Is abdominal x-ray (AXR) or computed tomography (CT) of the abdomen the most appropriate imaging modality for the detection of illegal substances concealed, taking into consideration the sensitivity, specificity and radiation dose?

2019 ◽  
Vol 16 ◽  
pp. 50-56 ◽  
Author(s):  
Kiki Lan ◽  
Edel Doyle
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Imaging Modality ◽  
X Ray ◽  
Sensitivity Specificity

scholarly journals Appropriate abdominal imaging for the emergency department patient

2021 ◽  
Vol 51 (1) ◽  
pp. 169
Author(s):  
Danielle R. Knott
Keyword(s):  
Computed Tomography ◽  
Emergency Department ◽  
Radiation Dose ◽  
Diagnostic Imaging ◽  
Low Dose ◽  
Imaging Modality ◽  
X Ray ◽  
Statistical Iterative Reconstruction ◽  
Imaging Appropriateness ◽  
Ray Series

Abdominal x-ray series (AXR) and abdominal CT scans (ACT) are commonly performed to aid in the diagnosis for patients who present to the emergency room with abdominal pain. Patients commonly receive both an AXR and ACT, due to a lack of knowledge regarding imaging appropriateness among healthcare professionals who order these exams. A primary simple retrospective data-analysis was performed to understand the prevalence of how often both exams were ordered in three Nova Scotia emergency departments. A literature review was also conducted to compare the diagnostic accuracy of each diagnostic imaging modality. Several articles showed that patients who have an AXR also have an ACT that demonstrates an abnormal finding. Emergency department physicians are not reassured when abdominal x-rays are negative and do not show abnormal findings, and as a result, a CT scan is also performed. Radiation dose must be considered when ordering multiple diagnostic imaging exams. A low-dose CT (LDCT) can be used to reduce the radiation exposure to the patient, while maintaining high diagnostic quality images. Image quality can be enhanced at a reduced radiation dose by using an image reconstruction technique such as adaptive statistical iterative reconstruction (ASIR). Understanding the most appropriate abdominal imaging modality for emergency department patients allows for fewer examinations being ordered and a reduction of radiation dose to the patient. When the most appropriate imaging is performed, a definitive diagnosis can be made and the best treatment can be provided to patients. This information can help to create an imaging appropriateness protocol for emergency departments.Additional research can help determine the cost differences between the two exams and the influence a protocol change could have on the emergency and diagnostic imaging departments.Keywords: AXR – Abdominal x-ray series, ACT – Abdominal computed tomography scan, CT – Computed tomography, SDCT – Standard-dose CT, LDCT – Low-dose CT, ASIR – Adaptative statistical iterative reconstruction FBP – Filtered back projection, CTDIvol – Volume computed tomography dose index

scholarly journals Efficacy of chest X-ray in the diagnosis of COVID-19 pneumonia: comparison with computed tomography through a simplified scoring system designed for triage

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Akın Çinkooğlu ◽  
Selen Bayraktaroğlu ◽  
Naim Ceylan ◽  
Recep Savaş
Keyword(s):  
Computed Tomography ◽  
Intensive Care ◽  
Intensive Care Units ◽  
Scoring System ◽  
Imaging Modality ◽  
Ground Glass Opacity ◽  
Initial Presentation ◽  
X Ray ◽  
Chest X Ray

Abstract Background There is no consensus on the imaging modality to be used in the diagnosis and management of Coronavirus disease 2019 (COVID-19) pneumonia. The purpose of this study was to make a comparison between computed tomography (CT) and chest X-ray (CXR) through a scoring system that can be beneficial to the clinicians in making the triage of patients diagnosed with COVID-19 pneumonia at their initial presentation to the hospital. Results Patients with a negative CXR (30.1%) had significantly lower computed tomography score (CTS) (p < 0.001). Among the lung zones where the only infiltration pattern was ground glass opacity (GGO) on CT images, the ratio of abnormality seen on CXRs was 21.6%. The cut-off value of X-ray score (XRS) to distinguish the patients who needed intensive care at follow-up (n = 12) was 6 (AUC = 0.933, 95% CI = 0.886–0.979, 100% sensitivity, 81% specificity). Conclusions Computed tomography is more effective in the diagnosis of COVID-19 pneumonia at the initial presentation due to the ease detection of GGOs. However, a baseline CXR taken after admission to the hospital can be valuable in predicting patients to be monitored in the intensive care units.

scholarly journals Radiation dose estimation for pencil beam X-ray luminescence computed tomography imaging

2021 ◽  
pp. 1-12
Author(s):  
Ignacio O. Romero ◽  
Changqing Li
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Small Animal ◽  
Pencil Beam ◽  
Computed Tomography Imaging ◽  
Step Size ◽  
Imaging Protocol ◽  
X Ray ◽  
Beam Geometry ◽  
Muscle Tissues

