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Low dose computed tomography

Kihong Son, Jin Sung Kim, Hoyeon Lee, Seungryong Cho
This study investigates dose distribution due to kV cone-beam computed tomography (CBCT) for the patients undergoing CBCT-based image-guided radiation therapy (IGRT). The kV-CBCT provides an efficient image-guidance tool for acquiring the latest volumetric image of a patient's anatomy, and has been being routinely used in clinics for an accurate treatment setup. Imaging radiation doses resulting from six different acquisition protocols of the on-board imager (OBI) were calculated using a Geant4 Application for Tomographic Emission (GATE) Monte Carlo simulation toolkit, and the absorbed doses by various organs were analyzed for the adult and pediatric numerical XCAT phantoms in this study...
October 20, 2016: Radiation Protection Dosimetry
Søren Hess, Evan C Frary, Oke Gerke, Poul Henning Madsen
Pulmonary embolism (PE) is a common, ubiquitous, and potentially lethal disease. As symptoms and clinical findings are notoriously nonspecific, diagnostic imaging is essential to avoid undertreatment as well as overtreatment. Controversies remain regarding first-line imaging in suspected PE. The two main contemporary contenders are ventilation/perfusion scintigraphy with single-photon emission computed tomography (V/Q SPECT) with or without additional low-dose CT (SPECT/CT) and CT angiography (CTA). We present our results from a systematic review and meta-analysis of the diagnostic performances of these modalities: V/Q SPECT, V/Q SPECT/CT, and CTA are all viable options, but we consider V/Q SPECT/CT to be superior in most clinical settings with better overall diagnostic performance, that is, pooled sensitivities (97...
October 20, 2016: Seminars in Thrombosis and Hemostasis
Brad T Morrow, William B Albright, Rogerio I Neves, Michael J Wilkinson, Thomas D Samson
BACKGROUND: Congenital anophthalmia is a rare anomaly that results in micro-orbitism and craniofacial microsomia. Treatment with static conformers is labor-intensive and provides minimal stimulation for orbital growth that requires eventual reconstruction with orbital osteotomies after skeletal maturity. METHODS: A protocol for the treatment of congenital anophthalmia is presented. Patients underwent a preoperative low-dose radiation computed tomography (CT) scan of the facial bones to assess orbital volume...
October 2016: Journal of Craniofacial Surgery
Hsueh-Yu Li, Yu-Lun Lo, Chao-Jan Wang, Li-Jen Hsin, Wan-Ni Lin, Tuan-Jen Fang, Li-Ang Lee
Surgical success for obstructive sleep apnea (OSA) depends on identifying sites of obstruction in the upper airway. In this study, we investigated sites of obstruction by evaluating dynamic changes in the upper airway using drug-induced sleep computed tomography (DI-SCT) in patients with OSA. Thirty-five adult patients with OSA were prospectively enrolled. Sleep was induced with propofol under light sedation (bispectral index 70-75), and low-dose 320-detector row CT was performed for 10 seconds over a span of 2-3 respiratory cycles with supporting a continuous positive airway pressure model...
October 20, 2016: Scientific Reports
Kazuhiko Yoshimatsu, Hajime Yokomizo, Yuki Yano, Sachiyo Okayama, Masaya Satake, Yasufumi Yamada, Shunichi Shiozawa, Takeshi Shimakawa, Takao Katsube, Shungo Endo, Hiroyuki Kato, Yoshihiko Naritaka
A 57-year-old woman had been diagnosed with sigmoid colon cancer at surgery for ovarian cancer, and underwent simultaneous radical resection. Because of the pathological diagnosis of sigmoid cancer with ovarian metastasis, adjuvant chemotherapy was scheduled, with Leucovorin(LV)25 mg. This was immediately followed with 5-fluorouracil(5-FU)500 mg, via a 2-hour systemic intravenous infusion daily for 5 consecutive days, with courses repeated at 5 weeks, followed by maintenance once every 1 or 2 weeks for 2 years...
October 2016: Gan to Kagaku Ryoho. Cancer & Chemotherapy
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
Hui Zhang, Shucai Zhang
Lung cancer is the leading cause of cancer mortality currently. Early diagnosis is crucial to the good prognosis of lung cancer. Evidence has shown that low-dose computed tomography (CT) screening can make the decline in the mortality of lung cancer. However, there are still many problems in the screening, such as, high false-positive rates, overdiagnosis and radiation exposure. As another non-invasive tumor screening method, blood-based tumor markers showed a high sensitivity and specificity in early diagnosis of lung cancer in recent years...
