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Multiplanar and Three-Dimensional Imaging of the Central Airways with Multidetector CT

¹ Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Ave., Boston, MA 02215.
² Department of Pulmonary Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215.

Received December 26, 2001; accepted after revision February 11, 2002.

 
Presented in part at the annual meeting of the American Roentgen Ray Society, Seattle, April—May 2001.

Address correspondence to P.M. Boiselle.

Introduction

Top Introduction Traditional Axial CT Images Multidetector CT Images Reconstruction and Reformation... References

 
The advent of multidetector CT has revolutionized imaging of the airways and other thoracic structures [1,2,3,4,5]. In comparison to single-detector helical CT scanners, multidetector scanners not only provide faster speed, greater coverage, and improved spatial resolution, but also have the unique ability to create images of thick and thin collimation from the same data set [1,2,3,4,5].

One of the greatest benefits of this new technology is the improved quality of two-dimensional (2D) multiplanar and three-dimensional (3D) reconstruction images [3,4,5,6,7]. These images break away from the confines of the traditional axial imaging plane and have the potential to facilitate the assessment of a variety of airway disorders.

The purpose of this article is to familiarize radiologists with the basic principles of multiplanar and 3D images and to describe the evolving role of these methods in the assessment of central airway disorders.

Traditional Axial CT Images

Top Introduction Traditional Axial CT Images Multidetector CT Images Reconstruction and Reformation... References

 
Although routine axial CT images suffice for evaluating many airway abnormalities, several limitations are associated with axial images: limited ability to detect subtle airway stenoses; underestimation of the craniocaudal extent of disease; difficulty displaying complex 3D relationships of the airways; and inadequate representation of the airways that are oriented obliquely to the axial plane [6, 8,9,10,11] (Figs. 1A,1B,1C and 2A,2B,2C,2D,2E). Accurate identification, characterization, and measurement of airways diseases are of paramount importance for assigning the appropriate diagnosis and planning surgical and bronchoscopic procedures. Thus, the limitations of axial images have important implications in the assessment of patients with certain airways disorders such as airway stenoses and complex airway abnormalities.

View larger version (115K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 1A. —Axial, multiplanar, and three-dimensional (3D) CT images of central airways in 57-year-old man with non—small cell lung cancer and bronchoscopically proven airway invasion. Axial contrast-enhanced CT image obtained at level of aorticopulmonary window shows large nodal mass (N) compressing carina. Origin of right mainstem bronchus (arrow) is severely narrowed but is difficult to fully assess because of its oblique orientation with respect to axial plane.

View larger version (85K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 1B. —Axial, multiplanar, and three-dimensional (3D) CT images of central airways in 57-year-old man with non—small cell lung cancer and bronchoscopically proven airway invasion. Three-dimensional external-rendered CT image of airway shows irregular deformity of distal trachea and carina and severe narrowing of proximal right mainstem bronchus (arrow) with distal patency. Compared with axial images, such as A, 3D perspective provides more accurate assessment of overall extent of airway involvement.

View larger version (77K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 1C. —Axial, multiplanar, and three-dimensional (3D) CT images of central airways in 57-year-old man with non—small cell lung cancer and bronchoscopically proven airway invasion. Coronal multiplanar volume reformation CT image complements findings from 3D image (B) by showing relationship of large nodal mass (N) to airway.

View larger version (103K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2A. —Axial and three-dimensional (3D) images of central airways in 46-year-old woman with left mainstem bronchial stenosis resulting from prior tuberculosis infection. Craniocaudal extent and severity of stenosis were underestimated on axial CT images (A-D) but were accurately identified on basis of 3D reconstruction (E). Axial CT image obtained at level of carina shows subtle minimal wall thickening at origin of left mainstem bronchus (arrow).

