Special boxes draw attention to important information in the chapter. List of pharmaceutical resources is included in new appendix. End-of-chapter questions include 10 multiple-choice questions for self-assessment. Chapter objectives focus on the most important information to be learned. Updated art program includes new line drawings, diagnostic images, and equipment photographs. New content includes: Positron emission tomography MR angiography Peripheral angiography and venography Left heart cardiac catheterization Monitoring procedures and equipment during cardiac catheterization Extensive additions to the vascular procedures sections, including: Revascularization Thrombolytic therapy Ablation Embolization Transcatheter biopsy Transjugular intrahepatic portosystemic shunts Inferior vena cava filters Information abut HIPAA.
Fully revised, second edition bringing trainees and physicians fully up to date with the latest developments and rapidly changing concepts in the field of paediatrics.
Neuroimaging provides a valuable noninvasive window into the human neural system and is used in fundamental and clinical research. Imaging techniques are essential for understanding spontaneous neural activity and brain mechanisms engaged in the processing of external inputs, memory formation, and cognition.
Modern imaging modalities make it possible to visualize memory processes within the brain and to create images of its structure and function. Scientists and technologists are joining forces to pave the way for improving imaging technologies and methods, data analysis, and the application of imaging to investigate the wide spectra of neurological diseases, neuropsychological disorders, and aging.
Imaging techniques are essential for the identification of biological markers of the earliest stages of neurodiseases and the development of new therapies. This book intends to provide the reader with a short overview of the current achievements in the state-of-the-art imaging modality methods, their highlights, and limitations in neuroscience research and clinical applications.
The current state of in-vivo neuroimaging methods in the context of the understanding and diagnosis of mental disorders and relation to the mind is also discussed in a modern compact format, featuring the latest and most relevant research results. This textbook provides a practically applicable resource for understanding the surgical oncology management of pancreatic cancer. It discusses relevant aspects of anatomy and pathophysiology along with the latest diagnostic techniques.
Insightful descriptions are then provided detailing how to perform critical surgical procedures when treating these patients. Relevant perioperative management strategies and emerging themes in cancer biology critical to understanding and treating the disease are also described. The need for cross-discipline collaboration to facilitate and enhance innovation within the discipline is reinforced throughout the text.
Textbook of Pancreatic Cancer: Principles and Practice of Surgical Oncology is a detailed work covering the basic material important to trainees as well as advanced curriculum for established specialists in the field from a multi-disciplinary perspective. Therefore, it is crucial resource for all practicing and trainee professionals who encounter these patients in their day-to-day clinical practice.
Combines clinical images, full-color illustrations and bulleted text to create a comprehensive, up-to-date resource for learning and review.
This book presents applications of machine learning techniques in processing multimedia large-scale data. Roth presents comprehensive guidance on body imaging—from the liver to the female pelvis—and discusses how physics, techniques, hardware, and artifacts affect results. Christopher Roth and Sandeep Deshmukh, covers the essential concepts residents, fellows, and practitioners need to know, laying a solid foundation for understanding the basics and making accurate diagnoses.
This edition includes new imaging techniques and information on the liver, the kidney, and nephrogenic syndrome"--Provided by publisher. With a focus on the basic imaging principles of breast MRI rather than on mathematical equations, this book takes a practical approach to imaging protocols, which helps radiologists increase their diagnostic effectiveness. While there are several excellent texts covering the fundamentals of body MRI , the teaching file format appeals to It describes how relaxation mechanisms help predict tissue contrast and how an MR signal is localized to a selected slice through the body.
The text then focuses on frequency and phase encoding. The axial T2-weighted image A demonstrates focal hyperintense From Roth C, Deshmukh S. Fundamentals of Body MRI , ed 2.
It walks the reader through the basics of MRI, making it especially accessible to beginners. From a detailed outline of equipment prerequisites for obtaining high quality breast MRI to instructions on how to optimize image quality, expanded discussions on how to obtain optimized dynamic information, and explanations of good and bad imaging techniques, the book covers the topics that are most relevant to performing breast MRI.