October 20, 2016: Zhongguo Fei Ai za Zhi, Chinese Journal of Lung Cancer
Felipe P Andrade, Roberto Montoro, Renan Oliveira, Gabriela Loures, Luana Flessak, Roberta Gross, Camille Donnabella, Andrea Puchnick, Lisa Suzuki, Rodrigo Regacini
OBJECTIVES: 1) To verify clinical signs correlated with appropriate cranial computed tomography scan indications and changes in the therapeutic approach in pediatric minor head trauma scenarios. 2) To estimate the radiation exposure of computed tomography scans with low dose protocols in the context of trauma and the additional associated risk. METHODS: Investigators reviewed the medical records of all children with minor head trauma, which was defined as a Glasgow coma scale ≥13 at the time of admission to the emergency room, who underwent computed tomography scans during the years of 2013 and 2014...
October 1, 2016: Clinics
Charbel Saade, Fadi El-Merhi, Bassam El-Achkar, Racha Kerek, Thomas J Vogl, Gilbert Georges Maroun, Lamia Jamjoom, Hussain Al-Mohiy, Lena Naffa
CLINICAL RELEVANCE STATEMENT: Caudocranial scan direction and contrast injection timing based on measured patient vessel dynamics can significantly improve arterial and aneurysmal opacification and reduce both contrast and radiation dose in the assessment of thoracic aortic aneurysms (TAA) using helical thoracic computed tomography angiography (CTA). OBJECTIVES: To investigate opacification of the thoracic aorta and TAA using a caudocranial scan direction and a patient-specific contrast protocol...
October 17, 2016: Journal of Computer Assisted Tomography
Xue Rui, Yannan Jin, Paul F FitzGerald, Mingye Wu, Adam M Alessio, Paul E Kinahan, Bruno De Man
Computed tomography (CT) has been used for a variety of applications, two of which include diagnostic imaging and attenuation correction for PET or SPECT imaging. Ideally, the x-ray tube spectrum should be optimized for the specific application to minimize the patient radiation dose while still providing the necessary information. In this study, we proposed a projection-based analytic approach for the analysis of contrast, noise, and bias. Dose normalized contrast to noise ratio (CNRD), inverse noise normalized by dose (IND) and bias are used as evaluation metrics to determine the optimal x-ray spectrum...
November 7, 2016: Physics in Medicine and Biology
Sameer Bakhshi, Sainath Bhethanabhotla, Rakesh Kumar, Krishankant Agarwal, Punit Sharma, Sanjay Thulkar, Arun Malhotra, Deepa Dhawan, Sreenivas Vishnubhatla
BACKGROUND: Data about significance of (18)F-FDG positron emission tomography (PET) at interim assessment and end of treatment in pediatric Hodgkin lymphoma (HL) are limited. METHODS: Patients (≤18 years) with HL were prospectively evaluated with contrast-enhanced computed tomography (CECT) and PET combined with low-dose CT(PET-CT) at baseline, post 2 cycles of chemotherapy and post completion of treatment. Revised international working group criteria (RIW) and Deauville (DA) five point-scale for response assessment by PET-CT were used...
October 6, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Lawrence Lechuga, Georg A Weidlich
A comparison of image quality and dose delivered between two differing computed tomography (CT) imaging modalities-fan beam and cone beam-was performed. A literature review of quantitative analyses for various image quality aspects such as uniformity, signal-to-noise ratio, artifact presence, spatial resolution, modulation transfer function (MTF), and low contrast resolution was generated. With these aspects quantified, cone beam computed tomography (CBCT) shows a superior spatial resolution to that of fan beam, while fan beam shows a greater ability to produce clear and anatomically correct images with better soft tissue differentiation...
September 12, 2016: Curēus
Zhongyi Yang, Huiyu Yuan, Xiaoping Xu, Bingxin Gu, Mingwei Wang, Jianping Zhang, Yongping Zhang, Yingjian Zhang
The purpose of the preliminary study was to investigate whether high specific activity (SA) of (18) F-fluoroestradiol was optimal in breast cancer diagnosis. Imaging at variable SA was conducted in a ZR-75-1 xenograft model of estrogen-receptor positive human breast cancer in 6 mice. The region of interest was manually drawn, and the percent of injected dose per gram of the tumor and muscle in the regions of interest were recorded. Tumor-to-muscle ratio (T/M) was calculated and compared in each group with different SAs...
October 13, 2016: Journal of Labelled Compounds & Radiopharmaceuticals
Florence Paques, Etienne Hamoir, Pierre Lovinfosse, Roland Hustinx, Nadia Withofs
We present the case of a 48-year-old patient with a left adrenal incidentaloma found on computed tomography (CT) for which the diagnosis of pheochromocytoma was confirmed by a 24-hour urinary dosage of norepinephrine. The (123)I-mIBG scintigraphy showed a high uptake of (123)I-mIBG in the left adrenal gland and, additionally, the single photon emission computed tomography combined with a low-dose CT (SPECT/CT) suggested the extension into the adrenal vein. The diagnostic CT and magnetic resonance images agreed with these findings and the subsequent surgery confirmed the vascular invasion...
