Radiographics最新文献

Contrast-enhanced mammography (CEM) is a functional imaging study performed by using intravenously administered iodinated contrast material and digital mammography equipment to acquire low- and high-energy images directly after each other and during the same breast compression. The images are processed using a weighted subtraction to obtain the contrast-enhanced image-also called the recombined image-on which areas of enhancement are visualized. Much like MRI, CEM with intravenous contrast material provides enhancement that improves diagnostic accuracy compared with that achieved with standard mammography and has sensitivity and specificity for cancer detection similar to those of MRI. The use of CEM has increased in part due to its accessibility and ease of use, making it essential that radiologists become familiar with interpreting and reporting CEM findings. Becoming educated on this examination is essential, and adoption of the associated lexicon is critical to facilitating standardized reporting and effective communication between radiologists and clinicians. Learning to read CEM images can be straightforward, especially when radiologists apply their knowledge of and experience with full-field digital mammography and MRI to CEM. Using the American College of Radiology CEM supplement and the fifth edition of the Breast Imaging Reporting and Data System (BI-RADS) manual, the authors systematically review the similarities and differences between the CEM lexicon and the existing mammography and MRI lexicons, providing a framework for radiologists who interpret and report on CEM cases. In addition, they discuss the potential limitations of CEM and the role of this examination in common and challenging diagnostic scenarios. ^©RSNA, 2025.

Mechanical circulatory support devices (MCSDs) have revolutionized the management of advanced heart failure and critical cardiopulmonary conditions. These devices, categorized into temporary and long-term systems, provide crucial circulatory and respiratory support in patients with cardiogenic shock, refractory heart failure, and/or acute respiratory distress syndrome or act as a bridge to recovery or transplant. Temporary devices such as intra-aortic balloon pumps, percutaneous heart pumps, percutaneous ventricular assist devices (VADs), and dual-lumen cannulas are essential for acute hemodynamic stabilization. Long-term devices, including VADs and total artificial hearts (TAHs), offer durable solutions and may be used as a destination therapy or a bridge to heart transplant. Extracorporeal membrane oxygenation, also referred to as extracorporeal life support, provides cardiopulmonary support for patients with severe respiratory failure with or without cardiac failure. Despite their transformative role, MCSDs are associated with significant risks, including mechanical and medical complications. Imaging modalities such as echocardiography and CT are integral to optimal management of MCSDs and aid in device placement, functionality assessment, and early identification of complications, ensuring patient safety and improved outcomes. Recent advancements in device technology, including third-generation continuous-flow VADs and TAH systems, have led to improved survival and reduced complication rates. However, recent recalls and regulatory updates underscore the need for ongoing vigilance in device selection, implantation, and monitoring. The authors highlight the types of and indications for using MCSDs, their normal imaging appearances, and findings associated with common complications. The latest updates in MCSD technology are discussed, and the pivotal role of imaging in optimizing the management of patients with MCSDs is emphasized. ^©RSNA, 2025.

Acute mesenteric ischemia (AMI) is an abdominal emergency characterized by a sudden decrease in blood flow to meet the metabolic demands of bowel. AMI is uncommon but associated with high morbidity and mortality. Imaging plays a decisive role in early diagnosis and management because the symptoms of AMI are often nonspecific without specific laboratory tests or serologic biomarkers for early diagnosis. AMI comprises distinct entities with unique pathophysiology, imaging features, and management strategies. The basic causal mechanisms underlying AMI are inadequate inflow (arterial occlusion), inadequate outflow (mesenteric venous occlusion), global hypoperfusion (nonobstructive mesenteric ischemia [NOMI]), and strangulating bowel obstruction. Identifying transmural necrosis is critical for all causes of AMI. The authors review the foundational anatomy and pathophysiology of AMI, its distinct imaging features, and a systematic approach to AMI with emphasis on up-to-date imaging findings predictive of transmural necrosis. They emphasize a pathophysiology-based approach to AMI rather than a semiology-based approach (ie, patterns and signs) because the imaging features, significance, and predictive value of the imaging findings vary based on the underlying cause of AMI, with arterial occlusive AMI and NOMI having worse prognosis than mesenteric venous AMI. The authors highlight the specific vascular, bowel, and extraintestinal findings for each type of AMI with emphasis on imaging predictors of transmural bowel necrosis and address points of confusion to equip interpreting radiologists with a foundational understanding of AMI. ^©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Huete in this issue.

