Medical Imaging : Essentials for Physicians.
Title:
Medical Imaging : Essentials for Physicians.
Author:
Wolbarst, Anthony B.
ISBN:
9781118480281
Personal Author:
Edition:
1st ed.
Physical Description:
1 online resource (435 pages)
Contents:
Medical Imaging: Essentials for Physicians -- Contents -- Preface -- Acknowledgments -- INTRODUCTION : Dr. Doe's Headaches An Imaging Case Study -- Computed tomography -- Picture archiving and communication system -- T1, T2, and FLAIR MRI -- MR spectroscopy and a virtual biopsy -- Functional MRI -- Diffusion tensor MR imaging -- MR guided biopsy -- Pathology -- Positron emission tomography? -- Treatment and follow-up -- CHAPTER 1 Sketches of the Standard Imaging Modalities : Different Ways of Creating Visible Contrast Among Tissues -- "Roentgen has surely gone crazy!" -- Different imaging probes interact with different tissues in different ways and yield different kinds of medical information -- Twentieth-century (analog) radiography and fluoroscopy: contrast from differential attenuation of X-rays by tissues -- X-ray film of a cracked phalange -- Generating the beam at the anode of the X-ray tube -- Contrast from differential attenuation of the beam within the body -- Exposure of a screen-film image receptor -- Image intensifier-based fluoroscopy with a CCD/CMOS electronic optical camera -- Twenty-first century (digital) images and digital planar imaging: computer-based images and solid-state image receptors -- Digital images -- Computed tomography: three-dimensional mapping of X-ray attenuation by tissues -- Helical, multi-slice CT -- Nuclear medicine, including SPECT and PET: contrast from the differential uptake of a radiopharmaceutical by tissues -- Radiopharmaceutical = radionucleus + organ-specific agent -- Creating contrast through differential uptake of photon-generating radiopharmaceuticals -- SPECT and PET -- Diagnostic ultrasound: contrast from differences in tissue elasticity or density -- B-mode anatomic imaging -- Doppler imaging of blood flow.
Magnetic resonance imaging: mapping the spatial distribution of spin-relaxation times of hydrogen nuclei in tissue water and lipids -- Spin-relaxation times of protons in water and lipids in a strong magnetic field -- Mapping the spatial distribution of proton T1 and T2 -- Appendix: selection of imaging modalities to assist in medical diagnosis -- Cardiac versus non-cardiac chest pain -- Abdominal/pelvis imaging -- Head and neck imaging -- Musculoskeletal imaging -- Vascular imaging -- References -- CHAPTER 2 Image Quality and Dose : What Constitutes a "Good" Medical Image? -- A brief history of magnetism -- About those probes and their interactions with matter . . . -- Energy -- Electromagnetic waves -- Photons -- Atoms -- Molecules and fluorescent materials -- The image quality quartet: contrast, resolution, stochastic (random) noise, artifacts - and always dose -- Subject contrast -- Resolution -- Stochastic (random, statistical) noise and the signal-to-noise ratio -- Artifacts: non-stochastic noise -- Quality assurance -- Image quality and radiation safety programs -- Image QA -- Known medical benefits versus potential radiation risks -- Dose of ionizing radiation -- Possible radiation risks -- Radiation (and other) safety QA -- CHAPTER 3 Creating Subject Contrast in the Primary X-ray Image : Projection Maps of the Body from Differential Attenuation of X-rays by Tissues -- Creating a (nearly) uniform beam of penetrating X-rays -- Anatomy of an X-ray tube -- Less than 1% of the energy deposited in the target/anode becomes bremsstrahlung and characteristic X-ray radiation -- Heat -- Control of the X-ray exposure: the three technique factors -- Interaction of X-ray and gamma-ray photons with tissues or an image receptor -- The global picture -- Exponential attenuation of an ideal X-ray beam by an ideal medium -- The microscopic view.