October 13, 2016: Acta Chirurgica Belgica
Jantina C de Groot, Huib Storm, Marijke Amelink, Selma B de Nijs, Edwin Eichhorn, Bennie H Reitsma, Elisabeth H D Bel, Anneke Ten Brinke
Adult-onset eosinophilic asthma is increasingly recognised as a severe and difficult-to-treat subtype of asthma. In clinical practice, early recognition of patients with this asthma subtype is important because it may have treatment implications. Therefore, physicians need to know the distinct characteristics of this asthma phenotype. The objective of the present study was to determine the characteristic profile of patients with adult-onset eosinophilic asthma. 130 patients with adult-onset (>18 years of age) asthma and high blood eosinophil counts (≥0...
April 2016: ERJ Open Research
Ming Li, Cheng Zhang, Chengtao Peng, Yihui Guan, Pin Xu, Mingshan Sun, Jian Zheng
Low-dose computed tomography (CT) reconstruction is a challenging problem in medical imaging. To complement the standard filtered back-projection (FBP) reconstruction, sparse regularization reconstruction gains more and more research attention, as it promises to reduce radiation dose, suppress artifacts, and improve noise properties. In this work, we present an iterative reconstruction approach using improved smoothed l0 (SL0) norm regularization which is used to approximate l0 norm by a family of continuous functions to fully exploit the sparseness of the image gradient...
2016: BioMed Research International
Zhiguo Zhou, Haixi Chen, Wei Wei, Shanghui Zhou, Jingbo Xu, Xifu Wang, Qingguo Wang, Guixiang Zhang, Zhuoli Zhang, Linfeng Zheng
PURPOSE: The purpose of this study was to evaluate the image quality and radiation dose in computed tomography urography (CTU) images acquired with a low kilovoltage peak (kVp) in combination with an adaptive statistical iterative reconstruction (ASiR) algorithm. METHODS: A total of 45 subjects (18 women, 27 men) who underwent CTU with kV assist software for automatic selection of the optimal kVp were included and divided into two groups (A and B) based on the kVp and image reconstruction algorithm: group A consisted of patients who underwent CTU with a 80 or 100 kVp and whose images were reconstructed with the 50% ASiR algorithm (n=32); group B consisted of patients who underwent CTU with a 120 kVp and whose images were reconstructed with the filtered back projection (FBP) algorithm (n=13)...
2016: American Journal of Translational Research
Yosuke Kunishi, Koichiro Yoshie, Mitsuyasu Ota, Yoriko Kuboi, Masatomo Kanno, Satoshi Tanaka, Takafumi Yanagibashi, Mao Matsubayashi, Yoshiteru Hao, Yoichi Kameda
An 83-year-old male presented with distended abdomen. A computed tomography scan demonstrated pleural effusion, ascites, peritoneal thickness, and panniculitis. Multiple small white nodules of peritoneum were observed during a laparoscopy examination, and biopsy specimens revealed noncaseating granulomas. Gallium scintigram demonstrated an accumulation in the peritoneum and revealed a panda sign that has been described as an indication of sarcoidosis. Although sarcoidosis rarely induces peritonitis with ascites, peritoneal sarcoidosis was diagnosed and he began receiving steroid therapy...
2016: Nihon Shokakibyo Gakkai Zasshi, the Japanese Journal of Gastro-enterology
Kevin P Murphy, Liam J Healy, Lee Crush, Maria Twomey, Fiachra Moloney, Sylvia Sexton, Owen J O'Connor, Michael M Maher
AIM: To assess the effect of neutral (NC) and positive (PC) oral contrast use on patient dose in low-dose abdominal computed tomography (CT). METHODS: Low-dose clinically indicated CTs were performed on 79 Crohn's patients (35 = PC, 1 L 2% gastrografin; 44 = NC, 1.5 L polyethylene glycol). Scanner settings for both acquisitions were identical apart from 25 s difference in intravenous contrast timing. Body mass index (BMI), scan-ranges, dose-length product and size-specific dose estimated were recorded...
September 28, 2016: World Journal of Radiology
Annette M Ilg, Aaron A Laviana, Mitchell Kamrava, Darlene Veruttipong, Michael Steinberg, Sang-June Park, Michael A Burke, Douglas Niedzwiecki, Patrick A Kupelian, Christopher Saigal
PURPOSE: Cost estimates through traditional hospital accounting systems are often arbitrary and ambiguous. We used time-driven activity-based costing (TDABC) to determine the true cost of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy for prostate cancer and demonstrate opportunities for cost containment at an academic referral center. METHODS AND MATERIALS: We implemented TDABC for patients treated with I-125, preplanned LDR and computed tomography based HDR brachytherapy with two implants from initial consultation through 12-month followup...
October 3, 2016: Brachytherapy
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