Principles of computed tomography of the chest
- Paul Stark, MD
Paul Stark, MD
- Professor of Radiology
- University of California San Diego
- Section Editor
- Nestor L Muller, MD, PhD
Nestor L Muller, MD, PhD
- Section Editor — Pulmonary Imaging
- Professor of Radiology
- University of British Columbia
- Deputy Editors
- Geraldine Finlay, MD
Geraldine Finlay, MD
- Deputy Editor — Pulmonary, Critical Care, and Sleep Medicine
- Associate Professor
- Tufts University School of Medicine
- Susanna I Lee, MD, PhD
Susanna I Lee, MD, PhD
- Deputy Editor — Radiology
- Associate Professor of Radiology
- Harvard Medical School
- Massachusetts General Hospital
Computed tomography (CT) is an imaging technique that has revolutionized medical imaging. It is widely available, fast, and provides a detailed view of the internal organs and structures.
The two major types of CT are helical CT and conventional, axial, step-and-shoot CT. Helical CT is most prevalent, but conventional step-and-shoot, axial technique is used for high-resolution CT scanning of the lungs, coronary artery calcium scoring, and prospective ECG-gated coronary CT angiography.
The technical aspects of CT are reviewed here. The role of CT in various clinical situations is described separately. (See "High resolution computed tomography of the lungs" and "Computed tomographic and positron emission tomographic scanning of pulmonary nodules" and "Imaging of non-small cell lung cancer" and "Computed tomography of the hepatobiliary tract" and "Noninvasive coronary imaging with cardiac computed tomography and cardiovascular magnetic resonance".)
The principal components of a CT scanner are the x-ray tube and a diametrically opposed array of detectors :
●The x-ray tube rotates around the patient and generates an x-ray beam (figure 1). The gantry motion is helical during helical CT and circular during conventional, axial, step-and-shoot CT.
- McCollough CH, Morin RL. The technical design and performance of ultrafast computed tomography. Radiol Clin North Am 1994; 32:521.
- Brink JA, Heiken JP, Wang G, et al. Helical CT: principles and technical considerations. Radiographics 1994; 14:887.
- Flohr TG, Schaller S, Stierstorfer K, et al. Multi-detector row CT systems and image-reconstruction techniques. Radiology 2005; 235:756.
- Kalra MK, Maher MM, D'Souza R, Saini S. Multidetector computed tomography technology: current status and emerging developments. J Comput Assist Tomogr 2004; 28 Suppl 1:S2.
- Prokop M. General principles of MDCT. Eur J Radiol 2003; 45 Suppl 1:S4.
- Rubin GD. 3-D imaging with MDCT. Eur J Radiol 2003; 45 Suppl 1:S37.
- Rydberg J, Buckwalter KA, Caldemeyer KS, et al. Multisection CT: scanning techniques and clinical applications. Radiographics 2000; 20:1787.
- Slavin GS, Bluemke DA. Spatial and temporal resolution in cardiovascular MR imaging: review and recommendations. Radiology 2005; 234:330.
- Ameli-Renani S, Rahman F, Nair A, et al. Dual-energy CT for imaging of pulmonary hypertension: challenges and opportunities. Radiographics 2014; 34:1769.
- Delesalle MA, Pontana F, Duhamel A, et al. Spectral optimization of chest CT angiography with reduced iodine load: experience in 80 patients evaluated with dual-source, dual-energy CT. Radiology 2013; 267:256.
- Zeman RK, Fox SH, Silverman PM, et al. Helical (spiral) CT of the abdomen. AJR Am J Roentgenol 1993; 160:719.
- Kalender WA, Seissler W, Klotz E, Vock P. Spiral volumetric CT with single-breath-hold technique, continuous transport, and continuous scanner rotation. Radiology 1990; 176:181.
- Crawford CR, King KF. Computed tomography scanning with simultaneous patient translation. Med Phys 1990; 17:967.
- Vock P, Soucek M, Daepp M, Kalender WA. Lung: spiral volumetric CT with single-breath-hold technique. Radiology 1990; 176:864.
- Heiken JP, Brink JA, Vannier MW. Spiral (helical) CT. Radiology 1993; 189:647.
- Mountain CF. A new international staging system for lung cancer. Chest 1986; 89:225S.
- Brink JA, Heiken JP, Balfe DM, et al. Spiral CT: decreased spatial resolution in vivo due to broadening of section-sensitivity profile. Radiology 1992; 185:469.
- Wang G, Vannier MW. Longitudinal resolution in volumetric x-ray computerized tomography--analytical comparison between conventional and helical computerized tomography. Med Phys 1994; 21:429.
- Foley WD, Oneson SR. Helical CT: clinical performance and imaging strategies. Radiographics 1994; 14:894.
- Kasales CJ, Hopper KD, Ariola DN, et al. Reconstructed helical CT scans: improvement in z-axis resolution compared with overlapped and nonoverlapped conventional CT scans. AJR Am J Roentgenol 1995; 164:1281.
- Tomiak MM, Foley WD, Jacobson DR. Variable-mode helical CT: imaging protocols. AJR Am J Roentgenol 1995; 164:1525.
- Johkoh T, Honda O, Mihara N, et al. Pitfalls in the interpretation of multidetector-row helical CT images at window width and level setting for lung parenchyma. Radiat Med 2001; 19:181.
- Bae KT. Intravenous contrast medium administration and scan timing at CT: considerations and approaches. Radiology 2010; 256:32.
- Rubin GD, Dake MD, Napel SA, et al. Three-dimensional spiral CT angiography of the abdomen: initial clinical experience. Radiology 1993; 186:147.
