Absorbed Radiation Dose in Radiosensitive Organs Using 64- and 320-Row Multidetector Computed Tomography: A Comparative Study

Aim. To determine absorbed radiation dose (ARD) in radiosensitive organs during prospective and full phase dose modulation using ECG-gated MDCTA scanner under 64- and 320-row detector modes. Methods:. Female phantom was used to measure organ radiation dose. Five DP-3 radiation detectors were used to measure ARD to lungs, breast, and thyroid using the Aquilion ONE scanner in 64- and 320-row modes using both prospective and dose modulation in full phase acquisition. Five measurements were made using three tube voltages: 100, 120, and 135 kVp at 400 mA at heart rate (HR) of 60 and 75 bpm for each protocol. Mean acquisition was recorded in milligrays (mGy). Results:. Mean ARD was less for 320-row versus 64-row mode for each imaging protocol. Prospective EKG-gated imaging protocol resulted in a statistically lower ARD using 320-row versus 64-row modes for midbreast (6.728 versus 19.687 mGy, P < 0.001), lung (6.102 versus 21.841 mGy, P < 0.001), and thyroid gland (0.208 versus 0.913 mGy; P < 0.001). Retrospective imaging using 320- versus 64-row modes showed lower ARD for midbreast (10.839 versus 43.169 mGy, P < 0.001), lung (8.848 versus 47.877 mGy, P < 0.001), and thyroid gland (0.057 versus 2.091 mGy; P < 0.001). ARD reduction was observed at lower kVp and heart rate. Conclusions:. Dose reduction to radiosensitive organs is achieved using 320-row compared to 64-row modes for both prospective and retrospective gating, whereas 64-row mode is equivalent to the same model 64-row MDCT scanner

Influence of Image Acquisition on Radiation Dose and Image Quality: Full versus Narrow Phase Window Acquisition Using 320 MDCT

Purpose. To compare radiation dose and image quality using predefined narrow phase window versus complete phase window with dose modulation during R-R using 320-row MDCTA. Methods:. 114 patients underwent coronary CTA study using 320-row MDCT scanner. 87 patients with mean age (61 + 13 years), mean BMI (29 + 6), and mean heart rate (HR) (58 + 7 bpm) were imaged at predefined 66–80% R-R interval and then reconstructed at 75% while 27 patients with mean age (63 + 16 years), mean BMI (28 + 5), and mean HR (57 + 7 bpm) were scanned throughout the complete R-R interval with tube current modulation. The effective dose (ED) was calculated from dose length product (DLP) and conversion k (0.014 mSv/mGy/cm). Image quality was assessed using a three-point ordinal scale (1 = excellent, 2 = good, and 3 = nondiagnostic). Results:. Both groups were statistically similar to each other with reference of HR (P = 0.59), BMI (P = 0.17), and tube current mAs (P = 0.68). The median radiation dose was significantly higher in those scanned with complete R-R phase window versus narrow phase window (P < 0.0001). Independently of patient and scan parameters, increased phase window was associated with higher radiation dose (P < 0.001). Image quality was better among those scanned with narrow phase window versus complete phase window (P < 0.0001). Conclusion:. Our study supports that good HR control and predefined narrow window acquisition result in lower radiation dose without compromising diagnostic image quality for coronary disease evaluation

Utility of CT angiography in cervical spine trauma: analysis of radiation and cost

