Radiology最新文献

Background Current CT ancillary features (AFs) have limitations, as several AFs are more evident at MRI. Precontrast low attenuation may serve as a potential AF in the Liver Imaging Reporting and Data System (LI-RADS). Purpose To evaluate the diagnostic value of precontrast low attenuation at CT as an additional AF for diagnosing hepatocellular carcinoma (HCC) and to assess its impact on LI-RADS diagnostic performance. Materials and Methods This retrospective study included adults at risk of HCC who underwent multiphase dynamic liver CT before hepatic resection or liver transplant at a tertiary referral facility between January and December 2022. Two radiologists assessed the presence of major features and AFs for each hepatic observation on the basis of LI-RADs categories, as follows: LR-3, intermediate probability of malignancy; LR-4, probably HCC; and LR-5, definitely HCC. Each lesion was assigned a LI-RADS category twice: first, by using AFs only (LI-RADS category with AFs only) and next, by using AFs with precontrast low attenuation (LI-RADS category with AFs and precontrast low attenuation). Precontrast low attenuation was defined as an attenuation of the target hepatic observation lower than that of the liver parenchyma based on visual assessment. Histopathologic analysis and clinical assessment were used as reference standards. The diagnostic performance of the two LI-RADS strategies was compared using generalized estimating equations. Results A total of 194 patients (mean age, 59 years ± 10 [SD]; 159 men) with 328 hepatic observations were included: 187 (57.0%) HCCs, 26 (7.9%) non-HCC malignancies, and 115 (35.1%) benign lesions. Precontrast low attenuation was associated with HCCs, yielding a diagnostic odds ratio of 9.1 (95% CI: 4.9, 16.6; P < .001). Adding precontrast low attenuation upgraded 20 observations (17 HCCs and three dysplastic nodules) from LR-3 to LR-4, increasing the proportion of HCCs in LR-4 from 64.7% (22 of 34) to 72.2% (39 of 54). Compared with LR with AFs only, LR with AFs and precontrast low attenuation had a higher sensitivity (88.6% [163 of 187] vs 79.9% [146 of 187]; P < .001), with no evidence of a difference in specificity (82.7% [121 of 141] vs 85.0% [124 of 141]; P = .06). Conclusion Applying precontrast low attenuation at CT as an additional AF increased the proportion of HCCs in LR-4 and improved the sensitivity of LI-RADS for diagnosing HCC. © RSNA, 2025 Supplemental material is available for this article.

Background Evidence is limited on how radiologist interpretation, patient age, breast density, and family history influence interval breast cancer (IBC) risk. Purpose To investigate risk factors for IBC in women enrolled in a biennial population-based mammography screening program in Taiwan. Materials and Methods This retrospective study included women who underwent mammography in a population-based breast cancer screening program in Taiwan between January 1, 2004, and December 31, 2018. Standard two-view digital mammograms were interpreted by board-certified radiologists using Breast Imaging Reporting and Data System criteria. Performance measures included recall rate (RR), cancer detection rate (CDR), and positive predictive value (PPV); radiologist audit scores were derived from RR and PPV 1. IBC was defined as cancer diagnosed after a negative screening result and before the next 2-year screening. Multivariable Poison and logistic regression models with random intercepts for radiologist-facility pairs were used to estimate adjusted relative risks and odds ratios with 95% CIs. Results A total of 2 881 405 women (mean age, 56.1 years ± 6.6 [SD]; range, 45-69 years) underwent 6 592 768 mammographic examinations; 10 944 women were diagnosed with IBC. IBC risk per 1000 person-years was higher in women with a family history of breast cancer than in those without (1.41 [95% CI: 1.33, 1.51] vs 0.77 [95% CI: 0.75, 0.80]; P < .001) and in women with extremely dense breasts compared with those in lower breast density categories (1.15 vs 0.88, 0.54, and 0.29; P < .001). Women whose mammograms were interpreted by a radiologist with an audit score of 0-4 had fewer IBCs than those whose mammograms were interpreted by a radiologist with an audit score of 5 or greater (0.78 vs 1.23 per 1000 person-years; P < .001). Women whose mammograms were interpreted by a radiologist with low RR and CDR had the highest proportion of IBCs among all cancers detected (53.87% [95% CI: 49.71, 57.98]; P < .001). Among missed IBCs, asymmetry was the most common false-negative finding (22%). Conclusion High breast density, family history of breast cancer, and suboptimal radiologist performance were independently associated with increased IBC risk. These findings highlight the importance of performance auditing and targeted strategies to enhance early cancer detection in population screening. © RSNA, 2025 Supplemental material is available for this article.

