Table Of Content

Contributors † : deceased Andy AdamMBBS (Hons), FRCP, FRCS, Clive I. BartramFRCS, FRCP, FRCR Gisele Brasil Caseiras PhD FRCR, FFRRCSI (Hon) Emeritus Consultant, St Mark’s Hospital Research Fellow Professor of Interventional Radiology and Honorary Professor of Insitute of Neurology Department of Radiology Gastrointestinal Radiology University College London St Thomas’ Hospital Faculty of Medicine London, UK King’s College London Imperial College London, UK London, UK Jackie E. Brown BDS, MSc, FDSRCP, DDRRCR Consultant Oral and Maxillofacial E. Jane Adam MBBS, MRCP, FRCR Philip P. W. BearcroftFRCP, FRCR Radiologist Consultant Radiologist Consultant Radiologist Kings College London Dental Institute Department of Radiology Department of Radiology Guy’s Dental Hospital St George’s Hospital Cambridge University Hospitals NHS London, UK London, UK Foundation Trust Addenbrooke’s Hospital Dina F. CarolineMD, PhD Judith E. Adams MBBS, FRCR, FRCP Cambridge, UK Professor Emerita Chair, Diagnostic Radiology Department of Radiology Imaging Science and Biomedical Anna-Maria BelliDMRD, FRCR Temple University Hospital Engineering Consultant Vascular Radiologist and Philadelphia University of Manchester Reader in Radiology Pennsylvania, USA Honorary Consultant Radiologist Department of Radiology Royal Infirmary St George’s Hospital Silvia D. ChangMD, FRCP(C) Manchester, UK London, UK Assistant Professor University of British Columbia David J. Allison BSc, MD, MRCS, LRCP, MBBS, Anthony R. BerendtBM, BCh, FRCP Department of Radiology DMRD, FRCR, FRCP Consultant Physician-in-Charge Vancouver General Hospital Emeritus Professor of Imaging Bone Infection Unit Vancouver, Canada Imperial College Nuffield Orthopaedic Centre London, UK Oxford, UK W. K. ‘Kling’ ChongBMedSci, MD, MRCP, FRCR Consultant Neuroradiologist Sandra Allison MD Lol BermanFRCP, FRCR Department of Radiology Assistant Professor of Radiology University Department of Radiology Great Ormond Street Hospital for Director, Radiology Residency Program Addenbrooke’s Hospital Children NHS Trust Director, Ultrasound Cambridge, UK London, UK Georgetown University Hospital Washington DC, USA Martin J. K. Blomley† Bairbre ConnollyMBBCh, BAO, FRCSI, MCH, FFRRCSI, FRCP(C) Philip AnslowFRCR Carol A. BolesMD Medical Director and Division Head of Consultant Neuroradiologist Associate Professor of Radiology Image Guided Therapy Department of Radiology Associate, Surgical Sciences Pediatric Interventional Radiologist Radcliffe Infirmary Orthopedic Surgery Assistant Professor, University of Toronto Oxford, UK Wake Forest University Department of Diagnostic Imaging North Carolina, USA The Hospital for Sick Children Susan M. AscherMD Toronto, Canada Georgetown University Medical Center Jamshed B. BomanjiMBBS, MSc, PhD Washington DC, USA Consultant in Nuclear Medicine Susan J. CopleyMBBS, MD, MRCP, FRCR UCLH Trust Consultant Radiologist and Honorary Zelena A. AzizMD, MRCP, FRCR Middlesex Hospital Senior Lecturer Consultant Radiologist London, UK Radiology Department Department of Radiology Hammersmith Hospital London Chest Hospital London, UK London, UK FFMM--FF00116633--vv II..iinndddd iixx 66//2299//0077 99::0022::0055 PPMM x CONTRIBUTORS David O. CosgroveMA, MSc, FRCP, FRCR Robert J. EckersleyPhD Philip C. GoodmanMD Emeritus Professor Research Associate Professor of Radiology Imaging Sciences Department Imaging Sciences Department Chief, Thoracic Imaging Division Faculty of Medicine Faculty of Medicine Department of Radiology Imperial College Imperial College Duke University Medical Center Hammersmith Hospital Hammersmith Hospital Durham London, UK London, UK North Carolina, USA Nigel CowanPGDipLATHE, FRCP Andrew J. EvansMRCP, FRCR Isky GordonFRCR, FRCP Oxford, UK Consultant Radiologist Professor of Paediatric Imaging Nottingham Breast Institute Institute of Child Health Justin J. CrossMRCP, FRCR Nottingham City Hospital London, UK Consultant Neuroradiologist Nottingham, UK Department of Radiology Nicholas GourtsoyiannisFRCR (Hon) Addenbrooke’s Hospital Jane EvansonBSc, MBBS, MRCP, FRCR Professor of Radiology Cambridge, UK Consultant Neuroradiologist, Barts & The University of Crete London Hospital NHS Trust Faculty of Medicine Paras DalalBSc, MRCP, FRCR The Royal