Purpose: Vertebral artery injuries (VAIs) can be seen in cervical injuries. This investigation was conducted to assess the impact of head and neck computed tomography (CT) angiography (CTA) on planning treatment of vertebral artery injuries, if these tests were ordered appropriately, and to estimate cost and associated exposure to radiation and contrast material. Methods: This retrospective review included all patients who underwent CT of the cervical spine and CTA of the head and neck from March 2011 to October 2012 at a single institution. Patients were divided into two groups, those with and those without cervical spine fracture appreciated on CT of the cervical spine. The frequency of vascular injury on CTA in those with a cervical fracture was assessed. The frequency of vascular injury treatment and modifications owed to a positive CTA of head and neck were also assessed. A study was considered appropriate if it was ordered in accordance with the modified Denver Screening criteria. Effective radiation dose (mSv) was calculated by multiplying dose length product (DLP) from the scanner with the standard conversion coefficient (k) (k = 0.0021 mSv/mGy x cm).Results: In the 387 CTAs of head and neck, a cervical injury was recorded in 128 patients. Twenty CTA scans were correctly ordered for non-spinal indications, and 19 were ordered off protocol. CTA was found positive in 1 patient for whom the imaging was off protocol and 1 for whom the clinical indication was non-cervical. There were 19 positive CTA cases of head and neck, none of which underwent surgical intervention. CTA was positive in 13 of 48 patients who had suffered a C2 fracture; this accounted for 13 of the 19 positive CTA studies (p &lt; 0.01). Estimated fee for CTA was $3783, and radiation exposure was 4 mSv with a standard deviation (±1.3). Conclusion: CTA of head and neck ordered off an institutional imaging protocol has a low probability of being positive. Adherence to protocols for CTA of head and neck can reduce costs and decrease unnecessary exposure to radiation and contrast medium.---------------------------------------Cite this article as:Shuaib W, Khan AA, Mehta AS, Vijayasarathi A, Hidalgo J. Utility of CT angiography in cervical spine trauma: analysis of radiation and cost. Int J Cancer Ther Oncol 2014; 2(4):02043. DOI: 10.14319/ijcto.0204.

Radiation exposure for coronary artery calcium score at prospective 320 row multi-detector computed tomography

Purpose:To date there is extensive data on the radiation dose for assessing coronary artery calcium scores (CACS) with 4-64 row multidetector MDCT. However with the advent of 320 row MDCT, the entire heart can be imaged in one beat and thus potentially reduce the radiation dose. The aim of this study was to evaluate radiation dose for CACS on low-dose prospective EKG-triggered 320 row MDCT.Materials and Methods: Informed consent for this retrospective HIPAA-compliant study was waived and approved by our institution’s institutional review board IRB. One hundred and sixty eight consecutive patients (Male 133 (79%): female 35 (21%), mean body mass index BMI 29±5 and mean heart rate 58± bpm) underwent coronary calcium scoring with prospective gating. The scan parameters were 300 mA, 120 kVp, volume scan length (VSL) 160 mm, gantry rotation 0.350 msec and 320 x 0.5 mm detectors at 320 MDCT. Beta blockers were given to patients in a case heart rate HR &gt; 65 bpm. The effective dose (ED) estimates were calculated for all patients from the dose length product and the conversion factor k (0.014 mSv/mGy/cm) as recommended by current guidelines.Results: The mean SD radiation was 1.89±0.79 mSv. Overall the range varied from 0.28-2.48 mSv. The radiation was significantly less in females as compared to males (2.02±0.73 vs. 1.41±0.87, p&lt;0.0001). No differences were noted whether HR was &lt;60 vs. &gt;=60 bpm (1.87±0.79 vs. 1.77±0.84 mSv, p=0.45). On the other hand a higher radiation was noted among obese individuals as compared to those with BMI&lt;30 (1.84±0.82 vs. 1.91±0.80 mSv, p=0.62).Conclusion: Radiation dose obtained from 320-MDCT is similar to those obtained with 4-64 row MDCT. Further studies are needed to assess the feasibility of further lowering the tube current and tube voltage.------------------------------------------------Cite this article as:Khosa F, Khan A, Shuaib W, Clouse M, Budoff M, Blankstein R, Nasir K. Radiation exposure for coronary artery calcium score at prospective 320 row multi-detector computed tomography. Int J Cancer Ther Oncol 2013; 1(2):01023.DOI: http://dx.doi.org/10.14319/ijcto.0102.

Rate of EGFR mutation in patients with pulmonary adenocarcinoma

Purpose: Contemporary literature on lung adenocarcinoma has demonstrated a genetic difference of the epidermal growth factor receptor (EGFR) pathway conferring to ethnicity, such as higher frequency of activated EGFR mutations in East Asian population. This information is missing in some developing countries, and we intend to address this gap in the literature. Methods: We examined the rate of EGFR mutations among Pakistani patients with adenocarcinoma of the lung. Fine-needle aspiration samples were gathered from 73 patients. Polymerase chain reaction was performed on extracted DNA for mutational analysis of EGFR exons 19 and 21. Results: EGFR mutations were discovered in 18 of 73 (24.6%) patients. We did not find any significant difference in EGFR mutation rate with regard to patient's age, sex, smoking history, clinical stage of lung cancer, subtypes of adenocarcinoma, and tumor differentiation. Conclusion: Our investigation shows that the EGFR mutation rate in our patient population with adenocarcinoma of the lung was higher than in African-American, Arabian, and white Caucasian patients, and was lower than the East Asian population

