Faculty Bibliography

Chest CT angiography (CTA) is essential in the diagnosis of acute aortic syndromes. Chest CTA quality can be optimized with attention to technical parameters pertaining to noncontrast imaging, timing of contrast-enhanced imaging, contrast material volume, kilovolt potential, tube-current modulation, and decisions regarding electrocardiographic-gating and ultra-fast imaging, which may affect the accurate diagnosis of acute aortic syndromes. An understanding of methods to apply to address suboptimal image quality is useful, as the accurate identification of acute aortic syndromes is essential for appropriate patient management. Acute aortic syndromes have high morbidity and mortality, particularly when involving the ascending aorta, and include classic aortic dissection, penetrating atherosclerotic ulcer, and acute intramural hematoma. An understanding of the pathogenesis and distinguishing imaging features of acute aortic syndromes and aortic rupture and some less common manifestations is helpful when interpreting imaging examinations. Related entities, such as ulcerated plaque, ulcerlike projections, and intramural blood pools, and mimics, such as vasculitis and aortic thrombus, are important to recognize; knowledge of these is important to avoid interpretive pitfalls. In addition, an awareness of postsurgical aortic changes can be useful when interpreting CTA examinations when patient history is incomplete. The authors review technical considerations when performing CTA, discuss acute aortic syndromes, and highlight diagnostic challenges encountered when interpreting aortic CTA examinations. ^©RSNA, 2021.

We report what appears to be the first case of biopsy-proven nonvalvular endocarditis with biventricular apical infected thrombi. A 47-year-old man presented with hypoxic respiratory failure from a multilobar pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA). Transthoracic echocardiography and cardiac magnetic resonance imaging revealed biventricular apical masses suggestive of nonvalvular endocarditis with infected thrombi. Given concern for ongoing septic embolization to the lungs and brain despite appropriate antimicrobial therapy, the masses were surgically resected. Culture and histopathology confirmed MRSA-positive infected thrombi. In this case report, we highlight the differential diagnosis of apical masses and the role of multimodality imaging.

Background Computed tomography (CT) has become the standard of care for assessment for the suitability for transcatheter mitral valve replacement (TMVR); however, variation in mitral annular measurements across the cardiac cycle has thus far been poorly studied. Because of this, currently TMVR assessment is cumbersome and involves the assessment of multiple phases. We sought to further understand variation in mitral annular dimensions with the cardiac cycle and assess its potential implications for Methods A total of 118 patients presented to the heart valve clinic and underwent CT for possible TMVR assessment and were consecutively studied with multiphase CT. The mitral annulus was measured in 10 phases using 3mensio mitral planning software and several parameters collected including perimeter, area, anterior-posterior (AP) dimension and commissure-commissure (CC) dimension. Results Of the 118 patients screened, 83.9% had predominant MR, 10.2% mixed MS/MR and 5.9% predominant MS. Changes in perimeter, Area, AP and CC dimensions are shown (figure). Comparison of largest and smallest mean measurements for each phase for perimeter, Area, AP and CC dimensions showed a 2.02%, 4.36%, 8.09% and 2.86% variation respectively. Conclusion In contrast to the dynamism of the aortic annulus and neo-LVOT, the mitral annulus does not vary significantly. This may allow limitation of radiation restricting CT acquisitions to mid-systole where the neo-LVOT is smallest. [Figure presented]
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A 51-year-old man with Klippel-Feil syndrome (KFS) and immunodeficiency syndrome, status postintravenous immunoglobulin therapy, presented with shortness of breath. He was found to have severe aortic regurgitation in the setting of a trileaflet aortic valve with thickened leaflets and mild prolapse of the right coronary cusp with left ventricular dilation and borderline left ventricular ejection fraction. Although various cardiac anomalies have been described in KPS, otherwise unexplained severe aortic regurgitation has not been previously reported to the best of our knowledge. The patient underwent an uncomplicated surgical aortic valve replacement with a 25-mm Medtronic Avalus pericardial tissue valve resulting in symptomatic improvement. Intra-operative management and transesophageal echocardiography can be particularly challenging in KFS patients. We describe the first reported case of severe aortic regurgitation in KPS, review the cardiac anomalies associated with the syndrome, and highlight the clinical challenges in intra-operative management of these patients.

