Browsing by Subject "Multimodal imaging"

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    Iatrogenic Spinal Deformity Following Spinal Intradural Arachnoid Cyst Fenestration Despite Minimal Access With Laminoplasty and Endoscopy in a Pediatric Patient
    (Cureus, 2022-02-09) Ordaz, Josue D.; Huh, Andrew; Desai, Virendra; Raskin, Jeffrey S.; Neurological Surgery, School of Medicine
    Spinal intradural arachnoid cysts (SAC) are non-neoplastic lesions that can cause spinal cord compression and present with myelopathy, radiculopathy, and/or back pain. Because these cysts typically span multiple levels, endoscopy could be a useful tool to avoid wide exposure. We present an 8-year-old patient with a history of gait imbalance and urinary incontinence who was found to have a SAC spanning C7 to T6 causing spinal cord compression. An osteoplastic laminoplasty was performed from T4 to T7 followed by ultrasonic verification of intracystic septations, dural opening, and cyst fenestration. A flexible endoscope was then introduced into the cystic cavity to guide complete rostral and caudal decompression of the arachnoid cyst. At six months follow-up, the patient was able to ambulate independently, but his urinary incontinence remained unchanged. Despite the combination of ultrasound and neuroendoscopy to minimize exposure, our patient suffered from worsening kyphosis from 36 degrees preoperative to 55 degrees postoperative and worsening scoliosis from 17 to 39 degrees which required treatment with a thoracolumbar sacral orthosis. Preoperative imaging demonstrated a reverse S-shaped scoliosis with the apex at T6 and T7 which were the levels included in the laminoplasty. This illustrates the need for careful preoperative risk stratification to avoid this postoperative complication.
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    Preoperative Embolization With Fused CT Angiography and Tractography Facilitates Safe Resection of a Spetzler-Martin Grade IV Arteriovenous Malformation
    (Cureus, 2021-12-24) Weyhenmeyer, Jonathan; Ordaz, Josue D.; Gadol, Aaron Cohen; Shah, Mitesh; Neurological Surgery, School of Medicine
    Brain arteriovenous malformations (BAVMs) are high-flow vascular lesions that have a propensity to rupture resulting in high rates of morbidity and mortality. Microsurgical resection of BAVMs is the standard of care for high-risk, resectable lesions. Multiple imaging modalities aid in the surgical planning and resection of high-grade BAVMs, but all have hidden variables that would prove useful if available. We present a 20-year-old male with a ruptured BAVM with concern for the involvement of the corticospinal tract (CST) and basal ganglia. We describe the melding of computed tomography angiography (CTA) and diffusion tensor imaging (DTI) in addition to preoperative embolization to aid in the planning and resection of a lesion close to eloquent structures. Post-operative CTA and DTI showed a total resection of the lesion with retained CST white matter tracts, and the patient retained the functional ability of the contralateral limbs. The combination of CTA, brain DTI, and preoperative embolization provides a framework to improve the safety of resection of BAVMs that occur near eloquent brain networks.
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    The Image Biomarker Standardization Initiative: Standardized Convolutional Filters for Reproducible Radiomics and Enhanced Clinical Insights
    (Radiological Society of North America, 2024) Whybra, Philip; Zwanenburg, Alex; Andrearczyk, Vincent; Schaer, Roger; Apte, Aditya P.; Ayotte, Alexandre; Baheti, Bhakti; Bakas, Spyridon; Bettinelli, Andrea; Boellaard, Ronald; Boldrini, Luca; Buvat, Irène; Cook, Gary J. R.; Dietsche, Florian; Dinapoli, Nicola; Gabryś, Hubert S.; Goh, Vicky; Guckenberger, Matthias; Hatt, Mathieu; Hosseinzadeh, Mahdi; Iyer, Aditi; Lenkowicz, Jacopo; Loutfi, Mahdi A. L.; Löck, Steffen; Marturano, Francesca; Morin, Olivier; Nioche, Christophe; Orlhac, Fanny; Pati, Sarthak; Rahmim, Arman; Rezaeijo, Seyed Masoud; Rookyard, Christopher G.; Salmanpour, Mohammad R.; Schindele, Andreas; Shiri, Isaac; Spezi, Emiliano; Tanadini-Lang, Stephanie; Tixier, Florent; Upadhaya, Taman; Valentini, Vincenzo; van Griethuysen, Joost J. M.; Yousefirizi, Fereshteh; Zaidi, Habib; Müller, Henning; Vallières, Martin; Depeursinge, Adrien; Pathology and Laboratory Medicine, School of Medicine
    Filters are commonly used to enhance specific structures and patterns in images, such as vessels or peritumoral regions, to enable clinical insights beyond the visible image using radiomics. However, their lack of standardization restricts reproducibility and clinical translation of radiomics decision support tools. In this special report, teams of researchers who developed radiomics software participated in a three-phase study (September 2020 to December 2022) to establish a standardized set of filters. The first two phases focused on finding reference filtered images and reference feature values for commonly used convolutional filters: mean, Laplacian of Gaussian, Laws and Gabor kernels, separable and nonseparable wavelets (including decomposed forms), and Riesz transformations. In the first phase, 15 teams used digital phantoms to establish 33 reference filtered images of 36 filter configurations. In phase 2, 11 teams used a chest CT image to derive reference values for 323 of 396 features computed from filtered images using 22 filter and image processing configurations. Reference filtered images and feature values for Riesz transformations were not established. Reproducibility of standardized convolutional filters was validated on a public data set of multimodal imaging (CT, fluorodeoxyglucose PET, and T1-weighted MRI) in 51 patients with soft-tissue sarcoma. At validation, reproducibility of 486 features computed from filtered images using nine configurations × three imaging modalities was assessed using the lower bounds of 95% CIs of intraclass correlation coefficients. Out of 486 features, 458 were found to be reproducible across nine teams with lower bounds of 95% CIs of intraclass correlation coefficients greater than 0.75. In conclusion, eight filter types were standardized with reference filtered images and reference feature values for verifying and calibrating radiomics software packages. A web-based tool is available for compliance checking.