Prachi P. Agarwal

Chest radiographic and CT findings in novel swine-origin influenza A (H1N1) virus (S-OIV) infection

OBJECTIVE This article reviews the chest radiographic and CT findings in patients with presumed/laboratory-confirmed novel swine-origin influenza A (H1N1) virus (S-OIV) infection. MATERIALS AND METHODS Of 222 patients with novel S-OIV (H1N1) infection seen from May 2009 to July 2009, 66 patients (30%) who underwent chest radiographs formed the study population. Group 1 patients (n = 14) required ICU admission and advanced mechanical ventilation, and group 2 (n = 52) did not. The initial radiographs were evaluated for the pattern (consolidation, ground-glass, nodules, and reticulation), distribution, and extent of abnormality. Chest CT scans (n = 15) were reviewed for the same findings and for pulmonary embolism (PE) when performed using IV contrast medium. RESULTS Group 1 patients were predominantly male with a higher mean age (43.5 years versus 22.1 years in group 2; p < 0.001). The initial radiograph was abnormal in 28 of 66 (42%) subjects. The predominant radiographic finding was patchy consolidation (14/28; 50%) most commonly in the lower (20/28; 71%) and central lung zones (20/28; 71%). All group 1 patients had abnormal initial radiographs; extensive disease involving > or = 3 lung zones was seen in 93% (13/14) versus 9.6% (5/52) in group 2 (p < 0.001). No group 2 patients had > 20% overall lung involvement on initial radiographs compared with 93% of group 1 patients (13/14). PEs were seen on CT in 5/14 (36%) of group 1 patients. CONCLUSION Chest radiographs are normal in more than half of patients with S-OIV (H1N1) and progress to bilateral extensive air-space disease in severely ill patients, who are at a high risk for PE.

Multidetector CT of thoracic aortic aneurysms

Thoracic aortic aneurysms (TAAs) can be broadly divided into true aneurysms and false aneurysms (pseudoaneurysms). True aneurysms contain all three layers of the aortic wall (intima, media, and adventitia), whereas false aneurysms have fewer than three layers and are contained by the adventitia or periadventitial tissues. Multidetector computed tomographic (CT) angiography allows the comprehensive evaluation of TAAs in terms of morphologic features and extent, presence of thrombus, relationship to adjacent structures and branches, and signs of impending or acute rupture, and is routinely used in this setting. Knowledge of the causes, significance, imaging appearances, and potential complications of both common and uncommon aortic aneurysms, as well as of the normal postoperative appearance of the thoracic aorta, is essential for prompt and accurate diagnosis. Supplemental material available at http://radiographics.rsnajnls.org/cgi/content/full/29/2/537/DC1.

Aortic Valve Area on 64-MDCT Correlates with Transesophageal Echocardiography in Aortic Stenosis

OBJECTIVE The purpose of our study was to compare aortic valve area and calcification between CT and echocardiography. MATERIALS AND METHODS We performed retrospective evaluation of 80 consecutive patients with aortic stenosis (AS) who underwent ECG-gated 64-MDCT and transesophageal echocardiography (TEE). Valve planimetry was feasible in 80 patients with CT and in 63 patients with TEE; valve area by transthoracic echocardiography was available in 46 patients. Valve calcification grade on CT was compared with TEE. One cardiologist (echocardiography) and two radiologists (CT) independently and blindly reviewed the studies. Pearsons correlations, Spearmans rank correlations, paired Students t tests, and weighted kappa tests were used. RESULTS The median valve area on TEE was 0.7 +/- 0.9 cm(2). There was excellent correlation (n = 80; r = 0.91, p < 0.001) and no difference (0.06 +/- 0.26 cm(2), p = 0.06) between CT readers. There was strong correlation (n = 63; r = 0.84, p < 0.001) and no difference (-0.06 +/- 0.48 cm(2), p = 0.33) in valve area between CT and TEE, with a strong correlation (n = 46; r = 0.83, p < 0.001) and small overestimation (0.17 +/- 0.33 cm(2), p < 0.001) in valve area with CT versus transthoracic echocardiography. The sensitivity and specificity of CT to detect severe aortic stenosis compared with TEE were 92.1% (35/38) and 89.5% (17/19), respectively. Calcification grade had fair agreement between CT readers and TEE (kappa = 0.34 and 0.37, respectively). CONCLUSION Aortic valve area on CT strongly correlates with echocardiography and has excellent sensitivity and specificity to detect severe stenosis. Valve calcification has fair agreement between studies. Valve area and calcification should be reported on CT angiography in patients with AS.

