Seminars in Ultrasound Ct and Mri最新文献

Common hip internal derangements include femoroacetabular impingement (FAI), developmental dysplasia of hip (DDH) dysplasia, and avascular necrosis (AVN) of the femoral head. These are initially screened by radiographs. For preoperative planning of hip preservation, 3-dimensional (3D) CT is commonly performed to assess bony anatomy and its alterations. Magnetic resonance imaging (MRI) is used to evaluate labrum, hyaline cartilage, tendons, synovium, and loose bodies, and provides vital information for surgical decision-making. However, conventional 2D MRI techniques are limited by lack of isotropic multiplanar reconstructions and partial volume artifacts. With advancements in hardware and software, novel isotropic 3D MR Proton Density images are acquired with acceptable acquisition times leading to improved visualization of soft tissue and osseous structures for various hip conditions. Three-Dimensional MRI allows multiplanar non-gap reconstructions along the structures of interest. It results in detection of small, otherwise inconspicuous labral tears without the need for MR arthrogram, which can be subsequently measured. In addition, radial reconstructions of the femoral head can be performed from original 3D volume MR imaging and CT imaging without the need for individual different plane acquisitions. Three-Dimensional MRI thus impacts surgical decision-making for the important common hip derangement conditions. For example, femoral head hyaline cartilage loss may make hip preservation difficult or impossible. In this review, we discuss the advantages and technical details of 3D CT and MRI and their significant role in aiding hip preservation surgery for common hip conditions. The conditions discussed in this article include FAI, DDH, AVN, synovial disorders, cartilaginous tumors, and hip fractures.

A comprehensive understanding of the anatomy and biomechanics of muscle fibers and tendons is crucial to comprehend their functions. The orientation of tendon fibers plays a significant role in the pathologies that affect them and the resulting functional impairments. In this review, we provide detailed information on the origin, insertion, and fiber orientation of selected muscles and tendons, as well as their functional significance. To aid in comprehension, we have included illustrations depicting the anatomy and fiber orientation, as well as cross-sectional MR images that highlight important imaging features of normal anatomy and tears of select lower extremity tendons.

Being a major load-bearing and dynamic functional joint of the body, the knee joint is prone to injuries to the menisci and ligaments. Injury to one or more of these structures leads to accelerated or premature osteoarthritis and chronic debilitation. The estimated cost of these injuries in terms of diagnosis, treatment, rehabilitation, and person-hours lost amounts to over a billion dollars annually. Understanding the relevant anatomy of knee cruciate and collateral ligaments, their biomechanical functional role, and imaging considerations are essential to assist multi-disciplinary communications and timely patient treatments for improved management. MRI is considered the gold standard over other imaging modalities like X-ray, ultrasound (US), and Computed Tomography (CT) for diagnosing and assessing such injuries. High-resolution 2D and 3D MRI are considerably helpful in planning for knee preservation surgery, and this article reviews the role of such imaging as a valuable aid to knee preservation surgery in pre-and post-operative states. Relevant arthroscopy correlations have been illustrated.

Total hip arthroplasty is an effective treatment for severe degenerative arthritis and is increasingly being used. Radiography is the primary modality for the initial diagnosis of osteoarthritis and preoperative planning. Additional radiographic views may include the spine and lower extremities in order to optimize implant positioning for the individual patient. Computed tomography is sometimes used for preoperative planning and intraoperative robotic assistance. Magnetic resonance imaging and diagnostic ultrasound is generally reserved for patients without obvious arthritis. Ultrasound-guided injections may provide diagnostic and/or therapeutic benefits.

Peripheral nerve injury is a common sequela of lower extremity trauma. Injuries to lower extremity nerves range from contusions and stretch injuries that will often resolve without interventions to traumatic disruptions requiring surgical procedures, including neurolysis, repair or even nerve grafting. While clinical examination and tools such as electromyography will often help to localize the site of injury, imaging is a critical tool in determining the extent and degree of nerve injury in the setting of trauma. Modalities such as ultrasound and radiography are often useful, but MRI is considered the primary imaging modality for assessing the extent and degree of nerve injury. Specialized techniques such as MR neurography tailored to the needs of individual patients can provide important and detailed information in support of clinical decision making and presurgical planning. In this paper, we will review the anatomy of peripheral nerves of the lower extremity, mechanisms of injury affecting nerves and provide guidance for the use of MRI correlated with validated classification systems in assessing injuries affecting the nerves of the lower extremities.

Injuries to the plantar plate complex of the first toe and the lesser toes, although closely related anatomically, differ significantly in their pathogenesis. Lesser metatarsophalangeal joint plantar plate degeneration and tear typically presents as an attritional pattern of capsuloligamentous deficiency in middle-aged patients, whereas first metatarsophalangeal joint capsuloligamentous injury is typically acute and occurs in younger adult athletes engaged in sports involving repetitive running and jumping. Consequently, considerations regarding surgical decision-making also differ. Knowledge of the anatomy, pathophysiological basis, common patterns, grading and classification of these injuries, and indications for surgery, will aid imaging interpretation in the preoperative setting. The acuity and extent of injury, tissue quality and functional requirements of the patient (such as timely return to sport) influence clinical decision-making with respect to conservative versus surgical management and are informed by the use of optimized multimodal imaging. This section will provide an overview of these injuries in 2 parts, separated into those affecting the first toe and the lesser toes, and will highlight imaging findings relevant to surgical decision-making.

Ankle tendon pathology is an important cause of pain, instability, and disability. Surgical treatment is often employed when conservative management fails. The quantity and variety of ankle tendon repair/reconstruction surgeries have increased over time. As surgical techniques for ankle tendon surgery evolve and increase in prevalence, postoperative imaging of these tendons rises. Therefore, it is exceedingly important for radiologists to be familiar with these procedures, their expected postoperative appearance, imaging pitfalls, and potential complications. This article reviews the key imaging findings of a variety of common ankle tendon surgical procedures.

Cervical cancer is the fourth most common cancer in women, and it is divided into 2 main histological types: squamous cell carcinoma and adenocarcinoma. Extension of disease as well as the presence of metastases define the prognosis of patients. Accurate tumor staging at diagnosis is essential for adequate planning for treatment. There are several classifications of cervical cancer, and the most used are FIGO and TNM, which help classify the patient and guide the treatment. Imaging has a pivotal role in classifying patients, and MRI plays a decision-maker role both for diagnosis and for treatment planning. In this paper we highlight the role of MRI, alongside guidelines classification, in patients with different stages of cervical tumors.

The assessment of tumor response, after neoadjuvant radiochemotherapy (n-CRT), permits the stratification of patients for the proper therapeutical management. Although histopathology analysis of the surgical speciemen is considered the gold standard for assessing tumor response, magnetic resonance imaging (MRI), with its significant developments in technical imaging, have allowed an increase in accuracy for the evaluation of response. MRI provides a radiological tumor regression grade (mrTRG) that is correlated with the pathologic tumor regression grade (pTRG). Functional MRI parameters have additional impending in early prediction of the efficacy of therapy. Some of functional methodologies are already part of clinical practice: diffusion-weighted MRI (DW-MRI) and perfusion imaging (dynamic contrast enhanced MRI [DCE-MRI]).