London Hospital Heraklion, Crete Research Fellow in Thoracic Imaging London, UK Greece Department of Radiology Royal Brompton Hospital Laura FenderBMedSci, BMBS, MRCP, FRCR Andrew J. GraingerBM, BS, MRCP, FRCR London, UK Consultant Radiologist Consultant Radiologist Nottingham University Hospital Chapel Allerton Orthopaedic Centre Maria DaskalogiannakiMD Nottingham, UK Leeds Teaching Hospitals Registrar in Radiology Leeds, UK Department of Radiology Alan H. FreemanMBBS, FRCR University Hospital of Heraklion Consultant Radiologist Ronald G. GraingerMB ChB(Hons), MD, FRCP, Crete, Greece Department of Radiology DMRD, FRCR, FACR(Hon), FRACR(Hon) Addenbrooke’s Hospital Professor of Diagnostic Radiology A. Mark DaviesFRCR Cambridge, UK (Emeritus) Consultant Radiologist University of Sheffield Royal Orthopaedic Hospital Julia GatesMD Honorary Consultant Radiologist Birmingham, UK Assistant Professor of Radiology Royal Hallamshire Hospital and Northern Department of Radiology General Hospital Adrian K. DixonMD, FRCR, FRCP, FRCS, Tufts University School of Medicine Sheffield, UK FMedSci, FFRRCSI (Hon), FRANZCR (Hon) Springfield Professor of Radiology Massachusetts, USA Philippe GrenierFRCR (Hon) Department of Radiology Professor of Radiology Addenbrooke’s Hospital Robert N. GibsonMBBS, MD, FRANZCR, DDU Service de Radiologie Polyvalente University of Cambridge Professor of Radiology Diagnostique et Interventionnelle Cambridge, UK Department of Radiology Hôpital Pitié-Salpêtrière University of Melbourne Paris, France Rose de BruynDMRD, FRCR Royal Melbourne Hospital Consultant Radiologist Victoria, Australia Roxana S. GunnyBS, BSc, MRCP, FRCR Department of Radiology Consulant Neuroradiologist Great Ormond Street Hospital for Sick Raymond J. GodwinMA, MB, Bchir, FRCP, FRCR Department of Radiology Children NHS Trust Consultant Radiologist Great Ormond Street Hospital for London, UK Department of Radiology Children NHS Trust West Suffolk Hospital London, UK Claudio DefilippiMD Suffolk, UK Consultant Radiologist Christine M. HallMBBS, DMRD, FRCR MD Department of Radiology Karen GoldstoneBSc, MSc, Csci, FIPEM Professor of Paediatric Radiology OIRM - S. Anna Hospital Radiation Protection Advisor Great Ormond Street Hospital for Turin, Italy Acting Head of Department of Medical Children NHS Trust Physics and Clinical Engineering London, UK Sujal R. Desai MD, MRCP, FRCR East Anglian Regional Radiation Consultant Radiologist Protection Service (EARRPS) David M. HansellMD, FRCP, FRCR, LRSM Department of Radiology Addenbrooke’s Hospital Professor of Thoracic Imaging King’s College Hospital Cambridge, UK Department of Radiology London, UK Royal Brompton Hospital London, UK FFMM--FF00116633--vv II..iinndddd xx 66//2299//0077 99::0022::0055 PPMM CONTRIBUTORS xi George G. Hartnell FRCR, FRCP Adrian K. P. LimMD, FRCR Stuart E. Mirvis MD, FACR Director of Cardiovascular and Interven- Consultant Radiologist and Professor of Radiology tional Radiology Senior Lecturer Department of Radiology Department of Radiology Imaging Sciences Department University of Baystate Medical Center Faculty of Medicine Imperial College Maryland School of Medicine Springfield Hammersmith Hospital Baltimore Professor of Radiology London, UK Maryland, USA Tufts University Medical School Boston David J. LomasMA, MB, BChir, FRCR, FRCP Sameh K. Morcos FRCS, FFRRCSI, FRCR Massachusetts, USA Professor of Clinical Magnetic Resonance Professor of Diagnostic Imaging Imaging University of Sheffield Hedvig Hricak MD, Dr. Med, SC, Dr. h.c, FRCR (Hon) Department of Radiology Consultant Radiologist Chairman, Department of Radiology Addenbrooke’s Hospital Department of Diagnostic Imaging Carroll and Milton Petrie Chair Cambridge, UK Northern General Hospital Professor of Radiology, Weill Medical Sheffield, UK College of Cornell University Sharyn L. S. MacDonaldMBChB, FRANZCR Memorial Sloan-Kettering Cancer Center Consultant Radiologist Robert A. MorganMBChB, MRCP, FRCR New York, USA Department of Radiology Consultant Radiologist Christchurch Hospital Department of Radiology James E. JacksonMRCP, FRCR Christchurch, New Zealand St George’s Hospital Consultant Radiologist London, UK Department of Imaging David MacVicarMA, MRCP, FRCP, FRCR Hammersmith Hospital Consultant Radiologist