Cone Beam Computed Tomography E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 567

Veröffentlichungsjahr: 2013

Beschreibung

Written for the clinician, Cone Beam Computed Tomography helps the reader understand how CBCT machines operate, perform advanced diagnosis using CT data, have a working knowledge of CBCT-related treatment planning for specific clinical tasks, and integrate these new technologies in daily practice. This comprehensive text lays the foundation of CBCT technologies, explains how to interpret the data, recognize main pathologies, and utilize CBCT for diagnosis, treatment planning, and execution. Dr. Sarment first addresses technology and principles, radiobiologic risks, and CBCT for head and neck anatomy. The bulk of the text discusses diagnosis of pathologies and uses of CBCT technology in maxillofacial surgical planning, orthodontic and orthognathic planning, implant surgical site preparation, CAD/CAM surgical guidance, surgical navigation, endodontics airway measurements, and periodontal disease.

Leseprobe

Contents

Contributors

Preface

Acknowledgments

Oral and Maxillofacial Diagnosis and Applications

1 Technology and Principles of Cone Beam Computed Tomography

Section 1: Overview of compact cone beam CT systems

Section 2: Imaging basics for compact cone beam CT systems

Imaging performance

References

2 The Nature of Ionizing Radiation and the Risks from Maxillofacial Cone Beam Computed Tomography

Configuration of matter

Nature of ionizing radiation

Production of X-rays

X-ray production

Interaction of X-rays with matter

Biological effects of ionizing radiation

Risk from CBCT examinations

Methods to minimize radiation dose from CBCT exams

Units of radiation

References

3 Diagnosis of Jaw Pathologies Using Cone Beam Computed Tomography

Protocol for reviewing the CBCT volume

Evaluating pathologic lesions

Pathologic lesions of the jaws

Radiopaque lesions

Radiolucent lesions

Slow-growing radiolucent lesions

Rapidly growing lesions

The dentist’s role

Additional reading

4 Diagnosis of Sinus Pathologies Using Cone Beam Computed Tomography

Paranasal sinuses

Temporal bone

External auditory canal

Skull base

References

5 Orthodontic and Orthognathic Planning Using Cone Beam Computed Tomography

Introduction

Applications of 3D CBCT imaging for diagnosis and treatment planning

Longitudinal assessments using CBCT

References

6 Three-Dimensional Planning in Maxillofacial Reconstruction of Large Defects Using Cone Beam Computed Tomography

Introduction

CBCT-based virtual planning of resection and reconstruction

Discussion

References

7 Implant Planning Using Cone Beam Computed Tomography

Introduction

Image quality and implant planning

Anatomic evaluation

Diagnosis

Immediate implantation

Small implant restorations

Evaluation of the edentulous arch

Scanning update

Conclusion

References

8 CAD/CAM Surgical Guidance Using Cone Beam Computed Tomography

Introduction

Rapid prototyping and medical modeling

Scanning appliances

CBCT imaging protocols

Collaborative accountability

CAD/CAM surgical guides

Specialized guide design options

Discussion

Conclusions

References

9 Assessment of the Airway and Supporting Structures Using Cone Beam Computed Tomography

Background

Airway dimensional relationships to airway resistance

Purpose

Imaging

Facial growth and airway

Arthrides

Condylysis

Idiopathic juvenile arthritis

Summary

References

10 Endodontics Using Cone Beam Computed Tomography

Introduction

Endodontic disease

Advantages of limited field of view CBCT in endodontics

Limitations of 2D imaging in endodontics

Limitations of limited field of view CBCT in endodontics

Endodontic applications of CBCT

1. Evaluation of anatomy and complex morphology

2. Differential diagnosis

3. Intra- or postoperative assessment of complications

4. Dentoalveolar trauma

5. Resorption

6. Presurgical case planning

7. Dental implant case planning

8. Assessment of endodontic treatment outcomes

Acknowledgment

References

11 Periodontal Disease Diagnosis Using Cone Beam Computed Tomography

Periodontal diseases

Advanced imaging for periodontal applications

Cone beam computed tomography

Conclusion

References

Index

This edition first published 2014 © 2014 by John Wiley & Sons, Inc

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Library of Congress Cataloging-in-Publication Data

Cone beam computed tomography : oral and maxillofacial diagnosis and applications / [edited by] David Sarment.          p.; cm.     Includes bibliographical references and index.

