Simultaneous Presentation of Swimming-Induced Pulmonary Edema in a Set of Monozygotic Twin Elite Maritime Warfare Candidates: A Novel Case Report.

Swimming-induced pulmonary edema (SIPE) is an incompletely understood condition that is often seen in U.S. special operations candidates participating in maritime qualification training courses. We present a case of two monozygotic twins with the simultaneous onset of acute respiratory distress during a crucible event of a maritime assessment and selection course. Subsequent pulmonary ultrasonography in both candidates showed wedge-shaped hyperechoic lines (B-lines) extending from the pleural interface into the interstitium. Chest radiography of both candidates revealed bilateral asymmetric hazy opacities consistent with SIPE. Both candidates recovered with supportive measures but were medically removed from training. Given the near-identical exposures of the candidates to the same ambient and water temperatures, duration of water submersion, magnitude of physical stressors, and viral colonization, this case study suggests that there may be underlying genetic factors, in addition to environmental factors, that predispose individuals to developing SIPE. Further benchtop and clinical research must be performed to identify potential genetic polymorphisms that contribute to the development of SIPE and to investigate safe interventions that address the underlying etiologies of SIPE pathophysiology.

Pulmonary Barotrauma in a BUD/S Candidate Following Shallow Dives Using the MK 25 Rebreather.

Pulmonary barotrauma of ascent is a well-recognized risk of compressed air diving in the civilian and military diving communities. Chest imaging is a beneficial adjunct to clinical evaluation in screening select individuals for fitness to dive, evaluating dive-related injuries, and safely returning individuals to diving duty. We present a case of a 26-year-old male U.S. Navy Ensign and Basic Underwater Demolition/SEAL (BUD/S) candidate who experienced pulmonary barotrauma following two shallow dives to a maximum depth of 18 feet of seawater using the MK-25 100% oxygen rebreather. A chest radiograph showed a left upper lobe peripheral wedge-shaped opacity abutting the pleural surface. A subsequent computerized tomography (CT) scan of the chest showed multifocal areas of peripheral pulmonary hemorrhage associated with small pneumatoceles. Two months after the diving injury, chest CT showed resolution of the pulmonary hemorrhage and pneumatoceles. Diving-related pulmonary barotrauma occurs most often secondary to breath-holding on ascent by inexperienced divers and is one of the most common diving injuries seen in BUD/S candidates. The risk of pulmonary barotrauma may be decreased through adequate training and thorough medical screening to include assessing for symptoms of infection before every dive. In cases of acute pulmonary barotrauma, chest radiographs may be used to screen for thoracic injury. Chest CT with inspiratory and expiratory sequences should be used to screen dive candidates on a case-by-case basis and to evaluate lung injury and predisposing pulmonary conditions following pulmonary barotrauma.

Incidence of Respiratory Pathogens in Naval Special Warfare Sea, Air, and Land Team Candidates With Swimming-Induced Pulmonary Edema.

BACKGROUND: Swimming-induced pulmonary edema (SIPE) is a respiratory condition frequently seen among Naval Special Warfare (NSW) trainees. The incidence of positive respiratory panel (RP) findings in trainees with a diagnosis of SIPE currently is unknown. RESEARCH QUESTION: Does a significant difference exist in the incidence of respiratory pathogens in nasopharyngeal samples of NSW candidates with SIPE and a control group? STUDY DESIGN AND METHODS: Retrospective analysis of clinical information from NSW Sea, Air, and Land (SEAL) team candidates with a diagnosis of SIPE over a 12-month period. Candidates who demonstrated the common signs and symptoms of SIPE underwent a nasopharyngeal swab and RP test for common respiratory pathogens. SIPE diagnoses were supported by two-view chest radiography. RP tests were obtained for a selected control group of first-phase trainees without SIPE. RESULTS: Forty-five of 1,048 SEAL team candidates received a diagnosis of SIPE (4.3%). Five had superimposed pneumonia. Thirty-six of 45 showed positive results for at least one microorganism on the RP (80%). In the study group, human rhinovirus/enterovirus (RV/EV) was the most frequently detected organism (37.8%), followed by coronavirus OC43 (17.8%), and parainfluenza virus type 3 (17.8%). Sixteen of 68 candidates from the control group showed positive RP (24%) findings. Patients with SIPE and positive RP results reported dyspnea (94%), pink frothy sputum (44%), and hemoptysis (36%) more frequently than the control participants with positive RP results. Those who reported respiratory infection symptoms in both the study and control groups showed higher incidences of positive RP results (P = .046). INTERPRETATION: We observed that 80% of trainees with a diagnosis of SIPE showed positive results on a point-of-care RP. This positivity rate was significantly higher than that of RP test results from the control cohort. These findings suggest an association between colonization with a respiratory pathogen and the development of SIPE in NSW candidates.

