PATIENT SIZE BASED GUIDING EQUATIONS FOR AUTOMATIC mAs AND kVp SELECTIONS IN GENERAL MEDICAL X-RAY PROJECTION RADIOGRAPHY

Zheng, Xiaoming

doi:10.1093/rpd/ncw246

Cited by 7 publications

(14 citation statements)

References 18 publications

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“…An ideal value of n=3.33 was suggested for the 15% 'rule of thumb' (Ching et al 2014), i.e. for a 15% increase of kVp, half the mAs, in our earlier study (Zheng 2016a). It was also suggested that the dose at the body centre should be taken as dose reference rather than detector absorbed dose, or dose at the exit surface (Zheng 2016a).…”

Section: Discussionmentioning

confidence: 84%

“…In our recent works (Zheng 2016a(Zheng , 2016b, the averaged powers of x-ray tube dose output were employed in the derivations of governing equations for automatic selection of optimal scan parameters, mAs and kVp, in clinical x-ray imaging including CT (Zheng 2016b) and computed radiography or direct digital radiography (Zheng 2016a). The x-ray tube dose power n was assumed to be an imaging system dependent-constant together with the size specific dose correction factor constant γ in these mathematical derivations (Zheng 2016a(Zheng , 2016b.…”

Section: Introductionmentioning

confidence: 99%

“…The x-ray tube dose power n was assumed to be an imaging system dependent-constant together with the size specific dose correction factor constant γ in these mathematical derivations (Zheng 2016a(Zheng , 2016b. The accuracies of these equations depend on the exact values of the parameters n and γ (Zheng 2016a(Zheng , 2016b. The purpose of this work was to examine the dependence of the dose power on patient size in clinical x-ray imaging including CT and radiographic imaging.…”

Section: Introductionmentioning

confidence: 99%

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Size effect on dose output in phantoms of x-ray tubes in medical x-ray imaging

Zheng

Nardi

Murray

2017

Biomed. Phys. Eng. Express

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The purpose of this work was to study how patient size affects the exponent of the power law relating dose to x-ray tube potential in clinical x-ray imaging using phantoms. Computed tomography (CT) dose phantoms of 16 cm and 32 cm in diameter were used to model children and adults respectively. A Fujifilm digital radiographic imaging system and a GE Discovery HD 750 CT scanner were employed to image both phantoms. For the Fujifilm radiographic imaging system, doses were measured at various locations of entrance, centre, exit as well as side locations of the phantoms using a PTW DIADOS diagnostic dosimeter. Standard procedure was employed for CT dose measurements for the GE CT scanner. X-ray exposures were varied by employing various tube voltages kVp and tube current-time product or mAs. This study found that the exponent in dose power law in phantoms increases as phantom size increases. Doses measured at body centres have lower uncertainties than those at x-ray exit surfaces. The power law exponent in phantoms was found to be a linear function of the depth from the entrance surface consistent with theoretical prediction and data from the literature. These results led to both kVp and body size dependent governing equations for the variations of imaging parameters in CT and radiographic imaging. These equations provide better estimates in guiding selection of optimal scan parameters in clinical x-ray imaging.

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Section: Discussionmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Size effect on dose output in phantoms of x-ray tubes in medical x-ray imaging

Zheng

Nardi

Murray

2017

Biomed. Phys. Eng. Express

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“…Faktor eksposi dapat dipilih dengan menyesuaikan tiap-tiap ukuran bagian tubuh dan kondisi patologis tertentu sehingga memperoleh kualitas citra sebaik mungkin (Long et al, 2019). Pada pasien yang memiliki pelvis tebal (lebih dari 20 cm) dianjurkan untuk menambah kondisi faktor eksposi dengan tujuan agar menghasilkan citra yang optimal sehingga dapat digunakan radiolog dalam melakukan diagnosa (Zheng, 2017;Metaxas et al, 2019).…”