Cases presented in this book include common and uncommon diseases of nearly every organ system of the abdomen and pelvis. Each case succinctly discusses the relevant imaging findings, differential diagnosis, and potential imaging and diagnostic pitfalls. Many cases also include discussion of MRI technique, with illustration of some common artifacts. For radiology residents and fellows, this book will be a valuable study tool and reference; fourth-year residents should find this book especially helpful when studying for oral boards.
Practicing radiologists should find this a useful quick review of state-of-the-art body MRI. After covering background mathematics, physics, and digital imaging, the book presents fundamental physical principles, including magnetization and rotating reference frame. It describes how relaxati. This new title solves the "information overload" problem often faced by trainee and practicing radiologists by emphasizing the essential knowledge you need in an easy-to-ready hybrid format of traditional text and bullet points.
Emphasizes a "just the essentials" approach to foundational abdominal imaging content presented in an easy-to-read, quick reference format, with templated content that includes numerous outlines, tables, pearls, boxed material, and bulleted text for easy reading and efficient recall. Prioritizes high-yield topics and explains key information to help you efficiently and effectively prepare for board exams.
Includes reporting tips and recommendations with sample structured reports. Introductory chapters provide readers with the fundamental scientific concepts underlying the medical use of imaging modalities and technology, including ultrasound, computed tomography, magnetic resonance imaging, and nuclear medicine. Highly illustrated with images and diagrams, each chapter in Radiology Fundamentals begins with learning objectives to aid readers in recognizing important points and connecting the basic radiology concepts that run throughout the text.
Fundamentals of Pediatric Imaging, Third Edition presents the foremost techniques of pediatric medical image analysis and processing. It includes advanced imaging techniques, neuro applications, and highlights basic anatomy needed to understand this complex specialty.
The book introduces the theory and concepts of pediatric digital image analysis and newly revised information on quality and safety topics, imaging modalities, imaging applications, and new discoveries in diseases and treatments.
The newly revised edition provides updates in areas of expertise including neurologic, musculoskeletal, cardiac, chest, and GU imaging. Edited by Lane F. Includes over high-quality digital images clearly demonstrating essential concepts, techniques, and interpretation skills Discusses advanced MR imaging topics such as MR enterography, MR urography, and cardiac CT and MRI Contains reader-friendly lists, tables, and images for quick and easy referencing Includes imaging modalities, imaging applications, and new discoveries in diseases and treatments.
A clear, concise, yet comprehensive text covering the fundamentals and nuances of performing and interpreting high-quality GI and GU fluoroscopy. This fifth edition of the most accessible introduction to MRI principles and applications from renowned teachers in the field provides an understandable yet comprehensive update.
Accessible introductory guide from renowned teachers in the field Provides a concise yet thorough introduction for MRI focusing on fundamental physics, pulse sequences, and clinical applications without presenting advanced math Takes a practical approach, including up-to-date protocols, and supports technical concepts with thorough explanations and illustrations Highlights sections that are directly relevant to radiology board exams Presents new information on the latest scan techniques and applications including 3 Tesla whole body scanners, safety issues, and the nephrotoxic effects of gadolinium-based contrast media.
This landmark reference provides the most complete coverage of magnetic resonance imaging of the abdomen and pelvis, with particular emphasis on illustrating benign, malignant, and inflammatory lesions. Organized by anatomic region, the text presents brief descriptions of pathophysiology followed by detailed discussion of characteristics of the relevant organ or system. Extensively updated and revised throughout, the new third edition includes over 2, figures, of which more than are all-new, including over 3T images presented throughout the organ systems.
Previously known as the Textbook of Uroradiology, the newly retitled Genitourinary Radiology continues to bring you top-flight expertise in interpreting imaging studies of the genitourinary tract.
The result remains an indispensable resource for diagnosing genitourinary diseases and disorders. Magnetic resonance imaging MRI is a technique used in biomedical imaging and radiology to visualize internal structures of the body. Because MRI provides excellent contrast between different soft tissues, the technique is especially useful for diagnostic imaging of the brain, muscles, and heart. In the past 20 years, MRI technology has improved significantly with the introduction of systems up to 7 Tesla 7 T and with the development of numerous post-processing algorithms such as diffusion tensor imaging DTI , functional MRI fMRI , and spectroscopic imaging.
