirror the variable expressivity and penetrance heterogeneity, with the added advantage of diagnosis even in cases where a specific mutation may not yet be found. The diagnostic information obtained from imaging varies depending on the specific stage of HCM-phenotype manifestation, including the prehypertrophic, hypertrophic, and later stages of adverse remodeling into the burned-out phase of overt heart failure. However, subtle or obvious, these imaging findings become critical components in diagnosis, management, and follow-up of HCM patients. Although diagnosis of HCM traditionally relies on clinical assessment and transthoracic echocardiography, recent studies have demonstrated increased utility of multidetector computed tomography (CT) and particularly cardiac magnetic resonance (MR) imaging in diagnosis, phenotype differentiation, therapeutic planning, and prognostication. In this article, we provide an overview of the genetics, pathophysiology, and clinical manifestations of HCM, with the spectrum of imaging findings at MR imaging and CT and their contribution in diagnosis, risk stratification, and therapy.

Infectious Diseases of the Heart: Pathophysiology, Clinical and Imaging Overview.

Myriad infectious organisms can infect the endocardium, myocardium, and pericardium, including bacteria, fungi, parasites, and viruses. Significant cardiac infections are rare in the general population but are associated with high morbidity and mortality as well as increased risk in certain populations, such as the elderly, those undergoing cardiac instrumentation, and intravenous drug abusers. Diagnostic imaging of cardiac infections plays an important role despite its variable sensitivity and specificity, which are due in part to the nonspecific manifestations of the central inflammatory process of infection and the time of onset with respect to the time of imaging. The primary imaging modality remains echocardiography. However, cardiac computed tomography and magnetic resonance (MR) imaging have emerged as the modalities of choice wherever available, especially for diagnosis of complex infectious complications including abscesses, infected prosthetic material, central lines and instruments, and the cryptic manifestations of viral and parasitic diseases. MR imaging can provide functional, morphologic, and prognostic value in a single examination by allowing characterization of inflammatory changes from the acute to chronic stages, including edema and the patterns and extent of delayed gadolinium enhancement. We review the heterogeneous and diverse group of cardiac infections based on their site of primary cardiac involvement with emphasis on their cross-sectional imaging manifestations. Online supplemental material is available for this article. (©)RSNA, 2016.

Complications of thoracic endovascular aneurysm repair (TEVAR): A pictorial review.

Thoracic endovascular aneurysm repair (TEVAR) has replaced open surgical repair as the treatment of choice for several aortic conditions. Despite its lower morbidity and mortality, several TEVAR-related complications can occur and some of which may necessitate surgical or endovascular re-intervention. The current article reviews common and rare complications of TEVAR procedure with emphasis on complications identifiable on cross-sectional imaging and potential pitfalls of pre-procedural planning.

Primary pericardial tumors.

Primary pericardial tumors are rare and may be classified as benign or malignant. The most common benign lesions are pericardial cysts and lipomas. Mesothelioma is the most common primary malignant pericardial neoplasm. Other malignant tumors include a wide variety of sarcomas, lymphoma, and primitive neuroectodermal tumor. When present, signs and symptoms are generally nonspecific. Patients often present with dyspnea, chest pain, palpitations, fever, or weight loss. Although the imaging approach usually begins with plain radiography of the chest or transthoracic echocardiography, the value of these imaging modalities is limited. Cross-sectional imaging, on the other hand, plays a key role in the evaluation of these lesions. Computed tomography and magnetic resonance imaging allow further characterization and may, in some cases, provide diagnostic findings. Furthermore, the importance of cross-sectional imaging lies in assessing the exact location of the tumor in relation to neighboring structures. Both benign and malignant tumors may result in compression of vital mediastinal structures. Malignant lesions may also directly invade structures, such as the myocardium and great vessels, and result in metastatic disease. Imaging plays an important role in the detection, characterization, and staging of pericardial tumors; in their treatment planning; and in the posttreatment follow-up of affected patients. The prognosis of patients with benign tumors is good, even in the few cases in which surgical intervention is required. On the other hand, the length of survival for patients with malignant pericardial tumors is, in the majority of cases, dismal.

Pulmonary manifestations of amyloidosis.

Amyloidosis is caused by abnormal protein deposition in various tissues, including the lungs. Pulmonary manifestations of amyloidosis may be categorized by areas of involvement, such as parenchymal, large airway and pleural involvement. We describe four distinct manifestations of amyloidosis involving the lung and review their clinical, radiological and pathological features and summarize the evidence for treatment in each of these presentations. We describe alveolar-septal amyloidosis, cystic amyloid lung disease, endobronchial amyloidosis and pleural amyloidosis.

Imaging patients with cardiac trauma.

