In Situ Pulmonary Arterial Thrombosis: Literature Review and Clinical Significance of a Distinct Entity.

Filling defects identified in the pulmonary arterial tree are commonly presumed to represent an embolic phenomenon originating from thrombi formed in remote veins, particularly lower-extremity deep venous thrombosis (DVT). However, accumulating evidence supports an underappreciated cause for pulmonary arterial thrombosis (PAT), namely, de novo thrombogenesis-whereby thrombosis arises within the pulmonary arteries in the absence of DVT. Although historically underrecognized, in situ PAT has become of heightened importance with the emergence of SARS-CoV-2 infection. In situ PAT is attributed to endothelial dysfunction, systemic inflammation, and acute lung injury and has been described in a range of conditions including COVID-19, trauma, acute chest syndrome in sickle cell disease, pulmonary infections, and severe pulmonary arterial hypertension. The distinction between pulmonary embolism and in situ PAT may have important implications regarding management decisions and clinical outcomes. In this review, we summarize the pathophysiology, imaging appearances, and management of in situ PAT in various clinical situations. This understanding will promote optimal tailored treatment strategies for this increasingly recognized entity.

Preparation for an Half-Ironmantm Triathlon amongst Amateur Athletes: Finishing Rate and Physiological Adaptation.

Long distance triathlon has gained in popularity amongst the general population. Coaches establish training programs based upon their knowledge, personal experience and on current training principles. The goal was to observe the effect of a triathlon training program for a half Ironman event in neophyte amateur athletes. A specific triathlon training program was followed from February to June 2016 by a group preparing for their first half ironman. Out of the 32 participants (19 Males and 13 Females; mean age of 39 ± 9.9 years old; body weight of 72.7 ± 13.4 kg and a height of 171.5 ± 10.2 cm), only one did not complete the event. A mean training volume of 410 ± 201 min per week led to a mean finishing time of 6 hours 28 minutes. The training program significantly increased the maximal oxygen consumption (45.9 ± 8.2 to 48.6 ± 7.5 ml/kg/min, p =0.002) and the maximal power output (293.1 ± 63.7 to 307.8 ± 58.7 W, p < 0.001). The absolute oxygen consumption and power output at both ventilatory thresholds also significantly increased (VT1: 2.2 ± 0.4 to 2.5 ± 0.5 L, p = 0.001; 157.8 ± 41.8 to 176.7 ± 41.1 W p = 0.009 and VT2: 2.9 ± 0.4 to 3.0 ± 0.4 L, p = 0.017; 229.3 ± 62.0 to 244.8± 55.2 W, p = 0.022 ). A significant diminution of waist circumference was observed (83.2 ± 10.0 to 81.8 ± 9.5 cm, p = 0.032) with no significant changes in body weight. Thus, a 24-week specific training program appears to be safe and efficient for amateur athletes aiming to finish their first half- Ironman event.

Canadians vulnerable to workplace noise.

BACKGROUND: Health and safety legislation is designed to protect workers from hazards, including excessive noise. However, some workers are not required to use hearing protection when exposed to loud noise and may be vulnerable to adverse outcomes, including hearing difficulties and tinnitus. DATA AND METHODS: Data for 19- to 79-year-olds (n=6,571) were collected from 2012 through 2015 as part of the Canadian Health Measures Survey. People exposed to loud workplace noise were defined as those who had to raise their voices to communicate at arm's length. Vulnerable workers were defined as those who were not required to use hearing protection when working in noisy environments and who only used hearing protection sometimes, rarely or never. RESULTS: An estimated 11 million Canadians (43%) have worked in noisy environments, and over 6 million of them (56%) were classified as vulnerable to workplace noise. Although the percentage of vulnerable women (72%) was greater than that of men (48%), men outnumbered women in these circumstances at 3.7 million, compared with 2.4 million. The self-employed were more likely than employees to be vulnerable, as were those in white-collar versus blue-collar occupations. Vulnerable workers were more likely to report hearing difficulties and tinnitus than those who had never worked in a noisy environment. DISCUSSION: A large percentage of workers exposed to noisy workplaces were vulnerable because hearing protection was neither required nor routinely used. Further work is required to assess whether this reflects gaps in health and safety legislation or its implementation.

