Imaging Features of Arrhythmogenic Cardiomyopathies.

Arrhythmogenic cardiomyopathy (ACM) is a genetic disease characterized by replacement of ventricular myocardium with fibrofatty tissue, predisposing the patient to ventricular arrhythmias and/or sudden cardiac death. Most cases of ACM are associated with pathogenic variants in genes that encode desmosomal proteins, an important cell-to-cell adhesion complex present in both the heart and skin tissue. Although ACM was first described as a disease predominantly of the right ventricle, it is now acknowledged that it can also primarily involve the left ventricle or both ventricles. The original right-dominant phenotype is traditionally diagnosed using the 2010 task force criteria, a multifactorial algorithm divided into major and minor criteria consisting of structural criteria based on two-dimensional echocardiographic, cardiac MRI, or right ventricular angiographic findings; tissue characterization based on endomyocardial biopsy results; repolarization and depolarization abnormalities based on electrocardiographic findings; arrhythmic features; and family history. Shortfalls in the task force criteria due to the modern understanding of the disease have led to development of the Padua criteria, which include updated criteria for diagnosis of the right-dominant phenotype and new criteria for diagnosis of the left-predominant and biventricular phenotypes. In addition to incorporating cardiac MRI findings of ventricular dilatation, systolic dysfunction, and regional wall motion abnormalities, the new Padua criteria emphasize late gadolinium enhancement at cardiac MRI as a key feature in diagnosis and imaging-based tissue characterization. Conditions to consider in the differential diagnosis of the right-dominant phenotype include various other causes of right ventricular dilatation such as left-to-right shunts and variants of normal right ventricular anatomy that can be misinterpreted as abnormalities. The left-dominant phenotype can mimic myocarditis at imaging and clinical examination. Additional considerations for the differential diagnosis of ACM, particularly for the left-dominant phenotype, include sarcoidosis and dilated cardiomyopathy. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

A 30-Year-Old Immune Deficient Woman With Persistent Cough and Shortness of Breath.

CASE PRESENTATION: A 30-year-old woman was referred with increasing shortness of breath and cough in the setting of GATA2 deficiency. She initially presented 9 years previously with recurrent episodes of pneumonia and sinusitis. Genetic testing revealed a heterozygous GATA2 mutation (c.988C>T). She has since had multiple infections that have included necrotizing fasciitis of the right thumb, recurrent pilonidal infections (which required 23 procedures), esophageal candidiasis, and human papillomavirus-positive high-grade squamous intraepithelial lesion of the cervix. Serial bone marrow biopsy specimens showed persistent hypocellularity (20% to 60%) with intermittent erythroid atypia and variable detection of trisomy 8, which were concerning for evolving myelodysplastic syndrome. One year before the current admission, she was diagnosed with disseminated Mycobacterium avium complex and was treated with rifabutin, ethambutol, and azithromycin. She was taking voriconazole, acyclovir, and trimethoprim-sulfamethoxazole prophylaxis.

Evaluation with cardiovascular MR imaging of baffles and conduits used in palliation or repair of congenital heart disease.

A wide array of baffles and conduits are used in repair or palliation of congenital heart disease, which is the most common major birth defect, often with complex redirection of blood flow to achieve a more stable physiology. Cardiovascular magnetic resonance (CMR) imaging is an increasingly used modality for noninvasive assessment of anatomy and physiology both before and after surgical intervention, with highly reproducible measurements of ventricular size and function, quantification of valvular insufficiency and flow volumes, and excellent delineation of intracardiac and extracardiac anatomy. The authors review the indications, appearances on CMR images, and potential complications of various cardiovascular baffles and conduits: Mustard and Senning procedures, venoatrial baffles, intraventricular baffles, ventriculoarterial conduits, and baffles and conduits used in functional single-ventricle palliation. CMR imaging offers the most complete evaluation of single-ventricle anatomy and physiology, demonstrating the anatomy of venous pathways and pulmonary arteries and quantifying systemic ventricular size and systolic function, differential pulmonary blood flow, ratio of pulmonary to systemic blood flow, and aortopulmonary collateral flow. Anatomic and physiologic considerations are discussed, and suggested CMR imaging protocols and practical advice for performing and interpreting CMR studies are provided. The diversity and complexity of baffles and conduits complicates performance and interpretation of studies in this population, but a fundamental understanding of the goals of the procedure, postoperative physiology, and potential complications allows targeted imaging and precise reporting of clinically significant findings. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.323115096/-/DC1.