Iain MorrisonMBBS, MRCP, FRCR London, UK Department of Diagnostic Radiology Consultant Radiologist Royal Marsden Hospital Radiology Department H. Rolf JägerFRCR, MD Sutton, UK Kent and Canterbury Hospital Reader in Neuroradiology Canterbury, UK Institute of Neurology Adrian ManhireBSc, MBBS, FRCP, FRCR University College London Consultant Radiologist Nestor L. MüllerMD, PhD, FRCPC Honorary Consultant Neuroradiologist Nottingham City Hospital Professor and Chairman The National Hospital for Neurology Nottingham, UK Department of Radiology and Neurosurgery and University College University of British Columbia Hospital Tarik F. MassoudMA, MD, PhD, FRCR Head and Medical Director London, UK University Lecturer and Honorary Department of Radiology Consultant in Neuroradiology Vancouver General Hospital Jonathan J. JamesBMBS, FRCR University Department of Radiology Vancouver, Canada University of Cambridge School of Consultant Radiologist Clinical Medicine Graham MunnekeMRCP, FRCR Nottingham Breast Institute Nottingham City Hospital Addenbrooke’s Hospital Consultant in Interventional Radiology Nottingham, UK Cambridge, UK Department of Radiology St. George’s Hospital Renee M. KendzierskiDO Kieran McHughFRCPI, DCH, FRCR London, UK Assistant Professor of Radiology Department of Radiology Department of Radiology Great Ormond Street Hospital for Sick Alison D. MurrayMB ChB (Hons), FRCR, FRCP Temple University Hospital Children NHS Trust Senior Lecturer in Radiology Philadelphia London, UK Department of Radiology Pennsylvania, USA University of Aberdeen James MeaneyFRCR, FFRRCSI Aberdeen, UK Dow-Mu KohMRCP, FRCP Director of MRI St James’s Hospital Richard A. NakielnyFRCR Senior Lecturer and Honorary Consultant Department of Radiology Dublin, Ireland Honorary Clinical Lecturer Royal Marsden Hospital Directorate of Medical Imaging & Sutton, UK Hylton B. MeireFRCR, DRCOG, DMRD Medical Physics Consultant Radiologist (Retired) Royal Hallamshire Hospital Isla LangMBChB, MRCP, FRCR King’s College Hospital Sheffield, UK London, UK Consultant Paediatric Radiologist Hrudaya NathMD Sheffield Children’s Hospital Sheffield, UK Kenneth A. Miles MD, FRCR, MSc, FRCP Professor of Radiology Clinical Imaging Sciences Centre Department of Radiology Brighton and Sussex Medical School University of Alabama Hospitals University of Sussex Birmingham Falmar, Brighton, UK Alabama, USA FFMM--FF00116633--vv II..iinndddd xxii 66//2299//0077 99::0022::0066 PPMM xii CONTRIBUTORS Tony NicholsonMSc, FRCR Sheila RankinFRCR John RoutBDS, FDSRCS, MDentSc, DDRRCR, FRCR Consultant Vascular Radiologist Consultant Radiologist Consultant Oral and Maxillofacial Department of Clinical Radiology Department of Radiology Radiologist Leeds Teaching Hospitals Guy’s and St. Thomas’ Foundation Trust Birmingham Dental Hospital Leeds, UK London, UK Birmingham, UK Amaka C. OffiahBSc, MBBS, MRCP, FRCR, PhD Padma RaoMBBS, BSc, MRCP, FRCR, Michael B. RubensMB, DMRD, FRCR Consultant Radiologist (Academic) FRANZCR Consultant Radiologist Great Ormond Street Hospital for Consultant Paediatric Radiologist Department of Radiology Children NHS Trust Royal Children’s Hospital Royal Brompton Hospital London, UK Parkville London, UK Melbourne Simon PadleyBSc, MBBS, FRCP, FRCR Victoria, Australia Asif SaifuddinBSc (Hons), MBChB, MRCP, FRCR Consultant Radiologist Consultant Radiologist Department of Radiology Christine ReekBSc, FRCR Department of Radiology Chelsea and Westminster Hospital Consultant Radiologist Royal National Orthopaedic Hospital London, UK Department of Radiology NHS Trust Greenfield Hospital Stanmore, UK Martyn N. J. PaleyPhD, FInstP Leicester, UK Professor of MR Physics Evis Sala MD, PhD, FRCR Academic Radiology John H. ReynoldsDMRD, FRCR, MMedSci University Lecturer in Oncology Imaging University of Sheffield Consultant Radiologist University Department of Radiology Sheffield, UK Birmingham Heartlands Hospital Addenbrooke’s Hospital Birmingham, UK Cambridge, UK Nickolas PapanikolaouPhD Biomedical Engineer Rodney H. ReznekFRANZCR (Hon), FRCP, FRCR Caron Sandhu FRCR Department of Radiology Professor of Diagnostic Imaging Consultant Radiologist University Hospital of Heraklion The Centre for Cancer Imaging Department of Radiology Crete, Greece St Bartholomew’s Hospital