Imaging of cardiac herniation in traumatic pericardial rupture.

Cardiac herniation as a result of traumatic pericardial rupture is a serious injury and a difficult diagnosis to make on radiographic studies. Even with the more advanced imaging modalities, this rare diagnosis remains challenging. In a high-energy traumatic setting, there are chest radiograph and multidetector computed tomography findings that are strongly suggestive of cardiac herniation. The imaging, along with greater awareness of this injury, may provide a more rapid diagnosis, thus potentially preventing the severe clinical deterioration often seen in these patients.

Atelectasis after free rectus transfer and abdominal wall reconstruction.

BACKGROUND: Atelectasis is commonly encountered in patients undergoing rectus abdominus tissue transfer. Primary closure of the anterior rectus sheath may contribute to this process. Augmentation of the closure with mesh may decrease the incidence of Atelectasis. METHODS: In this retrospective review 32 patients with preoperative and postoperative augmentation were compared to 23 who had primary closure of the anterior rectus sheath. RESULTS: Augmentation consisted of acellular dermis (25) or mesh (7). Postoperative atelectasis was radiographically detected in: 91% (n=29) of augmented patients versus 83% (n=19) of primary closure patients. Major atelectasis in 41% (n=13) of augmented patients versus 61% (n=14) of primary closure patients p<.05. The incidence of atelectasis was independent of skin flap size and operative times. CONCLUSIONS: The use of acellular dermis or mesh to augment the abdominal wall appears to reduce the high incidence of postoperative atelectasis following rectus-free flap harvest.

CT angiography in the evaluation of acute pulmonary embolus.

OBJECTIVE: The purpose of this study was to assess the appropriate use of CT angiography (CTA) in the diagnostic evaluation of acute pulmonary embolism (PE). MATERIALS AND METHODS: We reviewed a total of 575 CT angiograms obtained to evaluate for PE at a large level 1 trauma teaching hospital from January 2004 through March 2005. Various clinical settings were used for 267 inpatient (46%), 258 emergency department (45%), and 50 outpatient (9%) studies. We excluded CTA performed for other reasons, repeated CTA, and patient records with incomplete clinical data. On the basis of chart review in which the investigators were blinded to final diagnoses, pretest probability of PE according to the Wells criteria was retrospectively assigned to each patient. D-dimer values, when obtained, also were reviewed. The diagnosis of PE was based on final CTA reports. RESULTS: PE was diagnosed in 9.57% of 575 patients. Positivity rates by location were 32 (12%) of the 267 inpatients, 22 (8.5%) of the 258 emergency department patients, and one (2.0%) of the 50 outpatients. Three (< 1%) of the 575 patients had high probability of PE, even though 351 patients had gone directly to CTA. Of the other 572 patients, 158 (28%) had intermediate and 414 (72%) low probability of PE. In the high, intermediate, and low probability groups, two (67%), 24 (15%), and 29 (7%), respectively, of the patients had PE. A D-dimer assay was performed for 224 (39%) of the 575 patients. Thirty-nine (17%) of the 224 patients had normal results (< 0.5 microg/mL); 107 (48%), intermediate results (0.6-2.0 microg/mL); and 78 (35%), abnormal results (> 2.0 microg/mL). In the emergency department cohort, 151 (59%) of 258 patients underwent a D-dimer assay. Thirty-two (21%) of the 151 patients had normal results; 81 (54%), intermediate results; and 38 (25%), abnormal results. Only one patient with a normal D-dimer level and three patients with intermediate D-dimer levels had PE, the equivalent of 3% of each group. The number of CTA examinations ordered for patients with normal and intermediate D-dimer results was 146 (25% of the 575 total studies). Twenty-two (8%) of the 258 emergency department patients had PE, and clinical suspicion of PE was high for 11 (50%), intermediate for 10 (45%), and low for one (5%) of those patients. CONCLUSION: Our data showed suboptimal use of the Wells criteria and subjective overestimation of the probability of PE before ordering of CTA. Although a definitive acceptable PE positivity rate for CTA has not been established, the 10% yield represents overuse of CTA as a screening rather than a diagnostic examination.