The interaction of electromagnetic radiation with matter depends on the energy of the photons and on the makeup of the material -- Two principal mechanisms for the interaction of gamma- and X-ray photons with atomic electrons: photoelectric absorption and Compton scatter -- The rate of beam attenuation increases with density -- The photoelectric linear attenuation coefficient, μPA, depends on the chemical composition of the tissue or image receptor and on the effective energy of the beam -- the Compton coefficient, μCS, is virtually independent of both -- Why the rate of photoelectric absorption declines so rapidly with photon energy -- What a body does to the beam: subject contrast in the pattern of X-rays emerging from the patient -- Differential photoelectric absorption produces most of the subject contrast in the primary X-ray image -- Compton scatter mainly reduces subject contrast in the primary X-ray beam. . . -- . . . But a grid can remove much of the scatter radiation, at the price of more patient dose -- What the beam does to a body: dose and risk -- In tissues, all the dose is deposited by ejected high-energy photoelectrons and Compton electrons (but in a high-Z image receptor, only by photoelectrons) -- Selection of the kVp: the great contrast versus dose tradeoff -- CHAPTER 4 Twentieth-century (Analog) Radiography and Fluoroscopy : Capturing the X-ray Shadow with a Film Cassette or an Image Intensifier Tube plus Electronic Optical Camera Combination -- Recording the X-ray pattern emerging from the patient with a screen-film image receptor -- A fluoroscopic screen reduces patient dose but diminishes resolution -- The exposure and development of radiographic film -- Optical density of developed radiographic film and the characteristic curve.
Prime determinants/measures of image quality: contrast, resolution, random noise, artifacts, . . . and, always, patient dose -- Subject contrast, image-receptor contrast, and image contrast -- Resolution: causes of unsharpness -- Contrast and resolution together: the modulation transfer function -- Stochastic noise and lesion detection -- Deterministic noise and other artifacts -- Special requirements for mammography -- The dedicated mammography system: particularly high contrast and resolution are essential, along with very low dose -- QA and the Mammography Quality Standards Act -- Image intensifier-tube fluoroscopy: viewing in real time -- Analog fluoroscopy = X-ray tube + image intensifier tube + solid-state CCD or CMOS electronic optical camera -- Fluoroscopy QA -- Conclusion: bringing radiography and fluoroscopy into the twenty-first century with solid-state digital X-ray image receptors -- Reference -- CHAPTER 5 Radiation Dose and Radiogenic Risk : Ionization-Induced Damage to DNA can cause Stochastic, Deterministic, and Teratogenic Health Effects - And How To Protect Against Them -- Our exposure to ionizing radiation has doubled over the past few decades -- Radiation health effects are caused by damage to DNA -- Radiogenic damage to DNA -- Stochastic health effects: cancer may arise from mutations in a single cell -- Stochastic (probabilistic) radiogenic health effects -- The sievert (Sv) of equivalent dose: accounting also for stochastic biological risk -- The critically important linear no-threshold dose-risk assumption, and estimates of [Risk/Dose] -- Optimal dose for patient survival of both the disease and the diagnosis -- The effective dose (in Sv) is currently the least bad predictor of cancer risk S -- Representative doses for diagnostic studies -- Stochastic health effects in children.