View larger version (103K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2B. —Axial and three-dimensional (3D) images of central airways in 46-year-old woman with left mainstem bronchial stenosis resulting from prior tuberculosis infection. Craniocaudal extent and severity of stenosis were underestimated on axial CT images (A-D) but were accurately identified on basis of 3D reconstruction (E). Axial CT image obtained at slightly lower level than A shows subtle asymmetry in size of left mainstem bronchus (L) compared with right (R).

View larger version (109K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2C. —Axial and three-dimensional (3D) images of central airways in 46-year-old woman with left mainstem bronchial stenosis resulting from prior tuberculosis infection. Craniocaudal extent and severity of stenosis were underestimated on axial CT images (A-D) but were accurately identified on basis of 3D reconstruction (E). Axial CT image obtained at slightly lower level than B shows thickening of anterior wall of left mainstem bronchus (arrow). Calcified subcarinal lymph node is incidentally noted.

View larger version (80K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2D. —Axial and three-dimensional (3D) images of central airways in 46-year-old woman with left mainstem bronchial stenosis resulting from prior tuberculosis infection. Craniocaudal extent and severity of stenosis were underestimated on axial CT images (A-D) but were accurately identified on basis of 3D reconstruction (E). Axial CT image obtained at slightly lower level than C shows further extension of bronchial wall thickening (arrow).

View larger version (166K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2E. —Axial and three-dimensional (3D) images of central airways in 46-year-old woman with left mainstem bronchial stenosis resulting from prior tuberculosis infection. Craniocaudal extent and severity of stenosis were underestimated on axial CT images (A-D) but were accurately identified on basis of 3D reconstruction (E). Three-dimensional image of air-ways shows long segment of stenosis of left mainstem bronchus (arrows). Severity and length of stenosis correlated with findings at conventional bronchoscopy.

Multidetector CT Images

Top Introduction Traditional Axial CT Images Multidetector CT Images Reconstruction and Reformation... References

 
The creation of additional 2D multiplanar and 3D reconstruction images from the original axial CT data set can help overcome the limitations of axial images by providing a more anatomically meaningful display of complex structures such as the airways [6, 8,9,10,11] (Figs. 1B, 1C, and 2E). The visual accessibility of these images also offers other benefits: improved diagnostic confidence of an interpretation; improved planning for bronchoscopy and surgery; and enhanced communication among radiologists, clinicians, and patients.

Because multiplanar and 3D images transform the axial data into an anatomic display that is more familiar to clinicians and patients, this technology has the potential to improve the communication of radiologic findings. These images also enable the radiologist to review findings with referring clinicians in an efficient manner.

Two- and Three-Dimensional Images
Two-dimensional multiplanar and 3D reconstruction images do not actually create new information; rather, these images offer complementary ways of viewing the information present in the original CT data set. The axial images remain an important point of reference for optimal interpretation and also aid in the recognition of artifacts (e.g., from motion or retained secretions) on 2D and 3D images. Moreover, the axial images provide a more comprehensive review of the entirety of the thorax, including the lung parenchyma and mediastinal structures. Thus, in addition to the reformatted and reconstructed images, the axial images should also be reviewed when interpreting a study.

Optimizing Multiplanar and Three-Dimensional Images
For the appearance of multiplanar and 3D images to be enhanced, the use of a narrow (2.5-3.0 mm) collimation and overlapping reconstruction intervals (50%) is recommended [3]. Our clinical experience with multidetector CT has been with one brand of CT scanner (LightSpeed QX/i; General Electric Medical Systems, Milwaukee, WI). For dedicated airway studies, we use a 2.5-mm collimation, 1.25-mm reconstruction interval, and a pitch of 6:1.

Although airway studies should ideally be prospectively planned and tailored to the area of interest, an advantage of multidetector CT is its ability to allow slice thickness to be changed retrospectively, thus enabling one to obtain high-quality reconstruction images from routine CT studies. This feature is particularly helpful in daily practice because it allows patients undergoing routine imaging to potentially benefit from the creation of 2D multiplanar and 3D reconstructions without the need for additional acquisitions.