Differentiating diaphragmatic paralysis and eventration.

RATIONALE AND OBJECTIVES: Although elevation of the diaphragm can be appreciated on conventional PA and lateral chest radiography, the modality is commonly viewed as inadequate to differentiate diaphragmatic paralysis from eventration. Our objective was to qualitatively and quantitatively measure the utility of chest radiography in determining the presence or absence of diaphragmatic paralysis in patients with an elevated diaphragm. MATERIALS AND METHODS: A retrospective analysis of chest radiographs in 32 patients, whom underwent fluoroscopic sniff test for elevated diaphragm, was performed. Diaphragm function was graded by a senior radiology resident, as either "paralyzed" or "non-paralyzed," based on appearance/shape of elevated hemidiaphragm on PA and lateral radiograph. The diaphragm position and shape for all patients were determined using measurements relating to skeletal structures and radius of curvature, respectively. These results were correlated with the results of the fluoroscopic sniff tests. RESULTS: Of 32 patients with elevated diaphragm on chest radiograph, 17 had diaphragmatic paralysis confirmed with fluoroscopic sniff test. Our results indicate that the radius of curvature or shape of the diaphragm on lateral chest radiograph is the most important factor for detection of the presence or absence of diaphragmatic paralysis. HH/APD > 0.28 suggests against paralysis. CONCLUSION: Conventional chest radiography appears to be a useful modality for assessment of the functional status of an elevated diaphragm. Based on our results, evaluation of the shape of an elevated diaphragm may preclude the need for fluoroscopic sniff test to determine diaphragmatic paralysis.

Trace metal concentrations in Posidonia oceanica of North Corsica (northwestern Mediterranean Sea): use as a biological monitor?

BACKGROUND: Within semi-closed areas like the Mediterranean Sea, anthropic wastes tend to concentrate in the environment. Metals, in particular, are known to persist in the environment and can affect human health due to accumulation in the food chain. The seagrass Posidonia oceanica, widely found in Mediterranean coastal waters, has been chosen as a "sentinel" to quantify the distribution of such pollutants within the marine environment. Using a technique similar to dendrochronology in trees, it can act as an indicator of pollutant levels over a timeframe of several months to years. In the present study, we measured and compared the levels of eight trace metals (Cr, Ni, Cu, Zn, As, Se, Cd, and Pb) in sheaths dated by lepidochronology and in leaves of shoots sampled from P. oceanica meadows collected from six offshore sites in northern Corsica between 1988 and 2004; in the aim to determine 1) the spatial and 2) temporal variations of these metals in these areas and 3) to compared these two types of tissues. RESULTS: We found low trace metal concentrations with no increase over the last decade, confirming the potential use of Corsican seagrass beds as reference sites for the Mediterranean Sea. Temporal trends of trace metal concentrations in sheaths were not significant for Cr, Ni, Cu, As or Se, but Zn, Cd, and Pb levels decreased, probably due to the reduced anthropic use of these metals. Similar temporal trends between Cu levels in leaves (living tissue) and in sheaths (dead tissue) demonstrated that lepidochronology linked with Cu monitoring is effective for surveying the temporal variability of this metal. CONCLUSION: Leaves of P. oceanica can give an indication of the metal concentration in the environment over a short time period (months) with good accuracy. On the contrary, sheaths, which gave an indication of changes over long time periods (decades), seem to be less sensitive to variations in the metal concentration in the environment. Changes in human consumption of metals (e.g., the reduction of Pb in fuel) are clearly reflected in both organs. These results confirm that P. oceanica is a good bioindicator of metals and a good biomonitor species for assessing Cu in the environment.