Evaluation of Mechanical Heart Valve Size and Function With ECG-Gated 64-MDCT

OBJECTIVE The purpose of our study was to determine whether CT can accurately evaluate mechanical heart valve size and function. MATERIALS AND METHODS Sixty-two patients with mechanical valves (37 single-disc, 27 bileaflet; 59 aortic, 5 mitral) were evaluated with ECG-gated 64-MDCT and transthoracic echocardiography; a subset of 10 patients underwent cinefluoroscopy. Two readers independently interpreted each study. RESULTS The mean age of the patients was 46.4 +/- 14.4 years; 50 were men and 12 were women. There was excellent correlation, and differences between CT readers were absent to small in measuring the opening angle (r = 0.96, p < 0.001; 76.7 +/- 9.0 degrees vs 76.8 +/- 9.6 degrees , p = 0.73), annulus diameter (r = 0.96, p < 0.001; 25.9 +/- 3.3 vs 25.9 +/- 3.2 mm, p = 0.62), and geometric orifice area (r = 0.98, p < 0.001; 3.8 +/- 0.9 vs 3.6 +/- 0.8 cm(2), p < 0.001). There was strong correlation without difference in opening angle between CT and cinefluoroscopy (r = 0.77, p < 0.001; 79.2 degrees +/- 9.8 degrees vs 77.2 degrees +/- 15.5 degrees , p = 0.45). Compared with manufacturer specifications, CT reported opening angles that were smaller for single-disc valves (n = 36, 67.4 degrees +/- 5.7 degrees vs 75 degrees , p < 0.001) and similar for bileaflet valves (n = 42 for 21 valves, 83.8 degrees +/- 3.9 degrees vs 85 degrees , p = 0.05), valves, with small underestimation with CT versus specifications in annulus diameter (n = 41; r = 0.75, p < 0.001; 26.4 +/- 3.0 vs 27.5 +/- 3.3 mm, p = 0.003), and geometric orifice area (n = 35; r = 0.90, p < 0.001; 3.7 +/- 0.7 vs 3.8 +/- 0.8 cm(2), p = 0.04). Each disc closed fully on CT; none had more than mild regurgitation on echocardiography. CONCLUSION CT can measure the size and function of mechanical valves with high interobserver agreement and results similar to specifications. The opening angle with CT strongly correlates with cinefluoroscopy. CT is promising for the assessment of mechanical valves.

Relation of Right Ventricular Dilation, Age of Repair, and Restrictive Right Ventricular Physiology With Patient-Reported Quality of Life in Adolescents and Adults With Repaired Tetralogy of Fallot