History: A 64-year-old man was brought to the emergency department after being found unresponsive at home, with family reporting progressive confusion following heavy alcohol intake the previous day. On arrival, he was nonverbal and unresponsive to stimuli. Vital signs showed a normal heart rate and blood pressure, with oxygen saturation measured at 80%. Arterial blood gas analysis revealed a pH of 6.86 (reference range, 7.35-7.45), bicarbonate level of 5.4 mmol/L (reference range, 20-28 mmol/L), and anion gap of 28 mmol/L (reference range, 4-12 mmol/L). Lactate level was elevated, at 7.8 mmol/L (reference range, 1-2 mmol/L). Creatinine level was 1.45 mg/dL (128 µmol/L) (reference range, 0.7-1.3 mg/dL [62-115 µmol/L]). Blood glucose level was 282 mg/dL (15.7 mmol/L) (reference range, 70-99 mg/dL [3.9-5.5 mmol/L]), and white blood cell count was 18.8 × 10⁹/L (reference range, 4.5 × 10⁹/L to 11 × 10⁹/L). Liver function test results were within normal limits. Results of initial noncontrast head CT and CT angiography of the head performed at an outside institution were interpreted as normal. Brain MRI was performed without intravenous contrast material approximately 8 hours after initial presentation. Brain MRI included axial diffusion-weighted imaging (Figs 1-3), T2-weighted fluid-attenuated inversion recovery (FLAIR) imaging (Fig 4), and susceptibility-weighted imaging (Fig 5).

Background Despite transarterial chemoembolization (TACE) serving as the first-line treatment for patients with intermediate stage B hepatocellular carcinoma (HCC), complete response rates are generally below 27%. Purpose To compare the efficacy and safety of an anhydrous cisplatin suspension in ethiodized oil-based TACE versus a conventional aqueous cisplatin emulsion in the treatment of participants with HCC. Materials and Methods In this prospective, multicenter, randomized controlled trial conducted from September 2016 to February 2023, participants from three hospitals in Hong Kong were randomized to an experimental or control group in a 1:1 ratio. The experimental group received an anhydrous cisplatin suspension (4 mL of ethiodized oil with 20 mg of cisplatin powder). The control group received a conventional aqueous cisplatin emulsion. TACE was performed within 4 weeks after randomization in two to three treatments, 2 months apart. Response was assessed with CT and digital subtraction angiography during subsequent TACE. Primary end points were complete tumor response and severe adverse events. Secondary end points included progression-free survival and overall survival (OS). Survival outcomes were compared using the log-rank test and hazard ratios with 95% CIs. Results A total of 77 participants were included (median age, 68 years; IQR, 64-75 years; 59 men). At 6 months, the complete tumor response rate was higher in the suspension group (90% [35 of 39 participants]) compared with the emulsion group (47% [18 of 38 participants]; P < .001). Serious adverse events were similar in the suspension group (2.3% [three of 128 procedures]) and emulsion group (5.2% [eight of 153 procedures]; P = .21). Median progression-free survival was higher in the suspension group (21.1 months; 95% CI:14.3, 38.9) compared with the emulsion group (10.4 months; 95% CI: 7.3, 13.4) (hazard ratio, 0.35; P < .001). Median OS was higher in the suspension group (53.3 months; 95% CI: 40.5, not reached) than in the emulsion group (36.0 months; 95% CI: 25.7, 46.6) (hazard ratio, 0.32; P = .004). Conclusion Ethiodized oil-based TACE using an anhydrous cisplatin suspension resulted in better complete tumor response, progression-free survival, and OS rates compared with the conventional aqueous cisplatin emulsion. ClinicalTrials.gov identifier NCT03268499 © RSNA, 2025 Supplemental material is available for this article.