Recurrent acute profound thrombocytopenia related to readministration of eptifibatide.

We describe the case of an 86-year-old woman who presented with unstable angina. She was given heparin and eptifibatide, and she underwent percutaneous coronary intervention (PCI). Shortly thereafter, she developed acute profound thrombocytopenia (6,000 platelets/mm3), which resolved after the discontinuation of heparin and eptifibatide. Four months later, she presented again with unstable angina and underwent PCI. Soon after the procedure, she again developed acute profound thrombocytopenia (2,000 platelets/mm3). To our knowledge, acute profound thrombocytopenia due to eptifibatide treatment in the same patient at two different times has not been reported before.

Cervical thoracic duct cyst.

Thoracic duct cysts are rare lesions presenting as mediastinal or supraclavicular masses. We report a case of a 77-year-old female who presented with a left supraclavicular mass. A cervical thoracic duct cyst was suspected after contrast-enhanced computed tomography (CT) of the neck and chest. Diagnosis was confirmed by ultrasound-guided cyst aspiration and lymphangiography. Therapeutic embolization of the thoracic duct was unsuccessful. Definitive treatment was achieved with thoracic duct ligation using video-assisted thoracoscopic surgery (VATS) followed by surgical excision of the cyst. This is believed to be the first report of using minimally invasive surgery for thoracic duct ligation in the treatment of a thoracic duct cyst.

Lymphocytic interstitial pneumonitis in a patient with systemic lupus erythematosus: radiographic and high-resolution CT findings.

Reports associating lymphocytic interstitial pneumonitis (LIP) and systemic lupus erythematosus (SLE) are exceedingly rare. This case demonstrates high-resolution CT (HRCT) findings of LIP including multiple thin-walled cysts throughout the lungs, which are known to occur in LIP, but have not been described in the radiologic literature in association with SLE.

Multidetector pulmonary CT angiography: advances in the evaluation of pulmonary arterial diseases.

Multidetector CT (MDCT) has a primary role in the evaluation of pulmonary artery diseases. Contrast-enhanced MDCT studies are ideally suited for assessment of pulmonary arterial hypertension (PAH) and pulmonary thromboembolic disease. It has become the primary modality to diagnose acute and chronic thromboembolic disease. Its role in the evaluation of pulmonary hypertension is evolving, allowing the radiologist to assess the presence of disease and differentiating intrinsic versus extrinsic pulmonary arterial pathology. An understanding of pulmonary CT angiography, its appropriate application, associated pitfalls, contrast dynamics, and thin-section CT pulmonary and cardiac anatomy is necessary for accurate interpretation by the radiologist. In addition to assessing the pulmonary arteries MDCT has the implicit advantage of thin-section lung parenchymal imaging, a feature that often renders an alternative diagnosis when symptoms of pulmonary arterial disease occur.

Contrast dynamics during CT pulmonary angiogram: analysis of an inspiration associated artifact.

OBJECTIVE: Several artifacts have been observed during contrast-enhanced CT of the pulmonary arteries. We describe a physiological artifact caused by a transient interruption of the contrast column in the pulmonary arteries associated with inspiration immediately prior to imaging. This results from a variable inflow of unopacified blood from the inferior vena cava (IVC). MATERIALS AND METHODS: From 327 consecutive pulmonary CT-angiograms, all performed on a single detector scanner at 3 mm collimation (1.5 mm incremental reconstruction), 50 positive studies, 46 indeterminate studies, and 33 negative studies (129 exams) were retrospectively reviewed by a blinded observer to determine the frequency of the described contrast interruption, its severity (mild, moderate, or severe), and its possible contribution to misinterpretation of studies. The numerical change in Hounsfield units was assigned within the right ventricular chamber for each examination to correlate with the subjective evaluation of severity. Statistical significance was determined with P = 0.05%. RESULTS: The artifact was present in 48 (37.2%) of the 129 evaluated studies. It was greater in frequency (50.0%) with the negative studies. The presence was 25% with positive studies and 36.7% with indeterminate exams. The interruption was more often mild (<100 HU change) in severity (45.8%). Three (6.6%) definite false positives were detected where the misinterpretation was directly attributed to the artifact. Three (6.6%) other examinations called positive were also directly related to the interrupted contrast column. However, since no further pulmonary vascular evaluation was performed, these examinations can only be considered indeterminate. Two of the latter 3 studies demonstrated a severe (>150 HU change) and the other study demonstrated a moderate (100-150 HU) interruption of contrast opacification. CONCLUSIONS: During inspiration, there is a variable increase in unopacified venous blood from the IVC, briefly diluting the contrast column entering from the SVC. This interruption is common, though usually mild in severity. However, a short severe interruption of vascular opacification can lead to misinterpretation as a pulmonary embolus or contribute to an indeterminate examination.

