Books on the topic 'MRI-only'

MRI-guided breast biopsy techniques were developed to sample indeterminate and suspicious breast lesions visible only on MRI. Breast MRI performed for high-risk screening, problem solving, or assessment of extent of disease in patients with newly diagnosed breast cancer may demonstrate indeterminate findings, such as enhancing foci, masses or non-mass enhancement. If the lesion is not visible by mammography or ultrasound, and MRI follow-up is not appropriate, then MRI-guided biopsy is indicated. This chapter, appearing in the section on interventions and surgical changes, reviews the key points and procedural protocols and pitfalls for performance of magnetic resonance imaging (MRI)–guided breast core biopsy. Pre-, peri-, and post-procedure clinical management, radiology–pathology correlation, and imaging follow-up are also reviewed.

In general, ultrasonography and magnetic resonance imaging (MRI) are not associated with maternal or fetal risks and are the imaging techniques of choice for the pregnant patient. Ultrasound is the mainstay of obstetric imaging because it is safe and easily performed. However, MRI is becoming more useful as an adjunct in cases of questionable ultrasound findings or if additional information is needed to plan patient care. MRI lacks the potential risks of ionizing radiation associated with other forms of imaging and, when needed, gadolinium can be used (however, use remains uncommon in current practice). For maternal evaluation in patients with neuromuscular disorders MRI is ideal for imaging. Nevertheless, any imaging (either maternal or fetal) should be used only when needed. Furthermore, if other imaging modalities (CT, MRI with contrast, etc.) are better for assessing the mother’s or fetus’s condition and the information will influence the pregnancy care, these should be utilized.

Imaging techniques play a major role in managing patients with acute severe neurological signs. Initial evaluation of patients with traumatic brain injuries is best performed with a computed tomography (CT) scan, both for its ability to demonstrate most of the significant lesions and for logistical reasons. Magnetic resonance imaging (MRI) is able to provide more subtle information, as well as prognosis indicators, but is impractical until the patient’s condition has been stabilized. MRI has the same advantages for assessing anoxic brain injuries. In strokes, MRI has become the technique of choice, as it is able to highlight new lesions among older ones, and can identify ischaemic lesions only a few minutes after the event. At the same time MRI can identify or exclude contraindications for intravenous thrombolysis. Subarachnoid haemorrhages are best initially assessed with CT followed by a digital suppression angiogram to identify arterial aneurysms or arteriovenous malformations. In spine imaging, CT scan works the best in indicating traumatic bone lesions, while MRI is unsurpassed in examining the spinal cord and ligamentous injuries, and can provide prognostic indicators of the expected functional outcome.

Imaging techniques play a key role in the assessment of patients with the idiopathic inflammatory myopathies (IIM). Magnetic resonance imaging (MRI) can reveal muscle inflammation similarly to muscle scintigraphy and 18F-Fluorodeoxyglucose positron emission tomography, but is also able to visualize findings of chronic muscle damage such as muscle atrophy or fat replacement. Ultrasonography has a more limited role because it can only depict the superficial muscle layers. Imaging findings are not specific to IIM, but in the appropriate clinical context they support the diagnosis. MRI is also useful to target biopsy to affected muscles, thus increasing biopsy yield. In addition, because different myopathies present with different patterns of muscle involvement, imaging studies can provide differential diagnostic clues. Finally, imaging studies—especially MRI—can be used to monitor the effects of treatment by serially evaluating changes in muscle inflammation and damage.

Axial spondyloarthritis (axSpA) is a potentially disabling chronic inflammatory disease affecting the spine and sacroiliac (SI) joints. Lead symptoms are chronic back pain and stiffness. The disease is called radiographic axSpA or ankylosing spondylitis (AS) when, on plain radiographs, bone changes consistent with sacroiliitis are present. When no evidence of sacroiliitis is seen on radiographs, it is called non-radiographic axSpA. In such cases, diagnosis is made based on evidence of active inflammation of SI joints on magnetic resonance imaging (MRI) and clinical and laboratory features, or a combination of clinical and laboratory features only. Apart from affecting the spine and SI joints, axSpA may involve peripheral joints (e.g. knee, ankle) and manifest in extra-articular manifestations, for example uveitis, psoriasis, and inflammatory bowel disease. In this chapter, diagnosis and classification of axSpA is discussed, including use of MRI in detecting sacroiliitis and the difference between clinical diagnosis and disease classification.