Preprocedural planning with prospectively triggered multidetector row CT angiography prior to bronchial artery embolization in cystic fibrosis patients with massive hemoptysis.

STUDY OBJECTIVES: The aim of this study was to determine if electrocardiographically synchronized, prospectively triggered multidetector row computed tomography (ECG-MDR-CT) angiography of the aorta can accurately predict the location of ectopic bronchial arteries in patients with cystic fibrosis (CF) with massive hemoptysis prior to bronchial artery embolization (BAE). DESIGN AND SETTING: The study was a prospective, observational study from September 1, 2009 to June 30, 2011, conducted at a university hospital with an adult CF center. PATIENTS: The study included adult CF patients with massive hemoptysis. RESULTS: A total of four adult patients (mean [± SD] age = 31.5 ± 7.9 years) with CF and massive hemoptysis underwent ECG-MDR-CT angiography. The location of the bleeding source was predicted in each case based on lung pathology observed on ECG-MDR-CT angiography. All four patients eventually required BAE without the need for conventional aortograms since the locations of the bronchial arteries were determined prior to the procedure. Review of lung pathology and arterial networks from the ECG-MDR-CT angiography data limited the number of selective catheterizations necessary to complete the procedures. BAE resulted in complete resolution of hemoptysis in three patients and successful mitigation of the bleeding in the fourth patient until lung transplantation was performed 1 week later. CONCLUSIONS: ECG-MDR-CT angiography accurately depicted bronchial artery anatomy in CF patients with massive hemoptysis and provided excellent preprocedural planning for BAE. The information provided by ECG-MDR-CT angiography of the aorta prior to conventional angiography decreased the BAE radiation dose and contrast volume and likely reduced table time.

Computer-aided diagnosis of lung nodules on CT scans: ROC study of its effect on radiologists' performance.

RATIONALE AND OBJECTIVES: The aim of this study was to evaluate the effect of computer-aided diagnosis (CAD) on radiologists' estimates of the likelihood of malignancy of lung nodules on computed tomographic (CT) imaging. METHODS AND MATERIALS: A total of 256 lung nodules (124 malignant, 132 benign) were retrospectively collected from the thoracic CT scans of 152 patients. An automated CAD system was developed to characterize and provide malignancy ratings for lung nodules on CT volumetric images. An observer study was conducted using receiver-operating characteristic analysis to evaluate the effect of CAD on radiologists' characterization of lung nodules. Six fellowship-trained thoracic radiologists served as readers. The readers rated the likelihood of malignancy on a scale of 0% to 100% and recommended appropriate action first without CAD and then with CAD. The observer ratings were analyzed using the Dorfman-Berbaum-Metz multireader, multicase method. RESULTS: The CAD system achieved a test area under the receiver-operating characteristic curve (A(z)) of 0.857 +/- 0.023 using the perimeter, two nodule radii measures, two texture features, and two gradient field features. All six radiologists obtained improved performance with CAD. The average A(z) of the radiologists improved significantly (P < .01) from 0.833 (range, 0.817-0.847) to 0.853 (range, 0.834-0.887). CONCLUSION: CAD has the potential to increase radiologists' accuracy in assessing the likelihood of malignancy of lung nodules on CT imaging.

Cross-sectional imaging of primary thoracic sarcomas with histopathologic correlation: a review for the radiologist.

Numerous forms of primary sarcoma can arise from the heart, pericardium, great vessels, lungs, chest wall, and breasts. Magnetic resonance imaging and computed tomography currently play important roles in determining the extent of primary thoracic sarcoma involvement, potential for resectability, and response to therapy. The purpose of this article is to review the various forms of primary sarcoma that may affect the thorax as well as illustrate pertinent cross-sectional radiologic findings with histopathologic correlation.

Effect of CAD on radiologists' detection of lung nodules on thoracic CT scans: analysis of an observer performance study by nodule size.