IV contrast material is not routinely administered but is recommended for patients with a suspected paratracheal abnormality such as enlarged lymph nodes or a thyroid mass. Airway imaging is routinely performed at end-inspiration during a single breath-hold. State-of-the-art helical scanners allow the entire central airways to be imaged in less than 5 sec. The speed of the examination is particularly important when imaging patients with airway disorders because many of these patients cannot tolerate the significantly longer breath-hold time required by single-detector CT scanners. Short scanning time is also an advantage for imaging during dynamic breathing or at end-expiration in patients with suspected tracheomalacia, a condition characterized by excessive collapse of the airway during expiration. We perform these additional sequences using a low-dose technique (i.e., 40 mA) to decrease radiation exposure [12].

Reconstruction and Reformation Methods

Top Introduction Traditional Axial CT Images Multidetector CT Images Reconstruction and Reformation... References

 
Three-Dimensional Reconstruction Methods
Three-dimensional reconstructions require the transfer of data to a separate workstation that allows the interactive display of 3D images in real time. These workstations are becoming increasingly commonplace in a variety of inpatient and outpatient radiology department settings. Our experience is with two workstations (Advantage, General Electric Medical Systems; Vitrea, Vital Images, Plymouth, MN).

Because volume-rendering techniques allow all the information initially acquired to be used in the final reconstruction, these methods are preferable to other techniques such as shaded-surface display, in which a large amount of data is lost in the final reconstruction [3, 6]. Most commercially available workstations provide a menu of options composed of various preset reconstruction algorithms, including dedicated airway techniques. The use of clip-editing planes (also referred to as trimming or extraction functions) precludes the need for tracing regions of interest and allows one to create 3D images in an efficient manner [3]. In this way, a trained technologist or radiologist can complete a series of reconstructions in less than 10 min.

Two basic methods of 3D imaging—external rendering and internal rendering—are available [6, 8,9,10,11]. Of these two methods, external rendering has had the greater clinical impact on airway imaging to date. Three-dimensional external rendering of the airways, also referred to as CT tracheobronchography, depicts the external surface of an airway and its relationship to adjacent structures [8, 9]. This method has been shown to help illustrate complex airway abnormalities such as congenital airway abnormalities (Fig. 3) and to improve the detection of subtle airway stenoses [8, 9] (Fig. 4). For example, in a study by Remy-Jardin et al. [8] in which axial and 3D-rendered images were obtained in 47 patients with benign tracheobronchial stenoses, 3D images provided supplemental information in one third of the patients by enabling a more precise evaluation of the shape, length, and degree of airway stenoses. In some of the patients, 3D rendering enabled the radiologist to identify mild stenoses that were not clearly depicted on axial images. In the same study, these authors assessed the role of 3D external rendering of the airway in 15 patients with a variety of complex tracheobronchial deformities and found that 3D images provided relevant supplemental information in more than half of the patients and corrected interpretive errors of axial images in approximately 10% of the patients.

View larger version (151K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 3. —Anomalous origin of right upper lobe segmental bronchi from right mainstem bronchus in 7-year-old girl with recurrent respiratory infections. Prior single-detector CT scan (not shown) was nondiagnostic because of respiratory motion. Multidetector CT scan was obtained in 4 sec and provided information that changed preoperative plan from lobectomy to segmentectomy. External three-dimensional volume-rendered image shows anomalous segmental bronchi (apical bronchus = 1, anterior bronchus = 2, posterior bronchus = 3) originate directly from right mainstem bronchus rather than from traditional right upper lobe bronchus. Severe bronchiectasis (arrows) in anterior segment can also be seen as well as mosaic pattern of lung attenuation. R = right, S = superior.

View larger version (92K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 4. —Idiopathic subglottic stenosis in 57-year-old woman. Three-dimensional (3D) external volume-rendered CT image of airway reveals focal subglottic stenosis (arrows). Airway stenoses are often more clearly depicted on 3D images than on axial images.

