Publications by authors named "Joel G Fletcher"

Purpose: To evaluate correlation between terminal ileal (TI) stricture diagnosis at MR enterography (MRE) and ileocolonoscopy (IC) in patients with Crohn's disease (CD).

Methods: One hundred and four patients with CD (51% females; 41 ± 15 years) underwent IC and MRE within 3 months in this retrospective case-control study. Positive cases had TI strictures diagnosed by endoscopy (n = 35); or MRE (threshold small bowel dilation ≥ 3cm; n = 34).

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Article Synopsis
  • Ultrasound microvessel imaging (UMI) shows promise as a noninvasive method to assess microvessel structures in Crohn's disease (CD) by using a quantifiable metric called vessel-length ratio (VLR).
  • In a study involving 55 CD patients undergoing surgery, UMI's VLR had a strong correlation (R = 0.80) with pathological inflammation, significantly outperforming color flow imaging (CFI), which had a correlation of R = 0.59.
  • UMI not only distinguished between mild and non-mild inflammation more effectively than CFI, but also demonstrated superior performance in a subset of patients with strictures, indicating its potential utility in IBD imaging assessments.
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Spectral localizer images from photon-counting detector (PCD) CT can be used for bone mineral density (BMD) evaluation given their 2D-projectional nature and material decomposition capability. As all CT examinations include localizer images, this approach could allow opportunistic osteoporosis screening in patients undergoing clinically indicated imaging by PCD CT. To assess the utility of PCD-CT spectral localizer images for opportunistic derivation of area BMD (aBMD) values and T-scores, using dual-energy X-ray absorptiometry (DXA) as the reference standard.

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Objective: This study sought to determine consensus opinions from subspecialty radiologists and imaging physicists on the relative importance of image quality features in CT.

Methods: A prospective survey of subspecialty radiologists and medical physicists was conducted to collect consensus opinions on the relative importance of ten image quality features: axial sharpness, blooming, contrast, longitudinal sharpness, low contrast axial sharpness, metal artifact, motion, noise magnitude, noise texture, and streaking. The survey was first sent to subspecialty radiologists in volunteer leadership roles in the American College of Radiology and Radiological Society of North America, thereafter relying on snowball sampling.

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Background: SynthesiZed Improved Resolution and Concurrent nOise reductioN (ZIRCON) is a multi-kernel synthesis method that creates a single series of thin-slice computed tomography (CT) images displaying low noise and high spatial resolution, increasing reader efficiency and minimizing partial volume averaging.

Purpose: To compare the diagnostic performance of a single set of ZIRCON images to two routine clinical image series using conventional CT head and bone reconstruction kernels for diagnosing intracranial findings and fractures in patients with trauma or suspected acute neurologic deficit.

Material And Methods: In total, 50 patients underwent clinically indicated head CT in the ER (15 normal, 35 abnormal cases).

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Background And Purpose: Photon-counting detector CT (PCD-CT) is now clinically available and offers ultra-high-resolution (UHR) imaging. Our purpose was to prospectively evaluate the relative image quality and impact on diagnostic confidence of head CTA images acquired by using a PCD-CT compared with an energy-integrating detector CT (EID-CT).

Materials And Methods: Adult patients undergoing head CTA on EID-CT also underwent a PCD-CT research examination.

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Background: The first commercially available photon-counting-detector CT (PCD-CT) has been introduced for clinical use. However, its spectral performance on single- and dual-contrast imaging tasks has not been comprehensively assessed.

Purpose: To evaluate the spectral imaging performance of a clinical PCD-CT system for single-contrast material [iodine (I) or gadolinium (Gd)] and dual-contrast materials (I and Gd) in comparison with a dual-source dual-energy CT (DS-DECT).

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Article Synopsis
  • * A motion phantom was employed to simulate respiratory movements, comparing results from EID-CT (energy-integrating detector CT) and PCD-CT under static and moving conditions, specifically focusing on iodine concentration measurements and percent thrombus occlusion.
  • * Results indicated that EID-CT experienced significant motion artifacts and inaccuracies in iodine concentration during motion, while PCD-CT demonstrated stable measurements and consistency in estimating
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Purpose: Subtle liver metastases may be missed in contrast enhanced CT imaging. We determined the impact of lesion location and conspicuity on metastasis detection using data from a prior reader study.

Methods: In the prior reader study, 25 radiologists examined 40 CT exams each and circumscribed all suspected hepatic metastases.

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Objective: Pulmonary CT angiography (CTA) to detect pulmonary emboli can be performed using conventional dual-source CT with single-energy acquisition at high-pitch (high-pitch conventional CT), which minimizes motion artifacts, or routine-pitch, dual-energy acquisitions (routine-pitch conventional DECT), which maximize iodine signal. We compared iodine signal, radiation dose, and motion artifacts of pulmonary CTA between these conventional CT modalities and dual-source photon-counting detector CT with high-pitch, multienergy acquisitions (high-pitch photon-counting CT).

