Although pulmonary artery (PA) dilation is independently associated with significant morbidity and mortality in patients with pulmonary diseases irrespective of diagnosed pulmonary hypertension, its relationship with nontuberculous mycobacteria (NTM) is unknown. The Bronchiectasis and NTM Research Registry is a multicenter registry created to foster research in non-cystic fibrosis (CF) bronchiectasis and NTM lung disease. The majority of patients with non-CF bronchiectasis at Oregon Health & Science University have NTM infections. To determine the prevalence of PA dilation in these patients and its association with supplemental oxygen use, severity of bronchiectasis, tobacco use, and NTM in the sputum culture, we evaluated the chest computed tomography (CT) scans from 321 patients in a cross-sectional analysis. We measured the severity of bronchiectasis by applying modified Reiff criteria and measured the diameters of the PA and aorta (Ao), with PA dilation defined as a PA:Ao ratio >0.9. In our cohort, the mean age was 67.3 years and 83.2% were female. The mean modified Reiff score was 7.1, indicating moderate disease severity. Forty-two patients (13.1%) were found to have PA dilation. PA dilation was positively associated with the use of supplemental oxygen (P<0.001), but there was no association between PA dilation and NTM infection.

Chest radiography serves a crucial role in imaging of the critically ill. It is essential in ensuring the proper positioning of support and monitoring equipment, and in evaluating for potential complications of this equipment. The radiograph is useful in diagnosing and evaluating the progression of atelectasis , aspiration, pulmonary edema, pneumonia, and pleural fluid collections. Computed tomography can be useful when the clinical and radiologic presentations are discrepant, the patient is not responding to therapy, or in further defining the pattern and distribution of a radiographic abnormality.

Purpose Narrow PTV margins and steep dose gradients underscore the importance of evaluating breathing-associated tumor motion for lung SBRT. The specific aim of this study was to determine the impact of anatomic tumor location on inter-fraction tumor motion. Methods and Materials Forty-one patients underwent standard free-breathing 4DCT simulation and daily image-guidance 4DCTs during lung SBRT. Absolute tumor motion amplitude in the mediolateral (ML), anterior-posterior (AP), and superior-inferior (SI) directions was analyzed from 159 total 4DCT scans (simulation and daily pre-treatment). Results Overall, the inter-fraction tumor motion amplitude in the ML, AP, and SI directions was small (mean ≤2.5 mm). Similarly, while both upper lobe (UL) and lower lobe (LL) tumors exhibited limited inter-fraction motion in both the ML and AP directions (mean ≤2.2 mm), tumors in the LL had increased inter-fraction motion in the SI direction compared to UL tumors (mean 4.3±4.0 mm vs. 1.7±1.7 mm, p=0.008). Moreover, 28.6% (n=4) of LL tumors exhibited mean inter-fraction motion along the SI direction >5 mm (all of which resided in the supra-diaphragmatic basal segments of the LL). Conclusions Mean inter-fraction tumor motion amplitude along the SI direction exceeded our PTV margins (an isotropic 5 mm expansion of the ITV) in 28.6% of LL tumors (all of which resided in the basal segments). These results suggest that typical ITV-to-PTV margins may be insufficient for a subset of LL lesions and that increased PTV margins, daily breathing motion re-assessment and/or adaptive re-planning may benefit patients with supra-diaphragmatic tumors in the LL.

Diagnostic imaging for acute pulmonary embolism has evolved; CT angiography of the chest is now considered the gold standard for diagnosis. The chest radiograph has limited utility, but can occasionally detect an alternative diagnosis. Although not frequently used, ventilation/perfusion scan can be diagnostic, particularly in the setting of a normal chest radiograph. Clinical features, including risk factors and presenting signs and symptoms, should be utilized to assess pre-test probability and guide diagnostic imaging choices. Unique situations, such as renal failure and pregnancy, will potentially alter the diagnostic decisions.

Induced hypothermia is a technique that has gained popularity as an adjuvant therapy for patients with traumatic brain injuries, refractory arrhythmias, cardiac arrest and myocardial infarction. Induced hypothermia in patients with cardiogenic shock could improve the recovery of a stunned myocardium by decreasing its metabolic demands. We report a patient who presented with cardiogenic shock after surgical replacement of both aortic and mitral valves. The patient was placed in induced hypothermia for 34 hours. The clinical course was followed using measurements of arterial blood gas concentrations, serum lactate levels and transthoracic echocardiograms. During mechanical ventilation, the patient was monitored using a bedside bispectral index state of consciousness and temperature was measured using a Swan-Ganz catheter. The requirements for vasoactive drugs declined considerably during the hypothermic and rewarming periods. Echocardiography showed improvements in the left ventricle ejection fraction from 30% to 60% in the rewarming period with improvement in the mobility of both the anterior and septal walls. Induced hypothermia could be considered as part of the management strategy for patients with cardiac surgery, extracorporeal circulation and cardiogenic shock.

We describe a direct and accurate method for defining chest radiographic anatomy and use this method to delineate the anatomic composition of the right mediastinal border in an adult population. Intravenous contrast-enhanced computed tomographic scans of the chest and accompanying scout tomograms from 99 adults without previously known or detected cardiopulmonary disease that could potentially distort mediastinal, cardiac, or pulmonary anatomy were retrospectively evaluated. Transverse CT images through the mediastinum were directly referenced to the respective acquisition location on the scout tomogram via the acquisition reference line. The anatomic composition of the right mediastinal border on the scout tomogram was determined by drawing a vertical line tangential to the most lateral right mediastinal structure in each transverse CT image. The lengths and relationships of these structures were tabulated. These results will help to create a consensus among radiologists and other clinicians regarding radiographic anatomy, allowing improved localization of mediastinal pathology and enabling more optimal positioning of vascular and cardiac support devices.