Case History—A 78 yr old woman presenting with brainstem signs following a seizure.Brainstem syndromes typically cause ipsilateral cranial nerve lesions and contralateral long tract signs. They are commonly due to brainstem ischaemia, but can also be caused by neoplasia, demyelination, infective and hamartomatous lesions. Imaging, ideally with MRI rather than CT, is obligatory and only then—and possibly following other investigations to identify systemic abnormality or cerebrospinal fluid changes—can appropriate therapy be introduced....

Electroencephalography (EEG) combined with transcranial magnetic stimulation (TMS) provides detailed real-time information about the state of the cortex. EEG requires only two to four electrodes and can be a part of most TMS studies. When used with magnetic resonance imaging (MRI) based targeting and conductor modelling, the TMS-EEG combination is a sophisticated brain-mapping tool. This article explains the mechanisms of TMS-evoked EEG. It describes the technique of recording TMS evoked EEG and the possible challenges for the same. Furthermore, it describes possible solutions to these challenges. By varying the TMS intensities, interstimulus intervals, induced current direction, and cortical targets, a rich spectrum of functional information can be obtained. Cortical excitability and connectivity can be studied directly by combining TMS with EEG or other brain-imaging methods, not only in motor, but also nonmotor, areas.

Radial scars are benign lesions of the breast characterized pathologically by a fibroelastic core containing entrapped ducts and lobules that radiate outwards in a stellate pattern. This chapter, highlighting radial scar as a cause of architectural distortion, reviews its imaging features and differential diagnosis on mammography, digital breast tomosynthesis, ultrasound, and MRI; its diagnostic workup using multiple modalities; and its histological confirmation with image-guided core needle biopsy. The particular challenge of radial scar presenting as architectural distortion seen only with tomosynthesis is discussed, along with an algorithm for imaging evaluation and biopsy guidance in this setting. As radial scar, which is histologically related to complex sclerosing lesion and radial sclerosing lesion, is considered a high-risk lesion, management recommendations are also reviewed.

Isolated left ventricular non-compaction is a controversial entity which has only been reported in the past 30 years. It is becoming more frequently diagnosed due to the use of echocardiography and MRI. It can present in fetal life, infancy, childhood, and adult life. Clinically, the patient can present with cardiac arrhythmias, cardiac failure, systemic emboli due to thrombosis within the ventricles, and sudden death. It can be a genetic entity associated with mutations in many genes associated with hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy. It is a rare entity found at autopsy and is more common in children than adults. In the past the prognosis has been considered worse in children then in adults. Treatment is usually empirical, dealing with the cardiac failure, arrhythmias, and thromboemboli.

High praise continues to come in for the 4th volume of Jake Van Dyk's The Modern Technology of Radiation Oncology. From Peter Metcalfe in Physical and Engineering Sciences in Medicine… "Thank goodness medical physics has Jacob Van Dyk. Like Tiger Woods and Phil Mickelson in golf, his textbooks continue to make major comebacks. He has managed to assemble the most talented among us to sustain the up-to-date knowledge that is essential to our profession. Reference knowledge from this textbook will help ensure the medical physics profession is at the cutting edge of cancer research and clinical treatment. This textbook has taken pride of place on my bookshelf, right next to my most treasured Porsche magazines. I could not give it a higher accolade than that." From Rajesh A. Kinhikar in Journal of Medical Physics…"This resourceful book has aimed to serve as a comprehensive textbook for the practicing radiotherapy professionals. I would like to congratulate the authors and the Editor for such a high?quality scientific feast and strongly recommend the fourth volume of The Modern Technology of Radiation Oncologyto the clinical medical physicists and radiation oncology professionals involved with the rapidly evolving radiotherapy." New topics addressed in volume 4 include surface-guided radiation therapy (RT), PET/MRI, real-time MRI guidance, robust optimization, automated treatment planning, artificial intelligence, adaptive RT, machine learning, big data, radiomics, particle therapy RBE, nanoparticle applications, economic considerations, global medical physics activities, global access to RT, and FLASH RT. The volumes in this series have not only been valued by medical physicists and radiation oncologists in clinical practice around the world, but have also provided an important learning resource for residency programs, radiation technologists, dosimetrists, research students, biomedical engineers, and ancillary professionals related with radiotherapy. Administrators and scientists affiliated with the practice of radiation therapy will also find this book a useful resource.