Pulmonary Langerhans cell histiocytosis: emerging concepts in pathobiology, radiology, and clinical evolution of disease.

Pulmonary Langerhans cell histiocytosis (PLCH) is an uncommon disorder of adult smokers associated with a significant morbidity. Arising from the aberrant accumulation of Langerhans and other immune cells, PLCH tends to cause a relatively isolated pulmonary involvement as compared to other forms of Langerhans cell (LC) and histiocytic disorders. Increased knowledge of cytokine triggers, dendritic cell trafficking, and clonality of LC populations in PLCH have resulted in an improved understanding of the pathobiology of PLCH. High-resolution CT (HRCT) of the chest has led to better appreciation of nodular and cystic radiographic abnormalities characteristic of the disease. Correlation of HRCT abnormalities with lung pathologic changes has led to an improved comprehension of clinical evolution of PLCH. Current clinical predictors for PLCH outcomes remain poor, although long-term follow-up and radiologic monitoring may help to define disease progression. This review discusses advances in PLCH emphasizing the etiopathologic bases of the disease and currently available radiologic modalities for monitoring disease progression.

Approach to ground-glass opacification of the lung.

There area number of diseases that present with ground-glass opacification of the lung as a primary manifestation on chest radiography and thin-section computed tomography (CT). These diseases cannot be clearly categorized into the classic classification scheme of airspace and interstitial disease because there are features of both categories seen in the imaging and histologic findings. Ground-glass opacification has, therefore, been categorized as nonspecific by many radiologists. The fact that both the airspaces and interstitial tissues are often involved should have little importance when evaluating radiographs or high-resolution CT (HRCT) images. The role of the radiologist is evolving and is becoming more significant in the clinical evaluation of a patient presenting with so-called interstitial lung disease. In this article, an approach is described that hopefully will lead to an effective and narrow differential diagnosis when a radiologist is confronted with ground-glass opacification. The critical features in evaluating such cases include: (1) the duration of clinical symptoms; (2) the presence or absence of lung fibrosis, especially honeycombing; (3) the patient's history of smoking; and (4) the distribution of the disease. Each of these features is considered in this article in conjunction with the diseases that lead to ground-glass opacification. The recent thinking regarding nonspecific interstitial pneumonia and usual interstitial pneumonia also is discussed.

The radiological spectrum of small-airway diseases.

The small airways of the lungs are an often misunderstood and confusing anatomic location teeming with an array of similar-appearing disease processes that can be daunting even to the most experienced radiologist. This article shows that an understanding of small-airway anatomy and accurate pattern recognition can allow one to determine useful clinical differential diagnoses. The ability to recognize mosaic lung attenuation, and the presence of centrilobular nodules and reticular opacities (tree-in-bud), with or without ground glass, is of critical importance in evaluating this portion of the lung. In addition, we attempt to further show how high-resolution computed tomography (HRCT) scanning has opened the deep recesses of the lung to the thoracic radiologist, allowing for a more meaningful radiologic contribution to the clinical care of patients with unexplained pulmonary symptomatology.