We now perform 3D external renderings routinely for suspected stenoses and complex airway abnormalities and find that these images provide important complementary information to axial images in most cases. In addition, we find that 3D external-rendered images aid in the assessment of patients with extrinsic compression of the airway from a variety of causes (Fig. 5A). In such cases, 3D images clearly depict the craniocaudal extent of the airway narrowing and the relationship of the involved airway to the adjacent structures.

View larger version (140K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 5A. —Extrinsic tracheal compression caused by thyroid goiter in 48-year-old woman. Three-dimensional external-rendered CT image of trachea shows smoothly marginated narrowing above level of thoracic inlet. To emphasize relationship of airway and skeletal landmarks of thoracic inlet, we chose reconstruction algorithm that extracted thyroid gland.

Internal rendering, also referred to as virtual bronchoscopy, combines helical CT data and virtual reality computing techniques to allow the viewer to navigate through the internal lumen of the airways in a similar fashion to conventional bronchoscopy [13,14,15,16,17,18,19,20,21]. This method produces images that closely correlate with conventional bronchoscopic images (Figs. 5C and 5D). Although the images are visually striking (Fig. 6), the precise role of this emerging technique has yet to be established. Thus, this method is still primarily considered an investigational tool [6]. Potential applications of virtual bronchoscopy include screening for endobronchial neoplasms, evaluating airway stenoses [18, 20], and guiding transbronchial needle aspiration procedures [16, 21].

View larger version (156K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 5C. —Extrinsic tracheal compression caused by thyroid goiter in 48-year-old woman. Three-dimensional internal-rendered CT image of trachea obtained at level of thyroid gland shows symmetric narrowing caused by extrinsic compression.

View larger version (98K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 5D. —Extrinsic tracheal compression caused by thyroid goiter in 48-year-old woman. Conventional bronchoscopic image of trachea obtained at same level as B shows similar degree of symmetric narrowing of trachea at level of thyroid gland.

View larger version (126K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 6. —Postoperative granulation polyp causing airway compromise in 24-year-old man who had previously undergone tracheal surgery. Virtual bronchoscopic image shows large anterior polyp projecting into tracheal lumen. Diagnosis of granulation polyp was made at bronchoscopic biopsy.

Despite the theoretic appeal of virtual bronchoscopy as a complementary tool to low-dose lung cancer screening with helical CT, this method is currently limited by a relatively high false-positive rate (Fig. 7A,7B) and its inability to detect early endobronchial neoplasms [22,23,24]. Future advances are necessary before this method can be effectively used as a screening tool.

View larger version (123K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 7A. —False-positive virtual bronchoscopic finding in 55-year-old man. Virtual bronchoscopic image obtained looking down trachea toward carina reveals focal polypoid lesion (arrow) along posterior wall of trachea.

View larger version (91K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 7B. —False-positive virtual bronchoscopic finding in 55-year-old man. Axial CT image obtained at same level as A using lung window settings shows dependent airway opacity with several gas bubbles (arrows), which is characteristic appearance of retained secretions.

A more practical indication for virtual bronchoscopy is the evaluation of the airways distal to a high-grade stenosis, beyond which a conventional bronchoscope cannot pass (Fig. 8A,8B,8C,8D,8E). In their study of 20 patients with airway stenosis, all of whom had cancer, Fleiter et al. [20] assessed virtual and conventional bronchoscopy and found that virtual bronchoscopy offered the advantage of viewing the airway beyond the site of stenosis in five patients (25%) in whom the bronchoscope could not pass through the lesion. Virtual bronchoscopy also offers the potential benefit of viewing a stenosis or obstructing endobronchial lesion from a distal perspective. In our practice, we occasionally find virtual bronchoscopy helpful for this purpose.

