Seminars in Ultrasound Ct and Mri最新文献

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.

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.

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]).

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.

Primary central nervous system lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin's lymphoma that accounts for 1%-5% of all central nervous system tumors. Contrast-enhanced MR is the imaging technique of choice. PCNLs have a predilection for the periventricular and superficial regions, often abutting the ventricular or meningeal surfaces. Although PCNLs may have characteristic imaging features on conventional MRI, none of these will unequivocally differentiate PCNSLs from other brain lesions. Diffusion restriction, relative hypoperfusion, increased choline/creatinine, decrease of N-acetyl aspartate (NAA) peak as well as the presence of lactate and lipid peaks are consistent advanced imaging findings in CNS lymphoma that may help in the differentiation of Primary central nervous system lymphomas (PCNSLs) from other malignancies. Furthermore, advanced imaging techniques will presumably play an important role in the planning of new targeted therapies, for prognostication, and for the monitoring of treatment response in the future.

Neuroimaging plays a key role in the diagnosis and differentiation of brain metastases (BM) in patients with known or unknown malignancies. Computed tomography and magnetic resonance imaging are the key imaging modalities used in the detection of BM. Advanced imaging techniques including proton magnetic resonance spectroscopy, magnetic resonance perfusion, diffusion weighted imaging, and diffusion tensor imaging may aid in arriving at the correct diagnosis, in particular cases, such as newly diagnosed solitary enhancing brain lesions in patients without known malignancy. Imaging is also performed to predict and/or assess the efficacy of treatment, and to differentiate residual or recurrent tumors from therapy-related complications. Furthermore, the recent advent of artificial intelligence is opening up a vast scenario for the analysis of quantitative information deriving from neuroimaging. In this image-rich review, we provide an up-to-date overview on the application of imaging in patients with BM. We describe typical and atypical imaging findings of parenchymal and extra-axial BM on Computed tomography, magnetic resonance imaging, and positron emission tomography, focusing on the role of advanced imaging techniques, that can serve as problem-solving tools in the management of patients with BM.

Dual-energy CT (DECT) imaging makes it possible to identify the characteristics of materials that cannot be recognized with conventional single-energy CT (SECT). In the postprocessing study phase, virtual monochromatic images and virtual-non-contrast (VNC) images, also permits reduction of dose exposure by eliminating the precontrast acquisition scan. Moreover, in virtual monochromatic images, the iodine contrast increases when the energy level decreases resulting in better visualization of hypervascular lesions and in a better tissue contrast between hypovascular lesions and the surrounding parenchyma; thus, allowing for reduction of required iodinate contrast material, especially important in patients with renal impairment. All these advantages are particularly important in oncology, providing the possibility of overcoming many SECT imaging limits and making CT examinations safer and more feasible in critical patients. This review explores the basis of DECT imaging and its utility in routine oncologic clinical practice, with particular attention to the benefits of this technique for both the patients and the radiologists.

Hepatocellular carcinoma (HCC) is the most common liver cancer and is one of the uppermost 2 causes of cancer death. About 70%-90% of HCCs develop within a cirrhotic liver. According to the most recent guidelines, the imaging characteristics of HCC on contrast-enhanced Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) are generally satisfactory to make a diagnosis. Recently, new advanced techniques such as contrast-enhanced ultrasound, CT perfusion, Dynamic Contrast-enhanced MRI, diffusion weighted imaging and radiomics have increased the diagnostic accuracy and characterization of HCC. This review illustrates the state of the art and recent advances in non-invasive imaging evaluation of HCC.

Gastrointestinal stromal tumors (GISTs) arise from the interstitial cells of Cajal in the gastrointestinal tract and are the most common intestinal tumors. Usually GISTs are asymptomatic, especially small tumors that may not cause any symptoms and may be found accidentally on abdominal CT scans. Discovering of inhibitor of receptor tyrosine kinases has changed the outcome of patients with high-risk GISTs. This paper will focus on the role of imaging in diagnosis, characterization and follow-up. We shall also report our local experience in radiomics evaluation of GISTs.