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Hounsfield Units (HU)

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https://www.readbyqxmd.com/read/29153933/computed-tomographic-window-setting-for-bronchial-measurement-to-guide-double-lumen-tube-size
#1
Jeong-Hwa Seo, Jinyoung Bae, Hyesun Paik, Chang-Hoon Koo, Jae-Hyon Bahk
OBJECTIVES: The bronchial diameter measured on computed tomography (CT) can be used to guide double-lumen tube (DLT) sizes objectively. The bronchus is known to be measured most accurately in the so-called bronchial CT window. The authors investigated whether using the bronchial window results in the selection of more appropriately sized DLTs than using the other windows. DESIGN: CT image analysis and prospective randomized study. SETTING: Tertiary hospital...
October 5, 2017: Journal of Cardiothoracic and Vascular Anesthesia
https://www.readbyqxmd.com/read/29142632/delayed-burr-hole-surgery-in-patients-with-acute-subdural-hematoma-clinical-analysis
#2
Yoon Heuck Choi, Seong Rok Han, Chang Hyun Lee, Chan Young Choi, Moon Jun Sohn, Chae Heuck Lee
Objective: To evaluate the effectiveness and efficacy of delayed burr hole surgery in relation to the reduction of postoperative subdural hematoma (SDH) volume in patients with acute SDH. Methods: We retrospectively analyzed patients with acute SDH who received delayed burr hole surgery at our institute. Age, sex, Glasgow coma scale, maximal SDH thickness, volume of SDH, midline shifts, hounsfield unit (HU), and medical history of anticoagulant agent usage were recorded...
November 2017: Journal of Korean Neurosurgical Society
https://www.readbyqxmd.com/read/29138890/role-of-rapid-kv-switching-dual-energy-ct-in-assessment-of-post-surgical-local-recurrence-of-pancreatic-adenocarcinoma
#3
Anushri Parakh, Manuel Patino, Daniela Muenzel, Avinash Kambadakone, Dushyant V Sahani
PURPOSE: The purpose of this study is to evaluate the performance of material-specific iodine (MS-I) images generated by rapid kV-switching single-source dual-energy computed tomography (rsDECT) for distinguishing post-operative changes from local tumor recurrence in patients on follow-up for pancreatic adenocarcinoma after surgical resection. METHODS: In this IRB-approved HIPPA-compliant study, retrospective review of 51 patients who underwent surgical resection of pancreatic adenocarcinoma was conducted and were followed up using contrast-enhanced rsDECT (Discovery CT 750HD, GE Healthcare, Milwaukee, WI)...
November 14, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/29134241/ct-based-evaluation-of-volumetric-bone-density-in-fragility-fractures-of-the-pelvis-a-matched-case-control-analysis
#4
D Schönenberg, R Guggenberger, D Frey, H-C Pape, H-P Simmen, G Osterhoff
This matched case-control study compared the computed tomography (CT)-based regional bone density of patients with fragility fractures of the sacrum to a control without fracture. Patients with a sacral fracture demonstrated a significantly lower regional bone density of the sacrum, the sacral bone density not being correlated with the BMD by DXA of the spine. INTRODUCTION: The aim of this study is to compare the computed tomography-based regional bone density measured by Hounsfield units (HUs) in patients with and without fragility fractures of the sacrum...
November 13, 2017: Osteoporosis International
https://www.readbyqxmd.com/read/29128112/predicting-pathological-fracture-in-femoral-metastases-using-a-clinical-ct-scan-based-algorithm-a-case-control-study
#5
Stein J Janssen, Nuno Rui Paulino Pereira, Timion A Meijs, Miriam A Bredella, Marco L Ferrone, C Niek van Dijk, Jos A M Bramer, Santiago A Lozano-Calderón, Joseph H Schwab
BACKGROUND: We assessed whether there was a difference in attenuation measurements (in Hounsfield units - HU) and geometric distribution of HU between femora with metastatic lesions that fracture, and metastatic lesions that did not fracture nor underwent prophylactic fixation. METHODS: Nine patients with femoral metastases who underwent CT and developed a pathological fracture were matched to controls. All femora were delineated in axial CT slices using a region of interest (ROI) tool; the HU within these ROIs were used to calculate: (1) the cumulative HU of the affected over the nonaffected side per slice and presented as a percentage, and (2) the cumulative HU accounting for geometric distribution (polar moment of HU)...
