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Feasibility of thin-slice, low noise images created using multi-kernel synthesis to replace multiple image series in head CT

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ACTA RADIOLOGICA 2024年第11期65卷 1411-1421页

作者： Inoue, Akitoshi Diehn, Felix E. Nagelschneider, Alex A. Passe, Theodore J. DeLone, David R. Nelson, Brandon J. Cardona, Daniel G. Gomez Huber, Nathan R. Missert, Andrew D. Yu, Lifeng Johnson, Matthew P. Holmes, David R. Lee, Yong S. Thorne, Jamison E. McCollough, Cynthia H. Fletcher, Joel G. Mayo Clin Dept Radiol 200 First St SW Rochester MN 55905 USA Mayo Clin Dept Quantitat Hlth Sci Rochester MN USA Mayo Clin Dept Physiol Biomed Engn Rochester MN USA Shiga Univ Med Sci Dept Radiol Shiga Japan Gunderson Hlth Syst Dept Imaging La Crosse WI USA

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 *** 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 *** and Methods In total, 50 patients underwent clinically indicated head CT in the ER (15 normal, 35 abnormal cases). A non-reader neuroradiologist established the reference standard. Three neuroradiologists reviewed two routine clinical series (head and bone kernels) and a single ZIRCON series, detecting intracranial findings or fractures and rating confidence (0-100). Sensitivity, specificity, and jackknife free-response receiver operating characteristic (JAFROC) figure of merit (FOM) were compared (limit of non-inferiority: -0.10).Results ZIRCON and conventional images demonstrated comparable performance for fractures (sensitivity: 51.5% vs. 54.5%;specificity: 40.2% vs. 34.2%) and intracranial findings (sensitivity: 88.2% vs. 91.4%;specificity: 77.2% vs. 73.7%).The estimated difference of JAFROC FOM demonstrated ZIRCON non-inferiority for acute pathologies overall (0.003 [95% CI=-0.051-0.057]) and fractures (0.048 [95% CI=-0.050-0.145]) but not for intracranial findings alone (-0.024 [95% CI=-0.100-0.052]).Conclusion Thin-slice, low noise, and high spatial resolution images can be created to display intracranial findings and fractures replacing multiple images series in head CT with similar performance. Future studies in more patients and further algorithmic development are warranted.

关键词： Computed tomography image postprocessing trauma hemorrhage

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Deep learning-based noise reduction for coronary CT angiography: using four-dimensional noise-reduction images as the ground truth

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ACTA RADIOLOGICA 2023年第5期64卷 1831-1840页

作者： Kobayashi, Takuma Nishii, Tatsuya Umehara, Kensuke Ota, Junko Ohta, Yasutoshi Fukuda, Tetsuya Ishida, Takayuki Osaka Univ Grad Sch Med Dept Med Phys & Engn Suita Japan Natl Cerebral & Cardiovasc Ctr Dept Radiol Suita Japan Natl Inst Quantum Sci & Technol QST QST Hosp Dept Med Technol Med Informat Sect Chiba Japan Natl Inst Quantum Sci & Technol Inst Quantum Med Sci Dept Mol Imaging & Theranost Appl MRI Res Chiba Japan Osaka Univ Dept Med Phys & Engn Grad Sch Med 1-7 Yamadaoka Suita Osaka 5650871 Japan

Background To assess low-contrast areas such as plaque and coronary artery stenosis, coronary computed tomography angiography (CCTA) needs to provide images with lower noise without increasing radiation doses. Purpose To develop a deep learning-based noise-reduction method for CCTA using four-dimensional noise reduction (4DNR) as the ground truth for supervised learning. Material and Methods \We retrospectively collected 100 retrospective ECG-gated CCTAs. We created 4DNR images using non-rigid registration and weighted averaging three timeline CCTA volumetric data with intervals of 50 ms in the mid-diastolic phase. Our method set the original reconstructed image as the input and the 4DNR as the target image and obtained the noise-reduced image via residual learning. We evaluated the objective image quality of the original and deep learning-based noise-reduction (DLNR) images based on the image noise of the aorta and the contrast-to-noise ratio (CNR) of the coronary arteries. Further, a board-certified radiologist evaluated the blurring of several heart structures using a 5-point Likert scale subjectively and assigned a coronary artery disease reporting and data system (CAD-RADS) category independently. Results DLNR CCTAs showed 64.5% lower image noise (P < 0.001) and achieved a 2.9 times higher CNR of coronary arteries than that in original images, without significant blurring in subjective comparison (P > 0.1). The intra-observer agreement of CAD-RADS in the DLNR image was excellent (0.87, 95% confidence interval = 0.77-0.99) with original CCTAs. Conclusion Our DLNR method supervised by 4DNR significantly reduced the image noise of CCTAs without affecting the assessment of coronary stenosis.