and The Guy’s and St. Thomas’ Hospital London Queen Mary’s School of London, UK Jai PatelMBChB, MRCP, FRCR Medicine and Dentistry Consultant Vascular Radiologist London, UK Dawn SaundersMD, MRCP, FRCR Department of Clinical Radiology Consultant Neuroradiologist St James’s University Hospital Philip M. RichBSc, FRCS, FRCR Department of Radiology Leeds, UK Consultant Neuroradiologist Great Ormond Street Hospital for Department of Neuroradiology Children NHS Trust Anne PatersonMBBS, MRCP, FRCR, FFR RCSI Atkinson Morley Wing London, UK Consultant Paediatric Radiologist St George’s Hospital Radiology Department London, UK Daniel J. ScoffingsMRCP, FRCR Royal Belfast Hospital for Sick Children Specialist Registrar in Neuroradiology Belfast, UK Andrea Rockall MD, BS, BSc, MRCP, FRCP Addenbrooke’s Hospital Department of Radiology Cambridge, UK Praveen PedduMRCS, FRCR St Bartholomew’s Hospital Specialist Registrar in Radiology London, UK Djilda SegermanMA, MSc, MIPEM Department of Radiology Head of Nuclear Medicine Physics King’s College Hospital Giles Roditi FRCP, FRCR Department of Medical Physics London, UK Consultant Radiologist Brighton and Sussex University Hospitals Department of Radiology NHS Trust A. Michael PetersBSc, MD, MSc, MRCP, Glasgow Royal Infirmary Brighton, UK MRCPath, FRCR Glasgow, UK Professor of Nuclear Medicine Kathirkama ShanmuganathanMD Brighton and Sussex Medical School Lee F. RogersMD Associate Professor of Radiology University of Sussex Clinical Professor of Radiology Department of Radiology Brighton, UK Department of Radiology University of Maryland School of University of Arizona Health Services Medicine William H. Ramsden BM, FRCR Tucson Baltimore Consultant Paediatric Radiologist Arizona, USA Maryland, USA Department of Clinical Radiology St James’s University Hospital Giles Rottenberg FRCR Ashley S. ShawMRCP, FRCR Leeds, UK Consultant Radiologist Consultant Radiologist Department of Radiology Department of Radiology Guy’s and St. Thomas’ Foundation Trust Addenbrooke’s Hospital London, UK Cambridge, UK FFMM--FF00116633--vv II..iinndddd xxiiii 66//2299//0077 99::0022::0066 PPMM CONTRIBUTORS xiii Satinder P. SinghMD, FCCP Mihra S. TaljanovicMD, MA Sarah J. VinnicombeBSc, MRCP, FRCR Associate Professor of Radiology Associate Professor of Clinical Radiology Consultant Radiologist Director Cardiac CT and Clinical Orthopedic Surgery Department of Radiology Director, Combined Cardiopulmonary Head - Musculoskeletal Imaging Section St Bartholomew’s Hospital and Abdominal Fellowship Department of Radiology London, UK Chief of Cardiopulmonary Radiology Tucson Department of Radiology Arizona, USA Gustav K. von SchulthessMD, PhD University of Alabama Hospitals Professor and Director Birmingham Andrew M. TaylorBA (Hons), BM BCh, MRCP Department of Radiology Alabama, USA FRCR University Hospital Consultant Radiologist Zurich, Switzerland S. Aslam A. SohaibMRCP, FRCR Department of Clinical Radiology Radiology Department Great Ormond Street Hospital for Iain D. WilkinsonBSc, MSc, PhD, CSci, Royal Marsden Hospital Children NHS Trust ARCP, FIPEM London, UK London, UK Reader in Magnetic Resonance & Consultant Clinical Scientist Alan SpriggMBChB, DCH, DRCOG, DMRD, FRCR, Stuart TaylorBSc, MD, MRCP, FRCR Academic Radiology FRCPCH Consultant Radiologist University of Sheffield and Consultant Paediatric Radiologist Department of Intestinal Imaging Sheffield Teaching Hospitals Sheffield Children’s Hospital St Marks Hospital NHS Foundation Trust Sheffield, UK Northwick Park Sheffield, UK Harrow, UK John M. StevensMBBS, DRACR, FRCR A. Robin M. Wilson FRCR, FRCP(E) Lyshom Department of Neuroradiology Henrik S. ThomsenMD Consultant Radiologist Radiology Department Professor and Chairman King’s College Hospital and The National Hospital for Neurology and Department of Diagnostic Radiology Guy’s and St Thomas’ Foundation Trusts Neurosurgery Copenhagen University Hospital London, UK London, UK Herlev, Denmark David J. WilsonMBBS, BSc, FRCP, FRCR Dennis J. StokerMB, FRCP, FRCS, FRCR Paolo TomaMD Consultant Musculoskeletal Radiologist Emeritus Consultant Radiologist Radiologist-in-Chief Nuffield Orthopaedic Centre and Henley-on-Thames, UK Radiology Department University of Oxford G. Gaslini Institute Oxford, UK Nicola