Faculty Bibliography

Optimal clinical management of patients with focal lung pathology necessitates thorough familiarity with basic concepts in imaging. Over the past decade, radiologic evaluation has undergone rapid change, reflecting considerable growth in imaging technology. As this article discusses and illustrates at length, improvements in computed tomography technology in particular have resulted in a significant alteration in our approach to both the diagnosis and treatment of patients with focal lung disease

In our experience, MR has served largely as a problem-solving device, especially in those cases in which CT has proved equivocal. Magnetic resonance has been especially efficacious in evaluating cardiovascular pathology. Virtually the entire spectrum of aortic disease can be assessed accurately, making MR a reasonable alternative to CT or angiography in most cases. Indications for the use of MR in patients with thoracic neoplasia have also emerged. Magnetic resonance is more accurate than CT in assessing invasion of the chest wall and mediastinum. As a consequence, MR should be considered the imaging procedure of choice in patients with suspected Pancoast tumors. In some patients with lymphoma, MR can make a unique contribution by evaluating the response to therapy. Magnetic resonance also can be of value in assessing patients with signs of venous obstruction, especially when there is a contraindication to the use of intravenous contrast medium. Magnetic resonance is as accurate as CT in assessing most benign mediastinal pathology. The former study can easily differentiate atherosclerotic vessels or aneurysms from enlarged lymph nodes or masses, frequently obviating a more invasive study. It is especially efficacious in evaluating patients with cystic lesions, especially those with complex cysts not clearly of water density. In the hilum, MR can differentiate prominent hilar vessels from adenopathy or masses as reliably as CT. Again, in patients with renal failure or those who have documented allergies to iodinated contrast medium, MR should be the imaging procedure of choice to evaluate suspicious hila identified on plain chest radiographs. Magnetic resonance also can be used to differentiate central obstructing hilar tumors from peripheral collapsed lung. In certain cases, these findings may help determine resectability by demonstrating encasement of hilar and mediastinal vessels as well as the central airways. It should be anticipated that as technologic improvements continue to be made, MR will assume an increasingly important role in the imaging of thoracic disease

Computed tomographic (CT) and chest radiographic findings were retrospectively correlated with those found at fiberoptic bronchoscopy (FOB) in 58 patients presenting with hemoptysis. Abnormalities involving the airways were depicted by CT in a total of 28 cases (48%). In 18 of these (31% of the total group of 58), focal abnormalities involving the central airways were identified (17 were subsequently proved to be malignant) and in 10 (17% of the total), CT showed bronchiectasis. Focal airway abnormality was shown by FOB in 18 cases (31%); all of these were depicted with CT. Malignancy was diagnosed in 24 patients, including three in whom results of FOB were normal but malignant cells were identified at transbronchial biopsy. CT abnormalities were identified in all cases of malignancy. In 10 of 21 cases (48%) of non-small cell lung cancer, CT allowed definitive staging by documenting either direct mediastinal invasion and/or metastatic disease, while FOB allowed definitive staging in only three cases. CT studies provided no false-negative results. It is concluded that when carefully performed, CT may be an effective modality for evaluating patients presenting with hemoptysis

We studied 8 adult patients with variable symptoms of cough, dyspnea, stridor, wheezing, or hemoptysis. Fiberoptic bronchoscopy in all showed complete or nearly complete endobronchial obstruction of a main-stem bronchus by neoplasm with a mean bronchial diameter of 1.9 mm +/- 1.6 mm (mean +/- standard deviation). In 4 patients, a lobar bronchus was also completely obstructed. No mass was visible on chest radiographs of any patient; however, computed tomography in each showed main-stem endobronchial obstruction, lobar obstruction (4 instances in 3 patients), and in 6 patients hypoperfusion of the involved lung. Computed tomographic scan showed additional abnormalities that were unsuspected on viewing chest radiographs or at bronchoscopy, including mediastinal adenopathy in 3 patients and an extraluminal tumor component in 4. After therapy with Nd-YAG laser, main-stem airway diameter increased to a mean of 9.6 mm +/- 1.0 mm (P less than .05) and pulmonary functions improved. Results suggest the complementary role of computed tomography and fiberoptic bronchoscopy in the detection and laser-treatment planning of chest radiographically occult severe neoplastic obstruction of the main-stem bronchus.

Magnetic resonance (MR) images (0.5 and 1.5 T) and thin section CT scans were obtained in 17 cadaveric lungs (11 fixed, 6 both pre and post fixation). Standard T1-weighted spin echo (SE) sequences were used for all lungs. In six lungs, additional gradient-refocused echo (GRE) sequences were also obtained. The MR images and CT scans were compared to corresponding gross and microscopic pathologic sections. In all cases, MR SE sequences proved comparable to CT for delineation of normal anatomic structures as well as a range of pathologic conditions, including both air space and interstitial disease. Although image quality was markedly degraded on GRE compared to SE images, they did permit visualization of pulmonary vasculature and focal pathology

Primary malignant tumors of the pulmonary arteries occur infrequently and diagnosis is often delayed since symptoms are nonspecific. We present a case of pulmonary artery sarcoma and its interesting magnetic resonance findings