BACKGROUND: Pencil beam X-ray luminescence computed tomography (XLCT) imaging provides superior spatial resolution than other imaging geometries like sheet beam and cone beam geometries. However, the pencil beam geometry suffers from long scan times, resulting in concerns overdose which discourages the use of pencil beam XLCT. OBJECTIVE: The dose deposited in pencil beam XLCT imaging was investigated to estimate the dose from one angular projection scan with three different X-ray sources. The dose deposited in a typical small animal XLCT imaging was investigated. METHODS: A Monte Carlo simulation platform, GATE (Geant4 Application for Tomographic Emission) was used to estimate the dose from one angular projection scan of a mouse leg model with three different X-ray sources. Dose estimations from a six angular projection scan by three different X-ray source energies were performed in GATE on a mouse trunk model composed of muscle, spine bone, and a tumor. RESULTS: With the Sigray source, the bone marrow of mouse leg was estimated to have a radiation dose of 44 mGy for a typical XLCT imaging with six angular projections, a scan step size of 100 micrometers, and 106 X-ray photons per linear scan. With the Sigray X-ray source and the typical XLCT scanning parameters, we estimated the dose of spine bone, muscle tissues, and tumor structures of the mouse trunk were 38.49 mGy, 15.07 mGy, and 16.87 mGy, respectively. CONCLUSION: Our results indicate that an X-ray benchtop source (like the X-ray source from Sigray Inc.) with high brilliance and quasi-monochromatic properties can reduce dose concerns with the pencil beam geometry. Findings of this work can be applicable to other imaging modalities like X-ray fluorescence computed tomography if the imaging protocol consists of the pencil beam geometry.

Using 100- instead of 120-kVp computed tomography to diagnose pulmonary embolism almost halves the radiation dose with preserved diagnostic quality

2010 ◽  
Vol 51 (3) ◽  
pp. 260-270 ◽  
Author(s):  
Peter Björkdahl ◽  
Ulf Nyman
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Image Quality ◽  
Radiation Dose ◽  
Effective Dose ◽  
Ct Number ◽  
Subjective Image Quality ◽  
Diagnostic Quality ◽  
X Ray ◽  
Tube Potential

Background: Concern has been raised regarding the mounting collective radiation doses from computed tomography (CT), increasing the risk of radiation-induced cancers in exposed populations. Purpose: To compare radiation dose and image quality in a chest phantom and in patients for the diagnosis of pulmonary embolism (PE) at 100 and 120 peak kilovoltage (kVp) using 16-multichannel detector computed tomography (MDCT). Material and Methods: A 20-ml syringe containing 12 mg I/ml was scanned in a chest phantom at 100/120 kVp and 25 milliampere seconds (mAs). Consecutive patients underwent 100 kVp ( n = 50) and 120 kVp ( n = 50) 16-MDCT using a “quality reference” effective mAs of 100, 300 mg I/kg, and a 12-s injection duration. Attenuation (CT number), image noise (1 standard deviation), and contrast-to-noise ratio (CNR; fresh clot = 70 HU) of the contrast medium syringe and pulmonary arteries were evaluated on 3-mm-thick slices. Subjective image quality was assessed. Computed tomography dose index (CTDIvol) and dose–length product (DLP) were presented by the CT software, and effective dose was estimated. Results: Mean values in the chest phantom and patients changed as follows when X-ray tube potential decreased from 120 to 100 kVp: attenuation +23% and +40%, noise +38% and +48%, CNR −6% and 0%, and CTDIvol −38% and −40%, respectively. Mean DLP and effective dose in the patients decreased by 42% and 45%, respectively. Subjective image quality was excellent or adequate in 49/48 patients at 100/120 kVp. No patient with a negative CT had any thromboembolism diagnosed during 3-month follow-up. Conclusion: By reducing X-ray tube potential from 120 to 100 kVp, while keeping all other scanning parameters unchanged, the radiation dose to the patient may be almost halved without deterioration of diagnostic quality, which may be of particular benefit in young individuals.