From these developments, the diagnostic potentialities of MRI have improved impressively with an exceptional spatial resolution and the possibility of analyzing the morphology and function of several kinds of pathology. Given these exciting developments, the Magnetic Resonance Imaging Handbook: Image Principles, Neck, and the Brain is a timely addition to the growing body of literature in the field. Although prostate cancer is the second leading cause of cancer death in men in the USA, it can be treated successfully if detected early.
Disease management has gradually changed to a paradigm that relies on close monitoring through active surveillance in select patients, as well as ongoing refinements in treatment interventions, including minimally invasive procedures.
This has resulted in a critical need for a more exacting methodology for performing targeted biopsies, assessing risk levels, and devising treatment strategies. Prostate MRI has emerged as the most precise, state-of-the-art imaging modality for prostate cancer diagnosis and management, thereby creating an immediate demand for radiologists to become proficient in its use.
Magnetic resonance imaging MRI system schematic. The purpose of the Fourier transform is to translate the k-space data in the frequency and phase domain into image data with spatial coordinates. The numeric value assigned to each Fourier transform—solved pixel corresponds to the MR signal amplitude, or signal. Spin-echo and gradient-echo pulse sequences. TE, time to excitation. The frequency-encoding gradient dephases the excited spins i.
Of course, these pulse sequences usually need to be repeated multiple times in order to acquire enough data to fill k space for a single image. The interval between Rf excitation pulses is referred to as TR time to repetition. In the GE experiment, the refocusing pulse is omitted and a frequency-encoding rephasing lobe of reversed polarity reestablishes phase coherence. Advantages and disadvantages of each technique must be acknowledged when devising MRI protocols.
In the end, spectral considerations dictate the use of these two types of pulse sequences. The increased time required to obtain T2-weighted sequences demands a longer acquisition time which is discussed in more detail later , conforming to the specifications of the SE sequence.
Multiecho spin-echo and gradient-echo pulse sequence diagrams. In the case of the SE sequence, multiple refocusing pulses follow the Rf excitation pulse, each producing an echo Fig. The extreme example of this multiecho technique is the SSFSE sequence in which all echoes necessary to fill k space for a given image are acquired after a single excitation pulse. The FSE sequence includes at least two and less than all of the refocusing pulses and echoes necessary to fill k space; acquisition time and susceptibility artifact resistance of an FSE sequence are greater than a conventional SE sequence and less than an SSFSE sequence.
The basic premise of a 3-D pulse sequence is the excitation of a volume of tissue instead of a slice. Rather than covering the region of interest ROI with individual contiguous slices, the ROI is covered with a single volume. Instead of acquiring multiple images independently, the 3-D technique acquires the volume data set all at once. During 3-D image acquisition, the rephasing lobe of the slice-select gradient serves as a phase-encoding gradient in the slice axis, thereby encoding z-axis spatial information into the excited volume.
Using 3-D k-space filling techniques, each Rf pulse excites the entire volume of tissue rather than a single slice , magnifying SNR compared with 2-D techniques. Consequently, 3-D sequences yield higher SNRs, permitting the partition of the data into smaller fragments, or voxels, generating higher spatial resolution and image detail.
Rf excitation and T1 recovery and T2 decay. NMV, net magnetic vector; TE, time to excitation. The behavior of a proton in a magnetic field varies depending on its unique microenvironment. For all intents and purposes, the protons relevant to MR imaging are hydrogen 1H protons.
These differences are exploited in MRI with the use of targeted pulse sequences with characteristic parameters. At this point, the longitudinal component of the vector is minimized and the transverse component is maximized. Regaining, or recovering, longitudinal magnetization is referred to as T1 relaxation Mz Mxy T2 decay T1 recovery 0. T1 and T2 relaxation curves and values for different tissues.
However, premise fails. Whereas these values usually approximate that rule— that is, spins with long T2 values also have long T1 values—they do not always directly follow one another. T2 decay generally outpaces T1 recovery and the T1 relaxation rate of a proton defines the potential upper limit of the T2 decay time Fig.
T1 values at different Tissue 0. The T1 value of a proton defines its ability to release energy and return to its original state. This is another counterintuitive principle—stronger magnetic field strength would seem to draw spins back to equilibrium faster. Suspend that notion and remember that T1 relaxation depends on the internal structure of the proton. T2 values are not affected by magnetic field strength. T2 values also decrease with structural organization facilitating the dissipation of energy.
