In vivo dosimetry for estimation of effective doses in multislice CT coronary angiography

Journal Article · Mon Oct 15 04:00:00 EDT 2007 · Medical Physics

DOI:https://doi.org/10.1118/1.2766758· OSTI ID:21032787

De Denaro, M; Bregant, P; Severgnini, M; De Guarrini, F ^[1]

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1. Department of Medical Physics, A.O.U. 'Ospedali Riuniti' Trieste (Italy)

In vivo dosimetry represents a technique that has been widely employed to evaluate the dose to the patient mainly in radiotherapy. Considering the increment in dose to the population due to new high-dose multislice CT examinations, such as coronary angiography, it is becoming important to more accurately know the dose to the patient. The desire to know patient dose extends even to radiological examinations. Thermoluminescent dosimeters are considered the gold standard for in vivo dosimetry, but their use is time consuming. A rapid, less labor-intensive method has been developed to perform in vivo dosimetry using radiochromic film positioned next to the patient's skin. Multislice CT scanners allow the estimation of the effective dose to the patient from the dose length product (DLP) parameter, the value of which is displayed on the acquisition console, simply multiplying the DLP by published conversion factors. The method represents only an approximation based on standard size circular phantoms and neglects the actual size of the patient. More accurate evaluations can be carried out using software-based Monte Carlo simulations. However, these methods do not consider possible dose reduction techniques, such as automatic tube-current modulation. For 22 patients effective doses measured by in vivo dosimetry and calculated by software were compared. The technique of using in vivo dosimetry measured with radiochromic film appears a promising procedure for improving the assessment of the effective dose to the patient.

• OSTI ID: 21032787
• Journal Information: Medical Physics, Journal Name: Medical Physics Journal Issue: 10 Vol. 34; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

61 RADIATION PROTECTION AND DOSIMETRY
BIOMEDICAL RADIOGRAPHY
COMPUTERIZED TOMOGRAPHY
CORONARIES
DOSIMETRY
IN VIVO
MONTE CARLO METHOD
PATIENTS
PHANTOMS
RADIATION DOSES
RADIOTHERAPY
THERMOLUMINESCENT DOSEMETERS