1,857 results match your criteria abdominal projection


Abdominal synthetic CT reconstruction with intensity projection prior for MRI-only adaptive radiotherapy.

Phys Med Biol 2021 Sep 16. Epub 2021 Sep 16.

Medical Artificial Intelligence and Automation (MAIA) Laboratory, Department of Radiation Oncology, The University of Texas Southwestern Medical Center, Dallas, Texas, UNITED STATES.

Objective: Owing to the superior soft tissue contrast of MRI, MRI-guided adaptive radiotherapy (ART) is well-suited to managing interfractional changes in anatomy. An MRI-only workflow is desirable, but producing synthetic CT (sCT) data through paired data-driven deep learning (DL) for abdominal dose calculations remains a challenge due to the highly variable presence of intestinal gas. We present the preliminary dosimetric evaluation of our novel approach to sCT reconstruction that is well suited to handling intestinal gas in abdominal MRI-only ART. Read More

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September 2021

A Huygens' surface approach to rapid characterization of peripheral nerve stimulation.

Magn Reson Med 2021 Aug 24. Epub 2021 Aug 24.

A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA.

Purpose: Peripheral nerve stimulation (PNS) modeling has a potential role in designing and operating MRI gradient coils but requires computationally demanding simulations of electromagnetic fields and neural responses. We demonstrate compression of an electromagnetic and neurodynamic model into a single versatile PNS matrix (P-matrix) defined on an intermediary Huygens' surface to allow fast PNS characterization of arbitrary coil geometries and body positions.

Methods: The Huygens' surface approach divides PNS prediction into an extensive pre-computation phase of the electromagnetic and neurodynamic responses, which is independent of coil geometry and patient position, and a fast coil-specific linear projection step connecting this information to a specific coil geometry. Read More

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Comparison of two versions of a deep learning image reconstruction algorithm on CT image quality and dose reduction: A phantom study.

Med Phys 2021 Aug 21. Epub 2021 Aug 21.

Department of medical imaging, CHU Nîmes, Nîmes Medical Imaging Group, Univ Montpellier, Nîmes, France.

Purpose: To compare the impact on CT image quality and dose reduction of two versions of a Deep Learning Image Reconstruction algorithm.

Material And Methods: Acquisitions on the CT ACR 464 phantom were performed at five dose levels (CTDI : 10/7.5/5/2. Read More

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Deep learning enabled ultra-fast-pitch acquisition in clinical X-ray computed tomography.

Med Phys 2021 Aug 20. Epub 2021 Aug 20.

Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.

Objective: In X-raycomputed tomography (CT), many important clinical applications may benefit from a fast acquisition speed. The helical scan is the most widely used acquisition mode in clinical CT, where a fast helical pitch can improve the acquisition speed. However, on a typical single-source helical CT (SSCT) system, the helical pitch p typically cannot exceed 1. Read More

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Maximum intensity projection aids in diagnosing acute appendicitis and mobile caecum: A case report and literature review.

SA J Radiol 2021 28;25(1):2153. Epub 2021 Jul 28.

Department of Surgery, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa.

Appendicitis is a common childhood condition requiring surgical intervention and delayed diagnosis can have serious consequences. This report describes the case of a child who presented with an acute abdomen and intestinal obstruction. Multidetector (MD) CT demonstrated a left-sided caecum and an inflamed appendix with a faecolith. Read More

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Accuracy of third trimester ultrasound in predicting neonatal birthweight in patients with inflammatory bowel disease.

Eur J Obstet Gynecol Reprod Biol 2021 Sep 31;264:336-339. Epub 2021 Jul 31.

Department of Obstetrics, Gynecology and Reproductive Science, Icahn School of Medicine at Mount Sinai, New York, NY, USA.

Objective: To evaluate the accuracy of third trimester ultrasound in predicting birthweight in patients with inflammatory bowel disease (IBD) using the gestation-adjusted projection (GAP) method.

Study Design: Retrospective cohort study including pregnant patients with IBD who had third trimester ultrasounds and delivered at a single institution from 2012 to 2017. Controls included pregnant patients without IBD seen during the study period with third trimester ultrasounds. Read More

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September 2021

Diagnostic performance and image quality of deep learning image reconstruction (DLIR) on unenhanced low-dose abdominal CT for urolithiasis.