November 8, 2017: Journal of Orthopaedic Science: Official Journal of the Japanese Orthopaedic Association
https://www.readbyqxmd.com/read/29123859/non-traumatic-bladder-rupture-showing-less-than-10-hounsfield-units-of-ascites
#6
Naoto Mizumura, Satoshi Okumura, Sho Toyoda, Atsuo Imagawa, Masao Ogawa, Masayasu Kawasaki
Aim: Bladder ruptures are commonly misdiagnosed as gastrointestinal perforations or intestinal ischemia. If a diagnosis is made preoperatively, conservative treatment is a safe and effective option. We evaluated the validity of using the attenuation value of ascites, measured by non-contrast computed tomography (CT), to identify patients with bladder ruptures. Methods: A retrospective search of our hospital database identified 7 patients with confirmed bladder ruptures between 2007 and 2013...
April 2017: Acute Medicine & Surgery
https://www.readbyqxmd.com/read/29103467/visualization-of-right-adrenal-vein-comparison-with-three-phase-dynamic-contrast-enhanced-ct
#7
Yoshifumi Noda, Satoshi Goshima, Shoma Nagata, Hiroshi Kawada, Nobuyuki Kawai, Hiromi Koyasu, Masayuki Matsuo
PURPOSE: To evaluate the visualization of the right adrenal vein (RAV) on dynamic contrast-enhanced computed tomography (CT) images in patients with primary aldosteronism. MATERIALS AND METHODS: We evaluated 27 consecutive patients with primary aldosteronism who underwent contrast-enhanced dynamic CT and subsequent adrenal venous sampling. Scan delays were 10-, 20- and 60-s after a bolus-tracking program detected that the threshold of a 100 Hounsfield units (HU) increase in the abdominal aorta had been achieved...
November 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/29102154/three-dimensional-printer-generated-patient-specific-phantom-for-artificial-in-vivo-dosimetry-in-radiotherapy-quality-assurance
#8
Takeshi Kamomae, Hidetoshi Shimizu, Takayoshi Nakaya, Kuniyasu Okudaira, Takahiro Aoyama, Hiroshi Oguchi, Masataka Komori, Mariko Kawamura, Kazuhiro Ohtakara, Hajime Monzen, Yoshiyuki Itoh, Shinji Naganawa
Pretreatment intensity-modulated radiotherapy quality assurance is performed using simple rectangular or cylindrical phantoms; thus, the dosimetric errors caused by complex patient-specific anatomy are absent in the evaluation objects. In this study, we construct a system for generating patient-specific three-dimensional (3D)-printed phantoms for radiotherapy dosimetry. An anthropomorphic head phantom containing the bone and hollow of the paranasal sinus is scanned by computed tomography (CT). Based on surface rendering data, a patient-specific phantom is formed using a fused-deposition-modeling-based 3D printer, with a polylactic acid filament as the printing material...
October 25, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/29084303/a-numeric-analysis-of-bone-density-in-the-edentulous-interforaminal-region
#9
Patrick Tavitian, Michel Ruquet, Chloe Mensé, Emmanuel Nicolas, Olivier Hue
PURPOSE: The purpose of this study was to assess the density of interforaminal bone using quantitative computed tomography (QCT) in simulated case histories to be prescribed an All-on-Five fixed implant treatment protocol. MATERIALS AND METHODS: QCT scans from 30 edentulous patients (15 men and 15 women; mean age 63.33 ± 9.3 years) were analyzed using the Nobel Clinician software. Densities (in Hounsfield units [HU]) were recorded at the neck, middle part of the body, and apex of the lingual and buccal parts of proposed implant sites...
November 2017: International Journal of Prosthodontics
https://www.readbyqxmd.com/read/29080987/radiation-dose-reduction-through-combining-positron-emission-tomography-computed-tomography-pet-ct-and-diagnostic-ct-in-children-and-young-adults-with-lymphoma
#10
Zhihua Qi, Erica L Gates, Maureen M O'Brien, Andrew T Trout
BACKGROUND: Both [F-18]2-fluoro-2-deoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) and diagnostic CT are at times required for lymphoma staging. This means some body segments are exposed twice to X-rays for generation of CT data (diagnostic CT + localization CT). OBJECTIVE: To describe a combined PET/diagnostic CT approach that modulates CT tube current along the z-axis, providing diagnostic CT of some body segments and localization CT of the remaining body segments, thereby reducing patient radiation dose...