The T2 value measures the length of time that transverse magnetization remains coherent. In other words, after the Rf excitation pulse, the NMV is deflected into the transverse plane, at which time all spins are in phase.
Under these circumstances, all spins yield signal regardless of their T1 and T2 values Fig. Therefore, signal generated from this pulse sequence represents a map of proton density—hence, the designation proton density PD. A, T1 contrast mechanism. B, T2 contrast mechanism. TR, time to repetition. Parenthetically, another method of achieving T1-weighting involves modifying the flip angle FA.
Increasing the FA increases the amount of—and time for—longitudinal magnetization to be recovered before the next Rf excitation pulse. Only spins with short T1 values recover enough longitudinal magnetization to be excited into the transverse plane and avoid saturation.
Inversion recovery pulse sequence. B0 This sequence of events exemplifies saturation. Spins with short T2 values experience rapid loss of transverse magnetization with little to no residual signal at the time the echo is sampled TE see Fig.
Maintaining a long TR ensures that spins with long T1 values which usually characterize spins with long T2 values will not be saturated. This pulse sequence scheme—T2-weighting—therefore ensures that signal yield primarily results from spins with long T2 values. A few pulse sequence modifications bear consideration in order to explain the ability to selectively image protons in body MRI: the spectrally selective pulse, the inversion pulse, and chemical shift. Thereafter, the Rf excitation pulse is applied in the absence of signal contribution from fat protons.
This type of inversion recovery pulse sequence is known as the STIR short tau inversion recovery sequence. Changing the TI targets protons with different T1 relaxation rates. This technique is usually applied to brain imaging, and is known as the FLAIR fluid attenuation inversion recovery sequence. The most popular practical application of this phenomenon is fat-water chemical shift imaging—colloquially referred to as in- and out-of-phase imaging.
Echoes are timed to coincide with out-of-phase and in-phase timepoints of the relevant spins Fig. In the case of fat and water protons at 1.
Therefore, after an Rf excitation pulse, echoes acquired at 2. Decreasing the TR isolates signal from protons with short T1 values, whereas increasing the TE isolates signal from protons with long T2 values.
T1- and T2-weighted sequence design follows these parameter prescriptions. Fat saturation techniques supplement pulse sequences to eliminate signal from lipid protons, isolating signal from the remaining protons. Spectrally selective and inversion recovery techniques are commonly used methods.
Fat-water chemical shift imaging is used to identify the coexistence of these protons by synchronizing echoes with the out-of-phase and in-phase precessional timepoints.
Chemical shift imaging. Rf, radiofrequency; TE, time to excitation. Each pulse sequence is designed with a tissue-specific objective in mind, which necessitates a familiarity of the different tissues encountered see Fig.
The two major categories of protons encountered in body MRI—water and fat protons—require further subdivision to generate a rational pulse sequence scheme. Water protons split into two major categories: bound water and free water protons.
Out-of-phase imaging shows microscopic fat. The marked signal loss in the liver on the out-of-phase image A compared with the in-phase image B indicates the presence of microscopic fat. Acquired with OOP as single dual-echo acquisition Pre-contrast Paramagnetic substances blood, melanin, etc. Body MRI pulse sequences. Free extracellular water protons exist in solution e. Microscopic fat infiltrates solid organs such as the liver and certain tumors such as hepatic adenomas and renal cell carcinoma.
A third category includes substances with magnetic susceptibility. Magnetic susceptibility describes the tendency of a substance to become magnetized in a magnetic field. Paramagnetic substances enhance the efficiency of T1 and T2 relaxation.
Relevant paramagnetic substances include methemoglobin present in hemorrhage , melanin, protein, and gadolinium. Iron, cobalt, and nickel are examples of ferromagnetic substances.
MRI pulse sequences each generally target one or more of these substances. T1-weighted sequences usually include an in- and out-of-phase sequence, a pre- and postcontrast dynamic sequence and a delayed postcontrast sequence.
