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IRCT20220313054273N2 IRCT 2022-09-27 Shiraz University of Medical Sciences The effect of contrast agent reduction on the image quality of pulmonary Computed Tomography Evaluation of contrast agent reduction on the image quality of pulmonary Computed Tomography using a standard reconstruction available in the conventional CT system 2022-09-23 anticipated 40 Complete https://irct.ir/trial/64650 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Diagnostic, Randomization description: To allocate patients in intervention and control groups, simple random allocation method will be used. We asked the SPSS software to provide us 20 values randomly between 1 to 40. The software gave us the values 5, 3, 13, 18, 2, 14, 10, 1, 35, 37, 23, 32, 8, 16, 33, 36, 39, 9, 22, 28. By drawing lots between the control and intervention groups, we assigned these numbers to the intervention group. Then, the rest of the numbers, between 1 and 40, were assigned to the control group. In this way, we will assign the patients as control and intervention groups right from the beginning of the study, among the patients who were referred to the CT scan department of Namazi hospital, with the suspension of pulmonary embolism and having the inclusion criteria for entering the study. From the above random numbers, the first, second, and third patients are to be included in the intervention group. The intervention group will be scanned by reducing contrast agent protocol (pulmonary CT Angio). The fourth, fifth, and sixth patients referred will be allocated to the control group and they will be scanned by the standard dose of the contrast agent protocol (pulmonary CT Angio). Other referred patients who are candidates for the study will be placed in the intervention or control groups based on the serial number of their referrals and the matching numbers in the above-mentioned allocations, Blinding description: In this study, the investigator (radiologists who evaluate the quality of pulmonary CTA) and patients will not be aware of the scanning protocol (they are blind to the amount of contrast agent). Only, technologists responsible for scanning patients and the students responsible for performing the study are aware of the amount of contrast agent. 3 pulmonary thromboembolism. Intervention 1: Intervention group: Patients suspected of pulmonary embolism referred to Namazi Hospital (Shiraz) will be scanned by contrast agent reduction protocol. The amount of injected contrast agent to the patients in the intervention group will be 0.7 ml/kg of body weight. The Pecnograph contains 300mgI/ml (milligram iodine per millilitre) made in Iran and is the most widely available contrast agent. This contrast agent will be used to scan patients in the intervention group. These patients will be scanned by a 16-Slice LightSpeed GE Healthcare CT system, made in the USA, at 100kVp. The pulmonary CT Angio images of patients in the intervention group will be reconstructed by Filter Back Projection (FBP), made in the USA. FBP is a standard image reconstruction algorithm and is available in conventional CT systems. Conventional CT systems are used to scan patients in most hospitals affiliated with the Shiraz University of Medical Sciences. Intervention 2: Control group: Patients suspected of pulmonary embolism referred to Namazi Hospital (Shiraz) will be scanned by standard protocol (pulmonary CT Angio). The amount of injected contrast agent to the patients in the control group will be 1.0 milliliter per kilogram of the patient’s body weight. The Pecnograph contains 300mgI/ml (milligram iodine per milliliter) made in Iran is the most widely available contrast agent. This contrast agent will be used to scan patients in the control group. The patients in the control group will be scanned by a 16-Slice LightSpeed GE Healthcare CT system, made in the USA, at 120kVp. The pulmonary CT Angio images of patients in the control group will be reconstructed by Filter Back Projection (FBP), made in the USA. FBP is a standard image reconstruction algorithm and is available in conventional CT systems. Conventional CT systems are used to scan patients in most hospitals affiliated with the Shiraz University of Medical Sciences. Yes - There is a plan to make this available What will be shared: Part of the data can be shared after unidentified When: 6 months after publication To whom: Interested researchers in this field Conditions: Using for research works Where to obtain: Research and technology deputy How to obtain: Sending an Email to research and technology deputy. Comments:
public Rezvan Ravanfar Haghighi
Medical Imaging Research Centre, 8th Floor, Mohammad Rasolallah Research Tower, Khalili street