October 28, 2017: Pediatric Radiology
https://www.readbyqxmd.com/read/29076750/investigation-of-dental-cone-beam-ct-pixel-data-and-a-modified-method-for-conversion-to-hounsfield-units-hu
#11
Dennise Magill, Natalie Beckmann, Marc A Felice, Thomas Yoo, Minou Luo, Mel Mupparapu
OBJECTIVES: To investigate the relationship in dental Cone-Beam CT (CBCT) between the manufacturer-reported image pixel data and a modified conversion to CT number densities in Hounsfield Units (HU). METHODS: A standardized CT phantom was imaged using typical clinical parameters on CBCT from 3 manufacturers (Carestream 9300®, J Morita 3D Accutomo®, and Planmeca Promax 3D®). Reconstructed axial slices were evaluated using regions of interest to ascertain the mean pixel value in 5 materials in the phantom...
October 27, 2017: Dento Maxillo Facial Radiology
https://www.readbyqxmd.com/read/29076458/feasibility-of-mr-only-proton-dose-calculations-for-prostate-cancer-radiotherapy-using-a-commercial-pseudo-ct-generation-method
#12
Matteo Maspero, Cornelis A T Van den Berg, Guillaume Landry, Claus Belka, Katia Parodi, Peter R Seevinck, Bas W Raaymakers, Christopher Kurz
A magnetic resonance (MR)-only radiotherapy workflow can reduce cost, radiation exposure and uncertainties introduced by CT-MRI registration. A crucial prerequisite is generating the so called pseudo-CT (pCT) images for accurate dose calculation and planning. Many pCT generation methods have been proposed in the scope of photon radiotherapy. This work aims at verifying for the first time whether a commercially available photon-oriented pCT generation method can be employed for accurate intensity-modulated proton therapy (IMPT) dose calculation...
October 27, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29055617/qualitative-and-quantitative-radiological-analysis-of-non-contrast-ct-is-a-strong-indicator-in-patients-with-acute-pyelonephritis
#13
Fadi El-Merhi, May Mohamad, Ali Haydar, Lena Naffa, Rami Nasr, Nadine Hamieh, Ziad Tayara, Charbel Saade
OBJECTIVE: To evaluate the performance of non-contrast computed tomography (CT) by reporting the difference in attenuation between normal and inflamed renal parenchyma in patients clinically diagnosed with acute pyelonephritis (APN). MATERIAL AND METHODS: This is a retrospective study concerned with non-contrast CT evaluation of 74 patients, admitted with a clinical diagnosis of APN and failed to respond to 48h antibiotics treatment. Mean attenuation values in Hounsfield units (HU) were measured in the upper, middle and lower segments of the inflamed and the normal kidney of the same patient...
September 18, 2017: American Journal of Emergency Medicine
https://www.readbyqxmd.com/read/29050958/metal-artefact-reduction-for-accurate-tumour-delineation-in-radiotherapy
#14
David Gergely Kovacs, Laura A Rechner, Ane L Appelt, Anne K Berthelsen, Junia C Costa, Jeppe Friborg, Gitte F Persson, Jens Peter Bangsgaard, Lena Specht, Marianne C Aznar
BACKGROUND AND PURPOSE: Two techniques for metal artefact reduction for computed tomography were studied in order to identify their impact on tumour delineation in radiotherapy. MATERIALS AND METHODS: Using specially designed phantoms containing metal implants (dental, spine and hip) as well as patient images, we investigated the impact of two methods for metal artefact reduction on (A) the size and severity of metal artefacts and the accuracy of Hounsfield Unit (HU) representation, (B) the visual impact of metal artefacts on image quality and (C) delineation accuracy...
October 16, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29046963/cone-beam-computed-tomography-and-ultrasonography-imaging-of-benign-intraosseous-jaw-lesion-a-prospective-radiopathological-study
#15
Ibrahim Sevki Bayrakdar, Ahmet Berhan Yilmaz, Fatma Caglayan, Umit Ertas, Cemal Gundogdu, Ismail Gumussoy
OBJECTIVE: We assessed whether ultrasonography (US) can be used in combination with cone beam computed tomography (CBCT) to image intraosseous jaw lesions. MATERIAL AND METHODS: Using CBCT and US, we evaluated 123 lytic intraosseous jaw lesions diagnosed in 121 patients with guidance from the CBCT findings. The lesions were classified into two groups based on histopathological evaluation: (1) cysts and (2) tumors and tumor-like lesions. US and histopathological findings on the lesions of the two groups and their relationships with each other were also assessed...