Background: Pulmonary embolism (PE) is the third most common acute cardiovascular disease. Computed Tomography Pulmonary Angiography (CTPA) and Ventilation/Perfusion (V/Q) scintigraphy are two imaging modalities commonly used in the evaluation of PE. Dual Energy CT (DECT) is being increasingly utilized in the diagnosis of acute PE. In addition to providing improved contrast resolution and reduction in required volume of intravenous contrast, the generation of pulmonary perfusion maps have proven to be a good surrogate for pulmonary parenchymal perfusion. Color coded perfusion maps are created and fused with the CTPA images providing simultaneous functional assessment of pulmonary perfusion, similar to that seen with perfusion scintigraphy, alongside the high-resolution morphological information from CT. 1. Educational Goals/Teaching Points: Understand the basic principles and physics used in generating pulmonary perfusion maps and how this pertains to accurate interpretation in the diagnosis of acute PE. 2. Become familiar with common artifacts including beam hardening, cardiac and diaphragmatic motion and their appearances in comparison to perfusion defects caused by PE. 3. Interpretating discordant CTPA and perfusion maps: PE on CTPA with negative perfusion maps and no PE seen on CTPA with positive perfusion maps. 4. Common and rare causes of non-thromboembolic perfusion defects including parenchymal and vascular abnormalities. Appreciating which ones are technical and which are secondary to a genuine diminution in perfusion. 5. Differentiating pulmonary infarct from other parenchymal abnormalities with the use of the perfusion map.
Conclusion(s): DECT perfusion mapping is a promising adjunct to conventional CTPA in the evaluation of acute PE, providing simultaneous anatomical and functional information. Correct interpretation requires simultaneous assessment of the lung parenchyma and familiarity with the multiple etiologies and common artifacts that can cause perfusion defects in the absence of PE

Pulmonary embolism is the third most common acute cardiovascular disease. Dual-energy computed tomography perfusion imaging is a promising adjunct in the detection of acute PE providing simultaneous functional assessment of pulmonary perfusion alongside the high-resolution morphological information from computed tomography pulmonary angiography. We review the evidence to date and common causes of perfusion defects including artifacts, parenchymal, and vascular causes, and discuss its potential in furthering our understanding of physiology and pathophysiology in acute pulmonary embolism.

Partial anomalous pulmonary venous return (PAPVR) comprises a group of congenital cardiovascular anomalies associated with pulmonary venous flow directly or indirectly into the right atrium. Scimitar syndrome is a variant of PAPVR in which the right lung is drained by right pulmonary veins connected anomalously to the inferior vena cava. Surgery is the definitive treatment for scimitar syndrome. However, it is not always necessary as many patients are asymptomatic, have small left-to-right shunts, and enjoy a normal life expectancy without surgery. We report multimodality imaging in four adults with scimitar syndrome and the implications for management of this rare syndrome.

This pictorial essay presents cases of congenital coronary artery anomalies, including congenital anomalies of origin, course, and termination. Familiarity with atypical coronary anatomy and clinical presentation may facilitate appropriate diagnosis and management, particularly as cardiac and thoracic computed tomographic utilization increases.

OBJECTIVES: Residual respiratory motion degrades image quality in conventional cardiac cine MRI (CCMRI). We evaluated whether a free-breathing (FB) radial imaging CCMRI sequence with compressed sensing reconstruction [extradimensional (e.g. cardiac and respiratory phases) golden-angle radial sparse parallel, or XD-GRASP] could provide better image quality than a conventional Cartesian breath-held (BH) sequence in an unselected population of patients undergoing clinical CCMRI. MATERIALS AND METHODS: One hundred one patients who underwent BH and FB imaging in a midventricular short-axis plane at a matching location were included. Visual and quantitative image analysis was performed by two blinded experienced readers, using a five-point qualitative scale to score overall image quality and visual signal-to-noise ratio (SNR) grade, with measures of noise and sharpness. End-diastolic and end-systolic left ventricular areas were also measured and compared for both BH and FB images. RESULTS: Image quality was generally better with the BH cines (overall quality grade for BH vs FB images 4 vs 2.9, p < 0.001; noise 0.06 vs 0.08 p < 0.001; SNR grade 4.1 vs 3, p < 0.001), except for sharpness (p = 0.48). There were no significant differences between BH and FB images regarding end-diastolic or end-systolic areas (p = 0.35 and p = 0.12). Eighteen of the 101 patients had poor BH image quality (grade 1 or 2). In this subgroup, the quality of the FB images was better (p = 0.0032), as was the SNR grade (p = 0.003), but there were no significant differences regarding noise and sharpness (p = 0.45 and p = 0.47). CONCLUSION: Although FB XD-GRASP CCMRI was visually inferior to conventional BH CCMRI in general, it provided improved image quality in the subgroup of patients with respiratory-motion-induced artifacts on BH images.

BACKGROUND: Pulmonary artery intimal spindle cell sarcomas are rare and carry with them a poor prognosis and high rate of recurrence. In extremely rare cases, this tumor can infiltrate the pulmonic valve and manifest as adult-onset pulmonic stenosis. CASE PRESENTATION: We report an unusual case of a patient with symptomatic, adult-onset severe pulmonic stenosis who was referred for possible balloon valvuloplasty but was subsequently found to have pulmonary artery intimal sarcoma infiltrating the pulmonary valve leading to progressive exertional dyspnea. CONCLUSION: The presence of adult-onset pulmonic stenosis should prompt the clinician to investigate further as most cases of pulmonic stenosis are congenital in nature and present early in life. Careful diagnostic evaluation in concert with multimodal imaging should take place to arrive at the correct and challenging diagnosis of sarcoma-induced adult-onset severe pulmonic stenosis. Given the poor prognosis and rapid progression of disease, early diagnosis is crucial.