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Aims: USP6 rearrangement underpins self‐limiting fibroblastic/myofibroblastic neoplasms, including nodular fasciitis (NF), myositis ossificans (MO), aneurysmal bone cyst (ABC), and related variants. The aim of this study was to characterise UPS6 and fusion partners in order to delineate the clinicopathological, genetic and bone‐forming features in such lesions of soft tissue (ST). Methods and results: Break‐apart fluorescence in‐situ hybridisation (FISH) validated USP6 rearrangement in 31 of 35 NF [comprising three of three fasciitis ossificans (FO) cases, seven of eight cellular variant of fibroma of tendon sheath (C‐FTS), four of six MO, three of three ST‐ABC, and two of two fibro‐osseous pseudotumours of digits (FOPD)]. As determined with FISH and reverse transcription polymerase chain reaction, MYH9–USP6 was the commonest fusion in four C‐FTS and 20 NF, including one intravascular case and two infantile (one retroperitoneal) cases. The presence of MYH9–USP6 confirmed the diagnosis of two NFs> 50 mm with prominent ischaemic necrosis. COL1A1–USP6 was predominant in ossifying lesions, including all FO, MO, ST‐ABC and FOPD with identified partner genes, and was also present in non‐ossifying head and neck NF (HN‐NF) and C‐FTS in two cases each. A cervical NF of a 14‐month‐old girl harboured the novel COL1A2–USP6. Ossifying lesions showed considerable genetic and morphological overlaps. Sharing COL1A1–USP6, FO and FOPD showed similar central or haphazard bone matrix deposition. Besides zonation of outward bone maturation, four COL1A1–USP6‐positive MO had incipient to sieve‐like pseudocysts reminiscent of ST‐ABC. Conclusion: MYH9–USP6 is present in some C‐FTS and most NF, including rare variants, but is unrelated to bone formation. All bone‐forming USP6‐rearranged lesions adopt COL1A1 as the 5′ partner, indicating close genetic kinships. However, COL1A1/COL1A2 also contributes to the pathogenesis of minor subsets of non‐ossifying USP6‐rearranged HN‐NF and C‐FTS. [ABSTRACT FROM AUTHOR]

Purpose: To improve the SNR efficiency and reduce the T2 blurring of 3D rapid acquisition with relaxation enhancement stack‐of‐spiral arterial spin labeling imaging by using variable refocusing flip angles and k‐space filtering. Methods: An algorithm for determining the optimal combination of variable flip angles and filtering correction is proposed. The flip angles are designed using extended phase graph physical simulations in an analytical and global optimization framework, with an optional constraint on deposited power. Optimal designs for correcting to Hann and Fermi window functions were compared with conventional constant amplitude or variable flip angle only designs on 6 volunteers. Results: With the Fermi window correction, the proposed optimal designs provided 39.8 and 27.3% higher SNR (P < .05) than conventional constant amplitude and variable flip angle designs. Even when power deposition was limited to 50% of the constant amplitude design, the proposed method outperformed the SNR (P < .05) of these 2 conventional approaches by 32.5 and 20.7%. The sharpness and the contrast between gray and white matter were improved with the k‐space filtering correction for all of the flip angle designs. The improvements were moderate for the Hann window correction. Conclusion: This work demonstrates that variable flip angles can be derived as the output of an optimization problem. The combined design of variable flip angle and k‐space filtering provided superior SNR to designs primarily emphasizing either approach singly. [ABSTRACT FROM AUTHOR]

