Dual-energy chest radiography has the potential to provide better diagnosis of lung disease by removing the bone signal from the image. Dynamic dual-energy radiography is now possible with the introduction of digital flat-panel detectors.

The purpose of this study is to evaluate the feasibility of using dynamic dual-energy chest radiography for functional lung imaging and tumor motion assessment. The dual-energy system used in this study can acquire up to 15 frames of dual-energy images per second. A swine animal model was mechanically ventilated and imaged using the dual-energy system. Sequences of soft-tissue images were obtained using dual-energy subtraction. Time subtracted soft-tissue images were shown to be able to provide information on regional ventilation. Motion tracking of a lung anatomic feature (a branch of pulmonary artery) was performed based on an image cross-correlation algorithm. The tracking precision was found to be better than 1 mm. An adaptive correlation model was established between the above tracked motion and an external surrogate signal (temperature within the tracheal tube). This model is used to predict lung feature motion using the continuous surrogate signal and low frame rate dual-energy images (0.1-3.0 frames per second). The average RMS error of the prediction was (1.1 ± 0.3) mm.

The dynamic dual energy was shown to be potentially useful for lung functional imaging such as regional ventilation and kinetic studies. It can also be used for lung tumor motion assessment and prediction during radiation therapy.

In recent years, there have been significant advances in the management of patients with lung cancer. This progress is associated with increased use of medical intensive care units (ICUs) for the management of a variety of complications related to cancer, its treatment, or comorbid illnesses. At the same time, there are advances in the care of critically ill patients in general.

Over the last decade, there are several studies that report progressive improvement in the outcome of lung cancer patients admitted to the medical ICUs. On average, the ICU and hospital mortality rates of lung cancer patients are 36% and 51%, respectively. These rates are approaching those of critically ill general population. However, it is clear that not all lung cancer patients will benefit from this aggressive care. Although there are no absolute predictors, the current evidence suggests that advanced refractory cancer, poor baseline performance status, the need for mechanical ventilation, and multiple organ system failures are factors associated with worse ICU outcome.

Further studies are needed to better triage patients who are going to benefit from ICU care; determine the optimal duration of this care; and assess the impact of this therapy on the long-term survival, cancer treatment, and quality of life of these patients.

In critically ill patients, endotracheal intubation is associated with a high risk of complications, including severe hypoxemia and hypotension. The purpose of this review is to discuss the definitions, complications, airway assessment, and patient optimization with respect to these patients. In addition, we present different approaches and techniques to help secure the airway in critically ill patients.

We also discuss strategies to help minimize the risk of a difficult or failed airway and to mitigate the severe life-threatening complications associated with this high-risk procedure.

Pregnancy induces marked changes in the respiratory and cardiovascular systems that are essential for meeting the increased metabolic demands of the mother and fetus. Important respiratory system changes occur in the upper airway, chest wall, static lung volumes, and ventilation and gas exchange. Marked cardiovascular changes also occur during pregnancy including increased plasma volume, increased cardiac output, and reduced vascular resistance.

Knowledge of these physiologic adaptations is necessary for the clinician to distinguish the common "physiologic dyspnea" from disease states that occur during pregnancy.