During the 1960s and 1970s, new diagnostic technologies were developed that provided unique visual information about the heart’s structure and function. Echocardiography uses ultrasound to create moving images of the heart’s walls and valves. During the 1980s, advances in computer technology contributed to the development of new ultrasound techniques (such as two-dimensional echocardiography) that provided better visualization of the heart. Doppler echocardiography yielded physiological information that had been available previously only by performing cardiac catheterization. Mayo helped pioneer several echocardiography innovations, which it popularized in many publications and lectures. Another so-called noninvasive approach to imaging the heart involved the use of radioisotopes. Nuclear cardiology proved to be especially useful in evaluating patients with known or suspected coronary artery disease. The application of CT and MRI imaging to the heart lagged because it was difficult to apply these technologies to a moving organ.

Functional neuroimaging techniques include methods that probe various aspects of brain function and help derive models of brain organization in health and disease. These techniques can be grouped in two categories. Some are mainly based on electromagnetic signals (electroencephalography, magnetoencephalography), recording brain activity using a large number of sensors with exquisite temporal resolution (usually of the order of a kilohertz) but allowing only indirect characterization of three-dimensional brain activity by resorting to mathematical models. The second type includes different techniques (PET scan, SPECT, MRI, optical imaging) that typically assess metabolic or hemodynamic parameters, with millimeter spatial resolution and usually from the entire brain volume. However, temporal resolution is usually low because it is primarily driven by metabolic processes that unfold in several seconds or minutes. This chapter focuses on this second type, covering the contribution of brain imaging to understanding NREM sleep and REM sleep and also sleep disorders.

Tumours of the central nervous system examines the epidemiology, aetiology, genetics and pathology of these heterogeneous tumours. Clinical presentation reflects the site of origin and rate of growth. Investigation usually comprises imaging (MRI superior to CT for most), and biopsy; requirement for additional staging depends on pathology. The treatment of low-grade gliomas may be delayed if small with few symptoms, otherwise surgery and/or radiotherapy. High grade gliomas may be managed with surgery, radiotherapy, and temozolomide chemotherapy in fit patients. Unfit patients should be offered supportive care only. Brief summaries are provided for management of ependymoma, pineal tumours, meningioma, germ-cell CNS tumours, pituitary tumours, CNS lymphoma, acoustic neuroma, medulloblastoma, and spinal cord tumours. Radiotherapy for primary CNS tumours is described along with its side effects, and chemotherapy for these diseases is reviewed. Brain metastases far outnumber primary brain tumours, with generally poor prognosis, but this relates both to the pathology and patient performance status. Appropriate treatment may include surgery, radiotherapy, and/or chemotherapy.