Acta Radiol 2021 Aug 9:2841851211035896. Epub 2021 Aug 9.

Department of Radiology, Amiens University Hospital, Amiens Cedex, France.

Background: Patients with urolithiasis undergo radiation overexposure from computed tomography (CT) scans. Improvement of image reconstruction is necessary for radiation dose reduction.

Purpose: To evaluate a deep learning-based reconstruction algorithm for CT (DLIR) in the detection of urolithiasis at low-dose non-enhanced abdominopelvic CT. Read More

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Low monoenergetic DECT detection of pyelonephritis extent.

Eur J Radiol 2021 Sep 8;142:109837. Epub 2021 Jul 8.

Department of Radiology, Hadassah Medical Center, Hebrew University of Jerusalem, The Faculty of Medicine, Jerusalem 91120, Israel. Electronic address:

Objectives: To determine whether contrast enhanced DECT low monoenergetic can improve diagnostic conspicuity of inflamed kidney foci in acute pyelonephritis compared to conventional images.

Materials And Methods: A retrospective study of 45 patients with clinical signs of acute pyelonephritis undergoing contrast-enhanced exams on a single source-DECT was conducted. Representative conventional and monoenergetic images were randomized and presented to four abdominal radiologists to determine their preference for inflamed kidney foci detection, and to determine the number of foci identified. Read More

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September 2021

The utility of free abdominal flap without Zone 4 procedure for unilateral breast reconstruction.

Microsurgery 2021 Jul 31. Epub 2021 Jul 31.

Department of Plastic, Reconstructive and Aesthetic Surgery, Chiba University, Faculty of Medicine, Chiba City, Chiba, Japan.

Background: The perfusion concept of free abdominal flap for breast reconstruction shares the common perception. We believed that free abdominal flap without Zone 4 could be performed. The purpose of this study is to introduce the "without Zone 4 procedure" and compare with the conventional technique (without 4 vs. Read More

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Evaluating Size-Specific Dose Estimate (SSDE) as an estimate of organ doses from routine CT exams derived from Monte Carlo simulations.

Med Phys 2021 Jul 26. Epub 2021 Jul 26.

Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, Livermore, USA.

Purpose: Size-specific dose estimate (SSDE) is a metric that adjusts CTDI to account for patient size. While not intended to be an estimate of organ dose, AAPM Report 204 notes the difference between the patient organ dose and SSDE is expected to be 10-20%. The purpose of this work was therefore to evaluate SSDE against estimates of organ dose obtained using Monte Carlo (MC) simulation techniques applied to routine exams across a wide range of patient sizes. Read More

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Feasibility of anterior pedicle screw fixation in lumbosacral spine: a radiographic and cadaveric study.

Ann Transl Med 2021 Jun;9(12):968

Department of Orthopaedics, Tongde Hospital of Zhejiang Province, Hangzhou, China.

Background: The anterior pedicle screw (APS) technique for L5 and S1 is crucial for proper anterior lumbar interbody fusion (ALIF). This study aimed to determine the projection, screw trajectory angle, and bone screw passageway length (BSPL), as well as the screw insertion regularity and the operating area within which it is safe to perform insertion.

Methods: Forty patients with low back pain, all of whom had lumbar computed tomography scans available, was included in this retrospective analysis. Read More

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Sparse-sampling computed tomography for detection of endoleak after endovascular aortic repair (EVAR).

Eur J Radiol 2021 Sep 9;142:109843. Epub 2021 Jul 9.

Klinikum rechts der Isar, School of Medicine Technical University of Munich, Institute of Diagnostic and Interventional Radiology, Munich, Germany.

Objectives: To evaluate sparse sampling computed tomography (SpSCT) for detection of endoleak after endovascular aortic repair (EVAR) at different dose levels in terms of subjective image criteria and diagnostic accuracy.