Methods: Consecutive clinically indicated pulmonary CTA exams were collected.

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Objective: To determine the accuracy of photon-counting-detector CT (PCD-CT) at deriving bone morphometric indices and demonstrate utility in vivo in the distal radius.

Methods: Ten cadaver wrists were scanned using PCD-CT and high-resolution peripheral quantitative CT (HRpQCT). Correlation between PCD-CT and HRpQCT morphometric indices was determined.

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Background Standardized methods to measure and describe Crohn disease strictures at CT enterography are needed to guide clinical decision making and for use in therapeutic studies. Purpose To assess the reliability of CT enterography features to describe Crohn disease strictures and their correlation with stricture severity. Materials and Methods A retrospective study was conducted in 43 adult patients with symptomatic terminal ileal Crohn disease strictures who underwent standard-of-care CT enterography at a tertiary care center at the Cleveland Clinic between January 2008 and August 2016.

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Article Synopsis
  • A study was conducted to evaluate the effectiveness of MR enterography in characterizing strictures caused by Crohn's disease and its correlation with stricture severity.
  • The research involved a retrospective analysis of patient data collected from two major clinics, examining various MR enterography features through assessments by trained radiologists over a significant time period.
  • Results indicated that certain features of strictures, like length and associated bowel dilation, showed strong reliability in measuring severity, which can help improve clinical decision-making and drug development for treating this condition.
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Fibrostenosis of the small bowel is common in patients with Crohn's disease. No consensus recommendations on definition, diagnosis and management in clinical practice are currently available. In this Consensus Statement, we present a clinical practice RAND/UCLA appropriateness study on the definition, diagnosis and clinical management of fibrostenosing Crohn's disease.

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Photon-counting detector CT (PCD-CT) is a new technology that has multiple diagnostic benefits including increased spatial resolution, iodine signal, and radiation dose efficiency, as well as multi-energy imaging capability, but which also has unique challenges in abdominal imaging. The purpose of this work is to summarize key features, technical parameters, and terms, which are common amongst current abdominopelvic PCD-CT systems and to propose standardized terminology (where none exists). In addition, user-selectable protocol parameters are highlighted to facilitate both scientific evaluation and early clinical adoption.

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Photon-counting CT (PCCT) is an emerging advanced CT technology that differs from conventional CT in its ability to directly convert incident x-ray photon energies into electrical signals. The detector design also permits substantial improvements in spatial resolution and radiation dose efficiency and allows for concurrent high-pitch and high-temporal-resolution multienergy imaging. This review summarizes key differences in PCCT image acquisition and image reconstruction compared with conventional CT; early evidence for the clinical benefit of PCCT for high-spatial-resolution diagnostic tasks in thoracic imaging, such as assessment of airway and parenchymal diseases, as well as benefits of high-pitch and multienergy scanning; anticipated radiation dose reduction, depending on the diagnostic task, and increased utility for routine low-dose thoracic CT imaging; adaptations for thoracic imaging in children; potential for further quantitation of thoracic diseases; and limitations and trade-offs.

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Background: Stricturing Crohn's disease (CD) occurs most commonly in the terminal ileum and poses a clinical problem. Cross-sectional imaging modalities such as intestinal ultrasound (IUS), computed tomography enterography (CTE), and magnetic resonance enterography (MRE) allow for assessment of the entire bowel wall and associated peri-enteric findings. Radiologic definitions of strictures have been developed for CTE and MRE; their reliability and responsiveness are being evaluated in index development programs.

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To improve quality of coronary CT angiography (CCTA) images using a generalizable motion-correction algorithm.. A neural network with attention gate and spatial transformer (ATOM) was developed to correct coronary motion.

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Purpose: To evaluate robustness of a radiomics-based support vector machine (SVM) model for detection of visually occult PDA on pre-diagnostic CTs by simulating common variations in image acquisition and radiomics workflow using image perturbation methods.

Methods: Eighteen algorithmically generated-perturbations, which simulated variations in image noise levels (σ, 2σ, 3σ, 5σ), image rotation [both CT image and the corresponding pancreas segmentation mask by 45° and 90° in axial plane], voxel resampling (isotropic and anisotropic), gray-level discretization [bin width (BW) 32 and 64)], and pancreas segmentation (sequential erosions by 3, 4, 6, and 8 pixels and dilations by 3, 4, and 6 pixels from the boundary), were introduced to the original (unperturbed) test subset (n = 128; 45 pre-diagnostic CTs, 83 control CTs with normal pancreas). Radiomic features were extracted from pancreas masks of these additional test subsets, and the model's performance was compared vis-a-vis the unperturbed test subset.

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