A CT-based radiomics signature, based on histogram, shape, and local-regional texture features, showed an association with immune response in advanced solid tumors. Background Reliable predictive imaging markers of response to immune checkpoint inhibitors are needed. Purpose To develop and validate a pretreatment CT-based radiomics signature to predict respons...

"Just Accepted" papers have undergone full peer review and have been accepted for publication in Radiology: Artificial Intelligence. This article will undergo copyediting, layout, and proof review before it is published in its final version. Please note that during production of the final copyedited article, errors may be discovered which could affect the content. Purpose To identify precise 3D radiomics features in CT images that enable computation of stable and biologically meaningful habitats with machine learning for cancer heterogeneity assessment. Materials and Methods This retrospective study included 2436 liver or lung lesions from 605 CT scans (November 2010-December 2021) in 318 patients with cancer (mean age, 64.5 years ± 10.1 [SD]; 185 male patients). 3D radiomics were computed from original and perturbed (simulated retest) images with different combinations of feature computation kernel radius (R) and bin size (B). The lower 95% confidence limit (LCL) of the intraclass correlation coefficient was used to measure repeatability and reproducibility. Precise features were identified by combining repeatability and reproducibility results (LCL ≥ 0.50). Habitats were obtained with Gaussian Mixture Models in original and perturbed data using precise radiomics features and compared with habitats obtained using all features. The Dice similarity coefficient (DSC) was used to assess habitat stability. Biologic correlates of CT habitats were explored in a case study, with a cohort of 13 patients with CT, multiparametric MRI (mpMRI) and tumor biopsies. Results 3D radiomics showed poor repeatability (median LCL[IQR] of 0.442 [0.312-0.516]) and poor reproducibility against R (0.44[0.33-0.526]) but excellent reproducibility against B (0.929[0.853-0.988]). Twentysix radiomics features were precise, differing in lung and liver lesions. Habitats obtained with precise features (DSC, 0.601 (0.494-0.712) and 0.651 (0.52-0.784) for lung and liver lesions, respectively) were more stable than those obtained with all features (DSC, 0.532 (0.424-0.637) and 0.587 (0.465-0.703), respectively; P < .001). In the case study, CT habitats correlated quantitatively and qualitatively, with heterogeneity observed in mpMRI habitats and histology. Conclusion Precise 3D radiomics features were identified on CT that enabled tumor heterogeneity assessment through stable tumor habitat computation. ©RSNA, 2024.

A new and externally validated MRI-PM for csPCa was developed in the metropolitan area of Barcelona, and a web-RC designed with the new option of selecting the csPCa probability threshold. The development cohort comprised 1486 men scheduled to undergo a 3-tesla multiparametric MRI (mpMRI) and guided and/or systematic biopsies in one academic institution of Barcelona. The external validation cohort comprised 946 men in whom the same diagnostic approach was carried out as in the development cohort, in two other academic institutions of the same metropolitan area. CsPCa was detected in 36.9% of men in the development cohort and 40.8% in the external validation cohort (p = 0.054). The area under the curve of mpMRI increased from 0.842 to 0.897 in the developed MRI-PM (p < 0.001), and from 0.743 to 0.858 in the external validation cohort (p < 0.001). A selected 15% threshold avoided 40.1% of prostate biopsies and missed 5.4% of the 36.9% csPCa detected in the development cohort. In men with PI-RADS <3, 4.3% would be biopsied and 32.3% of all existing 4.2% of csPCa would be detected. In men with PI-RADS 3, 62% of prostate biopsies would be avoided and 28% of all existing 12.4% of csPCa would be undetected. In men with PI-RADS 4, 4% of prostate biopsies would be avoided and 0.6% of all existing 43.1% of csPCa would be undetected. In men with PI-RADS 5, 0.6% of prostate biopsies would be avoided and none of the existing 42.0% of csPCa would be undetected. The Barcelona MRI-PM presented good performance on the overall population; however, its clinical usefulness varied regarding the PI-RADS category. The selection of csPCa probability thresholds in the designed RC may facilitate external validation and outperformance of MRI-PMs in specific PI-RADS categories.

A difference of greater than 1.2 cm2 between areas of the proximal and distal entry tears at CT angiography in the subacute phase of aortic dissection was related to adverse events. Purpose To identify entry tear variables that are related to adverse clinical events by using CT angiography (CTA) performed during the subacute phase of aortic dissection. Materials and Methods In...

Histotripsy is a novel noninvasive nonthermal, nonionizing, and precise treatment technique for tissue destruction. Contrast-enhanced ultrasound (CEUS) improves the detection, characterization, and follow-up of hepatic lesions because it depicts accurately the vascular perfusion of both normal hepatic tissue and hepatic tumors. We present the spectrum of imaging findings of CEUS after histotripsy treatment of hepatic tumors. CEUS provides real-time information, a close approximation to the dimension of the lesion, and a clear definition of its margins. Hepatic tumors detected by ultrasound can be potentially treated using B-mode ultrasound-guided histotripsy and characterized and monitored with CEUS. CEUS has shown to be very useful after tissue treatment to monitor and assess the evolution of the treated zone. Histotripsy treated zones are practically isoechogenic and slightly heterogeneous, and their limits are difficult to establish using standard B-mode ultrasound. The use of CEUS after histotripsy showing uptake of contrast protruding into the treated zone is clinically relevant to identify residual tumors and establish the most appropriate management strategy avoiding unnecessary treatments. We here describe CEUS findings after histotripsy for hepatic tumors.

Background: Tele-robotic ultrasound (US) is a novel technique that might help overcome the current shortage of radiologists and poor access to radiologists and/or sonographers in remote or rural areas. Despite the promising results of this technology in the past two decades, there is still insufficient data about its advantages and limits, as well as the implementation in routine clinical practice and the learning curve for the user. The purpose of this prospective cohort-based study is to evaluate the performance of a 5G-based tele-robotic US system for abdominal and thyroid gland assessment in a cohort of healthy volunteers and outpatients, as well as assessing the learning curve and patient satisfaction. Results: 64 participants (23 male, 41 female) were consecutively included during the recruitment period, for a total of 51 abdominal and 37 thyroid gland US studies. The mean age was 45.23 ± 18.90 years old, and the body mass index of the abdominal cohort was 22.97 ± 2.95 kg/m ² . The learning curve estimated a minimum of 20 patients for abdominal tele-robotic US training, being almost non-existent in the thyroid gland cohort. All the variables showed no-statistical differences between standard US and tele-robotic US in the abdominal post-trained cohort except the visualization of the left kidney short axis and its interpolar length. Thyroid gland variables showed no statistical differences. The mean time of exploration for the tele-robotic US for abdomen and thyroid gland examinations were 18.33 ± 6.26 min and 4.64 ± 0.97 min respectively. Most participants (> 70%) felt comfortable and safe while being examined by the tele-robotic US. Conclusion: Tele-robotic US achieves equal performance in comparison with the standard US when evaluating abdominal structures in this cohort of patients, as well as a relatively fast learning curve and good patient satisfaction. The performance when assessing the thyroid gland is almost identical to the standard US, which makes it a strong first candidate for a future clinical implementation.