RATIONALE AND OBJECTIVES: To retrospectively investigate the effect of a computer-aided detection (CAD) system on radiologists' performance for detecting small pulmonary nodules in computed tomography (CT) examinations, with a panel of expert radiologists serving as the reference standard. MATERIALS AND METHODS: Institutional review board approval was obtained. Our dataset contained 52 CT examinations collected by the Lung Image Database Consortium, and 33 from our institution. All CTs were read by multiple expert thoracic radiologists to identify the reference standard for detection. Six other thoracic radiologists read the CT examinations first without and then with CAD. Performance was evaluated using free-response receiver operating characteristics (FROC) and the jackknife FROC analysis methods (JAFROC) for nodules above different diameter thresholds. RESULTS: A total of 241 nodules, ranging in size from 3.0 to 18.6 mm (mean, 5.3 mm) were identified as the reference standard. At diameter thresholds of 3, 4, 5, and 6 mm, the CAD system had a sensitivity of 54%, 64%, 68%, and 76%, respectively, with an average of 5.6 false positives (FPs) per scan. Without CAD, the average figures of merit (FOMs) for the six radiologists, obtained from JAFROC analysis, were 0.661, 0.729, 0.793, and 0.838 for the same nodule diameter thresholds, respectively. With CAD, the corresponding average FOMs improved to 0.705, 0.763, 0.810, and 0.862, respectively. The improvement achieved statistical significance for nodules at the 3 and 4 mm thresholds (P = .002 and .020, respectively), and did not achieve significance at 5 and 6 mm (P = .18 and .13, respectively). At a nodule diameter threshold of 3 mm, the radiologists' average sensitivity and FP rate were 0.56 and 0.67, respectively, without CAD, and 0.67 and 0.78 with CAD. CONCLUSION: CAD improves thoracic radiologists' performance for detecting pulmonary nodules smaller than 5 mm on CT examinations, which are often overlooked by visual inspection alone.

Smoking-related interstitial lung disease: radiologic-clinical-pathologic correlation.

Cigarette smoking is a recognized risk factor for development of interstitial lung disease (ILD). There is strong evidence supporting a causal role for cigarette smoking in development of respiratory bronchiolitis ILD (RB-ILD), desquamative interstitial pneumonitis (DIP), and pulmonary Langerhans cell histiocytosis (PLCH). In addition, former and current smokers may be at increased risk for developing idiopathic pulmonary fibrosis (IPF). The combination of lower lung fibrosis and upper lung emphysema is being increasingly recognized as a distinct clinical entity in smokers. High-resolution computed tomography is sensitive for detection and characterization of ILD and may allow recognition and classification of the smoking-related ILDs (SR-ILDs) into distinct individual entities. However, the clinical, radiologic, and histologic features overlap among the different SR-ILDs, and mixed patterns of disease frequently coexist in the same patient. The overlap is most significant between RB-ILD and DIP. Macrophage accumulation is bronchiolocentric in RB-ILD, producing centrilobular ground-glass opacity, and more diffuse in DIP, producing widespread ground-glass changes. The coexistence of upper lung nodules and cysts in a smoker allows confident diagnosis of PLCH. Final diagnosis of an SR-ILD and identification of the specific entity can be achieved with certainty only after the pulmonologist, radiologist, and pathologist have reviewed all of the clinical, radiologic, and pathologic data.

Case 116: lymphangioleiomyomatosis.

A 49-year-old premenopausal woman presented with acute onset of lower abdominal pain. Physical examination revealed her abdomen was distended and nontender. Her white blood cell count and serum markers for ovarian cancer were normal (alpha-fetoprotein level, 1.6 microg/L; Ca-125 level, 15 U/mL; beta-human chorionic gonadotrophin level < 2 IU/mL). She had no important medical history; in particular, she had no history of malignancy. She denied having any chest symptoms; in particular, she denied experiencing chest pain, cough, or dyspnea. She had stopped smoking at the age of 40 years after having smoked for a total of 20 pack-years. A computed tomographic (CT) examination of the abdomen and pelvis was performed. Helical CT was performed with 150 mL of intravenous contrast material (iohexol, Omnipaque; Amersham Healthcare, Cork, Ireland) and 750 mL of oral contrast material (diatrizoate sodium, Hypaque; Amersham Health, Princeton, NJ). CT sections were 5 mm thick and were acquired from the top of the diaphragm through the ischial tuberosities with a rotation time of 13.5 seconds per rotation and use of a LightSpeed 16 CT scanner (GE Medical Systems, Milwaukee, Wis).