Anatomy of success: 100 most cited articles in diabetes research

Introduction: The number of citations an article receives is an important indication of its impact and its contribution to academia. There is a paucity of literature concerning top article citations in diabetes. The main objective of this investigation was to bridge this gap and to provide readers with a practical guide in evaluating diabetes literature. Methods: Scopus Library was searched to determine the citations of all published diabetes articles. A total of 100 articles were included in our investigation under the subject category ‘Diabetes, diabetes mellitus, and diabetics’. Two databases were used to extract citations. We did not apply any time restriction in our search. The top 100 cited articles were selected and analyzed by two independent investigators. We extracted immediacy index from ResearchGate. Results: The journal with the highest number of top 100 cited articles was The New England Journal of Medicine with 23, followed by 22 in Diabetes Care . The top article on the list received 17,779 citations. A statistically significant association was found between the journal impact factor and the number of top 100 cited articles ( p < 0.005). The United States had the highest number of articles (59). Contrary to bibliometric analyses published in other medical fields, the largest subset of the diabetes articles ( n = 54) were published in the 10-year period between 2000 and 2009. Conclusion: Our analysis provides an insight on the citation frequency of top cited articles published in diabetes to help recognize the quality of the works, discoveries and the trends steering the study of diabetes

Utility of CT angiography in cervical spine trauma: analysis of radiation and cost

Purpose: Vertebral artery injuries (VAIs) can be seen in cervical injuries. This investigation was conducted to assess the impact of head and neck computed tomography (CT) angiography (CTA) on planning treatment of vertebral artery injuries, if these tests were ordered appropriately, and to estimate cost and associated exposure to radiation and contrast material. Methods: This retrospective review included all patients who underwent CT of the cervical spine and CTA of the head and neck from March 2011 to October 2012 at a single institution. Patients were divided into two groups, those with and those without cervical spine fracture appreciated on CT of the cervical spine. The frequency of vascular injury on CTA in those with a cervical fracture was assessed. The frequency of vascular injury treatment and modifications owed to a positive CTA of head and neck were also assessed. A study was considered appropriate if it was ordered in accordance with the modified Denver Screening criteria. Effective radiation dose (mSv) was calculated by multiplying dose length product (DLP) from the scanner with the standard conversion coefficient (k) (k = 0.0021 mSv/mGy x cm).Results: In the 387 CTAs of head and neck, a cervical injury was recorded in 128 patients. Twenty CTA scans were correctly ordered for non-spinal indications, and 19 were ordered off protocol. CTA was found positive in 1 patient for whom the imaging was off protocol and 1 for whom the clinical indication was non-cervical. There were 19 positive CTA cases of head and neck, none of which underwent surgical intervention. CTA was positive in 13 of 48 patients who had suffered a C2 fracture; this accounted for 13 of the 19 positive CTA studies (p &lt; 0.01). Estimated fee for CTA was $3783, and radiation exposure was 4 mSv with a standard deviation (±1.3). Conclusion: CTA of head and neck ordered off an institutional imaging protocol has a low probability of being positive. Adherence to protocols for CTA of head and neck can reduce costs and decrease unnecessary exposure to radiation and contrast medium.---------------------------------------Cite this article as:Shuaib W, Khan AA, Mehta AS, Vijayasarathi A, Hidalgo J. Utility of CT angiography in cervical spine trauma: analysis of radiation and cost. Int J Cancer Ther Oncol 2014; 2(4):02043. DOI: 10.14319/ijcto.0204.3</p

Reply to Awad, M.M. Comment on &ldquo;Alam et al. Numerical Simulation of Homogeneous&ndash;Heterogeneous Reactions through a Hybrid Nanofluid Flowing over a Rotating Disc for Solar Heating Applications. Sustainability 2021, 13, 8289&rdquo;

This write-up presents a closure to the comments of Awad, M.M. (2021) on the paper &ldquo;Numerical Simulation of Homogeneous&ndash;Heterogeneous Reactions through a Hybrid Nanofluid Flowing over a Rotating Disc for Solar Heating Applications&rdquo; (Alam et al., 2021). The authors have addressed each of the comments in detail to uphold the correctness of the mathematical formulation together with the pertinent results presented in our published article