View larger version (73K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 8A. —Virtual bronchoscopic assessment of bronchial anastomosis stenosis and distal airways in 56-year-old man who had undergone right lung transplantation for emphysema. Three-dimensional external-rendered CT image of airway shows focal narrowing of airway (arrows) at site of bronchial anastomosis.

View larger version (93K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 8B. —Virtual bronchoscopic assessment of bronchial anastomosis stenosis and distal airways in 56-year-old man who had undergone right lung transplantation for emphysema. Virtual bronchoscopic image obtained at level of carina shows severe stenosis (arrows) at anastomosis site and normal appearance of left mainstem bronchus.

View larger version (114K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 8C. —Virtual bronchoscopic assessment of bronchial anastomosis stenosis and distal airways in 56-year-old man who had undergone right lung transplantation for emphysema. Virtual bronchoscopic image obtained at slightly lower level than B, looking down right mainstem bronchus, shows severe stenosis (arrows). Image has been slightly rotated to offer perspective similar to conventional bronchoscopic image (D). R = right, P = posterior.

View larger version (121K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 8D. —Virtual bronchoscopic assessment of bronchial anastomosis stenosis and distal airways in 56-year-old man who had undergone right lung transplantation for emphysema. Conventional bronchoscopic image obtained at same level as B shows tight stenosis (arrow) at anastomosis site, beyond which bronchoscope could not pass.

View larger version (95K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 8E. —Virtual bronchoscopic assessment of bronchial anastomosis stenosis and distal airways in 56-year-old man who had undergone right lung transplantation for emphysema. Virtual bronchoscopic image obtained distal to site of stenosis shows normal appearance of airways in transplanted lung.

Although virtual bronchoscopy was initially touted as a method for guiding transbronchial needle aspiration procedures of lymph nodes, this application has been largely supplanted by CT fluoroscopy because CT fluoroscopy provides real-time rather than virtual guidance [25,26,27]. In settings where CT fluoroscopy is not available, however, virtual bronchoscopy may be useful for providing a "road map" to the pulmonologist. For example, in a pilot study by McAdams et al. [21], virtual guidance improved the yield of and reduced the time required for CT fluoroscopy. Researchers have suggested that future technologic advances will allow interactive, real-time virtual reality guidance of airway procedures such as bronchoscopy and surgery [11]. Thus, this technique will likely play a larger role in these settings in the future.

Two-Dimensional Multiplanar Reformation Methods
Two-dimensional reformation methods, which include multiplanar reformations and multiplanar volume reformations [6, 10], are the easiest reconstructions to generate and can be interactively performed in real time at the CT console or at a dedicated workstation. Multiplanar reformation images are 1-voxel-thick sections that can be displayed in the coronal and sagittal planes or in a curved fashion along the axis of an airway. Multiplanar volume reformation images comprise a thick slab of adjacent thin slices and represent a block of contiguous images (Fig. 9A,9B,9C). Multiplanar volume reformation images thus combine the spatial resolution of multiplanar reformation images with the anatomic display of thick slices [11]. In addition to being reconstructed in the sagittal, coronal, and curved oblique planes, multiplanar volume reformation images can be reconstructed along the axis of the carina to enhance the continuous display of the central airways using a rotational (i.e., "paddle-wheel") method [28] (Fig. 10).

View larger version (69K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 9A. —Extrinsic bronchial compression from bronchogenic cyst in 51-year-old woman with recurrent left lower lobe pneumonias. Curved oblique two-dimensional multiplanar volume reformation image obtained along axis of left airway shows narrowing of left lower lobe bronchus as a result of extrinsic compression by adjacent mass (red), which was proven to represent bronchogenic cyst at surgery.

View larger version (97K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 9B. —Extrinsic bronchial compression from bronchogenic cyst in 51-year-old woman with recurrent left lower lobe pneumonias. Conventional bronchoscopic image obtained at level of left lower lobe bronchus shows extrinsic compression from adjacent bulging cyst.

