Radiographics最新文献

First-trimester US is imperative in evaluation of early pregnancy to confirm pregnancy location and number and gestational age. The 2024 Society of Radiologists in Ultrasound consensus conference established a first-trimester lexicon to highlight the importance of clear and concise language, which is incorporated and featured by the authors. With improved technologies and understanding of fetal development, first-trimester anatomic studies, between 11 weeks and 13 weeks 6 days gestation, are becoming more frequently used. While not a replacement for the second-trimester anatomic study, systematic evaluation of fetal anatomy at this early gestational age allows detection of 40%-70% of anomalies, whether structural or related to aneuploidy. All patients, regardless of age or baseline risk, should be offered screening and diagnostic testing for chromosomal abnormalities. A variety of prenatal screening approaches are available, each with strengths and limitations. Noninvasive prenatal testing with detection of fetal cell-free DNA can be performed in the first trimester and is the most sensitive and specific screening for the common fetal aneuploidies, but is not equivalent to diagnostic testing. Alternatively, serum analytes for maternal biomarkers in conjunction with nuchal translucency (NT) measurement can be used to calculate a risk estimate for common trisomies. Increased NT is the most common abnormality seen in the first trimester. Positive screening results, increased NT, or other anomaly at US should prompt genetic counseling and be confirmed with diagnostic testing (chorionic villus sampling or amniocentesis). Early detection of aneuploidy and structural anomalies allows counseling and informs decisions for pregnancy management. ^©RSNA, 2025 Supplemental material is available for this article.

Parathyroid imaging in hyperparathyroidism management is not solely to support the diagnosis but also to precisely localize abnormal parathyroid tissue, thus enabling minimally invasive parathyroidectomy. US offers a noninvasive and cost-effective method for identifying and characterizing parathyroid lesions. Common causes include solitary parathyroid adenoma, multiple adenomas, and parathyroid hyperplasia. Despite its advantages, US has limitations, including difficulty in demonstrating deep-seated or ectopic glands. Radiologists must exercise caution in distinguishing parathyroid lesions from mimics such as thyroid nodules and lymph nodes using various imaging modalities including high-resolution neck US, scintigraphy, four-dimensional CT, and MRI. The authors focus on the role of US in evaluating parathyroid pathologic conditions, highlighting its advantages in concurrent detection of thyroid nodules while also discussing the complementary role and benefits of alternative imaging modalities. Common mimics encountered during imaging evaluation are briefly outlined. ^©RSNA, 2025 Supplemental material is available for this article.

The lumbosacral plexus (LSP) comprises a complex network of nerves supplying the pelvis and lower extremities and may be affected by a wide range of diseases. Lumbosacral plexopathy can be challenging to diagnose due to overlapping clinical presentations and difficulty performing electrodiagnostic testing of the deep pelvic structures. MRI-more specifically, MR neurography (MRN)-can readily depict most LSP segments. MRN techniques, preferably performed at 3.0 T, continue to evolve, with most protocols including two-dimensional and optionally three-dimensional, heavily T2-weighted fat-suppressed sequences. This article provides technical tips for optimizing LSP MRN, as well as an overview of various LSP-related pathologic conditions, with accompanying illustrative examples. ^©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Chhabra in this issue.

Lymphoma, a diverse group of neoplasms, has been frequently refined in classification, with over 100 types identified by the World Health Organization in 2022. Lymphoma represents 5% of new malignancies in the United States, the risk factors of which include genetic predisposition, infections, and inflammatory conditions. Extranodal lymphoma, constituting 25%-40% of cases, uncommonly involves the musculoskeletal system, with diffuse large B-cell lymphoma being the primary type. Bone lymphoma, classified as primary, primary multifocal, or secondary, predominantly affects the appendicular skeleton. Radiography and CT aid osseous evaluation and may reveal a lytic, sclerotic, mixed lytic and sclerotic, or near-normal appearance. MRI excels in soft-tissue and bone marrow assessment, and PET/CT plays a pivotal role in staging. Soft-tissue lymphoma, which involves various compartments, is best characterized with MRI, whereas US may be the modality first used for evaluation. Staging involves fluorodeoxyglucose (FDG) PET/CT, and treatment response is assessed through various imaging modalities. Skin involvement, commonly associated with primary cutaneous T-cell lymphoma, is described through stages, with FDG PET aiding diagnosis. Transspatial lymphoma involves multiple contiguous spaces and is known in the head and neck but not well documented in the musculoskeletal system. The authors provide comprehensive insight into musculoskeletal lymphoma by highlighting imaging findings crucial for diagnosis, classification, staging, and assessment of treatment response. ^©RSNA, 2025.