关键词： Coronary computed tomography angiography noise reduction deep learning convolutional neural network image postprocessing

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Diagnostic Imaging of Oral and Maxillofacial Anatomy and Pathology

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VETERINARY CLINICS OF NORTH AMERICA-SMALL ANIMAL PRACTICE 2022年第1期52卷 67-105页

作者： Villamizar-Martinez, Lenin A. Tsugawa, Anson J. North Carolina State Univ Dept Clin Sci Coll Vet Med 1060 William Moore Dr Raleigh NC 27607 USA Dog & Cat Dentist Inc 9599 Jefferson Blvd Culver City CA 90232 USA

This article describes the technical principles and indications for the most often encountered diagnostic imaging modalities in veterinary dentistry and oral surgery; with extensive coverage of intraoral (and extraoral) dental radiographic imaging and interpretation through detailed example figures of common dental and maxillofacial diseases in the dog and cat. Multidetector/multislice computed tomography (MDCT/MSCT) and emergent technologies such as cone-beam computed tomography (CBCT) are presented here in detail. Magnetic resonance imaging (MRI) and diagnostic ultrasound, which are used less frequently, are briefly discussed.

关键词： Intraoral radiography Dental digital imaging equipment image postprocessing Dental radiograph interpretation CT CBCT maxillofacial skeleton CBCT high spatial resolution Multiplanar reconstruction maxillofacial trauma 3D printing OMFS MRI TMJ articular disc Orbital ultrasound retrobulbar disease

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IVIM MRI - Evolution from DWI, Observations, Challenges and Relevance of pre and post processing phases 5

IVIM MRI - Evolution from DWI, Observations, Challenges and ...

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5th International Conference on Electrical, Electronics, Communication, Computer Technologies and Optimization Techniques (ICEECCOT)

作者： Raju, Jini Amma, Ushadevi C. John, Ansamma APJ Abdul Kalam Technol Univ Thangal Kunju Musaliar Coll Engn Dept Comp Sci & Engn Kollam Kerala India Amrita Vishwa Vidhyapeetham Dept Elect & Commun Engn Amritapuri Campus Kollam Kerala India

ISBN: (纸本)9781665432726

Intravoxel Incoherent Motion Magnetic Resonance Imaging(IVIM MRI) is a quantitative, non invasive imaging technique that exploits perfusion and diffusion properties of tissues. Even though IVIM has grown in popularity in recent years, there is still a lot of research being done in the field, from image acquisition to disease diagnosis. This paper explores various challenges faced by researchers as well as clinicians during the IVIM image acquisition and postprocessing phases, through experimental analysis. The numerous issues associated with image acquisition phase are the properly fixing up of b value count, absolute b values, threshold b value and the highest achievable b value. The selection of image formats and correlation between slices in IVIM MRI images are other significant challenges during the image acquisition phase. The selection of appropriate fitting algorithm, for the estimation of IVIM parameters, is the major challenge in the post processing phase which is addressed by selecting an algorithm based on the quality off, D and D* maps generated. Since IVIM is in its infancy stage, the lack of real IVIM images is one of the major hurdles in IVIM research and hence simulated data is also used in addition to the available real dataset.

