AbstractObjectiveLimited evidence guides the optimal timing of treatment after the detection of tumor growth during the observation of sporadic vestibular schwannoma (VS). The current work aimed to inform the timing of radiosurgical intervention based on an analysis of patient outcomes among those who ultimately failed stereotactic radiosurgery (SRS) and underwent salvage microsurgery.Study DesignA historical cohort study.SettingSeven centers across the United States and Norway.MethodsAdults with sporadic VS who underwent salvage microsurgery following failed primary SRS were included. The primary outcome of interest was the association between tumor size at the time of primary SRS and the ability to achieve gross total resection (GTR) and maintain postoperative House–Brackmann (HB) facial nerve grade I at the last follow‐up after salvage microsurgery.ResultsAmong 96 patients, the median (interquartile range [IQR]) cerebellopontine angle (CPA) tumor size at primary SRS was 14.5 mm (10.0‐19.0). Each 1‐mm increase in CPA tumor size at the time of primary SRS was associated with a 13% increased likelihood of near‐total/subtotal resection or most recent postoperative HB grade >I (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.05‐1.21, P = .001), with an optimal tumor size threshold to distinguish this outcome of 12 mm of CPA extension (c‐index 0.73). Similarly, for each 1‐mm increase in CPA tumor size at the time of primary SRS, a 9% increase in any postoperative complication with salvage microsurgery was observed (OR 1.09, 95% CI 1.02‐1.15, P = .009).ConclusionCorroborated by size threshold surveillance data informing the timing of primary microsurgical resection, the current study suggests that VS outcomes are optimized when primary radiosurgical intervention is undertaken on growing tumors when they harbor 10–15 mm of cerebellopontine angle extension or less.
AKIRA: Deep learning tool for image standardization, implant detection and arthritis grading to establish a radiographic registry in patients with anterior cruciate ligament injuries
Abstract Purpose Developing large‐scale, standardized radiographic registries for anterior cruciate ligament (ACL) injuries with artificial intelligence (AI) tools can enhance personalized orthopaedics. We propose deploying Artificial Intelligence for Knee Imaging Registration and Analysis (AKIRA), a trio of deep learning (DL) algorithms, to automatically classify and annotate radiographs. We hypothesize that algorithms can efficiently organize radiographs based on laterality, projection, identify implants and classify osteoarthritis (OA) grade. Methods A collection of 20,836 knee radiographs from all time points of treatment (mean orthopaedic follow‐up 70.7 months; interquartile range [IQR]: 6.8–172 months) were aggregated from 1628 ACL‐injured patients (median age 26 years [IQR: 19–42], 57% male). Three DL algorithms (EfficientNet, YOLO [You Only Look Once] and Residual Network) were employed. Radiograph laterality and projection (anterior‐posterior [AP], lateral, sunrise, posterior‐anterior, hip–knee–ankle and Camp‐Coventry intercondylar [notch]) were labelled by a DL model. Manually provided labels of metal fixation implants were used to develop a DL object detection algorithm. The degree of OA, both as measured by specific Kellgren–Lawrence (KL) grades, as well as based on a binarized label of OA (defined as KL Grade ≥2), on standing AP radiographs were classified using a DL algorithm. Individual model performances were evaluated on a subset of images prior to the deployment of AKIRA to registry construction using all ACL radiographs. Results The classification algorithms showed excellent performance in classifying radiographic laterality (F1 score: 0.962–0.975) and projection (F1 score: 0.941–1.0). The object detection algorithm achieved high precision–recall (area under the precision‐recall curve: 0.695–0.992) for identifying various metal fixations. The KL classifier reached concordances of 0.39–0.40, improving to 0.81–0.82 for binary OA labels. Sequential deployment of AKIRA following internal validation processed and labelled all 20,836 images with the appropriate views, implants, and the presence of OA within 88 min. Conclusion AKIRA effectively automated the classification and object detection in a large radiograph cohort of ACL injuries, creating an AI‐enabled radiographic registry with comprehensive details on laterality, projection, implants and OA. Study Design Cross‐sectional study. Level of Evidence Level IV.
Retraction Note: Management of Spontaneous Labor in Primigravidae: Labor Scale versus WHO Partograph (SLiP Trial) Randomized Controlled Trial
AbstractAlthough bronchial artery embolization (BAE) initially emerged as a critical minimally invasive image-guided procedure to manage massive hemoptysis regardless of underlying etiologies, there has been a growing interest in BAE to treat pulmonary malignancies within recent years. This article provides an in-depth exploration of bronchial artery anatomy, pathologies, imaging modalities in guiding effective BAE, and procedural pearls for successful intervention. The complexity of bronchial artery anatomy, including its variations and potential complications during embolization, necessitates thorough understanding and precise procedural techniques to optimize patient outcomes and minimize risks.