View larger version (158K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 9C. —Extrinsic bronchial compression from bronchogenic cyst in 51-year-old woman with recurrent left lower lobe pneumonias. Three-dimensional external-rendered CT image shows relationship of cyst (red) and bronchi from different perspective.

View larger version (113K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 10. —Rotational "paddle-wheel" reformation method of normal central airways in 57-year-old man. Paddle-wheel multiplanar volume reformation image shows central airways in continuous display on single image. Minimum-intensity-projection algorithm, which highlights minimum-density voxels such as air-filled structures, was used to enhance visibility of airways in lung parenchyma. Also note evidence of emphysema.

Two-dimensional reformation images are helpful in the assessment of airway stenosis, endobronchial stents, and tracheomalacia [6, 11, 29,30,31]. For assessment of patients with tracheomalacia, paired end-inspiratory and end-expiratory sagittal 2D images along the axis of the trachea are helpful for displaying the craniocaudal extent of excessive tracheal collapse during expiration (Fig. 11A,11B).

View larger version (124K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 11A. —Tracheomalacia in 36-year-old woman with dyspnea and cough. Sagittal multiplanar volume reformation image obtained at end-inspiration shows normal caliber (arrows) of trachea (T). Air-filled structure posterior to trachea represents slightly distended esophagus.

View larger version (146K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 11B. —Tracheomalacia in 36-year-old woman with dyspnea and cough. Sagittal multiplanar volume reformation image obtained during dynamic breathing shows excessive collapse (arrows) of intrathoracic trachea (T), consistent with tracheomalacia, which was confirmed at conventional bronchoscopy. Grainy appearance of image reflects use of low-dose technique (40 mA).

With regard to the assessment of airway stenoses, multiplanar volume reformation methods aid in the detection of mild stenoses (Fig. 12), improve the accuracy of determining the length of stenoses, and aid in the identification of horizontal webs [6, 30,31,32]. Review of multiplanar volume-reformatted images has been shown to aid in the planning of stent placement or surgery [32]. In addition, these images provide an accurate measure to follow up patients who have undergone airway procedures [32]. The continuous display of stents provided by multiplanar volume-reformatted images also aids the identification of complications such as stent migration and fracture.

View larger version (60K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 12. —Airway obstruction and stenosis caused by non—small cell lung cancer in 56-year-old woman. Coronal minimal-intensity-projection multiplanar volume reformation image shows complete obstruction of bronchus intermedius (thick arrow) and narrowing of left mainstem bronchus (thin arrows). Although bronchus intermedius obstruction was seen equally well with axial images, length and severity of left mainstem bronchus narrowing were underestimated on axial images (not shown).

We routinely perform 2D multiplanar volume-reformatted images for the assessment of tracheomalacia, airway stents, and airway stenoses. For the latter indication, we perform both multiplanar volume-reformatted and 3D images because we find that these images often provide complementary information (Figs. 1B, 1C, 5A, 5B, 9A, and 9C).

View larger version (114K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 5B. —Extrinsic tracheal compression caused by thyroid goiter in 48-year-old woman. Coronal multiplanar volume reformation image shows relationship of enlarged thyroid gland (red) to trachea.

In summary, multidetector CT has ushered in an exciting new era of central airways imaging. Multiplanar and 3D reconstruction images provide an important complementary method of viewing central airways disorders and offer the potential to improve diagnostic confidence and accuracy and enhance communication and planning for procedures. At present, we routinely obtain these images for the assessment of airway stenoses and webs, complex airways diseases, tracheomalacia, and stent placement. We anticipate that future advances in CT technology, data-processing, and image display will further expand the role of multiplanar and 3D reconstruction images in the assessment of a variety of disorders of the central airways.

Acknowledgments
 
We thank Michael Larson for assistance with photography, Donna Wolfe for editorial assistance, Ellen C. Boiselle for her thoughtful review of this manuscript, Dawn Weeks for technical assistance with CT reformation and reconstruction images, David Feller-Kopman for assistance with conventional bronchoscopic images, and Julianna Szymanczyk for administrative assistance.