关键词： Diffusion Weighted Imaging Intravoxel Incoherent Motion Imaging Fitting algorithm image postprocessing

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What is the hemodynamic effect of the Woven EndoBridge? An in vivo quantification using time-density curve analysis

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NEURORADIOLOGY 2020年第8期62卷 1043-1050页

作者： Goelitz, Philipp Luecking, Hannes Hoelter, Philip Knossalla, Frauke Doerfler, Arnd Univ Erlangen Nurnberg Dept Neuroradiol Schwabachanlage 6 D-91054 Erlangen Germany Univ Erlangen Nurnberg Dept Neurol Erlangen Germany

Purpose Using the Woven EndoBridge (WEB) for aneurysm treatment has emerged as endovascular approach aiming for flow disruption in aneurysm sac. Since quantifiable data confirming the hemodynamic effect are lacking, we investigated in vivo aneurysmal flow alterations using time-density curve (TDC) analysis. Additionally, we evaluated whether flow parameters could be identified as independent factor to predict aneurysm occlusion. Methods Forty cerebral aneurysm patients treated with WEB were enrolled. Pre- and postinterventional digital subtraction angiography series were postprocessed and TDCs generated. TDCs were quantified calculating the parameters aneurysmal inflow velocity, outflow velocity, mean flow velocity, and relative time-to-peak (rTTP) of aneurysm filling. Pre- and postinterventional values were compared and related to occlusion rate. Results WEB implanting induced highly significant rTTP prolongation by 52% (p = 0.001) and highly significant decrease of aneurysmal inflow, outflow, and mean flow velocity (p < 0.001). While outflow velocity was reduced by 49%, inflow velocity was reduced by 33% only. No statistically significant difference between the occluded and the non-occluded group was observed. No flow parameter reached significance level concerning predicting aneurysm occlusion. Conclusion Flow quantification confirms a significant flow-disrupting effect of WEB reducing more the outflow than the inflow velocity. In our small cohort, no flow parameter reached statistical significance to show predictive value regarding complete aneurysm occlusion. The hemodynamic effect of WEB is on comparable level to flow-diverting stents meaning that aneurysm closure can be delayed. In case of only slight inflow changes and high aneurysmal hemodynamic stress, some aneurysms might not be adequately protected in the short term.

关键词： Aneurysm Hemodynamics Intrasaccular flow diverter Digital subtraction angiography Time-density curve image postprocessing

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Carotid and cerebrovascular dual-energy computed tomography angiography: Optimization of window settings for virtual monoenergetic imaging reconstruction

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EUROPEAN JOURNAL OF RADIOLOGY 2020年 130卷 109166-109166页

作者： D'Angelo, Tommaso Lenga, Lukas Arendt, Christophe T. Bucher, Andreas M. Peterke, Julia L. Caruso, Damiano Mazziotti, Silvio Ascenti, Giorgio Blandino, Alfredo Othman, Ahmed E. Martin, Simon S. Albrecht, Moritz H. Bodelle, Boris Vogl, Thomas J. Wichmann, Julian L. Univ Hosp Frankfurt Dept Diagnost & Intervent Radiol Theodor Stern Kai 7 D-60590 Frankfurt Germany G Martino Univ Hosp Messina Dept Biomed Sci & Morphol & Funct Imaging Via Consolare Valeria 1 I-98100 Messina Italy La Sapienza Univ Hosp Dept Radiol Sci Oncol & Pathol Sci Latina Italy Eberhard Karls Univ Tuebingen Univ Hosp Tubingen Dept Diagnost & Intervent Radiol Tubingen Germany

Purpose: Dedicated post-processing of dual-energy computed tomography angiography (DE-CTA) datasets has been shown to allow for increased vascular contrast. The goal of our study was to define optimal window settings for displaying virtual monoenergetic images (VMI) reconstructed from dual-energy carotid and cerebrovascular DE-CTA. Methods: Fifty-seven patients who underwent clinically-indicated carotid and cerebrovascular third-generation dual-source DE-CTA were retrospectively evaluated. Standard linearly-blended (M_0.6), 70-keV traditional VMI (M70), and 40-keV noise-optimized VMI (M40+) reconstructions were analyzed. For M70 and M40+ datasets, the subjectively best window setting (width and level, B-W/L) was independently determined by two observers and subsequently related with aortic arch attenuation to calculate optimized values (O-W/L) using linear regression. Subjective evaluation of image quality (IQ) between W/L settings were assessed by two additional readers. Repeated measures analysis of variance were performed to compare W/L settings and IQ indices between M_0.6, M70, and M40+. Results: B-W/L and O-W/L for M70 were 580/210 and 560/200, and for M40+ were 1630/570 and 1560/550, respectively, higher than standard DE-CTA W/L settings (450/100). Highest subjective scores were observed for M40+ regarding overall IQ (all p < 0.001). Conclusion: Application of O-W/L settings is mandatory to optimize subjective IQ of VMI reconstructions of DE-CTA.