The present study aimed to determine the predictors of patient-reported quality of life and restrictive right ventricular (RV) physiology in adolescents and adults with repaired tetralogy of Fallot. A total of 62 patients (median age 28.5 years, range 14 to 69) undergoing cardiovascular magnetic resonance imaging completed the Short Form 36-item questionnaire, version 2, a validated quality of life assessment. RV inflow curves were generated from the sum of tricuspid inflow and pulmonary insufficiency. The patient-reported quality of life was comparable to population norms. Patients repaired after 1 year of age showed a strong trend toward a greater likelihood of physical component summary age-adjusted z-score ≤-1 (odds ratio 7.50, 95% confidence interval 0.90 to 62.3, p = 0.06). Patients with a RV ejection fraction of <45% reported decreased physical component summary (p = 0.02) and physical functioning (p = 0.02) scores. The RV end-diastolic volume, pulmonary regurgitation, and diastolic indexes did not predict the quality of life. The indexed RV end-diastolic volume was related to diastolic abnormalities, correlating with a greater peak early filling rate (r = 0.71, p <0.0001), ratio of peak early to atrial filling rates (r = 0.45, p = 0.006), and showing a strong trend with the end-diastolic forward flow in the pulmonary trunk (odds ratio 2.67 for moderate dilation and 3.50 for severe dilation, p = 0.06). Patients who underwent repair before 1 year old were more likely to have end-diastolic forward flow (15 of 17 vs 25 of 42, p = 0.03). In conclusion, the RV ejection fraction and age of repair were the best predictors of quality of life in this population, in whom end-diastolic forward flow and associated diastolic parameters appeared to reflect an overdistended ventricle, which might suggest a role for early pulmonary valve replacement.

Thoracic CT Findings in Birt-Hogg-Dubé Syndrome

OBJECTIVE Birt-Hogg-Dubé syndrome manifests in the thorax as lung cysts. The purpose of this article is to describe the CT characteristics of cysts in patients with Birt-Hogg-Dubé syndrome and to note other thoracic findings. MATERIALS AND METHODS The thoracic CT examinations of 17 patients with Birt-Hogg-Dubé syndrome were reviewed retrospectively for the presence, anatomic distribution (upper lung predominant, lower lung predominant, or diffuse), extent (size, number), and morphology (shape, wall thickness) of cysts. Any additional thoracic findings were also noted. RESULTS The study population consisted of 13 women (76%) and four men (24%) with a mean age of 50.2 ±15.2 years. Two patients (12%) had normal findings on CT. Fifteen patients had cystic lung disease, all of whom had more than one cyst. Most patients had bilateral (13/15, 87%) and lower lung-predominant cysts (13/15, 87%). The cysts varied in size from 0.2 to 7.8 cm. The largest cysts were located in the lower lobes of 14 of 15 patients (93%). Of the nine patients with large cysts, most had at least one multiseptated cyst (7/9, 78%). Five of 15 patients (33%) had more than 20 cysts. Cyst shape varied among the 15 patients and also within individual patients (10/15, 67%) ranging from round to oval, lentiform, and multiseptated. Cysts showed no central or peripheral predominance. CONCLUSION Discrete thin-walled cysts in patients with Birt-Hogg-Dubé syndrome are more numerous and larger in the lower lobes and vary in size and shape. Large lung cysts are frequently multiseptated. These features may aid in differentiating Birt-Hogg-Dubé syndrome from other more common cystic lung diseases.

Effect of Moderate-Intensity Exercise Training on Peak Oxygen Consumption in Patients With Hypertrophic Cardiomyopathy: A Randomized Clinical Trial

Importance Formulating exercise recommendations for patients with hypertrophic cardiomyopathy is challenging because of concern about triggering ventricular arrhythmias and because a clinical benefit has not been previously established in this population. Objective To determine whether moderate-intensity exercise training improves exercise capacity in adults with hypertrophic cardiomyopathy. Design, Setting, and Participants A randomized clinical trial involving 136 patients with hypertrophic cardiomyopathy was conducted between April 2010 and October 2015 at 2 academic medical centers in the United States (University of Michigan Health System and Stanford University Medical Center). Date of last follow-up was November 2016. Interventions Participants were randomly assigned to 16 weeks of moderate-intensity exercise training (n = 67) or usual activity (n = 69). Main Outcomes and Measures The primary outcome measure was change in peak oxygen consumption from baseline to 16 weeks. Results Among the 136 randomized participants (mean age, 50.4 [SD, 13.3] years; 42% women), 113 (83%) completed the study. At 16 weeks, the change in mean peak oxygen consumption was +1.35 (95% CI, 0.50 to 2.21) mL/kg/min among participants in the exercise training group and +0.08 (95% CI, −0.62 to 0.79) mL/kg/min among participants in the usual-activity group (between-group difference, 1.27 [95% CI, 0.17 to 2.37]; P = .02). There were no occurrences of sustained ventricular arrhythmia, sudden cardiac arrest, appropriate defibrillator shock, or death in either group. Conclusions and Relevance In this preliminary study involving patients with hypertrophic cardiomyopathy, moderate-intensity exercise compared with usual activity resulted in a statistically significant but small increase in exercise capacity at 16 weeks. Further research is needed to understand the clinical importance of this finding in patients with hypertrophic cardiomyopathy, as well as the long-term safety of exercise at moderate and higher levels of intensity. Trial Registration clinicaltrials.gov Identifier: NCT01127061

