American Journal of Roentgenology最新文献

BACKGROUND. Applicator insertion parallel to the bronchovascular bundle has been recommended for percutaneous ablation of central lung tumors. However, the relationship between the applicator insertion angle and adverse events remains understudied. OBJECTIVE. The purpose of this study was to examine associations of the pleural puncture angle and other factors with major adverse events after percutaneous ablation of lung tumors. METHODS. This retrospective study included consecutive patients who underwent percutaneous cryoablation or microwave ablation (MWA) of lung tumors at two academic medical centers between February 1, 2008, and April 30, 2023. A reader measured the pleural puncture angle on intraprocedural CT images. A second reader independently performed measurements in a subset to assess interreader agreement. Sessions were classified as central if at least one targeted tumor was located more than 4 cm from the costal pleura and as noncentral otherwise. The relationship between major adverse events and the pleural puncture angle was evaluated by separate multivariable logistic regression models for central and noncentral sessions; models also included modality (cryoablation vs MWA), number of pleural punctures (< 3 vs ≥ 3), applicator path through lung parenchyma, and maximum applicator gauge. RESULTS. The analysis included 260 patients (152 women, 108 men; median age, 65 years) who underwent 416 sessions (299 cryoablation procedures, 117 MWA procedures; median pleural puncture angle, 57°) targeting 638 tumors. Interreader agreement for pleural puncture angle in 100 randomly selected cases was excellent (intraclass correlation coefficient = 0.94). A total of 86 (21%) sessions were classified as central and 330 (79%) as non - central. Major adverse events occurred after 37 (9%) sessions. In multivariable analyses, for central sessions, major adverse events were independently associated only with pleural puncture angle (OR per 1° = 0.94; p = .01); in noncentral sessions, major adverse events were independently associated with MWA (OR = 2.98; p = .03) and three or more pleural punctures (OR = 3.75; p = .004), but not with other factors including pleural puncture angle. CONCLUSION. For ablations targeting central tumors, steeper pleural puncture angles were associated with fewer major adverse events. For ablations targeting noncentral tumors, the use of MWA and three or more pleural punctures were associated with increased major adverse events. CLINICAL IMPACT. The findings support applicator insertion with a steep pleural puncture angle during percutaneous ablation of central lung tumors.

Despite growing clinical use of contrast-enhanced ultrasound (CEUS), inconsistency remains in the modality's role in clinical pathways for hepatocellular carcinoma (HCC) diagnosis and management. This AJR Expert Panel Narrative Review provides practical insights on the use of CEUS for the diagnosis of HCC across populations, including individuals at high risk for HCC, individuals with metabolic dysfunction-associated steatotic liver disease, and individuals not at high risk for HCC. Considerations addressed with respect to high-risk patients include CEUS diagnostic criteria for HCC, use of CEUS for differentiating HCC from non-HCC malignancy, use of CEUS for small (≤ 2 cm) lesions, use of CEUS for characterizing occult lesions on B-mode ultrasound, and use of CEUS for indeterminate lesions on CT or MRI. Representative literature addressing the use of CEUS for HCC diagnosis and gaps in knowledge requiring further investigation are highlighted. Throughout these discussions, the article distinguishes two broad types of ultrasound contrast agents used for liver imaging: pure blood-pool agents and a combined blood-pool and Kupffer-cell agent. Additional topics include the use of CEUS for treatment response assessment after nonradiation therapies and implications of artificial intelligence technologies. The article concludes with a series of consensus statements from the author panel.

Concerns about the risk of radiation from CT have driven a spectrum of major advances in radiation dose reduction technology since the 2000s, including added beam filtration, dynamic z-axis collimation, automatic tube current modulation and tube potential selection, advanced iterative reconstruction, and deep learning-based reconstructions. The introduction of photon-counting detector CT further improved dose efficiency through electronic noise rejection, optimal photon-energy weighting, and high-resolution data acquisition. This Review summarizes key milestones and technologic innovations that have led to substantial reductions in CT radiation doses and provides examples of the cumulative impact of these advances on CT doses and image quality for routine examinations in various anatomic sites. This article also highlights the importance of an objective task-based image quality assessment to ensure that diagnostic performance is not compromised as dose is reduced, particularly for emerging deep-learning-based reconstruction and postprocessing noise reduction methods.