Dual-Energy, Dual-Exposure PA and Lateral Chest Radiograph: Not Your Father's Chest X-Ray.

In the last two decades, our military and federal health care facilities have transitioned from traditional X-rays exposing film screen systems, developed much like photographic film, to an entirely digital detection system that affords computer processing of images and digital image and report distribution. While health care providers are well aware of the practicality of these advancements, they may not be aware of the improved diagnostic capabilities afforded by these new methods. In this report, we outline how application of physical principles of X-rays, with digital detectors and computer data manipulation, can present images demonstrating chest and heart diseases that were previously not readily visible by traditional film screen systems. More recently, dual-energy, dual-exposure systems have been implemented. This commentary is to educate the medical community so that they may better understand not only the written report but the information on the images being provided, along with potential pitfalls to avoid. Specifically, we demonstrate improved detection of pulmonary nodules and coronary atherosclerosis with the dual-energy technique.

Opportunistic Detection of Coronary Calcium on Dual-Energy Lateral Chest Radiograph.

ABSTRACT: Heart disease remains the leading cause of death among men and women in the world. The majority of cardiac morbidity worldwide is secondary to atherosclerotic coronary disease. In this article, we discuss our experience using dual exposure, dual-energy lateral chest x-ray (CXR) technique to detect coronary calcium. Similar to other reports demonstrating opportunistic detection on imaging studies, here we demonstrate the added value of detection of coronary calcium on the lateral CXR. This technique reinforces the importance of "knowing where to look" and to recognize the appearance of coronary calcium wherein subtle cardiac motion can be a useful artifact in the accurate detection of coronary calcium. In addition, we discuss correlating coronary calcium burden with age, elaborate on the physics behind coronary calcium detection, and how best to optimize imaging technique. Lastly, we show other uses of dual-energy lateral CXR technique to illustrate where using material decomposition and subtle motion can better define contours in the mediastinum and lung.

Multimodality Imaging Assessment of Anomalous Aortic Origin of the Left Main Coronary Artery Presenting With Syncope and Non-ST Elevation Myocardial Infarction.

Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital abnormality associated with myocardial ischemia and sudden cardiac death. We present a case of a 20 year old previously healthy male presenting with exertional syncope and non-ST elevation myocardial infarction. Coronary computed tomography angiography showed an anomalous left main coronary artery arising from the right coronary cusp with a slit-like appearance, acute angle origin, intramural course, and a subsequent inter-arterial course between the main pulmonary artery and the proximal aorta. Cardiac magnetic resonance imaging demonstrated myocardial infarction in the distribution of the left main coronary artery. The patient underwent successful surgical correction with unroofing of the left main coronary artery. He has had no syncopal episodes or recurrence of chest pain and returned to full duty status in the United States Marine Corps. This case report demonstrates the evaluation and management of a patient with AAOCA.

Incidence and Impact of Swimming-Induced Pulmonary Edema on Navy SEAL Candidates.

BACKGROUND: Respiratory complications such as swimming-induced pulmonary edema (SIPE) are a common feature of United States Navy Special Warfare (NSW) training. RESEARCH QUESTION: This study was designed to evaluate the incidence and clinical features of SIPE seen in this population. STUDY DESIGN AND METHODS: A prospective, observational review of all NSW candidates over a 15-month period was designed. Baseline height, weight, and ECG data were obtained. Candidates with respiratory issues were evaluated with a two-view chest radiograph and ECG while symptomatic and were closely followed up. The chest radiograph and clinical data were then independently reviewed. RESULTS: A total of 2,117 NSW candidates participated in training during the study period, with 106 cases of SIPE identified (5.0%). Ten additional cases of SIPE were repeat episodes in candidates already diagnosed. Forty-four cases of pneumonia were identified (no repeat cases). The majority had cough (90.4%), frothy-pink sputum (35.6%), and hemoptysis (23.7%). Overall, 80.1% of candidates had an oxygen saturation ≥ 90%. Physical examination findings were variable: crackles (50%), wheezing (36%), and rhonchi (19%). Several had more than one feature; 23% presented with a normal examination. Radiologic findings in patients with SIPE most commonly revealed an interstitial pattern with perifissural thickening, larger average azygos vein diameter, larger average heart size, and normal lung height. ECG findings were not significantly different from baseline. Height and weight were not significantly different between the groups. Lower water temperatures were suggestive of increased SIPE incidence, but this was not a statistically significant trend. INTERPRETATION: The burden of SIPE in NSW training was greater than anticipated. Clinical symptoms and physical examination assisted by imaging were able to differentiate SIPE from pneumonia. ECG was not a useful diagnostic or screening tool, and height and weight did not affect risk of SIPE. TRIAL REGISTRY: Institutional Review Board registration at Naval Medical Center, San Diego, California; Registration No.: NMCSD.2017.0020.