Section: Pendahuluanunclassified

DOSE OPTIMIZATION WITH mAs REDUCTION OF 15% USING COMPUTED RADIOGRAPHY ON RADIOGRAPHIC EXAMINATIONS PELVIC AP PROJECTION

et al. 2022

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Background: Routine pelvic radiograph examination commonly performed in diagnostic radiology services is a pelvic examination of anteroposterior projection (AP). This results in direct exposure to ionizing radiation to the internal organs in the lower abdomen, especially the reproductive organs. Purpose: Optimizing the dosage of AP projection pelvic radiographs. Method: Research is conducted quantitatively and used experimental approach with an analysis of 15% mAs reduction from the standard mAs value on AP projection pelvic examination on radiation dose and image quality using anthropomorphic phantoms. The radiation dose analysis uses the exposure index indicator. In contrast, the image quality uses the Visual Grading Analysis method, then it was continued with the Kappa Cohens test to determine the level of agreement between 2 respondents. Result: The exposure factor with the mAs value reduced by 15% from the standard exposure factor on the AP projection pelvic radiography affected the decrease in the value exposure index. The EI value generated from the optimization exposure factor shows a decrease to 300 EI, which means the dose produced is only half of the standard exposure factor dose but still produces an acceptable image, as evidenced by the VGA score. As an assessment of image quality. In this study, there was no significant difference with range VGA scores 1,7. Besides that, the test had the Kappa Cohens level of agreement with a value of 0.5-0.8. Conclusion: All images resulting from the 15% mAs value reduction variation can be used as a diagnostic assessment.

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“…Dalam penggunaan CR, perlu diperhatikan beberapa faktor yang mempengaruhi yang salah satunya penggunaan filter pesawat sinar-X berdasarkan penelitian oleh bahwa dengan peningkatan nilai filter diikuti dengan kenaikan nilai EI (Ekpo et al, 2014). Penggunaan nilai mAs dapat disesuaikan dengan ukuran tubuh pasien dimana apabila terjadi peningkatan 1 cm tubuh pasien maka dikompensasi dengan penambahan 15% nilai mAs (Zheng, 2017), disarankan bahwa pada pasien dengan ketebalan tubuh standar sebaiknya menggunakan teknik kV standar dengan dengan menyeimbangkan dosis radiasi yang diterima dan kualitas citra yang dihasilkan, kemudian untuk pasien dengan ketebalan tubuh lebih besar, maka dapat menggunakan teknik kV tinggi dengan tetap mengutamakan upaya optimisasi agar tercapai konsep ALARA (Metaxas et al, 2019). Selain itu, pengalaman klinisi radiografer menjadi penentuan pemilihan faktor eksposi dan analisa kualitas citra yang dihasilkan, dimana radiografer dapat mengupayakan optimasi citra dengan pertimbangan pemilihan faktor eksposi untuk EI yang optimal dari ukuran tubuh, peralatan CR dan pesawat sinar-X yang digunakan.…”

Section: Pembahasanunclassified

Analysis Exposure Index as an Optimization Effort on Examination Chest Posterior Anterior

Irsal¹,

Syuhada

Ananda³

et al. 2020

J Vocat Heal Stud

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Background: Radiographers are responsible for producing image quality which can provide accurate diagnostic information by considering the lowest possible radiation dose according to the As Low As Reasonably Achievable (ALARA) principle. Participation between radiographers and medical physicists is needed in optimizing efforts to control the selection of exposure factors by the required clinical radiographic examination. Purpose: To analyze the exposure index on examination chest posterior-anterior. Methods: Quantitative descriptive by analyzing the percentage of exposure index results used in chest PA radiographs as an effort to optimize: image quality and radiation dose indicators on chest PA examinations. Results: Optimization of exposure percentage results of 68%, 25% underexposure, 4% underexposure, 2% overexposure, 1% overexposure (noise). Radiographers have tried to optimize: image quality and image radiation dose by selecting exposure factors that are tailored to the patient’s condition and maximizing post-processing for increased quality. Conclusion: In optimizing the CR imaging system, it is necessary to understand exposure index, this is related to the underexposed, optimal, and overexposed categories, besides radiographers can take advantage of post-processing to improve image quality.

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PATIENT SIZE BASED GUIDING EQUATIONS FOR AUTOMATIC mAs AND kVp SELECTIONS IN GENERAL MEDICAL X-RAY PROJECTION RADIOGRAPHY

Cited by 7 publications

References 18 publications

Size effect on dose output in phantoms of x-ray tubes in medical x-ray imaging

Size effect on dose output in phantoms of x-ray tubes in medical x-ray imaging

DOSE OPTIMIZATION WITH mAs REDUCTION OF 15% USING COMPUTED RADIOGRAPHY ON RADIOGRAPHIC EXAMINATIONS PELVIC AP PROJECTION

Analysis Exposure Index as an Optimization Effort on Examination Chest Posterior Anterior

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