H. StricklandBM BCh, MA (Hons), Genoa, Italy (Oxon), FRCP, FRCR Stuart J. YatesMSci, MSc, CSci, MIPEM Consultant Radiologist Peter TwiningFRCR, BSc, BS MB Principal Physicist Imaging Department Consultant Radiologist Department of Medical Physics & Clinical Hammersmith Hospitals NHS Trust Nottingham University Hospital Engineering Honorary Senior Lecturer Nottingham, UK Cambridge University Hospitals NHS Imperial College Foundation Trust London, UK John A. VerschakelenMD, PhD Cambridge, UK Professor of Chest Radiology Louise E. SweeneyMBBCH, BAO, DCH, DMRD, Department of Radiology FRCR, FFR, RCSI University Hospitals Gasthuisberg Consultant Paediatric Radiologist Leuven, Belgium Radiology Department Royal Belfast Hospital for Sick Children Belfast, UK FFMM--FF00116633--vv II..iinndddd xxiiiiii 66//2299//0077 99::0022::0077 PPMM Preface We hope that this 5th edition of Diagnostic Radiology will year basic course followed by two years of training in selected continue to build on the original vision of Professors Grainger subspecialties, the factual examination in the UK has moved to and Allison who, back in the early 1980s, saw the need for an earlier stage in training with less emphasis on some of the a ‘bible’ for doctors studying for postgraduate examinations diagnostic rarities so beloved by examiners of old. The cur- in radiology, and to provide a bench book for reporting riculum is now somewhat less comprehensive and the reduc- and reference. The success of the first four editions, which tion in size of this 5th Edition reflects that – down from three were extremely well received by an increasingly interna- volumes to two. In this electronic age there are many data- tional readership, speaks for the realisation of their dream. bases of images available on the internet, with accompanying Few could have predicted at that stage the extraordinary text. Nevertheless, we believe that well structured textbooks growth of radiology, or its increasing importance within all remain an essential part of medical education and practice as aspects of modern medicine. The unprecedented expansion in they present information in a format that facilitates learning, the imaging repertoire, together with the trend for increasing guiding the reader through an unfamiliar field. We are con- subspecialisation, have led to changes in training and in the vinced that Diagnostic Radiology will remain a valuable resource methods used for teaching and learning. This book has had for many years to come. to evolve to reflect these changes, adapting to the perceived We are again extremely grateful to the distinguished inter- needs of those facing postgraduate examinations and also to national cast of authors who have all worked hard to deliver all radiologists who wish to have an up-to-date basic general fresh and up-to-date material. We are also most grateful to textbook for ready reference and illustration. Michael Houston, Gavin Smith and Nora Naughton for their An attempt to cover every subject in detail would have professional skills and publishing expertise and to Jeremy resulted in a huge book that would have been very difficult to Rabouhans for invaluable help with proof reading. We could use. We have chosen to concentrate on those subjects that most never have done it without them! radiologists need to know well, and to pay special attention to the needs of trainee radiologists preparing for examinations. Andy Adam Because training throughout Europe is moving towards a three Adrian Dixon FFMM--FF00116633--vv II..iinndddd xxvv 66//2299//0077 99::0022::0077 PPMM Acknowledgements This edition could not have occured without the large amount leagues remained remarkably cheerful throughout and kept of work done by all the contributing authors and their col- strong heads even when chapters were late, images missing, leagues. However, the vision and overall planning of Michael and all the other hiccups that can hinder progress in a project Houston at Elsevier have been fundamental in bringing the of this kind. At a local level, all the Editors would like to thank book to fruition. So, too, has the meticulous gathering and their various secretaries, technicians and colleagues who have editing of material by Gavin Smith. Finally, the