Dual left anterior descending coronary artery: CT findings.

OBJECTIVE Dual left anterior descending coronary artery (LAD) is a rare congenital anomaly with four subtypes. This anomaly has been described in the angiographic literature, but with the increasing use of coronary CT, it becomes imperative for CT interpreters to be aware of this entity, its implications, and the cross-sectional findings. We report the ECG-gated 64-MDCT coronary angiographic findings on two types of dual LAD (types 1 and 4). The imaging findings of the other types of dual LAD also are discussed. CONCLUSION It is important for CT interpreters to be aware of and recognize dual LAD at coronary CT. Because of inability to visualize the additional vessel, especially when the long LAD originates from the right coronary sinus, the variant anatomic features can be misinterpreted at routine coronary angiography for mid-LAD occlusion. Identification of an additional LAD can be important for diagnosis and therapeutic planning.

Common and uncommon vascular rings and slings: a multi-modality review

Vascular rings and pulmonary slings are congenital anomalies of the aortic arch/great vessels and pulmonary arteries, respectively, that commonly present early during infancy and childhood with respiratory and/or feeding difficulties. The diagnosis of these conditions frequently utilizes a multi-modality radiological approach, commonly utilizing some combination of radiography, esophagography, CT angiography and MR angiography. The purpose of this pictorial review is to illustrate the radiological findings of common and uncommon vascular rings and pulmonary slings in children using a state-of-the-art multi-modality imaging approach.

Clinical significance of late gadolinium enhancement in patients<20 years of age with hypertrophic cardiomyopathy.

Late gadolinium enhancement (LGE) on cardiovascular magnetic resonance imaging is associated with adverse events in adults with hypertrophic cardiomyopathy (HC). However, limited data exist on the extent and clinical significance of LGE in the pediatric population. In 30 patients (aged 14.1±3.2 years) with clinically diagnosed HC who underwent cardiovascular magnetic resonance imaging from 2007 to 2012, segments with hypertrophy and LGE were identified by 2 experienced readers blinded to outcome. Radial, circumferential, and longitudinal strains were evaluated using feature tracking software. The composite outcome was defined as cardiac death, nonsustained ventricular tachycardia, ventricular fibrillation, or appropriate implantable cardioverter-defibrillator discharge. LGE was present in 17 of 30 patients (57%), all in a midmyocardial pattern, with median 3 segments per patient (interquartile range [IQR] 2 to 5). No LGE was detected in patients without phenotypic hypertrophy. Segments with LGE had decreased radial (basal segments 20.7% vs 70.9%, p=0.01), circumferential (basal segments -23.2% vs -29.3%, p=0.04), and longitudinal strains (basal segments -13.8% vs -20.9%, p=0.04). After median follow-up of 26.9 months (IQR 7.5 to 34.3), 7 patients who had an adverse outcome (5 ventricular tachycardia, 1 appropriate implantable cardioverter-defibrillator discharge, and 1 death) had more segments of LGE (median 4, IQR 2 to 7 vs 0, IQR 0 to 2, p=0.01). One patient without LGE had ventricular tachycardia on exercise test. In conclusion, LGE occurs in a similar pattern in pediatric patients with HC as in adults, associated with hypertrophy, decreased myocardial strain, and adverse clinical outcomes. Further longitudinal studies are necessary to evaluate the rate of development of LGE and relation to outcomes in a larger cohort.