   ISBN 978-0-470-96140-7 (pbk. : alk. paper) – ISBN 978-1-118-76902-7 – ISBN 978-1-118-76906-5 (epub) – ISBN 978-1-118-76908-9 (mobi) – ISBN 978-1-118-76916-4 (ePdf)I. Sarment, David P., editor of compilation. [DNLM: 1. Stomatognathic Diseases–radiography. 2. Cone-Beam Computed Tomography–methods. WU 140]     RK309     617.5′22075722–dc23

2013026841

A catalogue record for this book is available from the British Library.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.

Cover design by Jen Miller Designs

To my wife SylvieTo my children Lea, Myriam, and Nathanyel

Contributors

Sharon L. Brooks, DDS, MSProfessor Emerita, Department of Periodontics and Oral MedicineUniversity of Michigan School of DentistryAnn Arbor, Michigan, USA

Lucia H. S. Cevidanes, DDS, MS, PhDAssistant Professor, Department of OrthodonticsUniversity of Michigan School of DentistryAnn Arbor, Michigan, USA

João Roberto Gonçalves, DDS, PhDAssistant Professor, Department of Pediatric DentistryFaculdade de OdontologiaUniversidade Estadual Paulista, Araraquara, Brazil

Christian Güldner, MDSpecialist in ENT, Department of ENT, Head and Neck SurgeryUniversity of MarburgGermany

David C. Hatcher, DDS, MSc, MRCD(c)Adjunct Professor, Department of OrthodonticsUniversity of the Pacific School of DentistrySan Francisco, California, USAClinical Professor, Orofacial SciencesUniversity of California–San Francisco School of DentistrySan Francisco, California, USAClinical ProfessorRoseman University College of Dental MedicineHenderson, Nevada, USAPrivate practiceDiagnostic Digital ImagingSacramento, California, USA

Matthew W. Jacobson, MSc, PhDSenior Research ScientistXoran Technologies, Inc.Ann Arbor, Michigan, USA

Lars U. Lahoda, MD, PhDPlastic surgeon, Department of Plastic SurgeryUniversity of Groningen and University Medical Center GroningenGroningen, the Netherlands

Martin D. Levin, DMDDiplomate, American Board of EndodonticsChair, Dean’s Council and Adjunct Associate Professor of EndodonticsUniversity of Pennsylvania, School of Dental MedicinePhiladelphia, Pennsylvania, USAPrivate practiceChevy Chase, Maryland, USA

Sanjay M. Mallya, BDS, MDS, PhDAssistant Professor and Postgraduate Program DirectorOral and Maxillofacial RadiologyUniversity of California–Los Angeles School of DentistryLos Angeles, California, USA

George A. Mandelaris, DDS, MSDiplomate, American Board of PeriodontologyPrivate practicePeriodontics and Dental Implant SurgeryPark Ridge and Oakbrook Terrace, Illinois, USAClinical Assistant Professor, Department of Oral and Maxillofacial SurgeryLouisiana State University School of DentistryNew Orleans, Louisiana, USA

Aaron Miracle, MDResident physician, Department of Radiology and Biomedical ImagingUniversity of California–San FranciscoSan Francisco, California, USA

Beatriz Paniagua, PhDAssistant ProfessorDepartment of PsychiatryDepartment of Computer ScienceUniversity of North CarolinaChapel Hill, North Carolina, USA

Gerry M. Raghoebar, DDS, MD, PhDProfessor, Oral and maxillofacial surgeonUniversity of Groningen and University Medical Center GroningenGroningen, the Netherlands

Harry Reintsema, DDSMaxillofacial Prosthodontist, Department of Oral and Maxillofacial SurgeryUniversity of Groningen and University Medical Center GroningenGroningen, the Netherlands