skilful copy- helped proofread, collect material and made various other editing, and other tasks provided by Nora Naughton, and invaluable contributions. her remarkable team, must not be forgotten; without them the Editors simply could not have managed. All of these col- The Editors FFMM--FF00116633--vv II..iinndddd xxvviiii 66//2299//0077 99::0022::0077 PPMM 1 CHAPTER Picture Archiving and Communication Systems (PACS) and Digital Radiology Nicola H. Strickland T he role of PACS Compression Advantages and disadvantages of PACS • Lossless • Advantages of PACS • Lossy • Disadvantages of PACS • Need for compression Planning for PACS Digitization policy • The PACS project team Teleradiology • Tendering for a PACS • Review of images from home • The PACS contract • Teleradiology linkage between two or more hospitals for joint • Economic considerations MDTMs • Purchasing versus leasing a PACS • Outsourcing of imaging examinations for reporting • PRE-PACS workflow and preparation • Tele-education • Acronyms: DICOM, HL7 and IHE Security PACS project implementation • User-specific log-in and password • Implementation of digital image acquisition prior to PACS • Monitor screen savers • Integration of PACS • Workstation time-outs ‘Value-added’ PACS • Encryption Modern PACS architecture • Audit trails • PACS networks • Firewalls • Storage requirements and solutions for PACS • Teleradiology security PACS workstations PACS training • Monitor quality on PACS workstations Quality assurance Conference room design • Plain radiography Graphic user interface • PACS workstations • Soft-copy tools PACS housekeeping Software concepts • Storage commitment • Prefetching • Modality performed procedure step Current and future directions of PACS THE ROLE OF PACS A picture archiving and communication system (PACS) aims to conjunction with the clinical details of the patient and the replace conventional analogue film and paper clinical request associated radiological report displayed in electronic format. forms and reports with a completely computerized electronic Clearly PACS must replace the functions of traditional X-ray network whereby digital images are viewed on monitors in film; i.e. image acquisition, storage, transportation and display. CChh0011--FF00116633..iinndddd 33 66//2288//0077 11::1100::2211 AAMM 4 SECTION 1 • IMAGING TECHNIQUES AND GENERAL ISSUES Were these the only roles of a PACS, it would be an extremely ing upon a potential time scale in which the hospital-wide complex and expensive means of replacing traditional film. A PACS is to be achieved, and deciding upon a scaleable PACS PACS must improve upon a film-based system, preferably in architecture. Ideally the whole hospital infrastructure should a cost-neutral manner. The major added value of a PACS is be adapted at the outset so that a hospital-wide PACS can efficiency of data management. be accommodated at a later stage. This includes providing True efficiency benefits can only be realized once a PACS an uninterruptable power supply (UPS), allowing sufficient is at least hospital-wide, since any more limited installation cabling space in floors and ceilings, and adapting the air con- means running two systems in parallel, i.e. it entails continu- ditioning system for PACS. The hospital information tech- ing to produce conventional film and moving it around the nology (IT) network is likely to need upgrading to enable hospital, as well as the cost of installing and maintaining a large amounts of image data to be transported, and it is advis- PACS. Thus, even if funds are limited initially, it is advisable able to install multiple PACS ‘drops’ (workstation outlets) so at least to aim and plan for growing the PACS installation that more PACS workstations can easily be added at a later into a hospital-wide system ultimately. This means decid- date. ADVANTAGES AND DISADVANTAGES OF PACS Although the concept of PACS has now been in existence for imaging study, remain in their correct orientation, and are over 20 years, advances in computer hardware technology only automatically chronologically ordered. Database searches enabled it to become a realistic clinical entity in the 1990s. for a particular patient or study are rapidly effected. Com- PACS installations are now