Meenakshi Bhalla

Volumetric (helical / spiral) CT (VCT) of the airways

Volumetric computed tomography (VCT) represents an important improvement over conventional CT for assessing most airway abnormalities. Elimination of misregistration due to variations in respiration coupled with decreased motion artifacts and the ability to obtain routine overlapping sections allow a more confident estimation of the presence and extent of disease. Recently, attention has focused on newer reconstruction techniques including: multiplanar reconstructions (MPRs), including curved multiplanar reformations; multiplanar volume reconstructions (MPVRs) using ray projection techniques, such as maximum and minimum projection imaging; external rendering, or 3D-shaded surface displays; and, most recently, internal rendering or so-called “virtual bronchoscopy”. Given the often redundant nature of many of these methodologies determining indications for their use remains to be established, especially by comparison to axial imaging. The purpose of this article is to review these various reconstruction techniques and, based on current knowledge, place them in an appropriate clinical context.

Counting ribs on chest CT

We describe the anatomy of the costovertebral articulations along with a simple and reliable method of counting the ribs on chest CT.

Primary extraosseous pulmonary osteogenic sarcoma : CT findings

This is a report of a primary extraosseous osteogenic sarcoma of the lung. The patient presented with fever and productive cough. Chest radiography and CT showed a cavitary lesion with an air-fluid level. The lesion was treated as an abscess. Despite aggressive antibiotic therapy and drainage, the patient continued to deteriorate rapidly. At autopsy the lesion was found to be a primary extraosseous pulmonary osteogenic sarcoma.

Normal position of trachea and anterior junction line on CT.

Objective and Methods In unilateral diseases of the chest accompanied by either volume loss or expansion there is mediastinal shift and mediastinal “herniation‘’ of one lung into the opposite hemithorax. This may also be accompanied by changes in the size of the hemithoraces. Although early detection of these changes may be difficult on chest radiography, one can detect all these changes on CT with greater ease. Since the normal range of position of the mediastinal structures on CT and the symmetry of the hemithoraces have not been studied before, we conducted a prospective study of normal chest CT to define the range of position of the trachea and the anterior junction line, as well as the normal range of differences in the parasagittal diameters of the two hemithoraces. Results The trachea was

Radiographic Features Useful for Establishing Patient Identity from Improperly Labeled Portable Chest Radiographs

1.6 cm to the right and 0.7 cm to the left of midline; the anterior junction line was

Acute chest syndrome in sickle cell disease: CT evidence of microvascular occlusion.

1 cm to the right and 2 cm to the left. The hemithoraces were asymmetric in 84%, with the difference in the parasagittal diameters of the two hemithoraces

Lung hernia: radiographic features.

1.5 cm. Conclusion These data may help radiologists detect subtle mediastinal shifts and asymmetry in patients with unilateral pleural or pulmonary disease.

Chest CT in patients with scleroderma: prevalence of asymptomatic esophageal dilatation and mediastinal lymphadenopathy.

Radiologists in hospital practice often encounter radiographs that either bear no patient identification or are incorrectly labeled as those of a different patient. To avoid repeating these improperly labeled radiographs, and to establish correct patient identity, most radiologists compare these radiographs with previous radiographs of several patients. This happens most often with portable chest radiographs. To study the reliability of various surgical, pathologic, and anatomic features and to help establish a fast and accurate method of establishing the correct patient identity, we performed a retrospective study of 50 patients in the intensive care unit. The characteristic location and configuration of surgical material, fractures, and dense parenchymal/pleural scars with or without calcifications are extremely helpful in establishing patient identity. In the vast majority of patients who lack such characteristic surgical and pathologic features, the anatomic structures that are most reliable for identification purposes are, in order of decreasing reliability, the transverse processes of the first thoracic vertebrae and the adjoining tubercles of the first ribs, the spinous processes, and the scapular wings. We believe that this information will help radiologists to identify the right patient when radiographs are incorrectly labeled.