Alan L. Rosenfeld, DDS, FACDDiplomate, American Board of PeriodontologyPrivate practicePeriodontics and Dental Implant SurgeryPark Ridge and Oakbrook Terrace, Illinois, USAClinical Professor, Department of PeriodontologyUniversity of Illinois College of DentistryChicago, Illinois, USAClinical Assistant Professor, Department of Oral and Maxillofacial SurgeryLouisiana State University School of DentistryNew Orleans, Louisiana, USA

David Sarment, DDS, MSDiplomate, American Board of PeriodontologyPrivate practiceImplantology and PeriodonticsAlexandria, Virginia, USA

Rutger Schepers, DDS, MDMaxillofacial Surgeon, Department of Oral and Maxillofacial SurgeryUniversity of Groningen and University Medical Center GroningenGroningen, the Netherlands

Martin Styner, PhDAssociate ProfessorDepartment of Computer ScienceUniversity of North CarolinaChapel Hill, North Carolina, USA

Bart Vandenberghe, DDS, MSc, PhDAdvimago, Center for Advanced Oral ImagingBrussels, BelgiumProsthetics Section, Department of Oral Health SciencesKU Leuven, Belgium

Arjan Vissink, DDS, MD, PhDProfessor, Oral and maxillofacial surgeonUniversity of Groningen and University Medical Center GroningenGroningen, the Netherlands

Stuart C. White, DDS, PhDProfessor Emeritus, Oral and Maxillofacial RadiologyUniversity of California–Los Angeles School of DentistryLos Angeles, California, USA

Max J. Witjes, DDS, MD, PhDAssistant Professor, Department of Oral and Maxillofacial SurgeryUniversity of Groningen and University Medical Center GroningenGroningen, the Netherlands

Preface

Technology surrounds our private and professional lives, improving at ever-accelerating speeds. In turn, medical imaging benefits from general enhancements in computers, offering faster and more refined views of our patients’ anatomy and disease states. Although this Moore’s law progression appears to be exponential, it has actually been almost a century since mathematician Johann Radon first laid the groundwork for reconstruction of a three-dimensional object using a great number of two-dimensional projections. The first computed tomography (CT) scanner was invented by Sir Godfrey Hounsfield, after he led a team to build the first commercial computer at Electric and Musical Industries. The theoretical groundwork had been published a few years earlier by a particle physicist, Dr. Allan Cormack. In 1971, the first human computed tomography of a brain tumor was obtained. In 1979, the year Cormack and Hounsfield received the Nobel Prize for their contribution to medicine, more than a thousand hospitals had adopted the new technology. Several generations of computed tomography scanners were later developed, using more refined detectors, faster rotations, and more complex movement around the body. In parallel, starting in the mid-1960s, cone beam computed tomography (CBCT) prototypes were developed, initially for radiotherapy and angiography. The first CBCT was built in 1982 at the Mayo clinic. Yet, computers and detectors were not powerful enough to bring CBCT to practical use. It is only within the last fifteen years that CBCT machines could be built at affordable costs and reasonable sizes. Head and neck applications were an obvious choice.

Although the technology allows for outstanding image quality and ease of use, we should not confuse information with education, data with knowledge. Doctors treat disease with the ultimate purpose to provide a good quality of life to patients. To do so, an in-depth knowledge of diagnosis and treatment methods is necessary. This textbook aims at providing detailed understanding of CBCT technology and its impact on oral and maxillofacial medicine. To achieve the goal of presenting a comprehensive text, world renowned engineers and clinicians from industry, academic, and private practice backgrounds came together to offer the reader a broad spectrum of information.

The clinician will want to jump in and utilize images for diagnostic and treatment purposes. However, a basic understanding of CBCT properties is essential to better interpret the outcome. Trying to comprehend electronics and formulas is daunting to most of us, but Dr. Jacobson manages, in the firstchapter, to present the anatomy of the machine in an attractive and elegant way. Dr. Jacobson is themagician behind the scene who has been concerned for many years with image quality, radiation, and speed. In his chapter, he opens the hood and makes us marvel at the ingeniousness and creativity necessary to build a small CBCT scanner.