关键词： Carotid disease Dual-energy Computed tomography Computed tomography angiography image postprocessing

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2D transform-domain Fourier filters for eliminating microsaccade noise in en face optical coherence tomography angiography 3

2D transform-domain Fourier filters for eliminating microsac...

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Conference on Optical Coherence Imaging Techniques and Imaging in Scattering Media III

作者： Yang, Jianlong Fang, Liyang Hu, Yan Zhao, Yitian Zheng, Yalin Liu, Jiang Chinese Acad Sci Cixi Inst Biomed Engn Beijing Peoples R China Univ Liverpool Dept Eye & Vis Sci Liverpool Merseyside England

ISBN: (纸本)9781510628502

Microsaccade noise is fast-scan-directional bright short lines in en face optical coherence tomography angiography images. We propose to use 2D Fourier filters in different transform domains including Fourier, wavelet, and nonsubsampled contourlet domains to eliminate this kind of noise. We used image entropy and vessel density as the metrics to evaluate their performance on noise elimination, we found that filtering after the nonsubsampled contourlet transform (NSCT) was the best choice among these approaches. For vessel preservation, the wavelet-domain filtering has the advantage of keeping signal-to-noise ratio while the NSCT filtering can preserve structure similarity to the most extent.

关键词： Optical coherence tomography angiography ocular imaging image postprocessing denoising

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Spectral Detector Computed Tomography Pulmonary Angiography: Improved Diagnostic Assessment and Automated Estimation of Window Settings Angiography of Pulmonary Arteries From Novel Spectral Detector Computed Tomography Provides Improved image Quality if Settings are Adjusted

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JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 2018年第6期42卷 850-857页

作者： Hokamp, Nils Grosse Kessner, Rivka Van Hedent, Steven Graner, Frank Philipp Gupta, Amit Gilkeson, Robert Univ Hosp Cleveland Med Ctr Dept Radiol 11000 Euclid Ave Cleveland OH 44106 USA Case Western Reserve Univ Dept Radiol Cleveland OH 44106 USA Univ Hosp Brussels Dept Radiol Brussels Belgium

Objective This study aimed to evaluate image quality (IQ) of virtual monoenergetic images (VMIs) from novel spectral detector computed tomography angiography of the pulmonary arteries and to identify appropriate window settings for each kiloelectron volt level. Materials Forty consecutive patients were included in this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study. Signal- and contrast-to-noise ratios were calculated within the pulmonary trunk, and pulmonary/lobar/segmental arteries were calculated. The IQ and diagnostic certainty were rated by 2 radiologists on 5-point scales. In addition, they recorded appropriate window settings (center/width) that were linearly modeled against attenuation within the pulmonary trunk to generate generable results. Results Signal- and contrast-to-noise ratios, IQ, and diagnostic certainty are significantly increased in low-kiloelectron volt VMIs (60 keV). Interrater agreement was excellent (? = 0.89). We developed 2 linear models (R-2: 0.91-0.97 and R-2: 0.43-0.91, respectively, P 0.01), that suggest appropriate window settings. Conclusions The VMIs from spectral detector computed tomography improve objective and subjective IQ in angiography of the pulmonary arteries, if window settings are adjusted;they can be automatically estimated using reported linear models.