Methods: Twenty clinically indicated computed tomography aortic angiography (CTA) scans were used to obtain simulated low-dose scans with 100%, 50%, 25%, 12.5% and 6. Read More

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September 2021

Expression pattern of CAPA/pyrokinin neuropeptide genes in Remipedia and silverfish: Rapid differentiation after gene duplication in early Hexapoda, followed by strong conservation of newly established features in insects.

Peptides 2021 Oct 7;144:170610. Epub 2021 Jul 7.

Department of Biology, Institute of Zoology, University of Cologne, D-50674, Cologne, Germany. Electronic address:

Only few genes are known from insects that encode multiple neuropeptides, i.e., peptides that activate different receptors. Read More

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October 2021

Reduction of streak artifacts caused by low photon counts utilizing an image-based forward projection in computed tomography.

Comput Biol Med 2021 08 26;135:104583. Epub 2021 Jun 26.

Radiology Division, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, 920-8641, Japan. Electronic address:

Background: The streak artifacts in computed tomography (CT) images caused by low photon counts are known to be effectively suppressed by raw-data-based techniques. This study aims to propose a technique to reduce the streak artifact without accessing the raw data.

Methods: The proposed streak artifact reduction (SAR) technique consists of three steps: numerical forward projection to a CT image, adaptive filtering of the generated sinogram, and image reconstruction from the processed sinogram. Read More

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Consensus guidelines on the role of cholangioscopy to diagnose indeterminate biliary stricture.

HPB (Oxford) 2021 Jun 9. Epub 2021 Jun 9.

Division of Gastroenterology, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand; Center of Excellence for Innovation and Endoscopy in Gastrointestinal Oncology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. Electronic address:

Background: Indeterminate strictures pose a therapeutic dilemma. In recent years, cholangioscopy has evolved and the availability of cholangioscopy has increased. However, the position of cholangioscopy in the diagnostic algorithm to diagnose malignancy have not been well established. Read More

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Image quality improvement with deep learning-based reconstruction on abdominal ultrahigh-resolution CT: A phantom study.

J Appl Clin Med Phys 2021 Jul 23;22(7):286-296. Epub 2021 Jun 23.

Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

Purpose: In an ultrahigh-resolution CT (U-HRCT), deep learning-based reconstruction (DLR) is expected to drastically reduce image noise without degrading spatial resolution. We assessed a new algorithm's effect on image quality at different radiation doses assuming an abdominal CT protocol.

Methods: For the normal-sized abdominal models, a Catphan 600 was scanned by U-HRCT with 100%, 50%, and 25% radiation doses. Read More

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A methodology to estimate the patient diameter and thickness from thoracic and abdominal projection radiographs of adult patients.

Phys Med Biol 2021 Jul 7;66(14). Epub 2021 Jul 7.

Department of Imaging and Pathology, Division of Medical Physics and Quality Assessment, University of Leuven, Leuven, B-3000, Belgium.

Patient dose management systems can be part of a department's quality management tools to estimate items such as the radiation burden in specific groups or list dose outliers for further follow up. Patient size information could improve both aspects, but is not generally available. A new metric is proposed to estimate patient size for thorax and abdominal projection radiography from parameters available in thedicomheader and therefore accessible by dose management software. Read More

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Effect of deep learning image reconstruction in the prediction of resectability of pancreatic cancer: Diagnostic performance and reader confidence.

Eur J Radiol 2021 Aug 11;141:109825. Epub 2021 Jun 11.

Department of Radiology, Duke University Medical Center, Durham, NC, USA.

Objective: To assess the diagnostic performance and reader confidence in determining the resectability of pancreatic cancer at computed tomography (CT) using a new deep learning image reconstruction (DLIR) algorithm.

Methods: A retrospective review was conduct of on forty-seven patients with pathologically confirmed pancreatic cancers who underwent baseline multiphasic contrast-enhanced CT scan. Image data sets were reconstructed using filtered back projection (FBP), hybrid model-based adaptive statistical iterative reconstruction (ASiR-V) 60 %, and DLIR "TrueFidelity" at low(L), medium(M), and high strength levels(H). Read More

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Superior objective and subjective image quality of deep learning reconstruction for low-dose abdominal CT imaging in comparison with model-based iterative reconstruction and filtered back projection.