The next three chapters are written by oral and maxillofacial radiologists, as well as head and neck radiologists. These two groups of specialists possess immense expertise in head and neck diseases and should be called upon whenever any pathology might be present. In the second chapter, Doctors Mallya and White address the majorissue of radiobiology risks. Their chapter allows us to make sound and confident judgment, so that X-ray emitting CBCT is only used when the clinical benefits largely outweigh the risk.Dr. Brooks, a pioneer and mentor to us all, reviews major relevant pathologies and reminds us that findings can often be incidental. Drs. Miracle and Christian’s unique chapter is a first: it introduces the use of CBCT for pathologies usually studied on medical CTs.

The next chapters address clinical applications. Dr. Cevidanes and her team, who have pioneered the study of orthognathic surgeries’ long-term stability using three-dimensional imaging, review the state of scientific knowledge in orthodontics. Next, Dr. Shepers and his colleagues share with us the most advanced surgical techniques they have invented while taking advantage of imaging. We introduce the use of CBCT for everyday implantology to make way to Drs. Mandelaris and Rosenfeld, who present the most advanced use of CAD/CAM surgical guidance for implantology, a field they have led since its inception. Dr. Hatcher, an early adopter and leader in dental radiology, is the expert in three-dimensional airway measurement, which he shares for the first time in a comprehensive chapter. Dr. Levine was first to measure the impact of CBCT in endodontics, which he demonstrates in his unique chapter. Finally, Dr. Vandenberghe shows us the way to use CBCT in periodontics, a new field with promising research he has in great part produced.

At the turn of the century, some of us were asked by a small start-up company to estimate the number of CBCT in dental offices in years to come. Our insight was critical to the business plan, and we anticipated the company could expect to sell about fifteen units per year in the United States. Looking back, it is difficult to comprehend how we could have been so wrong! Immersed in existing options, we were unable to imagine how our practices could be quickly transformed. We should also recall that, at the time, many other electronics now woven to our personal lives were to be invented. So today, we wonder what comes next. This book is a detailed testimony of our knowledge and a window to the near future. This time, we should attempt to use our imagination. We are clearly at the beginning of an era where technological advances assist patient care. The thought leaders who wrote this book are showing us the road to our future.

Acknowledgments

I would like to express my gratitude to the many people who have helped bring this book together, and to those who have developed the outstanding core technology around which it revolves. The topic of this text embodies interdisciplinary interaction at its best: clinical need, science, and engineering were intertwined for an outstanding outcome. Behind each of these disciplines are dedicated individuals and personal stories which I was blessed to often share. I hope to be forgiven by those who are not cited here.

I am thankful to the editors at Wiley Blackwell, who had the foresight many years ago to seek and support this project. In particular, Mr. Rick Blanchette envisioned this book and encouraged me to dive into its conception. To Melissa Wahl, Nancy Turner, and their team, I am grateful for their relentless “behind the scenes” editorial work.

I am forever indebted to the co-authors of the book. They are leaders of their respective fields, busy treating patients, discovering new solutions, or lecturing throughout the word. Yet, a short meeting, a phone call, or a letter was enough to have them on board with writing a chapter. They spent countless hours refining their text, sacrificing precious moments with their families in order to share their passion. As always, the work was much greater than initially anticipated, yet it was completed to the finest detail and greatest quality.

At the University of Michigan, I received the unconditional support of several experienced colleagues. In particular, Professors WilliamGiannobile, Laurie McCauley, and Russel Taichman were immensely generous of their time, expertise, and friendship while I struggled as a young faculty member.

Many engineers spend nights and weekends building, programming, and refining cone beam machines. To them all, we must be thankful. I am particularly grateful to my friend Pedja Sukovic, former CEO at Xoran Technologies in Ann Arbor, Michigan. We first met when he was a PhD student and I was a young faculty. He came to the dental school as a patient, and casually asked if a three- dimensional radiograph of the head would be of interest to us. At the time, his mentor Neal Clinthorne and he had built a bench prototype in a basement laboratory. It was only a matter of time before it became one of the most sought-after machines in the world.