Radiological reasoning: Right atrial mass.

OBJECTIVE: An older man with a history of urothelial cancer presented with an incidental right atrial mass. Cardiac MRI showed a pedunculated right atrial mass that was homogeneous and of intermediate signal intensity on T1- and T2-weighted images. No signal drop-out was seen on fat-suppressed images. The mass did not exhibit enhancement on the first-pass perfusion and delayed contrast-enhanced images. CONCLUSION: A myxoma is the most common benign primary intracavitary cardiac mass. Although the MRI features are not pathognomonic, certain features such as location, presence of a stalk, and noninfiltrating nature may help to distinguish a myxoma from other intracavitary masses such as a thrombus, metastases, and primary cardiac malignancy. The final pathologic diagnosis was a right atrial myxoma.

Imaging of cardiac masses and myocardial disease: self-assessment module.

The educational objectives for this self-assessment module on imaging of cardiac masses and myocardial disease are for the participant to exercise, self-assess, and improve his or her knowledge of imaging and the clinical features of cardiac masses and myocardial disease, with emphasis on CT and MRI.

Thoracic lymph node enlargement in usual interstitial pneumonitis and nonspecific-interstitial pneumonitis: prevalence, correlation with disease activity and temporal evolution.

PURPOSE: To evaluate the prevalence of thoracic lymph node enlargement (LNE) in usual (UIP) and nonspecific (NSIP) interstitial pneumonitis, change in LNE over time, and if LNE is related to disease activity. METHODS AND MATERIALS: High-resolution CT scans (HRCT) in 20 patients each with UIP and NSIP were retrospectively reviewed. Two HRCT scans were reviewed for each patient, at diagnosis and a mean of 1 +/- 0.7 years later. Two thoracic radiologists independently recorded the location and size of thoracic lymph nodes (LNs) > 10-mm in short-axis diameter, using the American Thoracic Society lymph node mapping scheme. HRCT disease severity was scored for ground glass opacity and fibrosis. The number and size of enlarged LN stations were compared with HRCT scores. RESULTS: LNE was found on 44 HRCT examinations (21 baseline prevalence 52.5%, 23 follow-up, prevalence 57.5%), most common in the low right paratracheal (38%) and subcarinal (36%) regions. There was no significant difference in LN size or number of enlarged LN stations between baseline and follow-up CT. LNE prevalence was not different on baseline CT (P = 0.34) follow-up CT (P = 0.11) between UIP and NSIP patients. The mean size of the largest enlarged LN was 1.36 cm (1 to 2.1 cm) at baseline and 1.43 cm (1 to 1.9 cm) on follow-up CT. Mean CT ground glass and fibrosis scores were 1.98 and 1.6 when LNE was present, and 1.34 and 1.03 when absent (P = 0.008 and 0.003, respectively). The number and maximum size of enlarged LNs did not correlate with CT ground glass or fibrosis scores. Five patients who developed LNE between baseline and follow-up CT examinations had a greater increase in CT fibrosis scores than patients whose LNE status did not change (P = 0.004); CT ground glass scores were not significantly different. There was a trend for UIP patients to progress from absence of LNE to presence of LNE (4/20 patients or 20%). CONCLUSIONS: Intrathoracic LNE is common in both UIP and NSIP, and becomes increasingly prevalent in UIP patients over time. LNE is more prevalent with more severe lung disease. An increase in LNE over time is associated with the progression of fibrosis, and should not raise concern for co-existing infection or malignancy, in the absence of other clinical findings that would suggest this.

Postoperative cardiopulmonary thoracic imaging.

An appreciation of the normal postoperative changes and complications following cardiac surgical procedures is essential when interpreting postoperative imaging studies. This article focuses on both the normal postoperative appearances and the imaging of complications following common cardiac surgical procedures. Irrespective of the specific nature of the surgery, certain common complications may occur, either from the surgery itself,the use of cardiac bypass, or the patient's underlying cardiac disorder. Postoperative imaging after specific thoracic cardiovascular surgeries is also discussed.