Lung Cancer Screening at a Military Treatment Facility: A Retrospective Review.

INTRODUCTION: Lung cancer is the leading cause of cancer death among men and women, accounting for more fatalities than colon, breast, and prostate cancers combined. Smoking causes about 85% of all lung cancers in the United States and is the single greatest risk factor. In 2013, the US Preventive Services Task Force (USPSTF) published initial guidelines for low-dose computed tomography lung cancer screening (LCS) among patients 55-80 years old, with a 30-pack-year history, who are current smokers or who quit within the previous 15 years. Smoking prevalence is higher among military personnel compared to the civilian population, demonstrating a need for vigilant screening. MATERIALS AND METHODS: A retrospective review of Naval Medical Center San Diego's (NMCSD) LCS data was conducted to examine screening numbers, lung cancer rates, and initial analysis of screening results. Patients were referred for screening if they met the USPSTF criteria. Between September 2013 and September 2018, 962 patients underwent LCS. A total of 1758 examinations were performed, including follow-up and annual surveillance examinations. The American College of Radiology's Lung CT Screening Reporting and Data System (Lung-RADS) was used to classify lung nodules' risk for malignancy. RESULTS: On this initial analysis, 42 enrolled patients received the diagnosis of lung cancer detected by screening. The initial calculated lung cancer rate is 4.4% (42/962) over the 5-year reporting period. The lung cancer rate among those patients with a Lung-RADS score of 3 or 4 was 31% (42/135). Thirty-seven patients were classified as having non-small cell lung cancer (NSCLC), while five were classified as having small cell lung cancer. Of the 37 NSCLC patients, 76% (28/37) were diagnosed at stage I and II, 11% (4/37) were diagnosed at stage III, and 13% (5/37) were diagnosed at stage IV. The total number of years a person smoked was a significant risk factor (P = 0.004), but not pack-years a person smoked (P = 0.052). CONCLUSIONS: These preliminary results demonstrate the success of a Military Treatment Facility (MTF)-based LCS Program in the detection of early stage lung cancer. Earlier stage detection may result in better health outcomes for affected patients. In the population studied, duration of smoking proved to be more significant than pack-years in predicting lung cancer risk. These results validate the newly dedicated resources and continued efforts to strengthen the LCS program at NMCSD and across MTFs.

Parathyroid Computed Tomography Angiography: Early Experience with a Novel Imaging Technique in Primary Hyperparathyroidism.

OBJECTIVES: To describe parathyroid computed tomography angiography (PCTA), determine its accuracy, and, as a secondary objective, calculate its mean radiation dosimetry. STUDY DESIGN: Retrospective chart review of patients who underwent parathyroidectomy for primary hyperparathyroidism from 2007 to 2015. SETTING: Single-center tertiary care academic military hospital. SUBJECTS AND METHODS: PCTA is a 2-phase computed tomography imaging technique that uses individualized timing of contrast infusion and novel patient positioning to accurately identify parathyroid adenomas. Consecutive patients who underwent parathyroidectomy for primary hyperparathyroidism from 2007 to 2015 were reviewed; 55% of patients were women. The mean age was 50.9 years (range, 26-68 years). Sensitivity and specificity were calculated as well as mean radiation dosimetry and timing of contrast. RESULTS: A total of 108 procedures were performed during the study period. Twenty-one patients undergoing 22 PCTAs after prior sestamibi scans were nonlocalizing or equivocal. In this group, there were 15 true-positive, 3 false-positive, 4 true-negative, and 0 false-negative PCTAs. This represents a sensitivity of 100% (95% CI, 74.7%-100%) and a specificity of 57% (95% CI, 20%-88%). The mean calculated radiation dose was 5.15 mSv. In the most recent studies, a mean dose of 4.1 mSv was calculated. The ideal time of image acquisition contrast administration varied from 20 to 30 seconds after contrast infusion. CONCLUSIONS: PCTA is a new technique in anatomic imaging for hyperparathyroidism. In a single-center, single-radiologist retrospective study, it demonstrates excellent accuracy for patients with parathyroid adenomas that are otherwise difficult to localize preoperatively. Preliminary experience suggests that its use may be indicated as a primary imaging modality in the future.