T1-weighted sequences evoke signal from substances with short T1 values, such as fat and protons experiencing paramagnetic effects e. The data are subsequently separated into two image sets covering the same anatomy. This sequence is designed to detect enhancement, or the paramagnetic effect of gadolinium. The sequence parameters are adjusted to detect the T1-shortening effects of administered gadolinium.
The postcontrast phases of the dynamic sequence usually include an arterial phase, a portal venous phase, and occasionally, a venous phase. The delayed postcontrast sequence usually mirrors the parameters of the dynamic sequence. The timing of the delayed sequence most closely approximates the delivery of contrast to the interstitium. The dynamic sequence precedes delivery of gadolinium to the interstitium and exhibits no enhancement.
Consequently, fibrous tissue and interstitial edema i. Whereas T1-weighted sequences used in body MRI are usually GE sequences, the T2-weighted sequences are mostly SE-based sequences, removing consideration of chemical shift and susceptibility phenomena.
SE sequences are better adapted to the needs of T2-weighting for most applications. T2-weighted SE pulse sequences used in body MRI benefit from the refocusing pulse, which eliminates potentially prohibitive susceptibility artifact and also helps to preserve SNR.
T2-weighted sequences differ chiefly in their targeted water molecule—free water versus bound water. The main difference between these sequences is the TE. A relatively lower TE is adapted to identify differences in bound water content between solid tissues. Increasingly higher TE values more selectively isolate signal from free water protons and eliminate signal from solid tissues.
The moderately T2-weighted sequence approximates the T2 values of solid organs, such as the liver. In-phase imaging shows susceptibility artifact. C, The artifact on the corresponding single-shot fast spin-echo SSFSE image is better controlled owing to the refocusing pulses despite the much longer TE. D, Susceptibility artifact also arises from endogenous structures, such as gas-containing bowel, as seen in the out-of-phase image arrow in a different patient.
E, Blooming arrow is evidence on the susceptibility in-phase image. T2-weighted sequence used in abdominal imaging is 80 msec. This value optimizes the contrast between substances of different bound water content, such as normal parenchymal tissue and neoplasms, which typically harbor higher water content.
The bound water specificity justifies the name bound water sequence. Contrast between solid tissues with different bound water content decays compared with the moderately T2-weighted sequence, potentially obscuring solid lesions prompting the name lesion suppression sequence.
Dynamic pulse sequence schematic. Precontrast imaging shows paramagnetic substance. A, The precontrast fat-suppressed paramagnetic image in a patient with metastatic uveal melanoma shows multiple, variably hyperintense lesions arrows reflecting variable melanotic content. B, A paramagnetic image in a patient with pelvic pain shows a large, irregularly shaped lesion with significant paramagnetism arrow due to hemorrhage.
C, Marked hypointensity on the T2-weighted image characterizes the concentrated blood products found in an endometrioma arrow. D, A paramagnetic image in a different patient shows the paramagnetic effects of a small left renal hemorrhagic cyst thin arrow and enzymatic proteins in the pancreas thick arrows , causing these structures to be relatively hyperintense.
Delayed postcontrast imaging shows interstitial enhancement. A, The T2-weighted image reveals an unusual, large hypointense lesion involving the anterior abdominal wall arrows. Marked gradual enhancement—based on comparison between early postcontrast B and delayed postcontrast C —reflects the large interstitial space in a desmoid tumor with extensive fibrosis.
Moderately T2-weighted imaging shows bound water tissue contrast. A, The moderately T2-weighted image in a patient with a hepatic schwannoma arrow expresses the high water content often seen in schwannomas.
Note the relatively higher tissue water content of the spleen compared with the liver—reflected by relative hyperintensity—serving as an indication of the tissue contrast of the bound water sequence. B, Even the relatively unhydrated lymphomatous lesions thin arrows with periportal lymphadenopathy thick arrow in a different patient with disseminated lymphoma are conspicuous on the bound water sequence owing to the high tissue contrast.
By relatively isolating free water protons, this sequence deserves the title free water sequence. Heavily T2-weighted imaging shows free water. A and B, The heavily T2-weighted images depict free water protons preferentially, at the expense of solid tissue contrast.
