Tag: carcinoma

Tracheobronchial Tree Many methods have been used to evaluate airway obstruction. The most often used is conventional radiography. A recent study in pediatric patients demonstrated MR images in the sagittal and axial plane allowed clear demonstration of tracheal compression and narrowing secondary to a variety of etiologies. Correlation with endoscopy showed the appearance on MR […]

Pulmonary Vascularity Since the introduction of MR there has been some interest in the use of MR in the evaluation of the pulmonary arteries in order to allow detection of pulmonary embolism and/or thrombus. Studies have been performed both in the animal model and in humans presenting with pulmonary embolus and/or thrombus.’ The experiments in […]

When evaluating patients following radiation therapy it is important to recall the time course of radiation-induced changes within the lungs. In the early stages, seen 6 to 12 weeks after radiation, there is an acute reaction termed radiation pneumonitis. The late or chronic phase of radiation change is associated with replacement of normal lung parenchyma […]

Mediastinoscopy provided a sensitivity of 87.1 percent, specificity of 100 percent and an accuracy of 95.2 percent. Mediastinoscopy in this study exceeded all the other modalities as the most accurate staging method for detecting bronchogenic carcinoma. Another study evaluating primary lung carcinoma staging comparing MR and CT found no statistically significant differences between the two […]

Pulmonary Parenchyma As described previously, on MR the lungs are seen as regions of low (black) signal intensity. An abnormality within the lung parenchyma results in a region of increased signal intensity. Recently, a study evaluated the capabilities of MR in relation to CT for the detection of pulmonary nodules. This study showed that pulmonary […]

Evaluation of the mediastinum and hilum are the primary areas where magnetic resonance excels. The blood vessels and tracheobronchial tree are both visualized as regions of signal void highlighted by the surrounding fat. Masses in these regions have sufficiently unique imaging characteristics to allow differentiation from the normal structures and fat (Fig 4). This is […]

Thoracic Inlet MR is useful for evaluation of lesions that arise or extend into the thoracic inlet. Often with CT it is difficult to evaluate this region due to the streak artifacts caused by the surrounding bony structures. Additionally, unless an adequate bolus of contrast medium is given, the effect of the masses on the […]

Some of the disadvantages of magnetic resonance for imaging of the chest include a prolonged data acquisition time, partial volume averaging, and limited ability to visualize calcium. Also, pleural effusions may not be as easily visualized with MR because visualization depends upon the type of pulse sequence chosen. By prolonging the TR of the pulse […]

On non-contrast CT studies, the aorta and pulmonary arteries are seen as gray attenuation that have a different appearance from fat. On MR, when there are masses within the mediastinum, the blood vessels are seen as low signal intensity, while the masses have an intermediate signal intensity. In contradistinction, on a noncontrast CT study, the […]

In order to obtain adequate images of the structures within the thorax, ECG gating is necessary. The gating techniques allow multi-slice acquisition. In the standard spin echo gated MR technique, multiple levels are acquired from thoracic inlet to diaphragm. Images of the heart are obtained at different phases in the cardiac cycle with this technique. […]