Magnetic resonance angiography of the pediatric abdomen and pelvis

Although abdominal and pelvic vascular disease is much less common in children than in adults, MR angiographic techniques widely used in adults can also be readily applied in the pediatric population with suspected vascular disease. MR techniques, equipment, and image analysis software are in a continual state of development and refinement. Given the advantages of MR angiography (i.e., its absence of ionizing radiation, capability to obtain images without iodinated contrast material, and limited invasiveness), the applications of MR angiography in the pediatric abdomen and pelvis are likely to continue to increase.     

Magnetic resonance imaging of the pediatric shoulder

Magnetic resonance (MR) imaging is a modality widely used to assess shoulder abnormalities in children. A thorough understanding of the development of the shoulder and adequate MR techniques are crucial in the radiologic evaluation. The immature skeleton is particularly vulnerable to insults such as trauma, infection, and inflammation, and responds in unique ways. The pediatric shoulder can also be affected by complex congenital deformities such as brachial plexus injuries. In addition, certain neoplasms can be seen specifically in the young patient. MR imaging plays a critical role in the initial diagnostic evaluation and in assessing posttreatment responses.     

Magnetic resonance imaging of the pediatric knee

Magnetic resonance imaging (MRI) is an excellent modality for imaging the pediatric knee because of its superb soft-tissue contrast, multiplanar capability, and lack of ionizing radiation. The knee is the most common joint imaged by MRI in the pediatric population. The majority of studies are performed on older children or adolescents with pain and/or known trauma. There are variations of injury and patterns of injury that are unique to children. The knee of a child also may be studied by MRI for other indications, including tumor, inflammatory disease, and developmental abnormalities. It is important to have a systematic approach to analysis of the knee MR images. Analysis should include individual attention to bones, articular cartilage, muscles and tendons, soft tissues, neurovascular bundle, joint space, fluid collections, ligaments, and menisci.     

Magnetic resonance imaging in pediatric stroke

Pediatric stroke is a term that can be used to encompass everything from hypoxic-ischemic injury to the fetal central nervous system, and especially the premature neonate, to bland versus hemorrhagic infarction from arterial or venous causes in the infant and older child. Pediatric stroke is a chronically underrecognized and therefore underdiagnosed problem that may have significant economic implications. The risk factors for stroke in children are numerous and differ from those in adults. However, with adequate workup, the etiology can be identified in about 75% of cases. Cardiac disorders and hemoglobinopathy are the most common causes of ischemic infarction in children, whereas various congenital anomalies of the blood vessels or defects in coagulation or platelet function often are found in children with parenchymal hemorrhage. Magnetic resonance imaging provides a noninvasive method of investigating childhood stroke, aiding in both better diagnosis and management of this problem.     

Magnetic resonance imaging of pediatric musculoskeletal trauma

Musculoskeletal injury in children is common and can lead to lifelong disability. The unique ability of magnetic resonance imaging (MRI) to visualize the cartilaginous ends of growing bones, bone marrow, and supporting soft-tissue structures makes it ideally suited for evaluation of injury in these patients and the complicating growth disturbance. This article reviews the role of MRI in several common pediatric musculoskeletal injuries and their related growth disturbances. A review of normal musculoskeletal growth and enchondral ossification and the magnetic resonance signal characteristics of the growing skeleton is provided as necessary background. The discussion includes MRI features of physeal fractures and posttraumatic growth arrest, epiphyseal and osteochondral injuries, stress fractures, avulsion injuries, and musculoskeletal soft-tissue injuries.     

Magnetic resonance imaging of pediatric musculoskeletal trauma

MRI is an important tool for evaluating acute and chronic injuries to the musculoskeletal system. It is effective in demonstrating abnormalities in the knee and hips and in detecting bone and ligamentous trauma that is not evident radiographically.     

Magnetic resonance imaging of the pediatric head and neck

Although the bulk of pediatric head and neck lesions are adequately evaluated by computed tomography (CT) alone, magnetic resonance imaging (MRI) provides valuable additional information in those lesions that are difficult to resolve on CT, and it is almost essential for assessment of possible intracranial extension of disease. The ability of MRI to show intrinsic characteristics of mass lesions can help direct therapeutic decisions. It should be utilized early in the imaging evaluation of most vascular lesions, including juvenile nasal angiofibroma and vascular malformations, in suspected neurogenic tumors, and as an adjunct in those cases where CT does not adequately demonstrate the extent or true nature of a lesion.     

Magnetic resonance imaging of pediatric atraumatic musculoskeletal lesions

MRI has become a useful study for evaluating the musculoskeletal system. This article discusses the technique of pediatric musculoskeletal MRI and its practical applications. MRI appearances of various pathologic entities, including infection, neoplasms, marrow disorders, and joint diseases, are also reviewed.     

Magnetic resonance imaging.

Magnetic Resonance Imaging is the latest diagnostic tool to have a significant impact on patient management. Magnetic Resonance Imaging, or MRI, has been available for over six years but has only in the last 18 months become readily available to many more hospitals in Great Britain. MRI scanners have been purchased by large specialist hospitals but the arrival of mobile MRI scanners has made the technology available to smaller hospitals and groups. The impact of MRI for all clinicians and especially surgeons is great and the following text will outline the advantages of MRI and mobile MRI.     

Magnetic resonance imaging of the kidney.

High tissue contrast, multiplanar image capabilities, and tissue characterization render MR into an ideal imaging modality for effective evaluation of a wide range of renal disorders. It provides high details of anatomy and can suggest the composition of lesions. Improvements of MRI technology during the last years have made MRI increasingly attractive for body imaging. Fast imaging sequences and parallel imaging techniques have proved to be useful in minimizing artifacts from respiratory motion and magnetic susceptibility differences providing superior imaging quality. Additionally, the use of renally eliminated paramagnetic contrast agents permits assessment of parenchymal perfusion and visualization of the excretion of the contrast medium providing information on renal function.     

Magnetic resonance imaging of meningiomas.

MRI with gadolinium enhancement is the imaging modality of choice in the diagnosis of meningiomas. Various MRI features are described. MRI signal intensity characteristics in meningiomas contain information that could be correlated with the histopathology of the tumor. Hyperintensity on T2-weighted images indicates soft tumor consistency and microhypervascularity and is more often seen in aggressive, angioblastic, or meningothelial meningiomas. MRI is useful in demonstrating dural sinus involvement. Meningiomas in unusual locations and their mimics are also presented.     

Magnetic resonance imaging of the adrenal glands.

Differentiation of pathologic alterations of the adrenal glands is still a frequent and challenging problem of daily practice in radiology. Two main groups of patients have to be differentiated: those with clinical symptoms, mainly of endocrinopathies, and those in which a mass of the adrenal gland is detected incidentally. In the first group, magnetic resonance imaging (MRI) plays a minor role, although it allows to detect and often even differentiate the cause of the disease. In the second group, MRI has an excellent performance in differentiating between adenomas and non-adenomatous lesions of the adrenal glands.