Br J Radiol 2021 Jul;94(1123):20201357

Department of Radiology, Iwate Medical University School of Medicine, Iwate, Japan.

Objective: This study aimed to conduct objective and subjective comparisons of image quality among abdominal computed tomography (CT) reconstructions with deep learning reconstruction (DLR) algorithms, model-based iterative reconstruction (MBIR), and filtered back projection (FBP).

Methods: Datasets from consecutive patients who underwent low-dose liver CT were retrospectively identified. Images were reconstructed using DLR, MBIR, and FBP. Read More

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Forecast modeling to identify changes in pediatric emergency department utilization during the COVID-19 pandemic.

Am J Emerg Med 2021 May 21;49:142-147. Epub 2021 May 21.

Division of Pediatric Critical Care Medicine, Department of Critical Care Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, United States of America; Division of Health Informatics, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, United States of America.

Objective: To identify trends in pediatric emergency department (ED) utilization following the COVID-19 pandemic.

Methods: We performed a cross-sectional study from 37 geographically diverse US children's hospitals. We included ED encounters between January 1, 2010 and December 31, 2020, transformed into time-series data. Read More

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The potential for reduced radiation dose from deep learning-based CT image reconstruction: A comparison with filtered back projection and hybrid iterative reconstruction using a phantom.

Medicine (Baltimore) 2021 May;100(19):e25814

Department of Radiology, Soonchunhyang University College of Medicine, Bucheon Hospital, Bucheon.

Abstract: The purpose of this phantom study is to compare radiation dose and image quality of abdominal computed tomography (CT) scanned with different tube voltages and tube currents, reconstructed with filtered back projection (FBP), hybrid iterative reconstruction (IR) and deep learning image reconstruction (DLIR) algorithms.A total of 15 CT scans of whole body phantoms were taken with 3 different tube voltages and 5 different tube currents. The images were reconstructed with FBP, 30% and 50% hybrid IR adaptive statistical iterative reconstruction (ASIR-V), and low, medium and high strength DLIR algorithms. Read More

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A preliminary evaluation study of applying a deep learning image reconstruction algorithm in low-kilovolt scanning of upper abdomen.

J Xray Sci Technol 2021 ;29(4):687-695

GE Company, Beijing, China.

Objective: To investigate feasibility of applying deep learning image reconstruction (DLIR) algorithm in a low-kilovolt enhanced scan of the upper abdomen.

Methods: A total of 64 patients (BMI<28) are selected for the enhanced upper abdomen scan and divided evenly into two groups. The tube voltages in Group A are 100kV in arterial phase and 80kV in venous phase, while tube voltages are 120kV during two phases in Group B. Read More

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January 2021

Influence of Adaptive Statistical Iterative Reconstructions on CT Radiomic Features in Oncologic Patients.

Diagnostics (Basel) 2021 May 31;11(6). Epub 2021 May 31.

Radiology Unit, Department of Medical Surgical Sciences and Translational Medicine, Sapienza University of Rome, Sant'Andrea University Hospital, Via di Grottarossa, 1035-1039, 00189 Rome, Italy.

Iterative reconstructions (IR) might alter radiomic features extraction. We aim to evaluate the influence of Adaptive Statistical Iterative Reconstruction-V (ASIR-V) on CT radiomic features. Patients who underwent unenhanced abdominal CT (Revolution Evo, GE Healthcare, USA) were retrospectively enrolled. Read More

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Aortic dissection diagnosed on stroke computed tomography protocol: a case report.

J Med Case Rep 2021 May 26;15(1):299. Epub 2021 May 26.

Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.

Background: Aortic dissection is one of the causes of stroke. Because cerebral infarction with aortic dissection is a contraindication to intravenous recombinant tissue plasminogen activator (rt-PA) therapy, exclusion of aortic dissection is necessary prior to its administration. However, imaging takes time to provide a diagnosis, possibly causing delays in surgical treatment. Read More

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Multimaterial decomposition algorithm for quantification of fat in hepatocellular carcinoma using rapid kilovoltage-switching dual-energy CT: A comparison with chemical-shift MR imaging.

Medicine (Baltimore) 2021 May;100(20):e26109

Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine.

