Patient‐circumference‐adapted dose regulation in body computed tomography. a practical and flexible formula

Nyman, Ulf; Ahl, T. L.; Kristiansson, M; Nilsson, Lars‐Erik; Wettemark, Sara

doi:10.1080/02841850510021193

Cited by 27 publications

(23 citation statements)

References 15 publications

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“…Addendum: a dedicated computer program for calculation of patient circumference-adapted radiation dose regulation in body CT (when automatic exposure control systems are lacking) can be downloaded in Swedish and English versions from the internet, together with instructions and background scientific data [21] (http://omnimas. arwen.se.…”

Section: Limitations Of the Present Study And Drawbacks With The Low mentioning

confidence: 99%

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Eighty-peak kilovoltage 16-channel multidetector computed tomography and reduced contrast-medium doses tailored to body weight to diagnose pulmonary embolism in azotaemic patients

Holmquist

Nyman

2006

Eur Radiol

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The aim of this study was to assess the feasibility of minimising contrast-medium (CM) doses using 80-peak kilovoltage (kVp) 16-channel multidetector computed tomography (MDCT) with CM dose tailored to body weight, when diagnosing pulmonary embolism (PE) in azotaemic patients. Twenty-nine patients (68-93 years; 38-79 kg) with an estimated glomerular filtration rate of 12-49 ml/min underwent 80 kVp MDCT at a median dose of 200 mg iodine (I)/kg and 15 s injection time. Pulmonary artery (PA) enhancement where compared with our own reference material using 320 mg I/kg at 120 kVp and with reported figures in the literature at 120-140 kVp and a 42 g iodine CM dose. Median (1st and 3rd quartiles) values regarding CM dose were 12.2 (9.9-12.8) g iodine; density of left main and lower lobe segmental PA 339 (275-395) Hounsfield units (HU) and 354 (321-442) HU, respectively. Those enhancement values were similar to those obtained from the reference population at 120 kVp and those reported in the literature at 120-140 kVp. One patient had a transient increase in plasma creatinine. Three months' follow-up revealed deep venous thrombosis among 1/18 patients with negative results from computed tomography (CT). We conclude that 80 kVp 16-channel MDCT to diagnose PE in azotaemic patients may be performed with markedly reduced CM doses, implying a lesser risk for CM-induced nephropathy.

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Section: Limitations Of the Present Study And Drawbacks With The Low mentioning

confidence: 99%

“…The individual tube loading was calculated on a Microsoft Excel spreadsheet following measurement of the patient's widest thoracic circumference with a cloth measuring tape, generally at the level of the xiphoid process [21]. A "half-value thickness" (HVT) of 9 cm (28 cm circumference) was chosen, i.e.…”

Section: X-ray Tube Loadingmentioning

confidence: 99%

Eighty-peak kilovoltage 16-channel multidetector computed tomography and reduced contrast-medium doses tailored to body weight to diagnose pulmonary embolism in azotaemic patients

Holmquist

Nyman

2006

Eur Radiol

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“…No studies exist so far that provide information about the lowest tube current-time product possible in order to maintain a low image noise while maintaining diagnostic image quality with dualsource CT. In addition, circumference-adapted tube current regulation [28] or tube current-time product adaptation to body weight combined with online tube current modulation [29] has been shown to deliver chest examinations with lower dose and without loss of information. Another important approach for reducing radiation dose is the reduction of tube voltage [16], because the radiation dose varies with the square of the tube voltage.…”

Section: Study Limitationsmentioning

confidence: 99%

Radiation dose estimates in dual-source computed tomography coronary angiography

et al. 2007

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The purpose of this study was to quantify radiation dose parameters of dual-source CT coronary angiography. Eighty patients underwent contrast-enhanced, retrospectively ECG-gated dual-source CT coronary angiography with heart rate-adapted ECG pulsing using two algorithms: In 40 patients, the tube current was reduced to 20% (A min1 ) of the normal tube current (A max ) outside the pulsing window; in 40 patients tube current was reduced to 4% (A min2 ) of A max . Mean CTDI vol in the A min1 group was 45.1±3.6 mGy; the mean CTDI vol in the A min2 group was 39.1± 3.2 mGy, with CTDI vol in the A min2 group being significantly reduced when compared to the A min1 group (P< 0.001). A significant negative correlation was found between CTDI vol and heart rate in group A min1 (r=−0.82, P< 0.001), whereas no correlation was found between CTDI vol and heart rate in group A min2 (r=−0.066). Using the conversion coefficient for the chest, dual-source CT coronary angiography resulted in an estimated mean effective dose of 8.8 mSv in the A min1 group and 7.8 mSv in the A min2 . Radiation exposure of dual-source CT coronary angiography using an ECG-pulsing protocol reducing the tube current to 20% significantly decreases with increasing heart rates, despite using wider pulsing windows at higher heart rates. When using a protocol with reduced tube current of 4%, the radiation dose is significantly lower, irrespective of the heart rate.

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“…Instead reference x-ray tube loading was based on a patient with an 88-cm circumference [15]. The individual tube loading was calculated with the help of a computer program (http:// www.arwen.se/radiologi/omnimas) following measurement of the widest thoracic circumference with a tape measure.…”

Section: Methodsmentioning

confidence: 99%

“…A half-value thickness (HVT) of 9 cm was chosen, i.e. the change in object diameter that doubled or halved the mAs setting [15].…”

Section: Methodsmentioning

confidence: 99%

Ultralow contrast medium doses at CT to diagnose pulmonary embolism in patients with moderate to severe renal impairment: a feasibility study

2009

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Patient‐circumference‐adapted dose regulation in body computed tomography. a practical and flexible formula

Abstract: Until fully automatic automatic exposure control systems have been introduced, applying the formula in a computer program provides the radiologist with an easy, quick, flexible, and practical instrument for reasonably good patient-sized adjusted exposure levels in clinical practice.

Cited by 27 publications

References 15 publications

Eighty-peak kilovoltage 16-channel multidetector computed tomography and reduced contrast-medium doses tailored to body weight to diagnose pulmonary embolism in azotaemic patients

Eighty-peak kilovoltage 16-channel multidetector computed tomography and reduced contrast-medium doses tailored to body weight to diagnose pulmonary embolism in azotaemic patients

Radiation dose estimates in dual-source computed tomography coronary angiography

Ultralow contrast medium doses at CT to diagnose pulmonary embolism in patients with moderate to severe renal impairment: a feasibility study

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