This work would simply have been unimaginable without the support of my family. I owe my grandmother Tosca Yulzari my graduate studies. She saw the beginning of this book but will not see its completion. My father, long gone, taught me the meaning of being a doctor. My best mentor and friend is my wife Sylvie, who has supported me unconditionally during almost two decades. Finally, I thank my children Lea, Myriam, and little Nathanyel, for giving me such joy and purpose.

David Sarment, DDS, MS

Cone Beam Computed Tomography

Oral and Maxillofacial Diagnosis and Applications

1

Technology and Principles of Cone Beam Computed Tomography

Matthew W.Jacobson

This chapter aims to convey a basic technical familiarity with compact Cone Beam Computedtomography (CBCT) systems, which have become prevalent since the late 1990s as enablers of in-officeCT imaging of the head and neck. The technical level of the chapter is designed to be accessible to current or candidate end users of this technology and is organized as follows. In Section 1, a high-level overview of these systems is given, with a discussion of their basic hardware components and their emergence as an alternative to conventional, hospital CT. Section 2 gives a treatment of imaging basics, including various aspects of how a CT image is derived, manipulated, and evaluated for quality.

Section 1: Overview of compact cone beam CT systems

Computed tomography (CT) is an imaging technique in which the internal structure of a subject is deduced from the way X-rays penetrate the subject from different source positions. In the most general terms, a CT system consists of a gantry which moves an X-ray source to different positions around the subject and fires an X-ray beam of some shape through the subject, toward an array of detector cells. The detector cells measure the amount of X-ray radiation penetrating the subject along different lines of response emanating from the source. This process is called the acquisition of the X-ray measurements. Once the X-ray measurements are acquired, they are transferred to a computer where they are processed to obtain a CT image volume. This process is called image reconstruction. Once image reconstruction has been performed, the computer components of the system make the CT image volume available for display in some sort of image viewing software. The topics of image reconstruction and display will be discussed at greater length in Section 2.

Cone beam computed tomography refers to CT systems in which the beam projected by the X-ray source is in the shape of the cone wide enough to radiate either all or a significant part of the volume of interest. The shape of the beam is controlled by the use of collimators, which block X-rays from being emitted into undesired regions of the scanner field of view. Figure 1.1 depicts a CBCT system of a compact variety suitable for use in small clinics. In the particular system shown in the figure, the gantry rotates in a circular path about the subject firing a beam of X-rays that illuminates the entire desired field of view. This results in a series of two-dimensional (2D) images of the X-ray shadow of the object that is recorded by a 2D array of detector cells. Cone beam CT systems with this particular scan geometry will be the focus of this book, but it is important to realize that in the broader medical imaging industry, CT devices can vary considerably both in the shape of the X-ray beam and the trajectory of the source.

Figure 1.1 The proposed design of DentoCAT. The patient is seated comfortably in chair (the chin-rest is not shown). DentoCAT features cone beam geometry, aSi:H detector array, PWLS and DE PWLS reconstruction methods.

Prior to the introduction of CBCT, it was common for CT systems to use so-called fan beam scan geometries in which collimators are used to focus the X-ray beam into a flat fan shape. In a fan beam geometry, the source must travel not only circularly around the subject but also axially along the subject’s length in order to cover the entire volume of interest. A helical (spiral) source trajectory is the most traditional method used to accomplish this and is common to most hospital CT scanners. The idea of fan beam geometries is that, as the source moves along the length of the subject, the X-ray fan beam is used to scan one cross-sectional slice of the subject at a time, each of which can be reconstructed individually. There are several advantages to fan beam geometries over cone beam geometries. First, since only one cross-section is being acquired at a time, only a 1-dimensional detector array is required, which lowers the size and cost of the detector. Second, because a fan beam only irradiates a small region of the object at a given time, the occurrence of scattered X-rays is reduced. In cone beam systems, conversely, there is a much larger component of scattered radiation, which has a corrupting effect on the scan (see “Common Image Artifacts” section). Finally, in a fan beam geometry, patient movement occurring during the scan will only degrade image quality in the small region of the subject being scanned when motion occurs. Conversely, in cone beam systems, where larger regions of anatomy are irradiated at a given time, patient movement can have a much more pervasive effect on image quality.