Spectral performance for iodine quantification of a dual‐source, dual‐kV photon counting detector CT
Abstract Background Multi‐energy CT (MECT) enables quantification of material concentrations by measuring linear attenuation coefficient line integrals with multiple x‐ray spectra. Photon counting detector (PCD)‐CT utilizes a detector‐based approach for MECT that can suffer from substantial spectral overlap, resulting in amplified material quantification noise. Dual‐source dual‐kV approaches for MECT are currently utilized in some energy‐integrating detector (EID)‐CT systems and can potentially be utilized with PCD‐CT for improved spectral separation. Purpose To evaluate the iodine quantification performance of a novel dual‐source (DS)‐PCD‐CT scan mode and compare to single‐source (SS)‐PCD‐CT and DS‐EID‐CT. Materials and Methods A 30 cm × 40 cm solid water phantom with four iodine inserts (2, 5, 10, and 15 mg/mL) was scanned with the three spectral modalities: SS‐PCD‐CT with two energy thresholds, DS‐PCD‐CT (90/Sn150 kV), and DS‐EID‐CT (90/Sn150 kV). For each modality, full‐dose (12 mGy) and half‐dose scans were acquired, and images were reconstructed with filtered back‐projection using a quantitative (Qr40) kernel. When scanning in a DS configuration, the total radiation dose budget is split between two detectors, increasing the strength of a signal‐dependent filter compared to a SS acquisition. To account for this effect, the modulation transfer function (MTF) for each modality was measured from a 0.05 mm tungsten wire. A linear spatial filter was applied to the SS images to match their MTF to that of the DS images. The resulting high‐ and low‐energy images were input into an image‐domain least squares material decomposition algorithm with iodine and water as the two basis materials. Iodine quantification accuracy and noise measured from the iodine basis images were used as figures of merit, and t‐tests used to compare between modalities. Results The 10% MTF cutoffs were 0.56, 0.57, 0.60, and 0.57 lp/mm for DS‐EID‐CT, DS‐PCD‐CT, SS‐PCD‐CT, and SS‐PCD‐CT after MTF‐matching, respectively, with the SS‐PCD‐CT MTF cutoff dropping to 0.58 lp/mm at half‐dose. Without accounting for the signal‐dependent filter by matching the MTFs, the noise in iodine material basis images from SS‐PCD‐CT was 10% higher than that of DS‐EID‐CT. After matching the MTFs, the noise in the SS‐PCD‐CT iodine image was 9%–22% lower than that of the DS‐EID‐CT. The lowest iodine image noise was from the DS‐PCD‐CT, which was 39%–41% lower than the DS‐EID‐CT. The DS‐PCD‐CT noise magnitude was significantly different from the other modalities. Mean iodine quantification accuracy across all measured concentrations was within 5% for all modalities at full dose, but was only below 5% for the DS‐PCD‐CT at half‐dose. Conclusions SS‐PCD‐CT with two energy thresholds outperformed DS‐EID‐CT in terms of image noise in iodine basis images when spatial resolution was matched. DS‐PCD‐CT gave the lowest noise due to the combination of PCD technology and improved spectral separation from the different x‐ray spectra.
Adjuvant Radiation Therapy or Observation With or Without Early Salvage Radiation Therapy for Men With Node-Positive Prostate Cancer After Surgery and Negative Preoperative Conventional Imaging: A Multicenter Study
Purpose To establish consensus statements via a modified Delphi process about ethics, transparency, regulation, and best practices for the use of orthobiologics in clinical practice for musculoskeletal pathology. Methods A consensus process on the regulation of orthobiologics at the provider level was conducted using a modified Delphi technique. Twenty orthopaedic surgeons, sports medicine physicians, or basic scientists participated. Each participant was a Biologic Association member organization representative and asked to participate because of their active interest in the field of orthobiologics. Levels of consensus were delineated according to the number of votes for each statement: no consensus, <80%; consensus, 80% to 89%; strong consensus, 90% to 99%; unanimous, 100%. Results The 26 consensus statements on orthobiologics resulted in 14 achieving unanimous consensus, 8 achieving strong consensus, 3 achieving consensus, and 1 did not achieve consensus. Overall, 85% of the statements reached either a unanimous or strong consensus. Of the statements regarding communication and transparency, 9 reached unanimous consensus, including information to convey and helpful tools to describe current orthobiologics, persistent misinformation, use of the word “stem cells,” “off‐label” use, and problems with the present regulatory environment. Five statements discussing the regulation of novel orthobiologics achieved unanimous consensus. These statements highlighted research regulation, safety, and suggested improvements to regulatory issues. The statement that did not achieve any consensus was on the regulatory processes that should be in place by an institution providing novel orthobiologic treatments. No statement reached a unanimous agreement on cost or ethical considerations. Conclusions This study successfully identified key consensus statements emphasizing the importance of ethics, transparency, and regulation in the use of orthobiologics, with 85% of statements reaching unanimous or strong consensus. These findings underscore the need for standardized communication, improved regulatory frameworks, and enhanced safety measures while highlighting persistent challenges in addressing cost and ethical considerations. Level of Evidence Level V, expert opinion.