Development and Early Experience of the First Joint Military Health System-Veterans Affairs Transcatheter Aortic Valve Replacement Program.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is a minimally invasive cardiac surgical procedure that has revolutionized the treatment of aortic stenosis. This is the most common valvular heart condition in developed countries, affecting 3.4% of those ages 75 and above. Because there is no medical therapy that can arrest progression of the disease, valve replacement forms the cornerstone of therapy. METHODS: Naval Medical Center San Diego and the VA San Diego Healthcare System have developed a unique collaborative TAVR program-a first in the Department of Defense-to offer this revolutionary procedure to their beneficiaries. Herein, we review development of the program and outcome for patients referred during the first 9 months. FINDINGS: Development of the program was a multiyear process made successful because of administrative support, facility upgrades, and collaboration within the crossfacility and multispecialty heart valve team. In the first 9 months, 29 patients were referred for evaluation. Twenty-two (average age 80 years) underwent TAVR, whereas others were deemed nonoperable or were pending disposition at the time of this report. Patients who underwent TAVR had a predicted risk of procedural mortality from surgical aortic valve replacement of 7.7%, similar to other trials and registry studies. After mean follow-up of 5.6 months (range 30-355 days), zero deaths were recorded in the patients who underwent TAVR. Compared to other nonfederal local institutions, the program also realized a cost savings of approximately 17%, or nearly $10,000, per patient. DISCUSSION: In the first 9 months, results were positive and consistent with expectations from national and international registries. Our hope is that this program may serve as an example for other federal facilities looking to start their own combined programs to improve health care quality and patient experience while simultaneously achieving considerable cost containment within a constrained national health care budget.

CT dose reduction using prospectively triggered or fast-pitch spiral technique employed in cardiothoracic imaging (the CT dose study).

OBJECTIVES: To establish current radiation dose levels with contemporary scanners capable of prospectively triggered or high-pitch spiral scan modes to previous generation scanners among patients evaluated for coronary artery disease, pulmonary embolism, aortic disease, and "triple rule out" in a large population of patients at multiple centers. BACKGROUND: Previous small-scale studies with carefully controlled scan protocols report that CT scanners that facilitate prospectively triggered scanning and provide high-pitch spiral CT scan modes drastically lower radiation doses. However, diagnostic reference levels should be selected by medical bodies on the basis of large surveys of representative sites and reviewed at appropriate time intervals. METHODS: Scan data including dose and image quality parameters were collected retrospectively from 64 slice scanners (control) and prospectively after sites installed 128-slice dual-source scanners with high-pitch capability (study). Protocol selection was purposely not specified to survey "real world" results. Blinded quantitative image analysis was performed on every fifth scan. RESULTS: From April 2011 to March 2012, 2085 patients at 9 sites completed the study: 1051 coronary artery disease (509 control, 542 study), 528 pulmonary embolism (267 control, 261 study), 419 aortic disease (268 control, 151 study), and 87 triple rule out (53 control, 34 study). There was a significant reduction in median dose-length product (DLP) from 669 mGy ∙ cm (interquartile range [IQR]: 419-1026 mGy ∙ cm) in the control group to 260 mGy ∙ cm (IQR: 159-441 mGy ∙ cm) in the study group, a reduction by 61% (P < .0001) and was lower in all categories. No significant differences were noted in image quality. CONCLUSION: Use of advanced scanners facilitating prospectively triggered or high-pitch spiral scan modes results in marked dose reduction across a variety of cardiovascular studies, with no compromise in image quality. These findings may contribute to new target dose recommendations in societal guidelines.

Diagnosis of right ventricular cardiac sarcoidosis with cardiac magnetic resonance in a patient presenting with ventricular tachycardia.

Sarcoidosis patients often have myocardial involvement, however, very few have clinically significant cardiac disease and ventricular tachycardia as the initial presentation is exceedingly rare. We report the case of a middle-aged male with symptomatic but clinically stable ventricular tachycardia. Chest radiograph, computed tomography, and positron emission tomography demonstrated pulmonary and mediastinal abnormalities but no definitive etiology for his arrhythmia. Transthoracic echocardiogram revealed the nonspecific cardiac abnormalities of right ventricular dilation and septal flattening. Cardiac magnetic resonance demonstrated delayed enhancement and akinesia of the right ventricular free and inferior walls--virtually diagnostic of an infiltrative myocardial disease. The diagnosis was then verified with transbronchial biopsy showing noncaseating granulomas consistent with sarcoidosis. In conclusion, this case illustrates an unusual presentation of sarcoidosis and demonstrates how the diagnosis can be made using cardiac magnetic resonance alongside transbronchial biopsy.

