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Hounsfield Units (HU)

Wookjin Choi, Ming Xue, Barton F Lane, Min Kyu Kang, Kruti Patel, William F Regine, Paul Klahr, Jiahui Wang, Shifeng Chen, Warren D'Souza, Wei Lu
PURPOSE: To develop an individually optimized contrast-enhanced (CE) 4D-computed tomography (CT) for radiotherapy simulation in pancreatic ductal adenocarcinomas (PDA). METHODS: Ten PDA patients were enrolled. Each underwent three CT scans: a 4D-CT immediately following a CE 3D-CT and an individually optimized CE 4D-CT using test injection. Three physicians contoured the tumor and pancreatic tissues. Image quality scores, tumor volume, motion, tumor-to-pancreas contrast, and contrast-to-noise ratio (CNR) were compared in the three CTs...
October 2016: Medical Physics
Peter M Formby, Daniel G Kang, Melvin D Helgeson, Scott C Wagner
Study Design Retrospective review. Objective To compare clinical outcomes after transforaminal lumbar interbody fusion (TLIF) in patients with and patients without osteoporosis. Methods We reviewed all patients with 6-month postoperative radiographs and computed tomography (CT) scans for evaluation of the interbody cage. CT Hounsfield unit (HU) measurements of the instrumented vertebral body were used to determine whether patients had osteoporosis. Radiographs and CT scans were evaluated for evidence of implant subsidence, migration, interbody fusion, iatrogenic fracture, or loosening of posterior pedicle screw fixation...
November 2016: Global Spine Journal
Atsushi Nambu, Jordan Zach, Joyce Schroeder, Gongyoung Jin, Song Soo Kim, Yu-Il Kim, Christina Schnell, Russell Bowler, David A Lynch
PURPOSE: To correlate currently available quantitative CT measurements for airway disease with physiological indices and the body-mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index in patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: This study was approved by our institutional review board (IRB number 2778). Written informed consent was obtained from all subjects. The subjects included 188 current and former cigarette smokers from the COPDGene cohort who underwent inspiratory and expiratory CT and also had physiological measurements for the evaluation of airflow limitation, including FEF25-75%, airway resistance (Raw), and specific airway conductance (sGaw)...
November 2016: European Journal of Radiology
Yuichi Nishiyama, Hidekazu Kanayama, Hiroshi Mori, Keiji Tada, Yasushi Yamamoto, Takashi Katsube, Haruo Takeshita, Kazunori Kawakami, Hajime Kitagaki
OBJECTIVES: This study examined the usefulness of statistical parametric mapping (SPM) for investigating postmortem changes on brain computed tomography (CT). METHODS: This retrospective study included 128 patients (23 - 100 years old) without cerebral abnormalities who underwent unenhanced brain CT before and after death. The antemortem CT (AMCT) scans and postmortem CT (PMCT) scans were spatially normalized using our original brain CT template, and postmortem changes of CT values (in Hounsfield units; HU) were analysed by the SPM technique...
October 21, 2016: European Radiology
Ravi K Kaza, Evan A Raff, Matthew S Davenport, Shokoufeh Khalatbari
RATIONALE AND OBJECTIVES: To compare Hounsfield unit (HU) data obtained from true-unenhanced (TUE) and virtual-unenhanced (VUE) imaging obtained with a fast kv-switching dual-energy computed tomography (CT) scanner using multimaterial decomposition algorithm. MATERIALS AND METHODS: In this Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant, retrospective cohort study, CT scans of 19 patients undergoing multiphasic renal protocol abdominal CT on a fast kv-switching dual-energy CT scanner were reviewed...
October 18, 2016: Academic Radiology
Daniel Schober, Nicole Schwendener, Wolf-Dieter Zech, Christian Jackowski
Segmentation of the lungs using post-mortem computed tomography (PMCT) data was so far not feasible due to post-mortem changes such as internal livores. Recently, an Osirix plug-in has been developed allowing automatically segmenting lungs also in PMCT data. The aim of this study was to investigate if the Hounsfield unit (HU) profiles obtained in PMCT data of the segmented lung tissue present with specific behaviour in relation to the cause of death. In 105 PMCT data sets of forensic cases, the entire lung volumes were segmented using the Mia Lite plug-in on Osirix...
October 20, 2016: International Journal of Legal Medicine
Takayoshi Yamaguchi, Katsuhiro Ichikawa, Daichi Takahashi, Teppei Sugaya, Jungo Furuya, Keiichi Igarashi
RATIONALE AND OBJECTIVES: We have developed a new contrast enhancement protocol for subtraction coronary computed tomography (SCCTA) requiring a short breath-holding time. In the protocol, test and main boluses were sequentially and automatically injected, and correct timings for pre-contrast and contrast-enhanced scans for main bolus were automatically determined only by the test bolus tracking. Combined with a fixed short main bolus injection for 7 seconds, the breath-holding time was shortened as possible...