Deterministic health effects at high doses: radiation killing of a large number of tissue cells -- Deterministic radiogenic health effects -- Teratogenic effects in the unborn -- Acute radiation syndrome -- The Four Quartets of radiation safety -- Personal actions -- Department activities -- Administrative structure: recommendations, laws, regulations, licensing, accreditation -- The philosophy of radiation protection -- References -- CHAPTER 6 Twenty-first Century (Digital) Imaging : Computer-Based Representation, Acquisition, Processing, Storage, Transmission, and Analysis of Images -- Digital computers -- A bit about bytes -- Hardware and architecture -- Digital acquisition and representation of an image -- A medical image comprises one million pixels, give or take a factor of ten: digitizing a radiograph -- Determinants of image quality: resolution, pixel size, matrix dimensions, and field of view -- Aliasing and the Nyquist theorem -- More determinants of image quality: gray scale and windowing -- Number of bytes per image: matrix dimensions and gray-scale depth -- Image compression -- Reconstruction -- Digital image processing: enhancing tissue contrast, SNR, edge sharpness, etc. -- Smoothing -- Sharpening -- Computer networks: PACS, RIS, and the Internet -- Image analysis and interpretation: computer-assisted detection -- Computer and computer-network security -- Liquid crystal displays and other digital displays -- The joy of digital -- CHAPTER 7 Digital Planar Imaging : Replacing Film and Image Intensifiers with Solid State, Electronic Image Receptors -- Digital planar imaging modalities -- Indirect detection with a fluorescent screen and a CCD -- Computed radiography -- Digital radiography with an active matrix flat panel imager -- Active matrix flat panel imager -- Indirect detection digital radiography.
Direct detection digital radiography.
Abstract:
Preface x Acknowledgments xiii Introduction: Dr. Doe's Headaches: An Imaging Case Study xiv Computed tomography xiv Picture archiving and communication system xv T1, T2, and FLAIR MRI xvi MR spectroscopy and a virtual biopsy xvii Functional MRI xviii Diffusion tensor MR imaging xviii MR guided biopsy xx Pathology xxi Positron emission tomography? xxi Treatment and follow-up xxii 1 Sketches of the Standard Imaging Modalities: Different Ways of Creating Visible Contrast Among Tissues 1 "Roentgen has surely gone crazy!" 2 Different imaging probes interact with different tissues in different ways and yield different kinds of medical information 4 Twentieth-century (analog) radiography and fluoroscopy: contrast from differential attenuation of X-rays by tissues 7 Twenty-first century (digital) images and digital planar imaging: computer-based images and solid-state image receptors 16 Computed tomography: three-dimensional mapping of X-ray attenuation by tissues 17 Nuclear medicine, including SPECT and PET: contrast from the differential uptake of a radiopharmaceutical by tissues 20 Diagnostic ultrasound: contrast from differences in tissue elasticity or density 26 Magnetic resonance imaging: mapping the spatial distribution of spin-relaxation times of hydrogen nuclei in tissue water and lipids 28 Appendix: selection of imaging modalities to assist in medical diagnosis 30 References 36 2 Image Quality and Dose: What Constitutes a "Good" Medical Image? 37 A brief history of magnetism 37 About those probes and their interactions with matter . . . 39 The image quality quartet: contrast, resolution, stochastic (random) noise, artifacts - and always dose 47 Quality assurance 57 Known medical benefits versus potential radiation risks 61 3 Creating Subject Contrast in the Primary X-ray Image:
Projection Maps of the Body from Differential Attenuation of X-rays by Tissues 67 Creating a (nearly) uniform beam of penetrating X-rays 69 Interaction of X-ray and gamma-ray photons with tissues or an image receptor 75 What a body does to the beam: subject contrast in the pattern of X-rays emerging from the patient 83 What the beam does to a body: dose and risk 87 4 Twentieth-century (Analog) Radiography and Fluoroscopy: Capturing the X-ray Shadow with a Film Cassette or an Image Intensifier Tube plus Electronic Optical Camera Combination 91 Recording the X-ray pattern emerging from the patient with a screen-film image receptor 92 Prime determinants/measures of image quality: contrast, resolution, random noise, artifacts, . . . and, always, patient dose 98 Special requirements for mammography 114 Image intensifier-tube fluoroscopy: viewing in real