Non-traumatic spinal cord disease may be caused by compression due to tumour, infection or haematoma, inflammation, infection or post-infection, metabolic disturbances, infarction, and degeneration. The diagnosis is often made easier by the clinical assessment: the patient’s age, the speed of onset of the disease, severity of the deficits, the pattern of motor and sensory involvement, and presence of pain and sphincter symptoms are all important in making an assessment of the site and likely nature of the spinal disease.Investigations are obligatory to confirm a diagnosis and to direct therapy. MRI is the most useful investigation. It has largely replaced myelography which should now only be considered in patients with indwelling cardiac pacing wires. Additional investigations including examination of the cerebrospinal fluid, evoked potentials, and specific blood tests may be required and the value of plain X-rays, CT scan, and, in some instances, angiography should not be overlooked.The remainder of this chapter will consider specific disorders, identifying pathology, clinical presentation, investigation, and management. Acute and chronic conditions are considered separately and those affecting the cauda equina, spinal root, and sphincters are considered in Chapter 29.

Ankylosing spondylitis (AS) is a chronic inflammatory disease predominantly of the sacroiliac joint (SIJ) and the spine. It starts normally in the second decade of life and has a slight male predominance. The prevalence is between 0.2 and 0.8% and is strongly dependent on the prevalence of HLA B27 in a given population. For the diagnosis of AS, the presence of radiographic sacroiliitis is mandatory. However, radiographs do not detect active inflammation but only structural bony damage. Most recently new classification criteria for axial spondyloarthritis (SpA) have been developed by the Assessement of Spondylo-Arthritis international Society (ASAS) which cover AS but also the earlier form of non-radiographic axial SpA. MRI has become an important new tool for the detection of subchondral bone marrow inflammation in SIJ and spine and has become increasingly important for an early diagnosis. HLA B27 plays a central role in the pathogenesis but its exact interaction with the immune system has not yet been clarified. Besides pain and stiffness in the axial skeleton patients suffer also from periods of peripheral arthritis, enthesitis, and uveitis. New bone formation as a reaction to inflammation and subsequent ankylosis of the spine determine long-term outcome in a subgroup of patients. Currently only non-steroidal anti-inflammatory drugs (NSAIDs) and tumour necrosis factor (TNF) blockers have been proven to be effective in the medical treatment of axial SpA, and international ASAS recommendations for the structured management of axial SpA have been published based on these two types of drugs. Conventional disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate are not effective.

Psoriatic arthritis (PsA) is much more than just joint disease. Although previous clinical classifications have categorized by pattern of joint involvement and axial disease, imaging techniques such as MRI and ultrasound have demonstrated that not only are many more joints involved but also a wide variety of adjoining tissues. The concept of enthesitis is evolving and high resolution imaging studies are demonstrating involvement of tissues beyond just the enthesis. Many investigators have chosen to use sonographic entheseal systems designed for Spondyloarthritis in general which may not be appropriate and may lead to excess confounding by obesity. Inclusion of entheses that seem more relevant to PsA may improve the validity and specificity of the sonographic outcome tool. Nail affliction is associated with PsA, as well as enthesitis. Sonography is able to demonstrate the nail apparatus. More recent pathoanatomic findings may help explain the close link with enthesitis. Synovitis in PsA is often involved with inflammation and alteration of neighbouring structures such as the extensor tendons, palmar or plantar plates. Some investigators have proposed that inflammation in PsA may start at the entheseal sites and then spread to the joint. Dactylitis epitomizes the concept of multiple tissues involved in the digit giving rise to the clinical appearance of a uniformly swollen digit. Sonography can image many of these tissues in high resolution and offer insights into the pathophysiology of dactylitis.