October 17, 2016: Academic Radiology
Hillary W Garner, Michelle M Paturzo, Gabriela Gaudier, Perry J Pickhardt, Daniel E Wessell
OBJECTIVE: The purpose of this study is to investigate the variation in attenuation values (expressed as Hounsfield units) for L1 vertebral body trabecular bone at different tube voltages used in dual-energy CT (DECT) and to remind physicians to consider changes in attenuation values when they approach opportunistic screening for osteoporosis. MATERIAL AND METHODS: Consecutive patients who underwent DECT examination of the abdomen and pelvis for suspected urolithiasis were included in the study...
October 20, 2016: AJR. American Journal of Roentgenology
Yasheng Chen, Rajat Dhar, Laura Heitsch, Andria Ford, Israel Fernandez-Cadenas, Caty Carrera, Joan Montaner, Weili Lin, Dinggang Shen, Hongyu An, Jin-Moo Lee
Although cerebral edema is a major cause of death and deterioration following hemispheric stroke, there remains no validated biomarker that captures the full spectrum of this critical complication. We recently demonstrated that reduction in intracranial cerebrospinal fluid (CSF) volume (∆ CSF) on serial computed tomography (CT) scans provides an accurate measure of cerebral edema severity, which may aid in early triaging of stroke patients for craniectomy. However, application of such a volumetric approach would be too cumbersome to perform manually on serial scans in a real-world setting...
2016: NeuroImage: Clinical
Yoriaki Matsumoto, Takanori Masuda, Yukari Yamashita, Takayuki Oku, Hirofumi Uyama, Tomoyasu Sato, Naoyuki Imada
PURPOSE: The purpose of this study was to investigate the association of vessel visibility and radiation dose using contrast-to-noise ratio (CNR) method with low tube voltage in coronary computed tomography angiography (c-CTA). METHODS: We performed electrocardiogram-gated scan of 2.0-mm diameter simulated vessel in the center of the cardiac phantom by the use of a 64-detector CT scanner. Reference CNR was calculated from the target coronary CT number (CTnumberA; 350 Hounsfield units [HU]), epicardial fat CT number (CTnumberB; -100 HU), and target epicardial fat standard deviation (SD) number (SDB; 25 HU) at the 120 kV...
2016: Nihon Hoshasen Gijutsu Gakkai Zasshi
Karin Slebocki, Bastian Kraus, De-Hua Chang, Martin Hellmich, David Maintz, Christopher Bangard
PURPOSE: To assess correlation between attenuation measurements of incidental findings in abdominal second generation dual-energy computed tomography (CT) on true noncontrast (TNC) and virtual noncontrast (VNC) images. MATERIALS AND METHODS: Sixty-three patients underwent arterial dual-energy CT (Somatom Definition Flash, Siemens; pitch factor, 0.75-1.0; gantry rotation time, 0.28 seconds) after endovascular aneurysm repair, consisting of a TNC single energy CT scan (collimation, 128 × 0...
October 18, 2016: Journal of Computer Assisted Tomography
Girish Dwivedi, Yingwei Liu, Shrankhala Tewari, Joao Inacio, Matthieu Pelletier-Galarneau, Benjamin J W Chow
BACKGROUND: Coronary computed tomography (CT) angiography (CCTA) has the ability to detect, characterize, and quantify atherosclerotic plaques. The aim of our study was to evaluate the prognostic power of CCTA-quantified plaque subtypes. MATERIALS AND METHODS: A total of 36 patients with adverse events and 36 Morise score-matched patients who remained event free on follow-up were identified. Using CCTA images, plaque subtype volumes in the major epicardial arteries were analyzed using predetermined attenuation ranges in Hounsfield units (HU): 1 to 30 HU (low attenuating), 31 to 70 HU (intermediate attenuating), 71 to 150 HU (high attenuating), and mean coronary lumen+2 SD to 1000 HU (calcified)...
November 2016: Journal of Thoracic Imaging
Jason A Fuerst, Jean K Reichle, David Szabo, Eli B Cohen, David S Biller, Justin M Goggin, John F Griffin, Stacie Aarsvold, Susan E Emerson
Computed tomography (CT) continues to become more widely available for assessment of tumors in dogs, yet there are no studies describing the CT appearance of canine liposarcomas. In this retrospective, multicenter study, CT images of dogs with histologically confirmed liposarcomas were reviewed for size, location, attenuation, contrast enhancement, border definition, internal homogeneity, local infiltration, and mineralization. A total of 24 dogs with 26 liposarcomas were sampled. Mean attenuation was +15.2 (SD = 22...