- Rubin, GD, Costello, P. Three-dimensional spiral CT angiography. In: Radiology: Diagnosis, Imaging, and Intervention, Taveras, JM, Ferrucci, JT (Eds), Lippincott, Philadelphia, PA, 1994; 152:1-15.
- Rubin GD. Three-dimensional helical CT angiography. Radiographics 1994; 14:905.
- Napel S, Marks MP, Rubin GD, et al. CT angiography with spiral CT and maximum intensity projection. Radiology 1992; 185:607.
- Napel S, Rubin GD, Jeffrey RB Jr. STS-MIP: a new reconstruction technique for CT of the chest. J Comput Assist Tomogr 1993; 17:832.
- Magnusson M, Lenz R, Danielsson PE. Evaluation of methods for shaded surface display of CT volumes. Comput Med Imaging Graph 1991; 15:247.
- Rubin GD, Beaulieu CF, Argiro V, et al. Perspective volume rendering of CT and MR images: applications for endoscopic imaging. Radiology 1996; 199:321.
- Napoli A, Fleischmann D, Chan FP, et al. Computed tomography angiography: state-of-the-art imaging using multidetector-row technology. J Comput Assist Tomogr 2004; 28 Suppl 1:S32.
- Brink JA. Contrast optimization and scan timing for single and multidetector-row computed tomography. J Comput Assist Tomogr 2003; 27 Suppl 1:S3.
- Achenbach S, Ulzheimer S, Baum U, et al. Noninvasive coronary angiography by retrospectively ECG-gated multislice spiral CT. Circulation 2000; 102:2823.
- Saini S. Multi-detector row CT: principles and practice for abdominal applications. Radiology 2004; 233:323.
- Cody DD, Mahesh M. AAPM/RSNA physics tutorial for residents: Technologic advances in multidetector CT with a focus on cardiac imaging. Radiographics 2007; 27:1829.
- Entrikin DW. True high-definition in cardiac imaging will require 4 dimensions of technologic innovation. J Cardiovasc Comput Tomogr 2009; 3:252.
- Berland LL, Smith JK. Multidetector-array CT: once again, technology creates new opportunities. Radiology 1998; 209:327.
- Weg N, Scheer MR, Gabor MP. Liver lesions: improved detection with dual-detector-array CT and routine 2.5-mm thin collimation. Radiology 1998; 209:417.
- Rubin GD, Kalra MK. MDCT Angiography of the thoracic aorta. In: MDCT from protocols to practice, Kalra MK, Saini S, Rubin GD (Eds), Springer Verlag, 2006. p.225.
- Schoepf UJ, Holzknecht N, Helmberger TK, et al. Subsegmental pulmonary emboli: improved detection with thin-collimation multi-detector row spiral CT. Radiology 2002; 222:483.
- Ahn MI, Gleeson TG, Chan IH, et al. Perifissural nodules seen at CT screening for lung cancer. Radiology 2010; 254:949.
- Godoy MC, Naidich DP. Subsolid pulmonary nodules and the spectrum of peripheral adenocarcinomas of the lung: recommended interim guidelines for assessment and management. Radiology 2009; 253:606.
- Thompson BH, Stanford W. Evaluation of cardiac function with ultrafast computed tomography. Radiol Clin North Am 1994; 32:537.
- Galvin JR, Gingrich RD, Hoffman E, et al. Ultrafast computed tomography of the chest. Radiol Clin North Am 1994; 32:775.
- Detrano R, Guerci AD, Carr JJ, et al. Coronary calcium as a predictor of coronary events in four racial or ethnic groups. N Engl J Med 2008; 358:1336.
- Nickoloff EL, Lu ZF, Dutta AK, So JC. Radiation dose descriptors: BERT, COD, DAP, and other strange creatures. Radiographics 2008; 28:1439.
- Parry RA, Glaze SA, Archer BR. The AAPM/RSNA physics tutorial for residents. Typical patient radiation doses in diagnostic radiology. Radiographics 1999; 19:1289.
- Mettler FA Jr, Bhargavan M, Faulkner K, et al. Radiologic and nuclear medicine studies in the United States and worldwide: frequency, radiation dose, and comparison with other radiation sources--1950-2007. Radiology 2009; 253:520.
- Schauer DA, Linton OW. National Council on Radiation Protection and Measurements report shows substantial medical exposure increase. Radiology 2009; 253:293.
- Ehman EC, Yu L, Manduca A, et al. Methods for clinical evaluation of noise reduction techniques in abdominopelvic CT. Radiographics 2014; 34:849.
- Amis ES Jr, Butler PF, Applegate KE, et al. American College of Radiology white paper on radiation dose in medicine. J Am Coll Radiol 2007; 4:272.
- Mayo JR, Aldrich J, Muller NL, Fleischner Society. Radiation exposure at chest CT: a statement of the Fleischner Society. Radiology 2003; 228:15.
- Litmanovich DE, Tack DM, Shahrzad M, Bankier AA. Dose reduction in cardiothoracic CT: review of currently available methods. Radiographics 2014; 34:1469.
- GENERAL DESCRIPTION
- Duration of the helix
- Reconstruction interval
- Gantry rotation time
- BREATHING INSTRUCTIONS
- INTRAVENOUS CONTRAST
- DATA PROCESSING
- TWO-DIMENSIONAL AND THREE-DIMENSIONAL RENDERING
- CT ANGIOGRAPHY
- MULTISLICE HELICAL CT
- Technical parameters
- ELECTRON BEAM CT
- RADIATION DOSE
- SUMMARY AND RECOMMENDATIONS