October 18, 2017: Clinical Oral Investigations
https://www.readbyqxmd.com/read/29029863/changes-in-local-bone-density-in-early-thumb-carpometacarpal-joint-osteoarthritis
#16
Joseph J Schreiber, Thomas J McQuillan, Eni Halilaj, Joseph J Crisco, Arnold-Peter Weiss, Tarpit Patel, Deborah Kenney, Amy L Ladd
PURPOSE: Thumb carpometacarpal (CMC) osteoarthritis (OA) represents a major source of functional morbidity. The effects of early CMC OA on loading and use patterns potentially lead to changes in local bone density and microarchitecture. Hounsfield units (HU), a quantitative attenuation coefficient obtained from computed tomography (CT) scans, have been shown to be a reliable marker of bone density. We hypothesized that early CMC OA is associated with lower local bone density about the CMC joint as assessed by HU...
October 10, 2017: Journal of Hand Surgery
https://www.readbyqxmd.com/read/29024279/computed-tomographic-lymphography-as-a-complementary-technique-for-lymph-node-staging-in-dogs-with-malignant-tumors-of-various-sites
#17
Federica Rossi, Maximilian Körner, José Suárez, Gregorio Carozzi, Valeria S Meier, Malgorzata Roos, Carla Rohrer Bley
Locoregional lymph nodes are routinely examined in order to define the spatial extent of neoplastic disease. As draining patterns of certain tumor types can be divergent from expected anatomical distribution, it is critical to sample the lymph nodes truly representing the draining area. The aim of this bicenter prospective pilot study was to describe the technique of computed tomographic (CT)-lymphography for primary draining lymph node mapping in tumor staging in dogs. Forty-five dogs with macro- or microscopic tumors in specified localizations were evaluated...
October 11, 2017: Veterinary Radiology & Ultrasound
https://www.readbyqxmd.com/read/28994151/negative-hepatic-computed-tomographic-attenuation-pattern-in-a-dog-with-vacuolar-hepatopathy-and-hepatic-fat-accumulation-secondary-to-cushing-s-syndrome
#18
Andrea Carloni, Michaela Paninarova, Damiano Cavina, Mariarita Romanucci, Leonardo Della Salda, Simone Teodori, Massimo Vignoli
This report describes an unusual computed tomographic (CT) hepatic pattern, characterized by negative attenuation values (from -19.59 to -28.85 Hounsfield Units, HU) in a canine patient with severe Cushing's syndrome. Attenuation values of the splenic parenchyma (63.26 HU) and abdominal fat (-118.34 HU) were within normal limits. The negative hepatic attenuation values allowed a CT diagnosis of severe hepatic fatty infiltration that was subsequently confirmed by tissue-core biopsy and histopathological examination...
October 9, 2017: Veterinary Radiology & Ultrasound
https://www.readbyqxmd.com/read/28992232/development-of-a-minipig-physical-phantom-from-ct-data
#19
Sooyeun Park, Pilsoo Lee, Wi-Ho Ha, Han Sung Kim, Byeong Ryong Park, Jae Seok Kim, Sehwan Shim, Sunhoo Park, Young-Su Kim, Chan Hyeong Kim, Young-Woo Jin
Quantification of pathological progression of radiation-induced injury is essential in development of treatment methods, and a proper animal model is necessary for relevant radiological and medical studies. A minipig is a current animal model selected because of its similarities to humans in anatomy and pathology. In the present study, a minipig physical phantom was developed using computed tomography (CT) data. For dosimetry purposes, the minipig physical phantom was constructed on a slice-by-slice basis, with an array of holes to accommodate dosimeters...
September 1, 2017: Journal of Radiation Research
https://www.readbyqxmd.com/read/28987683/influence-of-fissure-integrity-on-quantitative-ct-and-emphysema-distribution-in-emphysema-type-copd-using-a-dedicated-copd-software
#20
Jan Müller, Hyun-Ju Lim, Monika Eichinger, Bertram J Jobst, Ralf Eberhardt, Daniela Gompelmann, Marcel Koenigkam-Santos, Michael Puderbach, Hans-Ulrich Kauczor, Claus P Heussel, Mark O Wielpütz
OBJECTIVES: Fissure integrity (FI) plays a key role in selecting patients for interventional emphysema therapy. We investigated its interference with automated lobar segmentation in quantitative computed tomography (CT) and emphysema distribution. METHODS: CT was available for 50 patients with chronic obstructive pulmonary disease (COPD). Lobe segmentation was performed fully automated by software and corrected manually. FI was evaluated visually using a %-scale...
October 2017: European Journal of Radiology
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