Abstract: Understanding intratumoral fat in hepatocellular carcinoma (HCC) is clinically important to elucidate prognosis. We sought to quantify HCC and liver fat with a multimaterial decomposition (MMD) algorithm with rapid kilovoltage-switching dual-energy computed tomography (DECT) relative to chemical-shift magnetic resonance imaging (CSI).In this retrospective study, 40 consecutive patients with HCC underwent non-contrast-enhanced (non-CE) and four-phases contrast-enhanced (four-CE) DECT (80 and 140 kVp) and abdominal MR imaging (including CSI) between April 2011 and December 2012. Read More

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Dual energy CT in acute appendicitis: value of low mono-energy.

Clin Imaging 2021 Sep 20;77:213-218. Epub 2021 Apr 20.

Department of Radiology, Hadassah Medical Center, Hebrew University of Jerusalem, The Faculty of Medicine, Jerusalem 91120, Israel.

Objectives: To assess the potential role of low monoenergetic images in the evaluation of acute appendicitis.

Methods: A retrospective study of 42 patients with pathology proven acute appendicitis underwent contrast-enhanced-CT conducted on a single-source-DECT before surgery. Attenuation, SNR, and CNR were calculated on both monoenergetic and conventional images and compared to 24 abdominal CT-scans with normal appendix. Read More

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September 2021

A comparison of breast and lung doses from chest CT scans using organ-based tube current modulation (OBTCM) vs. Automatic tube current modulation (ATCM).

J Appl Clin Med Phys 2021 May 3;22(5):97-109. Epub 2021 May 3.

Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.

Purpose: The purpose of this work was to estimate and compare breast and lung doses of chest CT scans using organ-based tube current modulation (OBTCM) to those from conventional, attenuation-based automatic tube current modulation (ATCM) across a range of patient sizes.

Methods: Thirty-four patients (17 females, 17 males) who underwent clinically indicated CT chest/abdomen/pelvis (CAP) examinations employing OBTCM were collected from two multi-detector row CT scanners. Patient size metric was assessed as water equivalent diameter (D ) taken at the center of the scan volume. Read More

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Simultaneous hepatic iron and fat quantification with dual-energy CT in a rabbit model of coexisting iron and fat.

Quant Imaging Med Surg 2021 May;11(5):2001-2012

Department of Radiology, Northern Jiangsu People's Hospital, Clinical Medical College, Yangzhou University, Yangzhou, China.

Background: Liver iron and fat are often co-deposited, synergistically aggravating the progression of chronic liver disease. Accurate determination of liver iron and fat content is helpful for patient management. To assess the accuracy of hepatic iron/fat decomposition using dual-energy computed tomography (DECT) for simultaneously quantifying hepatic iron and fat when both are present. Read More

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Comparison of image quality and lesion diagnosis in abdominopelvic unenhanced CT between reduced-dose CT using deep learning post-processing and standard-dose CT using iterative reconstruction: A prospective study.

Eur J Radiol 2021 Jun 24;139:109735. Epub 2021 Apr 24.

From the Department of Radiology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China. Electronic address:

Purpose: To compare image quality and lesion diagnosis between reduced-dose abdominopelvic unenhanced computed tomography (CT) using deep learning (DL) post-processing and standard-dose CT using iterative reconstruction (IR).

Method: Totally 251 patients underwent two consecutive abdominopelvic unenhanced CT scans of the same range, including standard and reduced doses, respectively. In group A, standard-dose data were reconstructed by (blend 30 %) IR. Read More

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An algorithm for automatically generating gas, bone and foreign body visualizations from postmortem computed tomography data.

Forensic Sci Med Pathol 2021 Jun 27;17(2):254-261. Epub 2021 Apr 27.

3D Center Zurich, Institute of Forensic Medicine Zurich, University of Zurich, Winterthurerstrasse 190/52 CH-8052, Zurich, Switzerland.

Post mortem computed tomography (PMCT) can aid in localizing foreign bodies, bone fractures, and gas accumulations. The visualization of these findings play an important role in the communication of radiological findings. In this article, we present an algorithm for automated visualization of gas distributions on PMCT image data of the thorax and abdomen. Read More

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