Urethral diseases in males, such as strictures, traumarelated injuries, and neoplasms, are significant clinical challenges that can greatly impact urinary function and quality of life. The complex anatomy of the male urethra, which traverses structures such as the prostate and corpus spongiosum, make it particularly susceptible to injuries and strictures compared with the female urethra. The clinical assessment of urethral abnormalities is often limited, necessitating the use of imaging studies for thorough evaluation. While traditional radiographic techniques such as retrograde urethrography and voiding cystourethrography enable visualization of the urethral lumen, they have limitations in the assessment of periurethral tissues. MR urethrography (MRU) has emerged as a noninvasive modality that offers detailed anatomic insights into the urethra and periurethral structures. The authors review the embryologic features and anatomy of the male urethra and the risk factors associated with male urethral diseases. In addition, helpful imaging methods are discussed, with specific emphasis on MRI as a comprehensive modality and on optimal techniques for MRU protocols. A range of urethral diseases are described and illustrated, and key points for reporting MRU findings are highlighted. ^©RSNA, 2025 Supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Bowel sonography comprises the study of inflammatory bowel disease (IBD) and other inflammatory and neoplastic bowel conditions associated with gross morphologic change. For the most common application, IBD, it is well established that gray-scale US and color Doppler US imaging (CDI) allow excellent assessment of the status of the bowel wall, blood flow to the bowel and mesentery, and the presence or absence of perienteric inflammatory fat. Although these techniques provide effective and accurate methods to assess the bowel, they are not always comprehensive. Bowel loops residing in the true pelvis may not be accessible from a transabdominal approach, and CDI is not sensitive at increased depths and in patients with obesity. Most important, CDI only shows fast-moving flow in large blood vessels, with a limited ability to show blood flow at the microvascular level. Bowel stiffness is also not included in a standard gray-scale assessment. Three readily available ancillary US techniques can be used to overcome these imaging challenges and to greatly improve detection of pathologic conditions and patient outcomes. These techniques are endovaginal US to visualize pathologic conditions in the deep pelvis, contrast-enhanced US to subjectively and objectively assess blood flow to the capillary level, and two-dimensional shear-wave elastography to determine bowel stiffness as a measure of disease chronicity. The authors provide a detailed description of the application of these techniques with case examples demonstrating the added benefit. ^©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Barr in this issue.

Postoperative fluid collections are commonly encountered at imaging after lumbar spine surgery. While small collections usually resolve on their own, larger or more complex ones have a limited differential diagnosis. Varied surgical approaches to the lumbar spine may predispose patients to different types of fluid collections, including seromas, hematomas, pseudomeningoceles, abscesses, bone morphogenetic protein (BMP)-related collections, lymphoceles, and urinomas; thus, radiologists should be aware of the different types of anterior and posterior surgical approaches to lumbar spine interbody fusion. Hematomas and abscesses may occur with any surgical approach. Pseudomeningoceles most frequently result after posterior approach surgery, while urinomas and lymphoceles more likely develop after anterior approach surgery due to the close proximity of the surgical corridor to the nephroureteral system or lymphatics, respectively. Surgical implants or biologics used at surgery can lead to BMP-related collections; awareness of any implanted materials intraoperatively can be helpful at the time of interpretation. While MRI is most frequently used for identifying fluid collections in the postoperative spine, CT can serve as an important adjunct. CT myelography can be used to confirm or exclude the presence of a pseudomeningocele but may not be necessary if MRI shows a confirmatory flow jet, confirming leakage of cerebrospinal fluid into the pseudomeningocele. CT enhanced with intravenous contrast material during the excretory phase also allows confirmation of the presence of a urinoma. When the contents of a postoperative fluid collection remain uncertain, aspiration may be necessary. Accurate diagnosis of the type of postoperative collection is extremely useful in guiding patient management and determining prognosis. ^©RSNA, 2025.