Purpose: The present study aims to assess the short-term clinical outcomes and safety of transarterial embolization (TAE) for symptomatic hand osteoarthritis (OA) refractory to conservative treatment., Methods: The present retrospective cohort pilot study included nine patients who underwent TAE for symptomatic OA-associated hand pain in a single tertiary center between November 2022 and January 2023. The baseline and post-procedural OA-associated hand pain and function were assessed using the visual analog scale (VAS) and the Australian Canadian Hand Osteoarthritis Index (AUSCAN). The use of conservative treatment and pain medications was also recorded. Post-procedural adverse events were evaluated according to the Society of Interventional Radiology classification., Results: Compared with the baseline, the overall VAS scores were significantly decreased at 1-week, 1-month, 3-months, and 6-months after TAE (76 ± 15 mm versus 34 ± 18 mm, P < 0.001; 32 ± 11 mm, P < 0.001; 21 ± 15 mm, P < 0.001; 18 ± 19 mm, P = 0.002). Similarly, improvement in the mean total AUSCAN scores (22.0 ± 10.0 versus 13.2 ± 6.6, P = 0.007; 14.11 ± 7.3, P = 0.004; 9.8 ± 6.8, P = 0.004; 9.3 ± 7.4, P = 0.011) were documented. The use of other conservative treatment methods also gradually decreased. There were no severe adverse events reported during the follow-up period., Conclusion: TAE is a feasible and safe treatment method for symptomatic hand OA refractory to conservative treatment. This minimally invasive procedure effectively relieves debilitating OA-associated joint pain and restores hand function with a durable treatment effect.

Aims: Intracranial myxoid mesenchymal tumors (IMMTs) with fusions between EWSR1/FUS and CREB transcription factors have morphologic overlap with myxoid angiomatoid fibrous histiocytoma (mAFH) and myoepithelial tumor/carcinoma (MET/MEC). We aimed to study the clinicopathologic and genetic spectrum of extracranial IMMT-like tumors and their relationships with mAFH and MET/MEC., Methods: Twelve extracranial tumors harboring EWSR1/FUS-CREB fusions across different histologic groups were characterized using RNA sequencing, FISH and/or RT-PCR., Results: There were 4 IMMT-like neoplasms, 3 MET/MECs, and 5 mAFHs from the tibia (n=1), oral cavity (n=2), and soft tissues (n=9; 5 in the extremities), harboring EWSR1-ATF1 in 4 cases, FUS-CREM and EWSR1-CREM in 3 each, and EWSR1-CREB1 in 2. Multinodular growth, reticular/cording/trabecular arrangements, myxocollagenous matrix, and lymphocytic infiltrates variably prevailed among the 3 groups. mAFHs were characterized by cells with syncytial cytoplasm. IMMT-like neoplasms and MET/MECs shared cells with distinct boundaries, but only MET/MECs expressed GFAP and/or S100. MUC4 and ALK were expressed in some IMMT-like neoplasms (2/4; 2/4) and mAFH (2/5; 1/5). Pan-TRK reactivity was observed in two IMMT-like neoplasms with upregulated NTRK3 mRNA and one MEC. Local recurrences, typically ≥ 12 months postoperatively, developed in 2/3 IMMT-like neoplasms, 1/2 MET/MECs, and 0/4 mAFHs with follow-up. No definite associations were found between fusion types and histology, immunoprofile or outcome., Conclusions: We demonstrated the similarities and differences among 3 extracranial myxocollagenous tumor groups sharing EWSR1/FUS-CREB fusions. Oral IMMT-like neoplasms harboring FUS-CREM or EWSR1-ATF1 and FUS-CREM-positive., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Purpose: To improve the SNR efficiency and reduce the T 2 blurring of 3D rapid acquisition with relaxation enhancement stack-of-spiral arterial spin labeling imaging by using variable refocusing flip angles and k-space filtering., Methods: An algorithm for determining the optimal combination of variable flip angles and filtering correction is proposed. The flip angles are designed using extended phase graph physical simulations in an analytical and global optimization framework, with an optional constraint on deposited power. Optimal designs for correcting to Hann and Fermi window functions were compared with conventional constant amplitude or variable flip angle only designs on 6 volunteers., Results: With the Fermi window correction, the proposed optimal designs provided 39.8 and 27.3% higher SNR (P < .05) than conventional constant amplitude and variable flip angle designs. Even when power deposition was limited to 50% of the constant amplitude design, the proposed method outperformed the SNR (P < .05) of these 2 conventional approaches by 32.5 and 20.7%. The sharpness and the contrast between gray and white matter were improved with the k-space filtering correction for all of the flip angle designs. The improvements were moderate for the Hann window correction., Conclusion: This work demonstrates that variable flip angles can be derived as the output of an optimization problem. The combined design of variable flip angle and k-space filtering provided superior SNR to designs primarily emphasizing either approach singly., (© 2018 International Society for Magnetic Resonance in Medicine.)