Background The T2-weighted fluid-attenuated inversion recovery (FLAIR) sequence is part of the routine brain MRI protocol. In regions with strong inhomogeneities in the static magnetic (B₀) field and/or the radiofrequency (RF) field, inadequate magnetization inversion results in artifacts that may mimic or obscure pathologic features. Purpose To reduce artifacts on FLAIR images by using an optimized inversion pulse that is robust to inhomogeneities in both the B₀ and RF fields. Materials and Methods In this prospective study, a FLAIR inversion pulse was designed using optimal control. FLAIR and FLAIR with controlled inversion (C-FLAIR) images were acquired at 3 T in a phantom designed to exhibit strong inhomogeneities in B₀ and in 14 participants (mean age, 36.1 years ± 11.5 [SD]; nine male participants) enrolled between October 2024 and August 2025 at a single academic medical center: nine healthy participants, two with relapsing-remitting multiple sclerosis, one with persistent concussion symptoms, and two with asymptomatic white matter hyperintensities. In the phantom, water signal suppression was assessed visually. In human participants, cerebrospinal fluid signal suppression, presence of artifacts, and visibility of multiple sclerosis lesions and white matter hyperintensities were assessed visually by a radiologist. In eight healthy volunteers, mean signal-to-noise ratio (SNR) and mean contrast-to-noise ratio (CNR) were computed for FLAIR and C-FLAIR, with differences between the sequences evaluated using the Student t test. Results C-FLAIR exhibited nearly perfect inversion in the presence of inhomogeneities in the B₀ field, resulting in the removal of artifactual signal. The image contrast of demyelinating multiple sclerosis lesions and white matter hyperintensities was identical for the optimized pulse and the conventional pulse. There was no evidence of a difference in mean SNR (26.5 ± 3.5 for FLAIR vs 26.4 ± 4.7 for C-FLAIR) or mean CNR (18.5 ± 2.1 for FLAIR vs 17.9 ± 2.4 for C-FLAIR) between sequences. C-FLAIR had 13.8% higher specific absorption rate (0.033 vs 0.029 W/kg) and 6.8% higher time-averaged RF (0.78 vs 0.73 µT). Conclusion C-FLAIR with robust RF inversion showed practical elimination of artifacts caused by incomplete inversion. © RSNA, 2025 See also the editorial by Casselman and Bowen in this issue.

Background The potential of photon-counting detector (PCD) CT for rectal cancer (RC) staging remains, to the knowledge of the authors, unexplored. Purpose To determine the optimal virtual monoenergetic images (VMIs) and quantum iterative reconstruction (QIR) strength in PCD CT for RC T staging and to compare the diagnostic performance with that of MRI. Materials and Methods In this prospective study, participants with RC underwent preoperative contrast-enhanced abdominal PCD CT and rectal MRI between September and November 2024. Portal venous phase PCD CT images including VMIs at 40-70 keV in 10-keV increments and polychromatic images (referred to as T3D by the manufacturer) were reconstructed with five QIR levels (off and levels 1-4), and image quality was evaluated. Two junior radiologists and a senior radiologist independently performed T staging evaluations from T3D, optimal PCD CT images, and MRI scans. Diagnostic performance was compared across modalities using DeLong and McNemar tests. Results Seventy-two participants (mean age, 61 years ± 11.8 [SD]; 40 men) were included for image analysis; 51 underwent radical surgery for T staging analysis. VMIs at 40 keV with QIR level 4 (QIR-4) showed the best signal-to-noise ratio (12.1 ± 2.8), contrast-to-noise ratio (6.2 ± 2.6), and maximal Likert scores (median score, 5; IQR, 5-5) for tumor conspicuity, tumor margin clarity, and overall image quality versus other reconstructions (all P < .001). Compared with T3D, optimal PCD CT improved T3-T4 diagnostic performance for the two junior radiologists (area under the receiver operating characteristic curve [AUC], 0.80 vs 0.64 [P = .03] and 0.82 vs 0.64 [P = .002], respectively) but not for the senior radiologist (AUC, 0.86 vs 0.80; P = .13). Optimal PCD CT demonstrated comparable performance to MRI in overall T staging (accuracy, 65%-76% vs 67%-80%) and T3-T4 staging (AUC, 0.80-0.86 vs 0.78-0.88) across all readers (all P > .05). Conclusion In participants with RC, portal venous abdominal PCD CT at 40 keV and with QIR-4 yielded the optimal image quality for RC T staging, showed enhanced T3-T4 diagnostic performance among less-experienced radiologists, and achieved performance that was comparable to that of MRI. © RSNA, 2025 Supplemental material is available for this article.