time 122 Conclusion: bringing radiography and fluoroscopy into the twenty-first century with solid-state digital X-ray image receptors 125 Reference 126 5 Radiation Dose and Radiogenic Risk: Ionization-Induced Damage to DNA can cause Stochastic, Deterministic, and Teratogenic Health Effects - And How To Protect Against Them 127 Our exposure to ionizing radiation has doubled over the past few decades 127 Radiation health effects are caused by damage to DNA 129 Stochastic health effects: cancer may arise from mutations in a single cell 132 Deterministic health effects at high doses: radiation killing of a large number of tissue cells 139 The Four Quartets of radiation safety 146 References 151 6 Twenty-first Century (Digital) Imaging: Computer-Based Representation, Acquisition, Processing, Storage, Transmission, and Analysis of Images 152 Digital computers 153 Digital acquisition and representation of an image 157 Digital image processing: enhancing tissue
contrast, SNR, edge sharpness, etc. 166 Computer networks: PACS, RIS, and the Internet 168 Image analysis and interpretation: computer-assisted detection 170 Computer and computer-network security 172 Liquid crystal displays and other digital displays 173 The joy of digital 174 7 Digital Planar Imaging: Replacing Film and Image Intensifiers with Solid State, Electronic Image Receptors 176 Digital planar imaging modalities 176 Indirect detection with a fluorescent screen and a CCD 178 Computed radiography 178 Digital radiography with an active matrix flat panel imager 179 Digital mammography 184 Digital fluoroscopy and digital subtraction angiography 186 Digital tomosynthesis: planar imaging in three dimensions 189 References 190 8 Computed Tomography: Superior Contrast in Three-Dimensional X-Ray Attenuation Maps 191 Computed tomography maps out X-ray attenuation in two and three dimensions 192 Image reconstruction 198 Seven generations of CT scanners 204 Technology and image quality 208 Patient- and machine-caused artifacts 219 Dose and QA 221 Appendix: mathematical basis of filtered back-projection 229 References 233 9 Nuclear Medicine: Contrast from Differential Uptake of a Radiopharmaceutical by Tissues 234 Unstable atomic nuclei: radioactivity 235 Radiopharmaceuticals: gamma- or positron-emitting radionuclei attached to organ-specific agents 245 Imaging radiopharmaceutical concentration with a gamma camera 248 Static and dynamic studies 254 Tomographic nuclear imaging: SPECT and PET 260 Quality assurance and radiation safety 270 References 273 10 Diagnostic Ultrasound: Contrast from Differences in Tissue Elasticity or Density Across Boundaries 274 Medical ultrasound 274 The US beam: MHz compressional waves in tissues 277 Production of an ultrasound beam and detection of
echoes with a transducer 280 Piezoelectric transducer elements 281 Transmission and attenuation of the beam within a homogeneous material 285 Reflection of the beam at an interface between materials with different acoustic impedances 288 Imaging in 1 and 1 × 1 dimensions: A- and M-modes 291 Imaging in two, three, and four dimensions: B-mode 294 Doppler imaging of blood flow 300 Elastography 302 Safety and QA 303 11 MRI in One Dimension and with No Relaxation: A Gentle Introduction to a Challenging Subject 307 Prologue to MRI 308 "Quantum" approach to proton nuclear magnetic resonance 310 Magnetic resonance imaging in one dimension 316 "Classical" approach to NMR 321 Free induction decay imaging (but without the decay) 331 Spin-echo imaging (still without T1 or T2 relaxation) 338 MRI instrumentation 343 Reference 351 12 Mapping T1 and T2 Relaxation in Three Dimensions 352 Longitudinal spin relaxation and T1 353 Transverse spin relaxation and T2-w images 364 T2∗ and the gradient-echo (G-E) pulse sequence 372 Into two and three dimensions 374 MR imaging of fluid movement/motion 382 13 Evolving and Experimental Modalities 387 Optical and near-infrared imaging 388 Molecular imaging and nanotechnology 390 Thermography 392 Terahertz (T-ray) imaging of epithelial tissues 393 Microwave and electron spin resonance imaging 393 Electroencephalography, magnetocardiography, and impedance imaging 394 Photo-acoustic imaging 396 Computer technology: the constant revolution 397 Imaging with a crystal ball 399 References 399 Suggested Further Reading 400 Index 403.
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Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, 2017. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries.
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