Percutaneous Computed Tomography-Guided Lung Biopsies: Preliminary Results using an Augmented Reality Navigation System

2012 ◽  
Vol 98 (6) ◽  
pp. 775-782 ◽  
Author(s):  
Rosario Francesco Grasso ◽  
Giacomo Luppi ◽  
Roberto Luigi Cazzato ◽  
Eliodoro Faiella ◽  
Francesco D'Agostino ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Augmented Reality ◽  
Radiation Dose ◽  
Navigation System ◽  
Ct Scans ◽  
Ultrasound Images ◽  
Procedure Time ◽  
Ct Guided ◽  
X Ray ◽  
Lung Biopsies

Aims and background “Augmented reality” is a technique to create a composite view by augmenting the real intervention field, visualized by the doctor, with additional information coming from a virtual volume generated using computed tomography (CT), magnetic resonance or ultrasound images previously acquired from the same patient. In the present study we verified the accuracy and validated the clinical use of an augmented reality navigation system produced to perform percutaneous CT-guided lung biopsies. Methods One hundred and eighty consecutive patients with solitary parenchymal lung lesions, enrolled using a nonrandom enrollment system, underwent percutaneous CT-guided aspiration and core biopsy using a traditional technique (group C, 90 patients) and navigation system assistance (group S, 90 patients). For each patient we recorded the largest lesion diameter, procedure time, overall number of CT scans, radiation dose, and complications. The entire experimental project was evaluated and approved by the local institutional review board (ethics committee). Results Each procedure was concluded successfully and a pathological diagnosis was reached in 96% of cases in group S and 90% of cases in group C. Procedure time, overall number of CT scans and incident x-ray radiation dose (CTDIvol) were significantly reduced in navigation system-assisted procedures (P <0.001; z = 5.64) compared with traditional CT-guided procedures. The percentage of procedural complications was 14% in group S and 17% in group C. Conclusion The augmented reality navigation system used in this study was a highly safe, technically reliable and effective support tool in percutaneous CT-guided lung biopsy, allowing to shorten the procedure time and reduce the incident x-ray radiation dose to patients and the rate of insufficient specimens. Furthermore, it has the potential to increase the number of procedures executed in the allocated time without increasing the number of complications.

scholarly journals Computer Based X-Ray Computed Tomography Training System for Engineering Education

2017 ◽  
Vol 9 (3-2) ◽  
Author(s):  
Muhammad Hanif Ramlee ◽  
Jasmy Yunus ◽  
Eko Supriyanto
Keyword(s):  
Computed Tomography ◽  
Imaging Modality ◽  
Training System ◽  
Radiation Hazard ◽  
Ct Scanner ◽  
Virtual Instrumentation ◽  
X Ray ◽  
Computer Based ◽  
X Ray Computed ◽  
Working Principle

X-ray computed tomography (called CT) scanner is a powerful and widely used medical imaging modality in the hospital. The CT machine is very expensive and it can produce dangerous radiation when a person operates the machine. This makes it difficult for biomedical engineers and radiographer students to learn its working principles. In order to overcome this problem, a computer based CT scanner trainer system has been developed. The system is implemented using National Instrument’s Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW). At the beginning, it was started with the studying of existing CT scan machine. After gathering information, development process continued to develop generator component, x-ray tube subsystem, detector subsystem, imaging subsystem, and finally is reconstruction subsystem. The trainer system that has been developed is able to be used to train students on how to use CT scanner especially to get high quality images with lowest possible radiation. This will help biomedical engineers and radiographer students to have a better understanding of CT scanner in term of its working principle and to prevent radiation hazard during the learning process.

scholarly journals Value of Multidetector Computed Tomography in the Assessment of Achalasia Subtypes and Detection of Pulmonary and Thoracic Complications

2019 ◽  
Vol 28 (6) ◽  
pp. 539-546
Author(s):  
Sanja Jovanovic ◽  
Aleksandra Djuric-Stefanovic ◽  
Aleksandar Simić ◽  
Ognjan Skrobic ◽  
Predrag Pesko
Keyword(s):  
Computed Tomography ◽  
Multidetector Computed Tomography ◽  
Wall Thickness ◽  
Imaging Modality ◽  
Correlation Coefficients ◽  
Observer Agreement ◽  
Esophageal Wall ◽  
X Ray ◽  
Chest X Ray ◽  
Diagnostic Work

Objective: To evaluate multidetector computed tomography (MDCT) findings in patients with achalasia, to assess its role in differentiating subtypes in detecting lung involvement and extra-esophageal thoracic complications. Subjects and Methods: This clinical retrospective study included 51 patients with manometrically confirmed achalasia who underwent chest X-ray and MDCT in diagnostic work-up. Esophageal wall thickness and morphology, luminal dilatation, lung changes, and extra-esophageal manifestations were analyzed on MDCT by 2 readers. Wilcoxon, Kruskal-Wallis and Mann-Whitney test were used for assessing the differences among the achalasia subtypes, and intra-class correlation coefficients (ICC) assessing the inter-observer agreement between the measurements of 2 readers. Results: Fourteen (27.5%) patients had achalasia subtype I, 21 (60.8%) had subtype II while 6 (11.8%) had subtype III. Esophageal wall thickness of the esophageal body (EB) and distal esophageal segment (DES) as well as nodular/lobulated appearance of DES were found significantly more often in subtype III (p = 0.024, p < 0.001, p = 0.009, respectively). Esophageal dilatation gradually decreased from subtype I to III (p = 0.006). Chest X-ray revealed lung changes in 9 (17%) and MDCT in 21 (41%) patients (p = 0.001), most frequently in subtype I, with predominance of ground-glass opacities. Tracheal/carinal compression was detected in 27 (52.9%) and left atrial compression in 17 (33.3%) patients. Excellent inter-observer agreement was observed in measuring the EB and DES wall thickness, and diameter of EB (ICC 0.829, 0.901, and 0.922). Conclusion: MDCT is a useful tool for detecting lung and extra-esophageal thoracic complications in patients with achalasia, and could be a valuable additional imaging modality in the differentiation of achalasia subtypes.

