Individualized Radiation Dose Control

Study Overview
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Brief Summary
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The adjustment of radiation dose in many CT protocol are based on body mass index(BMI) or weight of the patient. In the literature, neck circumference (NC) has been reported as a new anthropometric parameter indicating the body mass for the upper body. NC may be an important landmark in the determination of the low dose protocols for upper body CT examinations such as neck, chest and coronary CT.

Detailed Description
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Over the last few decades, MDCT(multidetector computed tomography), cardiac imaging, CT perfusion techniques, high-pitch CT, and dual-energy CT have been introduced to clinical practice, increasing the overall amount of radiation applied. There are two types of approaches in accordance with the as low as reasonably achievable (ALARA) principle in MDCT. One of them is related to new technology products and different imaging techniques such as dose modulation along the x-, y-, and z-axes (anatomical tube current modulation, ECG-controlled tube current modulation or dynamically adjustable pre-patient collimation of the X-ray beam in the z-axis direction, iterative reconstruction technique. The other strategy is individualized screening-dose protocols based on body size. However the radiologist is facing the challenge of providing diagnostic image quality at the lowest radiation dose. Body mass index (BMI) is not only the most widely used anthropometric tool for defining overweight and obesity, but it is also the most commonly reported body index for adjusting low dose in MDCT.Despite this popularity of BMI, it is becoming increasingly more clear that BMI is not a good surrogate for regional adiposity. Regional fat deposition, especially in the upper body region, is a better predictor of some obesity related complications than BMI. Accordingly, it has been reported that several anthropometric parameters of the chest might serve as a surrogate instead of BMI for individualized dose settings Neck circumference(NC) is a kind of somatometric parameter like wrist or hip circumference that reflects the upper body size. NC may be an important landmark in the determination of the low dose protocols for upper body CT examinations such as neck, chest and coronary CT. Although investigators have not encountered studies in the literature, this point will be evaluated in our study.The purpose of this study is to evaluate if NC is an appropriate and a novel parameter for adjusting and reduction of the effective chest CT radiation doses in comparison with BMI or not.

Official Title
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Individualized Radiation Dose Control: Could Neck Circumference be a New Somatometric Parameter to Adjust Tube Current for Thorax CT?

Conditions
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Radiation Exposure

Intervention / Treatment
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* Radiation: computed tomography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: clinical diagnosis of pulmonary diseases participants who can be referred to radiology for diagnostic imaging participants who allowed to be taken somatometric measurements Exclusion Criteria: participants who did not allow to be taken somatometric measurements participants with incomplete data (such as missing weight or height data) pediatric and pregnant patients

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: The patients underwent thorax CT<br>The patients refered to radiology service underwent thorax computed tomography without contrast material for the evaluation of various complaints such as dyspnea, hemoptysis and pulmonary infections. | Radiation: computed tomography<br>* low dose protocol of thorax ct<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The measurement of neck circumference of the patients undergoing non-enhanced thorax CT | Before CT examination, during patient preparation, neck circumference was measured horizontally at the level of the cyricoid cartilage by a non-elastic flexible tape (centimeter, cm) | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The measurement of weight of the patients undergoing non-enhanced thorax CT | Before CT examination, during patient preparation, patient weight was measured by a bascule (kilogram, kg) | 1 year | 
| The measurement of height of the patients undergoing non-enhanced thorax CT | Before CT examination, during patient preparation, patient height was measured with a stadiometer (milimeter, mm) | 1 year | 
| Calculating the body mass index (BMI) using the results of each patient measured in outcome 2 and outcome 3. | calculation of data with a spesific formula (kg/mm²) | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Thorax CT, Low Dose, Body Mass Index, Neck Circumference