Shiraz Iran (Islamic Republic of) 7193635899 +98 71 3628 1464 sravanfarr@gmail.com Shiraz University of Medical Sciences scientific Rezvan Ravanfar Haghighi
Medical Imaging Research Centre, 8th Floor, Mohammad Rasolallah Research Tower, Khalili street
Shiraz Iran (Islamic Republic of) 7193635899 +98 71 3628 1464 sravanfarr@gmail.com Shiraz University of Medical Sciences Iran (Islamic Republic of) Suspicion pulmonary emboly as seen from clinical indication Abnormal levels of plasma D-dimer Lower extremity deep vein thrombosis 18 years no limit Both Severe pneumonia and atelectasis Confirmed pregnancy or suspected but unconfirmed pregnancy Critically ill patient or patients hospitalized in ICU Allergy to iodine contrast agents Creatinine>1.36 mg/dL Age < 18 years GFR less than 60ml/min/1.73m2 Body-Mass Index (BMI) greater than 30 kg/m2 I26 Pulmonary embolism Diagnosis Diagnosis Intervention group: Patients suspected of pulmonary embolism referred to Namazi Hospital (Shiraz) will be scanned by contrast agent reduction protocol. The amount of injected contrast agent to the patients in the intervention group will be 0.7 ml/kg of body weight. The Pecnograph contains 300mgI/ml (milligram iodine per millilitre) made in Iran and is the most widely available contrast agent. This contrast agent will be used to scan patients in the intervention group. These patients will be scanned by a 16-Slice LightSpeed GE Healthcare CT system, made in the USA, at 100kVp. The pulmonary CT Angio images of patients in the intervention group will be reconstructed by Filter Back Projection (FBP), made in the USA. FBP is a standard image reconstruction algorithm and is available in conventional CT systems. Conventional CT systems are used to scan patients in most hospitals affiliated with the Shiraz University of Medical Sciences. Control group: Patients suspected of pulmonary embolism referred to Namazi Hospital (Shiraz) will be scanned by standard protocol (pulmonary CT Angio). The amount of injected contrast agent to the patients in the control group will be 1.0 milliliter per kilogram of the patient’s body weight. The Pecnograph contains 300mgI/ml (milligram iodine per milliliter) made in Iran is the most widely available contrast agent. This contrast agent will be used to scan patients in the control group. The patients in the control group will be scanned by a 16-Slice LightSpeed GE Healthcare CT system, made in the USA, at 120kVp. The pulmonary CT Angio images of patients in the control group will be reconstructed by Filter Back Projection (FBP), made in the USA. FBP is a standard image reconstruction algorithm and is available in conventional CT systems. Conventional CT systems are used to scan patients in most hospitals affiliated with the Shiraz University of Medical Sciences. The objective image quality of pulmonary CT Angio will be determined by radiologists through a scoring system. The quantitative image quality will be determined by quantitative parameters such as Signal-to-Noise Ratio. Timepoint: The CT images will be sent to Picture Archiving and Communication System immediately after the scanning procedure completed. Then the qualitative and quantitative evaluation of the image quality of pulmonary CT Angio will be performed. Method of measurement: Quantitative pulmonary Computed Tomography angiography (CTA) image quality will be measured by the Signal-to-Noise Ratio (SNR). The mean CT density or CT- number of the main pulmonary arteries (left and right) will be measured. The CT-numbers will be measured by selecting the Region of Interest (ROI) inside the left and right main pulmonary arteries, filled with the contrast agent. This CT number is known as signal. The muscles surrounding the scapula is known as background, being a region without contrast agent. An ROI will be selected in the background. Then, the standard deviation of the CT-number will be measured for the background. These measured parameters will be used to calculate SNR. Qualitative pulmonary CT Angio (CTA) image quality will be measured by visual assessment. In this method, two expert radiologists will report the image quality using a scoring system. In this system measuring the image quality is measured in a scale of 5 in which the scores assigned as follows, (1) undiagnosable (2) limited diagnostic value (3) sufficient diagnostic value (4) good image quality (5) excellent diagnostic value. If the mean score equal to or greater than 3, it will be reported as an acceptable diagnostic value. Shiraz University of Medical Sciences Approved 2022-07-08 Ethics committee of Shiraz University of Medical Sciences Medical Imaging Research Centre, 8th Floor, Mohammad Rasolallah Research Tower, Khalili street Shiraz Fars Iran (Islamic Republic of)