Pseudomyxoma peritonei involves the gradual accumulation of gelatinous peritoneal metastases, typically resulting from the rupture of a mucinous appendiceal neoplasm. Standard treatment often includes cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. However, recurrence is common despite optimal cytoreduction, prompting ongoing investigation into novel therapies. This comprehensive review aims to enhance radiologists' understanding of mucinous appendiceal neoplasms and pseudomyxoma peritonei by focusing on nomenclature, pathophysiology, optimal imaging strategies, and the typical imaging appearance of mucinous appendiceal neoplasm and associated peritoneal disease. It also highlights problematic areas of disease that may affect the ability to achieve complete cytoreduction or influence surgical decision making and includes a surgeon's perspective on treating this complex condition.

Pediatric renovascular hypertension (RVHTN) results from flow-limiting disease of the renal arterial vasculature and is a potentially treatable cause of pediatric hypertension. Causes of pediatric RVHTN include idiopathic causes, fibromuscular dysplasia, neurofibromatosis, vasculitis, traumatic vascular injury, aneurysms, and aberrant renal arterial supply. Diagnostic imaging allows screening for and confirmation of pediatric RVHTN. Renal sonography with Doppler evaluation is the initial test of choice, followed by CT angiography and MR angiography. However, these modalities may not demonstrate intrarenal segmental or subsegmental branch disease. Therefore, conventional angiography maintains a significant role in diagnosis of pediatric RVHTN. Once diagnosed, pediatric RVHTN is initially treated with antihypertensive medications. Minimally invasive procedures, including angioplasty and embolization, may temporize or cure RVHTN. Surgical intervention-including renal artery reconstruction or reimplantation, aortorenal bypass grafting, or even nephrectomy-may be required for flow-limiting pathologic conditions, which often require endovascular strategies for maintenance. Renal artery stent placement is generally avoided due to limited data and risk of occlusion, although it can be considered in cases of iatrogenic dissection or severe elastic recoil refractory to angioplasty. Having appropriately sized covered stent-grafts nearby as a safety precaution is encouraged when performing these interventions. Radiologists play an invaluable role in the care of patients with pediatric RVHTN through multimodality diagnostic tools, both noninvasive and minimally invasive. The authors review medical management, diagnostic imaging, and endovascular interventions involved in caring for patients with pediatric RVHTN, to optimize diagnostic and interventional radiologist participation in multidisciplinary care with pediatric nephrologists and vascular surgeons. ^©RSNA, 2025 Supplemental material is available for this article.

Image-guided percutaneous lung ablation has become increasingly common in the treatment of non-small cell lung cancer (NSCLC) and oligometastatic disease in recent years. Among the available techniques are well-described heat-based techniques, such as lung radiofrequency or microwave ablation, and lung cryoablation (LCA), based on the use of extreme cold to cause tissue necrosis. Although it is the least used of the three ablative techniques available for lung ablation, LCA has inherent characteristics that render it the preferred technique in certain situations. Due to the nature of cryoablation, the collagen extracellular matrix of the tissue adjacent to the ablation site is preserved during the intervention. Additionally, cryoablation may allow more precise imaging monitoring of the ablation zone compared with heat-based techniques. These intrinsic advantages potentially establish LCA as the preferred ablative technique for treating lung tumors located near sensitive vital structures, such as the heart, pulmonary hilum, pulmonary arteries, aorta, main bronchi, and pleura. The authors discuss the basic principles of LCA; the indications and contraindications of the technique; and the technical details of the treatment, including the expected findings and periprocedural complications. A standardized scheme for post-cryoablation imaging follow-up is proposed, detailing the expected findings of complete response and signs of tumor persistence and recurrence and specifying the differences seen with heat-based ablative techniques. ^©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Parvinian and Eiken in this issue.