rising exponentially worldwide, puterized data can easily be duplicated, i.e. ‘backed up’ as a and although most institutions with PACS have achieved a precaution against loss, and cheaply stored in a distant loca- completely filmless working environment, few function in a tion if desired for disaster recovery purposes. paperless mode. PACS has proved itself over the last 10 years • Viewing of images on monitors allows numerous post- in the clinical environment, however, and it would now be processing soft-copy manipulations: a range of different unthinkable not to implement PACS when installing a new window width and level settings can be applied to CT imaging department, or a new hospital. images, for example, within a fraction of a second, whereas previously further sheets of film had to be printed with the ADVANTAGES OF PACS appropriate settings for soft tissue, lung or bone as desired3,4. • There are some direct cost savings due to PACS: there is no There are a number of powerful advantages accruing from a longer a film budget, film packet cost or chemical process- hospital-wide PACS: ing. (The ability to print film need not be retained pro- • Once correctly acquired onto the PACS, no image can ever vided a CD burner is linked to the PACS to burn imaging be lost or misfiled and is always available when needed. This studies for transfer of patients outside the institution, or in is a major benefit considering that in many hospitals up to the event of a PACS failure or planned downtime). Ancillary 20 per cent of conventional films are missing at the time staff – filing clerks and darkroom technicians – are no l onger they are clinically required. In addition to the convenience needed. of always having the appropriate image available when it • The most frequently cited benefit of PACS by nonradiolog- is wanted for viewing, no patient is re-irradiated simply ical clinicians is the very substantial time saving incurred by because a previous key study has been lost. their never having to search for or retrieve films. This time • PACS facilitates the easy comparison of a patient’s current saving represents a considerable indirect financial benefit of and historical examinations, and of examinations performed a hospital-wide PACS, and should certainly be costed when on the same body part using different imaging techniques, a business case for PACS is being made. which is desirable in the interests of optimum clinical • After a hospital-wide PACS has been installed, old films practice, and always possible since none of the relevant can progressively be removed from the film filing room comparative images is missing1. (film store) starting with the oldest first. The timing of this • All images remain accessible from the PACS archives day manoeuvre will depend upon local and national policy, and night, every day of the year. but it has been shown5 that most radiological compari- • Simultaneous multilocation viewing of the same image sons are made with studies obtained during the preced- is possible on any workstation connected to the PACS ing 6 months, although this may be longer in institutions network, whereas hard-copy film can manifestly only be in with a large oncological or paediatric practice. Mainte- one place at any one time. nance of a film store, with its associated lighting, heating • Image retrieval is infinitely quicker from PACS than it is and cleaning, and the value of the physical space itself, using conventional film where someone physically has to is particularly costly in hospitals located in cities where go and fetch the film packet2. the space is at a premium. Even off-site film storage at • The benefits of a computerized system mean that all images a cheaper location is worth introducing as a cost-saving correctly and permanently reside under the appropriate measure in such institutions in the early years after PACS CChh0011--FF00116633..iinndddd 44 66//2288//0077 11::1100::2211 AAMM

Description:

Now published in 2 volumes, the new edition of this landmark text gives you a succinct but comprehensive account of all currently available imaging modalities and their clinical applications. Extensively revised and restructured, it is an excellent review text for resident radiologists, offering det