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease predominantly of the sacroiliac joint (SIJ) and the spine. It starts normally in the second decade of life and has a slight male predominance. The prevalence is between 0.2% and 0.8% and is strongly dependent on the prevalence of HLA-B27 in a given population. AxSpA can be split in patients with radiographic axSpA (also termed ankylosing spondylitis (AS)) and in patients with non-radiographic axSpA (nr-axSpA). For the diagnosis of AS, the presence of radiographic sacroiliitis is mandatory. However, radiographs do not detect active inflammation but only structural bony damage. Most recently new classification criteria for axSpA have been developed by the Assessment of Spondylo-Arthritis International Society (ASAS) which cover AS but also the earlier form of nr-axSpA. MRI has become an important new tool for the detection of subchondral bone marrow inflammation in SIJ and spine and has become increasingly important for an early diagnosis. HLA-B27 plays a central role in the pathogenesis but its exact interaction with the immune system has not yet been clarified. Besides pain and stiffness in the axial skeleton patients suffer also from periods of peripheral arthritis, enthesitis, and uveitis. New bone formation as a reaction to inflammation and subsequent ankylosis of the spine determine long-term outcome in a subgroup of patients. Currently only non-steroidal anti-inflammatory drugs (NSAIDs) and tumour necrosis factor (TNF) blockers have been proven to be effective in the medical treatment of axial SpA, and international ASAS recommendations for the structured management of axial SpA have been published based on these two types of drugs. Conventional disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate are not effective.

The term functional has almost replaced psychogenic in the neuromuscular literature for two reasons. It implies a disturbance of function, not structural damage; therefore, it defies laboratory testing such as MRIS, electromyography (EMG), and nerve conduction study (NCS). It is convenient to draw a parallel to the patients between migraine and brain tumors, as both cause headache, but brain MRI is negative in the former without minimizing the suffering of the patient. It is a “software” and not a “hardware” problem. It avoids irritating the patient by misunderstanding the word psychogenic which to many means “madness.”The cause of this functional impairment may fall into one of the following categories:• Conversion reaction: conversion of psychological stress to physical symptoms. This may include paralysis, hemisensory or distal sensory loss, or conversion spasms. It affects younger age groups.• Somatization: chronic multiple physical and cognitive symptoms due to chronic stress. It affects older age groups.• Factions disorder: induced real physical symptoms due to the need to be cared for, such as injecting oneself with insulin to produce hypoglycemia.• Hypochondriasis: overconcern about body functions such as suspicion of ALS due to the presence of rare fasciclutations that are normal during stress and after ingestion of a large amount of coffee. Medical students in particular are targets for this disorder.The following points are to be made on this topic. FNMD should be diagnosed by neuromuscular specialists who are trained to recognize actual syndrome whether typical or atypical. Presentations that fall out of the recognition pattern of a neuromuscular specialist, after the investigations are negative, they should be considered as FNMDs. Sometimes serial examinations are useful to confirm this suspicion. Psychatrists or psychologists are to be consulted to formulate a plan to discover the underlying stress and to treat any associated psychiatric disorder or psychological aberration. Most patients think that they are stressed due to the illness and they fail to connect the neuromuscular manifestations and the underlying stress. They offer shop around due to lack of satisfaction, especially those with somatization disorders. Some patients learn how to imitate certain conditions well, and they can deceive health care professionals. EMG and NCS are invaluable in revealing FNMD. A normal needle EMG of a weak muscles mostly indicates a central etiology (organic or functional). Normal sensory responses of a severely numb limb mean that a lesion is preganglionic (like roots avulsion, CISP, etc.) or the cause is central (a doral column lesion or functional). Management of FNMD is difficult, and many patients end up being chronic cases that wander into clinics and hospitals seeking solutions and exhausting the health care system with unnecessary expenses.It is time for these disorders to be studied in detail and be classified and have criteria set for their diagnosis so that they will not remain diagnosed only by exclusion. This chapter will describe some examples of these disorders. A video clip can tell the story better than many pages of writing. Improvement of digital cameras and electronic media has improved the diagnosis of these conditions, and it is advisable that patients record some of their symptoms when they happen. It is not uncommon for some Neuromuscular disorders (NMDs), such as myasthenia gravis (MG), small fiber neuropathy, and CISP, to be diagnosed as functional due to the lack of solid physical findings during the time of the examination. Therefore, a neuromuscular evaluation is important before these disorders are labeled as such. Some patients have genuine NMDs, but the majority of their symptoms are related to what Joseph Marsden called “sickness behavior.” A patient with carpal tunnel syndrome (CTS) may unconsciously develop numbness of the entire side of the body because he thinks that he may have a stroke.