October 17, 2016: Veterinary Radiology & Ultrasound
Kevin P Murphy, Patrick D McLaughlin, Maria Twomey, Vincent E Chan, Fiachra Moloney, Adrian J Fung, Faimee E Chan, Tafline Kao, Siobhan B O'Neill, Benjamin Watson, Owen J O'Connor, Michael M Maher
INTRODUCTION: We assess the ability of low-dose hybrid iterative reconstruction (IR) and 'pure' model-based IR (MBIR) images to maintain accurate Hounsfield unit (HU)-determined tissue characterization. METHODS: Standard-protocol (SP) and low-dose modified-protocol (MP) CTs were contemporaneously acquired in 34 Crohn's disease patients referred for CT. SP image reconstruction was via the manufacturer's recommendations (60% FBP, filtered back projection; 40% ASiR, Adaptive Statistical iterative Reconstruction; SP-ASiR40)...
October 13, 2016: Journal of Medical Imaging and Radiation Oncology
Pernille Svendsen, Nitesh Shekhrajka, Kasper Lindblad Nielsen, Peter Vestergaard, Mette Østergaard Poulsen, Anders Krog Vistisen, Peter Svenssen Munksgaard, Marianne Tang Severinsen, Paw Jensen, Hans Erik Johnsen, Lasse Hjort Jakobsen, Martin Bøgsted, Jens Brøndum Frøkjær, Tarec Christoffer El-Galaly
Treatment of diffuse large B-cell lymphoma (DLBCL) with R-CHOP(-like) regimens include large cumulative doses of prednisolone. In this retrospective study, we evaluated changes in vertebral bone density (VD) in DLBCL patients by measuring CT-ascertained Hounsfield units (HU) at the L3 level. In total, 111 patients diagnosed from 2007 to 2012 and response assessed following first line treatment were included. Post-treatment VD was significantly reduced to 86% of pretreatment VD on average (p < .001). Neither female sex nor high age (>70 years) were significantly associated with greater post-treatment VD reduction...
October 13, 2016: Leukemia & Lymphoma
Janan Abbas, Viviane Slon, Hila May, Nathan Peled, Israel Hershkovitz, Kamal Hamoud
BACKGROUND: The condition of paraspinal muscles is known to be associated with some variables such as age, gender, and low back pain. It is generally agreed that these muscles play an important role in the stability and functional movements of the lumbar vertebral column. Although spinal instability has been shown to play an essential role in degenerative lumbar spinal stenosis (DLSS), the role of paraspinal muscles remains elusive. The main purpose of this study was to shed light on the relationship between the condition of paraspinal muscles and symptomatic DLSS...
October 10, 2016: BMC Musculoskeletal Disorders
Hideki Katagiri, Alan Kawarai Lefor, Tadao Kubota, Ken Mizokami
AIM: To review clinical experience with barium appendicitis at a single institution. METHODS: A retrospective review of patients admitted with a diagnosis of acute appendicitis, from January 1, 2013 to December 31, 2015 was performed. Age, gender, computed tomography (CT) scan findings if available, past history of barium studies, pathology, and the presence of perforation or the development of complications were reviewed. If the CT scan revealed high density material in the appendix, the maximum CT scan radiodensity of the material is measured in Hounsfield units (HU)...
September 27, 2016: World Journal of Gastrointestinal Surgery
A Villamonte-Chevalier, W Dingemanse, B J G Broeckx, A Van Caelenberg, A Agut, L Duchateau, H van Bree, I Gielen
The aims of this study were: (1) to determine the inter-observer repeatability of particular regions of the canine elbow joints; (2) to assess the effect of age, bodyweight and breed on bone density in healthy young dogs; (3) to compare Hounsfield units (HU) and bone density (BD) measurements between normal elbow joints and diseased elbow joints; and (4) to determine the sensitivity and specificity for HU and BD measurements in specific regions in the canine elbow joint. Regions with the highest repeatability were located at the medial coronoid process (MCP) base and apex, and at the level of the humerus, on the sagittal and sagittal oblique planes of the elbow joint...
October 2016: Veterinary Journal
Jane J Lee, Alison Pedley, Udo Hoffmann, Joseph M Massaro, Caroline S Fox
BACKGROUND: Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) are associated with adverse cardiometabolic risk profiles. OBJECTIVES: This study explored the degree to which changes in abdominal fat quantity and quality are associated with changes in cardiovascular disease (CVD) risk factors. METHODS: Study participants (n = 1,106; 44.1% women; mean baseline age 45.1 years) were drawn from the Framingham Heart Study Third Generation cohort who participated in the computed tomography (CT) substudy Exams 1 and 2...
October 4, 2016: Journal of the American College of Cardiology
Dete van Eeden, Freek du Plessis
INTRODUCTION: A mathematical 3D model of an existing computed tomography (CT) scanner was created and used in the EGSnrc-based BEAMnrc and egs_cbct Monte Carlo codes. Simulated transmission dose profiles of a RMI-465 phantom were analysed to verify Hounsfield numbers against measured data obtained from the CT scanner. METHODS AND MATERIALS: The modelled CT unit is based on the design of a Toshiba Aquilion 16 LB CT scanner. As a first step, BEAMnrc simulated the X-ray tube, filters, and secondary collimation to obtain phase space data of the X-ray beam...
September 24, 2016: Physica Medica: PM
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