References

Top Introduction Traditional Axial CT Images Multidetector CT Images Reconstruction and Reformation... References

 

1. Hu H, He HD, Foley WD, Fox SH. Four multidetector-row helical CT: image quality and volume coverage speed. Radiology 2000;215:55 -62[Abstract/Free Full Text]
2. Klingenbeck-Regn K, Schaller S, Flohr T, Ohnesorge B, Kopp AF, Baum U. Subsecond multi-slice computed tomography: basics and applications. Eur J Radiol 1999;31:110 -124[Medline]
3. Lawler LP, Fishman EK. Multi-detector row CT of thoracic disease with emphasis on 3D volume rendering and CT angiography. RadioGraphics 2001;21:1257 -1273[Abstract/Free Full Text]
4. Rydberg J, Buckwalter KA, Caldemeyer KS, et al. Multislice CT: scanning techniques and clinical applications. RadioGraphics 2000;20:1787 -1806[Abstract/Free Full Text]
5. Choi RJ, Boiselle PM. Multidetector helical computed tomography. In: Boiselle PM, White CS, eds. New techniques in thoracic imaging. New York: Marcel-Dekker, 2001:71 -90
6. Ravenel JG, McAdams HP, Remy-Jardin M, Remy J. Multidimensional imaging of the thorax: practical applications. J Thorac Imaging 2001;16:269 -281[Medline]
7. Fleischmann D, Rubin GD, Paik DS, et al. Stairstep artifacts with single versus multiple detector-row helical CT. Radiology 2000;216:185 -196[Abstract/Free Full Text]
8. Remy-Jardin M, Remy J, Artaud D, Fribourg M, Naili A. Tracheobronchial tree: assessment with volume rendering—technical aspects. Radiology 1998;208:393 -398[Abstract/Free Full Text]
9. Remy-Jardin M, Remy J, Artaud D, Fribourg M, Duhamel A. Volume rendering of the tracheobronchial tree: clinical evaluation of bronchographic images. Radiology 1998;208:761 -770[Abstract/Free Full Text]
10. Naidich DP, Gruden JF, McGuinness G, McCauley DI, Bhalla M. Volumetric (helical/spiral) CT (VCT) of the airways. J Thorac Imaging 1997;12:11 -28[Medline]
11. Salvolini L, Secchi EB, Costarelli L, De Nicola M. Clinical applications of 2D and 3D CT imaging of the airways: a review. Eur J Radiol 2000;34:9 -25[Medline]
12. Choi YW, McAdams HP, Jeon SC, Park C, Lee S, Hahm C. Low-dose spiral CT: application to three-dimensional imaging of central airways. (abstr) Radiology 2000;217(P):385[Abstract/Free Full Text]
13. Higgins WE, Ramaswamy K, Swift RD, McLennan G, Hoffman EA. Virtual bronchoscopy for three-dimensional pulmonary image assessment: state of the art and future needs. RadioGraphics 1998;18:761 -778[Abstract]
14. Haponik EF, Aquino SL, Vining DJ. Virtual bronchoscopy. Clin Chest Med 1999;20:201 -217[Medline]
15. Vining DJ, Liu K, Choplin RH, Haponik EF. Virtual bronchoscopy: relationships of virtual reality endobronchial simulations to actual bronchoscopic findings. Chest 1996;109:549 -553[Abstract/Free Full Text]
16. Boiselle PM, Patz EF Jr, Vining DJ, Weissleder R, Shepard JOA, McLoud TC. Imaging of mediastinal lymph nodes: CT, MR, and FDG PET. RadioGraphics 1998;18:1061 -1069[Abstract]
17. Rodenwaldt J, Kopka L, Roedel R, Margas A, Grabbe E. 3D virtual endoscopy of the upper airway: optimization of the scan parameters in a cadaver phantom and clinical assessment. J Comput Assist Tomogr 1997;21:405 -411[Medline]