In the United States, trauma is the leading cause of death among those who are 1-44 years old, with cardiovascular injuries representing the second most common cause of traumatic death after central nervous system injuries. Evaluation of trauma patients with suspected cardiac injury may be complex and include electrocardiography, measurement of cardiac biomarkers, and imaging examinations. Contrast material-enhanced computed tomography (CT) has become one of the most valuable imaging tools available for evaluating hemodynamically stable patients with suspected cardiac injury. The presence of hemopericardium, with or without cardiac tamponade, is one of the most significant findings of cardiac injury. Other complications that result from blunt cardiac injury, such as pericardial rupture and cardiac herniation, may be readily depicted at multidetector CT. Assessment of patients with cardiac injuries, particularly those with penetrating injuries, is a challenging and time-critical matter, with clinical and imaging findings having complementary roles in the formation of an accurate diagnosis. Patients who are hemodynamically stable, particularly those with penetrating cardiac injuries, also may benefit from a timely imaging examination. In addition to chest radiography, other available modalities such as transthoracic and transesophageal echocardiography, nuclear medicine, and magnetic resonance imaging may play a role in selected cases.

Pneumothorax and pneumomediastinum in COVID-19: A case series.

COVID- 19 has become a major pandemic affecting more than 11 million people worldwide. Common radiological manifestations of COVID-19 include peripheral based ground-glass or consolidative opacities; however, pneumothorax and pneumo-mediastinum are very rare manifestations; even more so within patients not on mechanical ventilation. We present a case series of 5 patients with COVID-19 who either presented with or developed spontaneous pneumothorax or pneumo-mediastinum within the course of hospitalization. With the exception of one patient, all other patients developed pneumothorax as a late manifestation in their illness; more than 10 days after initial symptom onset in COVID-19. From within this case series, all patients who developed spontaneous pneumothorax or pneumo-mediastinum during hospitalization subsequently succumbed to the illness. Spontaneous pneumothorax or pneumo-mediastinum may be an important late manifestation in COVID-19; even in spontaneously breathing patients. This may be related to development of cystic changes within the lung parenchyma. Although the clinical relevance of this finding is unknown; in our series, it portended a worse prognosis in the majority of patients.

It's Not All in Your Head: Thoracic Manifestations of Neurologic Diseases and Disorders.

Myriad conditions may affect both the neurologic system and the thorax, while other diseases primarily affecting the thorax may manifest with neurologic abnormalities. Correlation of signs, symptoms, and imaging findings in the neurological system with those in the thorax can help diagnose certain conditions and/or guide further diagnostic work-up and treatment. We will review and illustrate the imaging appearance of several systemic/neurological diseases with thoracic manifestations as well as discuss conditions in the thorax that can lead to neurologic symptoms.

Aortitis: imaging spectrum of the infectious and inflammatory conditions of the aorta.

Aortitis is a general term that refers to a broad category of infectious or noninfectious conditions in which there is abnormal inflammation of the aortic wall. These inflammatory conditions have different clinical and morphologic features and variable prognoses. The clinical manifestations are usually vague and nonspecific and may include pain, fever, vascular insufficiency, and elevated levels of acute phase reactants, as well as other systemic manifestations. As a result, aortitis is often overlooked during the initial work-up of patients with constitutional symptoms and systemic disorders. A multimodality imaging approach is often required for assessment of both the aortic wall and aortic lumen, as well as for surveillance of disease activity and treatment planning. Noninvasive cross-sectional imaging modalities such as magnetic resonance (MR) imaging, MR angiography, and computed tomographic angiography play a critical role in initial evaluation and further assessment of aortitis. Radiologists should be familiar with the clinical features and imaging findings of the different types of aortitis.

Coronavirus Disease 2019 (COVID-19)-Associated Thromboembolic Disease: A Report of Three Patients With Pulmonary Embolism.

Coagulopathy and thromboembolic disease, including pulmonary embolism (PE), are reported complications of coronavirus disease 2019 (COVID-19). The mechanism is not fully understood. We present three patients with COVID-19 and concurrent PE.

Cross-Sectional Abdominal Imaging Findings in Patients With COVID-19.

Objective We aimed to review and analyze cross-sectional abdominal imaging findings in a cohort of 10 patients who had tested positive for coronavirus disease 2019 (COVID-19). Methods This retrospective study conducted from April 1, 2020, to May 13, 2020, involved two institutions that comprised a central tertiary academic institution and multiple smaller community hospitals. We reviewed and examined cross-sectional imaging studies of patients who tested positive for COVID-19 either during the emergency room (ER) visit or hospital admission. Salient imaging findings and medical records were reviewed. Results A total of 10 COVID-19-positive patients (seven males and three females) of ages ranging from 21-75 years underwent cross-sectional abdominopelvic imaging. Nine of the 10 patients demonstrated typical lung base findings associated with COVID-19 on both CT and MRI. Twelve CT abdominopelvic examinations, one MRI abdomen, and one right upper quadrant ultrasound (RUQ US) were performed, with three patients undergoing two CT scans during the course of hospitalization. Gastric and bowel wall abnormalities were found on 25% (n=3/12) of abdominal CT scans. Acute interstitial pancreatitis and acute cholecystitis were both found on one CT exam. The remaining (n=7/12, 58%) CT studies demonstrated no acute intraabdominal pathology with incidental findings including fatty liver disease, cirrhosis, and splenomegaly. Conclusion A spectrum of abdominal imaging findings ranging from colitis to pancreatitis may be correlated with COVID-19 infection, even though the majority of our patients with gastrointestinal (GI) symptoms did not have identifiable GI pathology on imaging.