Solid tissues with bound water molecules, such as the liver, lack signal, whereas structures with free water exhibit marked hyperintensity proportional to their water content. Pure free water molecules found in cerebrospinal fluid arrows , gastrointestinal contents thick arrows , gallbladder open arrow , and simple renal and hepatic cysts define maximum signal intensity, whereas lesions with intermediate free water content, such as hemangiomas dashed arrows appear moderately hyperintense.
Unlike most other body parts, continuous physiologic motion, variable quantities of paramagnetic substances, and variable patient body habitus frequently complicate the process.
Addressing these issues greatly improves image quality. Motion Motion artifact is a layered topic complicating every examination, especially in the abdomen. Motion induces a phase shift in a proton during the application of a magnetic field gradient.
There is no implicit correction algorithm in k space or the Fourier transform for the phase shift induced by motion. Consequently, the Fourier transform spatially misregisters moving protons. Within-view phase errors arise because a moving proton fails to be rephased by applied gradients. View-to-view phase errors result from signal amplitude variations resulting from motion between echoes, which results from bulk motion see Fig.
This happens under the circumstances of direct motion and pulsatile vascular flow. Physically replacing spins of different species explains the basis for this error in the case of direct motion.
Acquisition time depends on multiple parameters Fig. Within-view motion artifact. The NEX is usually already minimized. Motion artifact. A, The sagittal T2-weighted fat-suppressed image shows the effects of motion during image acquisition with phase misregistration of protons in the iliac vessels arrows portrayed by periodic superimposition across the phase axis—ghosting.
B, The same phenomenon thin arrows occurs along the phase-encoding axis on the corresponding axial image, which is accompanied by phase misregistration of bowel loops due to peristaltic motion thick arrows. C, Occasionally, this artifact simulates a pathologic lesion arrow. The appearance of this pseudolesion the pulsatile ghost of the aorta on multiple contiguous images and absence on other sequences resistant to artifact disclose the artifactual etiology.
D, Bulk motion from breathing also causes phase-encoding errors reflected by ghosting arrows. Strategies to minimize motion artifact. Careful attention to crop the phase-encoding FOV by reducing the phase-encoding matrix number of phase-encoding lines and include only relevant anatomy and not air surrounding the patient yields dividends in image acquisition time. Converting the default square FOV equal x and y dimensions to an asymmetrical phase-encoding minimized construct is termed rectangular FOV.
The solution is to increase the phase FOV. When implementing parallel imaging, the problem is exacerbated by the fact that wraparound artifact plots centrally rather than at the periphery of the image see Fig.
For this reason, parallel imaging demands greater attention to FOV considerations. Although theoretically wraparound artifact also plagues the frequency-encoding axis when sampled frequencies outside the sampled range are plotted into k space, digital filters eliminate these unwanted frequencies, obviating this problem.
Increasing the ETL also reduces scan time by economizing the utility of each Rf excitation pulse. For each applied Rf excitation pulse, the ETL defines the number of echoes acquired.
The SSFSE sequence exemplifies the utility of this technique by acquiring all echoes after a single Rf excitation pulse. Image blur is a potential unwanted side effect of long echo-train imaging. Each successive echo sampled during an echo train possesses a progressively longer TE. When combined to form a single image, the effect of the variable TE is suboptimal edge detection, or blur.
Rectangular field of view FOV. Parallel imaging uses the differential spatial profiles of the phased array coil elements to reduce k space filling. Undersampled, aliasing k space is unwrapped with mathematical equations using the various spatially dependent coil element sensitivities. The relative amount of coil spatial sensitivity information replacing unwrapping aliased k space is expressed through the coefficient R.
The geometry factor, g, measures the aliasing unwrapping proficiency of the coil arrangement. The acceleration factor R applied to parallel imaging describes the proportion of phaseencoding k-space lines filled per Rf excitation pulse.
So, an acceleration factor of 2 means that only half of the phase-encoding lines of k space must be filled using the echoes obtained from the pulse sequence. As a last resort, decreasing spatial resolution in the slice and phase axes diminishes scan time. By decreasing the image matrix in the phaseencoding direction, fewer phase-encoding steps are acquired, decreasing acquisition time, according to the previous equation.
Obtaining fewer slices translates to adding the sum of the acquisition time equation together fewer times i.
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