scholarly journals Role of Computed Tomography Perfusion in Identification of Acute Lacunar Stroke Syndromes

Stroke ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 339-343
Author(s):  
Carlos Garcia-Esperon ◽  
Milanka Visser ◽  
Leonid Churilov ◽  
Ferdinand Miteff ◽  
Andrew Bivard ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Posterior Fossa ◽  
Delay Time ◽  
Imaging Modality ◽  
Lacunar Stroke ◽  
Transient Time ◽  
Predictive Values ◽  
Computed Tomography Perfusion ◽  
Noncontrast Computed Tomography ◽  
Sensitivity Specificity

Background and Purpose: Lacunar syndromes correlate with a lacunar stroke on imaging in 50% to 60% of cases. Computed tomography perfusion (CTP) is becoming the preferred imaging modality for acute stroke triage. We aimed to estimate the sensitivity, specificity, and predictive values for noncontrast computed tomography and CTP in lacunar syndromes, and for cortical, subcortical, and posterior fossa regions. Methods: A retrospective analysis of confirmed ischemic stroke patients who underwent acute CTP and follow-up magnetic resonance imaging between 2010 and 2018 was performed. Brain noncontrast computed tomography and CTP were assessed independently by 2 stroke neurologists. Receiver operating characteristic curve analysis was performed to estimate sensitivity, specificity, and area under the curve (AUC) for the detection of strokes in patients with lacunar syndromes using different CTP maps. Results: We found 106 clinical lacunar syndromes, but on diffusion-weighted imaging, these consisted of 59 lacunar, 33 cortical, and 14 posterior fossa strokes. The discrimination of ischemia identification was very poor using noncontrast computed tomography in all 3 regions, but good for cortical (AUC, 0.82) and poor for subcortical and posterior regions (AUCs, 0.55 and 0.66) using automated core-penumbra maps. The addition of delay time and mean transient time maps substantially increased subcortical (AUC, 0.80) and slightly posterior stroke detection (AUC, 0.69). Conclusions: Analysis of mean transient time and delay time maps in combination with core-penumbra maps improves detection of subcortical and posterior strokes.

scholarly journals The epicondylar ratio can be reliably determined in both computed tomography and X-ray

2021 ◽  
Author(s):  
Bernd Lutz ◽  
Lucia Polcikova ◽  
Martin Faschingbauer ◽  
Heiko Reichel ◽  
Ralf Bieger
Keyword(s):  
Computed Tomography ◽  
Interobserver Agreement ◽  
Imaging Modality ◽  
Intraclass Correlation ◽  
Consecutive Series ◽  
Key Factors ◽  
Reliable Determination ◽  
X Ray ◽  
Medial Side ◽  
Total Knee

Abstract Purpose One of the key factors to the successful revision of total knee arthroplasty (rTKA) is the reconstruction of the joint line, which can be determined using the epicondylar ratio (ER). The measurement is established in X-ray and MRI. However, it is not known whether computed tomography (CT) allows a more reliable determination. The objective was to assess the reliability of the ER in CT and to determine the correlation between the ER in CT and a.p. X-ray of the knee. Methods The ER was determined on X-ray and CT images of a consecutive series of 107 patients, who underwent rTKA. Measurements were made by two blinded observes, one measured twice. The inter- and intraobserver agreement, as well as the correlation between the two methods, were quantified with the Intraclass Correlation Coefficient. Results The average lateral ER was 0.32 (± 0.04) in X-ray and 0.32 (± 0.04) in CT. On the medial side, the average ER was 0.34 (± 0.04) in X-ray and 0.35 (± 0.04) in CT. The interobserver agreement for the same imaging modality was lateral 0.81 and medial 0.81 in X-ray as well as lateral 0.74 and medial 0.85 in CT. The correlation between the two methods was lateral 0.81 and medial 0.79. Conclusions The ER can be reliably determined in X-ray and CT. Measurements of the two image modalities correlate. Prior to rTKA, the sole use of the X-ray is possible.

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