Bronchial carcinoid imaged with cardiac gated, 128-slice, dual-source, flash CT scanner to direct operative management.

Carcinoid is a rare lung cancer that typically presents with a relatively indolent clinical behavior. We present the case of a 32-year-old male with progressive respiratory symptoms, which resulted in the diagnosis of typical bronchial carcinoid. This case shows a novel imaging technique for staging a bronchial carcinoid for determination of optimal management. This case also shows the multidisciplinary approach required for management of patients with carcinoid tumors.

Cardiac gated computed tomography used to confirm iatrogenic aortic valve leaflet perforation after mitral valve replacement.

Aortic insufficiency from iatrogenic valve perforation from nonaortic valve operations is rarely reported despite the prevalence of these procedures. Rapid diagnosis of these defects is essential to prevent deterioration of cardiac function. In this paper, we describe a young man who reported to our institution after two open cardiac surgeries with new aortic regurgitation found to be due to an iatrogenic perforation of his noncoronary aortic valve cusp. This defect was not appreciated by previous intraoperative transesophageal echocardiography and was inadequately visualized on follow-up transthoracic and transesophageal echocardiograms. In contrast, cardiac gated computed tomography clearly visualized the defect and its surrounding structures. This case highlights the utility of cardiac gated computed tomography for cases of suspected valvular perforation when echocardiography is not readily available or inadequate imaging is obtained.

Anterior mediastinal mass biopsy and resection: anesthetic techniques and perioperative concerns.

The perioperative management of the patient with an anterior mediastinal mass (AMM) is viewed as one of the more challenging anesthetic endeavors. Diligent preoperative planning is essential and often involves imaging studies using multiple modalities, pulmonary function assessment, and minimally invasive biopsy for tissue diagnosis prior to arriving in the operating room. Anesthetic induction, often without major risks in most patients, can be catastrophic in AMM patients, with possible complications that include complete airway obstruction and cardiovascular collapse. The authors present the case of a biopsy via anterior mediastinotomy under monitored anesthesia care (MAC)/sedation in a 39-year-old man, who presented with a large AMM causing significant right heart compression without tracheobronchial involvement. This procedure was followed by definitive mass resection approximately 6 weeks later. This review will explore the following: (1) the use of MAC/sedation for AMM biopsy, (2) methods of safely securing the airway in patients undergoing definitive mass resection via median sternotomy, (3) current opinions regarding the need for preoperative pulmonary function testing in these patients, (4) current opinions regarding the need for and timing of cardiopulmonary bypass in these cases, (5) the use of intraoperative transesophageal echocardiography during resection, and (6) the characteristics of mediastinal germ-cell tumors with sarcomatous conversion. Though multiple anesthetic methods have been proposed for the management of patients undergoing tissue biopsy and resection of an AMM, this case report presents 2 successful anesthetic options for 2 distinct surgical procedures. In every instance, the anesthetic management options must be tailored to the unique physiological needs of the patient presenting for surgery.

Reversal of flow in the pulmonary artery: high-pitch spiral as a new method for dose reduction in functional imaging.

Advancements in CT technology lave led to substantial dose reductions for anatomic imaging of the heart. Here we illustrate an example where rapid repeat imaging with a high pitch spiral technique can image physiologic function. By optimal timing, and repeat sub second scanning, we illustrate an unusual case where direction of blood flow in the right pulmonary artery is reversed.

The association of epicardial adipose tissue with coronary artery calcification among HIV-infected men.

Little data exist regarding the association of epicardial adipose tissue (EAT) and cardiovascular disease among HIV-infected persons. Among 213 HIV-infected men, there was a significant association between protease inhibitor use and increasing EAT volume. EAT was significantly associated with coronary artery calcium greater than 100. The elevated coronary artery disease risk in HIV-infected men may be partially explained by EAT associated with protease inhibitor use.

Gerbode defect with Staphylococcus lugdunensis native tricuspid valve infective endocarditis.

Coagulase-negative staphylococci are generally not considered to be very virulent; they are an uncommon cause of native valve endocarditis. Staphylococcus lugdunensis is an important exception and causes more severe infections, clinically mimicking S. aureus. We present a case of direct Gerbode defect associated with S. lugdunensis native valve infective endocarditis (IE) requiring cardiac surgery.