关键词： dual-energy computed tomography spectral detector computed tomography image quality image postprocessing window settings pulmonary emboli

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Lesion-oriented epilepsy surgery

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ZEITSCHRIFT FUR EPILEPTOLOGIE 2018年第2期31卷 134-139页

作者： von Lehe, M. Parpaley, Y. Kowoll, A. Wehner, T. Wellmer, J. Univ Klinikum Knappschaftskrankenhaus Bochum Klin Neurochirurg Ruhr Epileptol Schornau 23-25 D-44892 Bochum Germany Univ Klinikum Knappschaftskrankenhaus Bochum Inst Radiol Bochum Germany Univ Klinikum Knappschaftskrankenhaus Bochum Klin Neurol Ruhr Epileptol Bochum Germany

Background. State of the art magnetic resonance imaging (MRI) enables epilepsy surgery to focus more and more on epileptogenic lesions. Beyond its mere detection, the precise definition of the lesion borders is important for lesion-based surgical resection or lesion-focused thermal coagulation. Objectives. To describe modern MRI techniques to delineate lesion borders as precisely as possible and to integrate these into the planning and performance of epilepsy surgery. Material and methods. Expert recommendations illustrated by an example of focal cortical dysplasia (FCD). Results. For lesion-orientated epilepsy surgery, 3 T MRI is preferred over 1.5 T MRI. For epileptogenic lesions with solid tissue preoperative sequence. New sequences, such as ZOOMit may be superior for some types of lesions (FCD IIB). Planar, curvilinear and radial image reconstructions help to visualize the borders of the lesions. Importing this information into neuronavigation systems makes it available for the neurosurgeon for stereotactic and open neuronavigation-based resection surgery. Conclusion. Lesion-oriented epilepsy surgery should be carried out based on the best available preoperative imaging techniques including image postprocessing.

关键词： Magnetic resonance imaging (MRI) Epileptogenic lesion Epilepsy surgery image postprocessing Neuronavigation

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Real-Time, In Vivo Monitoring, and Quantitative Assessment of Intra-Arterial Vasospasm Therapy

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NEUROCRITICAL CARE 2016年第1期25卷 40-46页

作者： Goelitz, Philipp Kaschka, Iris Lang, Stefan Roessler, Karl Knossalla, Frauke Doerfler, Arnd Univ Erlangen Nurnberg Dept Neuroradiol Schwabachanlage 6 D-91054 Erlangen Germany Univ Erlangen Nurnberg Dept Neurosurg Erlangen Germany Univ Erlangen Nurnberg Dept Neurol Erlangen Germany

Our study aimed to evaluate whether the effect of an intra-arterial vasospasm therapy can be assessed quantitatively by in vivo blood flow analysis using the postprocessing algorithm parametric color coding (PCC). We evaluated 17 patients presenting with acute clinical deterioration due to vasospasm following subarachnoidal hemorrhage treated with intra-arterial nimodipine application. Pre- and post-interventional DSA series were post-processed by PCC. The relative time to maximum opacification (rTmax) was calculated in 14 arterially and venously located points of interest. From that data, the pre- and post-interventional cerebral circulation time (CirT) was calculated. Additionally, the arterial vessel diameters were measured. Pre- and post-interventional values were compared and tested for significance, respectively. Flow analysis revealed in all arterial vessel segments a non-statistically significant prolongation of rTmax after treatment. The mean CirT was 5.62 s (+/- 1.19 s) pre-interventionally and 5.16 s (+/- 0.81 s) post-interventionally, and the difference turned out as statistically significant (p = 0.039). A significantly increased diameter was measurable in all arterial segments post-interventionally. PCC is a fast applicable imaging technique that allows via real-time and in vivo blood flow analysis a quantitative assessment of the effect of intra-arterial vasospasm therapy. Our results seem to validate in vivo that an intra-arterial nimodipine application induces not only vasodilatation of the larger vessels, but also improves the microcirculatory flow, leading to a shortened cerebral CirT that reaches normal range post-interventionally. Procedural monitoring via PCC offers the option to compare quantitatively different therapy regimes, which allows optimization of existing approaches and implementation of individualized treatment strategies.

关键词： Vascular disease Subarachnoidal hemorrhage Cerebral vasospasm Endovascular treatment image postprocessing

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