18. Kauczor HU, Wolcke B, Fischer B, Mildenberger P, Lorenz J, Thelen M. Three-dimensional helical CT of the tracheobronchial tree: evaluation of imaging protocols and assessment of suspect stenoses with bronchoscopic correlation. AJR 1996;167:419 -424[Abstract/Free Full Text]
19. Hopper KD, Iyriboz AT, Wise SW, Neuman JD, Mauger DT, Kasales CJ. Mucosal detail at CT virtual reality: surface versus volume rendering. Radiology 2000;214:517 -522[Abstract/Free Full Text]
20. Fleiter T, Merkle EM, Aschoff AJ, et al. Comparison of real-time virtual and fiberoptic bronchoscopy in patients with bronchial carcinoma: opportunities and limitations. AJR 1997;169:1591 -1595[Abstract/Free Full Text]
21. McAdams HP, Goodman PC, Kussin P. Virtual bronchoscopy for directing transbronchial needle aspiration of hilar and mediastinal lymph nodes: a pilot study. AJR 1998;170:1361 -1364[Abstract/Free Full Text]
22. Summers RM, Selbie WS, Malley JD, et al. Polypoid lesions of airways: early experience with computer-assisted detection by using virtual bronchoscopy and surface curvature. Radiology 1998;208:331 -337[Abstract/Free Full Text]
23. Summers RM, Shaw DJ, Shelhamer JH. CT virtual bronchoscopy of simulated endobronchial lesions: effect of scanning, reconstruction, and display settings and potential pitfalls. AJR 1998;170:947 -950[Free Full Text]
24. Boiselle PM, Ernst A, Karp DD. Lung cancer detection in the 21st century: potential contributions and challenges of emerging technologies. AJR 2000;175:1215 -1221[Free Full Text]
25. Goldberg SN, Raptopoulos V, Boiselle PM, Edinburgh KJ, Ernst A. Mediastinal lymphadenopathy: diagnostic yield of transbronchial mediastinal lymph node biopsy with CT fluoroscopic guidance—initial experience. Radiology 2000;216:764 -767[Abstract/Free Full Text]
26. Garpestad E, Goldberg S, Herth F, et al. CT fluoroscopy guidance for transbronchial needle aspiration: an experience in 35 patients. Chest 2001;119:329 -332[Abstract/Free Full Text]
27. White CS, Weiner EA, Patel P, Britt EJ. Transbronchial needle aspiration: guidance with CT fluoroscopy. Chest 2000;118:1630 -1638[Abstract/Free Full Text]
28. Simon M, Boiselle PM, Choi JR, Rosen MP, Reynolds K, Raptopoulos V. Paddle-wheel CT display of pulmonary arteries and other lung structures: a new imaging approach. AJR 2001;177:195 -198[Free Full Text]
29. McAdams HP, Palmer SM, Erasmus JJ, et al. Bronchial anastomotic complications in lung transplant recipients: virtual bronchoscopy for noninvasive assessment. Radiology 1998;209:689 -695[Abstract/Free Full Text]
30. Quint LE, Whyte RI, Kazerooni EA, et al. Stenosis of the central airways: evaluation by using helical CT with multiplanar reconstructions. Radiology 1995;194:871 -877[Abstract/Free Full Text]
31. Remy-Jardin M, Remy J, Deschildre F, Artaud D, Ramon P, Edme JL. Obstructive lesions of the central airways: evaluation by using spiral CT with multiplanar and three-dimensional reformations. Eur Radiol 1996;6:807 -816[Medline]
32. LoCicero J, Costello P, Campos CT, et al. Spiral CT with multiplanar and 3D reconstructions accurately predicts tracheobronchial pathology. Ann Thorac Surg 1996;62:811 -817[Abstract/Free Full Text]

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