Chest radiography serves a crucial role in imaging of the critically ill. Its uses include diagnosis and monitoring of commonly encountered pulmonary parenchymal and pleural space abnormalities. It is also important in evaluating monitoring and support devices and associated complications. CT, another useful imaging modality in select patients, can better characterize pulmonary parenchymal and pleural space disease.

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.

Mycobacterium tuberculosis infection in non-human primates parallels human tuberculosis, and provides a valuable vaccine evaluation model. However, this model is limited by the availability of real-time, non-invasive information regarding disease progression. Consequently, we have combined computed tomography scanning with enumeration of antigen-specific T cell responses. Four rhesus monkeys were infected with M. tuberculosis strain H37Rv (1000 cfu) in the right lower lobe via a bronchoscope. All uniformly developed progressive tuberculosis, and required euthanasia at 12 weeks. Computed tomography scanning provided detailed real-time imaging of disease progression. At necropsy, computed tomography and pathohistologic findings were tightly correlated, and characteristic of human disease. Immunologic monitoring demonstrated progressive evolution of high frequency M. tuberculosis-specific CD4(+) and CD8(+) T cell responses. Peripheral blood effector cell frequencies were similar to those observed in tissues. In summary, computed tomography scanning in conjunction with immunologic monitoring provides a non-invasive, accurate, and rapid assessment of tuberculosis in the non-human primate.

Temporary coverage of severely burned patients with cadaver allograft skin represents an important component of burn care, but is limited by availability and cost. Porcine skin shares many physical properties with human skin, but is susceptible to hyperacute rejection due to preformed antibodies to α-1,3-galactose (Gal), a carbohydrate on all porcine cells. Our preliminary studies have suggested that skin grafts from α-1,3-galactosyltransferase knock out (GalT-KO) miniature swine might provide temporary wound coverage comparable to allografts, since GalT-KO swine lack this carbohydrate. To further evaluate this possibility, eight non-human primates received primary autologous, allogeneic, GalT-KO, and GalT + xenogeneic skin grafts. Additionally, secondary grafts were placed to assess whether sensitization would affect the rejection time course of identical-type grafts. We demonstrate that both GalT-KO xenografts and allografts provide temporary coverage of partial- and full-thickness wounds for up to 11 days. In contrast, GalT + xenografts displayed hyperacute rejection, with no signs of vascularization and rapid avulsion from wounds. Furthermore, secondary GalT-KO transplants failed to vascularize, demonstrating that primary graft rejection sensitizes the recipient. We conclude that GalT-KO xenografts may provide temporary coverage of wounds for a duration equivalent to allografts, and thus, could serve as a readily available alternative treatment of severe burns.

Noninvasive Cystic Thymoma in an Adolescent BoyPeter T. Verhey1, Katharine L. Hopkins1, Steven L. Primack1, Nicholas Radovich2 and Andrew Zigman3Audio Available | Share

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.

Diaphragmatic injuries occur in 0.8%-8% of patients after blunt trauma. Although the diagnosis may be obvious at standard chest radiography or computed tomography (CT) in most situations, some more subtle signs require careful analysis of CT images and examination with magnetic resonance (MR) imaging in some specific situations. Each method of imaging evaluation has advantages and pitfalls according to the type of diaphragmatic rupture. MR imaging with breath-hold acquisition permits good visualization of diaphragmatic abnormalities, but this technique cannot be performed in emergency situations. Because of a dramatic reduction in motion and beam-hardening artifacts and significant improvement of spatial resolution, especially along the z axis, helical CT and multisection CT allow better demonstration of the most subtle signs, such as a focal indentation of the liver or a right-sided collar sign. In addition, helical CT and multisection CT are useful tools in the evaluation of patients with multiple traumatic injuries.

The aim of this study was to determine the likelihood of malignancy in small nodules in the nonprimary lobe in patients with resectable bronchogenic carcinoma. In 141 patients who underwent curative resection of bronchogenic carcinoma and had adequate follow-up CT examinations, the presence of small nodules in the nonprimary lobe preoperatively and change of preexisting nodules, if any, was assessed. The criteria used to determine benignity of a nodule was stability or decrease in size for 24 months on CT. Histopathology of the nodules was reviewed for an additional 10 patients who underwent surgical biopsy for an accompanying nodule before curative surgery. Sixty-two (44%) of 141 patients had a total of 138 small (≤ 10 mm) nodules in the nonprimary lobes (< 5 mm in 113, 5–10 mm in 25). Of these 138 nodules, 132 were benign with only six nodules malignant (with histopathologic confirmation for the enlarging nodules). The 132 benign nodules showed no change (n = 120), decrease in size (n = 11), or increase in size (n = 1) on follow-up studies, with the single enlarging nodule proved benign on biopsy. In 10 patients who had a preoperative biopsy of a single preexisting nodule in the nonprimary lobe (< 5 mm = 1; 5–10 mm = 5; > 10 mm = 4) two proved to be malignant (both > 10 mm) and eight were benign. Most small (< 10 mm) nodules associated with resectable bronchogenic carcinoma are benign, consistent with published results of other studies. However, a small number of nodules are malignant and CT does not reliably distinguish between benign and malignant nodules.